U.S. patent application number 14/376277 was filed with the patent office on 2015-01-01 for heat exchanger.
The applicant listed for this patent is DENSO CORPORATION. Invention is credited to Nobuharu Kakehashi, Yoshiki Katoh.
Application Number | 20150000327 14/376277 |
Document ID | / |
Family ID | 48904924 |
Filed Date | 2015-01-01 |
United States Patent
Application |
20150000327 |
Kind Code |
A1 |
Kakehashi; Nobuharu ; et
al. |
January 1, 2015 |
HEAT EXCHANGER
Abstract
A heat exchanging portion and tank portions are formed by
bonding plate members. The tank portion is provided with a
refrigerant inlet allowing a refrigerant to flow into a refrigerant
tank space, a refrigerant outlet allowing the refrigerant to flow
from the refrigerant tank space, a heat medium inlet allowing a
heat medium to flow into a heat medium tank space, and a heat
medium outlet allowing the heat medium to flow from the heat medium
tank space. At least one of the refrigerant inlet, the refrigerant
outlet, the heat medium inlet, and the heat medium outlet is
disposed between both ends of the tank portions in a tube stacking
direction of refrigerant tubes and heat medium tubes.
Inventors: |
Kakehashi; Nobuharu;
(Toyoake-city, JP) ; Katoh; Yoshiki; (Kariya-city,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DENSO CORPORATION |
Kariya-city, Aichi-pref. |
|
JP |
|
|
Family ID: |
48904924 |
Appl. No.: |
14/376277 |
Filed: |
January 31, 2013 |
PCT Filed: |
January 31, 2013 |
PCT NO: |
PCT/JP2013/000521 |
371 Date: |
August 1, 2014 |
Current U.S.
Class: |
62/434 |
Current CPC
Class: |
F02M 26/28 20160201;
F28D 2021/0031 20130101; B60H 1/32281 20190501; F01P 2050/24
20130101; F25D 17/02 20130101; F28D 9/005 20130101; B60H 1/004
20130101; B60L 2240/545 20130101; B60K 2001/003 20130101; F28D
2021/0084 20130101; F02B 29/0443 20130101; H01M 10/625 20150401;
Y02T 10/70 20130101; F28F 1/00 20130101; B60L 2240/34 20130101;
F28F 9/26 20130101; H01M 10/613 20150401; H01M 10/6556 20150401;
F28F 9/02 20130101; F28D 2021/008 20130101; Y02E 60/10 20130101;
B60H 1/143 20130101; Y02T 10/12 20130101; F28D 9/0043 20130101;
F28D 9/0093 20130101; F28D 2021/0094 20130101; F28F 27/02 20130101;
F28F 9/0246 20130101 |
Class at
Publication: |
62/434 |
International
Class: |
F25D 17/02 20060101
F25D017/02; F28F 1/00 20060101 F28F001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 2, 2012 |
JP |
2012-020905 |
Apr 3, 2012 |
JP |
2012084444 |
Jan 15, 2013 |
JP |
2013-004966 |
Claims
1. A heat exchanger comprising: a heat exchanging portion
configured by stacking a plurality of refrigerant tubes through
which a refrigerant in a vapor-compression refrigeration cycle
flows, and a plurality of heat medium tubes through which a heat
medium flows to exchange heat with the refrigerant; and a tank
portion provided with at least one of a refrigerant tank space
adapted to collect or distribute the refrigerant with respect to
the refrigerant tubes, and a heat medium tank space adapted to
collect or distribute the heat medium with respect to the heat
medium tubes, wherein the heat exchanging portion and the tank
portion are formed by bonding plate members, the heat exchanging
portion includes a first heat exchanging portion in which heat is
exchanged between the heat medium and the refrigerant on a
high-pressure side of the vapor-compression refrigeration cycle,
and a second heat exchanging portion in which heat is exchanged
between the heat medium and the refrigerant on a low-pressure side
of the vapor-compression refrigeration cycle, the tank portion is
provided with a refrigerant inlet that allows the refrigerant to
flow into the refrigerant tank space, a refrigerant outlet that
allows the refrigerant to flow from the refrigerant tank space, a
heat medium inlet that allows the heat medium to flow into the heat
medium tank space, and a heat medium outlet that allows the heat
medium to flow from the heat medium tank space, and at least one of
the refrigerant inlet, the refrigerant outlet, the heat medium
inlet, and the heat medium outlet is disposed between both ends of
the tank portion in a tube stacking direction of the refrigerant
tubes and the heat medium tubes.
2. The heat exchanger according to claim 1, wherein at least one of
the refrigerant inlet, the refrigerant outlet, the heat medium
inlet, and the heat medium outlet is opened between both the ends
in a direction perpendicular to the tube stacking direction.
3. The heat exchanger according to claim 1, wherein at least one of
the refrigerant inlet, the refrigerant outlet, the heat medium
inlet, and the heat medium outlet is formed by multiple members
disposed between the plate members.
4. The heat exchanger according to claim 3, wherein the multiple
members are disposed at a boundary between the first heat
exchanging portion and the second heat exchanging portion.
5. The heat exchanger according to claim 1, wherein the plate
members are disposed opposite to each other in the tube stacking
direction, with a boundary between the first heat exchanging
portion and the second heat exchanging portion, as a center.
6. The heat exchanger according to claim 1, wherein an auxiliary
heat exchanging portion that exchanges heat between a first fluid
and a second fluid is provided between the first heat exchanging
portion and the second heat exchanging portion, wherein the first
fluid is the refrigerant or the heat medium, the second fluid is
the refrigerant or the heat medium, and at least one of the first
fluid and the second fluid is the refrigerant or the heat medium
flowing from at least one of the first heat exchanging portion and
the second heat exchanging portion.
7. The heat exchanger according to claim 6, wherein the auxiliary
heat exchanging portion is configured by stacking first fluid tubes
adapted to allow the first fluid to flow therethrough, and second
fluid tubes adapted to allow the second fluid to flow therethrough,
the first fluid tube are used as the refrigerant tubes or the heat
medium tubes, the second fluid tubes are used as the refrigerant
tubes or the heat medium tubes, and one of the first fluid tubes is
sandwiched between adjacent two of the second fluid tubes.
8. The heat exchanger according to claim 6, wherein the first fluid
is the refrigerant or the heat medium flowing from the first heat
exchanging portion, and the second fluid is the refrigerant or the
heat medium flowing from the second heat exchanging portion.
9. The heat exchanger according to claim 8, wherein the tank
portion is provided with a first fluid tank space adapted to allow
the first fluid flowing from the first heat exchanger to enter the
auxiliary heat exchanging portion, and a second fluid tank space
adapted to allow the second fluid flowing from the second heat
exchanging portion to enter the auxiliary heat exchanging portion,
the first fluid tank space is the refrigerant tank space or the
heat medium tank space, the second fluid tank space is the
refrigerant tank space or the heat medium tank space, a part of the
first fluid tank space corresponding to the first heat exchanging
portion is superimposed on a part of the first fluid tank space
corresponding to the auxiliary heat exchanging portion when being
viewed from the tube stacking direction, and a part of the second
fluid tank space corresponding to the second heat exchanging
portion is superimposed on a part of the second fluid tank space
corresponding to the auxiliary heat exchanging portion when being
viewed from the tube stacking direction.
10. The heat exchanger according to claim 1, wherein at least one
of the refrigerant outlet and the heat medium outlet is disposed
between (i) a first boundary serving as a boundary between the
first heat exchanging portion and the auxiliary heat exchanging
portion, and (ii) a second boundary serving as a boundary between
the auxiliary heat exchanging portion and the second heat
exchanging portion.
11. The heat exchanger according to claim 1, wherein at least one
of the refrigerant outlet and the heat medium outlet is configured
by multiple members disposed between the plate members, and the
multiple members are disposed at least one of (i) between the first
heat exchanging portion and the auxiliary heat exchanging portion,
and (ii) between the auxiliary heat exchanging portion and the
second heat exchanging portion.
12. The heat exchanger according to claim 11, wherein the multiple
members extend from one end to the other end of the plate member in
a longitudinal direction of the refrigerant tubes and the heat
medium tubes, and wherein outlets formed by the multiple members
among the refrigerant outlet and the heat medium outlet are
disposed at both sides of one end and the other end of the
refrigerant tubes and the heat medium tubes.
13. The heat exchanger according to claim 1, wherein the plate
members are disposed opposite to each other in the tube stacking
direction with the multiple members centered.
14. The heat exchanger according to claim 1, wherein a
decompression device that decompresses the refrigerant flowing from
the first heat exchanger is disposed between the first heat
exchanging portion and the second heat exchanging portion, and the
refrigerant decompressed by the decompression device flows into the
second heat exchanging portion.
15. The heat exchanger according to claim 14, wherein the
refrigerant tank space is provided with a first tank space for the
refrigerant adapted to allow the refrigerant flowing from the first
heat exchanging portion to enter the decompression device, and a
second tank space for the refrigerant adapted to allow the
refrigerant flowing from the decompression device to enter the
second heat exchanging portion, and wherein the first tank space
for the refrigerant and the second tank space for the refrigerant
are superimposed on each other when being viewed from the tube
stacking direction.
16. The heat exchanger according to claim 15, wherein the
decompression device includes a decompression flow path
decompressing the refrigerant flowing from the first heat
exchanging portion and allowing the decompressed refrigerant to
enter the second heat exchanging portion, and the first tank space
for the refrigerant, the decompression flow path, and the second
tank space for the refrigerant are arranged side by side linearly
in the tube stacking direction.
17. The heat exchanger according to claim 15, wherein the
decompression device includes a decompression flow path
decompressing the refrigerant flowing from the first heat
exchanging portion and allowing the decompressed refrigerant to
enter the second heat exchanging portion, an inlet and an outlet of
the decompression flow path are disposed at different positions
when being viewed from the tube stacking direction, a refrigerant
flow path formation member forming a refrigerant flow path through
which the refrigerant flows is provided at least one of between the
first tank space for the refrigerant and the inlet, and between the
outlet and the second tank space for the refrigerant, and the
refrigerant flow path is non-parallel to the tube stacking
direction.
18. The heat exchanger according to claim 1, wherein a cavity
formation portion is provided between the first heat exchanging
portion and the second heat exchanging portion to form a cavity
that suppresses heat transfer between the first heat exchanging
portion and the second heat exchanging portion.
19. The heat exchanger according to claim 18, wherein the cavity
formation portion is formed by bonding a plurality of member parts
disposed between the plate members.
20. The heat exchanger according to claim 18, wherein the plate
members are disposed opposite to each other in the first heat
exchanging portion and in the second heat exchanging portion, and
the cavity formation portion is formed by bonding the two plate
members which are disposed opposite to each other in the tube
stacking direction.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] The application is based on Japanese Patent Applications No.
2012-020905 filed on Feb. 2, 2012, No. 2012-084444 filed on Apr. 3,
2012, and No. 2013-004966 filed on Jan. 15, 2013, the contents of
which are incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present disclosure relates to a heat exchanger for
exchanging heat between a refrigerant and a heat medium.
BACKGROUND OF THE INVENTION
[0003] Conventionally, as disclosed in Patent Document 1, there is
proposed a heat controller for cooling a motor generator, an
inverter, a battery and a vehicle compartment of an electric
vehicle.
[0004] The heat controller in the related art includes a cooling
circuit for allowing a coolant for cooling the motor generator and
the inverter to circulate therethrough, a first circulation circuit
for allowing a coolant for cooling the battery and vehicle
compartment to circulate therethrough, and a second circulation
circuit for allowing a coolant passing through an outdoor heat
exchanger and exchanging heat with outside air to circulate
therethrough.
[0005] Further, the heat controller includes a first valve for
connecting or disconnecting between the cooling circuit and the
first circulation circuit, a second valve for connecting or
disconnecting the cooling circuit to either the first circulation
circuit or second circulation circuit, and a third valve for
connecting or disconnecting between the cooling circuit and the
second circulation circuit. The respective valves are controlled to
switch the subject of connection of the cooling circuit between the
first and second circulation circuits.
[0006] Heat can be transferred by a heat transfer device between
the coolant circulating through the first circulation circuit and
the coolant circulating through the second circulation circuit. The
heat transfer device transfers the heat from the coolant at a low
temperature to the coolant at a high temperature between the
coolants in the first and second circulation circuits.
[0007] The heat of the coolant in the first circulation circuit is
transferred to the coolant in the second circulation circuit by the
heat transfer device, and the heat of the coolant in the second
circulation circuit is dissipated into the outside by the outdoor
heat exchanger, which can cool the battery and vehicle
compartment.
[0008] The cooling circuit is connected to the first circulation
circuit or second circulation circuit by use of the first to third
valves, so that the heat of the coolant in the cooling circuit can
be dissipated into the outside air by the outdoor heat exchanger in
the second circulation circuit, thereby cooling the motor generator
and inverter.
PRIOR ART DOCUMENT
Patent Document
[0009] PATENT DOCUMENT 1: JP 2011-121551A
SUMMARY OF INVENTION
[0010] The related art described above has an advantage that only
one outdoor heat exchanger is required to cool a plurality of
devices to be cooled, including the motor generator, the inverter,
the battery, and the vehicle compartment in a cooling system.
However, the entire circuit configuration might be complicated. In
this case, as the number of devices to be cooled increases, the
circuit configuration might become more complicated.
[0011] For example, the devices to be cooled, which require
cooling, include an EGR cooler, an intake air cooler, and the like,
in addition to the motor generator, the inverter, and the battery.
Those devices to be cooled have different required cooling
temperatures.
[0012] In order to appropriately cool the respective devices to be
cooled, the coolant to circulate through the respective devices is
proposed to be switchable among the devices, and thereby it leads
to an increase in the number of the circulation circuits according
to the number of devices to be cooled. Together with the increase,
the number of valves for connecting/disconnecting between the
cooling circuit and the respective circulation circuits is also
increased, resulting in a very complicated structure of flow paths
for connecting the respective circulation circuits and the cooling
circuit.
[0013] For this reason, in order to simplify the system structure,
a plurality of heat exchangers used for the cooling system is
proposed to be combined (integrated) together. The combined
(integrated) heat exchangers, however, have a plurality of inlets
and outlets for fluids to be heat-exchanged, resulting in less
flexibility in connection of pipes or arrangement of the heat
exchangers.
[0014] The present disclosure has been made in view of the
foregoing matters, and it is an object of the present disclosure to
provide a heat exchanger having high flexibility in connection of
pipes and arrangement of heat exchangers.
[0015] According to one aspect of the present disclosure, a heat
exchanger includes: (i) a heat exchanging portion configured by
stacking a plurality of refrigerant tubes through which a
refrigerant in a vapor-compression refrigeration cycle flows, and a
plurality of heat medium tubes through which a heat medium flows to
exchange heat with the refrigerant; and (ii) a tank portion
provided with at least one of a refrigerant tank space adapted to
collect or distribute the refrigerant with respect to the
refrigerant tubes, and a heat medium tank space adapted to collect
or distribute the heat medium with respect to the heat medium
tubes. In the heat exchanger, the heat exchanging portion and the
tank portion are formed by bonding plate members. The heat
exchanging portion includes a first heat exchanging portion in
which heat is exchanged between the heat medium and the refrigerant
on a high-pressure side of the vapor-compression refrigeration
cycle, and a second heat exchanging portion in which heat is
exchanged between the heat medium and the refrigerant on a
low-pressure side of the vapor-compression refrigeration cycle. The
tank portion is provided with a refrigerant inlet that allows the
refrigerant to flow into the refrigerant tank space, a refrigerant
outlet that allows the refrigerant to flow from the refrigerant
tank space, a heat medium inlet that allows the heat medium to flow
into the heat medium tank space, and a heat medium outlet that
allows the heat medium to flow from the heat medium tank space.
Furthermore, at least one of the refrigerant inlet, the refrigerant
outlet, the heat medium inlet, and the heat medium outlet is
disposed between both ends of the tank portion in a tube stacking
direction of the refrigerant tubes and the heat medium tubes.
[0016] Thus, at least one of the refrigerant inlet, the refrigerant
outlet, the heat medium inlet, and the heat medium outlet is
disposed between both the ends of the tank portion in the tube
stacking direction of the refrigerant tubes and the heat medium
tubes, and thereby it is possible to increase the flexibility in
connection of the pipes and arrangement of the heat exchangers as
compared to the case where all the refrigerant inlet, refrigerant
outlet, heat medium inlet, and heat medium outlet are disposed at
both ends of the tank portion.
BRIEF DESCRIPTION OF DRAWINGS
[0017] FIG. 1 is an entire configuration diagram of a vehicle
cooling system in a first reference example;
[0018] FIG. 2 is a diagram for explaining a first mode in the
vehicle cooling system of FIG. 1;
[0019] FIG. 3 is a diagram for explaining a second mode in the
vehicle cooling system of FIG. 1;
[0020] FIG. 4 is a diagram for explaining a third mode in the
vehicle cooling system of FIG. 1;
[0021] FIG. 5 is a perspective view showing a first switching valve
and a second switching valve in the first reference example;
[0022] FIG. 6 is an exploded perspective view of the first
switching valve of FIG. 5;
[0023] FIG. 7 is a cross-sectional view of the first switching
valve of FIG. 5;
[0024] FIG. 8 is a cross-sectional view of the first switching
valve of FIG. 5;
[0025] FIG. 9 is a cross-sectional view of the first switching
valve of FIG. 5;
[0026] FIG. 10 is a cross-sectional view of the first switching
valve of FIG. 5;
[0027] FIG. 11 is a cross-sectional view of the first switching
valve of FIG. 5;
[0028] FIG. 12 is a cross-sectional view showing a first state of
the first switching valve of FIG. 5;
[0029] FIG. 13 is a cross-sectional view showing a second state of
the first switching valve of FIG. 5;
[0030] FIG. 14 is a cross-sectional view showing a third state of
the first switching valve of FIG. 5;
[0031] FIG. 15 is a block diagram showing an electric controller of
the vehicle cooling system shown in FIG. 1;
[0032] FIG. 16 is an entire configuration diagram of a vehicle
cooling system according to a first embodiment of the
invention;
[0033] FIG. 17 is a diagram for explaining a first mode in the
vehicle cooling system of FIG. 16;
[0034] FIG. 18 is a diagram for explaining a second mode in the
vehicle cooling system of FIG. 16;
[0035] FIG. 19 is a diagram for explaining a third mode in the
vehicle cooling system of FIG. 16;
[0036] FIG. 20 is a diagram for explaining a fourth mode in the
vehicle cooling system of FIG. 16;
[0037] FIG. 21 is a diagram for explaining a fifth mode in the
vehicle cooling system of FIG. 16;
[0038] FIG. 22 is a perspective view showing a coolant cooler and a
condenser in the first embodiment;
[0039] FIG. 23 is a flowchart showing the flow of a control process
performed by a controller of the first embodiment;
[0040] FIG. 24 is an entire configuration diagram of a vehicle
cooling system according to a second embodiment of the
invention;
[0041] FIG. 25 is a diagram for explaining a first mode in the
vehicle cooling system of FIG. 24;
[0042] FIG. 26 is a diagram for explaining a second mode in the
vehicle cooling system of FIG. 24;
[0043] FIG. 27 is a diagram for explaining a third mode in the
vehicle cooling system of FIG. 24;
[0044] FIG. 28 is a perspective view showing a coolant cooler, a
condenser, and a supercooler in a second embodiment;
[0045] FIG. 29 is an entire configuration diagram of a vehicle
cooling system according to a third embodiment of the
invention;
[0046] FIG. 30 is a diagram for explaining a first mode in the
vehicle cooling system of FIG. 29;
[0047] FIG. 31 is a diagram for explaining a second mode in the
vehicle cooling system of FIG. 29;
[0048] FIG. 32 is a diagram for explaining a third mode in the
vehicle cooling system of FIG. 29;
[0049] FIG. 33 is an entire configuration diagram of a vehicle
cooling system according to a fourth embodiment of the
invention;
[0050] FIG. 34 is a diagram for explaining a first mode in the
vehicle cooling system of FIG. 33;
[0051] FIG. 35 is a diagram for explaining a second mode in the
vehicle cooling system of FIG. 34;
[0052] FIG. 36 is an entire configuration diagram of a vehicle
cooling system according to a fifth embodiment of the
invention;
[0053] FIG. 37 is a perspective view showing a coolant cooler, a
condenser, and a supercooler in a sixth embodiment;
[0054] FIG. 38 is a perspective view showing a coolant cooler, a
condenser, and an expansion valve in a seventh embodiment;
[0055] FIG. 39 is a diagram for explaining a first mode in a
vehicle cooling system in a second reference example;
[0056] FIG. 40 is a diagram for explaining a second mode in a
vehicle cooling system in the second reference example;
[0057] FIG. 41 is a diagram for explaining a third mode in a
vehicle cooling system in the second reference example;
[0058] FIG. 42 is a diagram for explaining a fourth mode in a
vehicle cooling system in the second reference example;
[0059] FIG. 43 is a block diagram showing an electric controller of
the vehicle cooling system shown in the second reference
example;
[0060] FIG. 44 is a flowchart showing the flow of a control process
performed by a controller of the second reference example;
[0061] FIG. 45 is an entire configuration diagram of a vehicle
cooling system according to a third reference example;
[0062] FIG. 46 is an entire configuration diagram of a vehicle
cooling system according to a fourth reference example;
[0063] FIG. 47 is a perspective view showing a coolant cooler and a
condenser in an eighth embodiment;
[0064] FIG. 48 is a perspective view of a cutout portion of parts
of the coolant cooler and condenser shown in FIG. 47;
[0065] FIG. 49 is a front view of the coolant cooler and condenser
shown in FIG. 47;
[0066] FIG. 50 is a side view of the coolant cooler and condenser
shown in FIG. 47;
[0067] FIG. 51 is a side view of a coolant cooler and a condenser
in a first modified example of the eighth embodiment;
[0068] FIG. 52 is a front view of a coolant cooler and a condenser
in a second modified example of the eighth embodiment;
[0069] FIG. 53 is a graph showing the performances of the coolant
cooler and condenser shown in FIG. 52;
[0070] FIG. 54 is a front view of a coolant cooler and a condenser
in a third modified example of the eighth embodiment;
[0071] FIG. 55 is a graph showing the performances of the coolant
cooler and condenser shown in FIG. 54;
[0072] FIG. 56 is a perspective view showing a coolant cooler and a
condenser in a ninth embodiment;
[0073] FIG. 57 is a perspective view of cutout parts of the coolant
cooler and condenser shown in FIG. 56;
[0074] FIG. 58 is a perspective view showing a coolant cooler and a
condenser in a tenth embodiment;
[0075] FIG. 59 is a perspective view of cutout parts of the coolant
cooler and condenser shown in FIG. 58;
[0076] FIG. 60 is a perspective view showing a coolant cooler and a
condenser in an eleventh embodiment;
[0077] FIG. 61 is a perspective view of cutout parts of the coolant
cooler and condenser shown in FIG. 60;
[0078] FIG. 62 is a perspective view showing a coolant cooler and a
condenser in a twelfth embodiment;
[0079] FIG. 63 is a perspective view showing a coolant cooler, a
condenser, and an auxiliary heat exchanger in a thirteenth
embodiment;
[0080] FIG. 64 is a perspective view of cutout parts of the coolant
cooler, condenser, and auxiliary heat exchanger shown in FIG.
63;
[0081] FIG. 65 is an exemplary perspective view of the coolant
cooler and condenser shown in FIG. 63;
[0082] FIG. 66 is a front view showing a coolant cooler, a
condenser, and an auxiliary heat exchanger in a fourteenth
embodiment;
[0083] FIG. 67 is a perspective view showing a part near a first
fluid outlet shown in FIG. 66;
[0084] FIG. 68 is a perspective view showing a part near a second
fluid outlet shown in FIG. 66;
[0085] FIG. 69 is a front view of a plate member forming a
condenser in a fifteenth embodiment;
[0086] FIG. 70 is a front view of a plate member forming a coolant
cooler in the fifteenth embodiment;
[0087] FIG. 71 is a cross-sectional view showing a part near an
expansion valve in the fifteenth embodiment;
[0088] FIG. 72 is an entire configuration diagram of a thermal
management system in another embodiment of the invention; and
[0089] FIG. 73 is an entire configuration diagram of a thermal
management system in another embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0090] In the following, preferred embodiments of the present
invention and reference examples will be described with reference
to the accompanying drawings. The same or equivalent parts in the
respective embodiments and reference examples below are indicated
by the same reference characters throughout the figures.
First Reference Example
[0091] A first reference example of the invention will be described
below based on FIGS. 1 to 15. The first reference example is as a
precondition for a first embodiment to be described later. A
vehicle cooling system 10 (vehicle thermal management system) shown
in FIG. 1 is used to cool various devices mounted on a vehicle
(devices requiring cooling or heating) or an interior of the
vehicle to an appropriate temperature.
[0092] In this reference example, the cooling system 10 is applied
to a hybrid car that can obtain the driving force for traveling
from both an internal combustion engine (engine) and an electric
motor for traveling.
[0093] The hybrid car of this reference example is configured as a
plug-in hybrid car that can charge a battery (vehicle-mounted
battery) mounted on the vehicle with power supplied from an
external power source (commercial power source) during stopping of
the vehicle. For example, a lithium ion battery can be used as the
battery.
[0094] A driving force output from an engine is used not only for
traveling of the vehicle, but also for operating a generator. Power
generated by the generator and power supplied from the external
power source can be stored in the battery. The power stored in the
battery can be supplied not only to the electric motor for
traveling, but also to various vehicle-mounted devices, such as
electric components included in the cooling system.
[0095] As shown in FIG. 1, the cooling system 10 includes a first
pump 11, a second pump 12, a radiator 13, a coolant cooler 14, a
battery cooler 15, an inverter cooler 16, an exhaust gas cooler 17,
a cooler core 18, a first switching valve 19, and a second
switching valve 20.
[0096] The first pump 11 and the second pump 12 are an electric
pump for sucking and discharging the coolant (heat medium). The
coolant is preferably liquid containing at least ethylene glycol or
dimethylpolysiloxane.
[0097] The radiator 13 is a heat exchanger for heat dissipation
(radiator) that dissipates heat of the coolant into the outside air
by exchanging heat between the coolant and the outside air. The
coolant outlet side of the radiator 13 is connected to the coolant
suction side of the first pump 11. An outdoor blower 21 is an
electric blower for blowing the outside air to the radiator 13. The
radiator 13 and the outdoor blower 21 are disposed at the forefront
of the vehicle. Thus, during traveling of the vehicle, the radiator
13 can face the traveling air.
[0098] The coolant cooler 14 is a cooling device for cooling the
coolant by exchanging heat between the coolant and a low-pressure
refrigerant of a refrigeration cycle 22. The coolant inlet side of
the coolant cooler 14 is connected to the coolant discharge side of
the second pump 12.
[0099] The coolant cooler 14 serves as an evaporator of the
refrigeration cycle 22. The refrigeration cycle 22 is an
evaporation compression refrigerator which includes a compressor
23, a condenser 24, an expansion valve 25, and the coolant cooler
14 as the evaporator. The refrigeration cycle 22 of this reference
example employs a fluorocarbon refrigerant as the refrigerant, and
forms a subcritical refrigeration cycle whose high-pressure side
refrigerant pressure does not exceed the critical pressure of the
refrigerant.
[0100] The compressor 23 is an electric compressor driven by power
supplied from the battery. The compressor 23 sucks and compresses
the refrigerant in the refrigeration cycle 22 to discharge the
compressed refrigerant therefrom. The condenser 24 is a
high-pressure side heat exchanger for condensing a high-pressure
refrigerant by exchanging heat between the outside air and the
high-pressure refrigerant discharged from the compressor 23.
[0101] The expansion valve 25 is a decompression device for
decompressing and expanding a liquid-phase refrigerant condensed by
the condenser 24. The coolant cooler 14 is a low-pressure side heat
exchanger for evaporating a low-pressure refrigerant by exchanging
heat between the coolant and the low-pressure refrigerant
decompressed and expanded by the expansion valve 25. The gas-phase
refrigerant evaporated at the coolant cooler 14 is sucked into and
compressed by the compressor 23.
[0102] The radiator 13 serves to cool the coolant by the outside
air, while the coolant cooler 14 serves to cool the coolant by the
low-pressure refrigerant of the refrigeration cycle 22. Thus, the
temperature of the coolant cooled by the coolant cooler 14 is lower
than that of the coolant cooled by the radiator 13.
[0103] Specifically, the radiator 13 cannot cool the coolant to a
temperature lower than that of the outside air, whereas the coolant
cooler 14 can cool the coolant to a temperature lower than that of
the outside air.
[0104] Hereinafter, the coolant cooled by the outside air in the
radiator 13 is referred to as an "intermediate-temperature
coolant", and the coolant cooled by the low-pressure refrigeration
of the refrigerant cycle 22 in the coolant cooler 14 is referred to
as a "low-temperature coolant".
[0105] Each of the coolant cooler 14, the battery cooler 15, the
inverter cooler 16, the exhaust gas cooler 17, and the cooler core
18 is the device to be cooled (device for temperature adjustment),
which is cooled (or whose temperature is adjusted) by either the
intermediate-temperature coolant or the low-temperature
coolant.
[0106] The battery cooler 15 has a flow passage for coolant, and
cools the battery by dissipating the heat of the battery into the
coolant. The battery preferably has its temperature maintained in a
range of about 10 to 40.degree. C. for the purpose of preventing
the reduction in output, a decrease in charging efficiency,
degradation, and the like.
[0107] The inverter cooler 16 has a flow passage for coolant, and
cools the inverter by dissipating the heat of the inverter into the
coolant. The inverter is a power converter that converts a
direct-current (DC) power supplied from the battery to an
alternating-current (AC) voltage to output the AC voltage to an
electric motor for traveling. The inverter preferably has its
temperature maintained at 65.degree. C. or lower for the purpose of
preventing the degradation thereof or the like.
[0108] The exhaust gas cooler 17 has a flow passage for coolant,
and cools exhaust gas by dissipating the heat of the exhaust gas of
the engine into the coolant. The exhaust gas cooled by the exhaust
gas cooler 17 is returned to the intake side of the engine. The
exhaust gas returned to the intake side of the engine preferably
has its temperature maintained in a range of 40 to 100.degree. C.
for the purpose of reducing the engine loss, and preventing
knocking and generation of NOX, and the like.
[0109] The cooler core 18 is a heat exchanger for cooling that
cools blast air by exchanging heat between the coolant and the
blast air. An indoor blower 26 is an electric blower for blowing
the outside air to the cooler core 18. The cooler core 18 and the
indoor blower 26 are disposed inside a casing 27 of the indoor air
conditioning unit.
[0110] Each of the first and second switching valves 19 and 20 is a
flow switching device that switches the flow of coolant. The first
switching valve 19 and the second switching valve have the same
basic structure. However, the first switching valve 19 differs from
the second switching valve 20 in that an inlet and outlet for the
coolant are reversed to each other.
[0111] The first switching valve 19 includes two inlets 19a and 19b
as an inlet for the coolant, and four outlets 19c, 19d, 19e, and
19f as an outlet for the coolant.
[0112] The inlet 19a is connected to the coolant discharge side of
the first pump 11. The inlet 19b is connected to the coolant outlet
side of the coolant cooler 14.
[0113] The outlet 19c is connected to the coolant inlet side of the
cooler core 18. The outlet 19d is connected to the coolant inlet
side of the exhaust gas cooler 17. The outlet 19e is connected to
the coolant inlet side of the battery cooler 15. The outlet 19f is
connected to the coolant inlet side of the inverter cooler 16.
[0114] The second switching valve 20 includes inlets 20a, 20b, 20c,
and 20d as an inlet for the coolant, and outlets 20e, and 20f as an
outlet for the coolant.
[0115] The inlet 20a is connected to the coolant outlet side of the
cooler core 18. The inlet 20b is connected to the coolant outlet
side of the exhaust gas cooler 17. The inlet 20c is connected to
the coolant outlet side of the battery cooler 15. The inlet 20d is
connected to the coolant outlet side of the inverter cooler 16.
[0116] The outlet 20e is connected to the coolant inlet side of the
radiator 13. The outlet 20f is connected to the coolant suction
side of the second pump 12.
[0117] The first switching valve 19 is configured to be capable of
switching among three types of communication states between the
inlets 19a and 19b, and the outlets 19c, 19d, 19e, and 19f. The
second switching valve 20 is also configured to be capable of
switching among three types of communication states between the
inlets 20a, 20b, 20c, and 20d, and the outlets 20e and 20f.
[0118] FIG. 2 shows the operation (first mode) of the cooling
system 10 when the first and second switching valves 19 and 20 are
switched to a first state.
[0119] In the first state, the first switching valve 19 connects
the inlet 19a with the outlets 19d, 19e, and 19f, and also connects
the inlet 19b with the outlet 19c. Thus, the first switching valve
19 allows the coolant entering the inlet 19a to flow out of the
outlets 19d, 19e, and 19f as indicated by alternate long and short
dashed arrows in FIG. 2, and also allows the coolant entering the
inlet 19b to flow out of the outlet 19c as indicated by a solid
arrow in FIG. 2.
[0120] In the first state, the second switching valve 20 connects
the inlets 20b, 20c, and 20d with the outlet 20e, and also connects
the inlet 20a with the outlet 20f. Thus, the second switching valve
20 allows the coolant entering the inlets 20b, 20c, and 20d to flow
out of the outlet 20e as indicated by alternate long and short
dashed arrows in FIG. 2, and also allows the coolant entering the
inlet 20a to flow out of the outlet 20f as a solid arrow in FIG.
2.
[0121] FIG. 3 shows the operation (second mode) of the cooling
system 10 when the first and second switching valves 19 and 20 are
switched to a second state.
[0122] In the second state, the first switching valve 19 connects
the inlet 19a with the outlets 19d, and 19f, and also connects the
inlet 19b with the outlets 19c and 19e. Thus, the first switching
valve 19 allows the coolant entering the inlet 19a to flow out of
the outlets 19d, and 19f as indicated by alternate long and short
dashed arrows in FIG. 3, and also allows the coolant entering the
inlet 19b to flow out of the outlets 19c and 19e as solid arrows in
FIG. 3.
[0123] In the second state, the second switching valve 20 connects
the inlets 20a and 20c with the outlet 20f, and also connects the
inlets 20b and 20d with the outlet 20e. Thus, the second switching
valve 20 allows the coolant entering the inlets 20b and 20d to flow
out of the outlet 20e as indicated by alternate long and short
dashed arrows in FIG. 3, and also allows the coolant entering the
inlets 20a and 20c to flow out of the outlet 20f as solid arrows in
FIG. 3.
[0124] FIG. 4 shows the operation (third mode) of the cooling
system 10 when the first and second switching valves 19 and 20 are
switched to a third state.
[0125] In the third state, the first switching valve 19 connects
the inlet 19a with the outlet 19d, and also connects the inlet 19b
with the outlets 19c, 19e, and 19f. Thus, the first switching valve
19 allows the coolant entering the inlet 19a to flow out of the
outlet 19d as indicated by an alternate long and short dashed arrow
in FIG. 4, and also allows the coolant entering the inlet 19b to
flow out of the outlets 19c, 19e, and 19f as solid arrows in FIG.
4.
[0126] In the third state, the second switching valve 20 connects
the inlet 20b with the outlet 20e and also connects the inlets 20a,
20c, and 20d with the outlet 20f. Thus, the second switching valve
20 allows the coolant entering the inlet 20b to flow out of the
outlet 20e as indicated by an alternate long and short dashed arrow
in FIG. 4, and also allows the coolant entering the inlets 20a,
20c, and 20d to flow out of the outlet 20f as indicated by a solid
arrow in FIG. 3.
[0127] As shown in FIG. 5, the first switching valve 19 and the
second switching valve 20 include rotary shafts 191 and 201 of
valve elements, respectively. A rotation force of an output shaft
30a of an electric motor 30 for a switching valve is transferred to
the rotary shafts 191 and 201 via gears 31, 32, 33, and 34. Thus,
by the common electric motor 30 for a switching valve, the valve
element of the first switching valve 19 and the valve element of
the second switching valve 20 are driven to cooperatively
rotate.
[0128] Alternatively, an electric motor for a switching valve may
be individually provided in each of the first and the second
switching valves 19 and 20. In such a case, the operations of the
two electric motors for the switching valves may be cooperatively
controlled, so that the valve elements of the first and second
switching valves 19 and 20 can be driven to cooperatively
rotate.
[0129] The first switching valve 19 and the second switching valve
20 have the same basic structure. In the following, the specific
structure of the first switching valve 19 will be described, and
thus the description of the specific structure of the second
switching valve 20 will be omitted.
[0130] The first switching valve 19 includes a case 192 serving as
an outer shell. The case 192 is formed in a substantially
cylindrical shape extending in the longitudinal direction of the
rotary shaft 191 of the valve element (in the vertical direction of
FIG. 5). The rotary shaft 191 of the valve element penetrates one
end surface (upper end surface shown in FIG. 5) of the case
192.
[0131] The cylindrical surface of the case 192 has outer and inner
diameters thereof decreased in four stages from one end side (upper
end side of FIG. 5) to the other end side (other end side of FIG.
5). Specifically, at the cylindrical surface of the case 192, a
first cylindrical portion 192a with the largest outer and inner
diameters, a second cylindrical portion 192b with the second
largest outer and inner diameters, a third cylindrical portion 192c
with the third largest outer and inner diameters, and a fourth
cylindrical portion 192d with the smallest outer and inner
diameters are formed in that order from the one end side to the
other end side.
[0132] The first cylindrical portion 192a is provided with the
outlet 19c. The second cylindrical portion 192b is provided with
the outlet 19d. The third cylindrical portion 192c is provided with
the outlet 19e. The fourth cylindrical portion 192d is provided
with the outlet 19f.
[0133] As shown in FIG. 6, at the other end surface of the case 192
(lower end surface shown in FIG. 6), the inlet 19a for coolant and
the inlet 19b for coolant are formed.
[0134] An inner cylindrical member 193 is inserted into an internal
space of the case 192. The inner cylindrical member 193 is formed
in a cylindrical shape with constant inner and outer diameters, and
positioned coaxially with respect to the case 192. One end of the
inner cylindrical member 193 on the other end side of the case 192
(the lower end thereof shown in FIG. 6) is fixed in intimate
contact with the other end surface of the case 192.
[0135] A partition plate 193a is provided within the inner
cylindrical member 193. The partition plate 193a is formed across
the entire area of the inner cylindrical member 193 in the axial
direction thereof to partition the internal space of the inner
cylindrical member 193 into two half-round spaces 193b and
193c.
[0136] The first space 193b of the two spaces 193b and 193c
communicates with the inlet 19a of the case 192, and the second
space 193c thereof communicates with the inlet 19b of the case
192.
[0137] The cylindrical surface of the inner member 193 is provided
with four openings 193d, 193e, 193f, and 193g communicating with
the first space 193b, and four openings 193h, 193i, 193j, and 193k
communicating with the second space 193c.
[0138] With the inner cylindrical member 193 inserted into the case
192, the openings 193d and 193h of the inner cylindrical member 193
are opposed to the first cylindrical portion 192a of the
cylindrical member 193, the openings 193e and 193i are opposed to
the second cylindrical portion 192b of the inner cylindrical member
193, the openings 193f and 193j are opposed to the third
cylindrical portion 192c of the inner cylindrical member 193, and
the openings 193g and 193k are opposed to the fourth cylindrical
portion 192d of the inner cylindrical member 193.
[0139] A valve element 194 for opening and closing eight openings
193d to 193k of the inner cylindrical member 193 is inserted into
between the case 192 and the inner cylindrical member 193. The
valve element 194 is formed in a substantially cylindrical shape,
and positioned coaxially with respect to the case 192 and the inner
cylindrical member 193.
[0140] A rotary shaft 191 is fixed to the center of one end surface
(upper end surface of FIG. 6) of the valve element 194. The valve
element 194 is rotatable with the rotary shaft 191 centered with
respect to the case 192 and the inner cylindrical member 193.
[0141] The inner diameter of the valve element 194 is set constant,
like the outer diameter of the inner cylindrical member 193. Like
the inner diameter of the case 192, the outer diameter of the valve
element 194 is decreased in four stages from one end side to the
other end side thereof.
[0142] Specifically, at the outer peripheral surface of the valve
element 194, a first cylindrical portion 194a with the largest
outer diameter, a second cylindrical portion 194b with the second
largest outer diameter, a third cylindrical portion 194c with the
third largest outer diameter, and a fourth cylindrical portion 194d
with the smallest outer diameter are formed in that order from the
one end side to the other end side.
[0143] With the valve element 194 inserted into between the case
192 and the inner cylindrical member 193, the first cylindrical
portion 194a of the valve element 194 is opposed to the first
cylindrical portion 192a of the case 192, the second cylindrical
portion 194b of the valve element 194 is opposed to the second
cylindrical portion 192b of the case 192, the third cylindrical
portion 194c of the valve element 194 is opposed to the third
cylindrical portion 194c of the case 192, and the fourth
cylindrical portion 194d of the valve element 194 is opposed to the
fourth cylindrical portion 194d of the case 192.
[0144] A plurality of holes 194e is formed at the first cylindrical
portion 194a of the valve element 194. A plurality of holes 194f is
formed at the second cylindrical portion 194b of the valve element
194. A plurality of holes 194g is formed at the third cylindrical
portion 194c of the valve element 194. A plurality of holes 194h is
formed at the fourth cylindrical portion 194d of the valve element
194.
[0145] FIG. 7 is a cross-sectional view of the first switching
valve 19 taken at a part of the first cylindrical portion 194a of
the valve element 194 in the direction perpendicular to the axial
direction thereof.
[0146] The three holes 194e of the first cylindrical portion 194a
of the valve element 194 are formed in the circumferential
direction of the first cylindrical portion 194a. When the valve
element 194 is located in a predetermined rotating position, the
holes 194e are superimposed over the openings 193d and 193h of the
inner cylindrical member 193.
[0147] A packing 195 is fixed to the periphery of each of the
openings 193d and 193h of the inner cylindrical member 193. The
packing 195 is in intimate contact with the first cylindrical
portion 194a of the valve element 194, and serves to seal a gap
between the first cylindrical portion 194a and the openings 193d
and 193h of the inner cylindrical member 193 in a liquid-tight
manner.
[0148] A first ring-like space 196a is formed between the first
cylindrical portion 194a of the valve element 194 and the first
cylindrical portion 192a of the case 192. The first ring-like space
196a communicates with the outlet 19c.
[0149] FIG. 8 is a cross-sectional view of the first switching
valve 19 taken at a part of the second cylindrical portion 194b of
the valve element 194 in the direction perpendicular to the axial
direction thereof.
[0150] The three holes 194f of the second cylindrical portion 194b
of the valve element 194 are formed in the circumferential
direction of the second cylindrical portion 194b. When the valve
element 194 is located in a predetermined rotating position, the
holes 194f are superimposed over the openings 193e and 193i of the
inner cylindrical member 193.
[0151] The packing 195 is fixed to the periphery of each of the
openings 193e and 193i of the inner cylindrical member 193. The
packing 195 is in intimate contact with the second cylindrical
portion 194b of the valve element 194, and serves to seal a gap
between the second cylindrical portion 194b and the openings 193e
and 193i of the inner cylindrical member 193 in a liquid-tight
manner.
[0152] A second ring-like space 196b is formed between the second
cylindrical portion 194b of the valve element 194 and the second
cylindrical portion 192b of the case 192. The second ring-like
space 196b communicates with the outlet 19d.
[0153] FIG. 9 is a cross-sectional view of the first switching
valve 19 taken at a part of the third cylindrical portion 194c of
the valve element 194 in the direction perpendicular to the axial
direction thereof.
[0154] The three holes 194g of the third cylindrical portion 194c
of the valve element 194 are formed in the circumferential
direction of the third cylindrical portion 194c. When the valve
element 194 is located in a predetermined rotating position, the
holes 194g are superimposed over the openings 193f and 193j of the
inner cylindrical member 193.
[0155] The packing 195 is fixed to the periphery of each of the
openings 193f and 193j of the inner cylindrical member 193. The
packing 195 is in intimate contact with the third cylindrical
portion 194c of the valve element 194, and serves to seal a gap
between the third cylindrical portion 194c and the openings 193f
and 193j of the inner cylindrical member 193 in a liquid-tight
manner.
[0156] A third ring-like space 196c is formed between the third
cylindrical portion 194c of the valve element 194 and the third
cylindrical portion 192c of the case 192. The third ring-like space
196c communicates with the outlet 19e.
[0157] FIG. 10 is a cross-sectional view of the first switching
valve 19 taken at a part of the fourth cylindrical portion 194d of
the valve element 194 in the direction perpendicular to the axial
direction thereof.
[0158] The three holes 194h of the fourth cylindrical portion 194d
of the valve element 194 are formed in the circumferential
direction of the third cylindrical portion 194c. When the valve
element 194 is located in a predetermined rotating position, the
holes 194h are superimposed over the openings 193g and 193k of the
inner cylindrical member 193.
[0159] The packing 195 is fixed to the periphery of each of the
openings 193g and 193k of the inner cylindrical member 193. The
packing 195 is in intimate contact with the fourth cylindrical
portion 194d of the valve element 194, and serves to seal a gap
between the fourth cylindrical portion 194d and the openings 193g
and 193k of the inner cylindrical member 193 in a liquid-tight
manner.
[0160] A fourth ring-like space 196d is formed between the fourth
cylindrical portion 194d of the valve element 194 and the fourth
cylindrical portion 192d of the case 192. The fourth ring-like
space 196d communicates with the outlet 19f.
[0161] As shown in FIG. 11, a gap between the first ring-like space
196a and the second ring-like space 196b is sealed by a packing 197
in a liquid-tight manner. The packing 197 is formed in a ring-like
shape so as to have its entire periphery sandwiched between a
stepped surface of the valve element 194 and a stepped surface of
the case 192.
[0162] Although not shown, a gap between the second and third
ring-like spaces 196b and 196c, as well as a gap between the third
and fourth ring-like spaces 196c and 196d are also sealed by the
ring-like packing 197 in the liquid-tight manner.
[0163] The first state of the first switching valve 19 will be
described below based on FIG. 12. FIG. 12 is a cross-sectional view
of the first switching valve 19 taken at a part of the first
cylindrical portion 194a of the valve element 194 in the direction
perpendicular to the axial direction thereof. For better
understanding of the description, FIG. 12 illustrates only one of
three holes of each of the types 194e, 194f, 194g, and 194h while
omitting the illustration of other remaining two holes 194e, 194f,
194g, and 194h of each type.
[0164] In the first state, the valve element 194 is rotated to the
position shown in FIG. 12, so that the hole 194e of the first
cylindrical portion 194a of the valve element 194 is superimposed
over the opening 193h on the second space 193c side of the inner
cylindrical member 193, thereby causing the first cylindrical
portion 194a of the valve element 194 to close the opening 193d on
the first space 193b side of the inner cylindrical member 193.
[0165] Thus, as indicated by the solid arrows in FIG. 12, the
second space 193c of the inner cylindrical member 193 communicates
with the outlet 19c via the opening 193h of the inner cylindrical
member 193, the hole 194e of the valve element 194, and the first
ring-like space 196a. On the other hand, the first space 193b of
the inner cylindrical member 193 does not communicate with the
outlet 19c.
[0166] Accordingly, in the first state, the outlet 19c communicates
with the inlet 19b, and not with the inlet 19a.
[0167] Although not shown, in the first state, the hole 194f of the
second cylindrical portion 194b of the valve element 194 is
superimposed over the opening 193e on the first space 193b side of
the inner cylindrical member 193, thereby causing the second
cylindrical portion 194b of the valve element 194 to close the
opening 193i on the second space 193c side of the inner cylindrical
member 193.
[0168] Thus, as indicated by a dashed arrow in FIG. 12, the first
space 193b of the inner cylindrical member 193 communicates with
the outlet 19d, and the second space 193c of the inner cylindrical
member 193 does not communicate with the outlet 19d. Accordingly,
the outlet 19d communicates with the inlet 19a, and not with the
inlet 19b.
[0169] Although not shown, in the first state, the hole 194g of the
third cylindrical portion 194c of the valve element 194 is
superimposed over the opening 193f on the first space 193b side of
the inner cylindrical member 193, thereby causing the third
cylindrical portion 194c of the valve element 194 to close the
opening 193j on the second space 193c side of the inner cylindrical
member 193.
[0170] Thus, as indicated by a dashed arrow in FIG. 12, the first
space 193b of the inner cylindrical member 193 communicates with
the outlet 19e, and the second space 193c of the inner cylindrical
member 193 does not communicate with the outlet 19e. Accordingly,
the outlet 19e communicates with the inlet 19a, and not with the
inlet 19b.
[0171] Although not shown, in the first state, the hole 194h of the
fourth cylindrical portion 194d of the valve element 194 is
superimposed over the opening 193g on the first space 193b side of
the inner cylindrical member 193, thereby causing the fourth
cylindrical portion 194d of the valve element 194 to close the
opening 193k on the second space 193c side of the inner cylindrical
member 193.
[0172] Thus, as indicated by the dashed arrow of FIG. 12, the first
space 193b of the inner cylindrical member 193 communicates with
the outlet 19f, and the second space 193c of the inner cylindrical
member 193 does not communicate with the outlet 19f. Accordingly,
the outlet 19f communicates with the inlet 19a, and not with the
inlet 19b.
[0173] The second state of the first switching valve 19 will be
described below based on FIG. 13. FIG. 13 is a cross-sectional view
of the first switching valve 19 taken at a part of the first
cylindrical portion 194a of the valve element 194 in the direction
perpendicular to the axial direction thereof. For better
understanding of the description, FIG. 13 illustrates only one of
three holes of each of the types 194e, 194f, 194g, and 194h while
omitting the illustration of other remaining two holes 194e, 194f,
194g, and 194h of each type.
[0174] In the second state, the valve element 194 is rotated to the
position shown in FIG. 13, so that the hole 194e of the first
cylindrical portion 194a of the valve element 194 is superimposed
over the opening 193h on the second space 193c side of the inner
cylindrical member 193, thereby causing the first cylindrical
portion 194a of the valve element 194 to close the opening 193d on
the first space 193b side of the inner cylindrical member 193.
[0175] Thus, as indicated by a solid arrow in FIG. 13, the second
space 193c of the inner cylindrical member 193 communicates with
the outlet 19c, and the first space 193b of the inner cylindrical
member 193 does not communicate with the outlet 19c. Accordingly,
the outlet 19c communicates with the inlet 19b, and not with the
inlet 19a.
[0176] Although not shown, in the second state, the hole 194f of
the second cylindrical portion 194b of the valve element 194 is
superimposed over the opening 193e on the first space 193b side of
the inner cylindrical member 193, thereby causing the second
cylindrical portion 194b of the valve element 194 to close the
opening 193i on the second space 193c side of the inner cylindrical
member 193.
[0177] Thus, as indicated by a dashed arrow in FIG. 13, the first
space 193b of the inner cylindrical member 193 communicates with
the outlet 19d, and the second space 193c of the inner cylindrical
member 193 does not communicate with the outlet 19d. Accordingly,
the outlet 19d communicates with the inlet 19a, and not with the
inlet 19b.
[0178] Although not shown, in the second state, the hole 194g of
the third cylindrical portion 194c of the valve element 194 is
superimposed over the opening 193j on the second space 193c side of
the inner cylindrical member 193, thereby causing the third
cylindrical portion 194c of the valve element 194 to close the
opening 193f on the first space 193b side of the inner cylindrical
member 193.
[0179] Thus, as indicated by a dashed arrow in FIG. 13, the second
space 193c of the inner cylindrical member 193 communicates with
the outlet 19e, and the first space 193b of the inner cylindrical
member 193 does not communicate with the outlet 19e. Accordingly,
the outlet 19e communicates with the inlet 19b, and not with the
inlet 19a.
[0180] Although not shown, in the second state, the hole 194h of
the fourth cylindrical portion 194d of the valve element 194 is
superimposed over the opening 193g on the first space 193b side of
the inner cylindrical member 193, thereby causing the fourth
cylindrical portion 194d of the valve element 194 to close the
opening 193k on the second space 193c side of the inner cylindrical
member 193.
[0181] Thus, as indicated by the dashed arrow of FIG. 13, the first
space 193b of the inner cylindrical member 193 communicates with
the outlet 19f, and the second space 193c of the inner cylindrical
member 193 does not communicate with the outlet 19f. Accordingly,
the outlet 19f communicates with the inlet 19a, and not with the
inlet 19b.
[0182] The third state of the first switching valve 19 will be
described below based on FIG. 14. FIG. 14 is a cross-sectional view
of the first switching valve 19 taken at a part of the first
cylindrical portion 194a of the valve element 194 in the direction
perpendicular to the axial direction thereof. For better
understanding of the description, FIG. 14 illustrates only one of
three holes of each of the types 194e, 194f, 194g, and 194h while
omitting the illustration of other remaining two holes 194e, 194f,
194g, and 194h of each type.
[0183] In the third state, the valve element 194 is rotated to the
position shown in FIG. 14, so that the hole 194e of the first
cylindrical portion 194a of the valve element 194 is superimposed
over the opening 193h on the second space 193c side of the inner
cylindrical member 193, thereby causing the first cylindrical
portion 194a of the valve element 194 to close the opening 193d on
the first space 193b side of the inner cylindrical member 193.
[0184] Thus, as indicated by a solid arrow in FIG. 14, the second
space 193c of the inner cylindrical member 193 communicates with
the outlet 19c, and the first space 193b of the inner cylindrical
member 193 does not communicate with the outlet 19c. Accordingly,
the outlet 19c communicates with the inlet 19b, and not with the
inlet 19a.
[0185] Although not shown, in the third state, the hole 194f of the
second cylindrical portion 194b of the valve element 194 is
superimposed over the opening 193e on the first space 193b side of
the inner cylindrical member 193, thereby causing the second
cylindrical portion 194b of the valve element 194 to close the
opening 193i on the second space 193c side of the inner cylindrical
member 193.
[0186] Thus, as indicated by a dashed arrow in FIG. 14, the first
space 193b of the inner cylindrical member 193 communicates with
the outlet 19d, and the second space 193c of the inner cylindrical
member 193 does not communicate with the outlet 19d. Accordingly,
the outlet 19d communicates with the inlet 19a, and not with the
inlet 19b.
[0187] Although not shown, in the third state, the hole 194g of the
third cylindrical portion 194c of the valve element 194 is
superimposed over the opening 193j on the second space 193c side of
the inner cylindrical member 193, thereby causing the third
cylindrical portion 194c of the valve element 194 to close the
opening 193f on the first space 193b side of the inner cylindrical
member 193.
[0188] Thus, as indicated by a dashed arrow in FIG. 14, the second
space 193c of the inner cylindrical member 193 communicates with
the outlet 19e, and the first space 193b of the inner cylindrical
member 193 does not communicate with the outlet 19e. Accordingly,
the outlet 19e communicates with the inlet 19b, and not with the
inlet 19a.
[0189] Although not shown, in the third state, the hole 194h of the
fourth cylindrical portion 194d of the valve element 194 is
superimposed over the opening 193k on the second space 193c side of
the inner cylindrical member 193, thereby causing the fourth
cylindrical portion 194d of the valve element 194 to close the
opening 193g on the first space 193b side of the inner cylindrical
member 193.
[0190] Thus, as indicated by a dashed arrow in FIG. 14, the second
space 193c of the inner cylindrical member 193 communicates with
the outlet 19f, and the first space 193b of the inner cylindrical
member 193 does not communicate with the outlet 19f. Accordingly,
the outlet 19f communicates with the inlet 19b, and not with the
inlet 19a.
[0191] Next, an electric controller of the cooling system 10 will
be described with reference to FIG. 15. A controller 40 is
comprised of a known microcomputer, including CPU, ROM, RAM, and
the like, and a peripheral circuit thereof. The controller 40 is a
control device for controlling the operations of the devices
connected to the output side, including the first pump 11, the
second pump 12, the compressor 23, the electric motor 30 for a
switching valve, and the like by performing various kinds of
computations and processing based on air conditioning control
programs stored in the ROM.
[0192] The controller 40 is integrally structured with a control
unit for controlling various devices for control connected to an
output side of the controller. The control unit for controlling the
operation of each of the devices for control includes a structure
(hardware and software) that is adapted to control the operation of
each of the devices for control.
[0193] In this reference example, particularly, the structure
(hardware and software) that controls the operation of the electric
motor 30 for a switching valve acts as a switching valve controller
40a. Obviously, the switching valve controller 40a may be
independently provided from the controller 40.
[0194] Detection signals from a group of sensors, including an
inside air sensor 41, an outside air sensor 42, a water temperature
sensor 43, and the like are input to the input side of the
controller 40.
[0195] The inside air sensor 41 is a detector (inside air
temperature detector) for detecting the temperature of inside air
(temperature of the vehicle interior). The outside air sensor 42 is
a detector (outside air temperature detector) for detecting the
temperature of outside air. The water temperature sensor 43 is a
detector (heat medium temperature detector) for detecting the
temperature of coolant flowing therethrough directly after passing
through the radiator 13.
[0196] An operation signal is input from an air conditioning switch
44 to the input side of the controller 40. The air conditioning
switch 44 is a switch for switching an air conditioner between ON
and OFF (in short, ON and OFF of cooling), and disposed near a dash
board in the vehicle compartment.
[0197] Now, the operation of the above-mentioned structure will be
described. When an outside air temperature detected by the outside
air sensor 42 is equal to or lower than 15.degree. C., the
controller 40 performs the first mode shown in FIG. 2. When an
outside air temperature detected by the outside air sensor 42
ranges from more than 15.degree. C. and to less than 40.degree. C.,
the controller 40 performs the second mode shown in FIG. 3. When an
outside air temperature detected by the outside air sensor 42 is
equal to or higher than 40.degree. C., the controller 40 performs
the third mode shown in FIG. 4.
[0198] In the first mode, the controller 40 controls the electric
motor 30 for a switching valve such that the first and second
switching valves 19 and 20 are brought into the first state shown
in FIG. 2 to thereby operate the first and second pumps 11 and 12
and the compressor 23.
[0199] Thus, the first switching valve 19 connects the inlet 19a
with the outlets 19d, 19e, and 19f, and also connects the inlet 19b
with the outlet 19c. The second switching valve 20 connects the
inlets 20b, 20c, and 20d with the outlet 20e, and also connects the
inlet 20a with the outlet 20f.
[0200] Accordingly, a first coolant circuit
(intermediate-temperature coolant circuit) is formed of the first
pump 11, the battery cooler 15, the inverter cooler 16, the exhaust
gas cooler 17, and the radiator 13, whereas a second coolant
circuit (low-temperature coolant circuit) is formed of the second
pump 12, the coolant cooler 14, and the cooler core 18.
[0201] That is, as indicated by alternate long and short dashed
arrows in FIG. 2, the coolant discharged from the first pump 11 is
branched by the first switching valve 19 into the battery cooler
15, the inverter cooler 16, and the exhaust gas cooler 17. Then,
the coolant flows in parallel through the battery cooler 15, the
inverter cooler 16, and the exhaust gas cooler 17 are collected
into the second switching valve 20 to flow through the radiator 13,
thereby being sucked into the first pump 11.
[0202] On the other hand, as indicated by a solid arrow in FIG. 2,
the coolant discharged from the second pump 12 flows through the
coolant cooler 14 and then through the cooler core 18 via the first
switching valve 19 into the second switching valve 20. The coolant
flows through the second switching valve 20, thereby being sucked
into the second pump 12.
[0203] In this way, in the first mode, the intermediate-temperature
coolant cooled by the radiator 13 flows through the battery cooler
15, the inverter cooler 16, and the exhaust gas cooler 17, whereas
the low-temperature coolant cooled by the coolant cooler 14 flows
through the cooler core 18.
[0204] As a result, the battery, the inverter, and the exhaust gas
are cooled by the intermediate-temperature coolant, and the blast
air into the vehicle interior is cooled by the low-temperature
coolant.
[0205] For example, when the outside air temperature is about
15.degree. C., the intermediate coolant cooled by the outside air
in the radiator 13 becomes at a temperature of about 25.degree. C.,
so that the intermediate-temperature coolant can sufficiently cool
the battery, inverter, and exhaust gas.
[0206] The low-temperature coolant cooled by the low-pressure
refrigerant of the refrigeration cycle 22 in the coolant cooler 14
becomes at about 0.degree. C., so that the low-temperature coolant
can sufficiently cool the blast air into the vehicle interior.
[0207] In the first mode, the battery, inverter, and exhaust gas
are cooled by the outside air, which can effectively achieve the
energy saving as compared to the case in which the battery,
inverter, and exhaust gas are cooled by the low-pressure
refrigerant of the refrigeration cycle 22.
[0208] In the second mode, the controller 40 controls the electric
motor 30 for a switching valve such that the first and second
switching valves 19 and 20 are brought into the second state shown
in FIG. 3 to thereby operate the first and second pumps 11 and 12
and the compressor 23.
[0209] Thus, the first switching valve 19 connects the inlet 19a
with the outlets 19d and 19f, and also connects the inlet 19b with
the outlets 19c and 19e. The second switching valve 20 connects the
inlets 20b and 20d with the outlet 20e, and also connects the
inlets 20a and 20c with the outlet 20f.
[0210] Accordingly, the first coolant circuit
(intermediate-temperature coolant circuit) is formed of the first
pump 11, the inverter cooler 16, the exhaust gas cooler 17, and the
radiator 13, whereas the second coolant circuit (low-temperature
coolant circuit) is formed of the second pump 12, the coolant
cooler 14, the cooler core 18, and the battery cooler 15.
[0211] That is, as indicated by alternate long and short dashed
arrows of FIG. 3, the coolant discharged from the first pump 11 is
branched by the first switching valve 19 into the inverter cooler
16 and the exhaust gas cooler 17. Then, the coolants flowing in
parallel through the inverter cooler 16 and the exhaust gas cooler
17 are collected into the second switching valve 20 to flow through
the radiator 13, thereby being sucked into the first pump 11.
[0212] On the other hand, as indicated by solid arrows of FIG. 3,
the coolant discharged from the second pump 12 flows through the
coolant cooler 14, and is branched by the first switching valve 19
into the cooler core 18 and the battery cooler 15. Then, the
coolants flowing in parallel through the cooler core 18 and the
battery cooler 15 are collected into the second switching valve 20
to be sucked into the second pump 12.
[0213] That is, in the second mode, the intermediate-temperature
coolant cooled by the radiator 13 flows through the inverter cooler
16 and the exhaust gas cooler 17, whereas the low-temperature
coolant cooled by the coolant cooler 14 flows through the cooler
core 18 and the battery cooler 15.
[0214] As a result, the inverter and the exhaust gas are cooled by
the intermediate-temperature coolant, and the battery and the blast
air into the vehicle interior are cooled by the low-temperature
coolant.
[0215] For example, when the outside air temperature is about
25.degree. C., the intermediate coolant cooled by the outside air
in the radiator 13 becomes at a temperature of about 40.degree. C.,
so that the intermediate-temperature coolant can sufficiently cool
the inverter, and exhaust gas.
[0216] The low-temperature coolant cooled by the low-pressure
refrigerant of the refrigeration cycle 22 in the coolant cooler 14
becomes at about 0.degree. C., so that the battery and the blast
air into the vehicle interior can be sufficiently cooled by the
low-temperature coolant.
[0217] Since in the second mode the battery is cooled by the
low-pressure refrigerant of the refrigeration cycle 22, the battery
can be sufficiently cooled even when the outside air cannot cool
the battery adequately because of the high temperature of the
outside air.
[0218] In the third mode, the controller 40 controls the electric
motor 30 for a switching valve such that the first and second
switching valves 19 and 20 are brought into the third state shown
in FIG. 4 to thereby operate the first and second pumps 11 and 12
and the compressor 23.
[0219] Thus, the first switching valve 19 connects the inlet 19a
with the outlet 19d and also connects the inlet 19b with the
outlets 19c, 19e, and 19f. The second switching valve 20 connects
the inlet 20b with the outlet 20e, and also connects the inlets
20a, 20c, and 20d with the outlet 20f.
[0220] Accordingly, the first coolant circuit
(intermediate-temperature coolant circuit) is formed of the first
pump 11, the exhaust gas cooler 17, and the radiator 13, whereas
the second coolant circuit (low-temperature coolant circuit) is
formed of the second pump 12, the coolant cooler 14, the cooler
core 18, the battery cooler 15, and the inverter cooler 16.
[0221] That is, as indicated by an alternate long and short dashed
arrow in FIG. 4, the coolant discharged from the first pump 11
flows through the exhaust gas cooler 17 via the first switching
valve 19, and then through the radiator 13 via the second switching
valve 20, thereby being sucked into the first pump 11.
[0222] On the other hand, as indicated by solid arrows in FIG. 4,
the coolant discharged from the second pump 12 flows through the
coolant cooler 14, and is branched by the first switching valve 19
into the cooler core 18, the battery cooler 15, and the inverter
cooler 16. Then, the coolants flowing in parallel through the
cooler core 18, the battery cooler 15, and the inverter cooler 16
are collected into the second switching valve 20 to be sucked into
the second pump 12.
[0223] Thus, in the third mode, the intermediate-temperature
coolant cooled by the radiator 13 flows through the exhaust gas
cooler 17, whereas the low-temperature coolant cooled by the
coolant cooler 14 flows through the cooler core 18, the battery
cooler 15, and the inverter cooler 16.
[0224] Thus, the exhaust gas is cooled by the coolant cooled by the
radiator 13, and the blast air into the vehicle interior, the
battery, and the inverter are cooled by the coolant cooled by the
coolant cooler 14.
[0225] For example, when the outside air temperature is about
40.degree. C., the intermediate-temperature coolant cooled by the
outside air in the radiator 13 becomes at a temperature of about
50.degree. C., so that the intermediate-temperature coolant can
sufficiently cool the exhaust gas.
[0226] The low-temperature coolant cooled by the low-pressure
refrigerant of the refrigeration cycle 22 in the coolant cooler 14
becomes at about 0.degree. C., so that the blast air into the
vehicle interior, the battery, and the inverter can be sufficiently
cooled by the low-temperature coolant.
[0227] Since in the third mode the battery and the inverter are
cooled by the low-pressure refrigerant of the refrigeration cycle
22, the battery and the inverter can be sufficiently cooled even
when the outside air cannot cool the battery and the inverter
adequately because of the very high temperature of the outside
air.
[0228] This reference example employs the simple structure in which
the devices 15, 16, 17, and 18 to be cooled are connected in
parallel between the first and second switching valves 19 and 20 to
thereby switch the coolants circulating through the respective
devices 15, 16, 17, and 18 to be cooled among the devices.
[0229] Specifically, the outside air temperature is detected as a
temperature associated with the temperature of the coolant obtained
after the heat exchange by the radiator 13, and then based on the
outside air temperature detected, the operations of the first
switching valve 19 and the second switching valve 20 are controlled
to thereby perform the first to third modes. Thus, the coolant
circulating through each of the devices 15, 16, 17, and 18 to be
cooled can be switched among the devices according to the
temperature of the coolant obtained after the heat exchange by the
radiator 13.
[0230] More specifically, when the outside air temperature is lower
than a predetermined temperature (15.degree. C. in this
embodiment), the first mode is performed to allow the coolant to
circulate between the first pump 11 and each of the devices 15, 16,
17, and 18 to be cooled. When the outside air temperature is higher
than the predetermined temperature (15.degree. C. in this
embodiment), the operation is shifted from the second mode to the
third mode as the outside air temperature becomes higher, which
increases the number of devices to be cooled for allowing the
coolant to circulate through the second pump 12.
[0231] Thus, the cooling load of the coolant cooler 14 (that is,
cooling load of the refrigeration cycle 22) can be changed
according to the temperature of the coolant obtained after the heat
exchange by the radiator 13, which can achieve the energy
saving.
[0232] More specifically, the devices 15, 16, 17, and 18 to be
cooled have different required cooling temperatures. When the
outside air temperature is higher than the predetermined
temperature (15.degree. C. in this embodiment), as the outside air
temperature becomes higher, the operation is shifted from the
second mode to the third mode, whereby the coolant circulates
starting from the device requiring the lower cooling temperature
through the other devices in the order of increasing the required
cooling temperature with respect to the second pump 12.
[0233] In this way, this embodiment can shift the circulation
through the respective devices to be cooled 15, 16, 17, and 18
between the low-temperature coolant and the high-temperature
coolant in accordance with the required coolant temperature
thereof, thereby appropriately cooling the devices 15, 16, 17, and
18 to be cooled, while achieving the energy saving.
First Embodiment
[0234] Although in the first reference example, the exhaust gas
cooler 17 is connected between the outlet 19d of the first
switching valve 19 and the inlet 20b of the second switching valve
20, in a first embodiment, as shown in FIG. 16, a condenser 50
(device to be cooled) and a heater core 51 are connected between
the outlet 19d of the first switching valve 19 and the inlet 20b of
the second switching valve 20.
[0235] The condenser 50 is a high-pressure side heat exchanger for
condensing a high-pressure refrigerant by exchanging heat between
the coolant and the high-pressure refrigerant discharged from the
compressor 23, thereby heating the coolant. The coolant inlet side
of the condenser 50 is connected to the outlet 19d of the first
switching valve 19.
[0236] The heater core 51 is a heat exchanger for heating that
heats the blast air by exchanging heat between the coolant and the
blast air having passed through the cooler core 18. The heater core
51 is disposed on the downstream side of the air flow of the cooler
core 18 within the casing 27 of the indoor air conditioning
unit.
[0237] The coolant inlet side of the heater core 51 is connected to
the coolant outlet side of the condenser 50. The coolant outlet
side of the heater core 51 is connected to the inlet 20b of the
second switching valve 20.
[0238] Although in the first reference example, the coolant cooler
14 is connected between the discharge side of the first pump 11 and
the inlet 19b of the first switching valve 19, in this embodiment,
the coolant cooler 14 is connected between the first switching
valve 19 and the cooler core 18. Specifically, the coolant inlet
side of the coolant cooler 14 is connected to the outlet 19c of the
first switching valve 19, and the coolant outlet side of the
coolant cooler 14 is connected to the coolant inlet side of the
cooler core 18.
[0239] The first switching valve 19 is configured to be capable of
switching among the five types of communication states between the
inlets 19a and 19b and the outlets 19c, 19d, 19e, and 19f. The
second switching valve 20 is also configured to be capable of
switching among five types of communication states between the
inlets 20a, 20c, and 20d and the outlets 20e, and 20f.
[0240] FIG. 17 shows the operation (first mode) of the cooling
system 10 when the first and second switching valves 19 and 20 are
switched to a first state.
[0241] In the first state, the first switching valve 19 connects
the inlet 19a with the outlets 19d, 19e, and 19f, and also connects
the inlet 19b with the outlet 19c. Thus, the first switching valve
19 allows the coolant entering the inlet 19a to flow out of the
outlets 19d, 19e, and 19f as indicated by alternate long and short
dashed arrows in FIG. 17, and also allows the coolant entering the
inlet 19b to flow out of the outlet 19c as indicated by a solid
arrow in FIG. 17.
[0242] In the first state, the second switching valve 20 connects
the inlets 20b, 20c, and 20d with the outlet 20e, and also connects
the inlet 20a with the outlet 20f. Thus, the second switching valve
20 allows the coolant entering the inlets 20b, 20c, and 20d to flow
out of the outlet 20e as indicated by alternate long and short
dashed arrows in FIG. 17, and also allows the coolant entering the
inlet 20a to flow out of the outlet 20f as a solid arrow in FIG.
17.
[0243] FIG. 18 shows the operation (second mode) of the cooling
system 10 when the first and second switching valves 19 and 20 are
switched to a second state.
[0244] In the second state, the first switching valve 19 connects
the inlet 19a with the outlets 19d, and 19f, and also connects the
inlet 19b with the outlets 19c and 19e. Thus, the first switching
valve 19 allows the coolant flowing into the inlet 19a to flow from
the outlets 19d, and 19f as indicated by alternate long and short
dashed arrows in FIG. 18, and the coolant flowing into the inlet
19b to flow from the outlets 19c and 19e as solid arrows in FIG.
18.
[0245] In the second state, the second switching valve 20 connects
the inlets 20b and 20d with the outlet 20e and also connects the
inlets 20a, and 20c with the outlet 20f. Thus, the second switching
valve 20 allows the coolant entering the inlets 20b, and 20d to
flow out of the outlet 20e as indicated by alternate long and short
dashed arrows in FIG. 18, and the coolant entering the inlets 20a
and 20c to flow out of the outlet 20f as solid arrows in FIG.
18.
[0246] FIG. 19 shows the operation (third mode) of the cooling
system 10 when the first and second switching valves 19 and 20 are
switched to a third state.
[0247] In the third state, the first switching valve 19 connects
the inlet 19a with the outlet 19d, and also connects the inlet 19b
with the outlets 19c, 19e, and 19f. Thus, the first switching valve
19 allows the coolant entering the inlet 19a to flow out of the
outlet 19d as indicated by an alternate long and short dashed arrow
in FIG. 19, and also allows the coolant entering the inlet 19b to
flow out of the outlets 19c, 19e, and 19f as solid arrows in FIG.
19.
[0248] In the third state, the second switching valve 20 connects
the inlet 20b with the outlet 20e and also connects the inlets 20a,
20c, and 20d with the outlet 20f. Thus, the second switching valve
20 allows the coolant entering the inlet 20b to flow out of the
outlet 20e as indicated by an alternate long and short dashed arrow
in FIG. 19, and also allows the coolant entering the inlets 20a,
20c, and 20d to flow out of the outlet 20f as indicated by a solid
arrow in FIG. 19.
[0249] FIG. 20 shows the operation (fourth mode) of the cooling
system 10 when the first and second switching valves 19 and 20 are
switched to a fourth state.
[0250] In the fourth state, the first switching valve 19 allows the
inlet 19a to communicate with the outlets 19c, 19e, and 19f, and
also allows the inlet 19b to communicate with the outlet 19d. Thus,
the first switching valve 19 allows the coolant flowing into the
inlet 19a to flow from the outlets 19c, 19e, and 19f as indicated
by solid arrows in FIG. 20, and the coolant flowing into the inlet
19b to flow from the outlet 19d as indicated by an alternate long
and short dashed arrow in FIG. 20.
[0251] In the fourth state, the second switching valve 20 connects
the inlet 20b with the outlet 20f and also connects the inlets 20a,
20c, and 20d with the outlet 20e. Thus, the second switching valve
20 allows the coolant entering the inlets 20a, 20c, and 20d to flow
out of the outlet 20e as indicated by solid arrows in FIG. 20, and
the coolant entering the inlet 20b to flow out of the outlet 20f as
an alternate long and short dashed arrow in FIG. 20.
[0252] FIG. 21 shows the operation (fifth mode) of the cooling
system 10 when the first and second switching valves 19 and 20 are
switched to a fifth state.
[0253] In the fifth state, the first switching valve 19 connects
the inlet 19a with the outlet 19c, and also connects the inlet 19b
with the outlets 19d, 19e, and 19f. Thus, the first switching valve
19 allows the coolant flowing into the inlet 19a to flow from the
outlet 19c as indicated by a dashed arrow in FIG. 21, and the
coolant flowing into the inlet 19b to flow from the outlets 19d,
19e, and 19f as indicated by an alternate long and short dashed
arrow in FIG. 21.
[0254] In the fifth state, the second switching valve 20 connects
the inlet 20a with the outlet 20e and also connects the inlets 20b,
20c, and 20d with the outlet 20f. Thus, the second switching valve
20 allows the coolant entering the inlet 20a to flow out of the
outlet 20e as indicated by a dashed arrow in FIG. 21, and also
allows the coolant entering the inlets 20b, 20c, and 20d to flow
out of the outlet 20f as indicated by alternate long and short
dashed arrows in FIG. 21.
[0255] The specific structures of the coolant cooler 14 and the
condenser 50 in this embodiment will be described below with
reference to FIG. 22. The coolant cooler 14 and condenser 50 are
included in one heat exchanger 52 of the tank-and-tube type. One
half of the heat exchanger 52 constitutes the coolant cooler 14,
while the other half of the heat exchanger 52 constitutes the
condenser 50.
[0256] The heat exchanger 52 includes a heat exchanger core (heat
exchanging portion) 52a, tank portions 52b and 52c, and a partition
portion 52d. The heat exchanger core 52a includes a plurality of
tubes through which the coolant and the refrigerant independently
flow. The tubes are stacked on each other in parallel.
[0257] The tank portions 52b and 52c are disposed on both sides of
the tubes to distribute and collect the coolant and refrigerant
with respect to the tubes. The internal spaces of the tank portions
52b and 52c are partitioned into a space for allowing the coolant
to flow therethrough, and another space for allowing the
refrigerant to flow therethrough by a partition member (not
shown).
[0258] The partition portion 52d partitions the insides of the tank
portions 52b and 52c into two spaces in the tube stacking direction
(in the left-right direction of FIG. 22). One side of the heat
exchanger 51 (on the right side of FIG. 22) in the tube stacking
direction with respect to the partition portion 52d constitutes the
coolant cooler 14, whereas the other side of the heat exchanger 52
(on the left side of FIG. 22) in the tube stacking direction with
respect to the partition portion 52d constitutes the condenser 50.
Thus, the partition portion 52d forms a boundary between the
coolant cooler 14 and the condenser 50.
[0259] One side of the heat exchanger core 52a (on the right side
of FIG. 22) in the tube stacking direction with respect to the
partition portion 52d constitutes a heat exchanging portion 52m
(second heat exchanging portion) of the coolant cooler 14. The
other side of the heat exchanger core 52a (on the left side of FIG.
22) in the tube stacking direction with respect to the partition
portion 52d constitutes a heat exchanging portion 52n (first heat
exchanging portion) of the condenser 50.
[0260] Members constituting the heat exchanger core 52a, the tank
portions 52b and 52c, and the partition portion 52d are formed of
metal (for example, an aluminum alloy), and bonded together by
brazing.
[0261] A part of one tank portion 52b serving as the coolant cooler
14 is provided with an inlet (heat medium inlet) 52e for the
coolant and an outlet (refrigerant outlet) 52f for the
refrigerant.
[0262] Further, a part of the other tank portion 52c serving as the
coolant cooler 14 is provided with an outlet (heat medium outlet)
52g for the coolant and an inlet (refrigerant inlet) 52h for the
refrigerant.
[0263] Thus, in the coolant cooler 14, the coolant flows from the
inlet 52e into the tank portion 52b, and is then distributed to the
tubes for the coolant (tubes for the heat medium) by the tank
portion 52b. The coolants after having passed through the tubes for
the coolant are collected into the tank portion 52c to flow out of
the outlet 52g.
[0264] In the coolant cooler 14, the coolant flows from the inlet
52h into the tank portion 52c, and is then distributed to the tubes
for the coolant by the tank portion 52c. The coolants after having
passed through the tubes for the coolant are collected into the
tank portion 52b to flow from the outlet 52f.
[0265] The inlet 52e and outlet 52g for the coolant of the coolant
cooler 14 are disposed between both ends 52o and 52p of the tank
portions 52b and 52c in the tube stacking direction (both ends in
the left-right direction of FIG. 22). In the example shown in FIG.
22, the inlet 52e and outlet 52g are disposed between the partition
portion 52d and the end 52o of the tank portions 52b and 52c in the
tube stacking direction. Thus, the coolant cooler 14 does not allow
the flow of coolant to make a U-turn.
[0266] The inlet 52e and outlet 52g are opened while being oriented
in the direction perpendicular to the tube stacking direction. In
the example shown in FIG. 22, the inlet 52e and outlet 52g are
oriented in the direction parallel to the tubes for the refrigerant
and for the coolant.
[0267] A part of one tank portion 52b serving as the condenser 50
is provided with an inlet (heat medium inlet) 52i for the coolant
and an outlet (refrigerant outlet) 52j for the refrigerant.
Further, a part of the other tank portion 52c serving as the
condenser 50 is provided with an outlet (heat medium outlet) 52k
for the coolant and an inlet (refrigerant inlet) 521 for the
refrigerant.
[0268] Thus, in the condenser 50, the coolant flows from the inlet
52i into the tank portion 52b, and is then distributed to the tubes
for the coolant by the tank portion 52b. The coolants after having
passed through the tubes for the coolant are collected into the
tank portion 52c to flow from the outlet 52k.
[0269] In the condenser 50, the refrigerant flows from the inlet
521 into the tank portion 52c, and is then distributed to the tubes
for the refrigerant by the tank portion 52c. The coolants after
having passed through the tubes for the refrigerant are collected
into the tank portion 52b to flow from the outlet 52j.
[0270] The inlet 52i and outlet 52k for the coolant of the
condenser 50 are disposed between both the ends 52o and 52p of the
tank portions 52b and 52c in the tube stacking direction (both ends
in the left-right direction of FIG. 22). In the example shown in
FIG. 22, the inlet 52i and outlet 52k are disposed between the
partition portion 52d and the other end 52p of the tank portions
52b and 52c in the tube stacking direction. Thus, the condenser 50
does not allow the flow of coolant to make a U-turn.
[0271] The inlet 52i and outlet 52k are oriented in the direction
perpendicular to the tube stacking direction. In the example shown
in FIG. 22, the inlet 52e and outlet 52g are oriented in the
direction parallel to the tubes for the refrigerant and for the
coolant.
[0272] The heat exchanger 52 is not limited to the tank-and-tube
type heat exchanger, and can be applied to other types of heat
exchangers. For example, a laminate-type heat exchanger including a
lamination of a number of plate members may be adopted.
[0273] A control process executed by the controller 40 of this
embodiment will be described with reference to FIG. 23. The
controller 40 executes a computer program according to a flowchart
of FIG. 23.
[0274] First, in step S100, it is determined whether the air
conditioning switch 44 is turned on or not. When the air
conditioner 44 is determined to be turned on, the cooling is
considered to be necessary, and then the operation proceeds to step
S110. In step S110, it is determined whether the temperature of
coolant detected by the water temperature sensor 43 is lower than
40 degrees or not.
[0275] When the temperature of coolant detected by the water
temperature sensor 43 is determined to be lower than 40 degrees,
the temperature of the coolant (intermediate-temperature coolant)
cooled by the outside air in the radiator 13 is considered to be
low, and then the operation proceeds to step S120. In step S120,
the first mode shown in FIG. 17 is performed.
[0276] In the first mode, the controller 40 controls the electric
motor 30 for a switching valve such that the first and second
switching valves 19 and 20 are brought into the first state shown
in FIG. 17 to thereby operate the first and second pumps 11 and 12
and the compressor 23.
[0277] Thus, the first switching valve 19 connects the inlet 19a
with the outlets 19d, 19e, and 19f, and also connects the inlet 19b
with the outlet 19c. The second switching valve 20 connects the
inlets 20b, 20c, and 20d with the outlet 20e, and also connects the
inlet 20a with the outlet 20f.
[0278] Accordingly, the first coolant circuit
(intermediate-temperature coolant circuit) is formed of the first
pump 11, the battery cooler 15, the inverter cooler 16, the
condenser 50, the heater core 51, and the radiator 13, whereas the
second coolant circuit (low-temperature coolant circuit) is formed
of the second pump 12, the coolant cooler 14, and the cooler core
18.
[0279] That is, as indicated by alternate long and short dashed
arrows in FIG. 17, the coolant discharged from the first pump 11 is
branched by the first switching valve 19 into the battery cooler
15, the inverter 16, and the condenser 50 to flow in parallel
through the battery cooler 15, the inverter cooler 16, and the
condenser 50. The coolant flowing through the condenser 50 flows in
series through the heater core 51. The coolants flowing through the
heater core 51, through the battery cooler 15, and through the
inverter cooler 16 are collected by the second switching valve 20
to flow through the radiator 13, thereby being sucked into the
first pump 11.
[0280] On the other hand, as indicated by a solid arrow in FIG. 17,
the coolant discharged from the second pump 12 flows through the
coolant cooler 14 and the cooler core 18 in series via the first
switching valve 19, and is then sucked into the second pump 12 via
the second switching valve 20.
[0281] In this way, in the first mode, the intermediate-temperature
coolant cooled by the radiator 13 flows through the battery cooler
15, the inverter cooler 16, the condenser 50, and the heater core
51, whereas the low-temperature coolant cooled by the coolant
cooler 14 flows through the cooler core 18.
[0282] Thus, in the battery cooler 15 and the inverter cooler 16,
the battery and inverter are cooled by the intermediate-temperature
coolant. In the condenser 50, the intermediate-temperature coolant
is heated by exchanging heat with the high-pressure refrigerant of
the refrigeration cycle 22. In the cooler core 18, the blast air
into the vehicle interior is cooled by exchanging heat between the
low-temperature coolant and the blast air into vehicle
interior.
[0283] The intermediate-temperature coolant heated by the condenser
50 exchanges heat with the blast air having passed through the
cooler core 18 when flowing through the heater core 51. Thus, the
heater core 51 heats the blast air having passed through the cooler
core 18. That is, the blast air cooled and dehumidified by the
cooler core 18 can be heated by the heater core 51 to form a
conditioned air at a desired temperature.
[0284] For example, when the outside air temperature is about
15.degree. C., the intermediate coolant cooled by the outside air
in the radiator 13 becomes at about 25.degree. C., so that the
intermediate-temperature coolant can sufficiently cool the battery
and the inverter.
[0285] The low-temperature coolant cooled by the low-pressure
refrigerant of the refrigeration cycle 22 in the coolant cooler 14
becomes at about 0.degree. C., so that the low-temperature coolant
can sufficiently cool the blast air into the vehicle interior.
[0286] In the first mode, the battery and the inverter are cooled
by the outside air, which can effectively achieve the energy saving
as compared to the case in which the battery and the inverter are
cooled by the low-pressure refrigerant of the refrigeration cycle
22.
[0287] In contrast, in step S110, when the temperature of the
coolant detected by the water temperature sensor 43 is determined
not to be lower than 40 degrees, the temperature of the
intermediate-temperature coolant is considered to be higher, and
then the operation proceeds to step S130. In step S130, it is
determined whether or not the temperature of the coolant detected
by the water temperature sensor 43 is 40 degrees or more to less
than 50 degrees.
[0288] When the temperature of the coolant detected by the water
temperature sensor 43 is determined to be 40 degrees or more, and
less than 50 degrees, the operation proceeds to step S140, in which
the second mode is performed as shown in FIG. 18.
[0289] In the second mode, the controller 40 controls the electric
motor 30 for a switching valve such that the first and second
switching valves 19 and 20 are brought into the second state shown
in FIG. 18 to thereby operate the first and second pumps 11 and 12
and the compressor 23.
[0290] Thus, the first switching valve 19 connects the inlet 19a
with the outlets 19d and 19f, and also connects the inlet 19b with
the outlets 19c and 19e. The second switching valve 20 connects the
inlets 20b and 20d with the outlet 20e, and also connects the
inlets 20a and 20c with the outlet 20f.
[0291] Accordingly, the first coolant circuit
(intermediate-temperature coolant circuit) is formed of the first
pump 11, the inverter cooler 16, the condenser 50, the heater core
51, and the radiator 13, whereas the second coolant circuit
(low-temperature coolant circuit) is formed of the second pump 12,
the coolant cooler 14, the cooler core 18, and the battery cooler
15.
[0292] That is, as indicated by alternate long and short dashed
arrows in FIG. 18, the coolant discharged from the first pump 11 is
branched into the inverter cooler 16 and the condenser 50 by the
first switching valve 19 to flow in parallel through the inverter
cooler 16 and the condenser 50. The coolant flowing through the
condenser 50 flows in series through the heater core 51. The
coolants flowing through the heater core 51 and through the
inverter cooler 16 are collected by the second switching valve 20
to flow through the radiator 13, thereby being sucked into the
first pump 11.
[0293] On the other hand, as indicated by solid arrows in FIG. 18,
the coolant discharged from the second pump 12 is branched into the
coolant cooler 14 and the battery cooler 15 by the first switching
valve 19 to flow in parallel through the coolant cooler 14 and the
battery cooler 15. The coolant flowing through the coolant cooler
14 flows in series through the cooler core 18. The coolants flowing
through the cooler core 18 and through the battery cooler 15 are
collected by the second switching valve 20 to be sucked into the
second pump 12.
[0294] Thus, in the second mode, the intermediate-temperature
coolant cooled by the radiator 13 flows through the inverter cooler
16, the condenser 50, and the heater core 51, whereas the
low-temperature coolant cooled by the coolant cooler 14 flows
through the cooler core 18 and the battery cooler 15.
[0295] Thus, the inverter can be cooled by the
intermediate-temperature coolant, and the battery can be cooled by
the low-temperature coolant. Additionally, like the first mode, the
blast air cooled and dehumidified by the cooler core 18 is heated
by the heater core 51, which can make the conditioned air at the
desired temperature.
[0296] For example, when the outside air temperature is about
30.degree. C., the intermediate-temperature coolant cooled by the
outside air in the radiator 13 becomes at a temperature of about
40.degree. C., so that the intermediate-temperature coolant can
sufficiently cool the inverter.
[0297] The low-temperature coolant cooled by the low-pressure
refrigerant of the refrigeration cycle 22 in the coolant cooler 14
becomes at about 0.degree. C., so that the battery and the blast
air into the vehicle interior can be sufficiently cooled by the
low-temperature coolant.
[0298] Since in the second mode the battery is cooled by the
low-pressure refrigerant of the refrigeration cycle 22, the battery
can be sufficiently cooled even when the outside air cannot cool
the battery adequately because of the high temperature of the
outside air.
[0299] In step S130, when the temperature of coolant detected by
the water temperature sensor 43 is determined to be 40 degrees or
more to less than 50 degrees, the temperature of the
intermediate-temperature coolant is considered to be very high, and
then the operation proceeds to step S150. In step S150, the third
mode shown in FIG. 19 is performed.
[0300] In the third mode, the controller 40 controls the electric
motor 30 for a switching valve such that the first and second
switching valves 19 and 20 are brought into the third state shown
in FIG. 19 to thereby operate the first and second pumps 11 and 12
and the compressor 23.
[0301] Thus, the first switching valve 19 connects the inlet 19a
with the outlet 19d and also connects the inlet 19b with the
outlets 19c, 19e, and 19f. The second switching valve 20 connects
the inlet 20b with the outlet 20e, and also connects the inlets
20a, 20c, and 20d with the outlet 20f.
[0302] Accordingly, the first coolant circuit
(intermediate-temperature coolant circuit) is formed of the first
pump 11, the condenser 50, the heater core 51, and the radiator 13,
whereas the second coolant circuit (low-temperature coolant
circuit) is formed of the second pump 12, the coolant cooler 14,
the cooler core 18, the battery cooler 15, and the inverter cooler
16.
[0303] That is, as indicated by an alternate long and short dashed
arrow in FIG. 19, the coolant discharged from the first pump 11
flows through the condenser 50 and heater core 51 in series via the
first switching valve 19, and then through the radiator 13 via the
second switching valve 20, thereby being sucked into the first pump
11.
[0304] On the other hand, as indicated by solid arrows in FIG. 19,
the coolant discharged from the second pump 12 is branched into the
coolant cooler 14, the battery cooler 15, and the inverter cooler
16 by the first switching valve 19. The coolant flowing through the
coolant cooler 14 flows in series through the cooler core 18. The
coolants flowing through the cooler core 18, through the battery
cooler 15, and through the inverter cooler 16 are collected by the
second switching valve 20 to be sucked into the second pump 12.
[0305] In this way, in the third mode, the intermediate-temperature
coolant cooled by the radiator 13 flows through the condenser 50
and the heater core 51, whereas the low-temperature coolant cooled
by the coolant cooler 14 flows through the cooler core 18, the
battery cooler 15, and the inverter cooler 16.
[0306] Thus, the battery and the inverter can be cooled by the
low-temperature coolant, and like the first and second modes, the
blast air cooled and dehumidified by the cooler core 18 is heated
by the heater core 51, which can make the conditioned air at the
desired temperature.
[0307] For example, when the outside air temperature is about
40.degree. C., the intermediate-temperature coolant cooled by the
outside air in the radiator 13 becomes at about 50.degree. C. The
low-temperature coolant cooled by the low-pressure refrigerant of
the refrigeration cycle 22 in the coolant cooler 14 becomes at
about 0.degree. C., so that the blast air into the vehicle
interior, the battery, and the inverter can be sufficiently cooled
by the low-temperature coolant.
[0308] Since in the third mode the battery and the inverter are
cooled by the low-pressure refrigerant of the refrigeration cycle
22, the battery and the inverter can be sufficiently cooled even
when the outside air cannot cool the battery and the inverter
adequately because of the very high temperature of the outside
air.
[0309] When the air conditioning switch 44 is determined not to be
turned on in step S100, the cooling is considered not to be
necessary, and then the operation proceeds to step S160. In step
S160, it is determined whether the outside air temperature detected
by the outside air sensor 42 is lower than 15 degrees or not.
[0310] When the outside air temperature detected by the outside air
sensor 42 is determined to be 15 degrees or less, the high heating
capacity is considered to be necessary, and then the operation
proceeds to step S170, in which a fourth mode is performed as shown
in FIG. 20.
[0311] In the fourth mode, the controller 40 controls the electric
motor 30 for a switching valve such that the first and second
switching valves 19 and 20 are brought into the fourth state shown
in FIG. 20 to thereby operate the first and second pumps 11 and 12
and the compressor 23.
[0312] Thus, the first switching valve 19 connects the inlet 19a
with the outlets 19c, 19e, and 19f, and also connects the inlet 19b
with the outlet 19d. The second switching valve 20 connects the
inlets 20a, 20c, and 20d with the outlet 20e, and also connects the
inlet 20b with the outlet 20f.
[0313] Accordingly, a first coolant circuit (low-temperature
coolant circuit) is formed of the first pump 11, the coolant cooler
14, the cooler core 18, the battery cooler 15, the inverter cooler
16, and the radiator 13, whereas a second coolant circuit
(intermediate-temperature coolant circuit) is formed of the second
pump 12, the condenser 50, and the heater core 51.
[0314] That is, as indicated by solid arrows in FIG. 20, the
coolant discharged from the first pump 11 is branched into the
coolant cooler 14, the battery cooler 15, and the inverter cooler
16 by the first switching valve 19. The coolant flowing through the
coolant cooler 14 flows in series through the cooler core 18. The
coolants flowing through the cooler core 18, through the battery
cooler 15, and through the inverter cooler 16 are collected by the
second switching valve 20 to flow through the radiator 13, thereby
being sucked into the first pump 11.
[0315] On the other hand, as indicated by an alternate long and
short dashed arrow in FIG. 20, the coolant discharged from the
second pump 12 flows through the condenser 50 and the heater core
51 in series via the first switching valve 19, and is then sucked
into the second pump 12 via the second switching valve 20.
[0316] Thus, in the fourth mode, the low-temperature coolant cooled
by the coolant cooler 14 flows through the cooler core 18, the
battery cooler 15, and the inverter cooler 16, which can cool the
blast air into the vehicle interior, the battery, and the inverter
by the low-temperature coolant.
[0317] In the fourth mode, the low-temperature coolant cooled by
the coolant cooler 14 flows through the radiator 13, allowing the
coolant to absorb heat from the outside air in the radiator 13.
Then, the coolant that has absorbed heat from the outside air in
the radiator 13 exchanges heat with the refrigerant of the
refrigeration cycle 22 in the coolant cooler 14 to dissipate heat
therefrom. Thus, in the coolant cooler 14, the refrigerant of the
refrigeration cycle 22 absorbs heat from the outside air via the
coolant.
[0318] The refrigerant which has absorbed heat from the outside air
in the coolant cooler 14 exchanges heat with the coolant of the
intermediate-temperature coolant circuit in the condenser 50,
whereby the coolant of the intermediate-temperature coolant circuit
is heated. The coolant of the intermediate-temperature circuit
heated by the condenser 50 exchanges heat with the blast air having
passed through the cooler core 18 in flowing through the heater
core 51, thereby dissipating heat therefrom. Thus, the heater core
51 heats the blast air having passed through the cooler core 18.
Accordingly, the fourth mode can achieve heat pump heating that
heats the vehicle interior by absorbing heat from the outside
air.
[0319] For example, when the outside air temperature is 10.degree.
C., the intermediate-temperature coolant heated by the condenser 50
becomes at about 50.degree. C., so that the blast air having passed
through the cooler core 18 can be sufficiently heated by the
intermediate-temperature coolant.
[0320] The low-temperature coolant cooled by the low-pressure
refrigerant of the refrigeration cycle 22 in the coolant cooler 14
is at about 0.degree. C., so that the battery and the inverter can
be sufficiently cooled by the low-temperature coolant.
[0321] Note that the fourth mode can achieve the dehumidification
heating which involves allowing the heater core 51 to heat the
blast air cooled and dehumidified by the cooler core 18.
[0322] In the following step S180, it is determined whether or not
the inside air temperature detected by the inside air sensor 41 is
25 degrees or higher. When the inside air temperature detected by
the inside air sensor 41 is determined not to be 25 degrees or
more, the high heating capacity is considered to be necessary, and
then the operation returns to step S180. Thus, until the inside air
temperature is increased to 25 degrees or more, the fourth mode is
performed.
[0323] When the inside air temperature detected by the inside air
sensor 41 is determined to be 25 degrees or more, the high heating
capacity is considered not to be necessary, and then the operation
proceeds to step S190, in which a fifth mode is performed as shown
in FIG. 21.
[0324] In the fifth mode, the controller 40 controls the electric
motor 30 for a switching valve such that the first and second
switching valves 19 and 20 becomes the fifth state shown in FIG.
21.
[0325] Thus, the first switching valve 19 connects the inlet 19a
with the outlet 19c and also connects the inlet 19b with the
outlets 19d, 19e, and 19f. The second switching valve 20 connects
the inlet 20a with the outlet 20e, and also connects the inlets
20b, 20c, and 20d with the outlet 20f.
[0326] Accordingly, a first coolant circuit (low-temperature
coolant circuit) is formed of the first pump 11, the coolant cooler
14, the cooler core 18, and the radiator 13, whereas a second
coolant circuit (intermediate-temperature coolant circuit) is
formed of the second pump 12, the battery cooler 15, the inverter
cooler 16, the condenser 50, and the heater core 51.
[0327] At this time, the second pump 12 is operated to thereby stop
the first pump 11 and compressor 23. Thus, in the first coolant
circuit indicated by dashed arrows in FIG. 21, the coolant does not
circulate therethrough.
[0328] On the other hand, as indicated by alternate long and short
dashed arrows in FIG. 21, in the second coolant circuit, the
coolant discharged from the second pump 12 is branched into the
battery cooler 15, the inverter cooler 16, and the condenser 50 by
the first switching valve 19. The coolant flowing through the
condenser 50 flows in series through the heater core 51. The
coolants flowing through the heater core 51, through the battery
cooler 15, and through the inverter cooler 16 are collected by the
second switching valve 20 to be sucked into the second pump 12.
[0329] Thus, in the fifth mode, the coolant which has absorbed heat
from the battery in the battery cooler 15 and the coolant which has
absorbed heat from the inverter in the inverter cooler 16 flow
through the heater core 51, so that the blast air into the vehicle
interior can be heated by exhaust heat from the battery and
inverter.
[0330] For example, when the outside air temperature is 10.degree.
C., the coolant heated by the battery cooler 15 and the inverter
cooler 16 becomes at about 30.degree., whereby the blast air into
the vehicle interior can be heated to 25 degrees or more with the
inside air temperature maintained at 25 degrees or more.
[0331] In this embodiment, when the outside air temperature is
lower than a predetermined temperature (15.degree. C. in this
embodiment), the forth mode or the fifth mode can be carried out to
perform heating.
[0332] In the fourth mode, the coolant circulates between the
coolant cooler 14 and the first pump 11, whereas the coolant heat
medium circulates between the condenser 50 and the second pump
12.
[0333] Thus, the coolant cooled by the coolant cooler 14 flows
through the radiator 13, so that the refrigerant of the
refrigeration cycle 22 in the coolant cooler 14 can absorb heat
from the outside air via the coolant flowing through the radiator
13. Thus, the heat of the outside air can be pumped up from the
coolant cooler 14 (low-pressure side heat exchanger) of the
refrigeration cycle 22 to the condenser 50 (high-pressure side heat
exchanger).
[0334] The heat of the outside air pumped up by the refrigeration
cycle 22 can heat the blast air into the vehicle interior by use of
the heater core 51, which can achieve the heat pump heating which
involves heating the vehicle interior by absorption of the heat
from the outside air.
[0335] In the fifth mode, the coolant circulates between each of
the battery coolant 15 and the heater core 51, and the second pump
12, whereby the operation of the first pump 11 is stopped. Thus,
the coolant absorbs heat from the battery in the battery cooler 15,
and the coolant which has absorbed the heat from the battery heats
the blast air into the vehicle interior by the heater core 51, so
that the exhaust heat from the battery can be used to heat the
vehicle interior.
[0336] In this embodiment, the coolant cooler 14 and the condenser
50 are integrated into one heat exchanger 52, which can
significantly improve the productivity as compared to the case
where the coolant cooler 14 and the condenser 50 are formed of
different heat exchangers.
[0337] Further, in this embodiment, the inlet 52e and outlet 52g
for the coolant of the coolant cooler 14 are disposed between both
the ends 52o and 52p of the tank portions 52b and 52c in the tube
stacking direction, which can increase the flexibility in
connection of the pipes and arrangement of the heat exchangers as
compared to the case where the inlet 52e and outlet 52g for the
coolant are disposed at both the ends 52o and 52p of the tank
portions 52b and 52c in the tube stacking direction. The coolant
cooler 14 does not allow the flow of coolant to make a U-turn, and
thus can reduce the loss of pressure of the coolant in the coolant
cooler 14.
[0338] Likewise, the inlet 52i and outlet 52k for the coolant of
the condenser 50 are disposed between both the ends 52o and 52p of
the tank portions 52b and 52c in the tube stacking direction, which
can increase the flexibility in connection of the pipes and
arrangement of the heat exchangers as compared to the case where
the inlet 52i and outlet 52k for the coolant are disposed at both
the ends 52o and 52p of the tank portions 52b and 52c in the tube
stacking direction. The condenser 50 does not allow the flow of
coolant to make a U-turn, and thus can reduce the loss of pressure
of the coolant in the condenser 50.
[0339] That is, at least one of the refrigerant inlets 52h and 52l,
refrigerant outlets 52f and 52j, coolant inlets 52e and 52i, and
coolant outlets 52g and 52k is disposed between both the ends 52o
and 52p of the tank portions 52b and 52c in the tube stacking
direction. Such a system can increase the flexibility of connection
of the pipes and arrangement of the heat exchangers as compared to
the system in which all the refrigerant inlets 52h and 52l,
refrigerant outlets 52f and 52j, coolant inlets 52e and 52i, and
coolant outlets 52g and 52k are disposed at both the ends 52o and
52p of the tank portions 52b and 52c.
Second Embodiment
[0340] Although in the first embodiment, the low-pressure
refrigerant of the refrigeration cycle 22 is evaporated by the
coolant cooler 14 to thereby cool the blast air into the vehicle
interior by the cooler core 18, in a second embodiment, as shown in
FIG. 24, the low-pressure refrigerant of the refrigeration cycle 22
is evaporated in the coolant cooler 14 and an evaporator 55,
thereby cooling the blast air into the vehicle interior by the
evaporator 55 of the refrigeration cycle 22.
[0341] The evaporator 55 allows the refrigerant to flow in parallel
to the coolant cooler 14. Specifically, the refrigerant cycle 22
has a branch portion 56 for refrigerant flow that is located
between the refrigerant discharge side of the compressor 23 and the
refrigerant inlet side of the expansion valve 25, and a collection
portion 57 for refrigerant flow that is located between the
refrigerant outlet side of the coolant cooler 14 and the
refrigerant suction side of the compressor 23. An expansion valve
58 and the evaporator 55 are connected between the branch portion
56 and the collection portion 57.
[0342] The expansion valve 58 is a decompression device for
decompressing and expanding a liquid-phase refrigerant branched by
the branch portion 56. The evaporator 55 is adapted to evaporate a
low-pressure refrigerant so as to cool the blast air by exchanging
heat between the blast air into the vehicle interior and the
low-pressure refrigerant decompressed and expanded by the expansion
valve 25.
[0343] An electromagnetic valve 59 (opening and closing valve) is
connected between the branch portion 56 and the expansion valve 25.
When the electromagnetic valve 59 is opened, the refrigerant
discharged from the compressor 23 flows through the expansion valve
25 and the coolant cooler 14. When the electromagnetic valve 59 is
closed, the flow of refrigerant toward the expansion valve 25 and
the coolant cooler 14 is interrupted. The operation of the
electromagnetic valve 59 is controlled by the controller 40.
[0344] The refrigeration cycle 22 includes a supercooler 60. The
supercooler 60 is a heat exchanger (auxiliary heat exchanger) for
further cooling the liquid-phase refrigerant to increase a
supercooling degree of the refrigerant by exchanging heat between
the coolant and the liquid-phase refrigerant condensed by the
condenser 50.
[0345] The coolant inlet side of the supercooler 60 is connected to
the outlet 19e of the first switching valve 19. The coolant outlet
side of the supercooler 60 is connected to the coolant inlet side
of the battery cooler 15.
[0346] In this embodiment, the battery cooler 15 and the battery
are accommodated in an insulating container formed of thermal
insulating material. Thus, cold energy stored in the battery can be
prevented from escaping outward, thereby keeping the battery
cold.
[0347] The first switching valve 19 is configured to be capable of
switching between two types of communication states between the
inlets 19a and 19b and the outlets 19c, 19d, 19e, and 19f. The
second switching valve 20 is also configured to be capable of
switching between two types of communication states between the
inlets 20a, 20b, 20c, and 20d and the outlets 20e, and 20f.
[0348] FIG. 25 shows the operation (first mode) of the cooling
system 10 when the first and second switching valves 19 and 20 are
switched to a first state, and the electromagnetic valve 59 is
switched to an opened state. FIG. 26 shows the operation (second
mode) of the cooling system 10 when the first and second switching
valves 19 and 20 are switched to the first state, and the
electromagnetic valve 59 is switched to a closed state.
[0349] In the first and second states, the first switching valve 19
connects the inlet 19a with the outlets 19d, and 19f, and also
connects the inlet 19b with the outlets 19c and 19e. Thus, the
first switching valve 19 allows the coolant entering the inlet 19a
to flow out of the outlets 19d, and 19f as indicated by alternate
long and short dashed arrows in FIGS. 25 and 26, and also allows
the coolant entering the inlet 19b to flow out of the outlets 19c
and 19e as solid arrows in FIGS. 25 and 26.
[0350] In the first and second states, the second switching valve
20 connects the inlets 20b and 20d with the outlet 20e and also
connects the inlets 20a, and 20c with the outlet 20f. Thus, the
second switching valve 20 allows the coolant entering the inlets
20b, and 20d to flow out of the outlet 20e as indicated by
alternate long and short dashed arrows in FIGS. 25 and 26, and also
allows the coolant entering the inlets 20a and 20c to flow out of
the outlet 20f as indicated by solid arrows in FIGS. 25 and 26.
[0351] FIG. 27 shows the operation (third mode) of the cooling
system 10 when the first and second switching valves 19 and 20 are
switched to the second state.
[0352] In the third state, the first switching valve 19 allows the
inlet 19a to communicate with the outlets 19c, and 19f, and also
allows the inlet 19b to communicate with the outlet 19d, thereby
closing the outlet 19e. Thus, the first switching valve 19 allows
the coolant flowing into the inlet 19a to flow from the outlets 19c
and 19f as indicated by solid arrows in FIG. 27, and the coolant
flowing into the inlet 19b to flow from the outlet 19d as indicated
by an alternate long and short dashed arrow in FIG. 27, thereby
preventing the coolant from flowing out of the outlet 19e.
[0353] In the third state, the second switching valve 20 connects
the inlets 20a and 20d with the outlet 20e and also connects the
inlet 20b with the outlet 20f, thereby closing the inlet 20c. Thus,
the second switching valve 20 allows the coolant entering the
inlets 20a and 20d to flow out of the outlet 20e as indicated by
solid arrows in FIG. 27, and also allows the coolant entering the
inlet 20b to flow out of the outlet 20f as indicated by an
alternate long and short dashed arrow in FIG. 27, thereby
preventing the coolant from flowing out of the inlet 20c.
[0354] The specific structures of the coolant cooler 14, the
condenser 50, and the supercooler 60 in this embodiment will be
described below with reference to FIG. 28.
[0355] The coolant cooler 14, the condenser 50, and the supercooler
60 are included in one heat exchanger 61 of the tank-and-tube type.
Specifically, the supercooler (auxiliary heat exchanger) 60 is
disposed between the coolant cooler 14 and the condenser 50.
[0356] The heat exchanger 61 includes a heat exchanger core (heat
exchanging portion) 61a, tank portions 61b and 61c, and two
partition portions 61d and 61d. The heat exchanger core 61a
includes a plurality of tubes through which the coolant and the
refrigerant independently flow. The tubes are stacked on each other
in parallel.
[0357] The tank portions 61b and 61c are disposed on both sides of
the tubes to distribute and collect the coolant and refrigerant
with respect to the tubes. The internal spaces of the tank portions
61b and 61c are partitioned into a space for allowing the coolant
to flow therethrough, and another space for allowing the
refrigerant to flow therethrough by a partition member (not
shown).
[0358] The two partition portions 61d and 61d partition the insides
of the tank portions 61b and 61c into three spaces in the tube
stacking direction (in the left-right direction of FIG. 28). One
side of the heat exchanger 61 (on the right side of FIG. 28) in the
tube stacking direction with respect to the partition portion 61d
constitutes the coolant cooler 14, whereas the other side of the
heat exchanger 52 (on the left side of FIG. 28) in the tube
stacking direction with respect to the partition portion 61d
constitutes the condenser 50, whereby a gap between the partitions
61d and 61d serves as the supercooler 60.
[0359] Thus, one partition portion 61d forms a boundary (first
boundary) between the coolant cooler 14 and the supercooler 60, and
the other partition portion 61d forms another boundary (second
boundary) between the supercooler 60 and the condenser 50.
[0360] A part of the heat exchanger core 61a of the heat exchanger
61 on one side in the tube stacking direction (on the right side of
FIG. 28) with respect to the partition portion 61d constitutes a
heat exchanging portion (second heat exchanging portion) of the
coolant cooler 14. A part of the heat exchanger 61 on the other
side in the tube stacking direction (on the left side of FIG. 28)
with respect to the partition portion 61d constitutes a heat
exchanging portion (first heat exchanging portion) of the condenser
50. A part of the heat exchanger between the partition portions 61d
and 61d constitutes a further heat exchanging portion (auxiliary
heat exchanging portion) of the supercooler 60.
[0361] Members constituting the heat exchanger core 61a, the tank
portions 61b and 61c, and the partition portion 61d are formed of
metal (for example, an aluminum alloy), and bonded together by
brazing.
[0362] A part of one tank portion 61b serving as the coolant cooler
14 is provided with an inlet 61e for the coolant and an outlet 61f
for the refrigerant. A part of the other tank portion 61c serving
as the coolant cooler 14 is provided with an outlet 61g for the
coolant and an inlet 61h for the refrigerant.
[0363] Thus, in the coolant cooler 14, the coolant flows from an
inlet 61e into the tank portion 61b, and is then distributed to the
tubes for the coolant by the tank portion 61b. The coolants after
having passed through the tubes for the coolant are collected into
the tank portion 61c to flow from the outlet 61g.
[0364] In the coolant cooler 14, the refrigerant flows from the
inlet 61h into the tank portion 61c, and is then distributed to the
tubes for the refrigerant by the tank portion 61c. The refrigerants
after having passed through the tubes for the refrigerant are
collected into the tank portion 61b to flow from the outlet
61f.
[0365] The inlet 61e for the coolant of the coolant cooler 14 is
disposed between both ends 61q and 61r of the tank portion 61b in
the tube stacking direction (both ends in the left-right direction
of FIG. 28). The outlet 61g for the coolant of the coolant cooler
14 is disposed inside both ends of the tank portion 61c in the tube
stacking direction (both ends in the left-right direction of FIG.
28). In the example shown in FIG. 28, the inlet 61e and outlet 61g
for the coolant are disposed between one end 61q and the partition
portion 61d (specifically, the partition portion 61d forming the
boundary between the coolant cooler 14 and the supercooler 60) of
the tank portions 61b and 61c in the tube stacking direction. Thus,
the coolant cooler 14 does not allow the flow of coolant to make a
U-turn.
[0366] The inlet 61e and outlet 61g are oriented in the direction
perpendicular to the tube stacking direction. In the example shown
in FIG. 28, the inlet 61e and outlet 61g are oriented in the
direction parallel to the tubes for the refrigerant and for the
coolant.
[0367] A part of one tank portion 61b serving as the condenser 50
is provided with an inlet 61i for the coolant. A hole 61j for
allowing the refrigerant to flow therethrough is formed in a part
of the partition portion 61d for partitioning the inner space of
the tank portion 61b into a tank space for the condenser 50 and
another tank space for the supercooler 60. A part of the other tank
portion 61c serving as the condenser 50 is provided with an outlet
61k for the coolant and an inlet 61i for the refrigerant.
[0368] Thus, in the condenser 50, the coolant flows from the inlet
61i into the tank portion 61b, and is then distributed to the tubes
for the coolant by the tank portion 61b. The coolants after having
passed through the tubes for the coolant are collected into the
tank portion 61c to flow from the outlet 61k.
[0369] In the condenser 50, the refrigerant flows from the inlet
61i into the tank portion 61c, and is then distributed to the tubes
for the refrigerant by the tank portion 61c. The refrigerants after
having passed through the tubes for the refrigerant are collected
into the tank portion 61b to flow from the supercooler 60 via the
hole 61j of the partition portion 61d.
[0370] The inlet 61i for the coolant of the condenser 50 is
disposed between both the ends 61q and 61r of the tank portion 61b
in the tube stacking direction (both ends in the left-right
direction of FIG. 28). The outlet 61k for the coolant of the
condenser 50 is disposed inside both the ends 61q and 61r of the
tank portion 61c in the tube stacking direction. In the example
shown in FIG. 28, the inlet 61i and outlet 61k for the coolant is
disposed between the other end 61r and the partition portion 61d
(partition portion 61d forming a boundary between the supercooler
60 and the condenser 50) of the tank portions 61b and 61c in the
tube stacking direction. Thus, the condenser 50 does not allow the
flow of coolant to make a U-turn.
[0371] The inlet 61i and outlet 61k are oriented in the direction
perpendicular to the tube stacking direction. In the example shown
in FIG. 28, the inlet 61i and outlet 61k are oriented in the
direction parallel to the tubes for the refrigerant and for the
coolant.
[0372] A part of one tank portion 61b serving as the supercooler 60
is provided with an outlet 61m for the coolant. A part of the other
tank portion 61c serving as the supercooler 60 is provided with an
inlet 61n for the coolant and an outlet 61o for the
refrigerant.
[0373] Thus, in the condenser 60, the coolant flows from the inlet
61n into the tank portion 61c, and is then distributed to the tubes
for the coolant by the tank portion 61c. The coolants after having
passed through the tubes for the coolant are collected into the
tank portion 61b to flow from the outlet 61m.
[0374] In the supercooler 60, the refrigerant flows into the tank
portion 61b through the hole 61j of the partition portion 61d, and
is then distributed to the tubes for the refrigerant by the tank
portion 61b. The refrigerants after having passed through the tubes
for the refrigerant are collected into the tank portion 61c to flow
from the outlet 61o.
[0375] The inlet 61n and outlet 610 for the coolant of the
supercooler 60 are disposed between both the ends 61q and 61r of
the tank portion 61b in the tube stacking direction. The outlet 61m
for the coolant of the supercooler 60 is disposed between both the
ends 61q and 61r of the tank portion 61c in the tube stacking
direction. In the example shown in FIG. 28, the inlet 61n and
outlet 61m for the coolant and the outlet 610 for the refrigerant
are disposed between two partition portions 61d. Thus, the coolant
cooler 60 does not allow the flow of coolant to make a U-turn.
[0376] The inlet 61n and outlet 61m for the coolant are oriented in
the direction perpendicular to the tube stacking direction. The
inlet 61n and outlet 610 for the coolant are oriented in the
direction parallel to the tubes for the refrigerant and for the
coolant. The outlet 61o for the refrigerant is oriented in the
direction perpendicular to the tube stacking direction. The outlet
61o for the refrigerant is oriented in the direction parallel to
the tubes for the refrigerant and for the coolant.
[0377] Now, the operation of the above-mentioned structure will be
described. When the battery is charged with an external power
source, the controller 40 performs the first mode shown in FIG.
25.
[0378] In the first mode, the controller 40 controls the electric
motor 30 for a switching valve such that the first and second
switching valves 19 and 20 are brought into the first state shown
in FIG. 25 to operate the first and second pumps 11 and 12 and the
compressor 23, thereby switching the electromagnetic valve 59 to
the opened state.
[0379] Thus, the first switching valve 19 connects the inlet 19a
with the outlets 19d and 19f, and also connects the inlet 19b with
the outlets 19c and 19e. The second switching valve 20 connects the
inlets 20b and 20d with the outlet 20e, and also connects the
inlets 20a and 20c with the outlet 20f.
[0380] Accordingly, the first coolant circuit
(intermediate-temperature coolant circuit) is formed of the first
pump 11, the inverter cooler 16, the condenser 50, the heater core
51, and the radiator 13, whereas the second coolant circuit
(low-temperature coolant circuit) is formed of the second pump 12,
the coolant cooler 14, the supercooler 60, and the battery cooler
15.
[0381] That is, as indicated by alternate long and short dashed
arrows in FIG. 25, the coolant discharged from the first pump 11 is
branched into the inverter cooler 16 and the condenser 50 by the
first switching valve 19 to flow in parallel through the inverter
cooler 16 and the condenser 50. The coolant flowing through the
condenser 50 flows in series through the heater core 51. The
coolants flowing through the heater core 51 and through the
inverter cooler 16 are collected by the second switching valve 20
to flow through the radiator 13, thereby being sucked into the
first pump 11.
[0382] On the other hand, as indicated by solid arrows in FIG. 25,
the coolant discharged from the second pump 12 is branched into the
coolant cooler 14 and the supercooler 60 by the first switching
valve 19 to flow in parallel through the coolant cooler 14 and the
supercooler 60. The coolant flowing through the supercooler 60
flows in series through the battery cooler 15. The coolants flowing
through the battery cooler 15 and through the coolant 14 are
collected by the second switching valve 20 to be sucked into the
second pump 12.
[0383] In this way, in the first mode, the intermediate-temperature
coolant cooled by the radiator 13 flows through the inverter cooler
16, the condenser 50, and the heater core 51, whereas the
low-temperature coolant cooled by the coolant cooler 14 flows
through the supercooler 60 and the battery cooler 15.
[0384] As a result, the inverter and the high-pressure refrigerant
of the condenser 50 are cooled by the intermediate-temperature
coolant, and the battery and the liquid-phase refrigerant of the
supercooler 60 are cooled by the low-temperature coolant.
[0385] When the battery is charged with the external power source,
the compressor 23 of the refrigeration cycle 22 is driven by power
supplied from the external power source. Thus, in the first mode,
the cold energy is stored in the battery using the power supplied
from the external power source.
[0386] In the first mode, the evaporator 55 exchanges heat between
the blast air into the vehicle interior and the low-pressure
refrigerant of the refrigeration cycle 22 to thereby cool the blast
air into the vehicle interior. In the first mode, the condenser 50
exchanges heat between the intermediate-temperature coolant and the
high-pressure refrigerant of the refrigeration cycle 22 to thereby
heat the intermediate-temperature coolant, whereas the heater core
51 exchanges heat between the blast air into the vehicle interior
and the intermediate-temperature coolant to thereby heat the blast
air into the vehicle interior.
[0387] Thus, the conditioned air at the desired temperature can be
made to adjust the temperature of air in the vehicle interior. For
example, when the battery is charged before a passenger rides on a
vehicle, pre-air conditioning can be carried out to perform air
conditioning of the vehicle interior before the passenger rides
on.
[0388] When the battery is not charged with the external power
source and the interior of the vehicle needs cooling, the
controller 40 performs the second mode shown in FIG. 26.
[0389] In the second mode, the controller 40 controls the electric
motor 30 for a switching valve such that the first and second
switching valves 19 and 20 are brought into the first state shown
in FIG. 26 to operate the first and second pumps 11 and 12 and the
compressor 23, thereby switching the electromagnetic valve 59 to
the closed state. That is, the second mode has the same states of
the first and second switching valves 19 and 20 as those in the
first mode, but differs from the first mode in that the
electromagnetic valve 59 is closed.
[0390] Thus, the low-pressure refrigerant of the refrigeration
cycle 22 does not flow through the coolant cooler 14, and as a
result the coolant is not cooled by the coolant cooler 14. However,
the coolant is cooled by the cold energy stored at the battery in
the battery cooler 15 in the first mode.
[0391] Since the low-temperature coolant cooled by the battery
cooler 15 flows through the supercooler 60, the liquid-phase
refrigerant (high-pressure refrigerant) is cooled by the
low-temperature coolant.
[0392] Thus, in the second mode, the cold energy stored in the
battery can be used to supercool the high-pressure refrigerant of
the refrigeration cycle 22, which can improve the efficiency of the
refrigeration cycle 22, thereby achieving the energy saving.
[0393] Note that in the second mode, the low-temperature coolant
may be cooled by the coolant cooler 14 with the electromagnetic
valve 59 opened.
[0394] When the battery is at a predetermined temperature (for
example, 40.degree. C.) or less, and thus does not need cooling,
and when the vehicle interior does not need to be heated, the
controller 40 performs the third mode shown in FIG. 27.
[0395] In the third mode, the controller 40 controls the electric
motor 30 for a switching valve such that the first and second
switching valves 19 and 20 are brought into the second state shown
in FIG. 27 to thereby operate the first and second pumps 11 and 12
and the compressor 23, thereby switching the electromagnetic valve
59 to the opened state.
[0396] Thus, the first switching valve 19 connects the inlet 19a
with the outlets 19c, and 19f, and also connects the inlet 19b with
the outlet 19d, thereby closing the outlet 19e. The second
switching valve 20 connects the inlets 20a and 20d with the outlet
20e, and also connects the inlet 20b with the outlet 20f, thereby
closing the inlet 20c.
[0397] Accordingly, a first coolant circuit (low-temperature
coolant circuit) is formed of the first pump 11, the coolant cooler
14, the inverter cooler 16, and the radiator 13, whereas a second
coolant circuit (intermediate-temperature coolant circuit) is
formed of the second pump 12, the condenser 50, and the heater core
51.
[0398] That is, as indicated by solid arrows in FIG. 27, the
coolant discharged from the first pump 11 is branched into the
coolant cooler 14, and the inverter cooler 16 by the first
switching valve 19 to flowing through the coolant cooler 14 and the
inverter cooler 16 in parallel. The coolants flowing through the
coolant cooler 14, and through the inverter cooler 16 are collected
by the second switching valve 20 to flow through the radiator 13,
thereby being sucked into the first pump 11.
[0399] On the other hand, as indicated by an alternate long and
short dashed arrow in FIG. 27, the coolant discharged from the
second pump 12 flows through the condenser 50 and the heater core
51 in series via the first switching valve 19, and is then sucked
into the second pump 12 via the second switching valve 20.
[0400] Thus, in the third mode, the low-temperature coolant cooled
by the coolant cooler 14 flows through the inverter cooler 16,
which can cool the inverter by the low-temperature coolant.
[0401] In this case, the battery is at a predetermined temperature
(for example, 40.degree. C.) or less, and thus does not need to be
cooled, so that the circulation of the coolant to the battery
cooler 15 is stopped.
[0402] In the third mode, the low-temperature coolant cooled by the
coolant cooler 14 flows through the radiator 13, allowing the
coolant to absorb heat from the outside air in the radiator 13.
Then, the coolant that has absorbed heat from the outside air in
the radiator 13 exchanges heat with the refrigerant of the
refrigeration cycle 22 in the coolant cooler 14 to dissipate heat
therefrom. Thus, in the coolant cooler 14, the refrigerant of the
refrigeration cycle 22 absorbs heat from the outside air via the
coolant.
[0403] The refrigerant which has absorbed heat from the outside air
in the coolant cooler 14 exchanges heat with the coolant of the
intermediate-temperature coolant circuit in the condenser 50,
whereby the coolant of the intermediate-temperature coolant circuit
is heated. The coolant of the intermediate-temperature circuit
heated by the condenser 50 exchanges heat with the blast air having
passed through the evaporator 55 in flowing through the heater core
51, thereby dissipating heat therefrom. Thus, the heater core 51
heats the blast air after having passed through the evaporator 55.
Accordingly, the fourth mode can achieve heat pump heating that
heats the vehicle interior by absorbing heat from the outside
air.
[0404] The blast air heated by the heater core 51 is a dried cool
air cooled and dehumidified by the low-pressure refrigerant of the
refrigeration cycle 22 in the evaporator 55. Thus, in the third
mode, the dehumidification heating can be performed.
[0405] Alternatively, when the temperature of the battery increases
in the third mode, the intermediate-temperature coolant or
low-temperature coolant may circulate into the battery cooler 15,
thereby cooling the battery.
[0406] In this embodiment, when the battery is charged with the
electric power supplied from the external power source, the
electromagnetic valve 59 is opened to allow the low-pressure
refrigerant of the refrigeration cycle to flow into the coolant
cooler 14, so that the coolant cooled by the coolant cooler 14
flows through the battery cooler 15 to thereby cool the battery.
Thus, the cold energy made by the refrigeration cycle 22 can be
stored in the battery.
[0407] After the battery is charged with the electric power
supplied from the external power source, the coolant flowing
through the battery cooler 15 flows through the supercooler 60, so
that the refrigerant flowing through the supercooler 60 can be
cooled by the cold energy stored in the battery, further improving
the efficiency of the refrigeration cycle 22. At this time, the
electromagnetic valve 59 is closed to prevent the low-pressure
refrigerant of the refrigeration cycle from flowing into the
coolant cooler 14, thereby decreasing a cooling load on the
refrigeration cycle 22.
[0408] Thus, for example, when the external power source cannot be
used during traveling of the vehicle, the cold energy stored in the
battery can be used for cooling the devices to be cooled, thereby
decreasing the power consumption.
[0409] In this embodiment, the supercooler 60 and the battery
cooler 15 are connected together in series, which can effectively
cool the coolant heated through the supercooler 60 with the cold
energy stored in the battery cooler 15 as compared to the case in
which the supercooler 60 and the battery cooler 15 are connected
together in parallel.
[0410] In this embodiment, the coolant cooler 14, the condenser 50,
and the supercooler 60 are integrated into one heat exchanger 52,
which can significantly improve the productivity as compared to the
case where the coolant cooler 14, the condenser 50, and the
supercooler 60 are formed of different heat exchangers.
[0411] Further, in this embodiment, the inlet 61e and outlet 61g
for the coolant of the coolant cooler 14 are disposed inside both
the ends 61q and 61r of the tank portions 61b and 61c in the tube
stacking direction, which can increase the flexibility in
connection of the pipes and arrangement of the heat exchangers as
compared to the case where the inlet 61e and outlet 61g for the
coolant are disposed at both ends 61q and 61r of the tank portions
61b and 61c in the tube stacking direction. The coolant cooler 14
does not allow the flow of coolant to make a U-turn, and thus can
reduce the loss of pressure of the coolant in the coolant cooler
14.
[0412] Likewise, the inlet 61i and outlet 61k for the coolant of
the condenser 50 are disposed inside both the ends 61q and 61r of
the tank portions 61b and 61c in the tube stacking direction, which
can increase the flexibility in connection of the pipes and
arrangement of the heat exchangers as compared to the case where
the inlet 61i and outlet 61k for the coolant are disposed at both
the ends 61q and 61r of the tank portions 61b and 61c in the tube
stacking direction. The condenser 50 does not allow the flow of
coolant to make a U-turn, and thus can reduce the loss of pressure
of the coolant in the condenser 50.
[0413] Likewise, the inlet 61n and outlet 61m for the coolant and
the outlet 61o for the refrigerant of the supercooler 60 are
disposed inside both the ends 61q and 61r of the tank portions 61b
and 61c in the tube stacking direction, which can increase the
flexibility in connection of the pipes and arrangement of the heat
exchangers as compared to the case where the inlet 61i and outlet
61k for the coolant and the outlet 610 for the refrigerant are
disposed at both the ends 61q and 61r of the tank portions 61b and
61c in the tube stacking direction. The condenser 50 does not allow
the flow of coolant and the flow of refrigerant to make the U-turn,
and thus can reduce the loss of pressure of the coolant in the
condenser 50.
Third Embodiment
[0414] In a third embodiment of the invention, as shown in FIG. 29,
an intake air cooler 65 (device to be cooled) is added to the
structure of the above second embodiment. The intake air cooler 65
is a heat exchanger that cools intake air by exchanging heat
between the coolant and the intake air at a high temperature
compressed by a supercharger for an engine. The intake air is
preferably cooled down to about 30.degree. C.
[0415] The coolant inlet side of the intake air cooler 65 is
connected to the outlet 19g of the first switching valve 19. The
coolant outlet side of the intake air cooler 65 is connected to the
inlet 20g of the second switching valve 20.
[0416] In this embodiment, the supercooler 60 is connected to
between the coolant outlet side of the coolant cooler 14 and the
inlet 20a of the second switching valve 20.
[0417] The first switching valve 19 is configured to be capable of
switching among three types of communication states between the
inlets 19a and 19b and the outlets 19c, 19d, 19e, 19f, and 19g. The
second switching valve 20 is also configured to be capable of
switching among three types of communication states between the
inlets 20a, 20b, 20c, 20d, and 20g and the outlets 20e, and
20f.
[0418] FIG. 30 shows the operation (first mode) of the cooling
system 10 when the first and second switching valves 19 and 20 are
switched to a first state.
[0419] In the first state, the first switching valve 19 connects
the inlet 19a with the outlets 19d, 19f, and 19g, and also connects
the inlet 19b with the outlets 19c and 19e. Thus, the first
switching valve 19 allows the coolant entering the inlet 19a to
flow out of the outlets 19d, 19f, and 19g as indicated by alternate
long and short dashed arrows in FIG. 30, and also allows the
coolant entering the inlet 19b to flow out of the outlets 19c and
19e as solid arrows in FIG. 30.
[0420] In the first state, the second switching valve 20 connects
the inlets 20b, 20d, and 20g with the outlet 20e, and also connects
the inlets 20a, and 20c with the outlet 20f. Thus, the second
switching valve 20 allows the coolant entering the inlets 20b, 20d,
and 20g to flow out of the outlet 20e as indicated by alternate
long and short dashed arrows in FIG. 30, and also allows the
coolant entering the inlets 20a and 20c to flow out of the outlet
20f as solid arrow in FIG. 30.
[0421] FIG. 31 shows the operation (second mode) of the cooling
system 10 when the first and second switching valves 19 and 20 are
switched to a second state.
[0422] In the second state, the first switching valve 19 connects
the inlet 19a with the outlet 19d, and also connects the inlet 19b
with the outlets 19c, 19e, 19f, and 19g. Thus, the first switching
valve 19 allows the coolant entering the inlet 19a to flow out of
the outlet 19d as indicated by an alternate long and short dashed
arrow in FIG. 31, and also allows the coolant entering the inlet
19b to flow out of the outlets 19c, 19e, 19f, and 19g as solid
arrows in FIG. 31.
[0423] In the second state, the second switching valve 20 connects
the inlet 20b with the outlet 20e and also connects the inlets 20a,
20c, 20d, and 20g with the outlet 20f. Thus, the second switching
valve 20 allows the coolant entering the inlet 20b to flow out of
the outlet 20e as indicated by an alternate long and short dashed
arrow in FIG. 31, and the coolant entering the inlets 20a, 20c,
20d, and 20g to flow out of the outlet 20f as a solid arrow in FIG.
31.
[0424] FIG. 32 shows the operation (third mode) of the cooling
system 10 when the first and second switching valves 19 and 20 are
switched to a third state.
[0425] In the third state, the first switching valve 19 connects
the inlet 19a with the outlets 19c and 19f, and also connects the
inlet 19b with the outlets 19d, 19e, and 19g. Thus, the first
switching valve 19 allows the coolant entering the inlet 19a to
flow out of the outlets 19c, and 19f as indicated by solid arrows
in FIG. 32, and also allows the coolant entering the inlet 19b to
flow out of the outlets 19d, 19e, and 19g as indicated by alternate
long and short dashed arrows in FIG. 32.
[0426] In the third state, the second switching valve 20 connects
the inlets 20a, and 20d with the outlet 20e, and also connects the
inlets 20b, 20c, and 20g with the outlet 20f. Thus, the second
switching valve 20 allows the coolant entering the inlets 20a and
20d to flow out of the outlet 20e as indicated by solid arrows in
FIG. 32, and also allows the coolant entering the inlets 20b, 20c,
and 20g to flow out of the outlet 20f as the alternate long and
short dashed arrow in FIG. 32.
[0427] Now, the operation of the above-mentioned structure will be
described. When the outside air temperature detected by the outside
air sensor 42 is more than 15.degree. C. and less than 40.degree.
C., the controller 40 performs the first mode shown in FIG. 30.
[0428] In the first mode, the controller 40 controls the electric
motor 30 for a switching valve such that the first and second
switching valves 19 and 20 are brought into the first state shown
in FIG. 30 to thereby operate the first and second pumps 11 and 12
and the compressor 23, thereby switching the electromagnetic valve
59 to the opened state.
[0429] Thus, the first switching valve 19 connects the inlet 19a
with the outlets 19d, 19f, and 19g, and also connects the inlet 19b
with the outlets 19c and 19e. The second switching valve 20
connects the inlets 20b, 20d, and 20g with the outlet 20e, and also
connects the inlets 20a and 20c with the outlet 20f.
[0430] Accordingly, the first coolant circuit
(intermediate-temperature coolant circuit) is formed of the first
pump 11, the inverter cooler 16, the condenser 50, the heater core
51, the intake air cooler 65, and the radiator 13, whereas the
second coolant circuit (low-temperature coolant circuit) is formed
of the second pump 12, the coolant cooler 14, the supercooler 60,
and the battery cooler 15.
[0431] That is, as indicated by alternate long and short dashed
arrows in FIG. 30, the coolant discharged from the first pump 11 is
branched into the inverter cooler 16, the condenser 50, and the
intake air cooler 65 by the first switching valve 19 to flow in
parallel through the inverter cooler 16, the condenser 50, and the
intake air cooler 65. The coolant flowing through the condenser 50
flows in series through the heater core 51. The coolants flowing
through the heater core 51, through the inverter cooler 16, and
through the intake air cooler 65 are collected by the second
switching valve 20 to flow through the radiator 13, thereby being
sucked into the first pump 11.
[0432] On the other hand, as indicated by solid arrows of FIG. 30,
the coolant discharged from the second pump 12 is branched into the
coolant cooler 14 and the battery cooler 15 by the first switching
valve 19 to flow in parallel through the coolant cooler 14 and the
battery cooler 15. The coolant flowing through the coolant cooler
14 flows in series through the supercooler 60. The coolants flowing
through the supercooler 60 and through the battery cooler 15 are
collected by the second switching valve 20 to be sucked into the
second pump 12.
[0433] In this way, in the first mode, the intermediate-temperature
coolant cooled by the radiator 13 flows through the inverter cooler
16, the condenser 50, the heater core 51, and the intake air cooler
65, whereas the low-temperature coolant cooled by the coolant
cooler 14 flows through the supercooler 60 and the battery cooler
15.
[0434] As a result, the inverter, the intake air, and the
high-pressure refrigerant of the condenser 50 are cooled by the
intermediate-temperature coolant, and the liquid-phase refrigerant
of the supercooler 60 and the battery are cooled by the
low-temperature coolant.
[0435] In the first mode, the evaporator 55 exchanges heat between
the blast air into the vehicle interior and the low-pressure
refrigerant of the refrigeration cycle 22 to thereby cool the blast
air into the vehicle interior. In the first mode, the condenser 50
exchanges heat between the intermediate-temperature coolant and the
high-pressure refrigerant of the refrigeration cycle 22 to thereby
heat the intermediate-temperature coolant, whereas the heater core
51 exchanges heat between the blast air into the vehicle interior
and the intermediate-temperature coolant to thereby heat the blast
air into the vehicle interior. Thus, the conditioned air at the
desired temperature can be made to adjust the temperature of air in
the vehicle interior.
[0436] When the outside air temperature detected by the outside air
sensor 42 is 40.degree. C. or higher, the controller 40 performs
the second mode shown in FIG. 31.
[0437] In the second mode, the controller 40 controls the electric
motor 30 for a switching valve such that the first and second
switching valves 19 and 20 are brought into the second state shown
in FIG. 31 to thereby operate the first and second pumps 11 and 12
and the compressor 23, thereby switching the electromagnetic valve
59 to the opened state.
[0438] Thus, the first switching valve 19 connects the inlet 19a
with the outlet 19d and also connects the inlet 19b with the
outlets 19c, 19e, 19f, and 19g. The second switching valve 20
connects the inlet 20b with the outlet 20e, and also connects the
inlets 20a, 20c, 20d, and 20g with the outlet 20f.
[0439] Accordingly, the first coolant circuit
(intermediate-temperature coolant circuit) is formed of the first
pump 11, the condenser 50, the heater core 51, and the radiator 13,
whereas the second coolant circuit (low-temperature coolant
circuit) is formed of the second pump 12, the coolant cooler 14,
the supercooler 60, the battery cooler 15, and the inverter cooler
16.
[0440] That is, as indicated by an alternate long and short dashed
arrow of FIG. 31, the coolant discharged from the first pump 11
flows through the condenser 50 and the heater core 51 in series via
the first switching valve 19, and is then sucked into the first
pump 11 via the second switching valve 20.
[0441] On the other hand, as indicated by solid arrows in FIG. 31,
the coolant discharged from the second pump 12 is branched into the
coolant cooler 14, the battery cooler 15, the inverter cooler 16,
and the intake air cooler 65 by the first switching valve 19. The
coolant flowing through the coolant cooler 14 flows in series
through the supercooler 60. The coolants flowing through the cooler
core 60, through the battery cooler 15, through the inverter cooler
16, and through the intake air cooler 65 are collected by the
second switching valve 20 to be sucked into the second pump 12.
[0442] In this way, in the second mode, the
intermediate-temperature coolant cooled by the radiator 13 flows
through the condenser 50, and the heater core 51, whereas the
low-temperature coolant cooled by the coolant cooler 14 flows
through the supercooler 60, the battery cooler 15, the inverter
cooler 16, and the intake air cooler 65.
[0443] As a result, the high-pressure refrigerant of the condenser
50 is cooled by the intermediate-temperature coolant, and the
liquid-phase refrigerant of the supercooler 60, the battery, the
inverter, and the intake air are cooled by the low-temperature
coolant.
[0444] In the second mode, the evaporator 55 exchanges heat between
the blast air into the vehicle interior and the low-pressure
refrigerant of the refrigeration cycle 22 to thereby cool the blast
air into the vehicle interior. In the second mode, the condenser 50
exchanges heat between the high-pressure refrigerant of the
refrigeration cycle 22 and the intermediate-temperature coolant to
thereby heat the intermediate-temperature coolant, whereas the
heater core 51 exchanges heat between the intermediate-temperature
coolant and the blast air into the vehicle interior to thereby heat
the blast air into the vehicle interior. Thus, the conditioned air
at the desired temperature can be made to adjust the temperature of
air in the vehicle interior.
[0445] Even in performing the first mode, under sudden
acceleration, such as upon startup, the low-temperature coolant is
allowed to flow through the intake air cooler 65, thereby cooling
the intake air with the low-temperature coolant in the same way as
the second mode. Thus, even though the intake air temperature is
increased due to an increase in supercharging pressure at the time
of sudden acceleration, the intake air can be sufficiently cooled
to improve the fuel efficiency.
[0446] When the outside air temperature detected by the outside air
sensor 42 is 0.degree. C. or lower, the controller 40 performs the
third mode shown in FIG. 32.
[0447] In the third mode, the controller 40 controls the electric
motor 30 for a switching valve such that the first and second
switching valves 19 and 20 are brought into the third state shown
in FIG. 32 to thereby operate the first and second pumps 11 and 12
and the compressor 23, thereby switching the electromagnetic valve
59 to the opened state.
[0448] Thus, the first switching valve 19 connects the inlet 19a
with the outlets 19c and 19f and also connects the inlet 19b with
the outlets 19d, 19e, and 19g. The second switching valve 20
connects the inlets 20a and 20d with the outlet 20e, and also
connects the inlets 20b, 20c, and 20g with the outlet 20f.
[0449] Accordingly, the first coolant circuit (low-temperature
coolant circuit) is formed of the first pump 11, the coolant cooler
14, the supercooler 60, the inverter cooler 16, and the radiator
13, whereas the second coolant circuit (intermediate-temperature
coolant circuit) is formed of the second pump 12, the battery
cooler 15, the condenser 50, the heater core 51, and the intake
cooler 65.
[0450] That is, as indicated by solid arrows of FIG. 32, the
coolant discharged from the first pump 11 is branched into the
coolant cooler 14, and the inverter cooler 16 by the first
switching valve 19. The coolant flowing through the coolant cooler
14 flows in series through the supercooler 60. The coolants flowing
through the supercooler 60 and through the inverter cooler 16 are
collected by the second switching valve 20 to thereby be sucked
into the first pump 11.
[0451] On the other hand, as indicated by alternate long and short
dashed arrows of FIG. 32, the coolant discharged from the second
pump 12 is branched into the battery cooler 15, the condenser 50,
and the intake air cooler 65 by the first switching valve 19. The
coolant flowing through the condenser 50 flows in series through
the heater core 51. The coolants flowing through the cooler core
51, through the battery cooler 15, and through the intake air
cooler 65 are collected by the second switching valve 20 to be
sucked into the second pump 12.
[0452] In the third mode, the low-temperature coolant cooled by the
coolant cooler 14 flows through the inverter cooler 16, which can
cool the inverter by the low-temperature coolant.
[0453] In the third mode, the low-temperature coolant cooled by the
coolant cooler 14 flows through the radiator 13, allowing the
coolant to absorb heat from the outside air in the radiator 13.
Then, the coolant that has absorbed heat from the outside air in
the radiator 13 exchanges heat with the refrigerant of the
refrigeration cycle 22 in the coolant cooler 14 to dissipate heat
therefrom. Thus, in the coolant cooler 14, the refrigerant of the
refrigeration cycle 22 absorbs heat from the outside air via the
coolant.
[0454] The refrigerant which has absorbed heat from the outside air
in the coolant cooler 14 exchanges heat with the coolant of the
intermediate-temperature coolant circuit in the condenser 50,
whereby the coolant of the intermediate-temperature coolant circuit
is heated. The coolant of the intermediate-temperature circuit
heated by the condenser 50 exchanges heat with the blast air having
passed through the evaporator 55 in flowing through the heater core
51, thereby dissipating heat therefrom. Thus, the heater core 51
heats the blast air after having passed through the evaporator 55.
Accordingly, the fourth mode can achieve heat pump heating that
heats the vehicle interior by absorbing heat from the outside
air.
[0455] The blast air heated by the heater core 51 is a dried cool
air cooled and dehumidified by the evaporator 55. Thus, in the
third mode, the dehumidification heating can be performed.
[0456] In the third mode, the intermediate-temperature coolant
heated by the condenser 50 flows through the battery cooler 15 and
the intake air cooler 65. Thus, the third mode can improve the
output of the battery by heating the battery, and promoting the
atomization of the fuel by heating the intake air, further
improving the fuel efficiency. In particular, at the cold start
when fuel is difficult to atomize due to the cold engine, the
promotion of the atomization of the fuel can improve the combustion
efficiency.
Fourth Embodiment
[0457] Although in the first embodiment, the radiator 13 is
connected between the outlet 20e of the second switching valve 20
and the suction side of the first pump 11, in a fourth embodiment,
as shown in FIG. 33, the radiator 13 is connected between the
outlet 19g of the first switching valve 19 and the inlet 20g of the
second switching valve 20.
[0458] The coolant inlet side of the radiator 13 is connected to
the outlet 19g of the first switching valve 19. The coolant outlet
side of the radiator 13 is connected to the inlet 20g of the second
switching valve 20.
[0459] The first switching valve 19 is configured to be capable of
switching among two types of communication states between the
inlets 19a and 19b and the outlets 19c, 19d, 19e, 19f, and 19g. The
second switching valve 20 is also configured to be capable of
switching among two types of communication states between the
inlets 20a, 20b, 20c, 20d, and 20g and the outlets 20e, and
20f.
[0460] FIG. 34 shows the operation (first mode) of the cooling
system 10 when the first and second switching valves 19 and 20 are
switched to a first state.
[0461] In the first state, the first switching valve 19 connects
the inlet 19a with the outlets 19d and 19e, and also connects the
inlet 19b with the outlets 19c, 19f, and 19g. Thus, the first
switching valve 19 allows the coolant entering the inlet 19a to
flow out of the outlets 19d and 19e as indicated by an alternate
long and short dashed arrow in FIG. 34, and also allows the coolant
entering the inlet 19b to flow out of the outlets 19c, 19f, and 19g
as solid arrows in FIG. 34.
[0462] In the first state, the second switching valve 20 connects
the inlets 20b, and 20c with the outlet 20e and also connects the
inlets 20a, 20d, and 20g with the outlet 20f. Thus, the second
switching valve 20 allows the coolant entering the inlets 20b and
20c to flow out of the outlet 20e as indicated by alternate long
and short dashed arrows in FIG. 34, and also allows the coolant
entering the inlets 20a, 20d, and 20g to flow out of the outlet 20f
as solid arrows in FIG. 30.
[0463] FIG. 35 shows the operation (second mode) of the cooling
system 10 when the first and second switching valves 19 and 20 are
switched to a second state.
[0464] In the second state, the first switching valve 19 connects
the inlet 19a with the outlet 19d, and also connects the inlet 19b
with the outlets 19c, 19e, and 19f, thereby closing the outlet 19g.
Thus, the first switching valve 19 allows the coolant entering the
inlet 19a to flow out of the outlet 19d as indicated by an
alternate long and short dashed arrow in FIG. 35, and also allows
the coolant entering the inlet 19b to flow out of the outlets 19c,
19e, and 19f as indicated by solid arrows in FIG. 35, thereby
preventing the coolant from flowing out of the outlet 19g.
[0465] In the second state, the second switching valve 20 connects
the inlet 20b with the outlet 20e and also connects the inlets 20a,
20c, and 20d with the outlet 20f, thereby closing the inlet 20g.
Thus, the second switching valve 20 allows the coolant entering the
inlets 20b to flow out of the outlet 20e as indicated by an
alternate long and short dashed arrow in FIG. 35, and also allows
the coolant entering the inlets 20a, 20c, and 20d to flow out of
the outlet 20f as indicated by solid arrows in FIG. 35, thereby
preventing the coolant from flowing out of the inlet 20g.
[0466] When the battery is charged with the power supplied from the
external power supply at a very low temperature of the outside air
(for example, at 0.degree. C.) in winter, the controller 40
performs the first mode shown in FIG. 34.
[0467] In the first mode, the controller 40 controls the electric
motor 30 for a switching valve such that the first and second
switching valves 19 and 20 are brought into the first state shown
in FIG. 34 to thereby operate the first and second pumps 11 and 12
and the compressor 23.
[0468] Thus, the first switching valve 19 connects the inlet 19a
with the outlets 19d and 19e and also connects the inlet 19b with
the outlets 19c, 19f, and 19g. The second switching valve 20
connects the inlets 20b and 20c with the outlet 20e, and also
connects the inlets 20a, 20d, and 20g with the outlet 20f.
[0469] Accordingly, a first coolant circuit
(intermediate-temperature coolant circuit) is formed of the first
pump 11, the battery cooler 15, the condenser 50, and the heater
core 51, whereas a second coolant circuit (low-temperature coolant
circuit) is formed of the second pump 12, the coolant cooler 14,
the cooler core 18 the inverter cooler 16, and the heater core
13.
[0470] That is, as indicated by alternate long and short dashed
arrows in FIG. 34, the coolant discharged from the first pump 11 is
branched into the inverter cooler 15 and the condenser 50 by the
first switching valve 19 to flow in parallel through the inverter
cooler 15 and the condenser 50. The coolant flowing through the
condenser 50 flows in series through the heater core 51. The
coolants flowing through the heater core 51 and through the
inverter cooler 15 are collected by the second switching valve 20
to be sucked into the first pump 11.
[0471] On the other hand, as indicated by solid arrows in FIG. 34,
the coolant discharged from the second pump 12 is branched into the
coolant cooler 14, the inverter cooler 16, and the radiator 13 by
the first switching valve 19. The coolant flowing through the
coolant cooler 14 flows in series through the cooler core 18. The
coolants flowing through the cooler core 18, through the inverter
cooler 16, and through the radiator 13 are collected by the second
switching valve 20 to be sucked into the second pump 12.
[0472] In the first mode, the low-temperature coolant cooled by the
coolant cooler 14 flows through the inverter cooler 16 and the
cooler core 18, which can cool the inverter and the blast air into
the vehicle interior by the low-temperature coolant.
[0473] In the first mode, the low-temperature coolant cooled by the
coolant cooler 14 flows through the radiator 13, allowing the
coolant to absorb heat from the outside air in the radiator 13.
Then, the coolant that has absorbed heat from the outside air in
the radiator 13 exchanges heat with the refrigerant of the
refrigeration cycle 22 in the coolant cooler 14 to dissipate heat
therefrom. Thus, in the coolant cooler 14, the refrigerant of the
refrigeration cycle 22 absorbs heat from the outside air via the
coolant.
[0474] The refrigerant which has absorbed heat from the outside air
in the coolant cooler 14 exchanges heat with the coolant of the
intermediate-temperature coolant circuit in the condenser 50,
whereby the coolant of the intermediate-temperature coolant circuit
is heated. The coolant of the intermediate-temperature circuit
heated by the condenser 50 exchanges heat with the blast air having
passed through the cooler core 18 in flowing through the heater
core 51, thereby dissipating heat therefrom. Thus, the heater core
51 heats the blast air having passed through the cooler core 18.
Accordingly, the fourth mode can achieve heat pump heating that
heats the vehicle interior by absorbing heat from the outside
air.
[0475] The blast air heated by the heater core 51 is a dried cool
air which is cooled and dehumidified by the cooler core 18. Thus,
in the first mode, the dehumidification heating can be
performed.
[0476] For example, when the battery is charged before a passenger
rides on a vehicle, pre-air conditioning can be carried out to
perform air conditioning of the vehicle interior before the
passenger rides on.
[0477] Further, in the first mode, the intermediate-temperature
coolant heated by the condenser 50 flows through the battery cooler
15, so that the warm energy can be stored in the battery by heating
the battery. In this embodiment, in the first mode, the battery is
heated up to about 40.degree. C.
[0478] When the charging of the battery with the power from the
external power source is completed and the vehicle starts
traveling, the controller 40 performs the second mode shown in FIG.
35.
[0479] In the second mode, the controller 40 controls the electric
motor 30 for a switching valve such that the first and second
switching valves 19 and 20 are brought into the second state shown
in FIG. 35 to thereby operate the first and second pumps 11 and 12
and the compressor 23.
[0480] Thus, the first switching valve 19 connects the inlet 19a
with the outlet 19d, and also connects the inlet 19b with the
outlets 19c, 19e, and 19f, thereby closing the outlet 19g. The
second switching valve 20 connects the inlet 20b with the outlet
20e, and also connects the inlets 20a, 20c, and 20d with the outlet
20f, thereby closing the inlet 20g.
[0481] Accordingly, the first coolant circuit
(intermediate-temperature coolant circuit) is formed of the first
pump 11, the condenser 50, and the heater core 51, whereas the
second coolant circuit (low-temperature coolant circuit) is formed
of the second pump 12, the coolant cooler 14, the cooler core 18,
the battery cooler 15, and the inverter cooler 16, thus stopping of
circulation of the coolant toward the radiator 13.
[0482] That is, as indicated by an alternate long and short dashed
arrow of FIG. 35, the coolant discharged from the first pump 11
flows through the condenser 50 and the heater core 51 in series via
the first switching valve 19, and is then sucked into the first
pump 11 via the second switching valve 20.
[0483] On the other hand, as indicated by solid arrows in FIG. 35,
the coolant discharged from the second pump 12 is branched into the
coolant cooler 14, the battery cooler 15, and the inverter cooler
16 by the first switching valve 19. The coolant flowing through the
coolant cooler 14 flows in series through the cooler core 18. The
coolants flowing through the cooler core 18, through the battery
cooler 15, and through the inverter cooler 16 are collected by the
second switching valve 20 to be sucked into the second pump 12.
[0484] In the second mode, the low-temperature coolant cooled by
the coolant cooler 14 flows through the battery cooler 15, allowing
the low-temperature coolant to absorb heat from the battery in the
radiator 15. Then, the coolant which has absorbed heat from the
battery in the battery cooler 15 exchanges heat with the
refrigerant of the refrigeration cycle 22 in the coolant cooler 14
to dissipate heat therefrom. Thus, in the coolant cooler 14, the
refrigerant of the refrigeration cycle 22 absorbs heat from the
battery via the coolant.
[0485] The refrigerant which has absorbed heat from the battery in
the coolant cooler 14 exchanges heat with the coolant of the
intermediate-temperature coolant circuit in the condenser 50,
thereby heating the coolant of the intermediate-temperature coolant
circuit. The coolant of the intermediate-temperature circuit heated
by the condenser 50 exchanges heat with the blast air having passed
through the cooler core 18 in flowing through the heater core 51,
thereby dissipating heat therefrom. Thus, the heater core 51 heats
the blast air having passed through the cooler core 18.
Accordingly, the second mode can achieve heat pump heating that
heats the vehicle interior by absorbing heat from the battery.
[0486] The blast air heated by the heater core 51 is a dried cool
air which is cooled and dehumidified by the cooler core 18. Thus,
in the second mode, the dehumidification heating can be
performed.
[0487] In this example, in the first mode, the battery is heated up
to about 40.degree. C., and hence in the second mode, the heat pump
can be achieved by drawing heat from the battery at the 40.degree.
C. Thus, this example can operate the thermal management system at
a higher temperature than the case where the low-pressure
refrigerant of the refrigeration cycle 22 absorbs heat from the
outside air (for example, 0.degree. C.), thereby improving the
operating efficiency of the heat pump.
[0488] In the second mode, the coolant does not circulate through
the radiator 13, and the radiator 13 does not absorb heat from
outside air, which can prevent the frost formation of the radiator
13.
Fifth Embodiment
[0489] Although in the above respective embodiments, the devices to
be cooled include the coolant cooler 14, the battery cooler 15, the
inverter cooler 16, the exhaust gas cooler 17, the cooler core 18,
the condenser 50, and the intake air cooler 65 by way of example,
in a fifth embodiment, as shown in FIG. 36, the devices to be
cooled include the intake air cooler 65, a fuel cooler 66, and a
vehicle-mounted electronic device cooler 67.
[0490] The fuel cooler 66 is a heat exchanger for cooling fuel by
exchanging heat between the fuel supplied to the engine and the
coolant. The vehicle-mounted electronic device cooler 67 is a heat
exchanger for cooling a vehicle-mounted electronic device by
exchanging heat between the vehicle-mounted electronic device and
the coolant. In this way, various devices can be used as the
devices to be cooled.
[0491] Like this embodiment, the condenser 50 may be connected to
between the discharge side of the first pump 11 and the inlet 19a
of the first switching valve 19.
Sixth Embodiment
[0492] Although in the above second embodiment, the outlet 61g and
inlet 61n for the coolant are formed in parts constituting the
coolant cooler 14 and the supercooler 60 of the tank portion 61c of
the heat exchanger 61, in a sixth embodiment, as shown in FIG. 37,
the outlet 61g and inlet 61n for the coolant are removed, and a
hole 61p for allowing the refrigerant to flow therethrough is
formed in a part of the partition portion 61d that partitions the
internal space of the tank portion 61c into a tank space for the
coolant cooler 14, and another tank space for the supercooler
60.
[0493] Thus, in the coolant cooler 14, the coolant flows from the
inlet 61e into the tank portion 61b, and is then distributed to the
tubes for the coolant by the tank portion 61b. The coolants after
having passed through the tubes for the coolant are collected into
the tank portion 61c to flow from the hole 61p of the partition
portion 61d into the supercooler 60.
[0494] In the supercooler 60, the coolant flows into the tank
portion 61c through the hole 61p of the partition portion 61d, and
is then distributed to the tubes for the coolant by the tank
portion 61c. The coolants after having passed through the tubes for
the coolant are collected into the tank portion 61b to flow from
the outlet 61m.
[0495] This embodiment can remove the outlet 61g and inlet 61n for
the coolant with respect to the heat exchanger 61 of the second
embodiment, and thus can simplify the connection structure of the
coolant pipes.
Seventh Embodiment
[0496] Although in the sixth embodiment, the coolant cooler 14, the
condenser 50, and the supercooler 60 are included in one heat
exchanger 61, in a seventh embodiment, as shown in FIG. 38, the
coolant cooler 14, the condenser 50, and the expansion valve 25 are
integrated together.
[0497] The coolant cooler 14 is composed of the tank-and-tube type
heat exchanger, and includes a heat exchanger core (second heat
exchanging portion) 14a, and tank portions 14b and 14c. The heat
exchanger core 14a includes a plurality of tubes through which the
coolant and the refrigerant flow independently. The tubes are
stacked on each other in parallel. The tank portions 14b and 14c
are disposed on both ends of the tubes to distribute and collect
the coolant and refrigerant for the tubes.
[0498] Respective members constituting the heat exchanger core 14a,
and the tank portions 14b and 14c are formed of metal (for example,
an aluminum alloy), and bonded together by brazing.
[0499] The condenser 50 is composed of the tank-and-tube type heat
exchanger, and includes a heat exchanger core (first heat
exchanging portion) 50a, and tank portions 50b and 50c. The heat
exchanger core 50a includes a plurality of tubes through which the
coolant and the refrigerant flow independently. The tubes are
stacked on each other in parallel. The tank portions 50b and 50c
are disposed on both ends of the tubes to distribute and collect
the coolant and refrigerant for the tubes.
[0500] Respective members constituting the heat exchanger core 50a,
and the tank portions 50b and 50c are formed of metal (for example,
an aluminum alloy), and bonded together by brazing.
[0501] The coolant cooler 14 and the condenser 24 are disposed in
parallel in the stacking direction of tubes (in the left-right
direction of FIG. 38). Specifically, the expansion valve 25 is
fixed while being sandwiched between the coolant cooler 14 and the
condenser 24.
[0502] The expansion valve 25 is a thermal expansion valve whose
valve opening degree is adjusted by a mechanical system such that a
degree of superheat of the refrigerant flowing from the coolant
cooler 14 is in a predetermined range. The expansion valve 25 has a
temperature sensing portion 25a for sensing the superheat degree of
the refrigerant on the outlet side of the coolant cooler 14.
[0503] One tank portion 14c of the coolant cooler 14 is provided
with an inlet 14e for the coolant and an outlet 14f for the
refrigerant. The outlet 14f for the refrigerant is superimposed
over the refrigerant inlet of the temperature sensing portion 25a
of the expansion valve 25.
[0504] The other tank portion 14b of the coolant cooler 14 is
provided with an outlet 14g for the coolant and an inlet 14h for
the refrigerant. The inlet 14h for the refrigerant is superimposed
over the refrigerant outlet of the expansion valve 25.
[0505] Thus, in the coolant cooler 14, the coolant flows from the
inlet 14e into the tank portion 14c, and is then distributed to the
tubes for the coolant by the tank portion 14c. The coolants after
having passed through the tubes for the coolant are collected into
the tank portion 14b to flow from the outlet 14g.
[0506] In the coolant cooler 14, the refrigerant decompressed by
the expansion valve 25 flows from the inlet 14h into the tank
portion 14b, and is then distributed to the tubes for the
refrigerant in the tank portion 14b. The refrigerants having passed
through the tubes for the refrigerant are collected into the tank
portion 14c to flow from the outlet 14f into the temperature
sensing portion 25a of the expansion valve 25. The temperature
sensing portion 25a of the expansion valve 25 is provided with an
outlet 25b for the refrigerant.
[0507] The inlet 14e and outlet 14g for the coolant of the coolant
cooler 14 are disposed between both ends of each of tank portions
14b and 14c in the tube stacking direction (both ends in the
left-right direction of FIG. 38). Thus, the coolant cooler 14 does
not allow the flow of coolant to make a U-turn.
[0508] The inlet 14e and outlet 14g are oriented in the direction
perpendicular to the tube stacking direction. In an example shown
in FIG. 38, the inlet 14e and outlet 14g are oriented in the
direction parallel to the tubes for the refrigerant and for the
coolant.
[0509] One tank portion 50b of the condenser 50 is provided with an
inlet 50e for the coolant and an outlet 50f for the refrigerant.
The outlet 50b for the refrigerant is superimposed over the
refrigerant inlet of the expansion valve 25. One other tank portion
50c of the condenser 50 is provided with an outlet 50g for the
coolant and an inlet 50h for the refrigerant.
[0510] Thus, in the condenser 50, the coolant flows from the inlet
50e into the tank portion 50b, and is then distributed to the tubes
for the coolant by the tank portion 50b. The coolants after having
passed through the tubes for the coolant are collected into the
tank portion 50c to flow from the outlet 50g.
[0511] In the condenser 50, the refrigerant flows from the inlet
50h into the tank portion 50c, and is then distributed to the tubes
for the refrigerant by the tank portion 50c. The coolants after
having passed through the tubes for the refrigerant are collected
into the tank portion 50b to flow from the outlet 50f into the
expansion valve 25. The refrigerant flowing from the outlet 50f
into the expansion valve 25 is decompressed by the expansion valve
25 to flow into the coolant cooler 14.
[0512] The inlet 50e and outlet 50g for the coolant of the
condenser 50 are disposed between both ends of tank portions 50b
and 50c in the tube stacking direction (both ends in the left-right
direction of FIG. 38). Thus, the condenser 50 does not allow the
flow of coolant to make a U-turn.
[0513] The inlet 50e and outlet 50g are oriented in the direction
perpendicular to the tube stacking direction. In the example shown
in FIG. 38, the inlet 50e and outlet 50g are oriented in the
direction parallel to the tubes for the refrigerant and for the
coolant.
[0514] Further, in this embodiment, the inlet 14e and outlet 14g
for the coolant of the coolant cooler 14 are disposed between both
ends (both ends in the left-right direction of FIG. 38) of each of
the tank portions 14b and 14c in the tube stacking direction, which
can increase the flexibility in connection of the pipes and
arrangement of the heat exchangers as compared to the case where
the inlet 14e and outlet 14g for the coolant are disposed at both
ends of each of the tank portions 14b and 14c in the tube stacking
direction. The coolant cooler 14 does not allow the flow of coolant
to make a U-turn, and thus can reduce the loss of pressure of the
coolant in the coolant cooler 14.
[0515] Likewise, the inlet 50e and outlet 50g for the coolant of
the condenser 50 are disposed between both ends (both ends in the
left-right direction of FIG. 38) of each of the tank portions 50b
and 50c in the tube stacking direction, which can increase the
flexibility in connection of the pipes and arrangement of the heat
exchangers as compared to the case where the inlet 50e and outlet
50g for the coolant are disposed at both ends of each of the tank
portions 50b and 50c in the tube stacking direction. The condenser
50 does not allow the flow of coolant to make a U-turn, and thus
can reduce the loss of pressure of the coolant in the condenser
50.
[0516] This embodiment does not need any refrigerant pipe between
the coolant cooler 14 and the expansion valve 25, and between the
condenser 50 and the expansion valve 25, and thus can simplify the
connection structure between the refrigerant pipes.
[0517] A first tank space 50i for the refrigerant in the internal
space of the tank portion 50b of the condenser 50 that causes the
refrigerant to flow into the expansion valve 25 is superimposed
over a second tank space 14i for the refrigerant in the tank
portion 14b of the coolant cooler 14 that causes the refrigerant
flowing out of the expansion valve 25 to flow thereinto as viewed
from the tube stacking direction. Thus, a common part or component
can be shared between the condenser 50 and the coolant cooler
14.
[0518] The first tank space 50i for the refrigerant, a
decompression flow path 25c of the expansion valve 25, and the
second tank space 14i for the refrigerant are linearly disposed
side by side in the tube stacking direction. Thus, the structure of
the coolant cooler 14, condenser 50, and expansion valve 25 can be
simplified. The decompression flow path 25c of the expansion valve
25 is a flow path through which the refrigerant flowing from the
condenser 50 is decompressed to flow into the coolant cooler
14.
Second Reference Example
[0519] Although in the first reference example, the operating mode
is switched according to the outside air temperature detected by
the outside air sensor 42, in a second reference embodiment, the
operating mode is switched according to the temperature of the
inverter and the temperature of the battery.
[0520] The first switching valve 19 is configured to be capable of
switching among four types of communication states between the
inlets 19a and 19b and the outlets 19c, 19d, 19e, and 19f. The
second switching valve 20 is also configured to be capable of
switching among four types of communication states between the
inlets 20a, 20b, 20c, and 20d and the outlets 20e, and 20f.
[0521] FIG. 39 shows the operation (first mode) of the cooling
system 10 when the first and second switching valves 19 and 20 are
switched to a first state.
[0522] In the first state, the first switching valve 19 closes the
inlet 19a, and connects the inlet 19b with the outlet 19c, 19d,
19e, and 19f. Thus, the first switching valve 19 does not allow the
coolant to flow into the inlet 19a, but allows the coolant entering
the inlet 19b to flow out of the outlets 19c, 19d, 19e, and 19f as
indicated by solid arrows in FIG. 39.
[0523] In the first state, the second switching valve 20 closes the
outlet 20e, and connects the inlets 20a, 20b, 20c, and 20d with the
outlet 20f. Thus, the second switching valve 20 does not allow the
coolant to flow from the outlet 20e, but allows the coolant
entering the inlets 20a, 20b, 20c, and 20d to flow out of the
outlet 20f as indicated by solid arrows of FIG. 39.
[0524] FIG. 40 shows the operation (second mode) of the cooling
system 10 when the first and second switching valves 19 and 20 are
switched to a second state.
[0525] In the second state, the first switching valve 19 connects
the inlet 19a with the outlet 19d, and also connects the inlet 19b
with the outlets 19c, 19e, and 19f. Thus, the first switching valve
19 allows the coolant entering the inlet 19a to flow out of the
outlet 19d as indicated by an alternate long and short dashed arrow
in FIG. 40, and also allows the coolant entering the inlet 19b to
flow out of the outlets 19c, 19e, and 19f as solid arrows in FIG.
40.
[0526] In the second state, the second switching valve 20 connects
the inlets 20a, 20c, and 20d with the outlet 20f, and also connects
the inlet 20b with the outlet 20e. Thus, the second switching valve
20 allows the coolant entering the inlet 20b to flow out of the
outlet 20e as indicated by an alternate long and short dashed arrow
in FIG. 40, and also allows the coolant entering the inlets 20a,
20c, and 20d to flow out of the outlet 20f as indicated by a solid
arrow in FIG. 40.
[0527] FIG. 41 shows the operation (third mode) of the cooling
system 10 when the first and second switching valves 19 and 20 are
switched to a third state.
[0528] In the third state, the first switching valve 19 connects
the inlet 19a with the outlets 19d and 19e, and also connects the
inlet 19b with the outlets 19c, and 19f. Thus, the first switching
valve 19 allows the coolant entering the inlet 19a to flow out of
the outlets 19d and 19e as indicated by alternate long and short
dashed arrows in FIG. 41, and also allows the coolant entering the
inlet 19b to flow from the outlets 19c and 19f as indicated by
solid arrows in FIG. 41.
[0529] In the third state, the second switching valve 20 connects
the inlets 20a, and 20d with the outlet 20f, and also connects the
inlets 20b and 20c with the outlet 20e. Thus, the second switching
valve 20 allows the coolant entering the inlets 20b and 20c to flow
out of the outlet 20e as indicated by alternate long and short
dashed arrows in FIG. 41, and also allows coolant entering the
inlets 20a and 20d to flow out of the outlet 20f as a solid arrow
in FIG. 41.
[0530] FIG. 42 shows the operation (fourth mode) of the cooling
system 10 when the first and second switching valves 19 and 20 are
switched to a fourth state.
[0531] In the fourth state, the first switching valve 19 connects
the inlet 19a with the outlet 19d, and also connects the inlet 19b
with the outlets 19e and 19f, thereby closing the outlet 19c. Thus,
the first switching valve 19 allows the coolant entering the inlet
19a to flow out of the outlet 19d as indicated by an alternate long
and short dashed arrow of FIG. 42, and also allows the coolant
entering the inlet 19b to flow out of the outlets 19e and 19f as
indicated by solid arrows of FIG. 42, thereby preventing the
coolant from flowing out of the outlet 19c.
[0532] In the fourth state, the second switching valve 20 connects
the inlets 20c and 20d with the outlet 20f and also connects the
inlet 20b with the outlet 20e, thereby closing the inlet 20a. Thus,
the second switching valve 20 allows the coolant entering the
inlets 20b to flow out of the outlet 20e as indicated by an
alternate long and short dashed arrow of FIG. 42, and also allows
the coolant entering the inlets 20c, and 20d to flow out of the
outlet 20f as indicated by solid arrows of FIG. 42, thereby
preventing the coolant from entering the inlet 20a.
[0533] Next, an electric controller of the cooling system 10 will
be described with reference to FIG. 43. The electric controller of
the cooling system 10 has the structure, in addition to the
above-mentioned structure of the first reference example, in which
detection signals from an inverter temperature sensor 45 and a
battery temperature sensor 46 are input to the input side of the
controller 40.
[0534] The inverter temperature sensor 45 is an inverter
temperature detector for detecting the temperature of the inverter.
For example, the inverter temperature sensor 45 may detect the
temperature of coolant flowing from the inverter cooler 16. The
battery temperature sensor 46 is a battery temperature detector for
detecting the temperature of the battery. For example, the battery
temperature sensor 46 may detect the temperature of coolant flowing
from the battery cooler 15.
[0535] A control process executed by the controller 40 of this
embodiment will be described with reference to FIG. 44. The
controller 40 executes a computer program according to a flowchart
of FIG. 44.
[0536] First, in step S200, it is determined whether an inverter
temperature Tiny detected by the inverter temperature sensor 45
exceeds 60.degree. C.
[0537] When the inverter temperature Tiny is determined not to
exceed 60.degree. C., the priority of cooling of the inverter is
determined not to be high, and the operation proceeds to step S210,
in which the first mode shown in FIG. 39 is performed.
[0538] In the first mode, the controller 40 controls the electric
motor 30 for a switching valve such that the first and second
switching valves 19 and 20 are brought into the first state shown
in FIG. 39, thereby operating the second pump 12 and the compressor
23, and stopping the first pump 11.
[0539] Thus, the first switching valve 19 closes the inlet 19a, and
connects the inlet 19b with the outlets 19c, 19d, 19e, and 19f. The
second switching valve 20 connects the inlets 20a, 20b, 20c, and
20d with the outlet 20f, and closes the outlet 20e.
[0540] Thus, the low-temperature coolant circuit is formed of the
second pump 12, the coolant cooler 14, the battery cooler 15, the
inverter cooler 16, the exhaust gas cooler 17, and the cooler core
18, and the intermediate-temperature coolant circuit is not
formed.
[0541] That is, as indicated by solid arrows of FIG. 39, the
coolant discharged from the second pump 12 flows through the
coolant cooler 14, and is branched by the first switching valve 19
into the battery cooler 15, the inverter cooler 16, the exhaust gas
cooler 17, and the cooler core 18. Then, the coolants flowing in
parallel through the battery cooler 15, the inverter cooler 16, the
exhaust gas cooler 17, and the cooler core 18 are collected into
the second switching valve 20 to be sucked into the second pump
12.
[0542] In contrast, as indicated by a dashed arrow of FIG. 39, the
coolant is not discharged from the first pump 11, and does not flow
through the radiator 13.
[0543] In this way, in the first mode, the low-temperature coolant
cooled by the coolant cooler 14 flows through the battery cooler
15, the inverter cooler 16, the exhaust gas cooler 17, and the
cooler core 18. As a result, the battery, the inverter, the exhaust
gas, and the blast air into the vehicle interior are cooled by the
low-temperature coolant.
[0544] When the inverter temperature Tiny is determined to exceed
60.degree. C. in step S200, the priority of cooling of the inverter
is determined to be high, and then the operation proceeds to step
S220. In step S220, it is determined whether the inverter
temperature Tiny is less than 70.degree. C. or not.
[0545] When the inverter temperature Tiny is determined to be
70.degree. C. or more, the inverter is considered to be at an
abnormal high temperature, and the operation proceeds to step S230,
in which a warning light is lit up. Thus, a passenger can be
informed that the inverter is at the abnormal high temperature.
[0546] When the inverter temperature Tiny is determined to be less
than 70.degree. C., the inverter is considered not to be at an
abnormal high temperature, and the operation proceeds to step S240,
in which the warning light is turned off. Thus, a passenger can be
informed that the inverter is not at the abnormal high
temperature.
[0547] In step S250 following steps S230 and S240, it is determined
whether or not the coolant of the intermediate-temperature coolant
circuit (intermediate-temperature coolant) circulates through the
exhaust gas cooler 17. Specifically, whether or not the coolant of
the intermediate-temperature coolant circuit
(intermediate-temperature coolant) circulates through the exhaust
gas cooler 17 is determined based on the operating states of the
first and second switching valves 19 and 20.
[0548] When the intermediate-temperature coolant is determined not
to circulate through the exhaust gas cooler 17, the operation
proceeds to step S260 so as to reduce the cooling capacity of the
exhaust gas, in which the second mode shown in FIG. 40 is
performed.
[0549] In the second mode, the controller 40 controls the electric
motor 30 for a switching valve such that the first and second
switching valves 19 and 20 are brought into the second state shown
in FIG. 40 to thereby operate the first and second pumps 11 and 12
and the compressor 23.
[0550] Thus, the first switching valve 19 connects the inlet 19a
with the outlet 19d and also connects the inlet 19b with the
outlets 19c, 19e, and 19f. The second switching valve 20 connects
the inlets 20a, 20c, and 20d with the outlet 20f, and also connects
the inlet 20b with the outlet 20e.
[0551] Accordingly, an intermediate-temperature coolant circuit is
formed of the first pump 11, the exhaust gas cooler 17, and the
radiator 13, whereas a low-temperature coolant circuit is formed of
the second pump 12, the coolant cooler 14, the battery cooler 15,
the inverter cooler 16, and the cooler core 18.
[0552] That is, as indicated by an alternate long and short dashed
arrow of FIG. 40, the coolant discharged from the first pump 11
flows through the exhaust gas cooler 17 via the first switching
valve 19, and then through the radiator 13 via the second switching
valve 20, thereby being sucked into the first pump 11.
[0553] On the other hand, as indicated by solid arrows in FIG. 40,
the coolant discharged from the second pump 12 flows through the
coolant cooler 14 to be branched into the battery cooler 15, the
inverter cooler 16, and the cooler core 18 by the first switching
valve 19. The coolants flowing in parallel through the battery
cooler 15, the inverter cooler 16, and the cooler core 18 are
collected into the second switching valve 20 to be sucked into the
second pump 12.
[0554] In this way, in the second mode, the
intermediate-temperature coolant cooled by the radiator 13 flows
through the exhaust gas cooler 17, whereas the low-temperature
coolant cooled by the coolant cooler 14 flows through the battery
cooler 15, the inverter cooler 16, and the cooler core 18. As a
result, the exhaust gas is cooled by the intermediate-temperature
coolant, and the battery, the inverter, and the blast air into the
vehicle interior are cooled by the low-temperature coolant.
[0555] Thus, the cooling capacity of the inverter can be improved
as compared to that in the first mode in which the exhaust gas can
also be cooled by the low-temperature coolant.
[0556] When the intermediate-temperature coolant is determined to
circulate through the exhaust gas cooler 17 in step S250, the
operation proceeds to step S270. In step S270, it is determined
whether a battery temperature Tbatt detected by the battery
temperature sensor 46 exceeds 50.degree. C. or not.
[0557] When the battery temperature Tbatt is determined not to
exceed 50.degree. C., the priority of cooling of the battery is
determined not to be high, and the operation proceeds to step S280,
in which the third mode shown in FIG. 41 is performed.
[0558] In the third mode, the controller 40 controls the electric
motor 30 for a switching valve such that the first and second
switching valves 19 and 20 are brought into the third state shown
in FIG. 41 to thereby operate the first and second pumps 11 and 12
and the compressor 23.
[0559] Thus, the first switching valve 19 connects the inlet 19a
with the outlets 19d, and 19e, and also connects the inlet 19b with
the outlets 19c and 19f. The second switching valve 20 connects the
inlets 20a and 20d with the outlet 20f, and also connects the
inlets 20b and 20c with the outlet 20e.
[0560] Accordingly, an intermediate-temperature coolant circuit is
formed of the first pump 11, the battery cooler 15, the exhaust gas
cooler 17, and the radiator 13, whereas a low-temperature coolant
circuit is formed of the second pump 12, the coolant cooler 14, the
inverter cooler 16, and the cooler core 18.
[0561] That is, as indicated by alternate long and short dashed
arrows in FIG. 41, the coolant discharged from the first pump 11 is
branched by the first switching valve 19 into the battery cooler 15
and the exhaust gas cooler 17. Then, the coolants flowing in
parallel through the battery cooler 15 and the exhaust gas cooler
17 are collected into the second switching valve 20 to flow through
the radiator 13, thereby being sucked into the first pump 11.
[0562] On the other hand, as shown in solid arrows in FIG. 41, the
coolant discharged from the second pump 12 flows through the
coolant cooler 14 to be branched into the inverter cooler 16 and
the cooler core 18 by the first switching valve 19. The coolants
flowing in parallel through the inverter cooler 16 and the cooler
core 18 are collected into the second switching valve 20 to be
sucked into the second pump 12.
[0563] In this way, in the second mode, the
intermediate-temperature coolant cooled by the radiator 13 flows
through the exhaust gas cooler 17 and the battery cooler 15,
whereas the low-temperature coolant cooled by the coolant cooler 14
flows through the inverter cooler 16 and the cooler core 18. As a
result, the battery and the exhaust gas are cooled by the
intermediate-temperature coolant, while the inverter and the blast
air into the vehicle interior are cooled by the low-temperature
coolant.
[0564] Thus, the cooling capacity of the inverter can be improved
as compared to that in the second mode in which the battery can
also be cooled by the low-temperature coolant.
[0565] When the battery temperature Tbatt is determined to exceed
50.degree. C. in step S270, the priority of cooling of the battery
is determined to be high, and the operation proceeds to step S290,
in which a fourth mode shown in FIG. 42 is performed.
[0566] In the fourth mode, the controller 40 controls the electric
motor 30 for a switching valve such that the first and second
switching valves 19 and 20 are brought into the fourth state shown
in FIG. 42 to thereby operate the first and second pumps 11 and 12
and the compressor 23.
[0567] Thus, the first switching valve 19 connects the inlet 19a
with the outlet 19d, and also connects the inlet 19b with the
outlets 19e and 19f, thereby closing the outlet 19c. The second
switching valve 20 closes the inlet 20a and connects the inlet 20b
with the outlet 20e, and also connects the inlets 20c and 20d with
the outlet 20f.
[0568] Accordingly, an intermediate-temperature coolant circuit is
formed of the first pump 11, the exhaust gas cooler 17, and the
radiator 13, whereas a low-temperature coolant circuit is formed of
the second pump 12, the coolant cooler 14, the battery cooler 15,
and the inverter cooler 16.
[0569] That is, as indicated by an alternate long and short dashed
arrow of FIG. 42, the coolant discharged from the first pump 11
flows through the exhaust gas cooler 17 via the first switching
valve 19, and then through the radiator 13 via the second switching
valve 20, thereby being sucked into the first pump 11.
[0570] On the other hand, as indicated by solid arrows in FIG. 41,
the coolant discharged from the second pump 12 flows through the
coolant cooler 14, and is branched by the first switching valve 19
into the battery cooler 15 and the inverter cooler 16. Then, the
coolants flowing in parallel through the battery cooler 15, and the
inverter cooler 16 are collected into the second switching valve 20
to be sucked into the second pump 12. In contrast, as indicated by
a dashed arrow in FIG. 41, the coolant does not circulate through
the cooler core 18.
[0571] In this way, in the second mode, the
intermediate-temperature coolant cooled by the radiator 13 flows
through the exhaust gas cooler 17, whereas the low-temperature
coolant cooled by the coolant cooler 14 flows through the battery
cooler 15 and the inverter cooler 16, stopping the circulation of
the coolant toward the cooler core 18. As a result, the battery and
the exhaust gas are cooled by the intermediate-temperature coolant,
and the inverter is cooled by the low-temperature coolant, thereby
stopping the cooling (that is, air conditioning) of the blast air
into the vehicle interior.
[0572] Thus, the cooling capabilities of the battery and the
inverter can be improved as compared to those in the second mode in
which the blast air into the vehicle interior can also be cooled by
the low-temperature coolant.
[0573] In this embodiment, when the inverter temperature Tiny is
higher than the predetermined temperature (60.degree. C. in this
example), the third mode is performed to allow the coolant to
circulate between the inverter cooler 16 and the second pump 12,
and also to circulate between the battery cooler 15 and the first
pump 11. Thus, when the inverter temperature is high, the inverter
with a smaller heat capacity can be preferentially cooled as
compared to the battery with a larger heat capacity. As a result,
the inverter can be effectively cooled while suppressing the
increase in temperature of the battery.
Third Reference Example
[0574] As shown in FIG. 45, a third reference example of the
invention includes a coolant tank 70 for storing the coolant
therein, in addition to the structure of the first reference
example.
[0575] The coolant tank 70 is provided with a first coolant
outlet/inlet 70a and a second coolant outlet/inlet 70b. The first
coolant outlet/inlet 70a is connected to a first branch portion 71
provided between the outlet 20e of the second switching valve 20
and a coolant inlet side of the radiator 13. The second coolant
outlet/inlet 70b is connected to a second branch portion 72
provided between an outlet 20f of the second switching valve 20 and
a suction side of the second pump 12.
[0576] Thus, a coolant flow path of the first coolant circuit
(coolant circuit on the first pump 11 side) on the suction side of
the first pump 11 communicates with a coolant flow path of the
second coolant circuit (coolant circuit on the second pump 12 side)
on the suction side of the second pump 12 via the coolant tank
70.
[0577] In this embodiment, the first coolant circuit communicates
with the second coolant circuits, which can equalize the internal
pressure between the first and second coolant circuits.
[0578] Thus, a difference in pressure acting on a valve element
inside each of the first and second switching valves 19 and 20 can
be decreased to thereby prevent the leakage of the coolant in the
switching valve.
[0579] For example, given that the first coolant circuit and the
second coolant circuit communicate together on the discharge side
of one pump as well as on the suction side of the other pump, the
coolant circuit communicating on the suction side of the pump might
have its internal pressure abnormally increased. In contrast, in
this embodiment, the first coolant circuit and the second coolant
circuit communicate with each other on the suction sides of both
pumps, which can prevent the internal pressure of the coolant
circuits from abnormally increasing, thereby facilitating the
design of parts with good pressure resistance.
Fourth Reference Example
[0580] Although in the third reference example, the first coolant
circuit and the second coolant circuit communicate with each other
on the suction sides of both the pumps, in a fourth reference
example of the invention, as shown in FIG. 46, the first coolant
circuit and the second coolant circuit communicate with each other
on the discharge sides of both the pumps.
[0581] Specifically, the first branch portion 71 of the first
coolant circuit is provided between the discharge side of the first
pump 11 and the inlet 19a of the first switching valve 19, and the
second branch portion 72 of the second coolant circuit is provided
between the discharge side of the second pump 12 and the inlet 19b
of the first switching valve 19.
[0582] Although in the third reference example, the coolant tank 70
is provided with the first coolant outlet/inlet 70a for connection
with the first coolant circuit, and the second coolant outlet/inlet
70b for connection with the second coolant circuit, in a fourth
reference example, the coolant tank 70 is provided with one coolant
outlet/inlet 70c connected to both the first and second coolant
circuits.
[0583] Together with this, one coolant pipe connected to the
coolant outlet/inlet 70c of the coolant tank 70 is branched from
the coolant tank 70 side into two parts toward the first branch
portion 71 and the second branch portion 72.
[0584] This embodiment can also obtain the same operation and
effects as those of the third reference example described
above.
Eighth Embodiment
[0585] An eighth embodiment of the invention specifically shows the
structure of the coolant cooler 14 and condenser 50 in the first
embodiment.
[0586] FIG. 47 shows a perspective view of a heat exchanger 80
including the coolant cooler 14 and the condenser 50. FIG. 48 shows
a perspective view of a cutout portion of the structure shown in
FIG. 47. The upward and downward arrows shown in FIGS. 47 and 48
indicate the vertical direction of the vehicle (or the direction of
gravitational force).
[0587] The heat exchanger 80 includes a heat exchanging portion
801, an upper tank portion 802, and a lower tank portion 803. The
heat exchanging portion 801 is formed by stacking (arranging in
parallel) a plurality of tubes 804 for the coolant and a plurality
of tubes 805 for the refrigerant. The stacking direction of the
tubes 804 for the coolant and the tubes 805 for the refrigerant
(namely, the left-right direction shown in FIGS. 47 and 48) is
hereinafter referred to as a "stacking direction of the tubes". In
this example, the tubes 804 for the coolant and the tubes 805 for
the refrigerant are alternately stacked on each other.
[0588] The upper tank portion 802 includes a tank space 802a for an
upper coolant (tank space for a heat medium), and a tank space 802b
for an upper refrigerant. The tank space 802a for the upper coolant
is adapted to collect the coolants for a plurality of tubes 804 for
the coolant. The tank space 802b for the upper refrigerant is
adapted to distribute and collect the coolant with respect to a
plurality of tubes 805 for the refrigerant.
[0589] The lower tank portion 803 includes a tank space 803a for a
lower coolant (tank space for a heat medium), and a tank space 803b
for a lower refrigerant. The tank space 803a for the lower
refrigerant is adapted to distribute the coolant to a plurality of
tubes 804 for the coolant. The tank space 803b for the lower
refrigerant is adapted to distribute the coolant and collect the
coolants for a plurality of tubes 805 for the refrigerant.
[0590] The tank space 802a for the upper coolant and the tank space
803a for the lower coolant are diagonally positioned as viewed from
the tube stacking direction. The tank space 802b for the upper
refrigerant and the tank space 803b for the lower refrigerant are
diagonally positioned as viewed from the tube stacking
direction.
[0591] The heat exchanger 80 is mounted on the vehicle such that
the longitudinal direction of each of the tubes 804 for the coolant
and the tubes 805 for the refrigerant (hereinafter referred to as a
tube longitudinal direction) conforms to the vertical direction of
the vehicle (or the direction of gravitational force).
[0592] The heat exchanger 80 is formed by stacking and bonding a
number of plate members 806 in the tube stacking direction. The
plate member 806 is a plate having a substantially elongated
rectangular shape, and formed, for example, using a both-sided clad
material including an aluminum center layer with both sides thereof
clad with brazing.
[0593] An overhanging portion 806a is formed at the outer
peripheral edge of the substantially rectangular plate member 806.
The overhanging portion 806a protrudes in the direction
perpendicular to the plate surface of the plate member 806 (in the
tube stacking direction). A number of plate members 806 are stacked
on each other with the respective overhanging portions 806a bonded
together by brazing.
[0594] The arrangement directions of the plate members 806 (the
directions in which protruding tips of the overhanging portions
806a are oriented) are the same except for one plate member 806A
positioned at one end in the tube stacking direction (on the left
end shown in FIGS. 47 and 48).
[0595] The respective tank spaces 802a, 802b, 803a, and 803b are
formed by cylindrical portions 806b of the plate members 806. Each
cylindrical portion 806b cylindrically protrudes in the direction
opposite to the protruding direction of the overhanging portion
806a. The cylindrical portion 806b has a communication hole formed
therein.
[0596] The cylindrical portion 806b of the plate member 806 is
formed such that the tank spaces 802a and 803a for the coolant do
not communicate with the tube 805 for the refrigerant, and such
that the tube 804 for the coolant does not communicate with the
tank spaces 802b and 803b for the refrigerant.
[0597] One side part of the heat exchanger 80 in the tube stacking
direction (left part shown in FIGS. 47 and 48) constitutes the
condenser 50, whereas the other side part of the heat exchanger 80
in the tube stacking direction (right part shown in FIGS. 47 and
48) constitutes the coolant cooler 14.
[0598] The plate member 806A positioned on one end in the tube
stacking direction (on the left end shown in FIGS. 47 and 48) is
provided with a refrigerant inlet 80a of the condenser 50 and a
refrigerant outlet 80b of the condenser 50. The refrigerant inlet
80a of the condenser 50 communicates with the tank space 802b for
the upper refrigerant. The refrigerant outlet 80b of the condenser
50 communicates with the tank space 803b for the lower
refrigerant.
[0599] Connectors 807 for the refrigerant are respectively attached
to the refrigerant inlet 80a and refrigerant outlet 80b of the
condenser 50. A connector 807 for the refrigerant is formed by
cutting or the like, and bonded to the plate member 806 by
brazing.
[0600] The plate member 806B positioned on the other end in the
tube stacking direction (on the right end shown in FIGS. 47 and 48)
is provided with a refrigerant inlet 80c of the coolant cooler 14
and a refrigerant outlet 80d of the coolant cooler 14. The
refrigerant inlet 80c of the coolant cooler 14 communicates with
the tank space 803b for the lower refrigerant. The refrigerant
outlet 80d of the coolant cooler 14 communicates with the tank
space 802b for the upper refrigerant. Other connectors 807 for the
refrigerant are respectively attached to the refrigerant inlet 80c
and refrigerant outlet 80d of the coolant cooler 14.
[0601] The overhanging portion 806a of the plate member 806 on the
condenser 50 side has on its upper surface, a coolant outlet 80e of
the condenser 50. The overhanging portion 806a of the plate member
806 on the condenser 50 side has on its lower surface, a coolant
inlet 80f of the condenser 50. Thus, the coolant outlet 80e and
coolant inlet 80f of the condenser 50 are opened in the
longitudinal direction of the tubes.
[0602] The coolant outlet 80e of the condenser 50 communicates with
the tank space 802a for the upper coolant. The coolant inlet 80f of
the condenser 50 communicates with the tank space 803a for the
lower coolant. Other connectors 808 for the coolant are
respectively attached to the coolant outlet 80e and coolant inlet
80f of the condenser 50. Each of connectors 808 for the coolant is
formed by cutting or the like, and bonded to the plate member 806
by brazing.
[0603] The overhanging portion 806a of the plate member 806 on the
coolant cooler 14 side has on its upper surface, a coolant outlet
80g of the coolant cooler 14. The overhanging portion 806a of the
plate member 806 on the coolant cooler 14 side has on its lower
surface, a coolant inlet 80h of the coolant cooler 14. Thus, the
coolant outlet 80g and coolant inlet 80h of the coolant cooler 14
are opened in the longitudinal direction of the tubes.
[0604] The coolant outlet 80g of the coolant cooler 14 communicates
with the tank space 802a for the upper coolant. The coolant inlet
80h of the coolant cooler 14 communicates with the tank space 803a
for the lower coolant. Other connectors 808 for the coolant are
respectively attached to the coolant outlet 80g and coolant inlet
80h of the coolant cooler 14.
[0605] The coolant inlets 80f and 80h and coolant outlets 80e and
80g are formed by holes formed in the overhanging portions 806a of
the plate members 806.
[0606] Although in this example, the coolant inlets 80f and 80h and
the coolant outlets 80e and 80g are opened in the tube longitudinal
direction, the coolant inlets 80f and 80h and the coolant outlets
80e and 80g may be opened in the direction perpendicular to both
the tube longitudinal direction and the tube stacking direction.
That is, the coolant inlets 80f and 80h and coolant outlets 80e and
80g may be formed in a side surface of the overhanging portion 806a
in the plate member 806.
[0607] A cavity formation portion 809 is formed at the boundary
between the condenser 50 and the coolant cooler 14. The cavity
formation portion 809 is provided with a cavity 809a into which
both the coolant and refrigerant do not flow.
[0608] Specifically, the cavity formation portion 809 is formed by
closing the cylindrical portion 806b of a plate member 806C
positioned at a boundary between the condenser 50 and the coolant
cooler 14, and bonding the plate member 806C positioned at the
boundary to an adjacent plate member 806D.
[0609] The cavity 809a serves to suppress the heat transfer between
a condenser heat exchanging portion (first heat exchanging portion)
801a of the heat exchanging portion 801 forming the condenser 50,
and a coolant cooler heat exchanging portion (second heat
exchanging portion) 801b of the heat exchanging portion 801 forming
the coolant cooler 14.
[0610] A recessed portion may be formed in a plate surface of the
plate member 806C positioned at the boundary between the condenser
50 and the coolant cooler 14, and abutted against and bonded to the
adjacent plate member 806D. The recessed portion can be formed in
various shapes, including a shape extending in the tube
longitudinal direction, a shape extending in the tube short
direction, and the like.
[0611] FIG. 49 shows an exemplary diagram of the flow of coolant
and the flow of refrigerant in the heat exchanger 80. In the
coolant cooler 14, the coolant flows from the coolant inlet 80h
into the tank space 803a for the lower coolant. In the tank space
803a for the lower coolant, the coolant is then distributed to the
tubes for the coolant of the coolant cooler heat exchanging
portions 801b in the tank space 803a for the lower coolant. After
flowing through the tubes for the coolant of the coolant cooler
heat exchanging portion 801b, the coolants are collected into the
tank space 802a for the upper coolant to flow out of the coolant
outlet 80g.
[0612] In the coolant cooler 14, the refrigerant flows from the
refrigerant inlet 80d into the tank space 803b for the lower
refrigerant. In the tank space 803b for the lower refrigerant, the
refrigerant is then distributed to the tubes for the refrigerant of
the coolant cooler heat exchanging portion 801b. After flowing
through the tubes for the refrigerant of the coolant cooler heat
exchanging portion 801b, the coolants are collected into the tank
space 802b for the upper refrigerant to flow out of the refrigerant
outlet 80c.
[0613] In the condenser 50, the coolant flows from the coolant
inlet 80f into the tank space 803a for the lower coolant. In the
tank space 803a for the lower coolant, the coolant is then
distributed to the tubes for the coolant of the condenser heat
exchanging portion 801a. After flowing through the tubes for the
coolant of the condenser heat exchanger 801a, the coolants are
collected into the tank space 802a for the upper coolant to flow
out of the coolant outlet 80e.
[0614] In the condenser 50, the refrigerant flows from the
refrigerant inlet 80a into the tank space 802b for the upper
refrigerant. In the tank space 802b for the upper refrigerant, the
refrigerant is then distributed to the tubes for the refrigerant of
the condenser heat exchanging portion 801a. After flowing through
the tubes for the refrigerant of the condenser heat exchanging
portion 801a, the refrigerants are collected into the tank space
803b for the lower refrigerant to flow out of the refrigerant
outlet 80b.
[0615] As shown in FIG. 50, the coolant inlets 80f and 80h are
diagonally disposed with respect to the coolant outlets 80e and 80g
as viewed in the tube stacking direction, which results in improved
distribution of the coolant to the tubes for the coolant. In a
modified example shown in FIG. 51, the coolant inlets 80f and 80h
and the coolant outlets 80e and 80g may be located in the same
position in the thickness direction of the heat exchanger 80 as
viewed in the tube stacking direction.
[0616] In an example shown in FIG. 49, the coolant inlets 80f and
80h and the coolant outlets 80e and 80g are located in the same
position in the tube stacking direction as viewed from the front
surface direction (specifically, the direction perpendicular to the
paper surface of FIG. 49). In contrast, in a modified example shown
in FIG. 52, the coolant inlets 80f and 80h are diagonally disposed
with respect to the coolant outlets 80e and 80g as viewed from the
front surface direction (in the direction perpendicular to both the
tube stacking direction and the longitudinal direction of the
tube), which results in improved distribution of the coolant to the
tubes for the coolant.
[0617] Like the above first embodiment, in this embodiment, the
coolant inlets 80f and 80h and the coolant outlets 80e and 80g are
disposed between the plate members 806A and 806B positioned on both
ends of the tank portions 802 and 803 in the stacking direction of
tubes, which can increase the flexibility in connection of pipes
and arrangement of the heat exchangers.
[0618] Preferably, the coolant inlets 80f and 80h are disposed in
the lower tank portion 803, and the coolant outlets 80e and 80g are
disposed in the upper tank portion 802. The coolant flows from the
lower side to the upper side, making it easier to release air mixed
in the coolant.
[0619] In the heat exchanging portion 801a of the condenser 50, the
refrigerant flow is desirably a descending flow or horizontal flow.
The flow direction of the refrigerant is identical to the dropping
direction of a condensed liquid, so that the refrigerant can flow
smoothly without interruption of the drop of the condensed liquid
by the refrigerant flow.
[0620] In the coolant cooler 14, the refrigerant inlet 80c is
preferably disposed in the lower tank portion 803 with improved
distribution of the coolant.
[0621] In an accumulator cycle, as shown in FIGS. 49 and 52, the
coolant and the refrigerant preferably flow through the coolant
cooler 14 in the same direction. As illustrated in FIG. 53, good
performance can be obtained.
[0622] The accumulator cycle is a refrigeration cycle in which an
accumulator (gas-liquid separator) is disposed on the suction side
of a compressor.
[0623] In a modified example shown in FIG. 54, the refrigerant
inlet 80c and the refrigerant outlet 80d are reversed in position
with respect to the example shown in FIG. 52. That is, the
refrigerant inlet 80c is disposed in the upper tank portion 802,
while the refrigerant outlet 80d is disposed in the lower tank
portion 803.
[0624] In a receiver cycle, as shown in FIG. 54, the coolant and
the refrigerant preferably flow through the coolant cooler 14 in
opposite directions to each other. As illustrated in FIG. 55, good
performance can be obtained. In this case, in order to suppress the
deterioration of distribution of the refrigerant, the number of
tubes for the refrigerant (or the number of paths) is preferably
increased.
[0625] The receiver cycle is a refrigeration cycle in which a
receiver (liquid receiver) is disposed between a radiator and an
expansion valve.
[0626] The coolant inlets 80f and 80h, and the coolant outlets 80e
and 80g may be reversed in position with respect to this
embodiment. Alternatively, the coolant inlets 80f and 80h and the
coolant outlets 80e and 80g may be reversed in position, and the
refrigerant inlets 80a and 80c and the refrigerant outlets 80b and
80d may also be reversed in position.
[0627] At least one of the coolant inlets 80f and 80h, the coolant
outlets 80e and 80g, the refrigerant inlets 80a and 80c, and the
refrigerant outlets 80b and 80d is disposed between both ends of
each of the tank portions 802 and 803 in the tube stacking
direction, which can increase the flexibility in connection of the
pipes and arrangement of the heat exchangers as compared to the
case where all the inlets and outlets are disposed at either of the
plate members 806A and 806B positioned on both ends of the tank
portions 802 and 803.
[0628] In this embodiment, the cavity 809a is formed between the
condenser 50 and the coolant cooler 14, thereby suppressing the
heat transfer between the condenser 50 and the coolant cooler 14.
In the heat exchanging portion 801a of the condenser 50, the tube
located closest to the coolant cooler 14 may serve as a tube for
the coolant so as to suppress the heat transfer between the
condenser 50 and the coolant cooler 14. Likewise, in the heat
exchanging portion 801b of the coolant cooler 14, the tube located
closest to the condenser 50 may serve as a tube for the coolant so
as to suppress the heat transfer between the condenser 50 and the
coolant cooler 14.
[0629] That is, the tube for the refrigerant of the condenser 50 is
not disposed adjacent to the tube for the refrigerant of the
coolant cooler 14, which can suppress the heat transfer between the
condenser 50 and the coolant cooler 14.
Ninth Embodiment
[0630] Although in the eighth embodiment, a number of plate members
806 are oriented in the same direction except for the plate member
806A located on one end in the tube stacking direction, in a ninth
embodiment, as shown in FIGS. 56 and 57, the plate members 806 are
oriented in opposite directions with the cavity formation portion
809 centered therebetween.
[0631] The cavity formation portion 809 is formed by stacking two
plate members 806C together with the respective protruding tips of
the overhanging portions 806a abutted against each other. Thus, the
cavity 809a is formed between the two plate members 806C.
[0632] The plate members 806 on the condenser 50 side and the plate
members 806 on the coolant cooler 14 side are stacked together with
the respective protruding tips of the overhanging portions 806a
directed toward the cavity formation portion 809. In other words,
the plate members 806 on the condenser 50 side and the plate
members 806 on the coolant cooler 14 side are disposed opposite
(symmetrically) to each other in the tube stacking direction.
[0633] The two plate members 806C are bonded together to form the
cavity formation portion 809. With this arrangement, even in case
of breakage of the connection between the two plate members 806C
due to thermal strain, the leak of the coolant and refrigerant can
be prevented.
[0634] Margins for brazing of the two plate members 806C preferably
have a longer length in a longitudinal direction of the plate
member 806 (or in the tube longitudinal direction) than another
length in a short-direction of the plate member 806 (or in the tube
short direction). As the margin for brazing becomes longer, the
amount of extension of the plate member becomes more, so that the
plate member is more likely to be broken. By setting the margin for
brazing in the longitudinal direction of the plate member 806
longer than that in the short direction thereof, the breakage due
to the thermal strain can be suppressed.
[0635] Alternatively, recessed portions may be formed at the plate
surfaces of the two plate members 806C to be abutted against each
other, and then the two recessed portions of the two plate members
806C may be bonded together. The recessed portion may be formed in
various shapes, including a shape extending in the tube
longitudinal direction, a shape extending in the tube short
direction, and the like.
Tenth Embodiment
[0636] Although in the above eighth embodiment, the coolant inlets
80f and 80h and the coolant outlets 80e and 80g are composed of
holes formed in the overhanging portions 806a of the plate members
806, in a tenth embodiment, as shown in FIGS. 58 and 59, the
coolant inlets 80f and 80h, as well as the coolant outlets 80e and
80g are formed of a pair of openings independently formed from the
plate members 806.
[0637] Each opening formation member 810 is formed of a
semi-cylindrical plate material. Specifically, the opening
formation member 810 is formed using a both-sided clad material
including an aluminum center layer with both sides thereof clad
with brazing. The pair of opening formation members 810 are bonded
together to form a cylindrical member. The openings formed in the
cylindrical member constitute the coolant inlets 80f and 80h and
the coolant outlets 80e and 80g.
[0638] In this example, the pair of opening formation members 810
are stacked on each other in the tube stacking direction. The
internal space of the cylindrical member formed by the pair of
opening formation members 810 communicates with the tank spaces
802a and 803a for the coolant.
[0639] The pair of opening formation members 810 are bonded to the
plate members 806 by brazing while being inserted into recessed
portions 806d formed at the upper and lower edges of the plate
member 806 (edges on both ends in the tube longitudinal
direction).
[0640] The plate members 806 are disposed in opposite directions
with the opening formation member 810 centered therebetween.
Specifically, the plate member 806 is disposed such that the
protruding tip of the overhanging portion 806a is directed opposite
to the opening formation member 810.
[0641] Like the ninth embodiment, the plate members 806 are
disposed in the opposite (symmetrical) directions to each other
with the cavity formation portion 809 centered.
[0642] According to this embodiment, the opening area of each of
the coolant inlets 80f and 80h and the coolant outlets 80e an 80g
can be increased to achieve good inflow and outflow of the coolant
as compared to the above eighth embodiment.
Eleventh Embodiment
[0643] Although in the above tenth embodiment, the pair of opening
formation members 810 are inserted into the upper edge and lower
edge of the plate member 806, in an eleventh embodiment, as shown
in FIGS. 60 and 61, a pair of opening formation members 811
(multiple members) extend from the upper end to lower end of the
plate member 806 to be stacked while being sandwiched between the
plate members 806.
[0644] Each opening formation member 811 is formed of a plate
material with a substantially elongated rectangular shape which is
the same as that of the plate member 806. Specifically, the opening
formation member 811 is formed using a both-sided clad material
including an aluminum center layer with both sides thereof clad
with brazing.
[0645] An overhanging portion 811a is formed at the outer
peripheral edge of the substantially rectangular opening formation
member 811. The overhanging portion 806a protrudes in the direction
perpendicular to the plate surface of the opening formation member
811 (in the tube stacking direction). Specifically, a pair of
opening formation members 811 is disposed such that the respective
protruding tips of the overhanging portions 811a are directed
opposite to each other.
[0646] The plate members 806 are disposed in opposite directions
with the pair of opening formation member 811 centered
therebetween. The plate members 806 and opening formation member
811 are stacked on each other such that the protruding tips of the
overhanging portions 806a and 811a are oriented in the same
direction, whereby the overhanging portions 806a and 811a are
bonded together by brazing.
[0647] The pair of opening formation members 811 is provided with
recessed portions at its upper edge and lower edge (at both edges
in the tube longitudinal direction). The recessed portions are
superimposed on each other to form openings, which include any one
of the coolant inlets 80f and 80h and the coolant outlets 80e and
80g.
[0648] Like the tenth embodiment, the plate members 806 are
disposed in the opposite (symmetrical) directions to each other
with the cavity formation portion 809 centered.
[0649] In this embodiment, the plate opening formation members 811
are stacked on each other like the plate member 806, whereby the
coolant inlets 80f and 80h and the coolant outlets 80e and 80g can
be formed. Thus, the heat exchanger of this embodiment can be more
easily manufactured than that of the tenth embodiment.
Twelfth Embodiment
[0650] Although in the above eighth embodiment, the only one
coolant outlet 80e of the condenser 50 is formed, in a twelfth
embodiment, as shown in FIG. 62, a plurality of coolant outlets 80e
of the condenser 50 are formed.
[0651] In this example, the tubes 804 for the coolant and the tubes
805 for the refrigerant are alternately arranged. The coolant
outlets 80e are formed by holes formed in the overhanging portions
806a of the plate members 806 that form the tubes 804 for the
coolant.
[0652] A connector 82 for the coolant is attached to the coolant
outlets 80e. The connector 82 for the coolant is formed by cutting
or the like, and bonded to the plate member 806 by brazing. The
connector 82 for the coolant includes a plurality of coolant inlets
82a, a coolant flow path 82b, and one coolant outlet 82c.
[0653] The coolant inlets 82a of the connector 82 for the coolant
are provided corresponding to the coolant outlets 80e of the
condenser 50. The coolant flow path 82b of the connector 82 for the
coolant collects the coolants entering the coolant inlets 82a. The
coolant collected by the coolant flow path 82b flows out of one
coolant outlet 82c of the connector 82 for the coolant.
[0654] In this embodiment, a plurality of coolant outlets 80e are
formed in the condenser 50, thereby allowing the good outflow of
the coolant as compared to the case of formation of one coolant
outlet 80e in the condenser 50 like the above eighth
embodiment.
[0655] Like the coolant outlets 80e of the condenser 50, there may
be provided a plurality of coolant inlets 80f of the condenser 50,
the coolant outlets 80g of the coolant cooler 14, and the coolant
inlets 80h of the coolant cooler 14.
Thirteenth Embodiment
[0656] Although in the above eighth embodiment, the heat exchanger
80 is composed of the coolant cooler 14 and condenser 50, in a
thirteenth embodiment, as shown in FIGS. 63 and 64, the heat
exchanger 80 is composed of the coolant cooler 14, the condenser
50, and an auxiliary heat exchanger 83.
[0657] In an example shown in FIGS. 63 and 64, the auxiliary heat
exchanger 83 is an internal heat exchanger for exchanging heat
between a liquid-phase refrigerant (first fluid) condensed by the
condenser 50 and a gas-phase refrigerant (second fluid) evaporated
by the coolant cooler 14.
[0658] The auxiliary heat exchanger 83 is disposed between the
condenser 50 and the coolant cooler 14. Thus, an auxiliary heat
exchanging portion 801c forming the auxiliary heat exchanger 83 of
the heat changing portion 801 is disposed between a condenser heat
exchanging portion 801a and a coolant cooler heat exchanging
portion 801b.
[0659] The auxiliary heat exchanging portion 801c includes a
laminate of tubes 812 for a first refrigerant (tubes for a first
fluid) through which the liquid-phase refrigerant condensed by the
condenser 50 flows, and tubes 813 for a second refrigerant (tubes
for a second fluid) through which the gas-phase refrigerant
evaporated by the coolant cooler 14 flows.
[0660] In order to enhance the heat exchanging properties of the
auxiliary heat exchanging portion 801c, one of the tube 812 for the
first refrigerant and the tube 813 for the second refrigerant is
sandwiched between the tubes of the other type. More preferably,
the tubes 812 for the first refrigerant and the tubes 813 for the
second refrigerant are alternately arranged.
[0661] The refrigerant outlets 80i and 80j for allowing the
refrigerant (internal fluid) to flow from the auxiliary heat
exchanger 83 are formed of holes located at the upper surface and
lower surface of the overhanging portion 806a of the plate member
806.
[0662] The refrigerant outlets 80i and 80j of the auxiliary heat
exchanger 83 are disposed between a boundary (first boundary)
located between the condenser 50 and the auxiliary heat exchanger
83, and another boundary (second boundary) located between the
auxiliary heat exchanger 83 and the coolant cooler 14.
[0663] The refrigerant outlet 80i on the upper side of the
auxiliary heat exchanger 83 communicates with the tank space 802b
for the upper refrigerant. The refrigerant outlet 80i on the lower
side of the auxiliary heat exchanger 83 communicates with the tank
space 803b for the lower refrigerant.
[0664] The plate member 806A positioned on one end in the tube
stacking direction (on the left end shown in FIGS. 63 and 64) is
provided with the refrigerant inlet 80a of the condenser 50. The
refrigerant inlet 80a of the condenser 50 communicates with the
tank space 802b for the upper refrigerant. The connector 807 for
the refrigerant is attached to the refrigerant inlet 80a of the
condenser 50.
[0665] The plate member 806B positioned on the other end in the
tube stacking direction (on the right end shown in FIGS. 63 and 64)
is provided with the refrigerant inlet 80c of the coolant cooler
14. The refrigerant inlet 80c of the coolant cooler 14 communicates
with the tank space 803b for the lower refrigerant. Another
connector 807 for the refrigerant is attached to the refrigerant
inlet 80c of the coolant cooler 14.
[0666] The overhanging portion 806a of the plate member 806 on the
condenser 50 side has on its upper surface, the coolant outlet 80e
of the condenser 50. The overhanging portion 806a of the plate
member 806 on the condenser 50 side has on its lower surface, the
coolant inlet 80f of the condenser 50.
[0667] The coolant outlet 80e of the condenser 50 communicates with
the tank space 802a for the upper coolant. The coolant inlet 80f of
the condenser 50 communicates with the tank space 803a for the
lower coolant. Other connectors 808 for the coolant are
respectively attached to the coolant outlet 80e and coolant inlet
80f of the condenser 50.
[0668] The overhanging portion 806a of the plate member 806 on the
coolant cooler 14 side has on its upper surface, the coolant inlet
80h of the coolant cooler 14. The overhanging portion 806a of the
plate member 806 on the coolant cooler 14 side has on its lower
surface, the coolant outlet 80g of the coolant cooler 14.
[0669] The coolant inlet 80h of the coolant cooler 14 communicates
with the tank space 802a for the upper coolant. The coolant outlet
80g of the coolant cooler 14 communicates with the tank space 803a
for the lower coolant. The connectors 808 for the coolant are
respectively attached to the coolant inlet 80h and coolant outlet
80g of the coolant cooler 14.
[0670] The coolant inlets 80f and 80h and coolant outlets 80e and
80g are formed by holes formed in the overhanging portions 806a of
the plate members 806.
[0671] The plate member 806E positioned at the boundary between the
condenser 50 and the auxiliary heat exchanger 83 is formed to
connect the tank space 803b for the lower refrigerant with the
condenser 50 side and the auxiliary heat exchanger 83 side, and not
to connect other tank spaces 802a, 802b, and 803a with the
condenser 50 side and the auxiliary heat exchanger 83 side.
[0672] Thus, the liquid-phase refrigerant condensed by the
condenser heat exchanging portion 801a flows into the auxiliary
heat exchanging portion 801c through the tank space 803b for the
lower refrigerant (tank space for the first fluid).
[0673] A part of the tank space 803b for the lower refrigerant
corresponding to the heat exchanging portion 801a of the condenser
50 is superimposed on a part of the space 803b corresponding to the
heat exchanging portion 801c of the auxiliary heat exchanger 83 as
viewed from the tube stacking direction.
[0674] The plate member 806F positioned at the boundary between the
auxiliary heat exchanger 83 and the coolant cooler 14 is formed to
connect the tank space 802b for the upper refrigerant with the
auxiliary heat exchanger 83 side and the coolant cooler 14 side,
and not to communicate other tank spaces 802a, 803a, and 803b with
the auxiliary heat exchanger 83 side and the coolant cooler 14
side.
[0675] Thus, the gas-phase refrigerant evaporated by the coolant
cooler heat exchanging portion 801b flows into the auxiliary heat
exchanging portion 801c through the tank space 802b for the upper
refrigerant (tank space for the second fluid).
[0676] A part of the tank space 802b for the upper refrigerant
corresponding to the heat exchanging portion 801c of the auxiliary
heat exchanger 83 is superimposed on another part of the tank space
802b corresponding to the heat exchanging portion 801b of the
coolant cooler 14 as viewed from the tube stacking direction.
[0677] As indicated by the arrow A1 in FIG. 65, the refrigerant
flowing from the refrigerant inlet 80a on the condenser 50 side
into the condenser 50 flows through the tank space 802b for the
upper refrigerant, the condenser heat exchanging portion 801a, and
the tank space 803b for the lower refrigerant in that order to
enter the auxiliary heat exchanger 83. Then, the refrigerant flows
out of the upper side refrigerant outlet 80i through the auxiliary
heat exchanging portion 801c.
[0678] As indicated by the arrow A2 in FIG. 65, the refrigerant
flowing from the refrigerant inlet 80c on the coolant cooler 14
side into the coolant cooler 14 flows through the tank space 803b
for the lower refrigerant, the coolant cooler heat exchanging
portion 801b, and the tank space 802b for the upper refrigerant in
that order to enter the auxiliary heat exchanger 83. Then, the
refrigerant flows out of the lower side refrigerant outlet 80j
through the auxiliary heat exchanging portion 801c.
[0679] At this time, the auxiliary heat exchanging portion 801c
exchanges heat between the refrigerant flowing thereinto from the
condenser 50 and the refrigerant flowing thereinto from the coolant
cooler 14.
[0680] In this embodiment, the inlet and outlet for the coolant
(fluid not passing through the auxiliary heat exchanger 83) are
opened in the direction perpendicular to the tube stacking
direction, whereas the inlet and outlet for the refrigerant (fluid
passing through the auxiliary heat exchanger 83) are opened in the
tube stacking direction.
[0681] In contrast, the inlet and outlet for the refrigerant (fluid
passing through the auxiliary heat exchanger 83) are opened in the
direction perpendicular to the tube stacking direction, whereas the
inlet and outlet for the coolant (fluid passing through the
auxiliary heat exchanger 83) are opened in the tube stacking
direction, which can decrease the number of inlets and outlets
opened in the direction perpendicular to the tube stacking
direction.
[0682] In this embodiment, internal fluid inlet and outlet 80i and
80j of the auxiliary heat exchanger 83 are formed of holes made at
the upper and lower surfaces of the overhanging portion 806a of the
plate member 806. Alternatively, like the above eleventh
embodiment, the internal fluid inlet and outlet 80i and 80j of the
auxiliary heat exchanger 83 may be formed of a pair of opening
formation members 811 each extending from the upper end to the
lower end of the plate member 806.
[0683] The auxiliary heat exchanger 83 is not limited to the
internal heat exchanger, and may be a supercooler or a
coolant/coolant heat exchanger.
[0684] The supercooler is a heat exchanger for exchanging heat
between the coolant and the liquid-phase refrigerant condensed by
the condenser 50, further cooling the liquid-phase refrigerant to
increase the degree of supercooling of the refrigerant.
[0685] The coolant/coolant heat exchanger is a heat exchanger for
exchanging heat between the coolant having passing through the
condenser 50 and the coolant having passed through the coolant
cooler 14.
Fourteenth Embodiment
[0686] In a fourteenth embodiment, the arrangement of the inlet and
outlet for fluid (for example, refrigerant in the case of the
internal heat exchanger) flowing through the auxiliary heat
exchanger 83 (hereinafter referred to as "fluid inlet" and "fluid
outlet") is modified with respect to that of the above thirteenth
embodiment.
[0687] In this embodiment, as shown in FIG. 66, a first fluid inlet
84a and a first fluid outlet 84b are disposed between the condenser
50 and the auxiliary heat exchanger 83, whereas a second fluid
inlet 84c and a second fluid outlet 84d are disposed between the
auxiliary heat exchanger 83 and the coolant cooler 14.
[0688] The first fluid inlet 84a is disposed under between the
condenser 50 and the auxiliary heat exchanger 83. The first fluid
outlet 84b is disposed above between the condenser 50 and the
auxiliary heat exchanger 83.
[0689] The second fluid inlet 84c is disposed above between the
auxiliary heat exchanger 83 and the coolant cooler 14. The second
fluid outlet 84d is disposed under between the auxiliary heat
exchanger 83 and the coolant cooler 14.
[0690] Connectors 85 are attached to the first fluid inlet 84a, the
first fluid outlet 84b, the second fluid inlet 84c, and the second
fluid outlet 84d.
[0691] As indicated by the arrow B1 in FIG. 66, the fluid entering
the first fluid inlet 84a flows into one of two tank spaces formed
at the lower end of the condenser 50. As indicated by the arrow B2
in FIG. 66, the fluid in the other of the two tank spaces formed at
the lower end of the condenser 50 flows from the first fluid outlet
84b through the auxiliary heat exchanger 83.
[0692] As indicated by the arrow B3 in FIG. 66, the fluid entering
the second fluid inlet 84c flows into one of two tank spaces formed
at the upper end of the coolant cooler 14. As indicated by the
arrow B4 in FIG. 66, the fluid in the other of the two tank spaces
formed at the upper end of the coolant cooler 14 flows from the
second fluid outlet 84d through the auxiliary heat exchanger
83.
[0693] FIG. 67 shows a part in the vicinity of the first fluid
outlet 84b. A pair of plate opening formation members 814 (a
plurality of members) are disposed between the condenser 50 and the
auxiliary heat exchanger 83 to extend from the upper end to lower
end of the plate member 806.
[0694] The first fluid outlet 84b is formed of an opening formed at
the upper surface of the pair of opening formation members 814. The
upper end of the pair of opening formation member 814 is shaped to
expand in the tube stacking direction. The plate members 806
adjacent to the pair of opening formation members 814 have upper
ends thereof recessed in the tube stacking direction, corresponding
to the shape of the pair of opening formation members 814.
[0695] The plate members 806 are disposed opposed to each other in
the tube stacking direction with the opening formation member 814
centered therebetween as the boundary between the condenser 50 and
the auxiliary heat exchanger 83.
[0696] FIG. 68 shows a part in the vicinity of the second fluid
inlet 84c. The structure in the vicinity of the second fluid inlet
84c is the same as that in the vicinity of the first fluid outlet
84b shown in FIG. 67.
[0697] The plate members 806 are disposed opposed to each other in
the tube stacking direction with the opening formation member 814
centered therebetween as the boundary between the auxiliary heat
exchanger 83 and the coolant cooler 14.
[0698] Although not shown in the figure, the structure in the
vicinity of the first fluid inlet 84a and the structure in the
vicinity of the second fluid outlet 84d are also the same as that
in the vicinity of the first fluid outlet 84b shown in FIG. 67 and
that in the vicinity of the second fluid inlet 84c shown in FIG.
68.
[0699] This embodiment does not need to guide a fluid having passed
through the auxiliary heat exchanger 83 to the end of the heat
exchanger 80 in the tube stacking direction in flowing out the
fluid, and thus can simplify the structure of the heat
exchanger.
[0700] The pair of opening formation members 814 in this embodiment
can be applied to the heat exchanger 80 of the above eighth
embodiment. That is, in the heat exchanger 80 of the above eighth
embodiment, the pair of opening formation members 814 may be
disposed between the condenser 50 and the coolant cooler 14 to form
the fluid inlet and outlet. In this case, a cavity may be formed
between the pair of opening formation members 814 to suppress the
heat transfer between the condenser 50 and the coolant cooler 14.
That is, the cavity formation portion 809 of the above eighth
embodiment can be formed by the pair of opening formation members
814.
[0701] In this embodiment, the inlets and outlets for the fluid
flowing through the auxiliary heat exchanger 83 (for example, the
refrigerant in the case of the internal heat exchanger) are
disposed between the condenser 50 and the auxiliary heat exchanger
83, and between the auxiliary heat exchanger 83 and the coolant
cooler 14. Additionally, or alternatively, the inlets and outlets
for the fluid not flowing through the auxiliary heat exchanger 83
(for example, the coolant in the case of the internal heat
exchanger) may be disposed between the condenser 50 and the
auxiliary heat exchanger 83, and between the auxiliary heat
exchanger 83 and the coolant cooler 14.
Fifteenth Embodiment
[0702] A fifteenth embodiment of the invention specifically shows
the structure of the coolant cooler 14, the condenser 50, and the
expansion valve 25 in the seventh embodiment.
[0703] The basic structure of the coolant cooler 14 and condenser
50 is the same as that of the heat exchanger 80 of the above eighth
embodiment. That is, the coolant cooler 14 and condenser 50 are
formed by stacking and bonding a number of plate members 806 in the
tube stacking direction.
[0704] The coolant cooler 14 and the condenser 50 are not bonded
together by brazing. However, the coolant cooler 14 and the
condenser 50 are individually assembled by brazing, and then the
expansion valve 25 is assembled to between the coolant cooler 14
and the condenser 50.
[0705] FIG. 69 is a diagram of the plate member 806 forming the
condenser 50 as viewed from the expansion valve 25. FIG. 70 is a
diagram of the plate member 806 forming the coolant cooler 14 as
viewed from the expansion valve 25.
[0706] With the coolant cooler 14, condenser 50, and expansion
valve 25 integrally assembled together, the tank space 803b for the
lower refrigerant of the condenser 50 (or first tank space for the
refrigerant) and the tank space 803b for the lower refrigerant of
the coolant cooler 14 (or second tank space for the refrigerant)
are positioned to be superimposed on each other as viewed from the
tube stacking direction. Thus, a common plate member can be used as
the plate member 806 forming the condenser 50 and the plate member
806 forming the coolant cooler 14.
[0707] FIG. 71 shows a cross-sectional view of a part in the
vicinity of the expansion valve 25.
[0708] The expansion valve 25 has the decompression flow path 25c
for decompressing the refrigerant flowing from the condenser 50 to
allow the decompressed refrigerant to flow into the coolant cooler
14. The inlet 25d and outlet 25e of the decompression flow path 25c
are disposed in different positions as viewed from the tube
stacking direction.
[0709] The outlet 25e of the decompression flow path 25c is
disposed to be superimposed on the tank space 803b for the lower
refrigerant of the coolant cooler 14 as viewed from the tube
stacking direction. The outlet 25e of the decompression flow path
25c and the tank space 803b for the lower refrigerant of the
coolant cooler 14 are connected and communicate with each other via
the connector 86.
[0710] The inlet 25d of the decompression flow path 25c is disposed
in a position different from that of the tank space 803b for the
lower refrigerant of the condenser 50 as viewed from the tube
stacking direction. A refrigerant flow path formation member 815
forming a refrigerant flow path 815a is disposed between the inlet
25d of the decompression flow path 25c and the tank space 803b for
the lower refrigerant of the condenser 50.
[0711] The refrigerant flow path formation member 815 is a plate
member formed using, for example, a both-sided clad material
including an aluminum center layer with both sides thereof clad
with brazing. The refrigerant flow path formation member 815 is
stacked over and bonded to the plate members 806 forming the
condenser 50 by brazing.
[0712] The refrigerant flow path 815a is a flow path for allowing
the tank space 803b for the lower refrigerant of the condenser 50
to communicate with the inlet 25d of the decompression flow path
25c, and extends non-parallel to the tube stacking direction. The
refrigerant flow path 815a is connected to the inlet 25d of the
decompression flow path 25c via the connector 86.
[0713] In this embodiment, the refrigerant flow path 815a extending
non-parallel to the tube stacking direction is formed between the
inlet 25d of the decompression flow path 25c and the tank space
803b for the lower refrigerant of the condenser 50, so that the
expansion valve 25 with the inlet 25d and outlet 25e of the
decompression flow path 25c not arranged linearly can be assembled
between the coolant cooler 14 and the condenser 50 without any
trouble.
[0714] Contrary to this embodiment, the inlet 25d of the
decompression flow path 25c is superimposed on the tank space 803b
for the lower refrigerant of the condenser 50 as viewed from the
tube stacking direction, and the outlet 25e of the decompression
flow path 25c is disposed in a position different from that of the
tank space 803b for the lower refrigerant of the coolant cooler 14
as viewed from the tube stacking direction. In this case, the
refrigerant flow path 815a extending non-parallel to the tube
stacking direction may be formed between the outlet 25e of the
decompression flow path 25c and the tank space 803b for the lower
refrigerant of the coolant cooler 14.
Other Embodiments
[0715] Various modifications and changes can be made to the
above-mentioned embodiments and reference examples as follows.
[0716] (1) Various devices can be used as the devices to be cooled.
For example, a heat exchanger incorporated in a seat for a
passenger to sit on and adapted to cool and heat the seat by using
coolant may be used as the device to be cooled. The number of
devices to be cooled may be any number as long as the number is a
plural number (two or more).
[0717] (2) The above first reference example shows one example of
the arrangement pattern of holes formed in valve elements of the
first and second switching valves 19 and 20. However, the
arrangement pattern of holes formed in the valve elements of the
first and second switching valves 19 and 20 can be changed in
various manners.
[0718] The connection state between the inlet and outlet for the
coolant can be changed in a variety of ways by modifying the
arrangement pattern of the holes formed in the valve elements of
the first and second switching valves 19 and 20, which can easily
adapt to the change of specifications, including addition of an
operating mode and the like.
[0719] (3) Although in the above first reference example, the
switching is performed among the first to third modes based on the
outside air temperature detected by the outside air sensor 42, the
switching may be performed among the first to third modes based on
the coolant temperature detected by the water temperature sensor
43.
[0720] (4) Although in the above second embodiment, the cold energy
stored in the battery is used to supercool the high-pressure
refrigerant of the refrigeration cycle 22 in the second mode, the
cold energy stored in the battery may be used to cool the air of
the vehicle interior, the inverter, and the like.
[0721] (5) In the reference examples described above, the coolant
cooler 14 for cooling the coolant by the low-pressure refrigerant
of the refrigeration cycle 22 is used as the cooler for cooling the
coolant down to a lower temperature than the outside air
temperature. However, a Peltier device may be used as the
cooler.
[0722] (6) In each of the above-mentioned embodiments and reference
examples, the coolant may intermittently circulate through the
battery cooler 15 to thereby control the cooling capacity for the
battery.
[0723] (7) In each of the above-mentioned embodiments and reference
examples, the switching may be performed between a state of
circulation of the intermediate-temperature coolant through the
exhaust gas cooler 17 and another state of circulation of the
low-temperature coolant therethrough according to a load on an
engine. When a load on the engine is small, for example, while the
vehicle is traveling in midtown, the switching can be performed to
the low-temperature coolant circulation to cool the exhaust gas by
the refrigeration cycle 22, resulting in an increase in density of
exhaust gas returned to the engine intake side, thereby improving
the fuel efficiency.
[0724] (8) In each of the above-mentioned embodiments and reference
examples, the coolant is used as the heat medium for cooling the
device to be cooled. Alternatively, various kinds of media, such as
oil, may be used as the heat medium.
[0725] (9) The refrigeration cycle 22 of each of the above
embodiments and reference examples employs a fluorocarbon
refrigerant as the refrigerant. However, the kind of the
refrigerant is not limited to such a kind of refrigerant.
Specifically, a natural refrigerant, such as carbon dioxide, a
hydrocarbon-based refrigerant, and the like may also be used as the
refrigerant.
[0726] The refrigeration cycle 22 of each of the above embodiments
and reference examples forms a subcritical refrigeration cycle
whose high-pressure side refrigerant pressure does not exceed a
critical pressure of the refrigerant. Alternatively, the
refrigeration cycle may form a supercritical refrigeration cycle
whose high-pressure side refrigerant pressure exceeds the critical
pressure of the refrigerant.
[0727] (10) In each of the above-mentioned embodiments and
reference examples, the vehicle cooling system of the present
disclosure is applied to the hybrid car by way of example.
Alternatively, the present disclosure may be applied to an electric
vehicle which obtains a driving force for traveling from an
electric motor for traveling without including an engine.
[0728] (11) Although in the above respective embodiments, the heat
exchanger 80 is disposed such that the longitudinal direction of
the tubes is identical to the vertical direction, namely, the
direction of gravitational force, the invention is not limited
thereto. The direction of arrangement of the heat exchanger 80 can
be appropriately changed.
[0729] (12) The coolant cooler 14 and condenser 50 of the
above-mentioned embodiments can be applied to a thermal management
system shown in FIGS. 72 and 73.
[0730] In the thermal management system shown in FIGS. 72 and 73,
the condenser 50 is adapted to cool the refrigerant, while heating
the intermediate-temperature coolant by exchanging heat between the
intermediate-temperature coolant circulating through the first
coolant circuit C1 (intermediate-temperature coolant circuit) and
the refrigerant circulating through the refrigeration cycle 22.
[0731] In the thermal management system shown in FIGS. 72 and 73,
the coolant cooler 14 is adapted to cool the low-temperature
coolant by exchanging heat between the low-temperature coolant
circulating through the second coolant circuit C2 (low-temperature
coolant circuit) and the refrigerant circulating through the
refrigeration cycle 22.
[0732] In the thermal management system shown in FIG. 72, the
heater core 51 and the coolant pump (not shown) are disposed in the
first coolant circuit C1, whereas the radiator 13 and the coolant
pump (not shown) are disposed in the second coolant circuit C2.
[0733] In the thermal management system shown in FIG. 73, the
radiator 13 and the coolant pump (not shown) are disposed in the
first coolant circuit C1, whereas the cooler core 18 and the
coolant pump (not shown) are disposed in the second coolant circuit
C2.
[0734] The coolant cooler 14 and condenser 50 in the thermal
management system shown in FIGS. 72 and 73 can be integrated
together, like the first embodiment.
[0735] The coolant cooler 14, condenser 50, and expansion valve 25
of the above-mentioned seventh embodiment can also be applied to a
thermal management system shown in FIGS. 72 and 73. The coolant
cooler 14, condenser 50, and expansion valve 25 in the thermal
management system shown in FIGS. 72 and 73 can be integrated
together, like the seventh embodiment.
[0736] (13) The above-mentioned embodiments may be appropriately
combined together within the realm of possibility.
* * * * *