U.S. patent application number 12/927741 was filed with the patent office on 2011-05-26 for air conditioner for vehicle.
This patent application is currently assigned to DENSO CORPORATION. Invention is credited to Nobuharu Kakehashi, Manabu Maeda, Michio Nishikawa, Koji Ota.
Application Number | 20110120146 12/927741 |
Document ID | / |
Family ID | 43972628 |
Filed Date | 2011-05-26 |
United States Patent
Application |
20110120146 |
Kind Code |
A1 |
Ota; Koji ; et al. |
May 26, 2011 |
Air Conditioner for vehicle
Abstract
An air conditioner for a vehicle includes first and second
heating heat exchangers disposed to heat air by using a cooling
fluid for cooling an engine as a heat source, a heater disposed to
heat the cooling fluid flowing to the second heating heat
exchanger, and a controller that outputs an operation request
signal to the engine when a temperature of the cooling fluid is
lower than a predetermined temperature. The first and second
heating heat exchangers are arranged in parallel with respect to a
flow direction of the cooling fluid. In the air conditioner, the
controller controls a flow amount of the cooling fluid flowing into
the second heating heat exchanger to be, smaller than a flow amount
of the cooling fluid flowing into the first heating heat exchanger
when the heater heats the cooling fluid flowing to the second
heating heat exchanger.
Inventors: |
Ota; Koji; (Kariya-city,
JP) ; Maeda; Manabu; (Nagoya-city, JP) ;
Nishikawa; Michio; (Obu-city, JP) ; Kakehashi;
Nobuharu; (Toyoake-city, JP) |
Assignee: |
DENSO CORPORATION
Kariya-city
JP
|
Family ID: |
43972628 |
Appl. No.: |
12/927741 |
Filed: |
November 22, 2010 |
Current U.S.
Class: |
62/3.3 ; 165/59;
165/64 |
Current CPC
Class: |
B60H 1/03 20130101; F25B
21/02 20130101; B60H 1/00885 20130101 |
Class at
Publication: |
62/3.3 ; 165/59;
165/64 |
International
Class: |
F25B 21/02 20060101
F25B021/02; F24F 7/007 20060101 F24F007/007; F25B 29/00 20060101
F25B029/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 25, 2009 |
JP |
2009-267179 |
Mar 5, 2010 |
JP |
2010-49178 |
Mar 5, 2010 |
JP |
2010-49179 |
Claims
1. An air conditioner for a vehicle provided with a driving unit
for a vehicle traveling, the air conditioner comprising: first and
second heating heat exchangers disposed to heat air to be blown
into a vehicle compartment by using a cooling fluid for cooling the
driving unit as a heat source, the second heating heat exchanger
being arranged downstream of the first heating heat exchanger in an
air flow to heat air after passing through the first heating heat
exchanger; a heater disposed to heat the cooling fluid flowing to
the second heating heat exchanger, in the first and second heating
heat exchangers; and a controller for controlling a temperature of
air to be blown into the vehicle compartment, the controller
outputs an operation request signal to the driving unit when a
temperature of the cooling fluid is lower than a predetermined
temperature, wherein the first and second heating heat exchangers
are arranged in parallel with respect to a flow direction of the
cooling fluid, and the controller controls a flow amount of the
cooling fluid flowing into the second heating heat exchanger to be
smaller than a flow amount of the cooling fluid flowing into the
first heating heat exchanger when the heater heats the cooling
fluid flowing to the second heating heat exchanger.
2. The air conditioner according to claim 1, wherein the first and
second heating heat exchangers are configured such that a flow
resistance of the cooling fluid flowing in the second heating heat
exchanger is higher than a flow resistance of the cooling fluid
flowing in the first heating heat exchanger.
3. The air conditioner according to claim 1, further comprising a
flow adjustment unit that is configured to reduce the flow amount
of the cooling fluid flowing into the second heating heat exchanger
when the heater is turned on to heat the cooling fluid flowing into
the second heating heat exchanger, as compared with that when the
heater is turned off.
4. The air conditioner according to claim 1, further comprising a
sensible heat exchanger that is configured to move heat from the
cooling fluid downstream of the second heating heat exchanger to
the cooling fluid upstream of the heater.
5. The air conditioner according to claim 1, wherein the driving
unit includes an electrical motor for a vehicle traveling, and the
heater is an electrical heater which uses a high-voltage electrical
source for supplying electrical power to the electrical motor, as
an electrical source.
6. The air conditioner according to claim 1, wherein the heater is
a heat generator, which is mounted to the vehicle separately from
the driving unit, and generates heat when being operated.
7. The air conditioner according to claim 6, wherein the heat
generator is an inverter which converts an electrical current
supplied to the electrical motor.
8. An air conditioner for a vehicle provided with a driving unit
for a vehicle traveling, the air conditioner comprising: a heating
heat exchanger disposed to heat air to be blown into a vehicle
compartment by using a cooling fluid for cooling the driving unit
as a heat source; a controller for controlling a temperature of air
to be blown into the vehicle compartment, the controller outputs an
operation request signal to the driving unit when a temperature of
the cooling fluid is lower than a predetermined temperature; a heat
absorbing portion configured to absorb heat from the cooling fluid;
a heat radiating portion configured to radiate heat to the cooling
fluid; and a pump portion configured to pump heat from the heat
absorbing portion to the heat radiation portion.
9. The air conditioner according to claim 8, wherein the pump
portion is a Peltier element that includes a heat absorbing surface
thermally connected to the heat absorbing portion, and a heat
radiating surface thermally connected to the heat radiating
portion, and the Peltier element absorbs heat from the heat
absorbing surface and radiates heat from the heat radiating surface
when direct current is applied to the Peltier element.
10. The air conditioner according to claim 8, wherein the heating
heat exchanger is a heat exchanger in which the cooling fluid
flowing therein is heat exchanged with air passing therethrough so
as to heat air, the heat absorbing portion is disposed downstream
of the heating heat exchanger in a flow direction of the cooling
fluid, to absorb heat from the cooling fluid flowing out of the
heating heat exchanger, and the heat radiation portion is disposed
upstream of the heating heat exchanger in the flow direction of the
cooling fluid, to radiate heat to the cooling fluid flowing into
the heating heat exchanger.
11. The air conditioner according to claim 10, wherein the heating
heat exchanger includes a first, heater core for heating air, and a
second heater core disposed to heat air after passing through the
first heater core, the heat absorbing portion is disposed
downstream of the second heater core in the flow direction of the
cooling fluid to absorb heat from the cooling fluid flowing out of
the second heater core, and the heat radiating portion is disposed
upstream of the second heater core in the flow direction of the
cooling fluid to radiate heat to the cooling fluid flowing into the
second heater core.
12. The air conditioner according to claim 11, wherein the first
and second heater cores are arranged in parallel with respect to
the flow direction of the cooling fluid.
13. The air conditioner according to claim 10, further comprising a
heat exchanger disposed to perform heat exchange between the
cooling fluid before flowing into the heat radiating portion, and
the cooling fluid before flowing into the heat absorbing portion at
a position downstream of the second heater core in the flow
direction of the cooling fluid.
14. The air conditioner according to claim 10, further comprising a
first bypass passage through which a part of the cooling fluid
before flowing into the heat radiating portion is introduced into
the heat absorbing portion without performing heat exchange with
air in the second heater core.
15. The air conditioner according to claim 10, further comprising a
second bypass passage through which a part of the cooling fluid
upstream of the heat radiating portion is introduced to the driving
unit while bypassing the heat radiating portion and the heat
absorbing portion.
16. The air conditioner according to claim 8, further comprising: a
first fluid circuit in which the cooling fluid of the driving unit
is circulated; and a second fluid circuit independently provided
from the first fluid circuit, in which a fluid heated by the
cooling fluid is circulated to flow into the heating heat
exchanger.
17. An air conditioner for a vehicle having an internal combustion
engine, the air conditioner comprising a heating heat exchanger
configured to heat air to be blown into a vehicle compartment, by
using a first fluid for cooling the internal combustion engine and
a second fluid having a temperature higher than the first fluid, as
a heat source, wherein the heating heat exchanger includes a first
heat exchanging portion in which the first fluid or a mixture of
the first fluid and the second fluid flows, and a second heat
exchanging portion in which a fluid that is mainly the second fluid
and has a temperature higher than a fluid flowing into the first
heat exchanging portion flows, and the first heat exchanging
portion and the second heat exchanging portion are integrated to
form a space therebetween.
18. The air conditioner according to claim 17, wherein the second
heat exchanging portion is arranged downstream of the first heat
exchanging portion in an air flow direction.
19. The air conditioner according to claim 17, wherein the first
heat exchanging portion and the second heat exchanging portion are
arranged in parallel with respect to an air flow direction.
20. The air conditioner according to claim 17, wherein the first
heat exchanging portion has a heat exchanging area in which air is
heat exchanged with the fluid, and the heat exchanging area of the
first heat exchanging portion is larger than the heat exchanging
area of the second heat exchanging portion.
21. The air conditioner according to claim 17, wherein the first
heat exchanging portion and the second heat exchanging portion are
arranged such that a flowing amount of the fluid flowing in the
first heat exchanging portion is larger than that flowing in the
second heat exchanging portion.
22. The air conditioner according to claim 17, wherein the first
heat exchanging portion and the second heat exchanging portion are
configured to have respective fluid passages that are independent
from each other.
23. The air conditioner according to claim 17, further comprising
an air conditioning case in which the first heat exchanging portion
and the second heat exchanging portion are disposed, the air
conditioning case has a first air outlet from which air only having
passed through the first heat exchanging portion is blown toward an
inner surface of a windshield of the vehicle, and a second air
outlet from which air having passed through the second heat
exchanging portion is blown toward a passenger in the vehicle
compartment.
24. The air conditioner according to claim 17, wherein the first
fluid is a cooling fluid for cooling a cylinder head of the
internal combustion engine, and the second fluid is a cooling fluid
for cooling a cylinder block of the internal combustion engine.
25. The air conditioner according to claim 17, wherein the first
fluid is a cooling fluid for cooling the internal combustion
engine, and the second fluid is a cooling fluid for cooling a heat
generation member that is an equipment mounted to the vehicle and
is different from the internal combustion engine.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is based on Japanese Patent Applications
No. 2009-267179 filed on Nov. 25, 2009, No. 2010-049178 filed on
Mar. 5, 2010, and No. 2010-049179 filed on Mar. 5, 2010, the
contents of which are incorporated herein by reference in its
entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to an air conditioner for a
vehicle.
BACKGROUND OF THE INVENTION
[0003] Conventionally, a vehicle air conditioner is provided with a
heating heat exchanger that heats air to be blown into a vehicle
compartment by using engine coolant as a heat source, for example,
as in Patent Document 1 (JP 2007-278624A) or Patent Document 2 (JP
2008-126820A).
[0004] In this kind vehicle air conditioner, when the temperature
of engine coolant is lower than a predetermined temperature, an
operation request signal is output to an engine, even in a vehicle
such as a hybrid vehicle or an idling-stop vehicle. In the vehicle
such as the hybrid vehicle or the idling-stop vehicle, the engine
stops in accordance with a vehicle traveling state. When the engine
stops, the temperature of the engine coolant becomes lower, and it
may be difficult to secure the heating capacity of air in the
heating heat exchanger by using the engine coolant as the heat
source. In this case, the engine is operated only for the air
conditioning, so as to obtain the heating capacity of air due to
the heating heat exchanger.
[0005] For example, in the vehicle air conditioner described in
Patent Document 1, heat is absorbed from air in a heat pump cycle,
and the engine coolant to be supplied to the heating heat exchanger
is heated by using the absorbed heat of the heat pump cycle.
[0006] In the vehicle air conditioner described in Patent Document
2, an auxiliary heater using a PTC element is located downstream of
the heating heat exchanger which heats air to be blown into the
vehicle compartment by using the engine coolant as a heat
source.
[0007] However, in the vehicle air conditioner where the operation
request signal is output to the engine when the temperature of the
engine coolant is lower than the predetermined temperature, fuel
consumption efficiency may be deteriorated:
[0008] Furthermore, when the temperature of the engine coolant is
low, the heat pump cycle may be operated instead of the engine
operation, as in Patent Document 1.
[0009] When the heat pump cycle is operated for heating the engine
coolant, energy is consumed by the operation of the heat pump
cycle, and thereby consumed energy consumed for the heating of the
engine coolant is increased.
[0010] Furthermore, when the temperature of the engine coolant is
low, an auxiliary heater such as a PTC heater may be operated to
directly heat air, instead of the engine operation, as in Patent
Document 2. However, when the auxiliary heater is located
downstream of the heating heat exchanger in an air flow, the
auxiliary heater becomes a resistance in the flow of air blown into
the vehicle compartment.
[0011] Alternatively, when the temperature of the engine coolant is
low, the engine coolant may be heated by using a heating means
other than the engine while the resistance of air blown into the
vehicle compartment is not increased.
[0012] However, in a case where the engine coolant is simply heated
by the heating means other than the engine, the heat quantity
without being heat-exchanged with air in the heating heat exchanger
may be radiated from the surface of the engine, and the heated
quantity may be uselessly consumed.
[0013] This problem may be caused not only in an air conditioner
for a vehicle provided with the engine, but also in an air
conditioner for a vehicle provided with a driving device other than
the engine, such as a fuel cell for traveling or an electrical
motor for traveling.
[0014] In the air conditioner for a fuel cell vehicle provided with
a fuel cell and an electrical motor, air to be blown into the
vehicle compartment is heated by using coolant of the fuel cell as
a heat source. In this case, when the temperature of the coolant of
the fuel cell is lower than a predetermined temperature, the fuel
cell is operated to generate an electrical power, and thereby
energy consumed in the fuel cell becomes larger.
[0015] Furthermore, in a vehicle air conditioner described in
Patent Document 3 (U.S. Pat. No. 5,337,704), as a coolant passage
inside of an engine, a cylinder head passage for cooling a cylinder
head and a cylinder block passage for cooling a cylinder block are
used. The coolant passing through the cylinder head passage flows
through a single heating heat exchanger, and is used as a heat
source for a heating of a vehicle compartment.
[0016] In a vehicle air conditioner described in Patent Document 4
(EP 1008471A), two heating heat exchangers are provided for heating
air, such that coolant flowing out of a single coolant outlet of an
engine is branched and flows respectively into the two heating heat
exchanger.
[0017] Generally, in order to reduce the size of the engine mounted
to a vehicle while maintaining a required output of an engine, a
compression ratio is increased, or a changing pressure is increased
in the engine with a supercharger. However, if the compression
ratio is increased or the charging pressure is increased in the
engine with the supercharger, knocking may be caused. Thus, it may
be considered to cool the cylinder head, in order to improve
knocking-preventing performance.
[0018] On the other hand, it is necessary to keep the temperature
of the cylinder block to be higher than a predetermined
temperature, in order to reduce a friction of the cylinder block in
the engine. Accordingly, the cylinder head passage and the cylinder
block passage may be provided as the coolant passage of the engine,
such that the flow amount of the coolant flowing in the cylinder
head passage is larger than the flow amount of the coolant flowing
in the cylinder block passage, as in Patent Document 3.
[0019] However, in this case, the temperature of the coolant after
cooling the cylinder head may be lower than the lowest temperature
required for the heating, and the temperature of air to be blown
into the vehicle compartment cannot be sufficiently increased by
using the coolant after passing through the cylinder head as the
heat source.
[0020] Furthermore, in a vehicle where an engine efficiency is
improved thereby reducing heat-generating amount of the engine, or
in a hybrid vehicle, it is difficult to sufficiently heat air by
using the engine coolant as the heat source.
[0021] To increase the temperature of the coolant as the heat
source of the heating, a high-temperature hot water or a
high-temperature fluid may be mixed with the coolant as the heat
source of the heating. However, in this case, it is difficult to
effectively use the heat quantity in the entire system.
[0022] In view of the above problems, it is an object of the
present invention to provide a vehicle air conditioner which can
effectively reduce consumed energy.
[0023] It is another object of the present invention to provide a
vehicle air conditioner which can effectively perform heating
operation while reducing consumed energy.
[0024] It is another object of the present application to provide
an air conditioner including a heating heat exchanger provided with
first and second heat exchanging portions, which can heat air to be
blown into a vehicle compartment, by effectively using both a first
fluid for cooling an internal combustion engine and a second fluid
having a temperature higher than the first fluid.
[0025] According to an aspect of the present invention, an air
conditioner for a vehicle provided with a driving unit for a
vehicle traveling, includes: first and second heating heat
exchangers disposed to heat air to be blown into a vehicle
compartment by using a cooling fluid for cooling the driving unit
as a heat source; a heater disposed to heat the cooling fluid
flowing to the second heating heat exchanger in the first and
second heating heat exchangers; and a controller for controlling a
temperature of air to be blown into the vehicle compartment. The
controller outputs an operation request signal to the driving unit
when a temperature of the cooling fluid is lower than a
predetermined temperature. Furthermore, the second heating heat
exchanger are arranged downstream of the first heating heat
exchanger in an air flow to heat air after passing through the
first heating heat exchanger, and the first and second heating heat
exchangers are arranged in parallel with respect to a flow
direction of the cooling fluid. In the vehicle air conditioner, the
controller controls a flow amount of the cooling fluid flowing into
the second heating heat exchanger to be smaller than a flow amount
of the cooling fluid flowing into the first heating heat exchanger
when the heater heats the cooling fluid flowing to the second
heating heat exchanger.
[0026] Accordingly, the temperature of the cooling fluid flowing
into the second heating heat exchanger can be effectively increased
by the heater, it is unnecessary to increase the temperature of the
cooling fluid more than a necessary temperature required for the
heating of air, by operation of the driving unit. Thus, it is
possible to set a predetermined temperature, which is a basic
temperature for determining whether an operation request signal is
output to the driving unit, to be lower. Thus, operation frequency
of the driving unit can be reduced, thereby reducing energy
consumed in the driving unit. Furthermore, because only the cooling
fluid flowing toward the second heating heat exchanger is heated
between the first and second heating heat exchangers, the consumed
energy consumed for heating the cooling fluid can be reduced. In
addition, in the vehicle air conditioner, because the controller
controls a flow amount of the cooling fluid flowing into the second
heating heat exchanger to be smaller than a flow amount of the
cooling fluid flowing into the first heating heat exchanger when
the heater heats the cooling fluid flowing to the second heating
heat exchanger, a ratio of heat radiation from the cooling fluid in
the second heat exchanger to the heat quantity due to the heater in
the cooling fluid can be effectively increased. As a result, it can
restrict the heat quantity without being heat-exchanged with air in
the second heating heat exchanger from being radiated from the
surface of the driving unit, thereby effectively using the heat
quantity due to the heating of the heater.
[0027] For example, the first and second heating heat exchangers
may be configured such that a flow resistance of the cooling fluid
flowing in the second heating heat exchanger is higher than a flow
resistance of the cooling fluid flowing in the first heating heat
exchanger.
[0028] Furthermore, a flow adjustment unit may be provided to
reduce the flow amount of the cooling fluid flowing into the second
heating heat exchanger when the heater is turned on to heat the
cooling fluid flowing into the second heating heat exchanger, as
compared with that when the heater is turned off.
[0029] Alternatively/Further, the air conditioner may be provided
with a sensible heat exchanger that is configured to move heat from
the cooling fluid downstream of the second heating heat exchanger
to the cooling fluid upstream of the heater.
[0030] The driving unit may include an electrical motor for a
vehicle traveling, and the heater may be an electrical heater which
uses a high-voltage electrical source for supplying electrical
power to the electrical motor, as an electrical source.
Alternatively, the heater may be a heat generator, which is mounted
to the vehicle separately from the driving unit, and generates heat
when being operated. For example, the heat generator is an inverter
which converts an electrical current supplied to the electrical
motor.
[0031] According to another aspect of the present invention, an air
conditioner for a vehicle provided with a driving unit for a
vehicle traveling, includes: a heating heat exchanger disposed to
heat air to be blown into a vehicle compartment by using a cooling
fluid for cooling the driving unit as a heat source; a controller
for controlling a temperature of air to be blown into the vehicle
compartment, the controller outputs an operation request signal to
the driving unit when a temperature of the cooling fluid is lower
than a predetermined temperature; a heat absorbing portion
configured to absorb heat from the cooling fluid; a heat radiating
portion configured to radiate heat to the cooling fluid; and a pump
portion configured to pump heat from the heat absorbing portion to
the heat radiation portion. Generally, the cooling fluid has a
temperature higher than outside air in winter. Thus, it is compared
with a case where the pump portion pumps heat from outside air,
heat radiation amount to the cooling fluid (heat source) can be
increased, thereby reducing consumed energy in the pump
portion.
[0032] For example, the pump portion is a Peltier element that
includes a heat, absorbing surface thermally connected to the heat
absorbing portion, and a heat radiating surface thermally connected
to the heat radiating portion. In this case, the Peltier element
absorbs heat from the heat absorbing surface and radiates heat from
the heat radiating surface when direct current is applied to the
Peltier element.
[0033] The heating heat exchanger may be a heat exchanger in which
the cooling fluid flowing therein is heat exchanged with air
passing therethrough so as to heat air. In this case, the heat
absorbing portion is disposed downstream of the heating heat
exchanger in a flow direction of the cooling fluid, to absorb heat
from the cooling fluid flowing out of the heating heat exchanger,
and the heat radiation portion is disposed upstream of the heating
heat exchanger in the flow direction of the cooling fluid, to
radiate heat to the cooling fluid flowing into the heating heat
exchanger. Furthermore, the heating heat exchanger may include a
first heater core for heating air, and a second heater core
disposed to heat air after passing through the first heater core.
In this case, the heat absorbing portion is disposed downstream of
the second heater core in the flow direction of the cooling fluid
to absorb heat from the cooling fluid flowing out of the second
heater core, and the heat radiating portion is disposed upstream of
the second heater core in the flow direction of the cooling fluid
to radiate heat to the cooling fluid flowing into the second heater
core. Here, the first and second heater cores may be arranged in
parallel with respect to the flow, direction of the cooling fluid,
or may be arranged in series in the flow direction of the cooling
fluid.
[0034] Furthermore, a heat exchanger may be disposed to perform
heat exchange between the cooling fluid before flowing into the
heat radiating portion, and the cooling fluid before flowing into
the heat absorbing portion at a position downstream of the second
heater core in the flow direction of the cooling fluid.
[0035] A first bypass passage may be provided such that a part of
the cooling fluid before flowing into the heat radiating portion is
introduced into the heat absorbing portion without performing heat
exchange with air in the second heater core, via the first bypass
passage. Furthermore/Alternatively, a second bypass passage may be
provided such that a part of the cooling fluid upstream of the heat
radiating portion is introduced to the driving unit while bypassing
the heat radiating portion and the heat absorbing portion, via the
second bypass passage.
[0036] In the air conditioner, a first fluid circuit, in which the
cooling fluid of the driving unit is circulated, may be
independently provided from a second fluid circuit in which a fluid
heated by the cooling fluid is circulated to flow into the heating
heat exchanger.
[0037] According to another aspect of the present invention, an air
conditioner for a vehicle with an internal combustion engine
includes a heating heat exchanger configured to heat air to be
blown into a vehicle compartment, by using a first fluid for
cooling the internal combustion engine and a second fluid having a
temperature higher than the first fluid, as a heat source.
Furthermore, the heating heat exchanger includes a first heat
exchanging portion in which the first fluid or a mixture of the
first fluid and the second fluid flows, and a second heat
exchanging portion in which a fluid that is mainly the second fluid
and has a temperature higher than a fluid flowing into the first
heat exchanging portion flows. In addition, the first heat
exchanging portion and the second heat exchanging portion are
integrated to form a space therebetween. Thus, air can be heated in
the first heat exchanging portion by using a low temperature fluid
at least including the first fluid for cooling the internal
combustion engine as the heat source, and air can be heated in the
second heat exchanging portion by using a high temperature fluid
that is mainly the second fluid as the heat source. Accordingly, as
compared with a case where air is heated by using the mixture of
the first fluid and the second fluid as a heat source, the heat
quantity of the second fluid can be effectively used, and thereby
the temperature of air after being heated in the second heat
exchanging portion can be improved.
[0038] For example, the second heat exchanging portion may be
arranged downstream of the first heat exchanging portion in an air
flow direction. Furthermore/Alternatively, the first heat
exchanging portion and the second heat exchanging portion may be
arranged in parallel with respect to an air flow direction.
[0039] The first heat exchanging portion may have a heat exchanging
area in which air is heat exchanged with the fluid, and the heat
exchanging area of the first heat exchanging portion may be larger
than the heat exchanging area of the second heat exchanging
portion.
[0040] Alternatively/Furthermore, the first heat exchanging portion
and the second heat exchanging portion may be arranged such that a
flowing amount of the fluid flowing in the first heat exchanging
portion is larger than that flowing in the second heat exchanging
portion. Furthermore, the first heat exchanging portion and the
second heat exchanging portion may be configured to have respective
fluid passages that are independent from each other.
[0041] The air conditioner may be provided with an air conditioning
case in which the first heat exchanging portion and the second heat
exchanging portion are disposed. In this case, the air conditioning
case may be provided with a first air outlet from which air only
having passed through the first heat exchanging portion is blown
toward an inner surface of a windshield of the vehicle, and a
second air outlet from which air having passed through the second
heat exchanging portion is blown toward a passenger in the vehicle
compartment.
[0042] In the air conditioner, the first fluid may be a cooling
fluid for cooling a cylinder head of the internal combustion
engine, and the second fluid may be a cooling fluid for cooling a
cylinder block of the internal combustion engine. Alternatively,
the first fluid may be a cooling fluid for cooling the internal
combustion engine, and the second fluid may be a cooling fluid for
cooling a heat generation member that is an equipment mounted to
the vehicle and is different from the internal combustion
engine.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] Other objects, features and advantages of the present
invention will become more apparent from the following description
made with reference to the accompanying drawings, in which like
parts are designated by like reference numbers and in which:
[0044] FIG. 1 is a schematic diagram showing an air conditioner for
a vehicle according to a first embodiment of the invention;
[0045] FIG. 2 is a block diagram showing an electric controller of
the air conditioner for a vehicle in FIG. 1;
[0046] FIG. 3 is a flowchart showing a control performed by the
electric controller of the air conditioner, shown in FIG. 2;
[0047] FIG. 4 is a flowchart showing a detail control at step S4 of
FIG. 3;
[0048] FIG. 5 is a schematic diagram showing an air conditioner for
a vehicle according to a second embodiment of the invention;
[0049] FIG. 6 is a schematic diagram showing an air conditioner for
a vehicle according to a third embodiment of the invention;
[0050] FIG. 7 is a schematic diagram showing an air conditioner for
a vehicle according to a fourth embodiment of the invention;
[0051] FIG. 8 is a schematic diagram showing an air conditioner for
a vehicle according to a fifth embodiment of the invention;
[0052] FIG. 9 is a schematic diagram showing an air conditioner for
a vehicle according to a sixth embodiment of the invention;
[0053] FIG. 10 is a schematic diagram showing an air conditioner
for a vehicle according to a seventh embodiment of the
invention;
[0054] FIG. 11 is a schematic diagram showing an air conditioner
for a vehicle according to an eighth embodiment of the
invention;
[0055] FIG. 12 is a schematic diagram showing an air conditioner
for a vehicle according to a ninth embodiment of the invention;
[0056] FIG. 13 is a schematic diagram showing an air conditioner
for a vehicle according to a tenth embodiment of the invention;
[0057] FIG. 14 is a schematic diagram showing an air conditioner
for a vehicle according to an eleventh embodiment of the
invention;
[0058] FIG. 15 is a schematic diagram showing an air conditioner
for a vehicle according to a twelfth embodiment of the
invention;
[0059] FIG. 16 is a block diagram showing an electric controller of
the air conditioner for a vehicle in the twelfth embodiment;
[0060] FIG. 17 is a flowchart for determining ON/OFF operation of
an electrical heater, according to the twelfth embodiment of the
invention;
[0061] FIG. 18 is a schematic diagram showing an air conditioner
for a vehicle according to a thirteenth embodiment of the
invention;
[0062] FIG. 19 is a schematic diagram showing an air conditioner
for a vehicle according to a fourteenth embodiment of the
invention;
[0063] FIG. 20 is a perspective view showing first and second
heater cores according to a fifteenth embodiment of the
invention;
[0064] FIG. 21 is a schematic diagram showing an air conditioner
for a vehicle according to a sixteenth embodiment of the
invention;
[0065] FIG. 22 is a side view showing a heating heat exchanger
according to the sixteenth embodiment;
[0066] FIG. 23 is a front view showing the heating heat exchanger
according to the sixteenth embodiment;
[0067] FIG. 24 is a graph showing a temperature variation in air
passing through the first and second heater cores of the heating
heat exchanger according to a sixteenth embodiment of the
invention;
[0068] FIGS. 25A, 25B and 25C are graphs showing a heat loss of
coolant from an engine surface, an average temperature of a
combustion chamber of the engine and an actual fuel consumption
rate, according to the sixteenth embodiment and a comparison
example (second comparison example);
[0069] FIG. 26 is a side view showing a heating heat exchanger
according to a seventeenth embodiment of the invention;
[0070] FIG. 27 is a side view showing a heating heat exchanger
according to an eighteenth embodiment of the invention;
[0071] FIG. 28 is a side view showing a heating heat exchanger
according to a nineteenth embodiment of the invention;
[0072] FIG. 29 is a front view showing a heating heat exchanger
according to the nineteenth embodiment;
[0073] FIG. 30 is a side view showing a heating heat exchanger
according to a twentieth embodiment of the invention;
[0074] FIG. 31 is a front view showing a heating heat exchanger
according to the twentieth embodiment;
[0075] FIG. 32 is a side view showing a heating heat exchanger
according to a twenty-first embodiment of the invention; and
[0076] FIG. 33 is a schematic diagram showing an air conditioner
for a vehicle according to a twenty-second embodiment of the
invention.
EMBODIMENTS
[0077] Embodiments for carrying out the present invention will be
described hereafter referring to drawings. In the embodiments, a
part that corresponds to a matter described in a preceding
embodiment may be assigned with the same reference numeral, and
redundant explanation for the part may be omitted. When only a part
of a configuration is described in an embodiment, another preceding
embodiment may be applied to the other parts of the configuration.
The parts may be combined even if it is not explicitly described
that the parts can be combined. The embodiments may be partially
combined even if it is not explicitly described that the
embodiments can be combined, provided there is no harm in the
combination.
First Embodiment
[0078] A first embodiment of the present invention will be
described with reference to FIGS. 1 to 4.
[0079] FIG. 1 is a schematic diagram showing an air conditioner 1
for a vehicle according to the present embodiment of the invention,
and FIG. 2 is a block diagram showing an electric controller of the
air conditioner for a vehicle in the present embodiment. In the
present embodiment, the air conditioner 1 for a vehicle of the
invention is mounted to a so-called hybrid car which obtains a
driving force for a vehicle traveling from an internal combustion
engine (engine) EG and an electric motor for traveling. Thus, the
engine EG is an example of a driving device for obtaining a driving
force for a vehicle running in the invention.
[0080] In the hybrid vehicle of the embodiment, the engine EG is
operated or stopped in accordance with a traveling load of the
vehicle. Thus, the hybrid vehicle can be switched to a traveling
state in which the vehicle is traveled by using driving force from
both of the engine EG and the electrical motor for traveling, or a
traveling state (i.e., EV traveling state) in which the vehicle is
traveled only by using the electrical motor for traveling while the
engine is stopped. Thus, in the hybrid vehicle, fuel consumption
can be improved as compared with a vehicle driven by only the
engine EG.
[0081] The air conditioner 1 for a vehicle is provided with an
interior air conditioning unit 10 shown in FIG. 1, and an air
conditioning controller 60 (A/C ECU) shown in FIG. 2.
[0082] The interior air conditioning unit 10 is located inside of
an instrument panel (i.e., dash panel) positioned at the frontmost
portion in the vehicle compartment. The interior air-conditioning
unit 10 includes an air conditioning casing 11 forming an outer
shell and defining an air passage. In the air conditioning casing
11, a blower 12, an evaporator 13, a first heater core 14, a second
heater core 15 and the like are disposed.
[0083] The casing 11 defines the air passage through which air
flows into the vehicle compartment. The casing 11 is made of a
resin (e.g., polypropylene) having a suitable elasticity and being
superior in the strength. An inside/outside air switching box 20 is
located in the casing 11 at the most upstream side to selectively
introduce inside air or/and outside air into the casing 11.
[0084] More specifically, the inside/outside air switching box 20
is provided with an inside air introduction port 21 for introducing
inside air into the casing 11, and an outside air introduction port
22 for introducing outside air into the casing 11. An
inside/outside air switching door 23 is disposed in the
inside/outside air switching box 20 to continuously adjust open
areas of the inside air introduction port 21 and the outside air
introduction port 22. Therefore, the inside/outside air switching
door 23 can adjust a ratio between a flow amount of inside air
(i.e., air inside the vehicle compartment) introduced from the
inside air introduction port 21 and a flow amount of outside air
(i.e., air outside the vehicle compartment). The inside/outside air
switching door 23 is driven by an electrical actuator 71, and
operation of the electrical actuator 71 is controlled by a control
signal output from the air conditioning controller 60.
[0085] The blower 12 is disposed in the casing 31 at a downstream
air side of the inside/outside air switching box 20, to blow air
drawn via the inside/outside air switching box 20 toward the
interior of the vehicle compartment. The blower 12 is an electrical
blower having a centrifugal multi-blade fan (e.g., sirocco fan) 12a
and an electrical motor 12b, for example. In this case, the
centrifugal multi-blade fan 12a is driven by the electrical motor
12b, and the rotational speed (air blowing amount) of the
electrical motor 12b is controlled by a control voltage output from
the air conditioning controller 60.
[0086] The evaporator 13 is disposed in the casing 11 at a
downstream air side of the blower 12 to cross all the air passage
area in the casing 11. The evaporator 13 is a cooling heat
exchanger in which refrigerant passing therein is heat-exchanged
with air blown by the blower 12 to cool the blown air. The
evaporator 12 is one component in a refrigerant cycle. The
refrigerant cycle includes, for example, a compressor, a condenser,
a gas-liquid separator and an expansion valve, in addition to the
evaporator 13, which are generally known.
[0087] At a downstream air side of the evaporator 13, the air
passage of the casing 31 is provided with a first air passage 16
through which air after passing through the evaporator 13 flows, a
second air passage 17 used as a cool air bypass passage through
which air after passing through the evaporator 13 flows while
bypassing the first and second heater core 14, 15, and a mixing
space 18 in which air from the first air passage 16 and air from
the second air passage 17 are mixed.
[0088] In the first air passage 16, the first and second heater
cores 14 and 15 are arranged, so that air dehumidified and cooled
by the evaporator 13 flows through the first and second heater
cores 14 and 15 in this order through the first air passage 16. The
first heater core 14 is a first heating heat exchanger configured
to perform heat exchange between engine coolant (hot water) heated
by heat of the vehicle engine EG and air after passing through the
evaporator 13. Thus, the first heat core 14 heats air after passing
through the evaporator 13 in the first air passage 16. The second
heater core 15 is a second heating heat exchanger configured to
perform heat exchange between engine coolant (hot water) and air
after passing through the first heater core 14. Thus, the second
heat core 15 further heats air after passing through the first
heater core 14 in the first air passage 16. For example, the engine
coolant is water, or a water solution including addition
component.
[0089] Specifically, a coolant circuit 30 is provided, so that
coolant is circulated between the first and second heater cores 14,
15 and the engine EG via the coolant circuit 30. The coolant
circuit 30 is provided with a coolant passage 31 adapted to the
first and second heater cores 14, 15, and a coolant passage 32
adapted to a radiator 41. The coolant passages 31, 32 are connected
to the engine EG in parallel with respect to a flow of the coolant
from the engine EG.
[0090] The coolant passage 31 for the first and second heater cores
14, 15 is provided with a branch point 31a, a join point 31b, and
first and second coolant passages 33, 34. The coolant flowing out
of the engine EG is branched at the branch portion 31a into the
first coolant passage 33 and the second coolant passage 34, and is
joined at the join point 31b: The first heater core 14 is located
in the first coolant passage 33 so that the coolant flowing into
the first coolant passage 33 flows through the first heater core
14. The second heater core 15 is located in the second coolant
passage 34 so that the coolant flowing into the second coolant
passage 34 flows through the second heater core 15. The coolant
having passed through the first and second heater cores 14, 15
respectively is joined at the join point 31b, and returns to the
engine EG. Thus, the first and second heater cores 14, 15 are
arranged in parallel with respect to the flow of the engine
coolant.
[0091] As shown in FIG. 1, a heat-absorption side heat exchanger 51
is located in the second coolant passage 34 at a downstream side of
the second heater core 15 in the coolant flow, and a heat-radiation
side heat exchanger 52 is located in the second coolant passage 34
at an upstream side of the second heater core 15 in the coolant
flow. A Peltier element 53 is disposed outside of the second
coolant passage 34, at a position between the heat-absorption side
heat exchanger 51 and the heat-radiation side heat exchanger
52.
[0092] The heat-absorption side heat exchanger 51 is a heat
exchanger for absorbing heat from the coolant, and the
heat-radiation side heat exchanger 52 is a heat exchanger for
radiating heat to the coolant. The heat-absorption side heat
exchanger 51 and the heat-radiation side heat exchanger 52 are
configured such that the flow direction of the coolant flowing
through the heat-absorption side heat exchanger 51 is opposite to
the flow direction of the coolant flowing through the
heat-radiation side heat exchanger 52. That is, the coolant
reversely flows through the heat-absorption side heat exchanger 51
and the heat-radiation side heat exchanger 52.
[0093] The Peltier element 53 is provided with a heat absorbing
surface thermally connected to the heat-absorption side heat
exchanger 51, and a heat radiating surface thermally connected to
the heat-radiation side heat exchanger 52. When electrical current
is applied to the Peltier element 53, heat is absorbed via the heat
absorbing surface, and heat is radiated via the heat radiating
surface. Thus, the Peltier element 53 is a heat pump system for
pumping heat from the heat absorbing surface of the Peltier element
53 to the heat radiating surface of the Peltier element 53. The
pumped heat quantity is adjusted by adjusting the electrical
current applied to the Peltier element 53.
[0094] Because the heat-absorption side heat exchanger 51 and the
heat-radiation side heat exchanger 52 are thermally connected
respectively to the heat absorbing surface and the heat radiating
surface of the Peltier element 53, heat is transmitted
therebetween. Thus, when the direct current flows the Peltier
element 53, the Peltier element 53 absorbs heat from the coolant at
a coolant outlet side of the second heater core 15 via the
heat-absorption side heat exchanger 51, and radiates heat to the
coolant at a coolant inlet side of the second heater core 15 via
the heat-radiation side heat exchanger 52. The operation of the
Peltier element 53 is controlled based on the control current
output from the air conditioning controller 60. Specifically, an
electrical power turning on/off operation of the Peltier element 53
and an electrical current to be applied to the Peltier element 53
in the electrical power turning-on operation are controlled based
on the control signal output from the air conditioning controller
60.
[0095] A thermostat 42 is located in the coolant circuit 30 at a
coolant inlet side of the engine EG in the coolant circuit 30. A
flow amount of the coolant flowing into the coolant passage 31 for
the first and second heater cores 14, 15 and a flow amount of the
coolant flowing into the coolant passage 32 for the radiator 41 are
adjusted by the thermostat 42. An electrical water pump 43 is
disposed in the coolant circuit 30 so that the coolant circulates
in the coolant circuit 30. The operation of the water pump 43 can
be controlled such that the water pump 43 is operated even when the
engine EG is stopped. The water pump 43 may be operated by the
power from the engine EG. In this case, the water pump 43 is also
stopped when the engine EG stops.
[0096] A first coolant temperature sensor 65 is located at a
coolant outlet side of the engine EG, to detect the temperature of
the coolant flowing out of the engine EG. A second coolant
temperature sensor 66 is located between the heat-radiation side
heat exchanger 52 and the second heater core 15 in the coolant
circuit 30, to detect the temperature of the coolant flowing into
the second core 15.
[0097] On the other hand, cool air having passed through the
evaporator 13 flows into the mixing space 18 through the second air
passage 17 used as the cool air bypass passage while bypassing the
first and second heater cores 14 and 15. Thus, the temperature of
air (i.e., conditioned air) mixed in the mixing space 18 is changed
by adjusting a ratio between a flow amount of air passing through
the first air passage 16 and a flow amount of air passing through
the second air passage 17.
[0098] In the present embodiment, an air mix door 19 is located on
a downstream air side of the evaporator 13 at an upstream air side
of the first air passage 16 and the second air passage 17, and is
configured to continuously change a ratio between a flow amount of
air passing through the first air passage 16 and a flow amount of
air passing through the second air passage 17.
[0099] The air mix door 19 is used as a temperature adjusting unit
that adjusts the air temperature in the mixing space 18 so as to
adjust the temperature of conditioned air to be blown into the
vehicle compartment. The air mix door 19 is driven by an electrical
actuator 72, and operation of the electrical actuator 72 for the
air mix door 19 is controlled by a control signal output from the
air conditioning controller 60.
[0100] Furthermore, at the most downstream air side, the casing 11
is provided with plural opening portions 24, 25, 26 from which
conditioned air of the mixing space 18 is blown into the vehicle
compartment that is a space to be air-conditioned. For example, the
plural opening portions 24, 25, 26 include a defroster opening
portion 24, a face opening portion 25 and a foot opening portion
26.
[0101] A defroster duct (not shown) is connected to the defroster
opening portion 24, such that conditioned air is blown toward an
inner surface of a front windshield of the vehicle from a defroster
air outlet provided at a downstream end of the defroster duct. A
face duct (not shown) is connected to the face opening portion 25,
such that conditioned air is blown toward an upper side of a
passenger in the vehicle compartment from a face air outlet
provided at a downstream end of the face duct. A foot duct (not
shown) is connected to the foot opening portion 26, such that
conditioned air is blown toward a lower side of a passenger in the
vehicle compartment from a foot air outlet provided at a downstream
end of the foot duct.
[0102] Air outlet mode doors for selectively switching an air
outlet mode are provided in the casing 11. The air outlet mode
doors include a defroster door 24 for opening and closing the
defroster opening portion 24, a face door 25a for opening and
closing the face opening portion 25, and a foot door 26a for
opening and closing the foot opening portion 26. The outlet mode
doors 24a, 25a, 26a are driven by an electrical actuator 73, and
operation of the electrical actuator 73 for the outlet mode doors
24a, 25a, 26a is controlled by a control signal output from the air
conditioning controller 60.
[0103] Next, an electrical control portion of the present
embodiment will be described with reference to FIG. 2. The air
conditioning controller 60 is configured by a very-known
microcomputer including CPU, ROM, RAM, etc., and a circumference
circuit of the microcomputer. The air conditioning controller 60
performs various calculations and processes based on control
programs stored in the ROM, and performs control operation of
various equipments connected to output of the air conditioning
controller 60. For example, operation of the blower 12, the
electrical actuators 71, 72, 73 and the Peltier element 53 is
controlled by the air conditioning controller 60.
[0104] Air conditioning sensor group is connected to an input side
of the air conditioning controller 60. For example, the air
conditioning sensor group includes an inside air sensor 61
configured to detect an inside air temperature Tr of the vehicle
compartment, an outside air sensor 62 configured to detect an
outside air temperature Tam, a solar radiation sensor 63 configured
to detect a solar radiation Ts entering into the vehicle
compartment, an evaporator temperature sensor 64 configured to
detect an air temperature TE blown from the evaporator 13, the
first and second coolant temperature sensors 65, 66 for detecting
the coolant temperature TW of the engine EG. The air temperature TE
blown from the evaporator 13 corresponds to a refrigerant
evaporation temperature in the evaporator 13.
[0105] An operation panel 70 is located near the instrument panel
at the front portion of the vehicle compartment. The operation
panel 70 is connected to the input side of the air conditioning
controller 60, such that operation signals of various
air-conditioning operation switches provided in the operation panel
70 are input to the air conditioning controller 60. The
air-conditioning operation switches provided in the operation panel
70 include, for example, an operation switch (not shown) of the air
conditioner 1, an air-conditioning switch 70a for selectively
turning on or off of the compressor thereby turning on or off of
the air conditioning operation of the air conditioner 1, an
automatic switch 70b for setting or releasing an automatic control
of the air conditioner 1, an operation mode selecting switch (not
shown) for selecting an operation mode, a suction mode selecting
switch (not shown) for selectively switching an air suction mode,
an air outlet mode selecting switch (not shown) for selectively
switching an air outlet mode, an air amount setting switch (not
shown) for setting an air blowing amount of the blower 12, a
temperature setting switch 70c for setting a temperature of the
vehicle compartment, an economic switch 70d for outputting an
economy priority mode in which the refrigerant cycle is operated
with a priority of the power saving.
[0106] The air conditioning controller 60 is electrically connected
to an engine controller 80 which controls operation of the engine
EG. The air conditioning controller 60 and the engine controller 80
are configured to be capable of electrically communicating with
each other. Based on detection signals or/and operation signals
inputted from one of the engine controller 80 and the air
conditioning controller 60, operation of various equipments
connected to the other one of the engine controller 80 and the air
conditioning controller 60 can be controlled. For example, when the
air conditioning controller 60 outputs an operation request signal
to the engine controller 80, the engine controller 80 causes the
engine EG to be operated.
[0107] Next, the operation of the present embodiment with the above
configuration will be described with reference to FIG. 3. FIG. 3 is
a flowchart showing a basic control process performed by the air
conditioning controller 60 in the first embodiment. The respective
steps in FIG. 3 correspond to respective function portions provided
in the air conditioning controller 60.
[0108] First, at step S1, initialization of a flag, a timer, a
control variable, and an initial position setting of a stepping
motor in respective electrical motors, and the like are
performed.
[0109] At step S2, operation signals of the operation panel 70 and
signals regarding the circumstances of the vehicle used for the air
conditioning control, that is, detection signals from the above
group of sensors 61 to 66 are read, and then the operation proceeds
to step S3. Specifically, the operation signals include a vehicle
interior setting temperature Tset set by the temperature setting
switch 70c, a selection signal of the air outlet mode, a selection
signal of the air suction mode, a setting signal of the amount of
air blown by the blower 12, and the like.
[0110] At step S3, a target outlet air temperature TAO of blown air
into the vehicle compartment is calculated. The target outlet air
temperature TAO of blown air into the vehicle compartment is
calculated based on the vehicle interior setting temperature Tset
and the vehicle environment condition such as the inside air
temperature, by using the following formula F1.
TAO=Kset.times.Tset-Kr.times.Tr-Kam.times.Tam-Ks.times.Ts+C
(F1)
[0111] where Tset is a vehicle interior setting temperature set by
the temperature setting switch 70c, Tr is an inside air temperature
detected by the inside air sensor 61, Tam is an outside air
temperature detected by the outside air sensor 62, and Ts is an
amount of solar radiation detected by the solar radiation sensor
63. The Kset, Kr, Kam, and Ks are control gains, and C is a
constant for correction.
[0112] Next, at step S4, control target values of the various
equipments connected to the output side of the air conditioning
controller 60 are determined. For example, the air blowing amount
(blower level) of the blower 12, the air suction mode, the air
outlet mode, the open degree of the air mix door 19, the engine
operation request signal and ON/OFF operation of the Peltier
element 53 and the like are determined. The air blowing amount and
the air outlet mode and the like are determined based on the target
outlet air temperature TAO calculated at S3. Furthermore, the air
conditioning controller 60 determines whether the engine operation
request signal is output or not based on the engine coolant
temperature TW. For example, when the engine coolant temperature TW
detected by the first coolant temperature sensor 65 is lower than a
predetermined temperature TW1, the air conditioning controller 60
outputs the engine operation request signal to the engine EG. Next,
the ON/OFF operation determination of the Peltier element 53 will
be described.
[0113] Then, at step S5, control signals are output from the air
conditioning controller 60 to various air-conditioning control
equipments or the engine controller 80, such that the control
target values determined at step S4 of FIG. 3 can be obtained.
[0114] Thus, the blower 12 is operated to have a predetermined air
blowing amount, the air outlet mode doors are positioned to set a
desired air outlet mode, and the engine EG is operated in
accordance with the engine operation request signal output from the
air conditioning controller 60, for example.
[0115] Next, at step S6, it is determined whether a control period
elapses. When it is determined that the control period .tau.
elapses at step S6, the control program returns to step S2.
[0116] Next, the control process of step S4 for determining the
ON/OFF operation of the Peltier element 53 will be described in
detail. FIG. 4 is a flowchart for determining ON/OFF operation of
the Peltier element 53, according to the present embodiment.
[0117] At step S11, a temperature TWD of air blown from the second
heater core 15 is calculated. The air temperature TWD is a heated
temperature of air heated by the engine coolant at least at the
second heater core 15. The air temperature TWD can be calculated by
the coolant temperature detected by the second coolant temperature
sensor 66, the air temperature TE after passing through the
evaporator 13 and the heat exchange capacity of the heater core 15
and the like. Generally, the air temperature TWD blown out of the
second heater core 15 is approximately equal to the coolant
temperature detected by the second coolant temperature sensor
66.
[0118] Next, at step S12, the air temperature TWD blown from the
second heater core 15 is compared with the target outlet air
temperature TAO. When the air temperature TWD is lower than the
target outlet air temperature TAO at step S12, the Peltier element
53 is turned on at step S13. When the air temperature TWD is not
lower than the target outlet air temperature TAO at step S12, the
Peltier element 53 is turned off at step S14.
[0119] For example, when a long time elapses after the engine EG
stops, the coolant temperature may become lower, and thereby the
air temperature TWD may become lower than the target outlet air
temperature TAO. In this case, in the present embodiment,
electrical power is supplied to the Peltier element 53, such that
heat is absorbed from the coolant after passing through the second
heater core 15, and heat is radiated to the coolant flowing toward
the second heater core 15. Thus, the temperature of the coolant
flowing into the second heater core 15 is increased to a
temperature required for the heating of the vehicle compartment. In
this case, it is prefer to set the air mix door 19 at the maximum
heating position, by the air conditioning controller 60.
[0120] When the engine EG is operated or an elapsed time after the
stop of the engine EG is shorter, the coolant temperature is
sufficiently high. In this case, if the air temperature TWD is
equal to or higher than the target outlet air temperature TAO, it
is unnecessary to heat the engine coolant by using the operation of
the Peltier element 53. In this case, the Peltier element 53 is not
turned on by the air conditioning controller 60, and the position
(open degree) of the air mix degree 19 is controlled by the air
conditioning controller 60, thereby adjusting the temperature of
conditioned air to be blown into the vehicle compartment.
[0121] The operation effects of the first embodiment will be
described.
[0122] (1) According to the present embodiment, when the air
temperature TWD from the second heater core 15 is lower than the
target outlet air temperature TAO, the temperature of the coolant
flowing into the second heater core 15 is increased by the
operation of the Peltier element 53, instead of the operation of
the engine EG. Thus, the operation frequency of the engine EG can
be reduced, thereby improving the fuel consumption efficiency of
the engine EG, as compared with an air conditioner without having
the Peltier element 53.
[0123] Because the temperature of the engine coolant is increased
by the operation of the Peltier element 53, it is possible to delay
the temperature decrease of the engine coolant immediately after
the stop of the engine EG, and thereby a time, for which the engine
coolant temperature TW detected by the first coolant temperature
sensor 65 becomes equal to or higher than the engine-operation
required temperature, can be made longer. Accordingly, in the
present embodiment, as compared with a case where the Peltier
element 53 is not provided, the operation frequency of the engine
EG can be effectively reduced.
[0124] (2) Generally, the temperature of the engine coolant flowing
into the second heater core 15 is preferably equal to or higher
than a necessary temperature required for the heating, e.g.,
60.degree. C. On the other hand, the temperature of the coolant
flowing into the interior of the engine EG is preferably equal to
or higher than a lower limit temperature for effectively heating
the respective parts of the engine EG. Here, the lower limit
temperature is 40.degree. C., for example.
[0125] Thus, in a conventional vehicle air conditioner without
having the Peltier element 53, the engine-operation required
temperature is set at a temperature around 60.degree. C. in order
to keep the coolant temperature equal to or higher than 60.degree.
C.
[0126] In contrast, according to the present embodiment, when the
temperature of the engine coolant becomes lower than 60.degree. C.
while the engine EG stops, the Peltier element 53 is operated so
that the temperature of the engine coolant is increased. Thus, it
is possible to set the engine-operation required temperature to be
lower than 60.degree. C. For example, the engine-operation required
temperature is set at a temperature about 40.degree. C.
[0127] In the present embodiment, the engine-operation request
temperature can be set at a temperature at which the necessary
heating of the vehicle compartment cannot be maintained even when
the Peltier element 53 is operated, or the engine-operation request
temperature can be set at a temperature at which the engine EG
cannot be effectively operated.
[0128] (3) In the present embodiment, the Peltier element 53
absorbs heat from the coolant of the engine EG, which is a subject
to be heat-absorbed.
[0129] The subject to be heat-absorbed in the Peltier element 53
may be an outside air, instead of the coolant of the engine EG.
However, when the Peltier element 53 absorbs heat from the outside
air, a heat pump capacity required in the Peltier element 53
becomes larger as the outside air temperature becomes lower, and
thereby the consumed electrical power of the Peltier element 53
becomes larger.
[0130] In contrast, according to the present embodiment, the
Peltier element 53 absorbs heat from the engine coolant that has a
temperature generally higher than the temperature of the outside
air in the winter. Thus, it is possible to increase the heat
radiation amount radiated from the Peltier element 53 to the
coolant. As a result, the consumed power of the Peltier element 53,
consumed for increasing the temperature of the coolant to a desired
temperature, can be reduced.
[0131] According to the present embodiment, when the coolant
temperature TW detected by the first coolant temperature sensor 65
is lower than the required temperature (40.degree. C.) of the
engine operation, the engine operation request signal is output to
the engine EG: Thus, the coolant temperature can be kept at a
temperature equal to or higher than the required temperature, and
thereby the coolant temperature always becomes higher than the
outside air temperature.
[0132] (4) when the Peltier element 53 is not provided, the coolant
flowing out of the second heater core 15 flows simply into the
engine EG. In this case, the heat quantity without heat-exchanged
with air in the second heater core 15 is radiated from the surface
of the engine EG.
[0133] In contrast, according to the present embodiment, because
the heat is pumped from the coolant flowing out of the second
heater core 15 by the Peltier element 53, the heat quantity without
being heat exchanged with air in the second heater core 15 can be
further used for the heating of the vehicle compartment. Thus, the
heat quantity of the engine coolant can be effectively used.
Second Embodiment
[0134] A second embodiment of the invention will be described with
reference to FIG. 5. FIG. 5 is a schematic diagram showing an air
conditioner 1 for a vehicle according to the second embodiment of
the invention.
[0135] In a coolant circuit 30 of the second embodiment, a second
coolant passage 34 for the second heater core 15 is made different
from that of the first embodiment. As shown in FIG. 5, a first
bypass passage 35 is provided, such that a part of coolant flowing
into the second coolant passage 34 from the branch point 31a is
directly introduced into the heat-absorption side heat exchanger 51
through the first bypass passage 35, without passing through the
heat-radiation side heat exchanger 52. Furthermore, a first flow
adjustment valve 36 is disposed to adjust a flow amount of the
coolant flowing through the first bypass passage 35.
[0136] Specially, one end of the first bypass passage 35 is
connected to an upstream side of the heat-radiation side heat
exchanger 52 in the coolant flow, and the other end of the first
bypass passage 35 is connected to a position of the second coolant
passage 34 between a coolant outlet of the second heater core 15
and a coolant inlet of the heat-absorption side heat exchanger 51.
Therefore, the coolant flowing through the first bypass passage 35
bypasses the heat-radiation side heat exchanger 52 and the second
heater core 15, and flows into the heat-absorption side heat
exchanger 51, without radiating heat at the heat-radiation side
heat exchanger 52 and without performing heat exchange with air at
the second heater core 15.
[0137] In the example of FIG. 5, the first flow adjustment valve 36
is located at a branch portion of the first bypass passage 35
branched from the coolant passage flowing through the heat
radiation-side heat exchanger 52. Therefore, the flow adjustment
valve 36 can easily adjust a flow amount of the coolant flowing
into the heat-radiation side heat exchanger 52 and a flow amount of
the coolant flowing through the first bypass passage 35. However,
the first flow adjustment valve 36 may be disposed at any position
in the first bypass passage 35, without being limited to the branch
portion of the first bypass passage 35. For example, the first flow
adjustment valve 36 may be located at a joint portion at which the
downstream end of the first bypass passage 35 is joined to a
coolant passage from the second heater core 15.
[0138] In the present embodiment, the air conditioning controller
60 controls the first flow adjustment valve 36, such that a part of
the coolant flows into the first bypass passage 35 when the Peltier
element 53 is turned on, and the flow amount of the coolant flowing
through the first bypass passage 35 becomes zero when the Peltier
element 53 is turned off.
[0139] According to the present embodiment, when the Peltier
element 53 is turned on so that electrical current is applied to
the Peltier element 53, a part of the coolant before flowing to the
heat-radiation side heat exchanger 52 is introduced into the inlet
side of the heat-absorption side heat exchanger 51. Therefore, the
temperature of the coolant flowing into the heat-radiation side
heat exchanger 52 can be approached to the temperature of the
coolant flowing into the heat-absorption side heat exchanger 51.
Generally, the heat radiation amount of the Peltier element 53
becomes larger, as a temperature difference between the heat
absorbing surface and the heat radiating surface of the Peltier
element 53 is smaller. Thus, according to the present embodiment,
because the first bypass passage 35 is provided, the heat radiation
amount radiated to the coolant in the heat-radiation side heat
exchanger 52 can be made larger, and thereby the temperature
increase of the coolant flowing into the second heater core 15 can
be made larger.
[0140] According to the present embodiment, when the Peltier
element 53 is turned on so that the electrical current is applied
to the Peltier element 53, the air conditioning controller 60
controls the first flow adjustment valve 36, so as to adjust the
flow amount of the coolant flowing through the first bypass passage
35 in accordance with the heating capacity required in the second
heater core 15.
[0141] For example, when an air amount blown from an air outlet
into the vehicle compartment is small, the heating capacity
required in the second heater core 15 is generally small. In this
case, the flow amount of the coolant flowing through the first
bypass passage 35 can be made larger than the flow amount of the
coolant flowing through the heat-radiation side heat exchanger 52.
Thus, the flow amount of the coolant flowing into the second heater
core 15 can be reduced, and thereby the temperature increase in the
coolant due to the heat radiation of the heat-radiation side heat
exchanger 52 can be increased.
[0142] Furthermore, when the air amount blown from the air outlet
into the vehicle compartment is large, the heating capacity
required in the second heater core 15 is generally large. In this
case, the flow amount of the coolant flowing through the first
bypass passage 35 can be made smaller than the flow amount of the
coolant flowing through the heat-radiation side heat exchanger 52.
In this case, the flow amount of the coolant flowing through the
heat-radiation side heat exchanger 52 can be made larger, and
thereby the heating capacity of the second heater core 15 can be
increased.
[0143] In the above-described second embodiment, the first flow
adjustment valve 36 is used to adjust the flow amount flowing
through the first bypass passage 35. However, a flow switching
valve may be used instead of the first flow adjustment valve 36, to
switch the flow amount flowing through the first bypass passage 35
between zero and a predetermined amount larger than zero. In the
above-described second embodiment, the other parts of the air
conditioner 1 may be similar to those of the above-described first
embodiment.
Third Embodiment
[0144] A third embodiment of the invention will be described with
reference to FIG. 6. FIG. 6 is a schematic diagram showing an air
conditioner 1 for a vehicle according to the third embodiment of
the invention.
[0145] In the vehicle air conditioner 1 of the present embodiment,
a foot passage 27 is provided through which warm air flowing out of
the second heater core 15 is introduced only to the foot opening
portion 26. A partition wall 11a is disposed in the casing 11 to
partition a space of the casing 11 at a downstream air side of the
second heater core 15 into the foot passage 27 on a side of the
foot opening portion 26 and an air passage on a side of the opening
portions 24, 25. The foot passage 27 is formed by the partition
wall 11a in the casing 11.
[0146] A communication opening portion 28 is provided in the
partition wall 11a at a position immediately downstream of the
second heater core 15, and an opening/closing door 28a is disposed
at the position immediately after the second heater core 15 to open
and close the communication opening portion 28. When the
opening/closing door 28a opens the communication opening portion
28, the warm air flowing out of the second heater core 15 can be
introduced to any the defroster opening portion 24, the face
opening portion 25 and the foot opening portion 26. In contrast,
when the opening/closing door 28a closes the communication opening
portion 28, the warm air flowing out of the second heater core 15
is only introduced to the foot opening portion 26.
[0147] Furthermore, the size of the first heater core 14 is made
larger than the size of the second heater core 15. Specifically,
the sectional area of the first heater core 14 is made larger than
the sectional area of the second heater core 15, so that a part of
warm air flowing out of the first heater core 14 flows to the
defroster opening portion 24 and the face opening portion 25
without passing through the second heater core 15, when the
opening/closing door 28a closes the communication opening portion
28.
[0148] In the present embodiment, when the Peltier element 53 is
turned on, the air conditioning controller 60 causes the
opening/closing door 28a to close the communication opening portion
28. Thus, in a foot mode in which the conditioned air is blown,
from the foot air outlet and side face air outlets, the
communication opening portion 28 is closed by the opening/closing
door 28a, so that air heated by the first and second heater cores
14, 15 is blown to the lower side of a passenger from the foot air
outlet, and air heated by the first heater core 14 is mixed with
cool air flowing through the second air passage 17 and is blown
into the vehicle compartment from the side face air outlets. Thus,
air conditioning with "cool-head and warm-foot" can be performed,
thereby improving comfortable feeling given to a passenger in the
vehicle compartment. In the above-described third embodiment, the
other parts of the air conditioner 1 may be similar to those of the
above-described first embodiment.
Fourth Embodiment
[0149] A fourth embodiment of the invention will be described with
reference to FIG. 7. FIG. 7 is a schematic diagram showing an air
conditioner 1 for a vehicle according to the fourth embodiment of
the invention.
[0150] In the above-described first to third embodiments, the
coolant circuit 30 is provided such that the coolant flows to the
first and second heater cores 14, 15 in parallel with respect to
the flow of the coolant. However, in the fourth embodiment, the
coolant circuit 30 is provided such that the coolant flows to the
first and second heater cores 14, 15 in series with respect to the
flow of the coolant. That is, in the fourth embodiment, the first
and second heater cores 14, 15 are arranged in series with respect
to the flow of the coolant.
[0151] Specifically, the coolant circuit 30 is provided with a
single coolant passage 31 for both the first and second heater
cores 14, 15, such that the coolant flowing out of the coolant
outlet of the engine EG flows through the first heater core 14 and
the second heater core 15 in this order, and returns to the coolant
inlet of the engine EG. Thus, the first heater core 14 is arranged
upstream of the coolant flow, and the second heater core 15 is
arranged downstream of the coolant flow, in the coolant circuit
30.
[0152] The heat-absorption side heat exchanger 51 is located
downstream of the second heater core 15 in the coolant flow, and
the heat-radiation side heat exchanger 52 is located downstream of
the first heater core 14 in the coolant flow and upstream of the
second heater core 15 in the coolant flow.
[0153] In the present embodiment, heat can be absorbed by the
Peltier element 53 via the heat-absorption side heat exchanger 51
from the coolant after performing heat exchange with air in the
second heater core 15, and heat can be radiated by the Peltier
element 53 via the heat-radiation side heat exchanger 52 to the
coolant flowing to the second heater core 15. Therefore, the
Peltier effect can be obtained similarly to the above described
first embodiment.
[0154] In the present embodiment, because the coolant after
performing heat exchange with air in the first heater core 14 flows
into the heat-radiation side heat exchanger 52, the heating
capacity of the second heater core 15 is generally lower than the
heating capacity of the first heater core 14. However, heat can be
radiated by the Peltier element 53 via the heat-radiation side heat
exchanger 52, the heating capacity of the second heater core 15 can
be assisted by the Peltier element 53. In the above-described
fourth embodiment, the other parts of the air conditioner 1 may be
similar to those of the above-described first embodiment.
Fifth Embodiment
[0155] A fifth embodiment of the invention will be described with
reference to FIG. 8. FIG. 8 is a schematic diagram showing an air
conditioner 1 for a vehicle according to the fifth embodiment of
the invention.
[0156] In the air conditioner 1 according to any one of the
above-described first to fourth embodiments, two heater cores such
as the first and second heater cores 14, are disposed. In the air
conditioner 1 for a vehicle, a single heater core 14 is disposed to
heat air to be blown into the vehicle compartment.
[0157] In the vehicle air conditioner 1, a coolant circuit 30 of
the engine EG is provided such that the coolant is circulated
between the heater core 14 and the engine EG. In the present
embodiment, the coolant circuit 30 is provided with a coolant
passage 31 for the heater core 14 and a coolant passage 32 for the
radiator 41.
[0158] In the present embodiment, the heat-absorption side heat
exchanger 51 is disposed in the coolant passage 31 at a downstream
side of the heater core 14 in the coolant flow, and the
heat-radiation side heat exchanger 52 is disposed in the coolant
passage 31 at an upstream side of the heater core 14 in the coolant
flow.
[0159] In the present embodiment, heat can be absorbed by the
Peltier element 53 via the heat-absorption side heat exchanger 51
from the coolant after performing heat exchange with air in the
heater core 14, and heat can be radiated by the Peltier element 53
via the heat-radiation side heat exchanger 52 to the coolant
flowing to the second heater core 14. Therefore, the Peltier effect
can be obtained similarly to the above described first embodiment.
In the above-described fifth embodiment, the other parts of the air
conditioner 1 may be similar to those of the above-described first
embodiment.
Sixth Embodiment
[0160] A sixth embodiment of the invention will be described with
reference to FIG. 9. FIG. 9 is a schematic diagram showing an air
conditioner 1 for a vehicle according to the sixth embodiment of
the invention. In the sixth embodiment, the features of the second
embodiment described above are combined with the air conditioner 1
of the above-described sixth embodiment.
[0161] In the coolant circuit 30 of the sixth embodiment, as shown
in FIG. 9, a first bypass passage 35 is provided, such that a part
of coolant flowing through the coolant passage 31 is introduced
into the heat-absorption side heat exchanger 51 through the first
bypass passage 35, without passing through the heat-radiation side
heat exchanger 52. Furthermore, a first flow adjustment valve 36 is
disposed to adjust a flow amount of the coolant flowing through the
first bypass passage 35. Specially, one end of the first bypass
passage 35 is connected to an upstream side of the heat-radiation
side heat exchanger 52 in the coolant flow, and the other end of
the first bypass passage 35 is connected to a position of the
coolant passage 31 between a coolant outlet of the heater core 14
and a coolant inlet of the heat-absorption side heat exchanger 51.
Therefore, the coolant flowing through the first bypass passage 35
bypasses the heat-radiation side heat exchanger 52 and the heater
core 14, and flows into the heat-absorption side heat exchanger 51,
without radiating heat at the heat-radiation side heat exchanger 52
and without performing heat exchange with air at the heater core
14. In the example of FIG. 9, the first flow adjustment valve 36 is
located at a branch portion of the first bypass passage 35 branched
from the coolant passage 31. Therefore, the flow adjustment valve
36 can easily adjust a flow amount of the coolant flowing into the
heat-radiation side heat exchanger 52 and a flow amount of the
coolant flowing through the first bypass passage 35.
[0162] However, the first flow adjustment valve 36 may be disposed
at any position in the first bypass passage 35, without being
limited to the branch portion of the first bypass passage 35. The
flow adjustment valve 36 is controlled by the air conditioning
controller 60, similarly to the second embodiment. Thus, in the
present embodiment, the effects described in the second embodiment
can be obtained. In the above-described sixth embodiment, the other
parts of the air conditioner 1 may be similar to those of the
above-described fifth embodiment shown in FIG. 8.
Seventh Embodiment
[0163] A seventh embodiment of the invention will be described with
reference to FIG. 10. FIG. 10 is a schematic diagram showing an air
conditioner 1 for a vehicle according to the seventh embodiment of
the invention.
[0164] In the seventh embodiment, the single heater core 14 is
disposed in the casing 11 to heat air to be blown into the vehicle
compartment, as in the above-described fifth embodiment of FIG. 8.
In the seventh embodiment, a heat exchanger 37 is disposed, with
respect to the coolant circuit 30 of the above-described fifth
embodiment shown in FIG. 8. In the seventh embodiment, the heat
exchanger 37 is disposed to perform heat exchange between the
coolant before flowing into the heat-radiation side heat exchanger
52 and the coolant before flowing into the heat-absorption side
heat exchanger 51.
[0165] The heat exchanger 37 has therein a first passage through
which the coolant upstream of the heat-radiation side heat
exchanger 52 flows, and a second passage through which the coolant
downstream of the heater core 14 flows, so as to perform heat
exchange between the coolant passing through the first passage and
the coolant passing through the second passage in the heat
exchanger 37. Therefore, the coolant flowing out of the heater core
14 is heated by performing heat exchange with the coolant flowing
out of the engine EG, and then flows through the heat-absorption
side heat exchanger 51.
[0166] Thus, the temperature of the coolant flowing into the
heat-radiation side heat exchanger 52 can be approached to the
temperature of the coolant flowing into the heat-absorption side
heat exchanger 51. Generally, the heat radiation amount of the
Peltier element 53 becomes larger, as a temperature difference
between the heat absorbing surface and the heat radiating surface
of the Peltier element 53 is smaller. Thus, according to the
present embodiment, because the heat exchanger 37 is provided, the
heat radiation amount radiated to the coolant in the heat-radiation
side heat exchanger 52 can be made larger, and thereby the
temperature increase of the coolant flowing into the heater core 14
can be made larger. In the above-described seventh embodiment, the
other parts of the air conditioner 1 may be similar to those of the
above-described fifth embodiment shown in FIG. 8.
Eighth Embodiment
[0167] An eighth embodiment of the present invention will be
described with reference to FIG. 11. FIG. 11 is a schematic diagram
showing an air conditioner 1 for a vehicle according to the eighth
embodiment of the invention.
[0168] In a coolant circuit 30 of the eighth embodiment, as shown
in FIG. 11, a second bypass passage 38 is provided, such that a
part of coolant flowing through the coolant passage 31 is
introduced into the coolant inlet of the engine EG, without passing
through the heat-radiation side heat exchanger 52. Furthermore, a
second flow adjustment valve 39 is disposed to adjust a flow amount
of the coolant flowing through the second bypass passage 38.
[0169] Specially, one end of the second bypass passage 38 is
connected to a coolant upstream side of the heat-radiation side
heat exchanger 52 at a downstream side of the coolant outlet of the
engine EG, and the other end of the second bypass passage 38 is
connected to a coolant downstream side of the heat-absorption side
heat exchanger 51 at an upstream side of the coolant inlet of the
engine EG. Therefore, coolant flowing through the second bypass
passage 38 bypasses the heat-radiation side heat exchanger 52, the
heater core 14 and the heat-absorption side heat exchanger 51, and
directly returns to the engine EG.
[0170] In the example of FIG. 11, the second flow adjustment valve
39 is located at a branch portion of the second bypass passage 38
branched from the coolant passage flowing through the heat
radiation-side heat exchanger 52. Therefore, the flow adjustment
valve 39 can easily adjust a flow amount of the coolant flowing
into the heat-radiation side heat exchanger 52 and a flow amount of
the coolant flowing through the second bypass passage 38. However,
the second flow adjustment valve 39 may be disposed at any position
in the second bypass passage 38, without being limited to the
branch portion of the second bypass passage 38.
[0171] In the present embodiment, the air conditioning controller
60 controls the second flow adjustment valve 39, such that a part
of the coolant flows into the second bypass passage 38 when the
Peltier element 53 is turned on, and the flow amount of the coolant
flowing through the second bypass passage 38 becomes zero when the
Peltier element 53 is turned off.
[0172] Because heat is absorbed from the coolant by the Peltier
element 53, the temperature of the coolant flowing out of the
heat-absorption side heat exchanger 51 becomes lower, and thereby a
temperature difference between the coolant flowing into the coolant
inlet of the engine EG and the coolant outlet of the engine EG may
become larger. If the temperature difference between the coolant
inlet and the coolant outlet of the engine EG is large, a heat
stress may be caused in the engine EG, and the engine EG may be
damaged.
[0173] According to the present embodiment, when the Peltier
element 53 is turned on, a part of the coolant upstream of the
heat-radiation side heat exchanger 52 is introduced to the coolant
inlet side of the engine EG via the second bypass passage 38. Thus,
the temperature difference between the coolant flowing into the
coolant inlet of the engine EG and the coolant flowing out of the
coolant outlet of the engine EG can be reduced, thereby preventing
a heat stress of the engine EG.
[0174] When the second bypass passage 38 is provided, the flow
amount of the coolant flowing through the second coolant passage 38
may be made larger than the flow amount of the coolant flowing
toward the heat-radiation side heat exchanger 52. In this case, the
temperature difference between the coolant flowing into the coolant
inlet of the engine EG and the coolant flowing out of the coolant
outlet of the engine EG can be reduced.
[0175] In the above-described second embodiment, the second flow
adjustment valve 39 is used to adjust the flow amount of the
coolant flowing through the second bypass passage 38. However, a
flow switching valve may be used instead of the second flow
adjustment valve 38, to switch the flow amount flowing through the
second bypass passage 38 between zero and a predetermined amount
larger than zero. In the above-described eighth embodiment, the
other parts of the air conditioner 1 may be similar to those of the
above-described fifth embodiment shown in FIG. 8.
Ninth Embodiment
[0176] A ninth embodiment of the present invention will be
described with reference to FIG. 12. FIG. 12 is a schematic diagram
showing an air conditioner 1 for a vehicle according to the eighth
embodiment of the invention.
[0177] In a coolant circuit 30 of the ninth embodiment, as shown in
FIG. 12, a third bypass passage 54 and a third flow adjustment
valve 55 are provided, as compared with the coolant circuit 30 of
the above-described fifth embodiment shown in FIG. 8. The third
bypass passage 55 is provided such that a part of coolant flowing
through the coolant passage 31 is introduced into the
heat-absorption side heat exchanger 51, without passing through the
heat-radiation side heat exchanger 52 and the heater core 14.
Furthermore, the third flow adjustment valve 55 is disposed to
adjust a flow amount of the coolant flowing through the third
bypass passage 54.
[0178] The coolant passage 31 for the heater core 14 is provided
such that the coolant flowing out of the coolant outlet of the
engine EG flows toward the heater core 14, and the coolant flowing
out of the heater core 14 flows toward the coolant inlet of the
engine EG. In the example of FIG. 12, the third flow adjustment
valve 55 is located at a branch portion of the third bypass passage
54 branched from the coolant passage 31 flowing through the heat
radiation-side heat exchanger 52.
[0179] Furthermore, the heat-absorption side heat exchanger 51 is
disposed in the third bypass passage 54 so that the coolant flowing
into the third bypass passage 54 flows through the heat-absorption
side heat exchanger 51. Therefore, the heat-absorption side heat
exchanger 51 absorbs heat from the coolant flowing out of the
coolant outlet of the engine EG, and thereby the coolant after
performing heat exchange with air in the heater core 14 does not
flow into the heat-absorption side heat exchanger 51.
[0180] The heat-radiation side heat exchanger 52 is located
downstream of the third flow adjustment valve 55 in the coolant
passage 31, and upstream of the heater core 14 in the coolant
flow.
[0181] In the present embodiment, the air conditioning controller
60 controls the third flow adjustment valve 55, such that the
coolant flows into both the heat-absorption side heat exchanger 51
and the heat-radiation side heat exchanger 52 when the Peltier
element 53 is turned on. Furthermore, the third flow adjustment
valve 55 is controlled by the air conditioning controller 60 to
close the third bypass passage 54 so that the coolant flows only
toward the heater core 14 when the Peltier element 53 is turned
off.
[0182] According to the present embodiment, when the Peltier
element 53 is turned on, the coolant flowing out of the coolant
outlet of the engine EG flows to both the heat-absorption side heat
exchanger 51 and the heat-radiation side heat exchanger 52, and
thereby the heat absorbing surface and the heat radiating surface
of the Peltier element 53 have the same temperature. Thus,
according to the present embodiment, the heat radiation amount of
the Peltier element 53 can be effectively increased. In the
above-described ninth embodiment, the other parts of the air
conditioner 1 may be similar to those of the above-described fifth
embodiment shown in FIG. 8.
Tenth Embodiment
[0183] A tenth embodiment of the present invention will be
described with reference to FIG. 13. FIG. 13 is a schematic diagram
showing an air conditioner 1 for a vehicle according to the tenth
embodiment of the invention.
[0184] In the tenth embodiment, as shown in FIG. 13, a water
circuit 90 is separately provided from a coolant circuit 30 for the
engine EG.
[0185] The coolant circuit 30 is a closed circuit through which
coolant of the engine EG is circulated between the engine EG, the
heat-absorption side heat exchanger 51 and the radiator 41. The
coolant flowing out of the engine EG flows through the
heat-radiation side heat exchanger 51 via a coolant passage 31, and
flows through the radiator 41 via a coolant passage 32.
[0186] The water circuit 90 is a circuit independently provided
from the coolant circuit 30, and is provided to heat the air
passing through the heater core 14 by using a hot water (fluid) as
a heat source. In the present embodiment, water is circulated as an
example of the fluid circulating in the water circuit 90. A water
pump 92 is located in a water, passage 91 of the water circuit 90
such that hot water heated by the Peltier element 53 via the
heat-radiation side heat exchanger 52 circulates in the water
passage 91 of the water circuit 90.
[0187] In the present embodiment, the heat-absorption side heat
exchanger 51 is disposed in the coolant circuit 30 to absorb heat
from the coolant of the engine EG. In contrast, the heat-radiation
side heat exchanger 52 is located in the water circuit 90 so that
heat is radiated to the water in the water passage 91 of the water
circuit 90. Thus, when the Peltier element 53 is turned on, the
Peltier element 53 absorbs heat from the coolant of the engine EG
via the heat-absorption side heat exchanger 51, and radiates heat
to the water in the water circuit 90 via the heat-radiation side
heat exchanger 52. Therefore, water flowing through the
heat-radiation side heat exchanger 52 is heated, and the heated
water flows into the heater core 14. Thus, in the present
embodiment, air is heated in the heater core 14 by indirectly using
the coolant of the engine EG as a heat source.
[0188] A first temperature sensor 65 is disposed in the coolant
passage 31 of the coolant circuit 30 to detect the temperature of
the coolant flowing out of the coolant outlet of the engine EG, and
a second temperature sensor 66 is disposed in the coolant passage
91 of the water circuit 90 to detect the temperature of the water
flowing into the heater core 14.
[0189] When the coolant temperature detected by the first
temperature sensor 65 is lower than a required coolant temperature
TW1, the air conditioning controller 60 outputs an engine operation
request signal to the engine EG. For example, in the present
embodiment, the required coolant temperature TW1 is set at a lower
limit temperature (e.g., 40.degree. C.) in which the engine EG can
be effectively operated. Thus, in the present embodiment, the
temperature of the coolant can be maintained to be equal to or
higher than the lower limit temperature (e.g., 40.degree. C.) in
which the engine EG can be effectively operated.
[0190] On the other hand, in the water circuit 90, the air
conditioning controller 60 controls the turning on/off operation of
the Peltier element 53 such that the water temperature detected by
the second temperature sensor 66 becomes equal to or higher than a
temperature (e.g., 60.degree. C.) that is higher than the lower
limit temperature (e.g., 40.degree. C.) of the engine EG.
[0191] According to the present embodiment, the heat is pumped from
the coolant of the engine. EG to the water flowing into the heater
core 14, so that the temperature of water flowing into the heater
core 14 becomes higher than a necessary heating temperature. Thus,
it is unnecessary to set the temperature of the coolant of the
engine EG to be kept at a temperature equal to or higher than the
necessary heating temperature. Thus, in the present embodiment,
because the engine-operation required temperature can be set lower,
the operation frequency of the engine EG can be reduced, and
thereby the fuel consumption efficiency of the engine EG can be
improved.
[0192] In the present embodiment, the Peltier element 53 absorbs
heat from the coolant of the engine EG, which is a subject to be
heat-absorbed. Therefore, the above effect (3) described in the
first embodiment can be obtained.
[0193] Because the water circuit 90 is formed separately from the
engine coolant circuit 30, it can prevent heat of the water circuit
90, without being heat-exchanged with air in the heater core 14,
from being radiated at the engine.
[0194] Thus, in the present embodiment, hot water is circuited in
the closed water circuit 90, and thereby all the heat pumped at the
Peltier element 53 can be used for the heating of air in the heater
core 14.
[0195] In the present embodiment, the single heater core 14 is
provided in the casing 11 to heat air. However, in the present
embodiment, two heater cores may be located similarly to the first
and second heater cores of the above-described first embodiment.
For example, a first heater core is located in the casing 11 at an
upstream air side, and a second heater core is located in the
casing 11 at a downstream air side of the first core. In this case,
the coolant of the engine EG may be supplied to the first heater
core, and water of the water circuit 90 shown in FIG. 13 may flow
to the second heater core as in the heater core 14 of FIG. 13.
[0196] In this case, in the coolant circuit 30, a coolant passage
for supplying the coolant to the first heater core and a coolant
passage for the heat-absorption side heat exchanger 51 may be
arranged in parallel with respect the flow of the coolant. Thus, it
is possible to increase the temperature of the coolant to be
supplied to both the first heater core and the heat-absorption side
heat exchanger 51. In the above-described tenth embodiment, the
other parts of the air conditioner 1 may be similar to those of the
above-described first embodiment.
Eleventh Embodiment
[0197] An eleventh embodiment of the invention will be described
with reference to FIG. 14. FIG. 14 is a schematic diagram showing
an air conditioner 1 for a vehicle according to the eleventh
embodiment of the invention. In the eleventh embodiment, a heat
pump cycle 100 is used as a heat pump device.
[0198] Specifically, in a vehicle air conditioner 1 of the present
embodiment, a heat pump cycle 100 is used instead of the Peltier
element 53, as compared with the vehicle air conditioner 1 shown in
FIG. 8.
[0199] The heat pump cycle 100 includes a compressor 101, a
radiator 102, an expansion valve 103, a heat absorbing, unit 104, a
gas-liquid separator 105 and a refrigerant pipe 106. The compressor
101 is adapted to compress refrigerant and to discharge the
compressed refrigerant. The radiator 102 is disposed to cool and
radiate the high-pressure refrigerant discharged from the
compressor 101.
[0200] The expansion valve 103 is disposed to decompress and expand
the high-pressure refrigerant flowing out of the radiator 102. The
heat absorbing unit 104 is disposed so that the low pressure
refrigerant decompressed by the expansion valve 103 absorbs heat in
the heat absorbing unit 104. Furthermore, the gas-liquid separator
105 is disposed to separate the low-pressure refrigerant from the
heat absorbing unit 104 into gas refrigerant and the liquid
refrigerant, and to supply the separated gas refrigerant to a
refrigerant suction side of the compressor 101.
[0201] As shown in FIG. 14, a heat-absorption side heat exchanger
51 is disposed in the coolant passage 31 at a coolant downstream
side of the heater core 14 to absorb heat from the coolant, and a
heat-radiation side heat exchanger 52 is disposed in the content
passage 31 at a coolant upstream side of the heater core 14 to
radiate heat to the coolant.
[0202] The heat absorbing unit 104 is thermally connected to the
heat-absorption side heat exchanger 51, so that the refrigerant in
the heat absorbing unit 104 absorbs heat from the coolant of the
engine EG via the heat-absorption side heat exchanger 51. The heat
radiator 102 is thermally connected to the heat-radiation side heat
exchanger 52, so that the refrigerant in the heat radiator 102
radiates heat to the coolant of the engine EG via the
heat-radiation side heat exchanger 52.
[0203] In the present embodiment, heat can be absorbed by the heat
pump cycle 100 via the heat-absorption side heat exchanger 51 from
the coolant after performing heat exchange with air in the heater
core 14, and heat can be radiated by the heat pump cycle 100 via
the heat-radiation side heat exchanger 52 to the coolant flowing to
the heater core 14. Therefore, the effects described in the above
first embodiment can be obtained.
[0204] The heat pump cycle 100 may be considered to absorb heat
from air, in order to heat the coolant by using the absorbed
heat.
[0205] However, when the heat pump cycle 100 absorbs heat from the
outside air, a heat pump capacity required in the heat pump cycle
100 may become larger as the outside air temperature becomes lower,
and thereby the consumed power of the heat pump cycle 100 may
become larger.
[0206] In contrast, according to the present embodiment, the heat
pump cycle 100 absorbs heat from the engine coolant that is
generally higher than the temperature of the outside air in the
winter. Thus, it is possible to increase the heat radiation amount
radiated from the heat pump cycle 100 to the coolant. As a result,
the consumed power of the heat pump cycle 100, consumed for
increasing the temperature of the coolant to a desired temperature,
can be reduced.
[0207] Furthermore, in the present embodiment, because heat is
absorbed from the coolant having a heat transmission efficiency
higher than air, the size of the heat-absorption side heat
exchanger 51 can be effectively reduced.
[0208] In the present embodiment, the heat pump cycle 100 is used
instead of the Peltier element 53 in the vehicle air conditioner 1
of the fifth embodiment. However, in the vehicle air conditioner 1
according to any one of the first to fourth embodiments and the
sixth to tenth embodiments, the heat pump cycle 100 similarly to
the eleventh embodiment may be used instead of the Peltier element
53.
[0209] In the above-described eleventh embodiment, the other parts
of the air conditioner 1 may be similar to those of the
above-described fifth embodiment.
Twelfth Embodiment
[0210] A twelfth embodiment of the invention will be described with
reference to FIGS. 15-17. FIG. 15 is a schematic diagram showing an
air conditioner 1 for a vehicle according to the twelfth embodiment
of the invention. In the above-described first embodiment, the
Peltier element 53 is provided in the second coolant passage 34.
However, in the twelfth embodiment, the element structure of the
second coolant passage 34 is changed as compared with the first
embodiment shown in FIG. 1.
[0211] A water heating electrical heater 111 is disposed in the
second coolant passage 34 at an upstream side of the second heater
core 15 in a flow direction of the coolant in the second coolant
passage 34. A flow adjustment valve 112 is disposed at a downstream
side of the second heater core 15 in the flow direction of the
coolant in the second coolant passage 34. Furthermore, a sensible
heat exchanger 113 is disposed in the coolant passage 34 to perform
heat exchange between coolants within the second coolant passage
34.
[0212] The water heating electrical heater 111 is adapted to heat
the coolant before flowing into the second heater core 15 in the
second coolant passage 34. For example, the water heating
electrical heater 111 is an electrical heater which generates heat
when an electrical power is applied thereto from a high-voltage
electrical source such as a high-voltage battery or a high-voltage
capacitor mounted to the vehicle. In this case, the high-voltage
battery may be also used for supplying electrical power to an
electrical motor for a vehicle traveling. The water heating
electrical heater 111 is controlled by the air conditioning
controller 60 to be turned on at a predetermined condition.
[0213] The flow adjustment valve 112 is configured such that its
passage sectional area is changeable. Therefore, the flow
adjustment valve 112 can adjust a flow amount of the coolant
flowing through the second coolant passage 34. As the flow
adjustment valve 112, an electrical valve or an electromagnetic
valve may be used. In the present embodiment, the operation (e.g.,
open degree) of the flow adjustment valve 112 is controlled by the
air conditioning controller 60 so that the flow amount of the
coolant flowing through the second coolant passage 34 can be
adjusted.
[0214] The sensible heat exchanger 113 is disposed in the second
coolant passage 34, such that the coolant upstream of the water
heating electrical heater 111 is heat exchanged with the coolant,
downstream of the second heater core 15, thereby performing a heat
transmission from the coolant after flowing out of the second
heater core 15 to the coolant before flowing into the water heating
electrical heater 111. As the sensible heat exchanger 113, a
generally-known heat exchanging structure may be used.
[0215] For example, a heat pipe structure or a double pipe
structure may be used as the heat exchanging structure of the
sensible heat exchanger 113. In the present embodiment, the
sensible heat exchanger 113 is a countercurrent-type heat exchanger
in which the fluid (e.g., the coolant) flows reversely in the flow
direction.
[0216] A bypass passage 114, through which the coolant flows while
bypassing the sensible heat exchanger 113 at a downstream side of
the second heater core 15, is provided in the second Coolant
passage 34, and a flow switching valve 115 is disposed to switch a
coolant path between the bypass passage 114 and a path of the
sensible heat exchanger 113.
[0217] Specifically, one end of the bypass passage 114 is connected
to a position between the flow adjustment valve 112 and the
sensible heat exchanger 113, and the other end of the bypass
passage 114 is connected to a position between the sensible heat
exchanger 113 and the join point 31b. In the present embodiment
shown in FIG. 15, the flow switching valve 115 is located at an
upstream end portion of the bypass passage 114 in the coolant flow.
However, the flow switching valve 115 may be located at a
downstream end portion of the bypass passage 114 in the coolant
flow.
[0218] FIG. 16 is a schematic diagram showing an electrical control
portion of the air conditioner 1 for a vehicle according to the
twelfth embodiment of the invention. As shown in FIG. 16, the air
conditioning controller 60 controls operation of the water heating
electrical heater 111, the flow adjustment valve 112 and the flow
switching valve 115, which are located at the output side of the
air conditioning controller 60. The air conditioning controller 60
controls ON/OFF operation of the water heating electrical heater
111, the open degree of the flow adjustment valve 112 and the
operation of the flow switching valve 115.
[0219] FIG. 17 is a flowchart for determining ON/OFF operation of
the water heating electrical heater 111, according to the present
embodiment. First, at step S21, an air temperature TA1 blown into
the vehicle compartment from an air outlet is calculated based on
the temperature TW1 of the coolant flowing into the first heater
core 14 and the temperature TW2 of the coolant flowing into the
second heater core 15. The temperature TW2 of the coolant flowing
into the second heater core 15 can be detected by the second
coolant sensor 66, and the temperature TW1 of the coolant flowing
into the first heater core 14 can be detected by the first coolant
sensor 65.
[0220] Next, at step S22, the air temperature TA1 calculated based
on the coolant temperature at step S21 is compared with the target
outlet air temperature TAO. When the air temperature TA1 is lower
than the target outlet air temperature TAO at step S22, the water
heating electrical heater 111 is turned on at step S23. In
contrast, when the air temperature TA1 is not lower than the target
outlet air temperature TAO at step S22, the water heating
electrical heater 111 is turned off at step S24.
[0221] The open degree of the flow adjustment valve 112 is
controlled such that the flow amount of the coolant is reduced
while the water heating electrical heater 111 is turned on, as
compared with the flow amount of the coolant while the water
heating electrical heater is turned off. For example, when the
water heating electrical heater 111 is not energized (OFF state),
the open degree of the flow adjustment valve 112 is set at a first
open degree such that the flow amount of the coolant flowing
through the first heater core 14 is equal to the flow amount of the
coolant flowing through the second heater core 15. When the water
heating electrical heater 111 is energized (ON state), the open
degree of the flow adjustment valve 112 is set at a second open
degree such that the flow amount of the coolant flowing through the
second heater core 15 is smaller than the flow amount of the
coolant flowing through the first heater core 14.
[0222] Furthermore, the operation of the flow switching valve 115
is controlled, such that the coolant flows through the sensible
heat exchanger 113 without flowing through the bypass passage 114
when the water heating electrical heater 111 is turned on, and the
coolant only flows through the bypass passage 114 without flowing
through the sensible heat exchanger 113 when the water heating
electrical heater 111 is turned off.
[0223] For example, when a long time elapses after the engine EG
stops, the coolant temperature may become lower, and thereby the
air temperature TA1 may become lower than the target outlet air
temperature TAO. That is, in this case, the coolant temperature may
become lower than a necessary temperature required in the heating
of the vehicle compartment.
[0224] Thus, when the coolant temperature is lower than the
necessary temperature required in the heating of the vehicle
compartment, the air conditioning controller 60 causes the water
heating electrical heater 111 to be turned on so as to heat the
coolant, and causes the flow adjustment valve 112 to be set at the
second open degree so that the flow amount of the coolant flowing
through the second heater core 15 is made smaller. Furthermore, in
this case, the air conditioning controller 60 controls the flow
switching valve 115 so that all the coolant after flowing out of
the second heater core 15 flows into the sensible heat exchanger
113. Therefore, heat can be transferred from the coolant after
flowing out of the second heater core 15 to the coolant before
flowing into the water heating electrical heater 111. In this case,
it is prefer to set the air mix door 19 at the maximum heating
position, by the air conditioning controller 60.
[0225] Thus, the temperature of the coolant flowing in the second
coolant passage 34 for the second heater core 15 can be controlled
as follows. For example, in a case where the target temperature of
air immediately after passing through the second heater core 15 is
50.degree. C., if the coolant temperature immediately after flowing
out of the engine EG is 40.degree. C., the temperature of the
coolant after passing through the sensible heat exchanger 113 is
increased to 45.degree. C. from 40.degree. C. at the upstream side
of the water-heating heat exchanger 113, and the temperature of the
coolant after passing through the water heating electrical heater
111 is increased to 70.degree. C. Because the coolant radiates heat
to air in the second heater core 15, the temperature of the coolant
at the coolant outlet of the second heater core 15 becomes
46.degree. C., and is further reduced to 41.degree. C. after
passing through the sensible heat exchanger 113 at the downstream
coolant side of the flow adjustment valve 112.
[0226] As described above, the temperature of the coolant flowing
into the second heater core 15 can be increased without operating
the engine EG, and thereby a desired heating can be performed
without operating the engine EG.
[0227] When the engine EG is operated or when an elapsed time after
the stop of the engine EG is short, the coolant temperature is
sufficiently high. In this case, if the air temperature TA1 is
equal to or higher than the target outlet air temperature TAO, it
is unnecessary to heat the engine coolant by using the operation of
the water heating electrical heater 111. In this case, the water
heating electrical heater 111 is not turned on by the air
conditioning controller 60, and the opening of the flow adjustment
valve 112 is set at the first open degree so that the flow amount
of the coolant flowing through the second heater core 15 is made
larger. Furthermore, the flow switching valve 115 is controlled so
that the coolant flowing out of the second heater core 15 flows
through the bypass passage 114 without flowing through the sensible
heat exchanger 113. In this case, the position (open degree) of the
air mix degree 19 is controlled by the air conditioning controller
60, thereby adjusting the temperature of conditioned air to be
blown into the vehicle compartment.
[0228] The operation effects of the present embodiment will be
described.
[0229] (1) According to the present embodiment, when the coolant
temperature is lower than the necessary temperature required for
the heating of the vehicle compartment, the temperature of the
coolant flowing into the second heater core 15 is increased by the
operation of the water heating electrical heater 111, instead of
the operation of the engine EG. Thus, the operation frequency of
the engine EG can be reduced, thereby improving the fuel
consumption efficiency of the engine EG, as compared with an air
conditioner without having the water heating electrical heater
111.
[0230] Generally, the temperature of the engine coolant flowing
into the second heater core 15 is preferably equal to or higher
than the necessary temperature required for the heating, e.g.,
60.degree. C. On the other hand, the temperature of the coolant
flowing into the interior of the engine EG is preferably equal to
or higher than a lower limit temperature for effectively heating
the respective parts of the engine EG. Here, the lower limit
temperature is 40.degree. C., for example.
[0231] Thus, in a conventional vehicle air conditioner without
having the water heating electrical heater 111 and the sensible
heat exchanger 113, the engine-operation required temperature is
set at a temperature around 60.degree. C. in order to keep the
coolant temperature equal to or higher than 60.degree. C.
[0232] In contrast, according to the present embodiment, when the
temperature of the engine coolant becomes lower than 60.degree. C.
while the engine EG stops, the engine. EG is not operated, but the
water heating electrical heater 111 is operated so that the
temperature of the engine coolant is increased. Thus, in the
present embodiment, it is possible to set the engine-operation
required temperature to be lower than 60.degree. C. For example,
the engine-operation required temperature can be set at a
temperature about 40.degree. C. Thus, in the present embodiment,
the engine operation required temperature can be set lower, and
thereby the operation frequency of the engine EG can be reduced,
and thereby the fuel consumption efficiency of the engine EG can be
improved.
[0233] (2) In the present embodiment, the first heater core 14 and
the second heater core 15 are arranged in parallel with respect to
the flow of the coolant, and the heat radiation portion of the
sensitive heat exchanger 113 and the water heating electrical
heater 111 are arranged upstream of the second heater core 15 in
the coolant flow. When the heat source for the heating of the
vehicle compartment is insufficient, only the coolant flowing into
the second heater core 15 is heated by the operation of the water
heating electrical heater 111, thereby effectively reducing the
consumed power of the water heating electrical heater 111.
[0234] Furthermore, the second heater core 15 is disposed to heat
air after passing through the first heater core 14. Therefore, the
air, after being heated by a low-temperature coolant in the first
heater core 14, can be further heated by a high-temperature coolant
heated by the water heating electrical heater 111, and thereby the
heat quantity can be effectively increased for the heating of
air.
[0235] (3) Furthermore, in the present embodiment, when the water
heating electrical heater 111 is turned on, the flow amount of the
coolant flowing through the second heater core 12 is made smaller
than that when the water heating electrical heater 111 is turned
off. Furthermore, when the water heating electrical heater 111 is
turned on, the flow switching valve 115 is controlled so that the
coolant flowing out of the second heater core 15 flows through the
sensible heat exchanger 113.
[0236] However, in a case where the flow adjustment valve 112 and
the sensible heat exchanger 113 are not provided, the heat quantity
without being heat-exchanged with air in the second heater core 15
may be radiated from the surface of the engine EG, and the heated
quantity of the water heating electrical heater 111 may be
uselessly consumed.
[0237] For example, in a case where the flow amount of the coolant
flowing through the first heater core 14 is the same as the flow
amount of the coolant flowing through the second heater core 15, if
the target temperature of air immediately after passing through the
second heater core 15 is 50.degree. C., the temperature of the
coolant at the coolant outlet of the second heater core 15 is about
53.degree. C. Thus, among the heat quantity obtained by the
operation of the water heating electrical heater 111, only the heat
quantity corresponding to the temperature difference of the coolant
before and after heat exchange in the second heater core 15 is
transferred to air, but the remaining heat quantity is uselessly
radiated from the engine surface, for example.
[0238] In contrast, according to the present embodiment, the flow
amount of the coolant flowing through the second heater core 15 is
made smaller when the water heating electrical heater 111 is turned
on, as compared with that when the water heating electrical heater
111 is turned off. Accordingly, as compared with a case where the
flow amount of the coolant flowing to the second heater core 15 is
larger, a ratio of the heat radiation amount from the coolant to
air in the second heater core 15 can be increased with respect to
the heat quantity due to the water heating electrical heater 111.
Thus, in the present embodiment, the temperature of the coolant at
the coolant outlet of the second heater core 15 can be decreased
because of the flow adjustment valve 112 and the sensible heat
exchanger 113. Generally, in a case where the heat radiation amount
from the coolant to air is constant, the temperature difference of
the coolant before and after the heat exchange becomes smaller as
the flow amount of the coolant is larger, and the temperature
difference of the coolant before and after the heat exchange
becomes larger as the flow amount of the coolant is smaller.
[0239] Accordingly, in the present embodiment, it can restrict the
heat quantity of the coolant, without being heat-exchanged with air
in the second heater core 15, from being radiated from the surface
of the engine EG. As a result, the heat quantity obtained by the
water heating electrical heater 111 can be effectively used.
[0240] Furthermore, heat is transferred from the coolant flowing
out of the second heater core 15 to the coolant before flowing into
the water heating electrical heater 111. Therefore, in the present
embodiment, it can further restrict the heat quantity of the
coolant, without being heat-exchanged with air in the second heater
core 15, from being radiated from the surface of the engine EG.
Because the temperature of the coolant flowing into the water
heating electrical heater 111 is increased by the sensible heat
exchanger 113, consumed electrical power of the water heating
electrical heater 111, for heating the coolant to a necessary
heating temperature, can be decreased by the temperature increase
of the coolant due to the sensible heat exchanger 113.
[0241] (4) In the present embodiment, the water heating electrical
heater 111 can be operated by using a high-voltage electrical
source for supplying an electrical power to an electrical motor for
a vehicle traveling, as an electrical source.
[0242] In this case, the water heating electrical heater 111 can be
located in an engine compartment of the vehicle, thereby preventing
an electrical shock trouble even when a high-voltage electrical
voltage is applied to the water heating electrical heater 111.
Therefore, it is unnecessary to use a DC-DC converter, thereby
preventing an electrical loss due to the DC-DC converter.
Furthermore, because the high-voltage electrical source is used,
the weight of the electrical source can be reduced as compared with
that in a case where a low-voltage electrical source is used.
[0243] In the present embodiment, at steps S22, S23, when the air
temperature TA1 calculated based on the coolant temperature at step
S21 is lower than the target outlet air temperature TAO, it is
determined that the temperature of the coolant is lower than the
necessary coolant temperature required for the heating. However,
when the coolant temperature detected by the first coolant sensor
65 or the second coolant temperature sensor 66 is lower than a
predetermined temperature, it may be determined that the
temperature of the coolant is lower than the necessary coolant
temperature required for the heating. As the predetermined
temperature, the engine-operation request temperature may be
used.
[0244] In the present embodiment, when the water heating electrical
heater 111 is turned on, the open degree of the flow adjustment
valve 112 is set at the second open degree that is smaller than the
first open degree. However, the open degree of the flow adjustment
valve 112 may be adjusted such that all the heat quantity supplied
to the coolant by the operation of the water heating electrical
heater 111 can be substantially radiated to air in the second
heater core 15.
[0245] In the above-described embodiment, the flow adjustment valve
112 is arranged in the second coolant passage 34 at a position
downstream of the second heater core 15 in the flow direction of
the second coolant. However, the flow adjustment valve 112 may be
arranged in the second coolant passage 34 at a position upstream of
the second heater core 15 in the flow direction of the second
coolant.
[0246] In the above-described embodiment, when the water heating
electrical heater 111 is turned off, the passage switching valve
115 is switched such that the coolant flows through the bypass
passage 114. However, when the temperature Ta of the coolant
flowing out of the second heater core 15 is lower than the
temperature Tb of the coolant flowing into the water heating
electrical heater 111, the flow switching valve 115 may be switched
such that the coolant flows through the bypass passage 114. That
is, in a condition where heat transmission, from the coolant
flowing out of the second heater core 15 to the coolant flowing
into the water heating electrical heater 111, cannot be performed,
the flow switching valve 115 may be switched such that the coolant
flows through the bypass passage 114 without flowing through the
sensible heat exchanger 113.
Thirteenth Embodiment
[0247] A thirteenth embodiment of the invention will be described
with reference to FIG. 18. FIG. 18 is a schematic diagram showing
an air conditioner 1 for a vehicle according to the thirteenth
embodiment of the invention. In the air conditioner 1 for a vehicle
of the thirteenth embodiment, the sensible heat exchanger 113, the
bypass passage 114 and the flow switching valve 115 are omitted
with respect to the vehicle air conditioner 1 of the
above-described twelfth embodiment.
[0248] Even in the case where the sensible heat exchanger 113 is
omitted, when the water heating electrical heater 111 is turned on,
the flow amount of the coolant flowing through the second heater
core 12 is made smaller than that when the water heating electrical
heater 111 is turned off. Thus, the heat radiation from the surface
of the engine EG can be effectively reduced. In the above-described
thirteenth embodiment, the other parts may be similar to those of
above-described twelfth embodiment.
Fourteenth Embodiment
[0249] A fourteenth embodiment of the invention will be described
with reference to FIG. 19. FIG. 19 is a schematic diagram showing
an air conditioner 1 for a vehicle according to the fourteenth
embodiment of the invention.
[0250] In the air conditioner 1 for a vehicle of the fourteenth
embodiment, the water heating electrical heater 111, the sensible
heat exchanger 113, the bypass passage 114 and the flow switching
valve 115 are omitted, and an inverter 121 is used as a water
heater instead of the water heating electrical heater 111, with
respect to the vehicle air conditioner 1 of the above-described
twelfth embodiment.
[0251] In the present embodiment, a coolant system is configured
such that the coolant flowing out of the engine EG passes through
the inverter 121, and the coolant system is switchable between a
coolant passage flowing to the second heater core 15 and a inverter
coolant circuit 120 that is a closed circuit.
[0252] In the inverter coolant circuit 120, the inverter 121, a
water pump 122, a radiator 123, a first flow switching valve 124
and a second flow switching valve 125 are provided.
[0253] The inverter 121 is generally mounted to a hybrid vehicle to
convert an electrical current, supplied from the electrical motor
for a vehicle traveling, from the direct current to alternate
current. The water pump 122 is disposed in the inverter coolant
circuit 120 so that the coolant circulates in the inverter coolant
circuit 120. The radiator 123 is a heat exchanger configured to
radiate heat from the coolant after passing through the inverter
121 to air.
[0254] Specifically, the first flow switching valve 124 and the
second flow switching valve 125 are disposed to be switched between
a first passage in which the coolant flowing out of the engine EG
passes through the inverter 121 and then flows into the second
heater core 15 as in the solid line arrows in FIG. 19, and a second
passage in which coolant circulates the inverter 121, the water
pump 122, the radiator 123 and the inverter 121 in this order as in
the chain line arrows in FIG. 19.
[0255] When the coolant temperature detected by the first coolant
temperature sensor 65 is lower than a predetermined temperature,
the air conditioning controller 60 causes the water pump 122 of the
inverter coolant circuit 120 to be stopped, and controls the first
flow switching valve 124 and the second flow switching valve 125 so
that the coolant flows to the second heater core 15 through the
first passage. At this time, the inverter 121 is controlled by the
air conditioning controller 60 via an inverter controller, so that
the converting efficiency of the inverter 121 is reduced thereby
increasing the heat generating amount of the inverter 121.
[0256] Thus, when the temperature of the coolant is lower than the
necessary temperature required for the heating of the vehicle
compartment, the heat generation amount of the inverter 121 is
increased, so that the inverter 121 can be used as a water
heater.
[0257] Even when the converting efficiency of the inverter 121 is
reduced, the electrical power supplied to the electrical motor for
a vehicle traveling is not affected, and is hardly affected to the
vehicle traveling. Thus, even when the heat generation amount of
the inverter 121 is increased, the inverter 121 is cooled by the
engine coolant, and the inverter element of the inverter 121 can be
effectively operated.
[0258] In contrast, when the coolant temperature detected by the
first coolant temperature sensor 65, located at the coolant outlet
side of the engine EG, is higher than the predetermined
temperature, the first flow switching valve 124 and the second flow
switching valve 125 are controlled so that the coolant flows in the
inverter coolant circuit 120 as in the second passage. In this
case, the inverter 121 is controlled so that the converting
efficiency of the inverter 121 is increased.
[0259] Thus, when the temperature of the coolant is lower than the
necessary temperature required for the heating of the vehicle
compartment, the coolant is circulated in the inverter coolant
circuit 120, so that the inverter 121 can be cooled by the coolant.
In this case, the coolant only flows through the first heater core
14 without flowing through the second heater core 15, so that air
is heated by the first heater core 14.
[0260] In the present embodiment, the inverter 121 is used as the
coolant heater. However, a heat generator mounted to the vehicle,
using the exhaust heat of the vehicle other than the engine EG, may
be used as the heat generator. For example, a motor generator
mounted to a hybrid vehicle or an electrical vehicle, or a fuel
cell of a hybrid vehicle provided with an engine EG and the fuel
cell may be used as the heat generator. Furthermore, the coolant
may be heated by using exhaust gas of the engine EG as the heat
source.
Fifteenth Embodiment
[0261] A fifteenth embodiment of the invention will be described
with reference to FIG. 20. FIG. 20 is a perspective view showing an
integrated heat exchanger of first and second heater cores 14, 15
according to a fifteenth embodiment of the invention.
[0262] In the fifteenth embodiment; the first and second heater
cores 14, 15 of the thirteenth embodiment are integrated, but the
flow adjustment valve 112 of the thirteenth embodiment is removed
such that the flow resistance of the coolant in the second heater
core 15 is higher than the flow resistance of the coolant in the
first heater core 14.
[0263] The integrated heat exchanger shown in FIG. 20 includes an
inlet-side first header tank 131, an inlet-side second header tank
132, an outlet-side header tank 133, a plurality of first tubes 134
extending between the inlet-side first header tank 131 and the
outlet-side header tank 133 to communicate with the inlet-side
first header tank 131 and the outlet-side header tank 133, and a
plurality of second tubes 135 extending between the inlet-side
second header tank 132 and the outlet-side header tank 133 to
communicate with the inlet-side second header tank 132 and the
outlet-side header tank 133.
[0264] The inlet-side first header tank 131 extends in a tube
stacking direction of the first tubes 134, so that the coolant
flowing into the inlet-side first header tank 131 from a coolant
inlet 131a is distributed into the first tubes 134. Similarly, the
inlet-side second header tank 132 extends in a tube stacking
direction of the second tubes 135, so that the coolant flowing into
the inlet-side second header tank 132 from a coolant inlet 132a is
distributed into the second tubes 135. The outlet-side header tank
133 is provided commonly for the first and second tubes 134, 135,
so that the coolant having passed through the first and second
tubes 134, 135 is collected in the outlet-side header tank 133.
[0265] The first heater core 14 is configured by the inlet-side
first header tank 131, the first tubes 134 and the outlet-side
header tank 133. The second heater core 15 is configured by the
inlet-side second header tank 132, the second tubes 135 and the
outlet-side header tank 133.
[0266] The second heater core 15 is configured, such that a
sectional area of the coolant passage formed in the second tube 135
is smaller than a sectional area of the coolant passage formed in
the first tube 134 of the first heater core 14. Thus, the flow
resistance of the coolant flowing through the second heater core 15
can be made larger than the flow resistance of the coolant flowing
through the first heater core 14. Alternatively/Furthermore, a
passage sectional area of the second header tank 132 of the second
heater core 15 on the coolant inlet side may be made smaller than a
passage sectional area of the first header tank 131, such that the
flow resistance of the coolant flowing in the second heater core 15
may be larger than the flow resistance of the coolant flowing in
the first heater core 14.
[0267] Furthermore, in the present embodiment, a water heating
electrical heater 111 is disposed in the second coolant passage 34
between the coolant inlet 132a of the second heater core 15 and the
branch point 31a of the coolant passage 31 for the heater cores 14,
15. At the branch point 31a, the first coolant passage 33 and the
second coolant passage 34 are branched from each other.
[0268] Because the common outlet-side header tank 133 is provided
for the first heater core 14 and the second heater core 15, the
first heater core 14 and the second heater core 15 can be
integrated by the outlet-side header tank 133. Thus, the flow
resistance of the coolant flowing through the second heater core 15
can be made larger than the flow resistance of the coolant flowing
through the first heater core 14, and thereby the flow amount of
the coolant flowing through the second heater core 15 can be made
always smaller than the flow amount of the coolant flowing through
the first heater core 14.
[0269] Thus, according to the present embodiment, the flow amount
of the coolant flowing through the second heater core 15 is made
smaller that the flow amount of the coolant flowing through the
first heater core 14 when the water heating electrical heater 111
is turned on. Accordingly, as compared with a case where the flow
amount of the coolant flowing to the second heater core 15 is equal
to the flow amount of the coolant flowing through the first heater
core 14, a ratio of the heat radiation amount from the coolant to
air in the second heater core 15 can be increased relatively with
respect to the heat quantity due to the water heating electrical
heater 111.
[0270] Accordingly, in the present embodiment, it can restrict the
heat quantity of the coolant without being heat-exchanged with air
in the second heater core 15 from being radiated from the surface
of the engine EG. As a result, the heat quantity obtained by the
water heating electrical heater 111 can be effectively used.
[0271] In the present embodiment, the flow resistance of the
coolant flowing in the second coolant passage 34 for the second
heater core 15 may be set larger than the flow resistance of the
coolant flowing in the first coolant passage 33 for the first
heater core 14. Even in this case, the flow resistance of the
coolant flowing through the second heater core 15 can be made
larger than the flow resistance of the coolant flowing through the
first heater core 14. For example, the passage sectional area of
the second coolant passage 34 for the second heater core 15 may be
set smaller than the passage sectional area of the first coolant
passage for the first heater core 14.
Sixteenth Embodiment
[0272] A sixteenth embodiment of the invention will be described
with reference to FIGS. 21 to 25C. FIG. 21 is a schematic diagram
showing an air conditioner 201 for a vehicle according to the
sixteenth embodiment of the invention. In the present embodiment,
the air conditioner 201 for a vehicle of the invention is mounted
to a so-called hybrid car which obtains a driving force for a
vehicle traveling from an internal combustion engine (engine) EG
and an electric motor for traveling.
[0273] A coolant system of the present embodiment is provided with
a first coolant circuit 210 and a second coolant circuit 220. The
first coolant circuit 210 is a coolant circuit in which coolant
after cooling a cylinder header 231 of an engine 230 flows. A first
heater core 211, a first water pump 212 and a first temperature
sensor 213 are disposed in the first coolant circuit 210. In
contrast, the second coolant circuit 220 is a coolant circuit in
which coolant after cooling a cylinder block 232 of the engine 230
flows. A second heater core 221, a second water pump 222 and a
second temperature sensor 223 are disposed in the second coolant
circuit 220. For example, the engine coolant is water, or a water
solution including an addition component. The coolant for cooling
the cylinder head 231 corresponds to a first fluid, and the coolant
for cooling the cylinder block 232 corresponds to a second fluid.
The second fluid may be the same fluid as the first fluid, or may
be different from the first fluid.
[0274] In the engine 230, the cylinder block 232 is a block body
forming a cylinder bore (e.g., cylindrical hole) in which a piston
reciprocates. In contrast, the cylinder head 231 is a block body
configured to close an opening portion at a top dead-point side of
the cylinder bore, and to define the consumption chamber.
[0275] A first coolant inlet 231a and a first coolant outlet 231b
are provided in the engine 230 at a side of the cylinder head 231.
The cylinder head 231 has therein a coolant passage in which the
coolant flows to cool the cylinder head 231. The coolant flowing
from the first coolant inlet 231a passes through the coolant
passage within the cylinder head 231, and then flows out of the
first coolant outlet 231b.
[0276] Similarly, a second coolant inlet 232a and a second coolant
outlet 232b are provided in the engine 230 at a side of the
cylinder block 232. The cylinder block 232 has therein a coolant
passage in which the coolant flows to cool the cylinder block 232.
The coolant flowing from the second coolant inlet 232a passes
through the coolant passage within the cylinder block 232, and then
flows out of the second coolant outlet 232b. In the present
embodiment, the coolant flows through the coolant passage within
the cylinder block 232, without joining with the coolant flowing
through the coolant passage within the cylinder head 231.
[0277] Each of the first heater core 211 and the second heater core
221 is a heating heat exchanger, in which the coolant flowing out
of the engine 230 is heat-exchanged with air to be blown into a
vehicle compartment, thereby heating air to be blown into the
vehicle compartment. In the present embodiment, the first heater
core 211 and the second heater core 221 are integrated so as to
form a single heating heat exchanger 202. The first heater core 211
corresponds to a first heat exchanging portion of the heating heat
exchanger 202, and the second heater core 221 corresponds to a
second heat exchanging portion of the heating heat exchanger 202,
in the present embodiment.
[0278] Furthermore, within the interior of the heating heat
exchanger 202, the coolant passage of the first heater core 211 is
provided independently from the coolant passage of the second
heater core 221. A coolant inlet 211a of the first heater core 211
is connected to the first coolant outlet 231b of the cylinder head
231 via a coolant piping. On the other hand, a coolant inlet 221a
of the second heater core 221 is connected to the second coolant
outlet 231b of the cylinder block 232 via a coolant piping.
[0279] The heating heat exchanger 202 is accommodated in an air
conditioning case defining an air passage through which air blown
by a blower flows into the vehicle compartment. The blower may be
accommodated in the air conditioning case. The heating heat
exchanger 202 is disposed in the air conditioning case to form a
bypass passage through which air bypasses the heating heat
exchanger 202. An air mix door is disposed in the air conditioning
case to adjust a mix ratio between a flow amount of air passing
through the bypass passage and a flow amount of air passing through
the heating heat exchanger 202.
[0280] FIGS. 22 and 23 are a side view and a front view showing the
heating heat exchanger 202 of the present embodiment.
[0281] As shown in FIG. 22, the second heater core 221 is located
downstream of the first heater core 211 in an air flow of the
heating heat exchanger 202. In the heating heat exchanger 202, the
first heater core 211 and the second heater core 221 are connected
with each other by a connection member 301.
[0282] Specifically, as shown in FIGS. 22 and 23, the first heater
core 211 is provided with a first inlet-side tank 211c having the
first coolant inlet 211a, a first outlet-side tank 211d having the
first coolant outlet 211b, a plurality of flat tubes 211e, and
corrugated heat-transmitting fins 211f each of which is bonded to
outer surfaces of adjacent flat tubes 211e. One end of each flat
tube 211e is connected to the first inlet-side tank 211c to
communicate with the first inlet-side tank 211c, and the other end
of each flat tube 211e is connected to the first outlet-side tank
211d to communicate with the first outlet-side tank 211d.
[0283] The flat tubes 211e and the heat-transmitting fins 211f are
stacked in a stack direction to form a first heat exchanging
portion 211g. The first heater core 211 is configured in one-way
flow type in which the coolant flows through all the flat tubes
211e in one way from the first inlet-side tank 211c to the first
outlet-side tank 211d. Thus, air passing through the first heat
exchanging portion 211g is heat exchanged with the coolant flowing
in the flat tubes 211e, to be heated by the coolant.
[0284] Similarly, the second heater core 221 is provided with a
second inlet-side tank 221c having the second coolant inlet 221a, a
second outlet-side tank 221d having the second coolant outlet 221b,
a plurality of flat tubes 221e, and corrugated heat-transmitting
fins 221f each of which is bonded to outer surfaces of adjacent
flat tubes 221e. One end of each flat tube 221e is connected to the
second inlet-side tank 221c to communicate with the second
inlet-side tank 221c, and the other end of each flat tube 221e is
connected to the second outlet-side tank 221d to communicate with
the second outlet-side tank 221d.
[0285] The flat tubes 221e and the heat-transmitting fins 221f are
stacked in a stack direction to form a second heat exchanging core
portion 221g. The second heater core 221 is configured in one-way
flow type in which the coolant flows through all the flat tubes
221e in one way from the second inlet-side tank 221c to the second
outlet-side tank 221d. Thus, air passing through the second heat
exchanging portion 221g is heat exchanged with the coolant flowing
in the flat tubes 221e, to be heated by the coolant.
[0286] In the first and second heater cores 211, 221, the plural
flat tubes 211e, 221e extend in one direction that is perpendicular
to the air flow direction and the stacking direction. Furthermore,
the flat tubes 211e of the first heater core 211 are arranged on
one line in a stacking direction, and the flat tubes 221e of the
second heater core 221 are arranged on another one line in a
stacking direction in parallel with the one line of the flat tubes
211e at a downstream air side of the flat tubes 211e. For example,
the flat surface of the flat tube 211e of the first heater core 211
may be parallel with the flat surface of the flat tube 221e of the
second heater core 221. Furthermore, the flat surface of the flat
tube 211e in the first heater core 211 may be substantially on the
same surface as the flat surface of a corresponding flat tube 221e
in the second heater core 221. The first inlet-side tank 211c and
the first outlet-side tank 211d respectively extend in the tube
arrangement direction (i.e., stacking direction) to respectively
communicate with the one ends and the other ends of the flat tubes
211e. Similarly, the second inlet-side tank 221c and the second
outlet-side tank 221d respectively extend in the tube arrangement
direction (i.e., stacking direction) to respectively communicate
with the one ends and the other ends of the flat tubes 221e.
[0287] In the example of FIGS. 22 and 23, the inlet-side tanks
211c, 22c are arranged at an upper side of the flat tubes 211e,
221e, and the outlet-side tanks 211d, 221d are arranged at a lower
side of the flat tubes 211e, 221e so that the flat tubes 211e, 221e
extend in a top-bottom direction. Furthermore, the flat tubes 211e,
221e are arranged in parallel in a vehicle left-right direction in
each of the first and second heater cores 211, 221. Thus, in the
example of FIGS. 22 and 23, coolant flows downwardly from the top
to the bottom in each of the first heater core 211 and the second
heater core 221.
[0288] Furthermore, in the present embodiment, the passage cross
section of the first heater core 211 on a surface perpendicular to
the air flow direction has the same size as that of the second
heater core 221. Thus, all air having passed through the first
heater core 211 passes through the second heater core 221.
[0289] However, in the present embodiment, the dimension of the
first heater core 211 is made larger than the dimension of the
second heater core 221 in an air flow direction, so that the heat
exchanging capacity of the first heater core 211 is made larger
than that of the second heater core 221. The dimensions of the flat
tubes 211e and the heat transmitting fins 211f of the first heater
core 211 in the air flow direction are made larger than the
dimensions of the flat tubes 221e and the heat transmitting fins
221f of the second heater core 221 in the air flow direction.
Therefore, the total heat exchanging area between air and the
coolant can be made larger in the first heater core 211, than that
in the second heater core 221.
[0290] The passage sectional area of each flat tube 211e of the
first heater core 211 is made larger than the passage sectional
area of each flat tube 221e of the second heater core 221, and
thereby the flow resistance of the coolant (fluid) flowing in the
first heater core 211 is made lower than the flow resistance of the
coolant (fluid) flowing in the second heater core 221. Therefore,
the flow amount of the coolant flowing in the first heater core 211
can be easily set larger than the flow amount of the coolant
flowing in the second heater core 221.
[0291] The connection member 301 is disposed to connect the first
and second inlet-side tanks 211c, 221c, and to connect the first
and second outlet-side tanks 211d, 221d. That is, the connection
member 301 connects the first and second heater cores 211 and 221
with each other, at positions other than the heat-exchanging core
portions 211g, 221g. Furthermore, in the present embodiment, the
connection member 301 is adapted as a spacer for forming a space
between the heat-exchanging core portions 211g, 221g.
[0292] Thus, the first heater core 211 and the second heater core
221 are connected to each other by the connection member 301 with a
space between the heat-exchanging core portions 211g, 221g in the
air flow direction. Therefore, it can prevent the coolant flowing
in the first heater core 211 and the second heater core 221 from
being directly heat-transmitted at the heat-exchanging core
portions 211g, 221g. The connection member 301 may be made of the
same material as the tanks 211c, 221c, 211d, 221d.
[0293] As shown in FIG. 21, the first temperature sensor 213 is
disposed in the first coolant circuit 210, and the second
temperature sensor 223 is disposed in the second coolant circuit
220. More specifically, the first temperature sensor 213 is
arranged between the first coolant outlet 231b of the engine 230 on
the side of the cylinder head 231 and the coolant inlet 211a of the
first heater core 211, so as to detect the temperature of the
coolant flowing out of the first coolant outlet 231b of the engine
230 on the side of the cylinder header 231. On the other hand, the
second temperature sensor 223 is arranged between the second
coolant outlet 232b of the engine 230 on the side of the cylinder
block 232 and the coolant inlet 221a of the second heater core 221,
so as to detect the temperature of the coolant flowing out of the
second coolant outlet 232b of the engine 230 on the side of the
cylinder block 232.
[0294] The first water pump 212 and the second water pump 222 are
disposed to circulate the coolant respectively in the first and
second coolant circuits 210, 220, and to adjust the flow amount of
the coolant flowing in each of the first and second coolant
circuits 210, 220. The first water pump 212 is arranged in the
first coolant circuit 210 between the coolant outlet 211b of the
first heater core 211 and the first coolant inlet 231a of the
cylinder head 231 of the engine 230. The second water pump 222 is
arranged in the second coolant circuit 220 between the coolant
outlet 221b of the second heater core 221 and the second coolant
inlet 232a of the cylinder block 232 of the engine 230.
[0295] The first water pump 212 and the second water pump 222 are
electrical pumps. The rotational speeds of the first water pump 212
and the second water pump 222 are controlled so as to control
respectively the flow amounts of the coolant circulating in the
first coolant circuit 210 and the second coolant circuit 220. In
the present embodiment, during a general operation of the engine
230, the first water pump 212 and the second water pump 222 are
controlled such that the flow amount of the coolant flowing in the
coolant passage of the cylinder head 231 is larger than the flow
amount of the coolant flowing in the coolant passage of the
cylinder block 232. Thus, it is possible to keep the temperature of
the cylinder head 231 at a low temperature while improving
knocking-resistance performance. At the same time, the temperature
of the cylinder block 232 can be kept at a high temperature,
thereby preventing a viscosity decrease of an engine oil and
preventing a friction increase in the interior of the engine
230.
[0296] In the first coolant circuit 210 of the present embodiment,
the coolant flowing out of the first coolant outlet 231b of the
cylinder head 231 of the engine 230 flows into the first heater
core 211, is heat-exchanged with air in the first heater core 211,
and then flows into the engine 230 from the first coolant inlet
231a on the side of the cylinder head 231.
[0297] In the second coolant circuit 220 of the present embodiment,
the coolant flowing out of the second coolant outlet 232b of the
cylinder head 232 of the engine 230 flows into the second heater
core 221, is heat-exchanged with air in the second heater core 221,
and then flows into the engine 230 from the second coolant inlet
232a on the side of the cylinder block 232.
[0298] The first and second coolant circuits 210, 220 are
configured to communicate with a radiator (not shown), such that
the coolant flowing out of the cylinder head 231 is radiated in the
radiator and the coolant after heat radiation flows into the
cylinder head 231, and the coolant flowing out of the cylinder
block 232 is radiated in the radiator and the coolant after heat
radiation flows into the cylinder block 232.
[0299] Next, operation of the air conditioner 201 according to the
present embodiment will be described.
[0300] In the present embodiment, the first water pump 212 and the
second water pump 222 are controlled by the controller such that
the flow amount of the coolant flowing in the coolant passage of
the cylinder head 231 is larger than the flow amount of the coolant
flowing in the coolant passage of the cylinder block 232.
[0301] Furthermore, in a heating operation of the vehicle
compartment (i.e., a space to be heated), the blower is controlled
by the controller to an air blowing amount that is determined in
accordance with a target outlet air temperature TAO. The target
outlet air temperature TAO is a target temperature of air to be
blown into the vehicle compartment, and can be calculated based on
a set temperature and an air-conditioning load relative to the
environmental conditions. For example, the target outlet air
temperature TAO can be calculated similarly to that of the
above-described first embodiment.
[0302] FIG. 24 is a graph showing a temperature variation in air
passing through the first and second heater cores 211, 221
according to the sixteenth embodiment, and a comparison
example.
[0303] In the first heater core 211, the coolant after cooling the
cylinder head 231 is heat-exchanged with air passing therethrough,
thereby heating the air. The temperature of the coolant after
cooling the cylinder head 231 may be lower than the lowest
temperature required for the heating. However, the flow amount of
the coolant flowing in the cylinder head 231 is relatively large,
and thereby the coolant having a large heat quantity flows into the
first heater core 211 from the cylinder head 231. In the present
embodiment, the flow amount of the coolant flowing in the first
heater core 211 is made larger than the flow amount of the coolant
flowing in the second heater core 221, and the heat exchanging area
of the first heater core 211 is made larger than the heat
exchanging area of the second heater core 221. Therefore, a large
amount of heat quantity of the coolant after cooling the cylinder
head 231 can be transferred to air in the first heater core 211.
Therefore, a large amount of heat quantity can be supplied from the
large amount coolant after passing through the cylinder head 231 to
air. As a result, the temperature of air A1 after passing through
the first heater core 211 can be approached to a coolant
temperature Th1 before flowing into the first heater core 211. For
example, the coolant temperature Th1 is a coolant temperature at
the coolant inlet 211a of the first heater core 211, as shown in
FIG. 24.
[0304] In the second heater core 221, the coolant after cooling the
cylinder block 232 is heat-exchanged with air A1 having passed
through the first heater core 211, thereby further heating the air
A1. The coolant after cooling the cylinder block 232 has a high
temperature higher than the temperature of the coolant after
cooling the cylinder head 231. Therefore, the air A1 after passing
through the first heater core 211 can be further heated by the
second heater core 221, and the temperature of air A2 after passing
through the second heater core 221 can be increased to a
temperature higher than the temperature of air A1. As shown in FIG.
24, the temperature of the air A2 after passing through the second
heater core 221 can be increased to a temperature near a coolant
temperature Th2 flowing into the coolant inlet 221a of the second
heater core 221.
[0305] In a comparison example 1 shown in FIG. 24, coolant after
cooling the cylinder head 231 and coolant after cooling the
cylinder block 232 are joined in the interior of the engine, and
the joined coolant flows into a single heater core from a single
coolant outlet provided in the engine. In the comparison example 1,
the flow amount of the coolant flowing in the cylinder head is made
larger than the flow amount of the coolant flowing in the cylinder
block. However, in the comparison example 1, the temperature of air
cannot be sufficiently increased, as compared with the present
embodiment.
[0306] In contrast, according to the present embodiment, the first
and second coolant circuits 210, 220 are independently provided as
two separate coolant systems. Furthermore, the first water pump 212
and the second water pump 222 are controlled such that the flow
amount of the coolant flowing in the coolant passage of the
cylinder head 231 is larger than the flow amount of the coolant
flowing in the coolant passage of the cylinder block 232, in the
general operation of the engine 230. Therefore, in the general
operation of the engine 230, the cylinder head 231 can be
effectively cooled. Thus, the temperature of the coolant after
cooling the cylinder head 231 may be lower than the lowest
temperature required for the heating, but the temperature of the
coolant after cooling the cylinder block 232 can become higher than
the lowest temperature required for the heating.
[0307] If the coolant after passing through the cylinder head 231
and the coolant after passing through the cylinder block 232 are
completely mixed as in the comparison example 1 of FIG. 24, the
temperature of the mixed coolant may become lower than the lowest
temperature required for the heating. In this case, the heat
transmitting efficiency from the coolant to air becomes lower, and
thereby the temperature of air cannot be sufficiently heated by
using the mixed coolant as the heat source.
[0308] In the present embodiment, the first coolant outlet 231b and
the second coolant outlet 232b are provided in the engine 230, such
that low temperature coolant after cooling the cylinder head 231
flows out of the first coolant outlet 231b, and high temperature
coolant after cooling the cylinder block 232 flows out of the
second coolant outlet 232b. Thus, the low temperature coolant
flowing out of the first coolant outlet 231b flows into the first
heater core 211, and the high temperature coolant flowing out of
the second coolant outlet 232b flows into the second heater core
221, without mixing therebetween.
[0309] In the present embodiment, the air having passed through the
first heater core 211 is heated by using the high temperature
coolant flowing out of the second coolant outlet 232b as the heat
source in the second heater core 221. Thus, the temperature of air
after being heated in the first heater core 211 can be effectively
increased by the second heater core 221, as compared with a case
where the air is heated by only using the low temperature coolant
flowing out of the first coolant outlet 231b or a case where the
air is heated by using the mixture of the low temperature coolant
and the high temperature coolant as the heat source.
[0310] In the present embodiment, after air is heated by the low
temperature coolant as the heat source in the first heater core
211, the heated air is further heated by the high temperature
coolant as the heat source in the second heater core 221, thereby
effectively using both of heat quantities of the low temperature
coolant and the high temperature coolant.
[0311] Thus, in the present embodiment, the energy transmission
efficiency from the coolant to air in the entire first and second
heater cores 211, 221 can be effectively increased, as compared
with a case where the air to be blown into the vehicle compartment
is heated by using the mixture of the coolants flowing out of the
first and second coolant outlets 231b, 232b as the heat source in a
single heater core.
[0312] As a result, even when the air blowing amount of the blower
is large, the air can be sufficiently heated to a high temperature,
thereby effectively performing the heating of the passenger
compartment.
[0313] Furthermore, in the present embodiment, the fuel consumption
amount consumed in the vehicle air conditioner can be reduced as
shown in FIGS. 25A, 25B and 25C. FIGS. 25A, 25B and 25C show heat
loss of the coolant from the surface of the engine 230, an average
temperature in a combustion chamber of the engine 230 and an actual
fuel combustion rate, in the sixteenth embodiment and a comparison
example 2. In the comparison example 2, the flow amount of the
coolant flowing to the cylinder head 231 is made the same as the
flow amount of the coolant flowing to the cylinder block 232, and
the temperature of the coolant after cooling the cylinder head 231
is made equal to the temperature of the coolant after cooling the
cylinder block 232.
[0314] According to the present embodiment, the heating heat
quantity can be made the same as the comparison example 2, while
heat loss from the cylinder head 231 of the engine 230 can be
reduced, as shown in FIG. 25A.
[0315] Furthermore, in the present embodiment, the average
temperature in the combustion chamber of the engine 230 can be
reduced as compared with the comparison example 2, as shown in FIG.
25B. Therefore, in the present embodiment, the fuel consumption
rate can be reduced as compared with the comparison example 2, as
shown in FIG. 25C.
Seventeenth Embodiment
[0316] A seventeenth embodiment of the invention will be described
with reference to FIG. 26. FIG. 26 is a side view showing a heating
heat exchanger 202 of the seventeenth embodiment. In the present
embodiment, a common outlet-side tank is provided with respect to
the heating heat exchanger 202 described in the sixteenth
embodiment.
[0317] Specifically, in the heating heat exchanger 202 of the
present embodiment, as shown in FIG. 26, a common tank 202d is
provided to connect a coolant outlet side of the first
heat-exchanging core portion 211g of the first heater core 211 and
a coolant outlet side of the second heat-exchanging core portion
221g of the second heater core 221. Furthermore, the common tank
202d is provided, with a single coolant outlet 202b.
[0318] Thus, the low temperature coolant flowing from the coolant
inlet 211a of the first heater core 211 and the high temperature
coolant flowing from the coolant inlet 221a of the second heater
core 221 are joined in the common tank 202d, and then the joined
coolant flows out of the single coolant outlet 202b.
[0319] Therefore, the coolant after passing through the first
heat-exchanging core portion 211g of the first heater core 211 and
the coolant after passing through the second heat-exchanging core
portion 221g are joined adjacent to the coolant outlet 202b of the
heating heat exchanger 202.
[0320] In the present embodiment, the coolant flowing out of the
coolant outlet 202b of the common tank 202d is branched at a
coolant branch portion, and then the branched coolants respectively
flow into the first coolant inlet 231a and the second coolant inlet
232a of the engine 230. In the present embodiment, the other parts
may be similar to those of the above-described sixteenth
embodiment.
Eighteenth Embodiment
[0321] An eighteenth embodiment of the invention will be described
with reference to FIG. 27. FIG. 27 is a side view showing a heating
heat exchanger 202 of the eighteenth embodiment. In the present
embodiment, as shown in FIG. 27, a common tank 202d is provided to
connect a coolant inlet side of the first heat-exchanging core
portion 211g of the first heater core 211 and a coolant outlet side
of the second heat-exchanging core portion 221g of the second
heater core 221. That is, a coolant inlet 202a of the first heater
core 211 is provided in the common tank 202d used in common for the
first and second heater cores 211, 221, and an outlet side tank
211d of the first heater core 211 is provided adjacent to the inlet
side tank 221c of the second heater core 221.
[0322] The coolant inlet 202a provided in the common tank 202d is
connected to the first coolant outlet 231b of the cylinder head 231
of the engine 230 shown in FIG. 21 via piping.
[0323] Thus, the high temperature coolant having passed through the
second heat-exchanging core portion 221g of the second heater core
221 is joined with low temperature coolant flowing from the first
coolant outlet 231b of the engine 230 to the coolant inlet 202a in
the common tank 202d. Then, the joined coolant flows through the
first heat-exchanging core portion 211g of the first heater core
211 from the common tank 202d, and thereafter flows out of the
coolant outlet 211b provided in the outlet side tank 211d of the
first heater core 211.
[0324] Accordingly, in the present embodiment, the high temperature
coolant flows through the second heater core 221, and the mixture
of the low temperature coolant from the first coolant outlet 231b
of the engine 230 and the high temperature coolant having passed
through the second heater core 221 flows into the heat-exchanging
core portion 211g of the first heater core 211. Therefore, the
temperature of the coolant flowing in the second heater core 221
can be made higher than the temperature of the coolant flowing in
the heat-exchanging core portion 211g of the first heater core 211,
thereby effectively performing the heating of air to be blown into
the vehicle compartment. In the present embodiment, the other parts
may be similar to those of the above-described sixteenth
embodiment.
Nineteenth Embodiment
[0325] A nineteenth embodiment of the invention will be described
with reference to FIGS. 28 and 29. FIGS. 28 and 29 are a side view
and a front view showing a heating heat exchanger 202 disposed in
an air conditioning case 203 of the present embodiment.
[0326] In the heating heat exchanger 202 of the present embodiment,
the first heater core 211 and the second heater core 221 are
arranged in parallel with respect to a flow direction of air
passing through the air passage in the air conditioning case 203.
In the examples of FIGS. 28 and 29, the first heater core 211 is
arranged at an upper side in the air passage of the air
conditioning case 203, and the second heater core 221 is arranged
at a lower side in the air passage of the air conditioning case
203, in a top-bottom direction of the vehicle. A lower end portion
of the first heater core 211 is connected to an upper end portion
of the second heater core 221 by a connection member 301, such that
a space is formed between the first heater core 211 and the second
heater core 221.
[0327] A partition wall 203a is provided in the air conditioning
case 203 at a position downstream of the heating heat exchanger
202, so as to partition the air passage of the air conditioning
case 203 into a first passage communicating with a defroster air
outlet 204a (DEF) and a second passage communicating with a foot
air outlet 204b (FOOT). In the present embodiment, conditioned air
is blown toward an inner surface of a windshield of the vehicle
through the defroster air outlet 204a that is adapted as a first
air outlet, and conditioned air is blown toward a lower side of a
passenger in the vehicle compartment through the foot air outlet
204b that is adapted as a second air outlet. The first passage
communicating with the defroster air outlet 204a is positioned at
an upper side, and the second passage communicating with the foot
air outlet 204b is positioned at a lower side in the air
conditioning case 203, in the vehicle top-bottom direction. Thus,
air B1 after passing through the first heater core 211 mainly flows
to the first passage communicating with the defroster air outlet
204a, and air 82 after passing through the second heater core 221
mainly flows to the second passage communicating with the foot air
outlet 204b.
[0328] Furthermore, in the present embodiment, the structure of the
first heater core 211 and the structure of the second heater core
221 are respectively similar to those in the above-described
sixteenth embodiment.
[0329] In the examples of FIGS. 28 and 29, the thickness of the
first heater core 211 in the air flow direction is the same as the
thickness of the second heater core 221, but the dimensions of the
heat exchanging core portions 211g and 221g in the vehicle
top-bottom direction are made to be different from each other.
Specifically, the dimension of the flat tube 211e and the heat
transmitting fin 211f extending in the vehicle top-bottom direction
is made longer than the dimension of the flat tube 221e and the
heat transmitting fin 221f extending in the vehicle top-bottom
direction. Therefore, the heat exchanging area between air and the
coolant can be made larger in the first heater core 211, than that
in the second heater core 221.
[0330] Accordingly, the passage sectional area of each flat tube
211e of the first heater core 211 can be made larger than the
passage sectional area of each flat tube 221e of the second heater
core 221, and thereby the flow resistance of the coolant (fluid)
flowing in the first heater core 211 can be made lower than the
flow resistance of the coolant (fluid) flowing in the second heater
core 221.
[0331] Thus, in the present embodiment, in a heating operation, the
air to be blown to the defroster air outlet 204a can be heated by
using a large amount coolant after cooling the cylinder head 231,
as the heat source. In contrast, in the heating operation, the air
to be blown to the foot air outlet 204a can be heated by using the
high temperature coolant after cooling the cylinder block 232, as
the heat source.
[0332] Accordingly, relatively low-temperature warm air can be
blown toward the windshield from the defroster air outlet, and at
the same time, relatively high-temperature warm air can be blown
toward the passage from the foot air outlet. Therefore, it is
possible to set a temperature difference between the temperature of
air blown to the defroster air outlet and the temperature of air
blown to the foot air outlet.
Twentieth Embodiment
[0333] A twentieth embodiment of the invention will be described
with reference to FIGS. 30 and 31. FIGS. 30 and 31 are a side view
and a front view showing a heating heat exchanger 202 of the
present embodiment. In the present embodiment, as shown in FIGS. 30
and 31, a single coolant outlet is provided with respect to the
heating heat exchanger 202 of the above-described nineteenth
embodiment shown in FIGS. 28 and 29.
[0334] Specifically, in the heating heat exchanger 202 of the
present embodiment, communication portions 302, 303 are provided to
communicate the outlet side tank 211d of the first heater core 211
and the outlet side tank 221d of the second heater core 221 with
each other, without providing a special coolant outlet in the
outlet side tank 211d of the first heater core 211.
[0335] Thus, in the present embodiment, the coolant after passing
through the heat-exchanging core portion 211g of the first heater
core 211 flows into the communication portions 302, 303, and is
joined with the coolant after passing through the heat-exchanging
core portion 221g of the second heater core 221 in the outlet side
tank 221d of the second heater core 221. Then, the joined coolant
flows out of heating heat exchanger 202 from the coolant outlet
221b of the outlet side tank 221d of the second heater core
221.
[0336] As described above, even in the heating heat exchanger 202
in which the first heater core 211 and the second heater core 221
are arranged in parallel with respect to the air flow direction,
the coolant after passing through the first heat-exchanging core
portion 211g of the first heat core 211 and the coolant after
passing through the second heat-exchanging core portion 221g of the
second heater core 221 can be joined at a portion adjacent to the
coolant outlet 221b of the heating heat exchanger 202.
Twenty-First Embodiment
[0337] A twenty-first embodiment of the invention will be described
with reference to FIG. 32. FIG. 32 is a side view showing a heating
heat exchanger 202 of the twenty-first embodiment. The twenty-first
embodiment corresponds to a combination of the above-described
sixteenth embodiment and nineteenth embodiment. That is, the
partition wall 203a, the defroster air outlet 204a and the foot air
outlet 204b are provided similar to the nineteenth embodiment shown
in FIG. 28. Specifically, as shown in FIG. 32, a first heater core
211 is disposed in the air conditioning case 203 to across all the
air passage of the air conditioning case 203, and a second heater
core 221 is located in the air conditioning case 203 downstream of
the first heater core 211 in the air flow direction to be opposite
to a part of the downstream surface of the first heater core 211.
Thus, a part of air having passed through the first heater core 211
flows into the second heater core 221, and the other part of air
having passed through the first heater core 211 bypasses the second
heater core 221.
[0338] The dimension of the heat-exchanging core portion 221g of
the second heater core 221 in the top-bottom direction is made
shorter than the dimension of the heat-exchanging core portion 211g
of the first heater core 211 in the top-bottom direction, and is
arranged at the lower side in the air passage of the air
conditioning case 203.
[0339] Therefore, in the heating operation of the present
embodiment, a relatively low-temperature air heated by only the
first heater core 211 can be blown toward the defroster air outlet
204a, and relatively high-temperature air heated by both the first
heater core 211 and the second heater core 221 can be blown toward
the foot air outlet 204b. As a result, the temperature of air to be
blown into the foot air outlet 204b can be more increased as
compared with the nineteenth embodiment. In the present embodiment,
other parts may be similar to those of the above-described
sixteenth embodiment.
Twenty-Second Embodiment
[0340] A twenty-second embodiment of the invention will be
described with reference to FIG. 33. FIG. 33 is a schematic diagram
showing an air conditioner for a vehicle according to the
twenty-second embodiment of the invention. In the above-described
sixteenth to twenty-first embodiments, the coolant after cooling
the cylinder head 231 of the engine 230 is used as the
low-temperature side coolant, and the coolant after cooling the
cylinder block 232 of the engine 230 is used as the
high-temperature side coolant. However, in the twenty-second
embodiment, coolant of the engine 230 is used as the low
temperature coolant, and coolant of an inverter 241 is used as the
high temperature coolant. Thus; the coolant of the engine 230
corresponds to the first fluid, and the coolant of the inverter 241
corresponds to the second fluid.
[0341] As shown in FIG. 33, a heating heat exchanger 202 of the
present embodiment includes a first heater core 211 arranged at an
upstream air side in an air conditioning case 203, and a second
heater core 221 arranged at a downstream air side of the first
heater core 211 in the air conditioning case 203, similarly to the
above-described sixteenth embodiment.
[0342] The first heater core 211 is disposed in an engine coolant
circuit so that the coolant after cooling the engine 230 flows into
the first heater core 211. Thus, a single coolant outlet is
provided for the heating heat exchanger 202, in the engine 230.
[0343] On the other hand, the second heater core 221 is provided in
an inverter coolant circuit 240, so that the coolant in the
inverter coolant circuit 240 flows into the second heater core 221.
The inverter coolant circuit 240, in which the coolant for cooling
the inverter 241 circulates, is a coolant circuit provided
independently from the engine coolant circuit. The inverter coolant
circuit 240 is provided with the inverter 241, a water pump 242, a
radiator 243, a thermostat 244.
[0344] The inverter 241 is an electrical machine mounted to a
hybrid vehicle, and is adapted to convert an electrical current
supplied to an electrical motor for a vehicle traveling from the
direct current to the alternate current. The water pump 242 is
disposed in the inverter coolant circuit 240 so that the coolant
circulates in the inverter coolant circuit 240. The radiator 243 is
a heat exchanger configured to radiate heat from the coolant after
passing through the inverter 241 to air. The thermostat 244 is a
flow opening/closing unit that opens or closes a coolant passage
through which the coolant flows to the radiator 243.
[0345] Generally, in the hybrid vehicle, the engine 230 may be
stopped in accordance with a traveling load of the vehicle.
[0346] In the present embodiment, if a controller (not shown)
determines that the temperature of the coolant flowing out of the
engine 230 is lower than a necessary lowest temperature required
for the heating in the beating operation and determines that the
temperature of air after passing through the first heater core 211
cannot be sufficiently increased, a converting efficiency of the
inverter 241 is decreased so that the inverter 241 is adapted as a
heat generating member. Thus, the temperature of the coolant
flowing into the second heater core 221 can be made higher than the
temperature of the coolant flowing into the first heater core 211,
thereby further increasing the temperature of air to be blown
toward the vehicle compartment. Furthermore, in a case where the
temperature of the coolant of the inverter 241 is too increased,
the coolant in the inverter coolant circuit is cooled by the
radiator 243, thereby preventing a trouble caused in the inverter
241.
[0347] In the present embodiment, as the high temperature coolant,
the coolant of the inverter 241 is used. However, coolant of a heat
generator mounted to the vehicle to use the exhaust heat of the
vehicle, other than the engine EG, may be used as the high
temperature coolant. For example, coolant, for cooling an
electrical machine such as a generator and a battery mounted on a
hybrid vehicle or an electrical vehicle, may be used as the heat
source for the heating of air to be blown into the vehicle
compartment.
[0348] Furthermore, hot water of a hot water circuit heated by a
heating unit other than the engine may flow into the second heater
core 221. As the heating unit, a water-heating electrical heater, a
heat pump, an exhaust heat of an exhaust gas or the like may be
used. In this case, it is prefer for the flow amount of the coolant
flowing through the second heater core 221 to be smaller than the
flow amount of the coolant flowing through the first heater core
211. In the above-described twenty-second embodiment, the inverter
coolant circuit is configured separately from the engine coolant
circuit. However, the inverter coolant circuit may be configured to
be connected to the engine coolant circuit, so that a part of the
engine coolant circuit flows into the inverter coolant circuit.
Other Embodiments
[0349] Although the present invention has been fully described in
connection with the preferred embodiments thereof with reference to
the accompanying drawings, it is to be noted that various changes
and modifications will become apparent to those skilled in the
art.
[0350] (1) In the above-described embodiments, the air conditioner
according to the invention is used for a hybrid car having an
engine EG and an electrical motor for a vehicle traveling. However,
the air conditioner according to the invention may be suitably used
for an idling-stop vehicle or other kinds of vehicles such as a
fuel cell vehicle or an electrical vehicle that has a vehicle
driving source other than the engine EG.
[0351] For example, in the air conditioner for a fuel cell vehicle
provided with a fuel cell and an electrical motor, air to be blown
into the vehicle compartment is heated in a heating heat exchanger
by using coolant of the fuel cell as a heat source.
[0352] (2) In the above-described sixteenth embodiment, the
heat-exchanging core portion 211g of the first heater core 211 and
the heat-exchanging core portion 221g of the second heater core 221
are spaced from each other in the air flow direction in the whole
area of the heat-exchanging core portions 211g, 221g. However, the
heat-exchanging core portion 211g of the first heater core 211 and
the heat-exchanging core portion 221g of the second heater core 221
may be partially spaced from each other so that a part area can be
connected therebetween. Even in this case, the heat transmission
between the heat-exchanging core portion 211g of the first heater
core 211 and the heat-exchanging core portion 221g of the second
heater core 221 can be reduced as compared with a case where the
all area are connected to each other.
[0353] (3) In the above-described sixteenth embodiment, the flow
direction of the coolant in the first heater core 211 is made the
same as that in the second heater core 221, such that the coolant
flows from the top side to the bottom side in the heat-exchanging
core portions 211g, 221g. However, the flow direction of the
coolant in the first heater core 211 can be made reversely to the
flow direction of the coolant in the second heater core 221.
[0354] (4) In the above-described nineteenth to twenty-first
embodiment of the invention, the air after passing through the
first heater core 211 mainly flows to the first passage
communicating with the defroster air outlet 204a. However, the air
after passing through the first heater core 211 may flow to the
first passage communicating with a face air outlet through which
air is blown toward an upper side of the vehicle compartment. Thus,
relatively low-temperature air can be blown toward an upper side of
the vehicle compartment or the windshield, while relatively
high-temperature air can be blown toward a lower side of the
vehicle compartment.
[0355] Alternatively, in a case where only a driver is seated on
the driver's seat of the vehicle and no other passenger is on the
seat other than the driver's seat of the vehicle, the relatively
high-temperature air after passing through the second heater core
221 can be blown toward the driver of the vehicle compartment, and
the relatively low-temperature air after passing through the first
heater core 211 can be blown toward the seats other than the
driver's seat in the vehicle compartment.
[0356] (5) In the above-described sixteenth to twenty-first
embodiments, only the coolant for cooling the cylinder head 231
flows out of the first coolant outlet 231b of the engine 230.
However, a part of the coolant for cooling the cylinder block 232
may be mixed with the coolant for cooling the cylinder head 231,
and the mixed coolant may flows from the first coolant outlet 231b
of the engine 230 to the first heater core 211. That is, the
coolant mainly cooling the cylinder head 231 in the engine 230 may
flows out of the first coolant outlet 231b of the engine 230 to the
first heater core 211.
[0357] Similarly, in the above-described sixteenth to twenty-first
embodiments, only the coolant for cooling the cylinder block 232
flows out of the second coolant outlet 232b of the engine 230.
However, a part of the coolant for cooling the cylinder head 231
may be mixed with the coolant for cooling the cylinder block 232,
and the mixed coolant may flows from the second coolant outlet 232b
of the engine 230 to the second heater core 221. Thus, the coolant
mainly cooling the cylinder block 232 in the engine 230 may flows
out of the second coolant outlet 232b of the engine 230 to the
second heater core 221, while the coolant mainly cooling the
cylinder head 231 in the engine 230 may flows out of the first
coolant outlet 231b of the engine 230 to the first heater core 211.
Even in this case, the temperature of the coolant flowing out of
the second coolant outlet 232b in the engine 230 can be made higher
than the temperature of the coolant flowing out of the first
coolant outlet 231b in the engine 230.
[0358] For example, a part of the coolant after cooling the
cylinder head 231 may be mixed with the coolant after cooling the
cylinder block 232 in the engine 230, and the mixed coolant may
flow out of the second coolant outlet 232 of the engine 230 to flow
into the second heater core 221. Even in this case, the temperature
of the coolant flowing into the second heater core 221 can be
increased more than the temperature of the coolant flowing into the
first heater core 211.
[0359] (6) In the above-described sixteenth embodiment, only the
coolant flowing out of the second coolant outlet 232b of the engine
230 flows into the second heater core 221. However, a part of the
coolant flowing out of the first coolant outlet 231b may be mixed
with the coolant after flowing out of the second coolant outlet
232b, and the mixed coolant may flow into the second heater core
221.
[0360] Even in this case, the temperature of the coolant flowing
into the second heater core 221 can be made higher than the
temperature of the coolant flowing into the first heater core 211,
thereby effectively increasing the temperature of air to be blown
toward the vehicle compartment.
[0361] (7) In the above-described sixteenth to the twenty-second
embodiments, the flow amount of the coolant flowing through the
first heater core 211 is made larger than the flow amount of the
coolant flowing through the second heater core 221. However, the
flow amount of the coolant flowing through the first heater core
211 may be made equal to the flow amount of the coolant flowing
through the second heater core 221
[0362] For example, in the structure of the above-described
sixteenth embodiment, a part of the low temperature coolant flowing
out of the first coolant outlet 231b of the engine 230 may be
joined with the high temperature coolant flowing out of the second
coolant outlet 232b, such that the flow amount of the coolant
flowing through the first heater core 211 is equal to the flow
amount of the coolant flowing through the second heater core
221.
[0363] (8) In the above-described sixteenth to twenty-first
embodiments, the air conditioner of the present embodiment may be
applied to a vehicle having an internal combustion engine; however,
may be applied to a vehicle in which exhaust heat of an equipment
other than the internal combustion engine is used as the heat
source for the heating. For example, a heat generating member that
generates heat when being operated may be used instead of the
internal combustion engine.
[0364] (9) In the above-described embodiments, the coolant is used
as a cooling fluid for cooling a heat generating member such as an
engine mounted to a vehicle. However, as the cooling fluid, a
cooling liquid other than water or a gas fluid may be used without
being limited to the coolant.
[0365] (10) The above described embodiments may be suitably
combined if there is no contradiction therebetween.
[0366] Such changes and modifications are to be understood as being
within the scope of the present invention as defined by the
appended claims.
* * * * *