Vehicle Thermal Management Systems

Abstract

To attain both of a function for obtaining high cooling performance by using a heat pump and a function for obtaining high electric power consumption performance through exhaust heat recovery in a vehicular cooling system for cooling a plurality of heating elements.SOLUTION: A vehicular heat management system includes: a first cooling circuit 4 cooling a first heating element 1; a second cooling circuit 8 for cooling a second heating element 5; a third cooling circuit 12 for cooling a third heating element 9; a first heat exchanger 13 exchanging heat between the third cooling circuit 12 and the first cooling circuit 4; and a second heat exchanger 14 exchanging heat between the third cooling circuit 12 and the second cooling circuit 8. The third cooling circuit 12 includes: a compressor 11 compressing a refrigerant; an expander 10 expanding the refrigerant; and a path switching mechanism for switching a refrigerant circulation path. The vehicular heat management system further includes: a refrigerant driving body 16 for circulating the refrigerant in the third cooling circuit 12; and a main controller 50 controlling the path switching mechanism.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle thermal management system to be installed in various vehicles such as automobiles. [Background technology]

[0002] A conventional vehicle thermal management system is described in Patent Document 1, which is called a vapor compression refrigerator. The system described in Patent Document 1 has two cooling systems, one for cooling the motor and one for cooling the engine, and heat is exchanged between these cooling systems. In the motor and engine cooling circuits, which are configured to circulate an antifreeze refrigerant using a pump, the waste heat from the motor and engine is transported to the adjacent battery cooling circuit via a heat exchanger. The battery cooling circuit has a refrigeration cycle using a heat pump, in which pressurized refrigerant inside the heat pump is ejected from an ejector nozzle, converting the refrigerant's pressure energy into velocity energy to isentropically depressurize and expand the refrigerant.

[0003] The system uses the entrainment action of the high-speed refrigerant flow sprayed from the ejector nozzle to draw in the evaporated gas-phase refrigerant, converting velocity energy into pressure energy to increase the refrigerant pressure, and also increases the refrigerant pressure in the refrigeration cycle, which is then reduced in pressure by an expansion valve, thereby lowering the temperature of outside air in the evaporator and supplying it to the battery cooling circuit. In this way, the system cools the battery cooling circuit and uses energy recovered from the exhaust heat of the motor and engine as pressure energy for the heat pump, thereby improving power efficiency. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-177588 Summary of the Invention [Problem to be solved by the invention]

[0005] However, conventional systems have a cooling system with a heat pump refrigeration cycle, which means that the heat pump cannot recover heat effectively when cooling is not required. Furthermore, conventional systems require an air radiator separate from the radiator for the motor and engine for the heat recovery Rankine cycle or heat pump refrigeration cycle.

[0006] The present invention has been made in consideration of the above-mentioned conventional situation, and aims to provide a vehicle cooling system that cools multiple heat-generating elements, and that can achieve both high cooling performance using a heat pump with a refrigeration cycle and high power efficiency through exhaust heat recovery without increasing the size of the heat dissipation section to the air. [Means for solving the problem]

[0007] The vehicle thermal management system according to the present invention cools a first heat generating element. No. 1 The first cooling circuit circulates the refrigerant, and the second cooling circuit cools the heating element. No. 2 The second cooling circuit circulates the refrigerant and the third heating element. Third The cooling system includes a third cooling circuit that circulates the refrigerant, a first heat exchanger that exchanges heat between the third cooling circuit and the first cooling circuit, and a second heat exchanger that exchanges heat between the third cooling circuit and the second cooling circuit. The third cooling circuit includes a compressor that compresses the refrigerant, an expander that expands the refrigerant, and a path switching mechanism that switches the refrigerant circulation path. , th 3rd refrigerant of 3 cooling circuits Converts energy into and a main controller that controls the path switching mechanism. hand And the vehicle thermal management system The main controller controls the path switching mechanism so that the third refrigerant passes through the first heat exchanger and the third refrigerant passes through the second heat exchanger during operation in the exhaust heat recovery mode. It is characterized by the following. [Effects of the Invention]

[0008] By adopting the above-mentioned configuration, the vehicle heat exchange system of the present invention is able to achieve both the function of obtaining high cooling performance using a heat pump with a refrigeration cycle and the function of achieving high power consumption performance through exhaust heat recovery in a vehicle cooling system that cools multiple heat generating elements, and moreover, it is possible to achieve both the above-mentioned cooling performance and power consumption performance without increasing the size of the heat dissipation section to the air. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a circuit diagram showing a first embodiment of a vehicle thermal management system of the present invention. [Figure 2] FIG. 2 is a circuit diagram showing operation of the system shown in FIG. 1 in a cooling mode. [Figure 3] FIG. 2 is a circuit diagram showing another cooling mode operation of the system shown in FIG. [Figure 4] FIG. 2 is a circuit diagram showing an operation of the system shown in FIG. 1 in an exhaust heat recovery mode. [Figure 5] FIG. 4 is a circuit diagram showing a second embodiment of a vehicle thermal management system according to the present invention. [Figure 6] FIG. 4 is a circuit diagram showing a third embodiment of a vehicle thermal management system according to the present invention. [Figure 7] FIG. 10 is a circuit diagram showing a fourth embodiment of a vehicle thermal management system according to the present invention. [Figure 8] FIG. 10 is a circuit diagram showing a fifth embodiment of a vehicle thermal management system according to the present invention. [Figure 9] FIG. 9 is a circuit diagram showing the operation of the system shown in FIG. 8 in a cooling mode. [Figure 10] FIG. 9 is a circuit diagram showing another cooling mode operation of the system shown in FIG. 8. [Figure 11] FIG. 9 is a circuit diagram showing an operation of the system shown in FIG. 8 in an exhaust heat recovery mode. [Figure 12] FIG. 10 is a circuit diagram showing a sixth embodiment of a vehicle thermal management system according to the present invention. [Figure 13] FIG. 10 is a circuit diagram showing a seventh embodiment of a vehicle thermal management system according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] First Embodiment 1 includes a first cooling circuit 4 that circulates a refrigerant that cools a first heating element 1, a second cooling circuit 8 that circulates a refrigerant that cools a second heating element 5, and a third cooling circuit 12 that circulates a refrigerant that cools a third heating element 9. The vehicle thermal management system also includes a first heat exchanger 13 that exchanges heat between the third cooling circuit 12 and the first cooling circuit 4, and a second heat exchanger that exchanges heat between the third cooling circuit and the second cooling circuit.

[0011] Furthermore, the third cooling circuit 12 forms a refrigeration cycle with a compressor 11 that compresses the refrigerant and an expander 10 that expands the refrigerant, and is equipped with a path switching mechanism that switches the refrigerant circulation path.The vehicle thermal management system also includes a refrigerant driver that drives the refrigerant to circulate in the third cooling circuit 12, and a main controller 50 that controls the path switching mechanism.

[0012] As an example, the first heating element 1 is a motor, the second heating element 5 is an engine, and the third heating element 9 is a generator. In this case, the refrigerant circulating in the first cooling circuit 4 and the second cooling circuit 8 is water. The refrigerant circulating in the third cooling circuit 12 is a heat pump refrigerant, which is made high-pressure and high-temperature by the compressor 11 and low-pressure and low-temperature by the expander 10. The refrigerant driver in this embodiment is a turbine 16 that converts the pressure energy of the vaporized refrigerant in the third cooling circuit 12 into rotational energy, and is connected to the power shaft of the third heating element (generator) 9.

[0013] The vehicle thermal management system of the illustrated example includes a third cooling circuit 12 provided with a third heat exchanger 15 on the discharge port side of the compressor 11, which exchanges heat with the first cooling circuit 2. The third cooling circuit 12 includes a first bypass flow path 17 that bypasses the first heat exchanger 13, and a first switching valve 18 that opens and closes the first bypass flow path 17. The third cooling circuit 12 also includes a second bypass flow path 21 that bypasses the second heat exchanger 14, and a second switching valve 22 that opens and closes the second bypass flow path 21.

[0014] Furthermore, the third cooling circuit 12 includes a third bypass flow path 19 that bypasses the third heat exchanger 15, and a third switching valve 20 that opens and closes the third bypass flow path 19. The aforementioned path switching mechanism is made up of these bypass flow paths 17, 21, 19 and switching valves 18, 22, 20, and the main controller 50 controls the switching valves 18, 22, 20.

[0015] The first cooling circuit 4 includes a first pump 2 that drives the refrigerant and a first radiator 3 that dissipates heat from the refrigerant, and also includes a fourth bypass flow path 25 that bypasses the first heating element 1 and a fourth switching valve 26 that opens and closes the fourth bypass flow path 25 between the first radiator 3 and the first heat exchanger 13.

[0016] The second cooling circuit 8 includes a second pump 6 that drives the refrigerant, a second radiator 7 that dissipates heat from the refrigerant, a fifth bypass flow path 23 that bypasses the second radiator 7, and a fifth switching valve 24 that opens and closes the fifth bypass flow path 23. The path switching mechanism can include these bypass flow paths 25, 23 and switching valves 26, 24, and the switching valves 26, 24 can be controlled by a main controller 50.

[0017] In the vehicle thermal management system having the above configuration, the first cooling circuit 4 circulates the refrigerant using the first pump 2, the refrigerant absorbs heat from the first heating element 1, and the first radiator 3 releases the heat to the air. The second cooling circuit 8 circulates the refrigerant using the second pump 6, the refrigerant absorbs heat from the second heating element 5, and the second radiator 7 releases the heat to the air.

[0018] The third cooling circuit 12 compresses the refrigerant in the compressor 11 to make it high-pressure and high-temperature, and expands the refrigerant in the expansion valve 10 to make it low-pressure and low-temperature, and supplies the low-pressure, low-temperature refrigerant to the third heating element 9, thereby cooling the third heating element 9 by boiling cooling at low temperature and involving a phase change. As a result, the third cooling circuit 12 can prevent the third heating element 9 from becoming too hot even if the heat generation density of the third heating element 9 is high, and can increase the continuous rated output.

[0019] FIG. 2 is a diagram showing operation in cooling mode in the vehicle thermal management system shown in FIG. 1, and particularly shows the operating state in which heat from the third heating element 9 is dissipated into the air from the radiator 3 for the first heating element by the heat pump of the third cooling circuit 12.

[0020] During the cooling mode, the main controller 50 controls the first switching valve 18 to open the first bypass flow path 17 to bypass the first heat exchanger 13, and the second switching valve 22 to open the second bypass flow path 21 to bypass the second heat exchanger 14.

[0021] At this time, in the vehicle thermal management system, when the refrigerant temperature in the third cooling circuit 12 becomes higher than the refrigerant temperature in the first cooling circuit 4, heat is transferred from the refrigerant in the third cooling circuit 12 to the refrigerant in the first cooling circuit 4, as shown by the arrow in the third heat exchanger 15. Then, the heat pump in the third cooling circuit 12 dissipates heat from the third heating element 9 to the air from the first radiator 3 in the first cooling circuit 4 until the refrigerant temperature in the first cooling circuit 4 reaches its maximum temperature.

[0022] In this way, when the second heating element 5 generates more heat or the heat density is higher than that of the first heating element 1, the temperature of the second cooling circuit 8 will be higher than that of the first cooling circuit 4, and the vehicle thermal management system will transport heat at a lower temperature until the refrigerant temperature of the first cooling circuit 4 reaches its maximum temperature, thereby maintaining high efficiency of the heat pump of the third cooling circuit 12.

[0023] FIG. 3 is a diagram showing operation in another cooling mode in the vehicle thermal management system shown in FIG. 1, and particularly shows an operating state in which heat from the third heating element 9 is dissipated into the air from the second heating element radiator 7 by the heat pump of the third cooling circuit 12.

[0024] During the cooling mode, the main controller 50 controls the first switching valve 18 to open the first bypass flow path 17 to bypass the first heat exchanger 13, and the third switching valve 20 to open the third bypass flow path 19 to bypass the third heat exchanger 15.

[0025] At this time, in the vehicle thermal management system, when the refrigerant temperature in the third cooling circuit 12 becomes higher than the refrigerant temperature in the second cooling circuit 8, heat is transferred from the refrigerant in the third cooling circuit 12 to the refrigerant in the second cooling circuit 8, as shown by the arrow in the second heat exchanger 14. Then, the heat pump in the third cooling circuit 12 dissipates heat from the third heating element 9 to the air from the first radiator 7 in the second cooling circuit 8 until the refrigerant temperature in the second cooling circuit 8 reaches its maximum temperature.

[0026] Here, if the first heating element 1 causes the refrigerant temperature in the first cooling circuit 4 to reach its maximum temperature, the operation shown in Fig. 2 is not possible, and so it is necessary to significantly increase the heat dissipation capacity of the first radiator 3. Also, if the heat resistance temperature of the first heating element 1 is lower than that of the second heating element 5, it is necessary to enlarge the first radiator 3.

[0027] Therefore, in the above-mentioned vehicle thermal management system, when the refrigerant temperature in the first cooling circuit 4 reaches its maximum temperature due to the first heating element 1, the temperature difference T between the second cooling circuit 8 of the second heating element 5 and the air can be ensured by operating as shown in Figure 3, and since there is no need to increase the size of the second radiator 7, the maximum continuous rated output can be increased while using a limited radiator size.

[0028] Fig. 4 is a diagram showing operation in an exhaust heat recovery mode in the vehicle thermal management system shown in Fig. 1. In this case, the main controller 50 controls the third switching valve 20 to open the third bypass flow path 19.

[0029] At this time, in the vehicle thermal management system, the compressor 11 plays the role of the pump in the Rankine cycle, the second heat exchanger 14 plays the role of the boiler, and the first heat exchanger 13 plays the role of the condenser. As a result, the vehicle thermal management system converts the heat of the second heating element (engine) 5 into rotational energy by the turbine 16, and also converts the rotational energy into electrical energy by the third heating element (generator) 9 mechanically coupled to this turbine 16.

[0030] That is, in the vehicle thermal management system, in the third cooling circuit 12, the compressor 11 causes the liquid refrigerant to pass through the second heat exchanger 14, and if the refrigerant temperature in the third cooling circuit 12 is higher than that of the second cooling circuit 8, heat is transferred from the refrigerant in the second cooling circuit 8 to the refrigerant in the third cooling circuit 12, as shown by the arrow in the second heat exchanger 14, and the refrigerant in the third cooling circuit 12 boils and becomes a high-temperature, high-pressure gas.

[0031] In the vehicle thermal management system, the vaporized high-temperature, high-pressure refrigerant passes through the turbine 16 and is reduced in pressure, becoming a low-temperature, low-pressure gas. At this time, the enthalpy of the gas decreases in the third cooling circuit 12, and the energy of the gas is converted into rotational energy of the turbine 16, which is then regenerated as electrical energy by the third heating element 9.

[0032] In the third cooling circuit 12, the refrigerant that has become a low-temperature, low-pressure gas passes through the first heat exchanger 13. At this time, if the refrigerant temperature in the first cooling circuit 4 is lower than that in the circuit, heat is transferred as shown by the arrows in the first heat exchanger 13, and the refrigerant in the circuit is condensed and becomes a liquid. The refrigerant that has become a liquid is passed through the second heat exchanger 14 by the compressor 11, thereby enabling a continuous Rankine cycle for exhaust heat recovery.

[0033] Furthermore, in the first cooling circuit, the fourth bypass flow path 25 is opened by the fourth switching valve 26 to bypass the first heating element 1, thereby lowering the refrigerant temperature, and in the second cooling circuit 8, the fifth bypass flow path 23 is opened by the fifth switching valve 24 to bypass the second radiator 7, thereby increasing the refrigerant temperature. This function corresponds to increasing the temperature difference between the boiler and condenser of the Rankine cycle, and improves the efficiency of exhaust heat recovery.

[0034] The vehicle thermal management system of the above embodiment is a vehicle cooling system that cools multiple heat generating elements 1 to 3, and is capable of achieving both high cooling performance using a heat pump with a refrigeration cycle and high power consumption performance through exhaust heat recovery, and moreover, is capable of achieving both the above cooling performance and power consumption performance without increasing the size of the heat dissipation section to the air.

[0035] In addition, the above-mentioned vehicle thermal management system employs a turbine 16 as a refrigerant driver that converts the pressure energy of vaporized refrigerant into rotational energy. By connecting this turbine 16 to the third heating element (generator) 9, this kinetic energy can be utilized to operate the Rankine cycle for exhaust heat recovery, thereby achieving improved electricity efficiency.

[0036] Furthermore, since the above-mentioned vehicle thermal management system connects the turbine 16 to the power shaft of the third heating element 9, an additional generator motor is not required in the exhaust heat recovery mode, and the piping path for the refrigerant in the third cooling circuit 12 can be shortened, thereby simplifying the system structure.

[0037] Furthermore, the above-mentioned vehicle thermal management system employs a third heat exchanger 15 in addition to the first heat exchanger 13 and the second heat exchanger 14, and as a path switching mechanism, bypass flow paths 17, 14, 19 and switching valves 18, 22, 20 are arranged for each of the heat exchangers 13, 14, 15, and the main controller 50 controls the selective switching of the paths, thereby enabling the system to accommodate the cooling mode and exhaust heat recovery mode of the third cooling circuit 12 and efficiently cool each of the heat generating elements 1, 5, 9.

[0038] Furthermore, in the above-described vehicle thermal management system, the fourth bypass flow path 25 and the fourth switching valve 26 are arranged in the first cooling circuit 4, and the fourth bypass flow path 23 and the fourth switching valve 20 are arranged in the second cooling circuit 8. Therefore, the exhaust heat recovery efficiency can be further improved by controlling the fourth bypass flow path 25 and the fifth bypass flow path 23 to be open, particularly in the exhaust heat recovery mode.

[0039] 5 to 13 are diagrams illustrating second to seventh embodiments of the vehicle thermal management system according to the present invention. In the following embodiments, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0040] Second Embodiment 5 has a basic configuration equivalent to that of the first embodiment, and the path switching mechanism in the third cooling circuit 12 includes a sixth bypass flow path 27 that bypasses the turbine 16 serving as a refrigerant driver between the third heating element 9 and the compressor 11, and a sixth switching valve 28 that opens and closes the sixth bypass flow path 27. The path switching mechanism also includes a seventh bypass flow path 29 that bypasses the expander 10, and a seventh switching valve 30 that opens and closes the seventh bypass flow path 29.

[0041] The above-described vehicle thermal management system can achieve the same functions and effects as the first embodiment, and can also reduce pressure loss in the circulation path in the cooling mode by passing the refrigerant in the third cooling circuit 12 through the sixth bypass flow path 27 to bypass the turbine 16. Furthermore, the above-described vehicle thermal management system can reduce pressure loss in the circulation path in the exhaust heat recovery mode by passing the refrigerant in the third cooling circuit 12 through the seventh bypass flow path 29 to bypass the expansion valve 10.

[0042] Third Embodiment The vehicle thermal management system shown in FIG. 6 has the same basic configuration as the first embodiment, and is configured such that a turbine 16 as a refrigerant driver is connected to the power shaft of a first heating element (motor) 1.

[0043] The above-described vehicle thermal management system can obtain the same functions and effects as the first embodiment, and in particular, in the exhaust heat recovery mode, compared to when the electrical energy recovered from the exhaust heat is used by the first heating element 1, the thermal energy of the exhaust heat recovery is converted into rotational energy by the turbine 16 mechanically connected to the power shaft of the first heating element 1. In other words, the above-described vehicle thermal management system can improve the efficiency of exhaust heat recovery by not using power conversion.

[0044] Fourth Embodiment The vehicle thermal management system shown in FIG. 7 has the same basic configuration as the first embodiment, and is configured such that a turbine 16 as a refrigerant driver is connected to the power shaft of a second heat generating element (engine) 5.

[0045] The above-described vehicle thermal management system can achieve the same functions and effects as the first embodiment, and in particular, when the second heating element (engine) 5 generates a large amount of heat and the heat density is high during exhaust heat recovery mode, the farther the piping between the second heat exchanger 14 and the turbine 16 is from the second heating element 5, the more heat leaks into the air. Therefore, by positioning the turbine 16 as close as possible to the second heating element 5, heat leakage into the air can be reduced and exhaust heat recovery efficiency can be improved.

[0046] Fifth Embodiment The vehicle thermal management system shown in Figure 8 has the same basic configuration as the first embodiment, and the refrigerant driver is a boost pump 36 that boosts the pressure of the refrigerant in the third cooling circuit 12, and the boost pump 36 is arranged between the third heating element 9 and the compressor 11.

[0047] In the above-described vehicle thermal management system, the refrigerant is circulated in the third cooling circuit 12 by the boost pump 36, the refrigerant is heated to a high temperature and high pressure by the compressor 11, and the refrigerant is also heated to a low temperature and low pressure by the expander 10 before being supplied to the third heating element 9 to cool the third heating element 9. As a result, the above-described vehicle thermal management system uses boiling cooling that involves a low temperature and phase change to prevent the third heating element 9 from overheating even when the heat generation density is high, thereby increasing the continuous rated output.

[0048] In the above-described vehicle thermal management system, when the third cooling circuit 12 is in the cooling mode, particularly when the refrigerant temperature in the first cooling circuit 4 is lower than that in the third cooling circuit 12, the first switching valve 18 opens the first bypass flow path 17 to bypass the first heat exchanger 13, and the second switching valve 22 opens the second bypass flow path 21 to bypass the second heat exchanger 14, as shown in Fig. 9. As a result, the vehicle thermal management system absorbs heat from the refrigerant in the third cooling circuit 12 with the refrigerant in the first cooling circuit 4, as shown by the arrow of the third heat exchanger 15, and releases the heat to the air in the first radiator 3.

[0049] 10, in the vehicle thermal management system, when the third cooling circuit 12 is in another cooling mode, particularly when the refrigerant temperature in the second cooling circuit 8 is lower than that in the third cooling circuit 12, the first bypass flow path 17 is opened by the first switching valve 18 to bypass the first heat exchanger 13. As a result, the vehicle thermal management system absorbs the heat of the refrigerant in the third cooling circuit 12 with the refrigerant in the second cooling circuit 8, as shown by the arrow of the heat exchanger 14 23, and releases the heat to the air in the second radiator 7.

[0050] 11 , in the exhaust heat recovery mode of the third cooling circuit 12, the vehicle thermal management system opens the third bypass flow path 19 with the third switching valve 20 to bypass the third heat exchanger 15. In the first cooling circuit 4, the fourth bypass flow path 25 with the fourth switching valve 26 is opened to bypass the first heating element 1, and in the second cooling circuit 8, the fifth bypass flow path 23 with the fifth switching valve 24 is opened to bypass the second radiator 7.

[0051] In this case, in the first embodiment in which the turbine 16 is used as the refrigerant driver, the refrigerant circulates in the order of the third heating element 9, the turbine 16, the first heat exchanger 13, the compressor 11, the third bypass passage 19, the second heat exchanger 14, and the expander 10, as shown in Fig. 4. In contrast, in the present embodiment in which the boost pump 36 is used as the refrigerant driver, the refrigerant circulates in the order of the third heating element 9, the expander 10, the second heat exchanger 14, the third bypass passage 19, the compressor 11, the first heat exchanger 13, and the boost pump 36, as shown in Fig. 11, i.e., in the reverse direction.

[0052] In other words, in the exhaust heat recovery mode, the vehicle thermal management system of this embodiment has the compressor 11 playing the role of the turbine in the Rankine cycle, the second heat exchanger 14 playing the role of the boiler, the boost pump 36 playing the role of the pump, and the first heat exchanger 13 playing the role of the condenser, thereby achieving the same functions and effects as the first embodiment.

[0053] The vehicle thermal management system converts the heat of the second heating element 5 into rotational energy using the compressor 11, and converts this into electrical energy through regenerative control using the motor of the compressor 11. The vehicle thermal management system also uses the boost pump 36 to pass the liquid refrigerant in the third cooling circuit 12 through the second heat exchanger 14, and if the refrigerant temperature in the third cooling circuit 12 is higher than that of the second cooling circuit 8, heat is transferred from the refrigerant in the second cooling circuit 8 to the liquid refrigerant in the third cooling circuit 12, causing the liquid refrigerant to boil and become a high-temperature, high-pressure gaseous refrigerant.

[0054] The vehicle thermal management system reduces the pressure of high-temperature, high-pressure gas refrigerant to low-temperature, low-pressure gas by passing it from the discharge port to the suction port of the compressor 11. At this time, the enthalpy of the gas decreases, and the energy of the gas is converted into rotational energy of the compressor 11, which is then regenerated as electrical energy by the drive motor of the compressor 11.

[0055] The gaseous refrigerant in the third cooling circuit 12, now at low temperature and pressure, passes through the first heat exchanger 13, and at this time, if the refrigerant temperature in the first cooling circuit 4 is lower, it condenses into liquid refrigerant. This liquid refrigerant is passed through the second heat exchanger 14 by the pressure boost pump 36, thereby enabling the Rankine cycle for exhaust heat recovery to be continuously carried out.

[0056] Furthermore, in the second cooling circuit 8, the refrigerant bypasses the second radiator, thereby maintaining a high refrigerant temperature, and in the first cooling circuit 4, the refrigerant bypasses the first heating element 1, thereby maintaining a low refrigerant temperature, which is equivalent to increasing the temperature difference between the boiler and condenser of the Rankine cycle, thereby improving the exhaust heat recovery efficiency.

[0057] Sixth Embodiment 12 has a basic configuration equivalent to that of the first embodiment, and the path switching mechanism includes a seventh bypass flow path 29 that bypasses the expander 10 in the third cooling circuit 12, and a seventh switching valve 30 that opens and closes the seventh bypass flow path 29. Furthermore, the vehicle thermal management system includes an eighth bypass flow path 32 that bypasses the boost pump 36, and an eighth switching valve 33 that opens and closes the eighth bypass flow path 32.

[0058] The above-described vehicle thermal management system can achieve the same functions and effects as the first embodiment, and can reduce pressure loss in the circulation path by bypassing the boost pump 36 in the cooling mode, and can reduce pressure loss in the circulation path by bypassing the expansion valve 10 in the exhaust heat recovery mode.

[0059] Seventh Embodiment The vehicle thermal management system shown in FIG. 13 has a basic configuration equivalent to that of the first embodiment, and is structured such that the rotating shaft of the boost pump 36 is connected to the rotating shaft of the compressor 11, and a clutch mechanism 31 is provided between the rotating shaft of the boost pump 36 and the rotating shaft of the compressor 11.

[0060] The above-described vehicle thermal management system can achieve the same functions and effects as those of the first embodiment, and in the exhaust heat recovery mode, drives the boost pump 36 connected to the rotating shaft of the compressor 11. At startup, the motor for the compressor 11 rotates the boost pump 36 to send liquid refrigerant, and when the Rankine cycle is operating, the motor for the compressor 11 is controlled to generate power, and at the same time, the boost pump 36 is rotated via the rotating shaft of the compressor 11 to continue sending liquid refrigerant.

[0061] As a result, the above-described vehicle thermal management system can operate more efficiently by using the exhaust heat as rotational energy than when using recovered exhaust heat electrical energy to drive the boost pump 36. Also, since a dedicated motor for the boost pump 36 is not required, the system can be simplified. Furthermore, by separating the boost pump 36 from the rotating shaft of the compressor 11 using the clutch mechanism 31, the above-described vehicle thermal management system can prevent the boost pump 36 from rotating along with the drive of the compressor 11 in the cooling mode, thereby reducing loss due to the co-rotation.

[0062] The configuration of the vehicle thermal management system according to the present invention is not limited to the above-described embodiments and can be modified as appropriate without departing from the spirit of the present invention. For example, the heat generating element may be a motor, an engine, a generator, an inverter, a battery, a heat storage material, etc., and multiple heat exchangers may be arranged in a single cooling circuit. Furthermore, the heat generating elements are not limited in terms of the magnitude relationship between the heat values ​​and heat densities of the individual heat generating elements. [Explanation of symbols]

[0063] 1 First heating element 3. First radiator 4 1st cooling circuit 5 Second heating element 7 Second radiator 8 Second cooling circuit 9 Third heating element 10 Expander 11 Compressor 12 Third cooling circuit 13 1st heat exchanger 14 Second heat exchanger 15 Third heat exchanger 16 Turbine (refrigerant drive unit) 17 First bypass flow path (path switching mechanism) 18 First switching valve (path switching mechanism) 19 Third bypass flow path (path switching mechanism) 20 Third switching valve (path switching mechanism) 21 Second bypass flow path (path switching mechanism) 22 Second switching valve (path switching mechanism) 23 5th bypass flow path (path switching mechanism) 24 5th switching valve (path switching mechanism) 25 Fourth bypass flow path (path switching mechanism) 26 Fourth switching valve (path switching mechanism) 27 6th bypass flow path (path switching mechanism) 28 No. 6 switching valve 29 7th bypass flow path (path switching mechanism) 30 7th switching valve (path switching mechanism) 31 Clutch mechanism 32 8th bypass flow path (path switching mechanism) 33 No. 8 switching valve (path switching mechanism) 36 Pressure boost pump (refrigerant driver) 50 Main Controller

Claims

1. a first cooling circuit that circulates a first refrigerant that cools a first heating element; a second cooling circuit that circulates a second refrigerant that cools a second heating element; a third cooling circuit that circulates a third refrigerant that cools a third heating element; a first heat exchanger that exchanges heat between the third cooling circuit and the first cooling circuit; and a second heat exchanger that exchanges heat between the third cooling circuit and the second cooling circuit, the third refrigeration circuit includes a compressor that compresses the third refrigerant, an expander that expands the third refrigerant, a path switching mechanism that switches a circulation path of the third refrigerant, a refrigerant driver that converts energy of the third refrigerant, and a main controller that controls the path switching mechanism; The vehicle thermal management system is characterized in that the main controller controls the path switching mechanism so that the third refrigerant passes through the first heat exchanger and the third refrigerant passes through the second heat exchanger when operating in an exhaust heat recovery mode.

2. 2. The vehicle thermal management system according to claim 1, wherein the refrigerant driver is a turbine that converts pressure energy of the third refrigerant vaporized in the third cooling circuit into rotational energy.

3. 3. The vehicle thermal management system of claim 2, wherein the turbine is connected to a power shaft of the third heating element.

4. 3. The vehicle thermal management system of claim 2, wherein the turbine is coupled to a power shaft of the first heating element.

5. 3. The vehicle thermal management system of claim 2, wherein the turbine is coupled to a power shaft of the second heating element.

6. 2. The vehicle thermal management system according to claim 1, wherein the refrigerant driver is a pressure boosting pump that boosts the pressure of the third refrigerant in the third cooling circuit.

7. 7. The vehicle thermal management system according to claim 6, wherein the boost pump is disposed between the third heating element and the compressor.

8. 8. The vehicle thermal management system according to claim 7, wherein a rotary shaft of the boost pump is connected to a rotary shaft of the compressor.

9. 9. The vehicle thermal management system according to claim 8, further comprising a clutch mechanism between the rotary shaft of the boost pump and the rotary shaft of the compressor.

10. the first heat exchanger is disposed between the third heating element and the compressor in the third cooling circuit, 2. The vehicle thermal management system of claim 1, wherein the second heat exchanger is disposed in the third cooling circuit between the compressor and the expander.

11. 11. The vehicle thermal management system according to claim 10, further comprising a third heat exchanger, which exchanges heat between the third cooling circuit and the first cooling circuit, on the discharge port side of the compressor in the third cooling circuit.

12. The third cooling circuit has the following as the path switching mechanism: a first bypass flow path that bypasses the first heat exchanger, and a first switching valve that opens and closes the first bypass flow path; a second bypass flow path that bypasses the second heat exchanger, and a second switching valve that opens and closes the second bypass flow path; 12. The vehicle thermal management system according to claim 11, further comprising: a third bypass flow passage that bypasses the third heat exchanger; and a third switching valve that opens and closes the third bypass flow passage.

13. the first cooling circuit includes a first radiator that dissipates heat from the first refrigerant, and a fourth bypass flow path that bypasses the first heating element and a fourth switching valve that opens and closes the fourth bypass flow path between the first radiator and the first heat exchanger, 13. The vehicle thermal management system according to claim 11, wherein the second cooling circuit includes a second radiator that dissipates heat from the second refrigerant, a fifth bypass flow path that bypasses the second radiator, and a fifth switching valve that opens and closes the fifth bypass flow path.

14. 6. The vehicle thermal management system according to claim 3, wherein the path switching mechanism includes a sixth bypass flow path that bypasses the turbine between the third heating element and the compressor in the third cooling circuit, and a sixth switching valve that opens and closes the sixth bypass flow path.

15. The vehicle thermal management system according to any one of claims 3 to 5, characterized in that the path switching mechanism includes a seventh bypass flow path that bypasses the expander in the third cooling circuit, and a seventh switching valve that opens and closes the seventh bypass flow path.

16. 10. The vehicle thermal management system according to claim 6, further comprising: an eighth bypass flow path that bypasses the boost pump; and an eighth switching valve that opens and closes the eighth bypass flow path.

17. 13. The vehicle thermal management system according to claim 12, wherein the refrigerant driver is a turbine that converts pressure energy of the third refrigerant vaporized in the third cooling circuit into rotational energy, and the main controller controls the first switching valve, the second switching valve, and the third switching valve to open the first bypass flow path and one of the second bypass flow path and the third bypass flow path in a cooling mode of the third cooling circuit.

18. 13. The vehicle thermal management system according to claim 12, wherein the refrigerant driver is a turbine that converts pressure energy of the third refrigerant vaporized in the third cooling circuit into rotational energy, and the main controller controls the third switching valve to open the third bypass flow path in an exhaust heat recovery mode of the third cooling circuit.

19. 13. The vehicle thermal management system according to claim 12, wherein the refrigerant driver is a boost pump disposed between the third heating element and the compressor, and the main controller controls the first switching valve and the second switching valve to open at least the first bypass flow path of the first bypass flow path and the second bypass flow path in a cooling mode of the third cooling circuit.

20. 13. The vehicle thermal management system according to claim 12, wherein the refrigerant driver is a boost pump disposed between the third heating element and the compressor, and the main controller controls the third switching valve to open the third bypass flow path in an exhaust heat recovery mode of the third cooling circuit, thereby circulating the refrigerant through the third heating element, the second heat exchanger, and the compressor in that order.

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