Temperature control system for electric vehicle

Abstract

To perform temperature control of a battery with high response by a CO2 refrigerant common to air conditioning of a cabin.SOLUTION: A temperature control system (100) for an electric vehicle includes compressors (CO2, 1b) configured to compress 1a refrigerant, first heat exchangers (2a) configured to cool the refrigerant compressed by the compressors, cooling expansion valves (V1a, V1b) configured to expand the refrigerant cooled by the first heat exchangers, refrigerant passages (13b) configured to supply the refrigerant expanded by the cooling expansion valves to an air conditioner (5) when cooling the air conditioner, refrigerant passages (6a) configured to supply the refrigerant expanded by the cooling expansion valves to a motor (4) when cooling the motor, a common rail () and an injector () configured to expand the refrigerant and inject the refrigerant into a battery case (V2a), and refrigerant passages (1617,) configured to supply the refrigerant after cooling the air conditioner to the common rail and the injector when cooling the air conditioner and when cooling a battery (6). V2b, and a refrigerant passage (14,15,22) for supplying the refrigerant passing through the air conditioner, the motor, and the battery to the compressor.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a temperature control system for an electric vehicle. [Background technology]

[0002] Conventionally, air conditioning systems having a heat cycle circuit that operates with a refrigerant containing CO2 (hereinafter referred to as "CO2 refrigerant") have been known. Also under consideration are a technology in which the heat cycle circuit of an air conditioning system for a passenger compartment of an electric vehicle is thermally coupled to a battery to cool or heat the battery (for example, Patent Document 1), and a cooling system in which low-temperature CO2 is circulated inside a cooling unit to directly cool a vehicle drive motor, inverter, and battery that are sealed in individual packages to each other (for example, Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-68348 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-107453 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, the use of CO2 refrigerant in vehicle cabin air conditioning systems has been considered. In this case, it is conceivable that the CO2 refrigerant used in the thermal cycle circuit of the vehicle cabin air conditioning system could also be used to regulate the temperature of the motor and battery.

[0005] However, since the pressure of the CO2 refrigerant, which is reduced to a low temperature by an expansion valve in the thermal cycle circuit of an air conditioning system, is generally very high at around 5 MPa, if such high-pressure CO2 refrigerant is flowed around the battery cells to directly cool the cells, it becomes necessary to strengthen the battery case and cell structure, resulting in increased battery weight and manufacturing costs.On the other hand, if the cells inside the battery are indirectly cooled via a heat exchanger installed on the outside of the battery case by flowing high-pressure CO2 refrigerant through the heat exchanger, the temperature control response is slower than with the above-mentioned direct cooling, which increases the battery temperature fluctuation range and makes the battery more susceptible to deterioration due to the thermal cycle.

[0006] The present invention has been made to solve these problems, and aims to provide a temperature control system for an electric vehicle that can control the battery temperature with high responsiveness using a CO2 refrigerant that is the same as the CO2 refrigerant used for air conditioning the vehicle cabin. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the present invention provides a temperature control system for an electric vehicle equipped with an air conditioning unit for performing air conditioning, a drive motor, and a battery with cells housed inside a battery case, and is equipped with: a compressor that compresses a refrigerant containing CO2; a first heat exchanger that cools the refrigerant compressed by the compressor; a first expansion valve that expands the refrigerant cooled by the first heat exchanger; an air conditioning cooling path that supplies the refrigerant expanded by the first expansion valve to the air conditioning unit when cooling the air conditioning unit; a motor cooling path that supplies the refrigerant expanded by the first expansion valve to the motor when cooling the motor; a second expansion valve that expands the refrigerant and injects it into the battery case; a first battery cooling path that supplies the refrigerant after cooling the air conditioning unit to the second expansion valve when cooling the air conditioning unit and the battery; and a recovery path that supplies the refrigerant that has passed through the air conditioning unit, the motor, and the battery to the compressor.

[0008] According to the present invention configured as described above, the air conditioning unit, the motor, and the battery are cooled using a common refrigerant containing CO2, thereby enabling the overall temperature control system to be compact. Furthermore, when cooling the air conditioning unit and the battery, the refrigerant used to cool the air conditioning unit is supplied to the second expansion valve, where it is further expanded and injected into the battery case from the second expansion valve. This allows the cells to be directly cooled by the refrigerant while maintaining the structural strength of the battery cells and case at the same level as conventional systems. This allows for highly responsive battery temperature control without increasing battery weight or manufacturing costs.

[0009] In the present invention, preferably, the compressor includes a first compressor that compresses the refrigerant that has passed through the battery, and a second compressor that compresses the refrigerant that has passed through the air conditioning unit and the motor, and when the air conditioning unit and the battery are cooled, the second compressor further compresses the refrigerant compressed by the first compressor.

[0010] According to the present invention configured in this manner, the refrigerant compressed by the first compressor after passing through the battery, the refrigerant that has passed through the air conditioning unit, and the refrigerant that has passed through the motor can all be compressed by the second compressor.Therefore, the second compressor can be used in common to compress the refrigerant used to cool the air conditioning unit, the motor, and the battery, making the overall temperature control system configuration compact.

[0011] In the present invention, the temperature regulation system for an electric vehicle preferably includes a battery heating path that supplies refrigerant compressed by the first compressor to the second expansion valve when the battery is heated.

[0012] According to the present invention configured as described above, the high-temperature, high-pressure refrigerant compressed by the first compressor is expanded and injected into the battery case through the second expansion valve, thereby directly heating the cells with the refrigerant, which allows for highly responsive temperature control of the battery without increasing the battery weight or manufacturing costs.

[0013] In the present invention, the temperature control system for the electric vehicle preferably includes a second heat exchanger that cools the refrigerant compressed by the first compressor when the air conditioning unit is heating or stopped and when the battery is cooling, and a second battery cooling path that supplies the refrigerant cooled by the second heat exchanger to the second expansion valve when the air conditioning unit is heating or stopped and when the battery is cooling.

[0014] According to the present invention configured as described above, the refrigerant that has passed through the battery is compressed by the first compressor, cooled by the second heat exchanger, and then supplied to the second expansion valve via the second battery cooling path. The refrigerant is then expanded and sprayed from the second expansion valve into the battery case. Therefore, even when the air conditioning unit is heating or stopped and the refrigerant that has cooled the air conditioning unit cannot be used, the cells can be directly cooled by the refrigerant that flows through a heat cycle circuit independent of the air conditioning unit. This allows for highly responsive temperature control of the battery without increasing the battery weight or manufacturing costs.

[0015] In the present invention, the second expansion valve preferably has a common rail that stores refrigerant, and an injector that injects the refrigerant stored in the common rail into the inside of the battery case.

[0016] According to the present invention configured in this manner, the required amount of refrigerant according to the heat generation amount and temperature of the battery can be injected from the injector at an appropriate pressure into the inside of the battery case with high precision, thereby suppressing temperature fluctuations in the battery cells and reducing battery deterioration due to thermal cycles.

[0017] In the present invention, the temperature control system for an electric vehicle preferably includes an air conditioning heating path that supplies refrigerant compressed by the compressor to the air conditioning unit when the air conditioning unit is heating.

[0018] According to the present invention configured as described above, the air conditioning unit can be heated by supplying high-temperature, high-pressure refrigerant compressed by the compressor to the air conditioning unit via the air conditioning heating path. [Effects of the Invention]

[0019] According to the temperature regulation system for an electric vehicle of the present invention, the temperature of the battery can be regulated with high responsiveness by using the same CO2 refrigerant as that used for air conditioning the vehicle compartment. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a schematic configuration diagram of a vehicle to which a temperature control system for an electric vehicle according to an embodiment of the present invention is applied; [Figure 2] 1 is a schematic configuration diagram of a temperature control system for an electric vehicle according to an embodiment of the present invention; [Figure 3] 1 is a block diagram showing an electrical configuration of a temperature regulation system for an electric vehicle according to an embodiment of the present invention; [Figure 4] 3 is a flowchart of control executed by the temperature regulation system for an electric vehicle according to an embodiment of the present invention. [Figure 5] 10 is a table showing air conditioning / battery cooperative control patterns according to combinations of air conditioning requests and battery temperature control requests of the temperature regulation system for an electric vehicle according to an embodiment of the present invention. [Figure 6] 1A and 1B are explanatory diagrams showing a PH diagram and a PT diagram of the thermal cycle of the air conditioner and the battery and the flow of the refrigerant in an air conditioning / battery coordinated control pattern 1-a of the temperature adjustment system for an electric vehicle according to an embodiment of the present invention. [Figure 7] 2A and 2B are explanatory diagrams showing a PH diagram and a PT diagram of the thermal cycle of the air conditioner and the battery and the flow of the refrigerant in the air conditioning / battery coordinated control pattern 2-a of the temperature adjustment system for the electric vehicle according to the embodiment of the present invention. [Figure 8] 10 is an explanatory diagram showing a PH diagram and a PT diagram of the thermal cycle of the air conditioner and the battery and the flow of the refrigerant in the air conditioning / battery coordinated control pattern 2-b of the temperature adjustment system for the electric vehicle according to the embodiment of the present invention. FIG. [Figure 9] 3A and 3B are explanatory diagrams showing a PH diagram and a PT diagram of the battery's thermal cycle and the flow of refrigerant in an air conditioning / battery coordinated control pattern 3-a of the temperature adjustment system for an electric vehicle according to an embodiment of the present invention. [Figure 10] 3A and 3B are explanatory diagrams showing a PH diagram and a PT diagram of the battery's thermal cycle and the flow of refrigerant in an air conditioning / battery coordinated control pattern 3-b of the temperature adjustment system for an electric vehicle according to an embodiment of the present invention. [Figure 11] 4A and 4B are explanatory diagrams showing a PH diagram and a PT diagram of the thermal cycle of the air conditioner and the battery and the flow of the refrigerant in the air conditioning / battery coordinated control pattern 4-a of the temperature adjustment system for the electric vehicle according to the embodiment of the present invention. [Figure 12] 4A and 4B are explanatory diagrams showing a PH diagram and a PT diagram of the thermal cycle of the air conditioner and the battery and the flow of the refrigerant in the air conditioning / battery coordinated control pattern 4-b of the temperature adjustment system for the electric vehicle according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A temperature control system for an electric vehicle according to an embodiment of the present invention will now be described with reference to the accompanying drawings.

[0022] [Overall configuration] First, the overall configuration of the temperature regulation system for an electric vehicle according to this embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic configuration diagram of a vehicle to which the temperature regulation system for an electric vehicle according to this embodiment is applied.

[0023] 1, electric vehicle 200 includes a temperature control system 100 having a heat cycle circuit that operates with a refrigerant containing CO2, a motor 4 for driving electric vehicle 200, an air conditioner (air conditioning unit) 5 that conditions the air inside electric vehicle 200, and a battery 6 that supplies power to motor 4. Temperature control system 100 also includes a compressor 1 for compressing the refrigerant and a heat exchanger 2 for cooling the refrigerant compressed by compressor 1.

[0024] The temperature control system 100 circulates a CO2 refrigerant (hereinafter sometimes simply referred to as "refrigerant") as a natural refrigerant. Typically, CO2 refrigerant is a refrigerant containing refrigeration oil (oil) such as PAG and additives. To use such a CO2 refrigerant, the compressor 1 is configured to compress the refrigerant to a very high pressure. The motor 4 uses the refrigerant compressed by the compressor 1 and cooled by the heat exchanger 2 to cool the rotor and stator. Furthermore, the motor 4 is configured to lubricate the sliding bearing that supports the rotating shaft with the refrigerant. The refrigerant compressed by the compressor 1 or the refrigerant cooled by the heat exchanger 2 after compression is used for air conditioning in the air conditioner 5, as well as for cooling or heating the battery 6.

[0025] [Temperature control system configuration] Next, the temperature adjustment system 100 according to this embodiment will be specifically described with reference to Fig. 2. Fig. 2 is a schematic configuration diagram of the temperature adjustment system 100 according to this embodiment.

[0026] The temperature adjustment system 100 forms a heat cycle circuit that circulates the CO2 refrigerant described above, and in addition to the compressor 1 and heat exchanger 2 described above, has refrigerant passages 11-22 through which the refrigerant flows, cooling expansion valves (first expansion valves) V1a, V1b that expand the refrigerant to reduce its pressure, a common rail V2a and an injector V2b, a heating valve V1c, and heat exchanger bypass control valves V3a, V3b and low-pressure refrigerant switching control valves V4a, V4b, V4c that switch the refrigerant passages.

[0027] In this embodiment, the compressor 1 includes a high-pressure compressor 1a (second compressor) that compresses the refrigerant that has passed through the air conditioner 5 and the motor 4, and a low-pressure compressor (first compressor) 1b that compresses the refrigerant that has passed through the battery 6. The high-pressure compressor 1a increases the pressure P2 of the refrigerant to pressure P1 (pressure P1 > pressure P2), and the low-pressure compressor 1b increases the pressure P3 of the refrigerant to pressure P2 (pressure P2 > pressure P3). In one example, the pressure P1 is about 11 MPa, the pressure P2 is about 5 MPa or 2 MPa, and the pressure P3 is about 0.1 MPa.

[0028] The heat exchanger 2 includes a first heat exchanger 2a that cools the refrigerant compressed by the high-pressure compressor 1a, and a second heat exchanger 2b that cools the refrigerant compressed by the low-pressure compressor 1b when the air conditioner 5 is heating or stopped and when the battery 6 is cooling.

[0029] The motor 4 is cooled by a temperature adjustment system 100. Specifically, the refrigerant is compressed by the high-pressure compressor 1a, passes through the first heat exchanger 2a via the refrigerant passage 11 to be cooled, and then expands through the cooling expansion valve V1a to a low temperature before being supplied to the motor 4 through the refrigerant passage (motor cooling path) 12. The refrigerant supplied to the motor 4 cools the motor 4 by absorbing heat as it passes through the stator, rotor, bearings, etc. of the motor 4, and then returns to the high-pressure compressor 1a via the refrigerant passage 14 (recovery path) and the low-pressure refrigerant switching control valve V4c, where it is compressed again.

[0030] The air conditioner 5 is cooled or heated by the temperature adjustment system 100. When the air conditioner 5 is cooled, the refrigerant is compressed by the high-pressure compressor 1a, passes through the first heat exchanger 2a via the refrigerant passage 11, is cooled, and then expands through the cooling expansion valve V1b, becoming cooler than the air inside the vehicle cabin. The refrigerant is then supplied to the air conditioner 5 through the refrigerant passage (air conditioning cooling path) 13b. The refrigerant supplied to the air conditioner 5 absorbs heat as it passes through the vehicle cabin heat exchanger of the air conditioner 5, thereby cooling the air flowing into the vehicle cabin. The refrigerant then passes through the refrigerant passage 15 (recovery path) and the low-pressure refrigerant switching control valve V4c, returns to the high-pressure compressor 1a, and is compressed again. When the battery 6 is cooled, the refrigerant that has passed through the air conditioner 5 is supplied to the battery 6 through the refrigerant passage 16.

[0031] When the air conditioner 5 is heated, the refrigerant is compressed by the high-pressure compressor 1a and expanded by the temperature raising valve V1c, and the refrigerant, which is at a higher temperature than the air inside the vehicle cabin, is supplied to the air conditioner 5 through the refrigerant passage (air conditioning heating path) 13a. The refrigerant supplied to the air conditioner 5 heats the air flowing into the vehicle cabin by dissipating heat as it passes through the interior heat exchanger of the air conditioner 5, and then returns to the high-pressure compressor 1a through the refrigerant passage 15 (recovery path) and the low-pressure refrigerant switching control valve V4c, where it is compressed again.

[0032] In this embodiment, the battery 6 includes a battery case 6a and cells 6b housed inside the battery case 6a. The battery case 6a is sealed, and the refrigerant flows between the inside and outside of the battery case 6a only via the injector V2b and the refrigerant passage 18. The common rail V2a and the injector V2b form an expansion valve (second expansion valve) that expands the refrigerant and injects it into the battery case 6a.

[0033] When cooling the air conditioner 5 and the battery 6, the refrigerant used to cool the air conditioner 5 is supplied to the common rail V2a via the refrigerant passage 16, the low-pressure refrigerant switching control valve V4a, and the refrigerant passage 17 (first battery cooling path). The refrigerant stored in the common rail V2a is injected into the battery case 6a by the injector V2b under the control of the control device 40 (described later). At this time, the refrigerant expands and becomes cooler than the cells 6b. The refrigerant injected into the battery case 6a absorbs heat as it flows around the cells 6b, cooling them, and then exits the battery case 6a through the refrigerant passage 18. In this way, the cells 6b are directly cooled by the refrigerant. The refrigerant is then compressed by the low-pressure compressor 1b and returns to the high-pressure compressor 1a via the heat exchanger bypass control valve V3a, the refrigerant passage 20, the heat exchanger bypass control valve V3b, the low-pressure refrigerant switching control valve V4b, the refrigerant passage (recovery path) 22, and the low-pressure refrigerant switching control valve V4c, where it is compressed again.

[0034] Furthermore, when the air conditioner 5 is heating or stopped and the battery 6 is cooling, no refrigerant is supplied from the air conditioner 5. In this case, the refrigerant is compressed by the low-pressure compressor 1b, passes through the heat exchanger bypass control valve V3a and refrigerant passage 19, passes through the second heat exchanger 2b, is cooled, and is then supplied to the common rail V2a via the heat exchanger bypass control valve V3b, the low-pressure refrigerant switching control valve V4b, refrigerant passage 21, the low-pressure refrigerant switching control valve V4a, and refrigerant passage 17 (second battery cooling path). The refrigerant stored in the common rail V2a is injected into the battery case 6a by the injector V2b, absorbs heat as it flows around the cells 6b, thereby cooling the cells 6b, and returns to the low-pressure compressor 1b through the refrigerant passage 18, where it is compressed again.

[0035] Furthermore, no refrigerant is supplied from the air conditioner 5 when the battery 6 is heated. In this case, the refrigerant is compressed by the low-pressure compressor 1b and supplied to the common rail V2a via the heat exchanger bypass control valve V3a, refrigerant passage 20, the heat exchanger bypass control valve V3b, the low-pressure refrigerant switching control valve V4b, refrigerant passage 21, the low-pressure refrigerant switching control valve V4a, and refrigerant passage 17 (battery heating path). The refrigerant stored under pressure in the common rail V2a is injected into the battery case 6a by the injector V2b. At this time, the refrigerant expands but reaches a temperature higher than that of the cells 6b. The refrigerant injected into the battery case 6a heats the cells 6b by dissipating heat as it flows around the cells 6b, then returns to the low-pressure compressor 1b through the refrigerant passage 18 and is compressed again. In this way, the cells 6b are directly heated by the refrigerant.

[0036] Next, the electrical configuration of the temperature adjustment system 100 according to this embodiment will be described with reference to Figures 2 and 3. Figure 3 is a block diagram showing the electrical configuration of the temperature adjustment system 100 according to this embodiment.

[0037] 3, the temperature adjustment system 100 has a control device 40 configured to perform various controls in the system. The control device 40 is configured by a computer including one or more processors 40a (typically a CPU) and memory 40b such as ROM and RAM that stores various programs (including basic control programs such as an OS and application programs that are started on the OS and realize specific functions) that are interpreted and executed on the processor 40a, and various data.

[0038] The temperature adjustment system 100 also includes a refrigerant temperature sensor 31 that detects the temperature of the refrigerant flowing through the refrigerant passages 11-22, a refrigerant pressure sensor 32 that detects the pressure of the refrigerant, a battery temperature sensor 33 that detects the temperature of the battery 6, a motor temperature sensor 34 that detects the temperature of the motor 4, an inside / outside air temperature sensor 35 that detects the air temperatures inside and outside the vehicle interior of the electric vehicle 200, and an air conditioning switch 36 that receives operation input to the air conditioner 5. A plurality of refrigerant temperature sensors 31 and refrigerant pressure sensors 32 can be provided at any location in the refrigerant passages 11-22.

[0039] Based on signals input from the above-mentioned sensors 31 to 35 and the air conditioning switch 36, the control device 40 outputs control signals to the high-pressure compressor 1a, the low-pressure compressor 1b, the injector V2b, the cooling expansion valves V1a and V1b, the heating valve V1c, the heat exchanger bypass control valves V3a and V3b, and the low-pressure refrigerant switching control valves V4a, V4b, and V4c, thereby controlling them.

[0040] [control] Next, the control performed by the control device 40 in this embodiment will be described with reference to Figures 4 and 5. Figure 4 is a flowchart of the control performed by the temperature adjustment system 100 of the electric vehicle 200 according to the embodiment of the present invention, and Figure 5 is a table showing air conditioning / battery cooperative control patterns according to combinations of air conditioning requests and battery temperature adjustment requests of the temperature adjustment system 100 of the electric vehicle 200.

[0041] 4 is repeatedly executed at predetermined intervals by the control device 40. Specifically, the processor 40a in the control device 40 reads out a program stored in the memory 40b and executes the program, thereby realizing the control shown in the flowchart of FIG.

[0042] When control is started, in step S1, the control device 40 acquires various information such as the detection values ​​detected by the above-mentioned sensors 31 to 35 and the operation value input to the air conditioning switch 36.

[0043] Next, in step S2, the control device 40 acquires a cooling / heating request for the air conditioner 5, i.e., a required value for the cooling capacity or heating capacity of the air conditioner 5 (e.g., the flow rate of refrigerant supplied to the air conditioner 5), based on the information acquired in step S1. For example, the required value for the cooling capacity or heating capacity of the air conditioner 5 is acquired according to the difference between the temperature set by the air conditioning switch 36 and the temperature inside the vehicle cabin.

[0044] Next, in step S3, the control device 40 acquires a cooling requirement for the motor 4, i.e., a required value of the cooling capacity for the motor 4 (e.g., the flow rate of the refrigerant supplied to the motor 4), based on the information acquired in step S1. For example, the required value of the cooling capacity for the motor 4 is acquired according to the difference between a preset reference temperature and the temperature of the motor 4 detected by the motor temperature sensor 34.

[0045] Next, in step S4, the control device 40 acquires a temperature adjustment request for the battery 6, i.e., a request for cooling or heating the battery 6, based on the information acquired in step S1. Specifically, in a situation where cooling of the battery 6 is required, such as a situation where power is supplied from the battery 6 to drive the motor 4 or a situation where regenerative power is supplied from the motor 4 to the battery 6, and a temperature rise of the battery 6 is predicted, the control device 40 acquires a required value for cooling capacity for the battery 6 (e.g., the amount of refrigerant injected from the injector V2b) according to the magnitude of the power supplied from the battery 6 or the magnitude of the regenerative power input to the battery 6. In addition, in a situation where heating of the battery 6 is required, such as a situation where the temperature of the battery 6 needs to be raised to a charging temperature higher than room temperature in order for the electric vehicle 200 to perform charging while stationary, or when the temperature of the battery 6 detected by the battery temperature sensor 33 while the electric vehicle 200 is traveling is lower than a predetermined reference temperature, the control device 40 acquires a required value for heating capacity for the battery 6 (e.g., the amount of refrigerant injected from the injector V2b).

[0046] Next, in step S5, the control device 40 determines whether or not a temperature control request for the battery 6 was received in step S4. If a temperature control request for the battery 6 is received (step S5: YES), i.e., if a required value for the cooling or heating capacity of the battery 6 is received in step S4, the process proceeds to step S6, where the control device 40 determines an air-conditioning / battery coordinated control pattern. In this embodiment, the air-conditioning / battery coordinated control pattern refers to a control pattern of the temperature control system 100 that corresponds to a combination of a cooling / heating request for the air conditioner 5 and a temperature control request for the battery 6. For example, a table of air-conditioning / battery coordinated control patterns as shown in FIG. 5 is pre-stored in the memory 40b. The contents of the control patterns 1-a, 2-a, 2-b, 3-a, 3-b, 4-a, and 4-b shown in the table of FIG. 5 will be described later. The control device 40 retrieves from the memory 40b an air-conditioning / battery coordinated control pattern that corresponds to the cooling / heating request for the air conditioner 5 received in step S2 and the temperature control request for the battery 6 received in step S4.

[0047] After the air conditioning / battery cooperative control pattern is determined in step S6, or if it is determined in step S5 in step S4 that there is no temperature control request for the battery 6 (i.e., neither cooling nor heating of the battery 6 is requested) (step S5: NO), in step S7, the control device 40 controls the refrigerant flowing through the temperature control system 100 based on the heating / cooling request for the air conditioner 5 obtained in step S2, the cooling request for the motor 4 obtained in step S3, the temperature control request for the battery 6 obtained in step S4, and, if there is a temperature control request for the battery 6, the air conditioning / battery cooperative control pattern determined in step S6 (step S7). That is, the controller 40 controls the operations of the high-pressure compressor 1a, the low-pressure compressor 1b, the injector V2b, the cooling expansion valves V1a, V1b, the heating valve V1c, the heat exchanger bypass control valves V3a, V3b, and the low-pressure refrigerant switching control valves V4a, V4b, V4c so as to correspond to the required cooling or heating capacity of the air conditioner 5, the required cooling capacity of the motor 4, the required cooling or heating capacity of the battery 6, and the air conditioning / battery coordinated control pattern. After step S7, the controller 40 ends the control.

[0048] Next, the contents of each of the control patterns 1-a, 2-a, 2-b, 3-a, 3-b, 4-a, and 4-b shown in the table of Fig. 5 will be described with reference to Fig. 6 to Fig. 12. The upper parts of Fig. 6 to Fig. 12 show PH diagrams and PT diagrams of the cooling or heating cycle of the air conditioner 5 and battery 6 in each control pattern, and the lower parts show the heat cycle circuits of the temperature adjustment system 100 in each control pattern. In the heat cycle circuits of Fig. 6 to Fig. 12, solid lines indicate refrigerant passages through which refrigerant flows, and dashed lines indicate refrigerant passages through which refrigerant does not flow.

[0049] [Air conditioning and battery coordinated control pattern 1-a] Fig. 6 is an explanatory diagram showing the PH diagram and PT diagram of the cooling cycle of the air conditioner 5 and battery 6 in the air conditioning / battery cooperative control pattern 1-a, and the flow of refrigerant. As shown in Fig. 5, the air conditioning / battery cooperative control pattern 1-a is an example of a control pattern when there is a request for cooling of the air conditioner 5 and a request for cooling of the battery 6.

[0050] In the air conditioning / battery cooperative control pattern 1-a, as shown in FIG. 6, a heat cycle circuit for cooling the motor 4, a heat cycle circuit for cooling by the air conditioner 5, and a heat cycle circuit for cooling the battery 6 using the refrigerant after cooling the air conditioner 5 are formed in the temperature control system 100.

[0051] Of these, in the heat cycle circuit that cools the motor 4, the refrigerant is compressed by the high-pressure compressor 1a to a high temperature and high pressure (approximately 120°C, 11 MPa in the example of FIG. 6), passes through the first heat exchanger 2a via refrigerant passage 11, is cooled (approximately 30°C in the example of FIG. 6), and is further isenthalpily expanded by the cooling expansion valve V1a to a low temperature (approximately 20°C, 5 MPa in the example of FIG. 6) before being supplied to the motor 4 through refrigerant passage (motor cooling path) 12. The refrigerant supplied to the motor 4 cools the motor 4 by absorbing heat as it passes through the stator, rotor, bearings, etc. of the motor 4, and then returns to the high-pressure compressor 1a via refrigerant passage 14 (recovery path) and the low-pressure refrigerant switching control valve V4c, where it is compressed again.

[0052] In the heat cycle circuit that cools the air conditioner 5, the refrigerant is compressed by the high-pressure compressor 1a to a high temperature and high pressure (approximately 120°C and 11 MPa in the example of FIG. 6, point A2 on the PH and PT diagrams). The refrigerant then passes through the first heat exchanger 2a via the refrigerant passage 11, where it is cooled (approximately 30°C in the example of FIG. 6, point A3 on the PH and PT diagrams). The refrigerant is then isoenthalpily expanded by the cooling expansion valve V1b to a low temperature (approximately 20°C and 5 MPa in the example of FIG. 6, point A4 on the PH and PT diagrams), and is then supplied to the air conditioner 5 via the refrigerant passage (motor cooling path) 13b. The refrigerant supplied to the air conditioner 5 absorbs heat as it passes through the passenger compartment heat exchanger of the air conditioner 5, thereby cooling the air flowing into the passenger compartment. The refrigerant then returns to the high-pressure compressor 1a via the refrigerant passage 15 (recovery path) and the low-pressure refrigerant switching control valve V4c (approximately 30°C and 5 MPa in the example of FIG. 6, point A1 on the PH and PT diagrams), where it is compressed again.

[0053] In the heat cycle circuit that cools the battery 6, the refrigerant (approximately 30°C and 5 MPa in the example of FIG. 6) used to cool the air conditioner 5 is supplied to the common rail V2a via the refrigerant passage 16, the low-pressure refrigerant switching control valve V4a, and the refrigerant passage 17 (first battery cooling path) (approximately 30°C and 5 MPa in the example of FIG. 6, and point B1 on the PH and PT diagrams). The refrigerant stored in the common rail V2a is injected into the battery case 6a by the injector V2b. At this time, the refrigerant expands and becomes colder than the cells 6b (approximately −60°C and 0.1 MPa in the example of FIG. 6, and point B2 on the PH and PT diagrams). The refrigerant injected into the battery case 6a absorbs heat as it flows around the cells 6b, thereby cooling them, and then exits the battery case 6a through the refrigerant passage 18 (approximately 20°C and 0.1 MPa in the example of FIG. 6, and point B3 on the PH and PT diagrams). The refrigerant is then compressed by the low-pressure compressor 1b, passes through the heat exchanger bypass control valve V3a, the refrigerant passage 20, the heat exchanger bypass control valve V3b, the low-pressure refrigerant switching control valve V4b, the refrigerant passage (recovery path) 22, and the low-pressure refrigerant switching control valve V4c, and returns to the high-pressure compressor 1a, where it is compressed again (in the example of Figure 6, the pressure is approximately 120°C and 11 MPa, and this is point B4 on the PH diagram and the PT diagram).

[0054] [Air conditioning and battery coordinated control pattern 2-a] 7 is an explanatory diagram showing the PH diagram and PT diagram of the heating cycle of the air conditioner 5 and the cooling cycle of the battery 6 in the air conditioning / battery cooperative control pattern 2-a, and the flow of the refrigerant. As shown in FIG. 5, the air conditioning / battery cooperative control pattern 2-a is an example of a control pattern when there is a request for heating of the air conditioner 5 and a request for cooling of the battery 6.

[0055] 7, in the air conditioning / battery cooperative control pattern 2-a, the temperature adjustment system 100 forms a heat cycle circuit that cools the motor 4, a heat cycle circuit that performs heating using the air conditioner 5, and a heat cycle circuit that cools the battery 6 independently of the air conditioner 5. Of these, the heat cycle circuit that cools the motor 4 is the same as in the air conditioning / battery cooperative control pattern 1-a.

[0056] In the heat cycle circuit that heats the air conditioner 5, the refrigerant is compressed by the high-pressure compressor 1a to a high temperature and pressure (approximately 120°C and 11 MPa in the example of FIG. 7, point A2 on the PH and PT diagrams), and is expanded by the temperature raising valve V1c. The refrigerant, which is hotter than the air in the passenger compartment (approximately 60°C and 5 MPa in the example of FIG. 7, point A3 on the PH and PT diagrams), is supplied to the air conditioner 5 through the refrigerant passage (air conditioning heating path) 13a. The refrigerant supplied to the air conditioner 5 heats the air flowing into the passenger compartment by dissipating heat as it passes through the passenger compartment heat exchanger of the air conditioner 5, and then returns to the high-pressure compressor 1a through the refrigerant passage 15 (recovery path) and the low-pressure refrigerant switching control valve V4c (approximately 30°C and 5 MPa in the example of FIG. 7, point A1 on the PH and PT diagrams), where it is compressed again.

[0057] In the heat cycle circuit that cools the battery 6, the refrigerant is compressed by the low-pressure compressor 1b to a high temperature and high pressure (approximately 80°C and 2 MPa in the example of FIG. 7, point B3 on the PH and PT diagrams), passes through the heat exchanger bypass control valve V3a and refrigerant passage 19, passes through the second heat exchanger 2b, and is cooled (approximately 30°C and 2 MPa in the example of FIG. 7, point B4 on the PH and PT diagrams), and is further supplied to the common rail V2a via the heat exchanger bypass control valve V3b, the low-pressure refrigerant switching control valve V4b, refrigerant passage 21, the low-pressure refrigerant switching control valve V4a, and refrigerant passage 17 (second battery cooling path). The refrigerant stored in the common rail V2a is injected into the battery case 6a by the injector V2b. At this time, the refrigerant expands and becomes cooler than the cells 6b (in the example of FIG. 7, approximately 20°C, 0.1 MPa, point B1 on the PH and PT diagrams), and the refrigerant injected into the inside of the battery case 6a cools the cells 6b by absorbing heat as it flows around the cells 6b, and then passes through the refrigerant passage 18 and exits the battery case 6a (in the example of FIG. 7, approximately 60°C, 0.1 MPa, point B2 on the PH and PT diagrams). The refrigerant then returns to the low-pressure compressor 1b and is compressed again.

[0058] [Air conditioning and battery coordinated control pattern 2-b] 8 is an explanatory diagram showing the PH diagram and PT diagram of the heating cycle of the air conditioner 5 and battery 6 and the flow of refrigerant in the air conditioning / battery cooperative control pattern 2-b. As shown in FIG. 5, the air conditioning / battery cooperative control pattern 2-b is an example of a control pattern when there is a request for heating of the air conditioner 5 and a request for heating of the battery 6.

[0059] In air conditioning / battery cooperative control pattern 2-b, as shown in Fig. 8, the temperature adjustment system 100 forms a heat cycle circuit that cools the motor 4, a heat cycle circuit that performs heating using the air conditioner 5, and a heat cycle circuit that heats the battery 6 independently of the air conditioner 5. Of these, the heat cycle circuit that cools the motor 4 is the same as in air conditioning / battery cooperative control pattern 1-a, and the heat cycle circuit that performs heating using the air conditioner 5 is the same as in air conditioning / battery cooperative control pattern 2-a.

[0060] In the heat cycle circuit that heats the battery 6, the refrigerant is compressed by the low-pressure compressor 1b to a high temperature and pressure (approximately 80°C and 2 MPa in the example of FIG. 8, point B2 on the PH diagram and the PT diagram) and is supplied to the common rail V2a via the heat exchanger bypass control valve V3a, the refrigerant passage 20, the heat exchanger bypass control valve V3b, the low-pressure refrigerant switching control valve V4b, the refrigerant passage 21, the low-pressure refrigerant switching control valve V4a, and the refrigerant passage 17 (battery heating path). The refrigerant stored in the common rail V2a is injected into the battery case 6a by the injector V2b. At this time, the refrigerant expands but becomes hotter than cell 6b (in the example of Figure 8, this is approximately 60°C and 0.1 MPa, and point B3 on the PH and PT diagrams), and the refrigerant injected into the inside of battery case 6a heats cell 6b by dissipating heat as it flows around cell 6b, and returns to low-pressure compressor 1b through refrigerant passage 18 (in the example of Figure 8, this is approximately 20°C and 0.1 MPa, and point B1 on the PH and PT diagrams), where it is compressed again.

[0061] [Air conditioning and battery coordinated control pattern 3-a] 9 is an explanatory diagram showing the PH diagram and PT diagram of the cooling cycle of the battery 6 in the air conditioning / battery cooperative control pattern 3-a and the flow of the refrigerant. As shown in FIG. 5, the air conditioning / battery cooperative control pattern 3-a is an example of a control pattern when there is no request for heating or cooling from the air conditioner 5 (i.e., the air conditioner 5 is OFF) and there is a request for cooling of the battery 6.

[0062] In air conditioning / battery cooperative control pattern 3-a, as shown in Fig. 9, a heat cycle circuit that cools the motor 4 and a heat cycle circuit that cools the battery 6 independently of the air conditioner 5 are formed in the temperature adjustment system 100. Of these, the heat cycle circuit that cools the motor 4 is the same as in air conditioning / battery cooperative control pattern 1-a, and the heat cycle circuit that cools the battery 6 is the same as in air conditioning / battery cooperative control pattern 2-a.

[0063] [Air conditioning and battery coordinated control pattern 3-b] 10 is an explanatory diagram showing the PH diagram and PT diagram of the heating cycle of the battery 6 and the flow of the refrigerant in the air conditioning / battery cooperative control pattern 3-b. As shown in FIG. 5, the air conditioning / battery cooperative control pattern 3-b is an example of a control pattern when there is no request for heating / cooling from the air conditioner 5 (i.e., the air conditioner 5 is OFF) and there is a request for heating from the battery 6.

[0064] 10, in the air conditioning / battery cooperative control pattern 3-b, a heat cycle circuit that cools the motor 4 and a heat cycle circuit that heats the battery 6 independently of the air conditioner 5 are formed in the temperature adjustment system 100. Of these, the heat cycle circuit that cools the motor 4 is the same as in the air conditioning / battery cooperative control pattern 1-a, and the heat cycle circuit that heats the battery 6 is the same as in the air conditioning / battery cooperative control pattern 2-b.

[0065] [Air conditioning and battery coordinated control pattern 4-a] Fig. 11 is an explanatory diagram showing the PH diagram and PT diagram of the heating and cooling cycle of the air conditioner 5 and the cooling cycle of the battery 6, and the flow of refrigerant, in the air conditioning / battery cooperative control pattern 4-a. As shown in Fig. 5, the air conditioning / battery cooperative control pattern 4-a is an example of a control pattern when there is a request for dry heating for the air conditioner 5 and a request for cooling for the battery 6. In this embodiment, dry heating refers to an operation in which cooling and heating are performed simultaneously to heat the air in the vehicle cabin while dehumidifying it.

[0066] 11, in the air conditioning / battery cooperative control pattern 4-a, the temperature adjustment system 100 forms a heat cycle circuit that cools the motor 4, a heat cycle circuit that performs dry heating using the air conditioner 5, and a heat cycle circuit that cools the battery 6 independently of the air conditioner 5. Of these, the heat cycle circuit that cools the motor 4 is the same as in the air conditioning / battery cooperative control pattern 1-a, and the heat cycle circuit that cools the battery 6 is the same as in the air conditioning / battery cooperative control pattern 2-a.

[0067] In the heat cycle circuit that performs dry heating using the air conditioner 5, the refrigerant is compressed by the high-pressure compressor 1a to a high temperature and high pressure (approximately 120°C and 11 MPa in the example of FIG. 11, point A2 on the PH and PT diagrams). A portion of the high-temperature and high-pressure refrigerant passes through the first heat exchanger 2a via the refrigerant passage 11 to be cooled (approximately 30°C in the example of FIG. 11, point A3 on the PH and PT diagrams), and is further isenthalpily expanded by the cooling expansion valve V1b to a low temperature (approximately 20°C and 5 MPa in the example of FIG. 11, point A4 on the PH and PT diagrams) before being supplied to the air conditioner 5 through the refrigerant passage (motor cooling path) 13b. The refrigerant supplied to the air conditioner 5 absorbs heat as it passes through the dehumidifying heat exchanger of the air conditioner 5, thereby dehumidifying the air flowing into the vehicle cabin, and then returns to the high-pressure compressor 1a through the refrigerant passage 15 (recovery path) and the low-pressure refrigerant switching control valve V4c (approximately 30°C and 5 MPa in the example of FIG. 11, point A1 on the PH and PT diagrams). The portion of the high-temperature, high-pressure refrigerant that is not used for dehumidification expands through the temperature raising valve V1c (approximately 60°C and 5 MPa in the example of FIG. 11, point A5 on the PH and PT diagrams) and is supplied to the air conditioner 5 through the refrigerant passage (air conditioning heating path) 13a. The refrigerant supplied to the air conditioner 5 heats the air flowing into the passenger compartment by dissipating heat as it passes through the passenger compartment heat exchanger of the air conditioner 5, and then returns to the high-pressure compressor 1a through the refrigerant passage 15 (recovery path) and the low-pressure refrigerant switching control valve V4c (approximately 30°C and 5 MPa in the example of Figure 11, point A1 on the PH diagram and PT diagram), where it is compressed again together with the refrigerant used for dehumidification.

[0068] [Air conditioning and battery coordinated control pattern 4-b] 12 is an explanatory diagram showing the PH diagram and PT diagram of the heating and cooling cycle of the air conditioner 5 and the heating cycle of the battery 6, and the flow of refrigerant in the air conditioning / battery cooperative control pattern 4-b. As shown in FIG. 5, the air conditioning / battery cooperative control pattern 4-b is an example of a control pattern when there is a request for dry heating for the air conditioner 5 and a request for heating for the battery 6.

[0069] 12, in the air conditioning / battery cooperative control pattern 4-b, the temperature adjustment system 100 forms a thermal cycle circuit that cools the motor 4, a thermal cycle circuit that performs dry heating using the air conditioner 5, and a thermal cycle circuit that heats the battery 6 independently of the air conditioner 5. Of these, the thermal cycle circuit that cools the motor 4 is the same as in the air conditioning / battery cooperative control pattern 1-a, the thermal cycle circuit that performs dry heating using the air conditioner 5 is the same as in the air conditioning / battery cooperative control pattern 4-a, and the thermal cycle circuit that heats the battery 6 is the same as in the air conditioning / battery cooperative control pattern 2-b.

[0070] [Action and effect] Next, the effects of the temperature regulation systems for electric vehicles according to the above-described embodiment and modified examples will be described.

[0071] According to the temperature control system 100 of this embodiment, a common refrigerant containing CO2 is used to cool the air conditioner 5, the motor 4, and the battery 6, allowing the overall configuration of the temperature control system 100 to be compact. Furthermore, when cooling the air conditioner 5 and the battery 6, the refrigerant after cooling the air conditioner 5 is supplied to the common rail V2a and the injector V2b, where it is further expanded and injected from the injector V2b into the battery case 6a. This allows the cells 6b to be directly cooled by the refrigerant while maintaining the strength of the cells 6b of the battery 6 and the structure of the battery case 6a at the same level as in the conventional system. This allows the temperature of the battery 6 to be controlled with high responsiveness without increasing the weight of the battery 6 or the manufacturing cost.

[0072] Furthermore, the refrigerant compressed by the low-pressure compressor 1b after passing through the battery 6, the refrigerant that has passed through the air conditioner 5, and the refrigerant that has passed through the motor 44 can all be compressed by the high-pressure compressor 1a, so a common second compressor can be used to compress the refrigerant used to cool the air conditioner 5, the motor 4, and the battery 6, making the overall configuration of the temperature control system 100 compact.

[0073] Furthermore, the high-temperature, high-pressure refrigerant compressed by the low-pressure compressor 1b is expanded and injected into the battery case 6a from the injector V2b, thereby directly heating the cells 6b with the refrigerant. This allows for high-responsive temperature control of the battery 6 without increasing the weight or manufacturing costs of the battery 6.

[0074] Furthermore, the refrigerant that has passed through the battery 6 is compressed by the low-pressure compressor 1b and further cooled by the second heat exchanger 2b before being supplied to the common rail V2a and the injector V2b via the heat exchanger bypass control valve V3b, the low-pressure refrigerant switching control valve V4b, the refrigerant passage 21, the low-pressure refrigerant switching control valve V4a, and the refrigerant passage 17, and expanded and injected from the injector V2b into the battery case 6a. Therefore, even when the air conditioner 5 is heating or stopped and the refrigerant that has cooled the air conditioner 5 cannot be used, the cells 6b can be directly cooled by the refrigerant flowing through a heat cycle circuit independent of the air conditioner 5. This allows for highly responsive temperature control of the battery 6 without increasing the weight or manufacturing costs of the battery 6.

[0075] In addition, the required amount of refrigerant according to the heat generation amount and temperature of the battery 6 can be injected with high precision from the injector V2b into the inside of the battery case 6a at an appropriate pressure, thereby suppressing temperature fluctuations in the cells 6b of the battery 6 and reducing deterioration of the battery 6 due to thermal cycles.

[0076] Furthermore, the high-temperature, high-pressure refrigerant compressed by the high-pressure compressor 1a is supplied to the air conditioner 5 via the refrigerant passage 13a, thereby heating the air conditioner 5.

[0077] [Variations] In the above-described embodiment, when the air conditioner 5 is cooling and the battery 6 is cooling (air conditioning-battery cooperative control pattern 1-a), the refrigerant after cooling the air conditioner 5 is supplied to the common rail V2a and injected into the battery case 6a by the injector V2b. When the air conditioner 5 is heating or stopped and the battery 6 is cooling (air conditioning-battery cooperative control patterns 2-a, 3-a, and 4-a), the refrigerant circulates in a heat cycle circuit that cools the battery 6 independently of the air conditioner 5. However, the temperature control system 100 may be configured differently. For example, when cooling the battery 6, regardless of the air conditioning request for the air conditioner 5, the refrigerant may be compressed by the high-pressure compressor 1a, cooled through the first heat exchanger 2a, and further isenthalpily expanded by the cooling expansion valve V1b to a low temperature (e.g., approximately 20°C, 5 MPa), supplied to the common rail V2a, injected into the battery case 6a by the injector V2b, expanded to, for example, 0.1 MPa, and cooled the cells 6b. In this case, a refrigerant passage may be formed on the outside of the battery case 6a (typically on the surface of the case), and high-temperature, high-pressure refrigerant (for example, approximately 120°C, 11 MPa) compressed by the high-pressure compressor 1a may be passed through the refrigerant passage, thereby indirectly heating the cells 6b in the battery case 6a with the refrigerant. [Explanation of symbols]

[0078] 1 Compressor 1a High-pressure compressor 1b Low-pressure compressor 2 Heat exchanger 2a 1st heat exchanger 2b Second heat exchanger 4 motors 5. Air Conditioning 6 Battery 6a Battery Case 6b Cell 11~22 Refrigerant passage 31 Refrigerant temperature sensor 32 Refrigerant pressure sensor 33 Battery Temperature Sensor 34 Motor temperature sensor 35 Inside and outside air temperature sensor 36 Air conditioning switch 40 Control device 100 Temperature Control System 200 Electric Vehicles V1a, V1b cooling expansion valve V1c temperature rise valve V2a common rail V2b Injector V3a, V3b Heat exchanger bypass control valve V4a, V4b, V4c Low pressure refrigerant switching control valve

Claims

1. A temperature control system for an electric vehicle including an air conditioning unit for performing air conditioning, a drive motor, and a battery having cells housed inside a battery case, CO 2 a compressor for compressing a refrigerant including a first heat exchanger that cools the refrigerant compressed by the compressor; a first expansion valve that expands the refrigerant cooled by the first heat exchanger; an air conditioning cooling path that supplies the refrigerant expanded by the first expansion valve to the air conditioning unit when cooling the air conditioning unit; a motor cooling path that supplies the refrigerant expanded by the first expansion valve to the motor when cooling the motor; a second expansion valve that expands the refrigerant and injects it into the battery case; a first battery cooling path that supplies the refrigerant after cooling the air conditioning unit to the second expansion valve when cooling the air conditioning unit and the battery; a recovery path that supplies the refrigerant that has passed through the air conditioning unit, the refrigerant that has passed through the motor, and the refrigerant that has passed through the battery to the compressor; A temperature control system for an electric vehicle.

2. The compressor is a first compressor that compresses the refrigerant that has passed through the battery; a second compressor that compresses the refrigerant that has passed through the air conditioning unit and the refrigerant that has passed through the motor, The temperature control system for an electric vehicle according to claim 1 , wherein the second compressor further compresses the refrigerant compressed by the first compressor when cooling the air conditioning unit and the battery.

3. The temperature regulation system for an electric vehicle according to claim 2 , further comprising a battery heating path that supplies the refrigerant compressed by the first compressor to the second expansion valve when the battery is heated.

4. a second heat exchanger that cools the refrigerant compressed by the first compressor when the air conditioning unit is heating or stopped and when the battery is cooling; a second battery cooling path that supplies the refrigerant cooled by the second heat exchanger to the second expansion valve when the air conditioning unit is heating or stopped and when the battery is cooling. The temperature control system for an electric vehicle according to claim 2 or 3.

5. 4. The temperature control system for an electric vehicle according to claim 1, wherein the second expansion valve has a common rail that stores the refrigerant, and an injector that injects the refrigerant stored in the common rail into the battery case.

6. The temperature control system for an electric vehicle according to claim 1 , further comprising an air conditioning heating path that supplies the refrigerant compressed by the compressor to the air conditioning unit when the air conditioning unit is heating.

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