THERMAL MANAGEMENT SYSTEM FOR VEHICLE

• US 20150101789A1
• Filed: 05/16/2013
• Published: 04/16/2015
• Est. Priority Date: 05/24/2012
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Kakehashi, Nobuharu, Nishikawa, Michio, Omi, Yasumitsu, Yamanaka, Takashi, Takeuchi, Masayuki, Enomoto, Norihiko
• Granted Patent: US 9,561,704 B2
• Time in Patent Office: Days
• US Class Current: 165/202
• CPC Class Codes: B60H 1/00278 for the battery arrangement of batteries B60R16/04
• CPC Class Codes: B60H 1/00485 Valves for air-conditioning devices, e.g. thermostatic valves valves per se F16K; thermostatic valves per se G05D23/02
• CPC Class Codes: B60H 1/00899 Controlling the flow of liquid in a heat pump system controlling the properties of the refrigerant liquid, e.g. pressure or temperature, B60H1/3204
• CPC Class Codes: B60H 1/039 from air leaving the interior of the vehicle, i.e. heat recovery
• CPC Class Codes: B60H 1/06 directly from main radiator
• CPC Class Codes: B60H 1/32284 comprising two or more secondary circuits, e.g. at evaporator and condenser side
• CPC Class Codes: B60H 2001/00307 Component temperature regulation using a liquid flow
• CPC Class Codes: B60H 2001/00928 comprising a secondary circuit
• CPC Class Codes: B60H 2001/00961 comprising means for defrosting outside heat exchangers
• CPC Class Codes: B60K 11/02 with liquid cooling
• CPC Class Codes: B60K 11/06 with air cooling
• CPC Class Codes: B60K 2001/003 with means for cooling the electrical propulsion units
• CPC Class Codes: B60K 2001/005 the electric storage means
• CPC Class Codes: B60K 2001/0416 Arrangement in the rear part of the vehicle
• CPC Class Codes: B60L 1/003 to auxiliary motors, e.g. for pumps, compressors
• CPC Class Codes: B60L 1/02 to electric heating circuits
• CPC Class Codes: B60L 2240/34 Cabin temperature
• CPC Class Codes: B60L 2240/36 Temperature of vehicle components or parts
• CPC Class Codes: B60L 2240/445 Temperature
• CPC Class Codes: B60L 2240/525 Temperature of converter or components thereof
• CPC Class Codes: B60L 2240/545 : Temperature
• CPC Class Codes: B60L 50/16 : with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/51 : characterised by AC-motors
• CPC Class Codes: B60L 53/14 : Conductive energy transfer
• CPC Class Codes: B60L 58/26 : by cooling
• CPC Class Codes: B60L 58/27 : by heating
• CPC Class Codes: F01P 2050/24 : Hybrid vehicles
• CPC Class Codes: F01P 2060/08 : Cabin heater
• CPC Class Codes: F01P 3/20 : Cooling circuits not specific to a single part of engine or machine F01P3/22 takes precedence
• CPC Class Codes: F01P 7/16 : by thermostatic control
• CPC Class Codes: F01P 7/165 : characterised by systems with two or more loops
• CPC Class Codes: H01M 10/625 : Vehicles
• CPC Class Codes: H01M 10/6561 : Gases
• CPC Class Codes: H01M 10/6563 : with forced flow, e.g. by blowers
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles

Abstract

First circulation portions switch a flow of a heat medium such that one of the heat media for two systems selectively circulates through a radiator flow path or a first bypass flow path. Second circulation portions switch the flow of the heat medium such that the heat media for the two systems selectively circulate with respect to a second flow path group. The first circulation portions and the second circulation portions are adapted to switch the flow of the heat medium so as to form a first circulation circuit for allowing the heat medium to circulate among a first flow path group, the second flow path group, and a first pump, as well as a second circulation circuit for allowing the heat medium to circulate among the first flow path group, the second flow path group, and a second pump.

Claims

1. A thermal management system for a vehicle, comprising:

a radiator exchanging heat between a heat medium and outside air;

a first flow path group including a radiator flow path in which the heat medium flows and the radiator is disposed, and a first bypass flow path and a second bypass flow path that allow the heat medium to bypass the radiator;

a cooler cooling the heat medium;

a heater heating the heat medium;

a heat medium circulation device through which the heat medium heated by the heater circulates;

a plurality of devices to be heat-exchanged that exchanges heat with the heat medium;

a second flow path group including (i) a cooler flow path in which the heat medium flows and the cooler is disposed, (ii) a heater flow path in which the heat medium flows and the heater is disposed, and a plurality of device flow paths in which the heat medium flows and the devices to be heat-exchanged are disposed;

a first pump and a second pump, sucking and discharging the heat medium in two systems;

a first circulation portion circulating heat medium in two systems, discharged from the first pump and the second pump, with respect to the first flow path group; and

a second circulation portion circulating the heat medium in the two systems, with respect to the second flow path group, wherein

the heat medium circulation device is disposed in the heater flow path, or the heater flow path is connected to an end of a flow path with the heat medium circulation device disposed therein,

the first circulation portion switches a flow of the heat medium such that one of the heat media for the two systems selectively circulates through the radiator flow path or the first bypass flow path,

the second circulation portion switches a flow of the heat medium such that the heat media for the two systems selectively circulate with respect to the second flow path group, and

the first circulation portion and the second circulation portion switch the flow of the heat medium so as to form a first circulation circuit that allows the heat medium to circulate between the second flow path group and the first pump, as well as a second circulation circuit that allows the heat medium to circulate among the first flow path group, the second flow path group, and the second pump.

2. The thermal management system for a vehicle according to claim 1, wherein

the heat medium circulation device is a heating heat exchanger that exchanges heat between the heat medium heated by the heater and air to be blown into a vehicle interior to heat the air.

3. The thermal management system for a vehicle according to claim 1, further comprising:

a second heat medium circulation circuit for circulation of a second heat medium; and

a heating heat exchanger that exchanges heat between the second heat medium and air to be blown into a vehicle interior so as to heat the air, wherein

a heat medium/heat medium heat exchanger of the heat medium circulation devices exchanges heat between the heat medium heated by the heater and the second heat medium.

4. The thermal management system for a vehicle according to claim 2, wherein

when the vehicle interior is heated with the air heated by the heating heat exchanger, the first circulation portion and the second circulation portion switch the flow of the heat medium, such that a device to be heat-exchanged among the devices to be heat-exchanged, in which a temperature of the heat medium at a heat medium outlet is a predetermined value or higher, the heating heat exchanger, and one bypass flow path of the first and second bypass flow paths are included in one circulation circuit of the first and second circulation circuits, and such that another device to be heat-exchanged among the devices to be heat-exchanged, in which a temperature of the heat medium at a heat medium outlet is less than the predetermined value, and one flow path of the first flow path group other than the one bypass flow path are included in the other circulation circuit of the first and second circulation circuits.

5. The thermal management system for a vehicle according to claim 3, wherein

when the vehicle interior is heated with the air heated by the heating heat exchanger, the first circulation portion and the second circulation portion switch the flow of the heat medium such that a device to be heat-exchanged among the devices to be heat-exchanged, in which a temperature of the heat medium at a heat medium outlet is a predetermined value or higher, the heat medium-heat medium heat exchanger, and one bypass flow path of the first and second bypass flow paths are included in one circulation circuit of the first and second circulation circuits, and such that another device to be heat-exchanged among the devices to be heat-exchanged, in which a temperature of the heat medium at a heat medium outlet is less than the predetermined value, and one flow path of the first flow path group other than the one bypass flow path are included in the other circulation circuit of the first and second circulation circuits.

6. The thermal management system for a vehicle according to claim 2, wherein

the cooler is a low-pressure side heat exchanger of a refrigeration cycle, and

the heater is a high-pressure side heat exchanger of the refrigeration cycle, wherein

when a total of an amount of heat dissipation into the heat medium from the devices to be heat-exchanged and a power of a compressor in the refrigeration cycle is estimated not to exceed a heat amount necessary for heating of the vehicle interior, the first circulation portion and the second circulation portion switch the flow of the heat medium such that the heater, the heating heat exchanger, and one bypass flow path of the first and second bypass flow paths are included in one circulation circuit of the first and second circulation circuits, and such that the cooler and the radiator flow path are included in the other circulation circuit of the first and second circulation circuits, and

when the total is estimated to exceed the heat amount, the first circulation portion and the second circulation portion switch the flow of the heat medium such that the heater, the heating heat exchanger, and the one bypass flow path are included in the one circulation circuit, and such that at least one of the devices to be heat-exchanged, the cooler, and the other bypass flow path of the first and second bypass flow paths are included in the other circulation circuit of the first and second circulation circuits.

7. The thermal management system for a vehicle according to claim 3, wherein

the cooler is a low-pressure side heat exchanger of a refrigeration cycle, and

the heater is a high-pressure side heat exchanger of the refrigeration cycle,

when a total of an amount of heat dissipation into the heat medium from the devices to be heat-exchanged and a power of a compressor in the refrigeration cycle is estimated not to exceed a heat amount necessary for heating of the vehicle interior, the first circulation portion and the second circulation portion switch the flow of the heat medium such that the heater, the heat medium-heat medium heat exchanger, and one bypass flow path of the first and second bypass flow paths are included in one circulation circuit of the first and second circulation circuits, and such that the cooler and the radiator flow path are included in the other circulation circuit of the first and second circulation circuits, and

when the total is estimated to exceed the heat amount, the first circulation portion and the second circulation portion switch the flow of the heat medium such that the heater, the heat medium-heat medium heat exchanger, and the one bypass flow path are included in the one circulation circuit, and such that at least one of the devices to be heat-exchanged, the cooler, and the other bypass flow path of the first and second bypass flow paths are included in the other circulation circuit of the first and second circulation circuits.

8. The thermal management system for a vehicle according to claim 2, wherein

the cooler is a low-pressure side heat exchanger of a refrigeration cycle, and

the heater is a high-pressure side heat exchanger of the refrigeration cycle, wherein

when a total of an amount of heat generated by the devices to be heat-exchanged and an amount of heat dissipation into the heat medium from the high-pressure side heat exchanger is estimated not to exceed a heat amount necessary for heating of the vehicle interior, the first circulation portion and the second circulation portion switch the flow of the heat medium such that the heater, the heating heat exchanger, and one bypass flow path of the first and second bypass flow paths are included in one circulation circuit of the first and second circulation circuits, and such that the cooler and the radiator flow path are included in the other circulation circuit of the first and second circulation circuits, and

when the total is estimated to exceed the heat amount, the first circulation portion and the second circulation portion switch the flow of the heat medium such that the heater, the heating heat exchanger, and the one bypass flow path are included in the one circulation circuit, and such that at least one of the devices to be heat-exchanged, the cooler, and the other bypass flow path of the first and second bypass flow paths are included in the other circulation circuit of the first and second circulation circuits.

9. The thermal management system for a vehicle according to claim 3, wherein

the cooler is a low-pressure side heat exchanger of a refrigeration cycle, and

the heater is a high-pressure side heat exchanger of the refrigeration cycle, wherein

when a total of an amount of heat generated by the devices to be heat-exchanged and an amount of heat dissipation into the heat medium from the high-pressure side heat exchanger is estimated not to exceed a heat amount necessary for heating of the vehicle interior, the first circulation portion and the second circulation portion switch the flow of the heat medium such that the heater, the heat medium-heat medium heat exchanger, and one bypass flow path of the first and second bypass flow paths are included in one circulation circuit of the first and second circulation circuits, and such that the cooler and the radiator flow path are included in the other circulation circuit of the first and second circulation circuits, and

when the total is estimated to exceed the heat amount, the first circulation portion and the second circulation portion switch the flow of the heat medium such that the heater, the heat medium-heat medium heat exchanger, and the one bypass flow path are included in the one circulation circuit, and such that at least one of the devices to be heat-exchanged, the cooler and the other bypass flow path of the first and second bypass flow paths are included in the other circulation circuit of the first and second circulation circuits.

10. The thermal management system for a vehicle according to claim 1, wherein

the cooler is a low-pressure side heat exchanger of the refrigeration cycle,

the heater is a high-pressure side heat exchanger of the refrigeration cycle, and

at least one of the devices to be heat-exchanged is a heat storage member capable of storing therein hot heat, and

when frost is estimated to be formed on the radiator, the first circulation portion and the second circulation portion switch the flow of the heat medium such that the devices to be heat-exchanged serving as the heat storage member, the cooler, and the radiator flow path are included in one circulation circuit of the first and second circulation circuits, and such that the heater, and one bypass flow path of the first and second bypass flow paths are included in the other circulation circuit of the first and second circulation circuits.

11. The thermal management system for a vehicle according to claim 1, wherein

the cooler is a low-pressure side heat exchanger of a refrigeration cycle,

the heater is a high-pressure side heat exchanger of the refrigeration cycle, and

at least one of the devices to be heat-exchanged is a heat storage member capable of storing therein hot heat, and

when frost is estimated to be formed on the radiator, the first circulation portion and the second circulation portion switch the flow of the heat medium such that the devices to be heat-exchanged serving as the heat storage member, the cooler, and one bypass flow path of the first and second bypass flow paths are included in one circulation circuit of the first and second circulation circuits, and such that the heater, and the radiator flow path are included in the other circulation circuit of the first and second circulation circuits.

12. The thermal management system for a vehicle according to claim 1, wherein

the cooler is a low-pressure side heat exchanger of a refrigeration cycle,

the heater is a high-pressure side heat exchanger of the refrigeration cycle, and

at least one of the devices to be heat-exchanged is a heat storage member capable of storing therein hot heat, and

when a temperature of the device to be heat-exchanged as the heat storage member is higher than a predetermined temperature, the first circulation portion and the second circulation portion switch the flow of the heat medium such that the devices to be heat-exchanged serving as the heat storage member, the cooler, and one bypass flow path of the first and second bypass flow paths are included in one circulation circuit of the first and second circulation circuits, and such that the heater, and the other bypass flow path of the first and second bypass flow paths are included in the other circulation circuit of the first and second circulation circuits.

13. The thermal management system for a vehicle according to claim 1, further comprising:

a blower blowing air in a vehicle interior;

a casing forming an air passage through which the air flows; and

an air flow switching device switching a flow of the air in the air passage, wherein

one of the devices to be heat-exchanged is a battery heat exchanger that exchanges heat between a battery and the heat medium via air,

the battery and the battery heat exchanger are disposed in the air passage, and

the casing is provided with an air discharge port that discharges the air having flowed through the air passage to an outside of the vehicle,

the air flow switching device is capable of switching between a first air flow state of allowing the air to flow through the battery heat exchanger, the battery, and the air discharge port in that order, and a second air flow state of allowing the air to flow through the battery, the battery heat exchanger, and the air discharge port in that order,

in a case of transferring hot heat from the air to the heat medium, when a temperature of the battery is higher than that of the air, the air flow switching device switches the air flow to the second air flow state, whereas when a temperature of the battery is lower than that of the air, the air flow switching device switches the air flow to the first air flow state, and

in a case of transferring cold heat from the air to the heat medium, when a temperature of the battery is higher than that of the air, the air flow switching device switches the air flow to the first air flow state, whereas when a temperature of the battery is lower than that of the air, the air flow switching device switches the air flow to the second air flow state.

14. The thermal management system for a vehicle according to claim 1, further comprising:

a blower blowing air in a vehicle interior;

a casing forming an air passage through which the air flows; and

an air flow switching device switching a flow of the air in the air passage, wherein

one of the devices to be heat-exchanged is a battery heat exchanger that exchanges heat between a battery and the heat medium via air,

the battery and the battery heat exchanger are disposed in the air passage, and

the casing is provided with an air discharge port through which the air having flowed through the air passage is discharged to an outside of the vehicle,

the air flow switching device is capable of switching between a first air flow state of allowing the air to flow through the battery heat exchanger, the battery, and the air discharge port in that order, and a second air flow state of allowing the air to flow through the battery, the battery heat exchanger, and the air discharge port in that order,

in a case of transferring hot heat from the air to the heat medium, when a temperature of the battery is higher than that of the air, the air flow switching device switches the air flow to the second air flow state, whereas when a temperature of the battery is lower than that of the air, the air flow switching device switches the air flow to the first air flow state, and

in a case of transferring cold heat from the air to the heat medium, when a temperature of the battery is higher than that of the air, the air flow switching device switches the air flow to the first air flow state, whereas when a temperature of the battery is lower than that of the air, the air flow switching device switches the air flow to the second air flow state.

15. The thermal management system for a vehicle according to claim 1, further comprising:

a blower blowing air in a vehicle interior; and

a casing forming an air passage through which the air flows, wherein

one of the devices to be heat-exchanged is a battery heat exchanger that exchanges heat between a battery and the heat medium, wherein

the casing is provided with an air discharge port through which the air having flowed through the air passage is discharged to an outside of the vehicle,

the battery heat exchanger and the battery are arranged in the air passage so as to allow the air to flow therethrough in that order,

when hot heat is transmitted from the air to the heat medium, the first circulation portion and the second circulation portion switch the flow of the heat medium such that the battery heat exchanger and the cooler are included in one circulation circuit of the first and second circulation circuits, and

when cold heat is transmitted from the air to the heat medium, the first circulation portion and the second circulation portion switch the flow of the heat medium such that the battery heat exchanger and the heater are included in one circulation circuit of the first and second circulation circuits.

16. The thermal management system for a vehicle according to claim 15, wherein

when a temperature of the battery is equal to or lower than a predetermined value, the first circulation portion and the second circulation portion switch the flow of the heat medium such that the cooler, the device to be heat-exchanged among the devices to be heat-exchanged other than the battery heat exchanger, and one bypass flow path of the first and second bypass flow paths or the radiator flow path are included in one circulation circuit of the first and second circulation circuits, and such that the battery heat exchanger, the heater, and the other bypass flow path of the first and second bypass flow paths are included in the other circulation circuit of the first and second circulation circuits.

17. The thermal management system for a vehicle according to claim 16, wherein the predetermined value is 0°

C.

18. The thermal management system for a vehicle according to claim 1, wherein

the cooler is a low-pressure side heat exchanger of the refrigeration cycle, and

the heater is a high-pressure side heat exchanger of the refrigeration cycle,

the thermal management system includes a heat medium-refrigerant heat exchanger exchanging heat between the heat medium flowing through one of the device flow paths, and refrigerant flowing from the heater,

the refrigeration cycle includes a cooling heat exchanger that exchanges heat between the refrigerant and air to be blown into the vehicle interior to cool the air, and

when the vehicle interior is cooled by the air cooled by the cooling heat exchanger, the heat medium-refrigerant heat exchanger and the battery heat exchanger are included in one circulation circuit of the first and second circulation circuits.

19. The thermal management system for a vehicle according to claim 18, wherein the heat medium-refrigerant heat exchanger and the battery heat exchanger are arranged in series in one device flow path of the device flow paths.

20. The thermal management system for a vehicle according to claim 18, wherein an expansion valve decompressing and expanding the refrigerant having flowed from the heater is disposed between the heater and the heat medium-refrigerant heat exchanger in the refrigeration cycle.

21. The thermal management system for a vehicle according to claim 20, wherein

when the vehicle interior is heated and a temperature of the vehicle interior is higher than an outside air temperature,

the first circulation portion and the second circulation portion switch the flow of the heat medium such that the battery heat exchanger, the heat medium-refrigerant heat exchanger, and the cooler are included in one circulation circuit of the first and second circulation circuits, and

the expansion valve decompresses and expands the refrigerant flowing from the heat exchanger such that a refrigerant pressure in the heat medium-refrigerant heat exchanger is a pressure positioned between a refrigerant pressure in the heater and a refrigerant pressure in the cooler, and such that an evaporation temperature of a refrigerant in the heat medium-refrigerant heat exchanger is lower than that of the heat medium circulating through the heat medium-refrigerant heat exchanger.

22. The thermal management system for a vehicle according to claim 20, wherein

when the vehicle interior is heated and a temperature of the vehicle interior is higher than an outside air temperature,

the first circulation portion and the second circulation portion switch the flow of the heat medium such that the battery heat exchanger, the heat medium-refrigerant heat exchanger, and the cooler are included in one circulation circuit of the first and second circulation circuits, and

the expansion valve decompresses and expands the refrigerant flowing from the heater such that a refrigerant pressure in the heat medium-refrigerant heat exchanger is a pressure positioned between a refrigerant pressure in the heater and a refrigerant pressure in the cooler, and such that an evaporation temperature of a refrigerant in the heat medium-refrigerant heat exchanger is lower than that of the heat medium circulating through the heat medium-refrigerant heat exchanger.

23. The thermal management system for a vehicle according to claim 13, wherein,

when the vehicle interior is heated and a temperature of the vehicle interior is higher than an outside air temperature, the first circulation portion and the second circulation portion switch the flow of the heat medium such that the battery heat exchanger, the heat medium-refrigerant heat exchanger, and the cooler are included in one circulation circuit of the first and second circulation circuits.

24. The thermal management system for a vehicle according to claim 1, wherein

the second circulation portion has a first switching valve that distributes the heat media for the two systems with respect to the second flow path group, and a second switching valve that collects the heat media for the two systems with respect to the second flow path group,

the first switching valve has a first inlet for inflow of the heat medium discharged from the first pump, a second inlet for inflow of the heat medium discharged from the second pump, and a number of outlets for outflow of the heat medium individually with respect to the cooler flow path, the heater flow path, and the device flow paths, and

the second switching valve has a first outlet for outflow of the heat medium to be sucked by the first pump, a second outlet for outflow of the heat medium to be sucked by the second pump, and a number of inlets for individual inflow of the heat medium having flowed from the cooler flow path, the heater flow path, and the device flow paths.

25. The thermal management system for a vehicle according to claim 24, wherein

the first circulation portion includes:

a three-way valve connected to the first outlet, an inlet side of the radiator flow path, and an inlet side of one bypass flow path of the first and second bypass flow paths;

a first communication flow path for communication between the second outlet and the other bypass flow path of the first and second bypass flow paths;

a merging flow path for communication among an outlet side of the radiator flow path, an outlet side of the one bypass flow path, and the first inlet; and

a second communication flow path for communication between the other bypass flow path and the second inlet, and wherein

the first pump is disposed between the merging flow path and the first inlet, and

the second pump is disposed between the second communication flow path and the second inlet.

26. The thermal management system for a vehicle according to claim 24, wherein

the first circulation portion includes:

a branch flow path for communication among the first outlet, an inlet side of the radiator flow path, and an inlet side of one bypass flow path of the first and second bypass flow paths;

a first communication flow path for communication between a second outlet of the second switching valve and the other bypass flow path of the first and second bypass flow paths;

a three-way valve connected to an outlet side of the radiator flow path, an outlet side of the one bypass flow path, and the first inlet; and

a second communication flow path for communication between the other bypass flow path and a second inlet of the first switching valve, wherein

the first pump is disposed between the first outlet and the branch flow path, and

the second pump is disposed between the second outlet and the first communication flow path.

27. The thermal management system for a vehicle according to claim 24, further comprising:

a temperature detector detecting a temperature of the heat medium flowing into the first inlet and a temperature of the heat medium flowing into the second inlet, wherein

the first switching valve includes a mixing space that mixes the heat medium flowing into the first inlet and the heat medium flowing into the second inlet, and a valve body that adjusts a mixing ratio of the heat medium flowing into the first inlet to the heat medium flowing into the second inlet based on a temperature of the heat medium required by the devices to be heat-exchanged, and

the second switching valve includes a distribution space that distributes the heat medium flowing into a number of inlets to the heat medium flowing from the first outlet and the heat medium flowing from the second outlet, and a valve body that adjusts a distribution ratio of the heat medium flowing from the first outlet to the heat medium flowing from the second outlet based on the mixing ratio.

28. The thermal management system for a vehicle according to claim 1, wherein

the cooler is a low-pressure side heat exchanger in a refrigeration cycle and cools the heat medium by exchanging heat between a low-pressure refrigerant in the refrigeration cycle and the heat medium, and

the heater is a high-pressure side heat exchanger in the refrigeration cycle, and heats the heat medium by exchanging heat between a high-pressure refrigerant in the refrigeration cycle and the heat medium.

29. The thermal management system for a vehicle according to claim 28, wherein

the refrigeration cycle includes:

a first expansion valve decompressing a refrigerant flowing into the cooler;

a cooling heat exchanger that exchanges heat between the low-pressure refrigerant and air to be blown into the vehicle interior to cool the air, the heat exchanger being adapted to allow the low-pressure refrigerant to flow therethrough in parallel with the cooler;

a second expansion valve decompressing a refrigerant flowing into the cooling heat exchanger; and

an electromagnetic valve opening or closing a refrigerant flow path between the first expansion valve and a branch portion that branches a flow of the refrigerant into a side of the cooler and a side of the cooling heat exchanger.

30. The thermal management system for a vehicle according to claim 1, wherein the heat medium is a fluid containing nanoparticles with a particle diameter of the order of nanometer.

31. The thermal management system for a vehicle according to claim 30, wherein an aspect ratio of the nanoparticle is 50 or more.

32. The thermal management system for a vehicle according to claim 31, wherein a constituent atom of the nanoparticle includes one of Au, Ag, Cu, and C.

33. The thermal management system for a vehicle according to claim 32, wherein the nanoparticle includes at least one of a carbon nanotube, a graphene, and a graphite.