U.S. patent application number 14/002335 was filed with the patent office on 2013-12-19 for vehicle air-conditioning apparatus.
This patent application is currently assigned to Toyota Jidosha Kabushiki Kaisha. The applicant listed for this patent is Masaki Morita. Invention is credited to Masaki Morita.
Application Number | 20130333395 14/002335 |
Document ID | / |
Family ID | 46797613 |
Filed Date | 2013-12-19 |
United States Patent
Application |
20130333395 |
Kind Code |
A1 |
Morita; Masaki |
December 19, 2013 |
VEHICLE AIR-CONDITIONING APPARATUS
Abstract
An air conditioning apparatus cools air sent to a passenger
compartment by using a cooling machine which is a vapor compression
heat pump. Heating of the air may be implemented by utilizing the
heat of an internal combustion engine or via a Peltier element. As
the cooling machine, a cooling machine provided in a conventional
air conditioning apparatus may be utilized, thus eliminating the
need for significant modification of the structure of the air
conditioning apparatus. The air sent to the passenger compartment
can be heated with the Peltier element so that the passenger
compartment can be air-conditioned (heated), even when it is
difficult to utilize the internal combustion engine as a heat
source for air-conditioning the passenger compartment, such as when
the vehicle is travelling solely on the motor generator. Thus, the
passenger compartment can be air-conditioned in vehicles in which
it is difficult to utilize the internal combustion engine as a heat
source for air-conditioning the passenger compartment, without
requiring significant structural changes.
Inventors: |
Morita; Masaki; (Toyota-shi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Morita; Masaki |
Toyota-shi |
|
JP |
|
|
Assignee: |
Toyota Jidosha Kabushiki
Kaisha
Toyota-shi
JP
|
Family ID: |
46797613 |
Appl. No.: |
14/002335 |
Filed: |
March 4, 2011 |
PCT Filed: |
March 4, 2011 |
PCT NO: |
PCT/JP2011/055132 |
371 Date: |
August 29, 2013 |
Current U.S.
Class: |
62/3.61 |
Current CPC
Class: |
B60H 1/00478 20130101;
F25B 21/02 20130101; B60H 1/00899 20130101; B60H 1/004
20130101 |
Class at
Publication: |
62/3.61 |
International
Class: |
F25B 21/02 20060101
F25B021/02 |
Claims
1. A vehicle air-conditioning apparatus for adjusting a temperature
in a passenger compartment by cooling or heating air sent to the
passenger compartment, the vehicle air-conditioning apparatus
comprising: a cooling device that cools the air sent to the
passenger compartment; and a Peltier element that heats the air
sent to the passenger compartment.
2. The vehicle air-conditioning apparatus according to claim 1,
comprising a circulation circuit that circulates coolant performing
heat transfer with an internal combustion engine mounted on a
vehicle, and heats air sent to the passenger compartment by the
coolant, wherein the Peltier element includes a heating portion
that heats the coolant in the circulation circuit, the Peltier
element heating the air sent to the passenger compartment through
the heating operation by the heating portion.
3. The vehicle air-conditioning apparatus according to claim 2,
wherein the circulation circuit includes a first path that allows
the coolant circulating in the circulation circuit to pass through
the internal combustion engine and a second path that allows the
coolant to bypass the internal combustion engine, and either one of
the first path and the second path is used as a path for
circulating the coolant.
4. The vehicle air-conditioning apparatus according to claim 2,
wherein the circulation circuit includes a radiator, when the
temperature of the coolant circulating in the circulation circuit
is greater than or equal to a predetermined determination value,
the radiator allows to flow therein to perform heat transfer
between the coolant and ambient air, the Peltier element includes a
cooling portion that performs heat transfer with the coolant
circulating in a coolant circuit, and when the internal combustion
engine is stopped and the heating operation of the heating portion
of the Peltier element is performed, the coolant circuit guides the
coolant circulating therein to the radiator and performs heat
transfer between the coolant and ambient air at the radiator.
5. The vehicle air-conditioning apparatus according to claim 2,
wherein the Peltier element includes a cooling portion that
performs a heat transfer with the coolant circulating in a coolant
circuit, and the coolant circuit cools an electric device mounted
on the vehicle by the coolant circulating therein.
6. The vehicle air-conditioning apparatus according to claim 5,
wherein the coolant circuit includes a heat exchanger that allows
the coolant circulating in the coolant circuit to flow in the heat
exchanger, thereby performing heat transfer between the coolant and
ambient air.
7. The vehicle air-conditioning apparatus according to claim 3,
comprising a control unit, wherein when the passenger compartment
is warmed in a case where the vehicle runs with the internal
combustion engine stopped, the controller switches the path for
circulating the coolant in the circulation circuit to the second
path and causes the heating portion of the Peltier element to be
heated, and when the passenger compartment is warmed in a case
where the vehicle runs with the internal combustion engine being
operated, the control unit switches the path for circulating the
coolant in the circulation circuit to the first path and stops the
heating operation of the heating portion of the Peltier element.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This is a national phase application based on the PCT
International Patent Application No. PCT/JP2011/055132 filed on
Mar. 4, 2011, the entire contents of which are incorporated herein
by reference.
FIELD OF THE DISCLOSURE
[0002] The present invention relates to a vehicle air-conditioning
apparatus.
BACKGROUND OF THE DISCLOSURE
[0003] In a vehicle having an internal combustion engine, such as
an automobile, the temperature in the passenger compartment is
adjusted by cooling air sent to the compartment by a cooling
device, or heating the air by use of heat of the internal
combustion engine. However, there are an increasing number of types
of vehicles in which it is difficult to utilize the internal
combustion engine as a heat source for air-conditioning
(temperature regulation) of the compartment. Such vehicles include
an electric vehicle that does not have the internal combustion
engine but only has a motor as a drive source, and a hybrid vehicle
that has a motor and an internal combustion engine as drive
sources, and frequently stops the internal combustion engine.
[0004] From the circumstance described above, it is considered that
a Peltier element described in Patent Document 1 may be used for
air-conditioning of a passenger compartment, for example. A Peltier
element includes a cooling portion absorbing heat and a heating
portion discharging heat. The cooling portion and the heating
portion can be interchanged by inversing the polarity of an
electrode. When an air-conditioning apparatus is used to decrease
the temperature of the passenger compartment for cooling, air sent
into the passenger compartment is cooled by the cooling portion of
the Peltier element. On the other hand, when the air-conditioning
apparatus is used to increase the temperature of the passenger
compartment for warming, the polarity of the electrode on the
Peltier element is inversed from the polarity for cooling, whereby
the air sent into the passenger compartment is heated by the
heating portion of the Peltier element.
PRIOR ART DOCUMENT
Patent Document
[0005] Patent Document 1
[0006] Japanese Laid-Open Patent Publication No. 10-35268
(paragraphs [0012] to [0014], FIG. 1)
SUMMARY OF THE INVENTION
Problems that the Invention is to Solve
[0007] When a Peltier element is used for air-conditioning of the
passenger compartment as described above, the air-conditioning
(warming) of the passenger compartment is possible even in a
vehicle in which it is difficult to utilize the internal combustion
as a heat source for air-conditioning of the passenger
compartment.
[0008] However, to obtain the structure of an air-conditioning
apparatus using a Peltier element, significant changes must be made
to the structure of a conventional air-conditioning apparatus that
cools air sent to a passenger compartment by a cooling device and
heats the air by utilizing heat of the internal combustion engine.
When the structure of the air-conditioning apparatus is
significantly changed, a conventional facility cannot be used for
producing the apparatus. Therefore, a facility for producing the
apparatus has to be remodeled. Since the facility for producing the
apparatus has to be remodeled, costs for producing the
air-conditioning apparatus are increased.
[0009] It has therefore been desired that air-conditioning of a
passenger compartment be done (the passenger compartment be warmed)
in a vehicle in which it is difficult to use an internal combustion
engine as a heat source for the air-conditioning of the passenger
compartment, while utilizing a conventional air-conditioning
apparatus that cools air sent to the passenger compartment by a
cooling device and heats the air by utilizing the heat of the
internal combustion engine.
[0010] Accordingly, it is an objective of the present invention to
provide a vehicle air-conditioning apparatus that performs
air-conditioning of a passenger compartment without entailing a
significant change in the structure in a vehicle in which it is
difficult to use an internal combustion engine as a heat source for
the air-conditioning of the passenger compartment.
Means for Solving the Problems
[0011] In order to achieve the foregoing object, in a vehicle
air-conditioning apparatus according to the present invention, upon
cooling or heating air sent to the passenger compartment for
adjusting a temperature in the passenger compartment, the air is
cooled by a cooling device, and the air is heated by a Peltier
element. One mounted in a conventional air-conditioning apparatus
can be used as the cooling device. Therefore, the significant
change in the structure of the air-conditioning apparatus is
avoided. Even in a vehicle in which it is difficult to use the
internal combustion engine as a heat source for the
air-conditioning of the passenger compartment, air sent to the
passenger compartment can be heated by a Peltier element.
Therefore, the air-conditioning of the passenger compartment can be
done (the passenger compartment can be warmed). Accordingly, an
air-conditioning of the passenger compartment can be done without
entailing a significant change in the structure in a vehicle in
which it is difficult to use the internal combustion engine as a
heat source for the air-conditioning of the passenger
compartment.
[0012] The conventional air-conditioning apparatus includes a
circulation circuit for circulating coolant performing heat
transfer with an internal combustion engine mounted on a vehicle,
and air sent to the passenger compartment is heated by the coolant.
Therefore, a vehicle having an internal combustion engine can
employ a method for heating the coolant in the circulation circuit
by the heating portion of a Peltier element and heating the air
sent to the passenger compartment through the heated coolant, as a
method for heating the air by the Peltier element. In this case,
the air sent to the passenger compartment can be heated by the
Peltier element by utilizing the circulation circuit mounted in the
conventional air-conditioning apparatus. Accordingly, the
significant change in the structure of the air-conditioning
apparatus from the conventional structure can be avoided. When the
internal combustion engine is operated to generate heat, this heat
can be collected by the coolant circulating in the circulation
circuit, and can be utilized for the air-conditioning of the
passenger compartment (for warming the passenger compartment).
[0013] In accordance with one aspect of the present invention, the
circulation circuit includes a first path that allows the coolant
circulating in the circulation circuit to pass through the internal
combustion engine and a second path that allows the coolant to
bypass the internal combustion engine. Either one of the first path
and the second path is used as a path for circulating the coolant.
In accordance with one aspect of the present invention, the
circulation circuit includes a first path that allows the coolant
circulating in the circulation circuit to pass through the internal
combustion engine and a second path that allows the coolant to
bypass the internal combustion engine. Either one of the first path
and the second path is used as a path for circulating the coolant.
In this case, the second path can be selected as the path for
circulating the coolant in the circulation circuit, when the
internal combustion engine generates a small amount of heat. On the
other hand, the first path can be selected when the internal
combustion engine generates a large amount of heat. If the second
path is selected as the path for circulating the coolant in the
circulation circuit as described above when the internal combustion
engine generates a small amount of heat, the heat of the coolant
heated by the heating portion of the Peltier element cannot be
drawn by the internal combustion engine. Therefore, the coolant is
effectively heated by the heating portion of the Peltier element.
If the first path is selected as the path for circulating the
coolant in the circulation circuit as described above when the
internal combustion engine generates a large amount of heat, the
coolant can be heated by the heating portion of the Peltier
element. Therefore, the application of heat to the coolant by the
heating portion of the Peltier element can be stopped, or the
amount of heat for heating the coolant can be reduced.
[0014] In accordance with another aspect of the present invention,
the circulation circuit includes a radiator. When the temperature
of the coolant circulating in the circulation circuit is greater
than or equal to a predetermined determination value, the radiator
allows to flow therein to perform heat transfer between the coolant
and ambient air. The Peltier element includes a cooling portion
that performs heat transfer with the coolant circulating in a
coolant circuit. The coolant circuit guides the coolant circulating
therein to the radiator and performs heat transfer between the
coolant and ambient air at the radiator. In accordance with one
aspect of the present invention, the circulation circuit includes a
radiator. When the temperature of the coolant circulating in the
circulation circuit is greater than or equal to a predetermined
determination value, the radiator allows coolant to flow therein to
perform heat transfer between the coolant and ambient air. The
Peltier element includes a cooling portion that performs heat
transfer with the coolant circulating in a coolant circuit. The
coolant circuit guides the coolant circulating therein to the
radiator and performs heat transfer between the coolant and ambient
air at the radiator. The heat transfer described above prevents an
excessive temperature drop of the coolant in the coolant circuit.
Therefore, an excessive temperature drop of the cooling portion of
the Peltier element performing the heat transfer with the coolant
is also prevented. When the heating portion performs the heating
operation, heat is transferred from the cooling portion to the
heating portion of the Peltier element. Therefore, in the Peltier
element, the heat is more efficiently transferred from the cooling
portion to the heating portion; in other words, the coolant is more
efficiently heated by the heating portion as the temperature
difference between the cooling portion and the heating portion
becomes smaller. Since a temperature drop of the cooling portion of
the Peltier element is prevented as described above, the
temperature difference between the heating portion and the cooling
portion of the Peltier element is reduced, and the heating portion
of the Peltier element efficiently heats the coolant.
[0015] In accordance with one aspect of the present invention, the
Peltier element includes a cooling portion that performs heat
transfer with the coolant circulating in the coolant circuit for
cooling an electric device mounted on a vehicle. When the heating
portion performs heating operation, heat is transferred from the
cooling portion to the heating portion of the Peltier element.
Therefore, the temperature of the cooling portion decreases. When
the coolant having the decreased temperature due to the heat
transfer between the cooling portion of the Peltier element and the
coolant in the coolant circuit is used for cooling the electric
device, the electric device is effectively cooled. Since the
coolant receives heat from the electric device, an excessive
temperature drop of the coolant in the coolant circuit is
prevented. Therefore, an excessive temperature drop of the cooling
portion of the Peltier element is also prevented. In the Peltier
element, the heat is more efficiently transferred from the cooling
portion to the heating portion. In other words, the coolant is more
efficiently heated by the heating portion as the temperature
difference between the cooling portion and the heating portion
becomes smaller. Accordingly, when a temperature drop of the
cooling portion of the Peltier element is prevented as described
above, the temperature difference between the heating portion and
the cooling portion of the Peltier element is reduced. As a result,
the heating operation by the heating portion of the Peltier element
is efficiently performed.
[0016] In accordance with one aspect of the present invention, the
coolant circuit includes a heat exchanger that allows the coolant
circulating in the coolant circuit to flow therein for performing
heat transfer between the coolant and ambient air. This structure
prevents an excessive temperature drop of the coolant due to the
heat transfer between the coolant and ambient air by the heat
exchanger in the coolant circuit, when a temperature drop of the
coolant cannot be prevented only by the heat from the electric
device under the condition in which the coolant in the coolant
circuit is cooled by the cooling portion of the Peltier element.
Accordingly, an excessive temperature drop of the cooling portion
of the Peltier element, which performs heat transfer with the
coolant, is also prevented. When a temperature drop of the cooling
portion of the Peltier element is prevented as described above, the
temperature difference between the heating portion and the cooling
portion of the Peltier element is reduced. As a result, the heating
operation by the heating portion of the Peltier element is
efficiently performed.
[0017] In accordance with one aspect of the present invention, the
vehicle air-conditioning apparatus includes a control unit that
switches the path for circulating the coolant in the circulation
circuit to the second path, and allows the heating portion of the
Peltier element to perform heating operation, when the passenger
compartment is warmed during when the vehicle runs with the
internal combustion engine being stopped. When the passenger
compartment is warmed during when the vehicle runs with the
internal combustion engine being operated, the control unit
switches the path for circulating the coolant in the circulation
circuit to the first path, and stops the heating operation by the
heating portion of the Peltier element. If the second path is
selected as described above as the path for circulating the coolant
in the circulation circuit when the passenger compartment is warmed
during when the vehicle runs with the internal combustion engine
being stopped, the heat of the coolant heated by the heating
portion of the Peltier element is not removed by the internal
combustion engine. Accordingly, the coolant is effectively heated
by the heating portion of the Peltier element. If the first path is
selected as described above as the path for circulating the coolant
in the circulation circuit when the passenger compartment is warmed
during when the vehicle runs with the internal combustion engine
being operated, the coolant is heated by the internal combustion
engine, although the coolant is not heated by the heating portion
of the Peltier element. Accordingly, the heating operation of the
heating portion of the Peltier element is stopped, and unnecessary
operation of the Peltier element is avoided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a schematic diagram illustrating an entire
air-conditioning apparatus according to a first embodiment;
[0019] FIG. 2 is a schematic diagram illustrating a first mode in
the air-conditioning apparatus of the first embodiment;
[0020] FIG. 3 is a schematic diagram illustrating a second mode in
the air-conditioning apparatus of the first embodiment;
[0021] FIG. 4 is a schematic diagram illustrating a third mode in
the air-conditioning apparatus of the first embodiment;
[0022] FIG. 5 is a schematic diagram illustrating a fourth mode in
the air-conditioning apparatus of the first embodiment;
[0023] FIG. 6 is a schematic diagram illustrating a fifth mode in
the air-conditioning apparatus of the first embodiment;
[0024] FIG. 7 is a flowchart illustrating a procedure of an
air-conditioning of a passenger compartment;
[0025] FIG. 8 is a schematic diagram illustrating an entire
air-conditioning apparatus according to a second embodiment;
[0026] FIG. 9 is a schematic diagram illustrating a first mode in
the air-conditioning apparatus of the second embodiment;
[0027] FIG. 10 is a schematic diagram illustrating a second mode in
the air-conditioning apparatus of the second embodiment;
[0028] FIG. 11 is a schematic diagram illustrating a third mode in
the air-conditioning apparatus of the second embodiment;
[0029] FIG. 12 is a schematic diagram illustrating a fourth mode in
the air-conditioning apparatus of the second embodiment; and
[0030] FIG. 13 is a schematic diagram illustrating a fifth mode in
the air-conditioning apparatus of the second embodiment.
MODES FOR CARRYING OUT THE INVENTION
First Embodiment
[0031] An air-conditioning apparatus for a hybrid vehicle according
to a first embodiment of the present invention will now be
described with reference to FIGS. 1 to 7.
[0032] The hybrid vehicle includes, as drive sources, a motor
generator and an internal combustion engine, and switches the drive
source to be used according to a driving condition or driving
requirement. More specifically, the hybrid vehicle uses only the
motor generator as the drive source, uses only the internal
combustion engine as the drive source, or uses both the internal
combustion engine and the motor generator as the drive source.
[0033] The air-conditioning apparatus for the hybrid vehicle
described above is provided with a cooling device 2 cooling air
sent to a passenger compartment 1 as illustrated in FIG. 1. The
cooling device 2 is a vapor compression heat pump. The cooling
device 2 includes a compressor 3 compressing refrigerant, a
condenser 4 that cools the refrigerant, which has been compressed
and heated by the compressor 3, by ambient air, an expansion valve
5 that expands the refrigerant cooled by the condenser 4, and an
evaporator 6 that performs heat transfer between the refrigerant,
which has been expanded and cooled by the expansion valve 5, and
the air sent to the passenger compartment 1. With this structure,
in the air-conditioning apparatus described above, when the
compressor 3 in the cooling device 2 is driven to circulate the
refrigerant, the low-temperature refrigerant passes through the
evaporator 6 to cool the air sent to the passenger compartment 1 by
the refrigerant.
[0034] The air-conditioning apparatus is provided with a
circulation circuit 8, which circulates coolant performing heat
transfer with the internal combustion engine 7, and heats the air
sent to the passenger compartment 1 by the coolant. The circulation
circuit 8 includes an electric pump 9 for circulating the coolant
in the circulation circuit 8, and a heater core 10 that performs
heat transfer between the coolant in the circulation circuit 8 and
the air sent to the passenger compartment 1 in order to heat the
air by the coolant. The circulation circuit 8 also includes a first
path 8a that forms the passage of the coolant, circulating in the
circulation circuit, in the internal combustion engine 7, a second
path 8b that forms a bypass of the coolant from the internal
combustion engine 7, and a changeover valve 11 that changes the
path for circulating the coolant in the circulation circuit 8 to
the first path 8a or to the second path 8b. With the switching
operation of the changeover valve 11, either one of the first path
8a and the second path 8b is used as a path for circulating the
coolant in the circulation circuit 8. When the internal combustion
engine 7 generates heat during when the coolant circulates in the
circulation circuit 8 through the first path 8a, the coolant
receives heat from the internal combustion engine 7, so that the
temperature of the coolant increases.
[0035] The first path 8a includes a radiator 12 that performs heat
transfer between the coolant and ambient air, and a thermostat 13
that inhibits or allows the passage of the coolant in the radiator
12 based upon the temperature of the coolant in the first path 8a.
The thermostat 13 inhibits the passage of the coolant through the
radiator 12 when the temperature of the first path 8a is less than
a determination value set beforehand. On the other hand, the
thermostat 13 allows the passage of the coolant through the
radiator 12 when the temperature of the coolant is higher than or
equal to the determination value. Accordingly, when the temperature
of the coolant is higher than or equal to the determination value
during the circulation in the circulation circuit 8 through the
first path 8a, the coolant is caused to flow into the radiator 12.
The heat transfer between the coolant and ambient air is done in
the radiator 12, whereby the coolant is cooled. Thus, an excessive
temperature rise of the coolant is prevented.
[0036] The circulation circuit 8 is provided with a passage 14
connecting an upstream side and a downstream side of the heater
core 10, and a shutoff valve 15 that can shut the circulation
through the heater core 10 from the circulation circuit 8. The
shutoff valve 15 makes the switching operation in order to allow
the coolant to selectively flow through the heater core 10 or the
passage 14. When the coolant is caused to flow into the passage 14
by the switching operation of the shutoff valve 15, the coolant
does not flow into the heater core 10. Therefore, the heater core
10 is in the state of being shut off from the circulation circuit 8
for the circulation of the coolant. On the other hand, when the
switching operation of the shutoff valve 15 is done in order to
inhibit the circulation of the coolant in the passage 14, the
coolant is caused to flow into the heater core 10. Therefore, the
shutoff state of the heater core 10 to the circulation circuit 8 is
canceled. Accordingly, when the temperature of the coolant
circulating in the circulation circuit 8 is high, the shutoff state
of the heater core 10 to the circulation circuit 8 is canceled to
cause the coolant to flow into the heater core 10. Thus, the air
sent to the passenger compartment 1 is heated by the coolant.
[0037] The temperature regulation in the passenger compartment 1 by
the air-conditioning apparatus is realized by cooling the air sent
to the passenger compartment 1 by the evaporator 6 of the cooling
device 2, or by heating the air by the heater core 10 in the
circulation circuit 8. The temperature of the coolant passing
through the heater core 10 in the circulation circuit 8 increases
in receipt of the heat from the internal combustion engine 7.
Therefore, the air sent to the compartment 1 is heated by utilizing
the heat from the internal combustion engine 7. However, in the
hybrid vehicle, the operation of the internal combustion engine 7
frequently stops during the driving by use of the motor generator.
Under this condition, it is difficult to use the internal
combustion engine 7 as the heat source for adjusting the
temperature (for the air-conditioning) of the passenger compartment
1. Accordingly, the air-conditioning apparatus is provided with a
Peltier element 16 for heating the coolant in the circulation
circuit 8 in order that the air sent to the passenger compartment 1
is heated even under the condition in which the internal combustion
engine 7 is difficult to be used as the heat source for adjusting
the temperature in the passenger compartment 1.
[0038] The Peltier element 16 includes a heating portion 16a for
radiating heat and a cooling portion 16b for absorbing heat. The
coolant circulating in the circulation circuit 8 is heated by the
heating portion 16a. When the heating portion 16a of the Peltier
element 16 heats the coolant, heat is transferred to the heating
portion 16a from the cooling portion 16b. Therefore, in the Peltier
element 16, the heat is more efficiently transferred from the
cooling portion 16b to the heating portion 16a, in other words, the
coolant is more efficiently heated by the heating portion 16a as
the temperature difference between the cooling portion 16b and the
heating portion 16a becomes smaller. The coolant heated by the
heating portion 16a of the Peltier element 16 heats the air sent to
the passenger compartment 1 when passing through the heater core
10. Accordingly, the Peltier element 16 is capable of heating the
air sent to the passenger compartment 1 via the coolant, since the
heating portion 16a heats the coolant in the circulation circuit
8.
[0039] The air-conditioning apparatus is provided with a coolant
circuit 17 that circulates the coolant performing heat transfer
with the cooling portion 16b of the Peltier element 16. The coolant
circuit 17 guides the coolant circulating therein to the radiator
12 of the circulation circuit 8 (the first path 8a) to perform the
heat transfer between the coolant and the ambient air by the
radiator 12. The coolant circuit 17 shares the portion of the first
path 8a from the upstream side to the downstream side of the
radiator 12 with the circulation circuit 8. The coolant circuit 17
is provided with an electric pump 18 for circulating the coolant in
the circuit 17. The coolant circuit 17 is also provided with a
control valve 19 that inhibits and allows passage of coolant
between the portion corresponding to the cooling portion 16b of the
Peltier element 16 and the portion shared by the first path 8a. The
flow of the coolant is inhibited by closing the control valve 19,
while it is allowed by opening the control valve 19.
[0040] When the coolant in the coolant circuit 17 is cooled by the
cooling portion 16b of the Peltier element 16, the coolant is
guided to the radiator 12 of the circulation circuit 8 (the first
path 8a) by opening the control valve 19 and driving the pump 18 to
perform the heat transfer between the coolant and the ambient air.
This process prevents an excessive temperature drop of the coolant
in the coolant circuit 17. Therefore, an excessive temperature drop
of the cooling portion 16b of the Peltier element 16, which
performs the heat transfer with the coolant in the coolant circuit
17, is also prevented. As described above, in the Peltier element
16, heat is more efficiently transferred from the cooling portion
16b to the heating portion 16a, in other words, the coolant in the
circulation circuit 8 is more efficiently heated by the heating
portion 16a as the temperature difference between the cooling
portion 16b and the heating portion 16a becomes smaller. Since a
temperature drop of the cooling portion 16b of the Peltier element
16 is prevented, the temperature difference between the heating
portion 16a and the cooling portion 16b of the Peltier element 16
is reduced, whereby the heating portion 16a of the Peltier element
16 can efficiently heat the coolant in the circulation circuit
8.
[0041] The air-conditioning apparatus has an electronic control
device 20 mounted on the hybrid vehicle for controlling various
operations of the motor generator and the internal combustion
engine 7. The electronic control device 20 controls to drive
various devices in the air-conditioning apparatus, i.e., controls
to drive the compressor 3, the pump 9, the changeover valve 11, the
shutoff valve 15, the Peltier element 16, the pump 18, and the
control valve 19. The air-conditioning (the temperature regulation)
of the passenger compartment 1 in the hybrid vehicle is done
through the control of various devices in the air-conditioning
apparatus by the electronic control device 20. In the hybrid
vehicle described above, an operation mode of the air-conditioning
apparatus is switched to one of first to fifth modes for the
air-conditioning of the passenger compartment 1. The first to fifth
modes of the air-conditioning apparatus for the air-conditioning of
the passenger compartment 1 will individually be described
below.
[First Mode]
[0042] This mode is used to warm the passenger compartment 1 when
the hybrid vehicle runs only with the motor generator, in other
words, when the hybrid vehicle runs with the internal combustion
engine 7 being stopped. When the hybrid vehicle runs only with the
motor generator, the heat generated from the internal combustion
engine 7 is small. Therefore, it is difficult to use the internal
combustion engine 7 as the heat source for warming the passenger
compartment 1 (for increasing the temperature in the passenger
compartment 1). In order to warm the passenger compartment 1 by
heating the air sent to the passenger compartment 1 in the first
mode, the air is heated by the Peltier element 16.
[0043] Specifically, as illustrated in FIG. 2, the pump 9 in the
circulation circuit 8 is driven to circulate the coolant in the
circulation circuit 8, and the changeover valve 11 is operated in
order that the second path 8b is used as the path for circulating
the coolant. The shutoff state of the heater core 10 to the
circulation circuit 8 is canceled through the operation of the
shutoff valve 15, and the Peltier element 16 is driven to heat the
coolant circulating in the circulation circuit 8 by the heating
portion 16a of the Peltier element 16. Thus, the coolant heated by
the Peltier element 16 to have an increased temperature is caused
to flow through the heater core 10. As a result, the air sent to
the compartment 1 is heated by the coolant, and the passenger
compartment 1 is warmed by the heated air sent to the passenger
compartment 1.
[0044] When the coolant in the circulation circuit 8 is heated by
the heating portion 16a of the Peltier element 16 by the drive of
the Peltier element 16, the heat is transferred from the cooling
portion 16b to the heating portion 16a of the Peltier element 16,
so that the temperature of the cooling portion 16b drops. In order
to prevent an excessive temperature drop of the cooling portion
16b, the control valve 19 in the coolant circuit 17 is opened to
allow the flow of the coolant between the portion of the coolant
circuit 17 corresponding to the cooling portion 16b of the Peltier
element 16 and the shared portion by the first path 8a, and the
pump 18 is driven. With this process, the coolant in the coolant
circuit 17 is circulated.
[0045] When the coolant in the coolant circuit 17 is circulated, an
excessive temperature drop of the coolant is prevented due to the
heat transfer between the coolant and the ambient air during the
passage of the coolant through the radiator 12, although the
coolant is cooled by the cooling portion 16b of the Peltier element
16. Since heat is exchanged between the coolant of which the
temperature drop is suppressed as described above and the cooling
portion 16b of the Peltier element 16, an excessive temperature
drop of the cooling portion 16b is prevented. Accordingly, the
increase in the temperature difference between the heating portion
16a and the cooling portion 16b of the Peltier element 16 due to a
temperature drop of the cooling portion 16b is prevented.
Therefore, the coolant in the circulation circuit 8 is efficiently
heated by the Peltier element 16.
[0046] In the first mode, the compressor 3 in the cooling device 2
is stopped. Therefore, the air sent to the passenger compartment 1
is not cooled by the cooling device 2.
[Second Mode]
[0047] This mode is used to warm the passenger compartment 1 when
the hybrid vehicle runs by using both the motor generator and the
internal combustion engine 7, or when the hybrid vehicle runs only
with the internal combustion engine 7, i.e., when the hybrid
vehicle runs with the internal combustion engine 7 being operated.
Under the condition described above, heat from the internal
combustion engine 7 increases. Therefore, the internal combustion
engine 7 can be utilized as the heat source for warming the
passenger compartment 1 (for increasing the temperature in the
passenger compartment 1). In order to warm the passenger
compartment 1 by heating the air sent to the passenger compartment
1 in the first mode, the air is heated by utilizing the heat from
the internal combustion engine 7.
[0048] Specifically, as illustrated in FIG. 3, the pump 9 in the
circulation circuit 8 is driven to circulate the coolant in the
circulation circuit 8, and the changeover valve 11 is operated in
order that the first path 8a is used as the path for circulating
the coolant. The shutoff state of the heater core 10 to the
circulation circuit 8 is canceled through the operation of the
shutoff valve 15. Thus, the coolant of which the temperature is
increased by the heat from the internal combustion engine 7 flows
through the heater core 10. As a result, the air sent to the
passenger compartment 1 is heated by the coolant, and the passenger
compartment 1 is warmed by the heated air sent to the passenger
compartment 1.
[0049] When the temperature of the coolant passing through the
first path 8a is higher than or equal to the determination value
due to the temperature rise of the coolant circulating in the
circulation circuit 8 by the heat from the internal combustion
engine 7, the thermostat 13 allows the passage of the coolant
through the radiator 12. As a result, the coolant circulating in
the circulation circuit 8 flows through the radiator 12. Since the
coolant flowing through the radiator 12 is cooled by the ambient
air, an excessive temperature rise of the coolant circulating in
the circulation circuit 8 is prevented.
[0050] In the second mode, the Peltier element 16 is deactivated.
Therefore, the coolant circulating in the circulation circuit 8 is
not heated by the heating portion 16a of the Peltier element 16.
Even in the second mode, the compressor 3 in the cooling device 2
is stopped. Therefore, the air sent to the passenger compartment 1
is not cooled by the cooling device 2.
[Third Mode]
[0051] This mode is used for cooling the passenger compartment 1.
Specifically, as illustrated in FIG. 4, the compressor 3 of the
cooling device 2 is driven to circulate the refrigerant in the
cooling device 2. With this, the low-temperature refrigerant passes
through the evaporator 6, so that the air sent to the passenger
compartment 1 is cooled by the refrigerant. The passenger
compartment 1 is cooled by sending the air cooled as described
above to the passenger compartment 1.
[0052] In the third mode, the air sent to the passenger compartment
1 is not heated. Therefore, it is unnecessary to heat the coolant
in the circulation circuit 8 by the Peltier element 16.
Accordingly, the Peltier element 16 is deactivated. When the hybrid
vehicle runs only with the motor generator, the operation of the
pump 9 in the circulation circuit 8 is stopped, so that the
circulation of the coolant in the circuit 8 is discontinued.
[0053] On the other hand, when the hybrid vehicle runs by using
both the motor generator and the internal combustion engine 7, or
when the hybrid vehicle runs only with the internal combustion
engine 7, the internal combustion engine 7 has to be cooled in
order to prevent an excessive temperature rise of the internal
combustion engine 7. Therefore, the pump 9 in the circulation
circuit 8 is driven to circulate the coolant in the circulation
circuit 8, and the changeover valve 11 is changed in order that the
first path 8a is used as the path for circulating the coolant. In
this case, the heater core 10 is in the shutoff state to the
circulation circuit 8 through the changeover operation of the
shutoff valve 15 in order not to allow the high-temperature coolant
circulating in the circulation circuit 8 to flow through the heater
core 10.
[Fourth Mode]
[0054] This mode is used to dehumidify and warm the passenger
compartment 1, when the hybrid vehicle runs only with the motor
generator, in other words, when the hybrid vehicle runs with the
internal combustion engine 7 being stopped. Specifically, as
illustrated in FIG. 5, the air sent to the passenger compartment 1
is heated as in the first mode (FIG. 2), and the air sent to the
passenger compartment 1 is cooled as in the third mode (FIG. 4). As
a result, the air sent to the passenger compartment 1 is heated by
the heater core 10, and with this state, dehumidified by the
evaporator 6. With this process, the temperature of the air
increases, and the moisture in the air is reduced. The passenger
compartment 1 is dehumidified and warmed by sending the air
described above to the passenger compartment 1.
[Fifth Mode]
[0055] This mode is used to dehumidify and warm the passenger
compartment 1 when the hybrid vehicle runs by using both the motor
generator and the internal combustion engine 7, or when the hybrid
vehicle runs only with the internal combustion engine 7, i.e., when
the hybrid vehicle runs with the internal combustion engine 7 being
operated. Specifically, as illustrated in FIG. 6, the air sent to
the passenger compartment 1 is heated as in the second mode (FIG.
3), and the air sent to the passenger compartment 1 is cooled as in
the third mode (FIG. 4). Thus, the passenger compartment 1 is
dehumidified and warmed as in the fourth mode.
[0056] A procedure of the air-conditioning (the temperature
regulation) of the passenger compartment 1 will now be described
with reference to a flowchart in FIG. 7 indicating an
air-conditioning routine. The air-conditioning routine is
periodically executed by an interrupt at an interval of a
predetermined time through the electronic control device 20, for
example.
[0057] In this routine, the operation mode of the air-conditioning
apparatus is changed to one of the first to fifth modes based upon
various requests, such as a request for cooling the passenger
compartment 1, a request for warming the passenger compartment 1,
and a request for dehumidifying the passenger compartment 1.
Whether the request for cooling or warming the passenger
compartment 1 is issued or not can be determined based upon the
actual temperature in the passenger compartment 1, and a target
temperature in the passenger compartment set by an occupant.
Whether the request for dehumidifying the passenger compartment 1
is issued or not can be determined according to the operation
position of a switch related to dehumidification operated by the
occupant.
[0058] In the air-conditioning routine, when the request for
cooling the passenger compartment 1 is has been made (S101: False),
the air-conditioning apparatus is operated in the third mode to
cool the passenger compartment 1 (S110).
[0059] On the other hand, when it is determined that a request for
cooling the passenger compartment 1 has not been made in S101, it
is determined whether the request for warming the passenger
compartment 1 has been made or not (S102). When the determination
is positive, it is determined whether the hybrid vehicle is running
only with the motor generator, i.e., whether or not it is difficult
to warm the passenger compartment 1 by utilizing the heat from the
internal combustion engine 7 (S103). When the determination in S103
is positive, it is determined whether the request for dehumidifying
the passenger compartment 1 has been made or not (S104). When the
determination in S104 is true, the air-conditioning apparatus is
operated in the first mode to warm the passenger compartment 1
(S105). When the determination in S104 is false, the
air-conditioning apparatus is operated in the fourth mode to
dehumidify and warm the passenger compartment 1 (S106). When the
air-conditioning apparatus is operated in the first mode or in the
fourth mode, the electronic control device 20 and the changeover
valve 11 function as a control unit for changing the path for
circulating the coolant in the circulation circuit 8 to the second
path 8b, and for allowing the heating portion 16a of the Peltier
element 16 to perform the heating operation.
[0060] When the determination in S103 is negative, i.e., when it is
determined that the hybrid vehicle is not running with only the
motor generator, but is running by using both the motor generator
and the internal combustion engine 7, or by using only the internal
combustion engine 7, it is then determined whether a request for
dehumidifying the passenger compartment 1 has been made or not
(S107). When the determination in S107 is true, the
air-conditioning apparatus is operated in the second mode to warm
the passenger compartment 1 (S108). When the determination in S107
is false, the air-conditioning apparatus is operated in the fifth
mode to dehumidify and warm the passenger compartment 1 (S109).
When the air-conditioning apparatus is operated in the second mode
or in the fifth mode, the electronic control device 20 and the
changeover valve 11 function as a control unit for changing the
path for circulating the coolant in the circulation circuit 8 to
the first path 8a, and for allowing the heating portion 16a of the
Peltier element 16 to perform the heating operation.
[0061] As described above, the present embodiment achieves the
following advantages.
[0062] (1) When the air sent to the passenger compartment 1 is
cooled for the temperature regulation (air-conditioning) of the
passenger compartment 1, the air is cooled by the cooling device 2,
which is a vapor compression heat pump. When the air sent to the
passenger compartment 1 is heated for the temperature regulation
(air-conditioning) of the passenger compartment 1, the air can be
heated by utilizing the heat from the internal combustion engine 7,
or by using the Peltier element 16. Since a cooling device mounted
in a conventional air-conditioning apparatus can be used as the
cooling device 2, the significant change in the structure of the
air-conditioning apparatus is avoided. Even under the condition in
which the internal combustion engine 7 is difficult to be used as
the heat source for the air-conditioning of the passenger
compartment 1, such as the case where the hybrid vehicle runs by
using only the motor generator, the air-conditioning of the
passenger compartment can be done (the passenger compartment can be
warmed), since the air sent to the passenger compartment 1 can be
heated by the Peltier element 16. Accordingly, the air-conditioning
of the passenger compartment can be realized without a significant
change in the structure in the vehicle in which it is difficult to
use the internal combustion engine 7 as the heat source for the
air-conditioning of the passenger compartment.
[0063] (2) The formation of the circulation circuit (corresponding
to the circulation circuit 8 in the present embodiment) for
circulating the coolant performing heat transfer with the internal
combustion engine 7, and the application of heat by the coolant in
the circulation circuit to the air sent to the passenger
compartment 1 have been done in conventional air-conditioning
apparatuses. In the air-conditioning apparatus according to the
present embodiment, the coolant in the circulation circuit 8 is
heated by the heating portion 16a of the Peltier element 16.
Therefore, the air sent to the passenger compartment 1 is heated by
the heating portion 16a of the Peltier element 16 via the coolant.
In this case, the air sent to the passenger compartment 1 can be
heated by the Peltier element 16 by utilizing the circulation
circuit provided in the conventional air-conditioning apparatus.
Accordingly, a significant change in the structure of the
air-conditioning apparatus from the conventional one is avoided.
When the internal combustion engine 7 generates heat because the
hybrid vehicle is running by using both the motor generator and the
internal combustion engine 7, or by using only the internal
combustion engine 7, the heat can be collected by the coolant
circulating in the circulation circuit 8, and can be utilized for
the air-conditioning of the passenger compartment 1 (for warming
the passenger compartment 1).
[0064] (3) The circulation circuit 8 includes the first path 8a,
which allows the coolant in the circuit to pass through the
internal combustion engine 7, and the second path 8b, which allows
the coolant to bypass the internal combustion engine 7. Either one
of the first path 8a and the second path 8b is used as the path for
circulating the coolant. In this case, the second path 8b can be
selected as the path for circulating the coolant in the circulation
circuit 8, when the heat generated by the internal combustion
engine 7 is small. On the other hand, the first path 8a can be
selected when the heat generated from the internal combustion
engine 7 is large.
[0065] Specifically, when the passenger compartment 1 is warmed in
the case where the hybrid vehicle runs with the internal combustion
engine 7 being stopped (with a small amount of heat from the
internal combustion engine 7), the path for circulating the coolant
in the circulation circuit 8 is changed to the second path 8b by
the electronic control device 20 and the changeover valve 11. In
addition, in this case, the heating portion 16a of the Peltier
element 16 is heated, and the coolant in the circulation circuit 8
is heated by the heating portion 16a. When the passenger
compartment 1 is warmed in the case where the hybrid vehicle is
running with the internal combustion engine 7 being operated (with
a large amount of heat from the internal combustion engine 7), the
path for circulating the coolant in the circulation circuit 8 is
changed to the first path 8a by the electronic control device 20
and the changeover valve 11. In addition, in this case, the heating
operation of the heating portion 16a of the Peltier element 16 is
stopped. Therefore, the process of heating the coolant in the
circulation circuit 8 by the heating portion 16a is stopped.
[0066] Since the second path 8b is selected as the path for
circulating the coolant in the circulation circuit 8 in the case
where the passenger compartment 1 is warmed during when the hybrid
vehicle is running with the internal combustion engine 7 being
stopped, the removal of the heat of the coolant, which is heated by
the heating portion 16a of the Peltier element 16, by the internal
combustion engine 7 is prevented. Accordingly, the coolant is
effectively heated by the heating portion 16a of the Peltier
element 16. Since the first path 8a is selected as the path for
circulating the coolant in the circulation circuit 8 in the case
where the passenger compartment 1 is warmed during when the hybrid
vehicle is running with the internal combustion engine 7 being
operated, the coolant can be heated by the internal combustion
engine 7, although it is not heated by the heating portion 16a of
the Peltier element 16. Accordingly, the heating operation of the
heating portion 16a of the Peltier element 16 can be stopped.
Therefore, the unnecessary operation of the Peltier element 16 is
avoided.
[0067] (4) The coolant circuit 17 allows the coolant, which
performs heat transfer with the cooling portion 16b of the Peltier
element 16, to circulate and guides the coolant to the radiator 12
in the circulation circuit 8 for performing the heat transfer
between the coolant and the ambient air by the radiator 12. The
heat transfer described above prevents an excessive temperature
drop of the coolant in the coolant circuit 17, and further,
prevents an excessive temperature drop of the cooling portion 16b
of the Peltier element 16, which performs heat transfer with the
coolant. In the Peltier element 16, the heat can be more
efficiently transferred from the cooling portion 16b to the heating
portion 16a, in other words, the coolant in the circulation circuit
8 can be more efficiently heated by the heating portion 16a as the
temperature difference between the cooling portion 16b and the
heating portion 16a becomes smaller. Since a temperature drop of
the cooling portion 16b of the Peltier element 16 is prevented as
described above, the temperature difference between the heating
portion 16a and the cooling portion 16b of the Peltier element 16
is reduced, whereby the heating portion of the Peltier element 16
can efficiently heat the coolant.
Second Embodiment
[0068] A second embodiment will now be described with reference to
FIGS. 8 to 13.
[0069] As illustrated in FIG. 8, a coolant circuit 17 in an
air-conditioning apparatus according to the present embodiment is
different from the one in the first embodiment. The coolant circuit
17 is provided independent of the circulation circuit 8. The
coolant circuit 17 cools various electric devices such as the motor
generator 21 and the electronic device 22 including the inverter.
The motor generator 21 functions as the drive source of the hybrid
vehicle, and it is controlled by the electronic control device 20.
The coolant circuit 17 includes a heat exchanger 23, which
transfers heat between the coolant circulating in the circuit and
the ambient air.
[0070] The different part from the first embodiment in the first to
fifth modes of the air-conditioning apparatus will be described.
The first to fifth modes of the air-conditioning apparatus are
illustrated in FIGS. 9 to 13. As understood from these drawings,
the coolant in the coolant circuit 17 is circulated by operating
the pump 18 in any of the first to fifth modes. Thus, various
electric devices such as the motor generator 21, and the electronic
device 22 including the inverter in the hybrid vehicle are cooled
by the coolant in the coolant circuit 17.
[0071] In the first mode (FIG. 9) and the fourth mode (FIG. 12),
heat is transferred from the cooling portion 16b to the heating
portion 16a, in other words, the coolant in the circulation circuit
8 is heated by the heating portion 16a, by operating the Peltier
element 16. In this case, the temperature decreases in the cooling
portion 16b of the Peltier element 16. The coolant having the
decreased temperature due to the heat transfer between the cooling
portion 16b and the coolant in the coolant circuit 17 is used to
cool the electric devices (the motor generator 21, the electronic
device 22). On the other hand, the coolant circulating in the
coolant circuit 17 receives heat from the electric devices, so that
an excessive temperature drop of the coolant is prevented.
[0072] The present embodiment achieves the advantages described
below.
[0073] (5) Even if the coolant in the coolant circuit 17 is cooled
by the cooling portion 16b due to a temperature drop of the cooling
portion 16b of the Peltier element 16 in the first mode and the
fourth mode of the air-conditioning apparatus, an excessive
temperature drop of the coolant is prevented, since the coolant
receives heat from the electric devices. Therefore, an excessive
temperature drop of the cooling portion 16b of the Peltier element
16, which performs the heat transfer with the coolant, is also
prevented. The temperature difference between the heating portion
16a and the cooling portion 16b of the Peltier element 16 is
reduced by the inhibition of a temperature drop of the cooling
portion 16b, whereby the coolant is efficiently heated by the
heating portion 16a of the Peltier element 16.
[0074] (6) When a temperature drop of the coolant in the coolant
circuit 17 cannot be prevented only by the heat from the electric
devices under the condition in which the coolant in the coolant
circuit 17 is cooled by the cooling portion 16b of the Peltier
element 16, an excessive temperature drop of the coolant is
prevented by the heat transfer between the coolant and the ambient
air in the heat exchanger 23 in the coolant circuit 17. Therefore,
an excessive temperature drop of the cooling portion 16b of the
Peltier element 16, which performs the heat transfer with the
coolant, is also prevented. Even in the case where a temperature
drop of the coolant in the coolant circuit 17 cannot be prevented
only by the heat from the electric devices, the temperature
difference between the heating portion 16a and the cooling portion
16b of the Peltier element 16 is reduced, whereby the coolant in
the circulation circuit 8 is efficiently heated by the heating
portion 16a of the Peltier element 16.
Other Embodiments
[0075] The respective embodiments described above may be modified
as described below.
[0076] In the first and second embodiments, the coolant in the
circulation circuit 8 may be supplementally heated by the Peltier
element 16 in the second mode or in the fifth mode.
[0077] In the first and second embodiments, the second path 8b and
the changeover valve 11 in the circulation circuit 8 may be removed
in order that the coolant circulating in the circulation circuit 8
always passes through the internal combustion engine 7.
[0078] In the first and second embodiments, the cooling portion 16b
of the Peltier element 16 does not always have to perform heat
transfer with the coolant in the coolant circuit 17.
[0079] In the first and second embodiments, the air sent to the
passenger compartment 1 may directly be heated by the heating
portion 16a of the Peltier element 16.
DESCRIPTION OF THE REFERENCE NUMERALS
[0080] 1 Passenger compartment
[0081] 2 Cooling device
[0082] 3 Compressor
[0083] 4 Condenser
[0084] 5 Expansion valve
[0085] 6 Evaporator
[0086] 7 Internal combustion engine
[0087] 8 Circulation circuit
[0088] 9 Pump
[0089] 10 Heater core
[0090] 8a First path
[0091] 8b Second path
[0092] 11 Changeover valve
[0093] 12 Radiator
[0094] 13 Thermostat
[0095] 14 Passage
[0096] 15 Shutoff valve
[0097] 16 Peltier element
[0098] 16a Heating portion
[0099] 16b Cooling portion
[0100] 17 Coolant circuit
[0101] 18 Pump
[0102] 19 Control valve
[0103] 20 Electronic control device
[0104] 21 Motor generator
[0105] 22 Electronic device
[0106] 23 Heat exchanger
* * * * *