Thermal Management System, Thermal Management Method and Electric Vehicle

Abstract

The present application provides a thermal management system, a thermal management method, and an electric vehicle. The thermal management system includes an air-conditioning refrigerant circuit and a secondary refrigerant circuit. The air-conditioning refrigerant circuit includes a first heat exchanger and an intermediate heat exchanger. The secondary refrigerant circuit includes a secondary refrigerant heat exchange pipeline, a regulating branch, a battery branch, a motor branch, and an outside-vehicle branch. The outside-vehicle branch includes a first pipeline and a second pipeline connected in parallel. The secondary refrigerant heat exchange pipeline is heat-exchange connected to the first heat exchanger. An outside-vehicle heat exchanger is provided on the first pipeline. The first end of the secondary refrigerant heat exchange pipeline can be selectively communicated with the first end of the first pipeline or the second pipeline. The second end of the secondary refrigerant heat exchange pipeline can be selectively communicated with the first end of the regulating branch or the motor branch. The second ends of the regulating branch, the battery branch, the motor branch, and the outside-vehicle branch are connected through a first four-way valve. According to the thermal management system of the present application, the thermal energy of the whole vehicle can be reasonably distributed, the energy utilization rate of the whole vehicle can be improved, and the cruising range can be increased.

Description

Technical Field

[0001] The present application relates to the technical field of electric vehicles, and particularly relates to a thermal management system, a thermal management method, and an electric vehicle. Background Art

[0002] Pure electric vehicles are green and environmentally friendly, have low usage costs, and good market prospects, and are favored by many enterprises. At present, the problem of pure electric vehicles is the short driving range. The fundamental reason is that the working temperature of the battery affects the charge and discharge capacity and life of the battery. Especially under low temperature conditions, the performance decays severely and cannot output enough power to drive the motor to work normally. At the same time, the temperature of the drive motor cannot be too high. If the internal temperature of the motor is too high, it will cause the motor efficiency to decline. In severe cases, it will cause the coil inside the motor to burn out or even cause the coil to short circuit, resulting in motor damage. On the other hand, the heating capacity of the vehicle air conditioner in the form of an air source heat pump will also decrease as the ambient temperature drops. Therefore, there is an urgent need to develop a set of efficient vehicle thermal management systems that can reasonably distribute the vehicle's thermal energy, improve the vehicle's energy utilization rate, and increase the driving range. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present application is to provide a thermal management system, a thermal management method, and an electric vehicle that can reasonably distribute the vehicle's thermal energy, improve the vehicle's energy utilization rate, and increase the driving range.

[0004] To solve the above problems, the present application provides a thermal management system, including an air-conditioning refrigerant circuit and a secondary refrigerant circuit. The air-conditioning refrigerant circuit includes a first heat exchanger and an intermediate heat exchanger. The secondary refrigerant circuit includes a secondary refrigerant heat exchange pipeline, an adjustment branch, a battery branch, a motor branch, and an outside vehicle branch. The outside vehicle branch includes a first pipeline and a second pipeline connected in parallel. The secondary refrigerant heat exchange pipeline is heat exchange-connected to the first heat exchanger. An outside vehicle heat exchanger is provided on the first pipeline. The first end of the secondary refrigerant heat exchange pipeline can be selectively connected to the first end of the first pipeline or the second pipeline through a first three-way valve. The second end of the secondary refrigerant heat exchange pipeline can be selectively connected to the first end of the adjustment branch or the motor branch through a second three-way valve. The second ends of the adjustment branch, the battery branch, the motor branch, and the outside vehicle branch are connected through a first four-way valve. A heat exchange branch is connected between the adjustment branch and the battery branch. The heat exchange branch is heat exchange-connected to the intermediate heat exchanger.

[0005] Preferably, a first pump is provided on the adjustment branch. The heat exchange branch is connected to the pipeline between the second three-way valve and the first pump.

[0006] Preferably, a motor controller and / or a motor is provided on the motor branch. A second pump is provided on the pipeline where the motor controller and / or the motor is connected to the first four-way valve.

[0007] Preferably, a battery assembly is provided on the battery branch, and the heat exchange branch is connected to one end of the battery assembly away from the first four-way valve.

[0008] A first two-way valve is provided on the pipeline where one end of the battery assembly away from the first four-way valve communicates with the second three-way valve; and / or, a second two-way valve is provided on the heat exchange branch.

[0009] Preferably, the external branch of the vehicle further includes an expansion tank. The first pipeline and the second pipeline are connected in parallel and then connected to the first four-way valve. The expansion tank is provided on the pipeline between the parallel pipelines and the first four-way valve.

[0010] Preferably, the air-conditioning refrigerant circuit further includes a compressor and a second four-way valve. The compressor, the first heat exchanger, and the intermediate heat exchanger are connected to the second four-way valve.

[0011] Preferably, the air-conditioning refrigerant circuit further includes a second heat exchanger. The second heat exchanger is connected in parallel with the intermediate heat exchanger. A first electronic expansion valve is provided on the branch where the second heat exchanger is located, and a second electronic expansion valve is provided on the branch where the intermediate heat exchanger is located.

[0012] Preferably, a gas-liquid separator is provided at the suction end of the compressor.

[0013] Preferably, when the air-conditioning refrigerant circuit is in the cooling state, the flow direction of the refrigerant in the intermediate heat exchanger is the same as the flow direction of the coolant. When the air-conditioning refrigerant circuit is in the heating state, the flow direction of the refrigerant in the intermediate heat exchanger is opposite to the flow direction of the coolant.

[0014] According to another aspect of the present application, an electric vehicle is provided, including a thermal management system, and the thermal management system is the above-mentioned thermal management system.

[0015] According to another aspect of the present application, a thermal management method for the above-mentioned thermal management system is provided, including:

[0016] Detect the battery temperature;

[0017] Compare the detected battery temperature with the preset battery temperature;

[0018] Select the thermal management mode of the thermal management system according to the comparison result.

[0019] Preferably, the step of selecting the thermal management mode of the thermal management system according to the comparison result includes:

[0020] When the battery temperature is higher than the upper limit of the preset battery temperature, control the air-conditioning refrigerant circuit to be in the cooling mode;

[0021] Control the first three-way valve to connect the first pipeline, control the second three-way valve to connect the motor branch, control the intermediate heat exchanger to connect with the battery branch, and control the battery branch to disconnect from the motor branch;

[0022] Control the first four-way valve so that the regulating branch is connected to the battery branch and the motor branch is connected to the outside-vehicle branch;

[0023] When the battery temperature is lower than the lower limit of the preset battery temperature, control the air-conditioning refrigerant circuit to be in the heating mode;

[0024] Control the first three-way valve to connect to the first pipeline, control the second three-way valve to connect to the motor branch, control the intermediate heat exchanger to be connected to the battery branch, and control the battery branch to be disconnected from the motor branch;

[0025] Control the first four-way valve so that the regulating branch is connected to the battery branch and the motor branch is connected to the outside-vehicle branch.

[0026] Preferably, the steps of selecting the heat management mode of the heat management system according to the comparison result include:

[0027] When the battery temperature is higher than the upper limit of the preset battery temperature, control the air-conditioning refrigerant circuit to be in the cooling mode;

[0028] Control the first three-way valve to connect to the second pipeline, control the second three-way valve to connect to the motor branch, control the intermediate heat exchanger to be connected to the battery branch, and control the battery branch to be disconnected from the motor branch;

[0029] Control the first four-way valve so that the regulating branch is connected to the battery branch and the motor branch is connected to the outside-vehicle branch;

[0030] When the battery temperature is lower than the lower limit of the preset battery temperature, control the air-conditioning refrigerant circuit to be in the heating mode;

[0031] Control the first three-way valve to connect to the second pipeline, control the second three-way valve to connect to the motor branch, control the intermediate heat exchanger to be connected to the battery branch, and control the battery branch to be disconnected from the motor branch;

[0032] Control the first four-way valve so that the regulating branch is connected to the battery branch and the motor branch is connected to the outside-vehicle branch.

[0033] Preferably, the steps of selecting the heat management mode of the heat management system according to the comparison result include:

[0034] When the battery temperature is higher than the upper limit of the preset battery temperature, control the first three-way valve to connect to the first pipeline, control the second three-way valve to connect to the regulating branch, control the intermediate heat exchanger to be disconnected from the battery branch, and control the battery branch to be connected to the motor branch;

[0035] Control the first four-way valve so that the regulating branch is connected to the battery branch and the motor branch is connected to the outside-vehicle branch.

[0036] Preferably, the steps of selecting the heat management mode of the heat management system according to the comparison result include:

[0037] When the battery temperature is higher than the preset upper limit of the battery temperature, control the first three-way valve to connect to the second pipeline, control the second three-way valve to connect to the regulating branch, control the intermediate heat exchanger to disconnect from the battery branch, and control the battery branch to connect to the motor branch;

[0038] Control the first four-way valve so that the regulating branch is connected to the battery branch and the motor branch is connected to the outside vehicle branch.

[0039] Preferably, the steps of selecting the heat management mode of the heat management system according to the comparison result include:

[0040] When the battery temperature is lower than the preset lower limit of the battery temperature, control the first three-way valve to connect to the first pipeline, control the second three-way valve to connect to the regulating branch, control the intermediate heat exchanger to disconnect from the battery branch, and control the battery branch to connect to the motor branch;

[0041] Control the first four-way valve so that the regulating branch is connected to the outside vehicle branch and the motor branch is connected to the battery branch.

[0042] The heat management system provided by the present application includes an air-conditioning refrigerant circuit and a secondary refrigerant circuit. The air-conditioning refrigerant circuit includes a first heat exchanger and an intermediate heat exchanger. The secondary refrigerant circuit includes a secondary refrigerant heat exchange pipeline, a regulating branch, a battery branch, a motor branch, and an outside vehicle branch. The outside vehicle branch includes a first pipeline and a second pipeline connected in parallel. The secondary refrigerant heat exchange pipeline is heat-exchange connected to the first heat exchanger. An outside vehicle heat exchanger is provided on the first pipeline. The first end of the secondary refrigerant heat exchange pipeline can be selectively connected to the first end of the first pipeline or the second pipeline through the first three-way valve. The second end of the secondary refrigerant heat exchange pipeline can be selectively connected to the first end of the regulating branch or the motor branch through the second three-way valve. The second ends of the regulating branch, the battery branch, the motor branch, and the outside vehicle branch are connected through the first four-way valve. The regulating branch and the battery branch are connected through a heat exchange branch, and the heat exchange branch is heat-exchange connected to the intermediate heat exchanger. The heat management system of the present application can integrate the air-conditioning system, the battery thermal management system, and the drive motor cooling system into a complete set of vehicle heat management systems, realize the temperature control of the carriage, battery components, motor, etc., make full use of and reasonably distribute the heat of each part, keep the operating temperatures of the battery system and the motor system within the operating temperature range, make the heat distribution of the vehicle more effective, make the energy utilization more reasonable, can effectively realize the heat management of the whole vehicle, improve the energy utilization rate of the whole vehicle, and increase the cruising range. Description of the Drawings

[0043] Figure 1 It is the circulation structure diagram of the heat management system according to the embodiment of the present application;

[0044] Figure 2 It is the first heat management mode diagram of the heat management system according to the embodiment of the present application;

[0045] Figure 3 This is the second heat management mode diagram of the heat management system according to the embodiment of the present application;

[0046] Figure 4 This is the third heat management mode diagram of the heat management system according to the embodiment of the present application;

[0047] Figure 5 This is the fourth heat management mode diagram of the heat management system according to the embodiment of the present application;

[0048] Figure 6 This is the fifth heat management mode diagram of the heat management system according to the embodiment of the present application.

[0049] The reference numerals are shown as:

[0050] 1. First heat exchanger; 2. Intermediate heat exchanger; 3. First pipeline; 4. Second pipeline; 5. Out-of-vehicle heat exchanger; 6. First three-way valve; 7. Second three-way valve; 8. First four-way valve; 9. First pump; 10. Second pump; 11. Motor; 12. Motor controller; 13. Battery assembly; 14. First two-way valve; 15. Second two-way valve; 16. Expansion tank; 17. Compressor; 18. Second four-way valve; 19. Second heat exchanger; 20. First electronic expansion valve; 21. Second electronic expansion valve; 22. Gas-liquid separator. Detailed implementation manners

[0051] With reference to Figures 1 to 6 As shown, according to the embodiment of the present application, the heat management system includes an air-conditioning refrigerant circuit and a secondary refrigerant circuit. The air-conditioning refrigerant circuit includes a first heat exchanger 1 and an intermediate heat exchanger 2. The secondary refrigerant circuit includes a secondary refrigerant heat exchange pipeline, a regulating branch, a battery branch, a motor branch, and an out-of-vehicle branch. The out-of-vehicle branch includes a first pipeline 3 and a second pipeline 4 connected in parallel. The secondary refrigerant heat exchange pipeline is heat exchange-connected to the first heat exchanger 1. An out-of-vehicle heat exchanger 5 is provided on the first pipeline 3. The first end of the secondary refrigerant heat exchange pipeline can be selectively communicated with the first end of the first pipeline 3 or the second pipeline 4 through a first three-way valve 6. The second end of the secondary refrigerant heat exchange pipeline can be selectively communicated with the first end of the regulating branch or the motor branch through a second three-way valve 7. The second ends of the regulating branch, the battery branch, the motor branch, and the out-of-vehicle branch are connected through a first four-way valve 8. A heat exchange branch is connected between the regulating branch and the battery branch, and the heat exchange branch is heat exchange-connected to the intermediate heat exchanger 2.

[0052] The thermal management system of the present application can integrate the air conditioning system, the battery thermal management system, and the drive motor cooling system into a complete set of vehicle thermal management systems, realizing temperature control of the passenger compartment, battery components, motors, etc., making full use of and reasonably distributing the heat of each part, keeping the operating temperatures of the battery system and the motor system within the operating temperature range, making the vehicle heat distribution more effective, the energy utilization more reasonable, effectively realizing the heat management of the whole vehicle, improving the energy utilization rate of the whole vehicle, and increasing the cruising range.

[0053] A first pump 9 is provided on the regulating branch, and the heat exchange branch is connected to the pipeline between the second three-way valve 7 and the first pump 9. In this embodiment, by adding the first pump 9, a refrigerant circulation driving mechanism can be added to the regulating branch, and the first pump 9 is used to provide circulating power for the refrigerant on the regulating branch.

[0054] A motor controller 12 and / or a motor 11 are provided on the motor branch, and a second pump 10 is provided on the pipeline where the motor controller 12 and / or the motor 11 are connected to the first four-way valve 8. In this embodiment, the motor controller 12 and the motor 11 are connected in series on the motor branch, and the second pump 10 is located on the motor branch to provide circulating power for the refrigerant on the motor branch.

[0055] A battery component 13 is provided on the battery branch, the heat exchange branch is connected to one end of the battery component 13 away from the first four-way valve 8, and a first two-way valve 14 is provided on the pipeline where one end of the battery component 13 away from the first four-way valve 8 communicates with the second three-way valve 7; and / or, a second two-way valve 15 is provided on the heat exchange branch.

[0056] By providing the first two-way valve 14 on the battery branch, the connection state between the battery branch and the motor branch can be adjusted by controlling the on-off of the first two-way valve 14, and further the flow path of the refrigerant can be adjusted.

[0057] By providing the second two-way valve 15 on the heat exchange branch, the communication state between the heat exchange branch and the battery branch can be adjusted by controlling the on-off of the second two-way valve 15, and further the heat exchange mode of the battery branch can be adjusted. The above-mentioned first two-way valve 14 and second two-way valve 15 are both solenoid valves.

[0058] The outside vehicle branch further includes an expansion tank 16. The first pipeline 3 and the second pipeline 4 are connected in parallel and then connected to the first four-way valve 8, and the expansion tank 16 is provided on the pipeline between the parallel pipeline and the first four-way valve 8. The expansion tank 16 can improve the working stability of the refrigerant in the refrigerant circuit, stabilize the system pressure, and improve the system operation stability.

[0059] The air-conditioning refrigerant circuit further includes a compressor 17 and a second four-way valve 18. The compressor 17, the first heat exchanger 1, and the intermediate heat exchanger 2 are connected to the second four-way valve 18. The second four-way valve 18 is used to realize the regulation of the refrigerant flow direction reversal in the air-conditioning refrigerant circuit, and further realize the conversion of the refrigeration and heating working conditions of the air-conditioning refrigerant circuit.

[0060] The air-conditioning refrigerant circuit further includes a second heat exchanger 19. The second heat exchanger 19 is connected in parallel with the intermediate heat exchanger 2. A first electronic expansion valve 20 is provided on the branch where the second heat exchanger 19 is located, and a second electronic expansion valve 21 is provided on the branch where the intermediate heat exchanger 2 is located. The first electronic expansion valve 20 can control whether the second heat exchanger 19 works, and the second electronic expansion valve 21 can control whether the intermediate heat exchanger 2 works. By setting the first electronic expansion valve 20 and the second electronic expansion valve 21, the working state of the intermediate heat exchanger 2 or the second heat exchanger 19 can be adjusted without affecting the operation of other branches.

[0061] In this embodiment, the first heat exchanger 1 is the outdoor heat exchanger of the air-conditioning refrigerant circuit, and the second heat exchanger 19 is the indoor heat exchanger of the air-conditioning refrigerant circuit. The air-conditioning refrigerant circuit mainly realizes the function of adjusting the temperature inside the carriage through the second heat exchanger 19.

[0062] A gas-liquid separator 22 is provided at the suction end of the compressor 17.

[0063] When the air-conditioning refrigerant circuit is in the refrigeration state, the flow direction of the refrigerant in the intermediate heat exchanger 2 is the same as the flow direction of the coolant. When the air-conditioning refrigerant circuit is in the heating state, the flow direction of the refrigerant in the intermediate heat exchanger 2 is opposite to the flow direction of the coolant, which can make the flow direction of the refrigerant and the coolant adapt to the working conditions of the air-conditioning refrigerant circuit, thereby effectively improving the heat exchange efficiency between the refrigerant and the coolant.

[0064] The above-mentioned coolant is, for example, water or a mixed solution of water and ethylene glycol.

[0065] According to an embodiment of the present application, an electric vehicle includes a thermal management system, and this thermal management system is the above-mentioned thermal management system.

[0066] Combined with Figures 2 to 6 As shown, according to an embodiment of the present application, the thermal management method of the above-mentioned thermal management system includes: detecting the battery temperature; comparing the detected battery temperature with a preset battery temperature; and selecting a thermal management mode of the thermal management system according to the comparison result.

[0067] This application can select an appropriate thermal management mode according to the relationship between the battery temperature and the preset battery temperature, so that the heat of the vehicle compartment, battery, and motor can be managed uniformly. The heat can be redistributed and adjusted according to the different operating conditions of each component, realizing the complementary utilization of heat, the utilization of waste heat, precise temperature control, and the goal of improving the efficiency of the vehicle's thermal management system.

[0068] The air-conditioning refrigerant circuit includes a compressor 17, a first heat exchanger 1, a second heat exchanger 19, and an intermediate heat exchanger 2. The heat exchange medium of the second heat exchanger 19 is refrigerant and the air inside the vehicle compartment, and the heat exchange medium of the first heat exchanger 1 is refrigerant and the coolant. Starting from the suction port of the compressor 17, in the cooling mode, the refrigerant flow direction is: compressor 17 → second four-way valve 18 → first heat exchanger 1 → first electronic expansion valve 20 and second electronic expansion valve 21 → second heat exchanger 19 and intermediate heat exchanger 2 → second four-way valve 18 → gas-liquid separator 22 → compressor 17. In the heating mode, the refrigerant flow direction is: compressor 17 → second four-way valve 18 → second heat exchanger 19 and intermediate heat exchanger 2 → first electronic expansion valve 20 and second electronic expansion valve 21 → first heat exchanger 1 → second four-way valve 18 → gas-liquid separator 22 → compressor 17. Here, in the cooling mode and the heating mode, by controlling the opening degrees of the first electronic expansion valve 20 and the second electronic expansion valve 21, the second heat exchanger 19 and the intermediate heat exchanger 2 can operate non-simultaneously.

[0069] The coolant circuit conducts relatively independent thermal management for the battery system and the motor system. The two cycles are in parallel and there is no direct heat exchange. It can be divided into an independent battery thermal management cycle and an independent motor thermal management cycle. Among them, the independent battery thermal management cycle cools or heats the battery. Starting from the inlet of the first pump 9, the coolant flow direction is: first pump 9 → battery module 13 → intermediate heat exchanger 2 → first pump 9; the independent motor thermal management cycle cools or heats the motor 11 and the motor controller 12. Starting from the inlet of the first pump 9, the coolant flow direction is: first pump 9 → first four-way valve 8 → expansion tank 16 → external heat exchanger 5 (or bypass) → first three-way valve 6 → first heat exchanger 1 → second three-way valve 7 → motor controller 12 → motor 11 → first pump 9.

[0070] The steps of selecting the thermal management mode of the thermal management system according to the comparison result include: when the battery temperature is higher than the preset upper limit of the battery temperature, controlling the air-conditioning refrigerant circuit to be in the refrigeration mode; controlling the first three-way valve 6 to communicate with the first pipeline 3, controlling the second three-way valve 7 to communicate with the motor branch, controlling the intermediate heat exchanger 2 to communicate with the battery branch, and controlling the battery branch to be disconnected from the motor branch; controlling the first four-way valve 8 so that the regulating branch communicates with the battery branch and the motor branch communicates with the outside vehicle branch; when the battery temperature is lower than the preset lower limit of the battery temperature, controlling the air-conditioning refrigerant circuit to be in the heating mode; controlling the first three-way valve 6 to communicate with the first pipeline 3, controlling the second three-way valve 7 to communicate with the motor branch, controlling the intermediate heat exchanger 2 to communicate with the battery branch, and controlling the battery branch to be disconnected from the motor branch; controlling the first four-way valve 8 so that the regulating branch communicates with the battery branch and the motor branch communicates with the outside vehicle branch.

[0071] The thermal management of the battery assembly 13 is achieved by heat exchange between the coolant and the air-conditioning refrigerant, so as to keep the battery temperature within a reasonable range. In the first thermal management mode, if the battery temperature exceeds the upper limit of the normal operating temperature, the air conditioner operates in the refrigeration mode. In the independent battery thermal management cycle, the media flows in the same direction on both sides of the intermediate heat exchanger 2. By controlling the opening degree of the second electronic expansion valve 21 and the frequency of the first pump 9, the flow rates of the refrigerant and the coolant are adjusted respectively, so that the temperature of the coolant drops to the target value to cool the battery assembly 13. At this time, in the independent motor thermal management cycle, after the coolant releases heat through the outside vehicle heat exchanger 5, it cools the first heat exchanger 1, and then flows through the motor controller 12 and the motor 11 to cool them.

[0072] If the battery temperature is lower than the lower limit of the normal operating temperature, the air conditioner operates in the heating mode. In the independent battery thermal management cycle, the media flows in opposite directions on both sides of the intermediate heat exchanger 2. By controlling the opening degree of the second electronic expansion valve 21 and the frequency of the first pump 9, the flow rates of the refrigerant and the coolant are adjusted respectively, so that the temperature of the coolant rises to the target value to heat the battery. At this time, in the independent motor thermal management cycle, the coolant transfers the heat of the motor 11 and the motor controller 12 together with the heat absorbed from the outside vehicle air to the first heat exchanger 1 of the air conditioner, and utilizes the waste heat of the motor 11 and the motor controller 12 to improve the energy efficiency of the air conditioner.

[0073] The steps of selecting the heat management mode of the heat management system according to the comparison result include: when the battery temperature is higher than the preset upper limit of the battery temperature, controlling the air-conditioning refrigerant circuit to be in the refrigeration mode; controlling the first three-way valve 6 to communicate with the second pipeline 4, controlling the second three-way valve 7 to communicate with the motor branch, controlling the intermediate heat exchanger 2 to communicate with the battery branch, and controlling the battery branch to be disconnected from the motor branch; controlling the first four-way valve 8 so that the regulating branch communicates with the battery branch and the motor branch communicates with the outside vehicle branch; when the battery temperature is lower than the preset lower limit of the battery temperature, controlling the air-conditioning refrigerant circuit to be in the heating mode; controlling the first three-way valve 6 to communicate with the second pipeline 4, controlling the second three-way valve 7 to communicate with the motor branch, controlling the intermediate heat exchanger 2 to communicate with the battery branch, and controlling the battery branch to be disconnected from the motor branch; controlling the first four-way valve 8 so that the regulating branch communicates with the battery branch and the motor branch communicates with the outside vehicle branch.

[0074] The difference between the second heat management mode and the first heat management mode lies in the commutation of the first three-way valve 6, that is, the external circulation coolant does not pass through the outside vehicle heat exchanger 5 after coming out of the expansion tank 16, but bypasses to the first heat exchanger 1 through the second pipeline 4. This cycle is applicable to the situation where the heating demand of the carriage and the battery heating demand are small, that is, the waste heat recovery of the motor system meets the heating demand of the carriage and the battery heating demand, and there is no need to take heat from the environment anymore.

[0075] In another embodiment, the coolant circuit connects the battery assembly 13, the motor 11 and the motor controller 12 in series, and the second three-way valve 7 commutes, that is, the intermediate heat exchanger 2 does not work, and the coolant only exchanges heat with the refrigerant at the first heat exchanger 1 to maintain the normal temperature of the battery assembly 13, the carriage and the motor system. There are mainly three circulation modes in this case.

[0076] If the battery temperature exceeds the upper limit of the normal working temperature, the battery needs to be cooled. The circulation modes of the coolant system mainly adopt the third heat management mode and the fourth heat management mode. As Figure 4 、 Figure 5 shown, the flow direction of the coolant is as follows:

[0077] Starting from the inlet of the first pump 9, the flow direction of the coolant is the first pump 9 → the first four-way valve 8 → the battery assembly 13 → the first two-way valve 14 → the motor controller 12 → the motor 11 → the first pump 9 → the first four-way valve 8 → the expansion tank 16 → the outside vehicle heat exchanger 5 (or bypass) → the first three-way valve 6 → the first heat exchanger 1 → the second three-way valve 7 → the first pump 9.

[0078] In the third thermal management mode, the steps of selecting the thermal management mode of the thermal management system according to the comparison result include: when the battery temperature is higher than the preset upper limit of the battery temperature, controlling the first three-way valve 6 to connect the first pipeline 3, controlling the second three-way valve 7 to connect the regulating branch, controlling the intermediate heat exchanger 2 to disconnect from the battery branch, and controlling the battery branch to connect with the motor branch; controlling the first four-way valve 8 to connect the regulating branch with the battery branch and the motor branch with the outside vehicle branch.

[0079] In the case where the motor 11 does not work, the third thermal management mode transfers the heat generated by the battery assembly 13 and the heat of the outside vehicle environmental heat source to the first heat exchanger 1 to increase the heating capacity in the vehicle compartment for heat recovery; in addition, if the motor 11 works, the third thermal management mode transfers the heat generated by the battery assembly 13, the heat dissipated by the motor system, and the heat of the outside vehicle environmental heat source to the first heat exchanger 1 to further increase the heating capacity in the vehicle compartment. This situation is applicable to transitional seasons such as spring and autumn. The heat generated by the battery assembly 13 can also be transferred to the outside vehicle heat exchanger 5, that is, the first heat exchanger 1 does not work. This situation is applicable to charging in summer; in addition, if the motor 11 works, the heat generated by the battery assembly 13 and the heat dissipated by the motor system are transferred to the outside vehicle heat exchanger 5, that is, the first heat exchanger 1 does not work. This situation is also applicable to transitional seasons such as spring and autumn.

[0080] The third thermal management mode is also applicable to the initial stage of system debugging and the maintenance process when adding refrigerant.

[0081] In the fourth thermal management mode, the steps of selecting the thermal management mode of the thermal management system according to the comparison result include: when the battery temperature is higher than the preset upper limit of the battery temperature, controlling the first three-way valve 6 to connect the second pipeline 4, controlling the second three-way valve 7 to connect the regulating branch, controlling the intermediate heat exchanger 2 to disconnect from the battery branch, and controlling the battery branch to connect with the motor branch; controlling the first four-way valve 8 to connect the regulating branch with the battery branch and the motor branch with the outside vehicle branch.

[0082] The difference between the fourth thermal management mode and the third thermal management mode lies in the reversal of the first three-way valve 6, that is, the outside circulation refrigerant bypasses the outside vehicle heat exchanger 5 after coming out of the first three-way valve 6 and enters the battery branch through the first four-way valve 8. At this time, the refrigerant transfers the heat generated by the battery assembly 13 and the heat dissipated by the motor system to the first heat exchanger 1 to further increase the heating capacity in the vehicle compartment. This situation is applicable to the case where the heating capacity requirement in the vehicle compartment is small, that is, the waste heat recovery of the battery assembly 13 and the motor system meets the heating capacity in the vehicle compartment and there is no need to take heat from the environment anymore.

[0083] In the fifth heat management mode, the steps of selecting the heat management mode of the heat management system according to the comparison result include: when the battery temperature is lower than the lower limit of the preset battery temperature, controlling the first three-way valve 6 to connect the first pipeline 3, controlling the second three-way valve 7 to connect the regulating branch, controlling the intermediate heat exchanger 2 to disconnect from the battery branch, and controlling the battery branch to connect with the motor branch; controlling the first four-way valve 8 to connect the regulating branch with the outside vehicle branch and the motor branch with the battery branch.

[0084] If the battery temperature is lower than the lower limit of the normal operating temperature, the battery module 13 needs to be heated. The circulating mode of the coolant system mainly adopts the fifth heat management mode. As Figure 6 shown, at this time, the battery module 13, the motor 11, and the motor controller 12 form an independent loop. At this time, the battery, the motor, and the electronic control unit do not exchange heat with the vehicle compartment air-conditioning system. At this time, there are two independent coolant circulations. The coolant circulations of the battery, the motor, and the electronic control unit are as follows:

[0085] Starting from the inlet of the first pump 9, the coolant flow direction is: the first pump 9 → the first four-way valve 8 → the battery module 13 → the first two-way valve 14 → the motor controller 12 → the motor 11 → the first pump 9. At this time, the heat required by the battery is provided by the motor 11 and the motor controller 12. This situation is applicable to transitional seasons, such as spring and autumn;

[0086] Another independent circulation is: starting from the inlet of the first pump 9, the coolant flow direction is: the first pump 9 → the first four-way valve 8 → the expansion tank 16 → the outside vehicle heat exchanger 5 → the first three-way valve 6 → the first heat exchanger 1 → the second three-way valve 7 → the first pump 9. When there is a heating or cooling demand in the vehicle compartment, the air conditioner starts, and the refrigerant exchanges heat with the coolant through the first heat exchanger 1. The coolant circulation is driven by the first pump 9 to operate; when there is no heating or cooling demand in the vehicle compartment, the air conditioner shuts down, and at this time, this circulation does not start, that is, the first pump 9 does not operate.

[0087] It is easy for those skilled in the art to understand that, on the premise of no conflict, the above-mentioned various advantageous ways can be freely combined and superimposed.

[0088] The above are only the preferred embodiments of the present application, and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included in the protection scope of the present application. The above is only the preferred implementation manner of the present application. It should be noted that for those of ordinary skill in the art in this technical field, several improvements and variations can be made without departing from the technical principle of the present application, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. A thermal management system, characterized in that, it includes an air-conditioning refrigerant circuit and a secondary refrigerant circuit. The air-conditioning refrigerant circuit includes a first heat exchanger (1) and an intermediate heat exchanger (2). The secondary refrigerant circuit includes a secondary refrigerant heat exchange pipeline, a regulating branch, a battery branch, a motor branch, and an external vehicle branch. The external vehicle branch includes a first pipeline (3) and a second pipeline (4) connected in parallel. The secondary refrigerant heat exchange pipeline is heat exchange connected to the first heat exchanger (1). An external vehicle heat exchanger (5) is provided on the first pipeline (3). The first end of the secondary refrigerant heat exchange pipeline can be selectively connected to the first end of the first pipeline (3) or the second pipeline (4) through a first three-way valve (6). The second end of the secondary refrigerant heat exchange pipeline can be selectively connected to the first end of the regulating branch or the motor branch through a second three-way valve (7). The second ends of the regulating branch, the battery branch, the motor branch, and the external vehicle branch are connected through a first four-way valve (8). The regulating branch and the battery branch are connected through a heat exchange branch, and the heat exchange branch is heat exchange connected to the intermediate heat exchanger (2); a battery assembly (13) is provided on the battery branch, and the heat exchange branch is connected to one end of the battery assembly (13) away from the first four-way valve (8), a first two-way valve (14) is provided on the pipeline connecting the end of the battery assembly (13) away from the first four-way valve (8) and the second three-way valve (7); and / or, a second two-way valve (15) is provided on the heat exchange branch.

2. The thermal management system according to claim 1, characterized in that, a first pump (9) is provided on the regulating branch, and the heat exchange branch is connected to the pipeline between the second three-way valve (7) and the first pump (9).

3. The thermal management system according to claim 1, characterized in that, a motor controller (12) and / or a motor (11) is provided on the motor branch, and a second pump (10) is provided on the pipeline connecting the motor controller (12) and / or the motor (11) and the first four-way valve (8).

4. The thermal management system according to claim 1, characterized in that, the external vehicle branch further includes an expansion tank (16). After the first pipeline (3) and the second pipeline (4) are connected in parallel, they are connected to the first four-way valve (8), and the expansion tank (16) is provided on the pipeline between the parallel pipeline and the first four-way valve (8).

5. The thermal management system according to claim 1, characterized in that, the air-conditioning refrigerant circuit further includes a compressor (17) and a second four-way valve (18), and the compressor (17), the first heat exchanger (1), and the intermediate heat exchanger (2) are connected to the second four-way valve (18).

6. The thermal management system according to claim 5, characterized in that, The air-conditioning refrigerant circuit further includes a second heat exchanger (19), the second heat exchanger (19) is connected in parallel with the intermediate heat exchanger (2), a first electronic expansion valve (20) is provided on the branch where the second heat exchanger (19) is located, and a second electronic expansion valve (21) is provided on the branch where the intermediate heat exchanger (2) is located.

7. The thermal management system according to claim 5, characterized in that, a gas-liquid separator (22) is provided at the suction end of the compressor (17).

8. The thermal management system according to claim 1, characterized in that, when the air-conditioning refrigerant circuit is in the refrigeration state, the flow direction of the refrigerant in the intermediate heat exchanger (2) is the same as the flow direction of the secondary coolant, and when the air-conditioning refrigerant circuit is in the heating state, the flow direction of the refrigerant in the intermediate heat exchanger (2) is opposite to the flow direction of the secondary coolant.

9. An electric vehicle includes a thermal management system, characterized in that, the thermal management system is the thermal management system according to any one of claims 1 to 8.

10. A thermal management method for a thermal management system according to any one of claims 1 to 8, characterized in that, includes: detecting the battery temperature; comparing the detected battery temperature with a preset battery temperature; selecting a thermal management mode of the thermal management system according to the comparison result.

11. The thermal management method according to claim 10, characterized in that, the step of selecting a thermal management mode of the thermal management system according to the comparison result includes: when the battery temperature is higher than the upper limit of the preset battery temperature, controlling the air-conditioning refrigerant circuit to be in the refrigeration mode; controlling the first three-way valve (6) to communicate with the first pipeline (3), controlling the second three-way valve (7) to communicate with the motor branch, controlling the intermediate heat exchanger (2) to communicate with the battery branch, and controlling the battery branch to be disconnected from the motor branch; controlling the first four-way valve (8) so that the regulating branch communicates with the battery branch and the motor branch communicates with the outside vehicle branch; when the battery temperature is lower than the lower limit of the preset battery temperature, controlling the air-conditioning refrigerant circuit to be in the heating mode; controlling the first three-way valve (6) to communicate with the first pipeline (3), controlling the second three-way valve (7) to communicate with the motor branch, controlling the intermediate heat exchanger (2) to communicate with the battery branch, and controlling the battery branch to be disconnected from the motor branch; controlling the first four-way valve (8) so that the regulating branch communicates with the battery branch and the motor branch communicates with the outside vehicle branch.

12. The thermal management method according to claim 10, characterized in that, the step of selecting a thermal management mode of the thermal management system according to the comparison result includes: when the battery temperature is higher than the upper limit of the preset battery temperature, controlling the air-conditioning refrigerant circuit to be in the refrigeration mode; controlling the first three-way valve (6) to communicate with the second pipeline (4), controlling the second three-way valve (7) to communicate with the motor branch, controlling the intermediate heat exchanger (2) to communicate with the battery branch, and controlling the battery branch to be disconnected from the motor branch; controlling the first four-way valve (8) so that the regulating branch communicates with the battery branch and the motor branch communicates with the outside vehicle branch; when the battery temperature is lower than the lower limit of the preset battery temperature, controlling the air-conditioning refrigerant circuit to be in the heating mode; Control the first three-way valve (6) to connect to the second pipeline (4), control the second three-way valve (7) to connect to the motor branch, control the intermediate heat exchanger (2) to connect to the battery branch, and control the battery branch to disconnect from the motor branch; Control the first four-way valve (8) so that the regulating branch connects to the battery branch and the motor branch connects to the outside vehicle branch.

13. The thermal management method according to claim 10, characterized in that, The steps of selecting the thermal management mode of the thermal management system according to the comparison result include: When the battery temperature is higher than the preset upper limit of the battery temperature, control the first three-way valve (6) to connect to the first pipeline (3), control the second three-way valve (7) to connect to the regulating branch, control the intermediate heat exchanger (2) to disconnect from the battery branch, and control the battery branch to connect to the motor branch; Control the first four-way valve (8) so that the regulating branch connects to the battery branch and the motor branch connects to the outside vehicle branch.

14. The thermal management method according to claim 10, characterized in that, The steps of selecting the thermal management mode of the thermal management system according to the comparison result include: When the battery temperature is higher than the preset upper limit of the battery temperature, control the first three-way valve (6) to connect to the second pipeline (4), control the second three-way valve (7) to connect to the regulating branch, control the intermediate heat exchanger (2) to disconnect from the battery branch, and control the battery branch to connect to the motor branch; Control the first four-way valve (8) so that the regulating branch connects to the battery branch and the motor branch connects to the outside vehicle branch.

15. The thermal management method according to claim 10, characterized in that, The steps of selecting the thermal management mode of the thermal management system according to the comparison result include: When the battery temperature is lower than the preset lower limit of the battery temperature, control the first three-way valve (6) to connect to the first pipeline (3), control the second three-way valve (7) to connect to the regulating branch, control the intermediate heat exchanger (2) to disconnect from the battery branch, and control the battery branch to connect to the motor branch; Control the first four-way valve (8) so that the regulating branch connects to the outside vehicle branch and the motor branch connects to the battery branch.

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