A thermal management system, a control method, and an electric vehicle

Abstract

The present invention provides a thermal management system, a control method and an electric vehicle. The thermal management system includes: a heat pump circulation pipeline, a battery circulation pipeline and a motor circulation pipeline. A compressor, a first heat exchanger, a second heat exchanger and a battery heat exchanger are arranged on the heat pump circulation pipeline. Through the second heat exchanger, heating or cooling of the vehicle interior or the room interior can be performed. A part of the battery heat exchanger is also arranged on the battery circulation pipeline, so that the heat pump circulation pipeline and the battery circulation pipeline can exchange heat at the battery heat exchanger. A part of the first heat exchanger is also arranged on the motor circulation pipeline, so that the heat pump circulation pipeline and the motor circulation pipeline can exchange heat at the battery heat exchanger. According to the present invention, the heat pump circulation pipeline, the battery circulation pipeline and the motor circulation pipeline are effectively combined, so that the operating temperatures of the battery system and the motor system are maintained within a reasonable range, realizing the heat management of the whole vehicle and improving the energy utilization rate of the electric vehicle.

Description

Technical Field

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

[0002] The single-vehicle fuel consumption of pure electric vehicles is zero, the use cost is low, and the market prospect is good, so it is 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 seriously and it is unable to 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 lead to a decrease in motor efficiency. 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. And the automobile air conditioner has the problem of insufficient heating capacity at low temperature. The comparative document CN110525271A does not make full use of the heat dissipated by the motor. The temperature inside the vehicle is relatively low in winter, and a PTC heater is installed in the coolant circuit, resulting in low energy utilization rate and complex pipelines. It is necessary to further improve the efficiency of the thermal management system and simplify the system.

[0003] Due to the problems of low battery charge and discharge efficiency in low temperature and high temperature conditions, insufficient heating capacity of the air conditioner in low temperature conditions and low energy utilization rate in existing electric vehicles, the present invention researches and designs a thermal management system, a control method and an electric vehicle. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention mainly lies in overcoming the defect of low energy utilization rate in existing electric vehicles, so as to provide a thermal management system, a control method and an electric vehicle.

[0005] To solve the above problems, the present invention provides a thermal management system, which includes:

[0006] A heat pump circulation pipeline, a battery circulation pipeline and a motor circulation pipeline. A compressor, a first heat exchanger, a second heat exchanger and a battery heat exchanger are arranged on the heat pump circulation pipeline. Through the second heat exchanger, heating or cooling can be performed on the inside of the vehicle or the room. A part of the battery heat exchanger is also arranged on the battery circulation pipeline, so that heat exchange can be performed between the heat pump circulation pipeline and the battery circulation pipeline at the battery heat exchanger. A part of the first heat exchanger is also arranged on the motor circulation pipeline, so that heat exchange can be performed between the heat pump circulation pipeline and the motor circulation pipeline at the battery heat exchanger. A battery assembly is arranged on the battery circulation pipeline, and a motor assembly is arranged on the motor circulation pipeline;

[0007] It further includes a second four-way valve, which is arranged between the battery circulation pipeline and the motor circulation pipeline, so as to control the battery circulation pipeline and the motor circulation pipeline to be connected or disconnected by switching the second four-way valve;

[0008] It further includes a third four-way valve and a second pump, both of which are arranged on the motor circulation pipeline, so that the motor circulation pipeline can be switched between a positive circulation and a reverse circulation by switching the third four-way valve. The positive circulation means that the coolant flows in the first direction in the motor circulation pipeline, and the reverse circulation means that the coolant flows in the second direction in the motor circulation pipeline. The first direction is opposite to the second direction.

[0009] Preferably, when the battery circulation pipeline and the motor circulation pipeline are connected, they jointly form a loop, and when the battery circulation pipeline and the motor circulation pipeline are not connected, they respectively form closed loops.

[0010] Preferably, the second four-way valve includes a first end, a second end, a third end and a fourth end. The first end and the second end are respectively connected to the battery circulation pipeline, so that when the first end and the second end are connected, and the third end and the fourth end are connected, the battery circulation pipeline forms a loop. When the first end and the fourth end are connected, and the second end and the third end are connected, the battery circulation pipeline and the motor circulation pipeline jointly form a loop.

[0011] Preferably, the third four-way valve includes a fifth end, a sixth end, a seventh end and an eighth end. The fifth end is connected to the outlet end of the second pump, the sixth end is connected to the fourth end of the second four-way valve, the seventh end is connected to the inlet end of the second pump, and the eighth end is connected to one end of the motor assembly.

[0012] Preferably, the battery heat exchanger is arranged in parallel with the second heat exchanger; and / or, a first pump is arranged on the battery circulation pipeline; and / or, the motor assembly includes a charger, a motor controller and a motor connected in series; and / or, a first four-way valve is further arranged at the exhaust end of the compressor on the heat pump circulation pipeline; and / or, a gas-liquid separator is further arranged at the suction end of the compressor on the heat pump circulation pipeline.

[0013] Preferably, on the heat pump circulation pipeline, the pipe section where the second heat exchanger is located is the first pipe section, the pipe section where the battery heat exchanger is located on the heat pump circulation pipeline is the second pipe section, the first pipe section and the second pipe section are connected in parallel, and a first throttling device is provided on the first pipe section, and a second throttling device is provided on the second pipe section.

[0014] Preferably, the first pump is a water pump; and / or, the second pump is a water pump; and / or, an expansion tank is further provided on the motor circulation pipeline.

[0015] Preferably, a first branch is further provided in parallel at the pipe section of the motor circulation pipeline and located between the second four-way valve and the first heat exchanger. An external vehicle heat exchanger is provided on the first branch, and a three-way valve is further provided at the position where the first branch is connected to the motor circulation pipeline.

[0016] The present invention further provides a control method for the heat management system as described in any one of the preceding items, wherein:

[0017] When including the first four-way valve, the second four-way valve, the first throttling device and the second throttling device:

[0018] When the ambient temperature T 环 <T 预设1 , and when the battery assembly needs to be heated and heating is required inside the vehicle or indoors, control the first four-way valve to connect the battery heat exchanger to the exhaust end of the compressor, and at the same time control the second four-way valve to disconnect the battery circulation pipeline and the motor circulation pipeline. The battery circulation pipeline and the motor circulation pipeline respectively form closed loops, and control both the first throttling device and the second throttling device to be opened;

[0019] When the ambient temperature T 环 >T 预设2 , and when the battery assembly needs to be cooled and cooling is required inside the vehicle or indoors, control the first four-way valve to connect the battery heat exchanger to the suction end of the compressor, and at the same time control the second four-way valve to disconnect the battery circulation pipeline and the motor circulation pipeline. The battery circulation pipeline and the motor circulation pipeline respectively form closed loops, and control both the first throttling device and the second throttling device to be opened;

[0020] When the ambient temperature T 预设1 <T 环 <T 预设2and when the battery assembly needs to be cooled, control the second four-way valve to connect the battery circulation pipeline and the motor circulation pipeline, so that the battery circulation pipeline and the motor circulation pipeline jointly form a loop, and when an external heat exchanger is included, the coolant in the motor circulation pipeline releases heat in the first heat exchanger and / or in the external heat exchanger, and control the first throttling device to open and control the second throttling device to close;

[0021] When the ambient temperature T 预设1 <T 环 <T 预设2 and when the battery assembly needs to be heated, control the second four-way valve to connect the battery circulation pipeline and the motor circulation pipeline, so that the battery circulation pipeline and the motor circulation pipeline jointly form a loop, and when an external heat exchanger is included, the coolant in the motor circulation pipeline absorbs heat in the first heat exchanger, and / or absorbs heat in the external heat exchanger, and / or absorbs heat in the motor assembly, and control the first throttling device to open and control the second throttling device to close;

[0022] wherein, T 预设1 <T 预设2 .

[0023] Preferably, when the ambient temperature T 预设1 <T 环 <T 预设2 and when the battery assembly needs to be cooled and heating is required inside the vehicle or indoors, further control the first four-way valve to connect the battery heat exchanger to the exhaust end of the compressor, so that the refrigerant in the heat pump circulation pipeline absorbs heat at the first heat exchanger and releases heat at the second heat exchanger;

[0024] When the ambient temperature T 预设1 <T 环 <T 预设2 and when the battery assembly needs to be heated and heating is required inside the vehicle or indoors, further control the first four-way valve to connect the battery heat exchanger to the suction end of the compressor, so that the refrigerant in the heat pump circulation pipeline releases heat at the first heat exchanger and absorbs heat at the second heat exchanger.

[0025] Preferably, when the second four-way valve includes a first end, a second end, a third end and a fourth end:

[0026] When the ambient temperature T 环 <T 预设1 and when the battery assembly needs to be heated and heating is required inside the vehicle or indoors, control the first end of the second four-way valve to communicate with the second end, and at the same time control the third end of the second four-way valve to communicate with the fourth end;

[0027] When the ambient temperature T 环 >T 预设2 , and when the battery assembly needs to be cooled and the vehicle interior or indoor space needs to be refrigerated, control the first end and the second end of the second four-way valve to communicate, and at the same time control the third end and the fourth end of the second four-way valve to communicate;

[0028] When the ambient temperature T 预设1 <T 环 <T 预设2 , and when the battery assembly needs to be cooled, control the first end and the fourth end of the second four-way valve to communicate, and at the same time control the second end and the third end of the second four-way valve to communicate;

[0029] When the ambient temperature T 预设1 <T 环 <T 预设2 , and when the battery assembly needs to be heated, control the first end and the fourth end of the second four-way valve to communicate, and at the same time control the second end and the third end of the second four-way valve to communicate.

[0030] Preferably, when the ambient temperature T 环 <T 预设1 , and when the battery assembly needs to be heated and the vehicle interior or indoor space needs to be heated, further control the third four-way valve so that the flow direction of the refrigerant in the heat pump circulation pipeline in the first heat exchanger is opposite to the flow direction of the coolant in the motor circulation pipeline;

[0031] When the ambient temperature T 环 >T 预设2 , and when the battery assembly needs to be cooled and the vehicle interior or indoor space needs to be refrigerated, further control the third four-way valve so that the flow direction of the refrigerant in the heat pump circulation pipeline in the first heat exchanger is opposite to the flow direction of the coolant in the motor circulation pipeline;

[0032] When the ambient temperature T 预设1 <T 环 <T 预设2 , and when the battery assembly needs to be cooled, further control the third four-way valve so that the flow direction of the refrigerant in the heat pump circulation pipeline in the first heat exchanger is opposite to the flow direction of the coolant in the motor circulation pipeline;

[0033] When the ambient temperature T 预设1 <T 环 <T 预设2 , and when the battery assembly needs to be heated, further control the third four-way valve so that the flow direction of the refrigerant in the heat pump circulation pipeline in the first heat exchanger is opposite to the flow direction of the coolant in the motor circulation pipeline.

[0034] Preferably, when the third four-way valve includes a fifth end, a sixth end, a seventh end, and an eighth end:

[0035] When the ambient temperature T 环 < T 预设1 , and when the battery assembly needs to be heated and heating is required inside the vehicle or indoors, control the fifth end of the third four-way valve to communicate with the eighth end, and at the same time control the sixth end of the third four-way valve to communicate with the seventh end;

[0036] When the ambient temperature T 环 > T 预设2 , and when the battery assembly needs to be cooled and cooling is required inside the vehicle or indoors, control the fifth end of the third four-way valve to communicate with the sixth end, and at the same time control the seventh end of the third four-way valve to communicate with the eighth end;

[0037] When the ambient temperature T 预设1 < T 环 < T 预设2 , and when the battery assembly needs to be cooled and heating is required inside the vehicle or indoors, control the fifth end of the third four-way valve to communicate with the eighth end, and at the same time control the sixth end of the third four-way valve to communicate with the seventh end;

[0038] When the ambient temperature T 预设1 < T 环 < T 预设2 , and when the battery assembly needs to be heated and cooling is required inside the vehicle or indoors, control the fifth end of the third four-way valve to communicate with the sixth end, and at the same time control the seventh end of the third four-way valve to communicate with the eighth end.

[0039] Preferably, when an external vehicle heat exchanger and a three-way valve are further included:

[0040] When the ambient temperature T 环 < T 预设1 , and when the battery assembly needs to be heated and heating is required inside the vehicle or indoors, further control the three-way valve to be opened so that the external vehicle heat exchanger communicates with the first heat exchanger, and the coolant absorbs heat from outside the vehicle in the external vehicle heat exchanger;

[0041] When the ambient temperature T 环 > T 预设2 , and when the battery assembly needs to be cooled and cooling is required inside the vehicle or indoors, control the three-way valve so that the external vehicle heat exchanger communicates with the first heat exchanger, and the coolant releases heat to outside the vehicle in the external vehicle heat exchanger;

[0042] When the ambient temperature T 预设1 < T 环<T 预设2 and when the battery assembly needs to be cooled, control the three-way valve to connect the outside vehicle heat exchanger with the first heat exchanger, and the coolant releases heat to the outside of the vehicle in the outside vehicle heat exchanger;

[0043] When the ambient temperature is T 预设1 <T 环 <T 预设2 and when the battery assembly needs to be heated, control the three-way valve to connect the outside vehicle heat exchanger with the first heat exchanger, and the coolant absorbs heat from the outside of the vehicle in the outside vehicle heat exchanger.

[0044] The present invention also provides an electric vehicle, which includes the heat management system described in any one of the preceding items.

[0045] A heat management system, a control method and an electric vehicle provided by the present invention have the following beneficial effects:

[0046] The present invention effectively combines the heat pump circulation pipeline, the battery circulation pipeline, and the motor circulation pipeline. That is, the heat pump circulation pipeline and the battery circulation pipeline are effectively combined through a battery heat exchanger, and the heat pump circulation pipeline and the motor circulation pipeline are effectively combined through a first heat exchanger. The air conditioning system, the battery thermal management system, and the drive motor cooling system are integrated, so that the operating temperatures of the battery system and the motor system are maintained within a reasonable range, realizing the heat management of the whole vehicle, and very effectively improving the energy utilization rate of the electric vehicle. Moreover, the air conditioning system, the battery thermal management system, and the drive motor cooling system are integrated into a set of vehicle thermal management system to realize the temperature control of the passenger compartment, the battery pack, the motor, the motor controller, and the charger, greatly reducing the cost, weight, and occupied volume. The heat pump is used to heat and cool the battery pack, improving the battery temperature control accuracy and speed, effectively solving the problem of insufficient air conditioning cooling capacity in low-temperature conditions. The phase change heat transfer mode is used for the battery thermal management in bad weather, improving the battery cooling or heating efficiency, enhancing the battery charge and discharge efficiency, solving the problem of low battery charge and discharge efficiency in low-temperature and high-temperature conditions, improving the battery energy efficiency, and reducing the temperature difference of the battery pack. The waste heat of the battery and the motor is recycled to improve the air conditioning heating efficiency and heating comfort. The battery thermal management adopts a double-loop design, and the double reliability ensures the safety of the battery. And through the setting of the second four-way valve, the battery circulation pipeline and the motor circulation pipeline can be effectively connected or disconnected, so that especially in working conditions such as bad weather (such as low temperature in winter or high temperature in summer), the phase change heat transfer cycle is started, that is, the heat pump circulation pipeline is turned on to effectively heat or cool the battery components. And in working conditions such as the transition season outside bad weather or when the heat pump system fails or malfunctions, the non-phase change heat transfer cycle is started, so that the battery circulation pipeline and the motor circulation pipeline are connected to effectively utilize the heat of the motor components, and / or the heat or cold of the first heat exchanger, and / or the heat or cold of the external heat exchanger of the vehicle to heat or cool the battery components. Through the setting of the third four-way valve, the flow direction of the coolant in the motor circulation pipeline can be effectively switched according to the flow direction of the refrigerant in the first heat exchanger in the heat pump circulation pipeline, so as to effectively ensure that the flow direction of the refrigerant in the first heat exchanger is always opposite to the flow direction of the coolant, further effectively improving the heat transfer efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is the system circulation diagram of the thermal management system of the electric vehicle of the present invention;

[0048] Figure 2 is the system circulation diagram of the thermal management system of the electric vehicle of the present invention in battery thermal management mode 1a;

[0049] Figure 3 is the system circulation diagram of the thermal management system of the electric vehicle of the present invention in battery thermal management mode 1b;

[0050] Figure 4 It is the system cycle diagram of the thermal management system of the electric vehicle of the present invention in battery thermal management mode 1c;

[0051] Figure 5 It is the system cycle diagram of the thermal management system of the electric vehicle of the present invention in battery thermal management mode 1d;

[0052] Figure 6 It is the system cycle diagram of the thermal management system of the electric vehicle of the present invention in battery thermal management mode 2a;

[0053] Figure 7 It is the system cycle diagram of the thermal management system of the electric vehicle of the present invention in battery thermal management mode 2b.

[0054] The reference numerals are represented as:

[0055] 1. Out-of-vehicle heat exchanger; 2. Expansion tank; 3. First heat exchanger; 4. Compressor; 5. Gas-liquid separator; 6. Second heat exchanger; 7. Battery heat exchanger; 8. Battery assembly; 20. Motor assembly; 9. Charger; 10. Motor controller; 11. Motor; 12a. First pump; 12b. Second pump; 13a. First throttling device; 13b. Second throttling device; 14a. First four-way valve; 14b. Second four-way valve; 14b1. First end; 14b2. Second end; 14b3. Third end; 14b4. Fourth end; 14c. Third four-way valve; 14c1. Fifth end; 14c2. Sixth end; 14c3. Seventh end; 14c4. Eighth end; 15. Three-way valve; 401. First pipe section; 402. Second pipe section; 403. First branch; 100. Heat pump circulation pipeline; 200. Battery circulation pipeline; 300. Motor circulation pipeline. Detailed implementation manners

[0056] As Figure 1-7 shown, the dashed lines in the figure represent blocked branches, the double-dashed lines represent the air-conditioning refrigerant circuit, and the arrows represent the flow directions of the refrigerant or the secondary coolant.

[0057] The present invention provides a thermal management system, which includes:

[0058] A heat pump circulation pipeline 100, a battery circulation pipeline 200 and a motor circulation pipeline 300. A compressor 4, a first heat exchanger 3, a second heat exchanger 6 and a battery heat exchanger 7 are arranged on the heat pump circulation pipeline 100. The second heat exchanger 6 can be used to heat or cool the inside of the vehicle or the room. A part of the battery heat exchanger 7 is also arranged on the battery circulation pipeline 200, so that the heat pump circulation pipeline 100 and the battery circulation pipeline 200 can exchange heat at the battery heat exchanger 7. A part of the first heat exchanger 3 is also arranged on the motor circulation pipeline 300, so that the heat pump circulation pipeline 100 and the motor circulation pipeline 300 can exchange heat at the battery heat exchanger 7. A battery assembly 8 is arranged on the battery circulation pipeline 200, and a motor assembly 20 is arranged on the motor circulation pipeline 300;

[0059] It further includes a second four-way valve 14b. The second four-way valve 14b is arranged between the battery circulation pipeline 200 and the motor circulation pipeline 300, so that the battery circulation pipeline 200 and the motor circulation pipeline 300 can be controlled to be connected or disconnected by switching the second four-way valve 14b;

[0060] It further includes a third four-way valve 14c and a second pump 12b. The third four-way valve 14c and the second pump 12b are both arranged on the motor circulation pipeline 300. By switching the third four-way valve 14c, the motor circulation pipeline 300 can be switched between a positive circulation and a reverse circulation. The positive circulation is that the coolant flows in the first direction in the motor circulation pipeline 300, and the reverse circulation is that the coolant flows in the second direction in the motor circulation pipeline 300. The first direction is opposite to the second direction.

[0061] The present invention develops an efficient vehicle thermal management system, which integrates the air conditioning system, the battery thermal management system and the drive motor cooling system into the vehicle thermal management system, improves the energy utilization rate and increases the cruising range.

[0062] The present invention effectively combines a heat pump circulation pipeline, a battery circulation pipeline, and a motor circulation pipeline. That is, the heat pump circulation pipeline and the battery circulation pipeline are effectively combined through a battery heat exchanger, and the heat pump circulation pipeline and the motor circulation pipeline are effectively combined through a first heat exchanger, integrating an air conditioning system, a battery thermal management system, and a drive motor cooling system to keep the operating temperatures of the battery system and the motor system within a reasonable range, realizing the heat management of the whole vehicle, and very effectively improving the energy utilization rate of the electric vehicle. Moreover, the air conditioning system, the battery thermal management system, and the drive motor cooling system are integrated into a set of vehicle thermal management system to realize temperature control of the passenger compartment, the battery pack, the motor, the motor controller, and the charger, greatly reducing the cost, weight, and occupied volume. The heat pump is used to heat and cool the battery pack, improving the battery temperature control accuracy and speed, enhancing the battery energy efficiency, and reducing the temperature difference of the battery pack. The waste heat of the battery and the motor is recycled to improve the heating efficiency and heating comfort of the air conditioning. The battery thermal management adopts a double-loop design, and the double reliability ensures the safety of the battery. And through the setting of the second four-way valve, the battery circulation pipeline and the motor circulation pipeline can be effectively connected or disconnected, so that especially in harsh weather conditions (such as low temperature in winter or high temperature in summer, etc.), the phase change heat exchange cycle is started, that is, the heat pump circulation pipeline is opened to effectively heat or cool the battery components. And in working conditions other than harsh weather, such as in transitional seasons, etc., or when the heat pump system fails or malfunctions, the non-phase change heat exchange cycle is started, making the battery circulation pipeline and the motor circulation pipeline connected to effectively utilize the heat of the motor components, and / or the heat or cold of the first heat exchanger, and / or the heat or cold of the external heat exchanger of the vehicle to heat or cool the battery components. Through the setting of the third four-way valve, the flow direction of the coolant in the motor circulation pipeline can be effectively switched according to the flow direction of the refrigerant in the first heat exchanger in the heat pump circulation pipeline to effectively ensure that the flow direction of the refrigerant in the first heat exchanger is always opposite to the flow direction of the coolant, further effectively improving the heat exchange efficiency.

[0063] The present invention designs a comprehensive thermal management system for temperature control of the passenger compartment, the battery, the motor and its electronic control, and the charger, achieving the goals of waste heat utilization, precise temperature control, and improving the efficiency of the vehicle thermal management system. As Figure 1 The circulation diagram of the thermal management system is mainly divided into two parts, the air conditioning refrigerant circuit and the coolant circuit. Among them, the coolant circuit is divided into two modes, namely the first battery thermal management mode and the second battery thermal management mode. The first battery thermal management mode is phase change heat exchange, and the coolant in the battery branch exchanges heat with the air conditioning refrigerant to cool and heat the battery, that is, the battery branch and the motor system branch are not connected; the second battery thermal management mode is non-phase change heat exchange, and the coolant in the battery branch and the coolant in the motor system branch are connected in series, and the coolant exchanges heat in the air conditioning condenser or the external heat exchanger of the vehicle to adjust the temperature of the coolant, and further adjust the temperatures of the battery and the motor system.

[0064] 1. The air-conditioning refrigerant circuit arranges only one evaporator inside the carriage, with the heat exchange medium being refrigerant - carriage air, and one condenser outside the carriage, with the heat exchange medium being refrigerant - secondary refrigerant. A four-way valve is set to switch the refrigeration and heating modes.

[0065] 2. The secondary refrigerant circuit sets a double four-way valve and a three-way valve to switch the operation mode of the secondary refrigerant, namely the first battery thermal management mode - phase change heat exchange and the second battery thermal management mode - non-phase change heat exchange. Phase change heat exchange mode: The secondary refrigerant in the battery branch exchanges heat with the air-conditioning refrigerant to cool and heat the battery, that is, the battery branch and the motor system branch are not connected; Non-phase change heat exchange mode: The secondary refrigerant in the battery branch and the secondary refrigerant in the motor system branch are connected in series, and the secondary refrigerant exchanges heat in the air-conditioning condenser or the external heat exchanger of the vehicle to adjust the temperature of the secondary refrigerant, and further adjust the temperature of the battery and the motor system. The phase change heat exchange mode is used for battery thermal management in bad weather to improve the battery cooling efficiency or heating efficiency and enhance the battery charge and discharge efficiency; At the same time, if the phase change cooling system fails in bad weather, the non-phase change heat exchange cycle is started to maintain the battery temperature within a reasonable range and improve the safety and reliability of the battery; In addition, the non-phase change heat exchange mode is used for battery thermal management in the transitional season.

[0066] 3. The air-conditioning refrigerant circuit and the secondary refrigerant circuit cooperate with each other, not only realizing the dual management of battery thermal management, but also making full use of the heat dissipation of the heat source motor system to heat the battery and the carriage when heating the carriage in winter, reducing the power consumption of the air-conditioning system; When the battery generates a large amount of heat, the heat dissipation of the battery can also be fully utilized to heat the carriage.

[0067] 4. In the first battery thermal management mode, when the battery needs to be heated, the flow directions of the two media on both sides in the battery heat exchanger are countercurrent, increasing the heat exchange efficiency.

[0068] 5. When the refrigerant circuit operates in the refrigeration and heating modes, the flow directions of the heat exchange media on both sides of the air-conditioning condenser are countercurrent, increasing the heat exchange efficiency.

[0069] The air-conditioning refrigerant circuit (such as Figure 1):Adopt a first four-way valve 14a, a second heat exchanger 6 inside the carriage, with the heat exchange medium being refrigerant and the air inside the carriage, and an external heat exchanger of the carriage (the first heat exchanger 3), with the heat exchange medium being refrigerant and the secondary refrigerant. Starting from the suction port of the compressor, in the refrigeration mode, the refrigerant flow direction is: compressor 4 → first four-way valve 14a → first heat exchanger 3 → first throttling device 13a and second throttling device 13b (preferably an electronic expansion valve) → second heat exchanger 6 and battery heat exchanger 7 → first four-way valve 14a → gas-liquid separator 5 → compressor 4. In the heating mode, the refrigerant flow direction is: compressor 4 → first four-way valve 14a → second heat exchanger 6 and battery heat exchanger 7 → first throttling device 13a and second throttling device 13b → first heat exchanger 3 → first four-way valve 14a → gas-liquid separator 5 → compressor 4. (Here, in the refrigeration mode and the heating mode, by controlling the opening degrees of the first throttling device 13a and the second throttling device 13b, the second heat exchanger 6 and the battery heat exchanger 7 can operate at different times.)

[0070] The secondary refrigerant circuit of the first battery thermal management mode (such as Figure 2 and Figure 3 , Figure 4 , Figure 5 ) is further divided into 2 circuits, namely the internal circulation and the external circulation. The internal circulation conducts thermal management for the battery module 8. Starting from the inlet of the first pump 12a, the secondary refrigerant flow direction is: first pump 12a → second four-way valve 14b → battery heat exchanger 7 → battery module 8 → first pump 12a. The external circulation conducts thermal management for the motor module 20 (including the charger 9, the motor controller 10, and the motor 11). According to different flow directions, the third four-way valve 14c changes its direction and is further divided into 2 circuits, namely the positive circulation and the reverse circulation. Reverse circulation (such as Figure 2 and Figure 3 ):Starting from the inlet of the second pump 12b, the secondary refrigerant flow direction is: second pump 12b → third four-way valve 14c → charger 9 → motor controller 10 → motor 11 → first heat exchanger 3 → expansion tank 2 → three-way valve 15 → external heat exchanger 1 (or bypass) → second four-way valve 14b → third four-way valve 14c → second pump 12b. Positive circulation (such as Figure 4 and Figure 5 ):Starting from the inlet of the second pump 12b, the secondary refrigerant flow direction is: second pump 12b → third four-way valve 14c → second four-way valve 14b → external heat exchanger 1 (or bypass) → three-way valve 15 → expansion tank 2 → first heat exchanger 3 → motor 11 → motor controller 10 → charger 9 → third four-way valve 14c → second pump 12b.

[0071] Preferably, when the battery circulation pipeline 200 and the motor circulation pipeline 300 are in communication, the battery circulation pipeline 200 and the motor circulation pipeline 300 together form a loop. When the battery circulation pipeline 200 and the motor circulation pipeline 300 are not in communication, the battery circulation pipeline 200 and the motor circulation pipeline 300 respectively form closed loops. This is a preferred form of the two battery thermal management modes of the battery circulation pipeline of the present invention. That is, the first battery thermal management mode is that the battery circulation pipeline 200 and the motor circulation pipeline 300 are not in communication, and the battery circulation pipeline 200 and the motor circulation pipeline 300 respectively form closed loops. This connection method is applicable to working conditions under high loads (such as low temperature in winter or high temperature in summer). Heat exchange is carried out between the battery circulation pipeline and the heat pump circulation pipeline, and the battery assembly is heated or cooled by the heat pump system; the second battery thermal management mode is that the battery circulation pipeline 200 and the motor circulation pipeline 300 are in communication, and the battery circulation pipeline 200 and the motor circulation pipeline 300 together form a loop. This connection method is applicable to working conditions under low loads (such as transitional seasons, such as spring and autumn, or when the heat pump system fails and cannot work properly). By connecting the battery circulation pipeline in series with the motor circulation pipeline, at least one of the motor assembly, the first heat exchanger, and the vehicle exterior heat exchanger is used to heat or cool the battery assembly through the series connection of the coolant.

[0072] Preferably, the second four-way valve 14b includes a first end 14b1, a second end 14b2, a third end 14b3, and a fourth end 14b4. The first end and the second end are respectively connected to the battery circulation pipeline 200, so that when the first end and the second end are connected and the third end and the fourth end are connected, the battery circulation pipeline 200 forms a loop. When the first end and the fourth end are connected and the second end and the third end are connected, the battery circulation pipeline 200 and the motor circulation pipeline 300 together form a loop. This is a further preferred structural form of the second four-way valve of the present invention. That is, the connection of the first end and the second end can enable the battery circulation pipeline to form a closed loop, realizing the first battery thermal management mode. The connection of the first end and the fourth end and the connection of the second end and the third end can effectively connect the battery circulation pipeline and the motor circulation pipeline in series to form a large loop, and the motor assembly can be effectively cooled through the large loop, and the battery assembly can be cooled or heated.

[0073] Preferably, the third four-way valve 14c includes a fifth end 14c1, a sixth end 14c2, a seventh end 14c3, and an eighth end 14c4. The fifth end 14c1 is communicated with the outlet end of the second pump 12b. The sixth end 14c2 is communicated with the fourth end 14b4 of the second four-way valve 14b. The seventh end 14c3 is communicated with the inlet end of the second pump 12b. The eighth end 14c4 is communicated with one end of the motor assembly 20. This is a further preferred structural form of the third four-way valve of the present invention. That is, the communication between the fifth end and the sixth end, and the communication between the seventh end and the eighth end can enable the motor circulation pipeline to flow in the positive circulation according to Figure 4-5 in the figure (clockwise in the figure). This control method is applicable to the mode in which the first heat exchanger 3 in the heat pump circulation pipeline releases heat to the outside (that is, the in-vehicle heat exchanger or the second heat exchanger 6 is in the refrigeration mode). Thus, the refrigerant in the heat pump circulation pipeline and the coolant in the motor circulation pipeline form a reverse flow in the first heat exchanger (that is, countercurrent), effectively improving the heat exchange efficiency. The communication between the fifth end and the eighth end, and the communication between the sixth end and the seventh end can enable the motor circulation pipeline to flow in the reverse circulation according to Figure 2-3 in FIGS. 6-7 (counterclockwise in the figure). This control method is applicable to the mode in which the first heat exchanger 3 in the heat pump circulation pipeline absorbs heat from the outside (that is, the in-vehicle heat exchanger or the second heat exchanger 6 is in the heating mode). Thus, the refrigerant in the heat pump circulation pipeline and the coolant in the motor circulation pipeline form a reverse flow in the first heat exchanger (that is, countercurrent), effectively improving the heat exchange efficiency.

[0074] Preferably, the battery heat exchanger 7 is arranged in parallel with the second heat exchanger 6; and / or, a first pump 12a is arranged on the battery circulation pipeline 200; and / or, the motor assembly 20 includes a charger 9, a motor controller 10, and a motor 11 which are arranged in series; and / or, a first four-way valve 14a is further arranged at the exhaust end of the compressor 4 on the heat pump circulation pipeline 100; and / or, a gas-liquid separator 5 is further arranged at the suction end of the compressor 4 on the heat pump circulation pipeline 100.

[0075] By arranging the battery heat exchanger and the second heat exchanger in parallel, it is possible to heat or cool the battery heat exchanger simultaneously while the second heat exchanger (the in-vehicle or indoor heat exchanger) heats or cools the interior of the vehicle or the room, forming the first battery thermal management mode; the first pump can effectively drive the cooling fluid to flow in the battery circulation pipeline, receive heat or cold in the battery heat exchanger, and then heat or cool the battery assembly. The charger, the motor controller, and the motor all generate heat. Therefore, the coolant in the motor circulation pipeline can effectively absorb the heat of the three and cool them down, and reasonably and effectively utilize their heat; the first four-way valve can effectively adjust and control the refrigerant flow direction in the heat pump circulation pipeline, thereby effectively switching between cooling and heating the interior of the vehicle or the room by the second heat exchanger; the gas-liquid separator is used to separate the liquid in the intake air.

[0076] Preferably, on the heat pump circulation pipeline 100, the pipe section where the second heat exchanger 6 is located is the first pipe section 401, and the pipe section where the battery heat exchanger 7 is located on the heat pump circulation pipeline 100 is the second pipe section 402. The first pipe section 401 and the second pipe section 402 are connected in parallel, and a first throttling device 13a is provided on the first pipe section 401, and a second throttling device 13b is provided on the second pipe section 402. This is the preferred structural form between the second heat exchanger and the battery heat exchanger on the heat pump circulation pipeline of the present invention. Two pipe sections effectively form parallel branches, and the first throttling device is used to adjust the refrigerant flow rate in the second heat exchanger 6 or control the opening and closing, and the second throttling device is used to adjust the refrigerant flow rate in the battery heat exchanger 7 or control the opening and closing.

[0077] Preferably, the first pump 12a is a water pump; and / or, the second pump 12b is a water pump; and / or, an expansion tank 2 is further provided on the motor circulation pipeline 300. The first pump and the second pump are water pumps respectively or simultaneously, which can effectively form a double-loop design, use water to exchange heat with the battery assembly or the motor assembly, prevent refrigerant leakage, and have double reliability, ensuring the safety of the battery and motor assemblies.

[0078] Preferably, a first branch 403 is also provided in parallel at the pipe section on the motor circulation pipeline 300 and between the second four-way valve 14b and the first heat exchanger 3. An out-of-vehicle heat exchanger 1 is provided on the first branch 403, and a three-way valve 15 is also provided at the position where the first branch 403 is connected to the motor circulation pipeline 300. By providing the first branch and the out-of-vehicle heat exchanger on the motor circulation pipeline, the three-way valve can be opened as needed to connect the out-of-vehicle heat exchanger, so as to effectively draw in heat or cold from outside the vehicle to cool or heat the battery assembly and / or the motor assembly, effectively and reasonably utilize energy, and further improve the energy utilization rate.

[0079] The present invention also provides a control method for a thermal management system as described in any one of the preceding items, wherein:

[0080] When the first four-way valve 14a, the second four-way valve 14b, the first throttling device 13a, and the second throttling device 13b are included:

[0081] When the ambient temperature T 环 < T 预设1 (preferably in winter), and when the battery assembly 8 needs to be heated and heating is required inside the vehicle or indoors, control the first four-way valve 14a so that the battery heat exchanger 7 communicates with the exhaust end of the compressor 4, and at the same time control the second four-way valve 14b so that the battery circulation pipeline 200 and the motor circulation pipeline 300 are not connected. The battery circulation pipeline 200 and the motor circulation pipeline 300 respectively form closed loops, and control both the first throttling device 13a and the second throttling device 13b to be opened; where T 预设1 can be a value or a numerical range;

[0082] When the ambient temperature T 环 > T 预设2 (preferably in summer), and when the battery assembly 8 needs to be cooled and cooling is required inside the vehicle or indoors, control the first four-way valve 14a so that the battery heat exchanger 7 communicates with the suction end of the compressor 4, and at the same time control the second four-way valve 14b so that the battery circulation pipeline 200 and the motor circulation pipeline 300 are not connected. The battery circulation pipeline 200 and the motor circulation pipeline 300 respectively form closed loops, and control both the first throttling device 13a and the second throttling device 13b to be opened; where T 预设2 can be a value or a numerical range;

[0083] When the ambient temperature T 预设1 < T 环 < T 预设2 (preferably in transitional seasons such as spring and autumn), and when the battery assembly 8 needs to be cooled, control the second four-way valve 14b so that the battery circulation pipeline 200 and the motor circulation pipeline 300 are connected, so that the battery circulation pipeline 200 and the motor circulation pipeline 300 jointly form a loop, and when the external heat exchanger 1 is included, the coolant in the motor circulation pipeline releases heat in the first heat exchanger 3 and / or in the external heat exchanger 1, and control the first throttling device 13a to be opened and control the second throttling device 13b to be closed;

[0084] When the ambient temperature T 预设1 < T 环 < T 预设2(Preferably in the transitional seasons, such as spring and autumn), and when the battery module 8 needs to be heated, control the second four-way valve 14b to connect the battery circulation pipeline 200 and the motor circulation pipeline 300, so that the battery circulation pipeline 200 and the motor circulation pipeline 300 jointly form a loop. And when the outside heat exchanger 1 is included, the coolant in the motor circulation pipeline absorbs heat in the first heat exchanger 3, and / or absorbs heat in the outside heat exchanger 1, and / or absorbs heat in the motor module 20, and control the first throttling device 13a to open and control the second throttling device 13b to close.

[0085] These are the control forms of two different battery thermal management modes of the present invention under four working conditions when the battery module needs to be heated or cooled, effectively achieving the effect of cooling the battery module through the heat pump circulation pipeline in the first battery thermal management mode, achieving the effect of heating the battery module through the heat pump circulation pipeline in the first battery thermal management mode, achieving the effect of cooling the battery module through the motor circulation pipeline in the second battery thermal management mode, achieving the effect of heating the battery module through the motor circulation pipeline in the second battery thermal management mode, and being able to perform targeted control for working conditions such as low temperature in winter, high temperature in summer, transitional seasons or heat pump system failures, etc., to achieve effective cooling or heating of the battery module, as well as effective cooling of the motor module, ensuring the normal, safe and efficient operation of the electric vehicle, and maximizing the energy utilization rate.

[0086] Preferably, when the ambient temperature T 预设1 < T 环 < T 预设2 , and when the battery module 8 needs to be cooled and heating is required inside the vehicle or indoors, also control the first four-way valve 14a to connect the battery heat exchanger 7 to the exhaust end of the compressor 4, so that the refrigerant in the heat pump circulation pipeline 100 absorbs heat at the first heat exchanger 3 and releases heat at the second heat exchanger 6;

[0087] When the ambient temperature T 预设1 < T 环 < T 预设2 , and when the battery module 8 needs to be heated and heating is required inside the vehicle or indoors, also control the first four-way valve 14a to connect the battery heat exchanger 7 to the suction end of the compressor 4, so that the refrigerant in the heat pump circulation pipeline 100 releases heat at the first heat exchanger 3 and absorbs heat at the second heat exchanger 6.

[0088] This is a further preferred control mode for the electric vehicle of the present invention operating in an external environment during the transitional season (the temperature is not very high or very low, such as in spring and autumn). By controlling the first four-way valve, the flow direction of the refrigerant in the heat pump circulation pipeline can be controlled. At this time, the cooling or heating of the battery assembly is achieved through the secondary coolant pipeline. However, by adjusting the flow direction of the refrigerant in the heat pump circulation pipeline, it is possible to control whether the refrigerant in the first heat exchanger absorbs or releases heat, so as to improve the heat absorption and release efficiency of the battery assembly using the heat pump according to the heat absorption and release requirements of the battery assembly. For example, when the battery assembly needs to be cooled, controlling the first four-way valve causes the refrigerant to absorb heat at the first heat exchanger, which can effectively reduce the temperature of the secondary coolant, and thus effectively improve the heat dissipation cooling efficiency of the battery assembly; when the battery assembly needs to be heated, controlling the first four-way valve causes the refrigerant to release heat at the first heat exchanger, which can effectively increase the temperature of the secondary coolant, and thus effectively improve the heating efficiency of the battery assembly.

[0089] Preferably, when the second four-way valve 14b includes a first end 14b1, a second end 14b2, a third end 14b3, and a fourth end 14b4:

[0090] When the ambient temperature T 环 <T 预设1 (winter), and when the battery assembly 8 needs to be heated and heating is required inside the vehicle or indoors, control the second four-way valve 14b to connect the first end 14b1 and the second end 14b2, and at the same time control the third end 14b3 and the fourth end 14b4 of the second four-way valve 14b to be connected;

[0091] When the ambient temperature T 环 >T 预设2 (summer), and when the battery assembly 8 needs to be cooled and cooling is required inside the vehicle or indoors, control the second four-way valve 14b to connect the first end 14b1 and the second end 14b2, and at the same time control the third end 14b3 and the fourth end 14b4 of the second four-way valve 14b to be connected;

[0092] When the ambient temperature T 预设1 <T 环 <T 预设2 (transitional season, such as spring and autumn), and when the battery assembly 8 needs to be cooled, control the second four-way valve 14b to connect the first end 14b1 and the fourth end 14b4, and at the same time control the second end 14b2 and the third end 14b3 of the second four-way valve 14b to be connected;

[0093] When the ambient temperature T 预设1 <T 环 <T 预设2(During the transitional seasons, such as spring and autumn), and when the battery module 8 needs to be heated, control the first end 14b1 of the second four-way valve 14b to communicate with the fourth end 14b4, and at the same time control the second end 14b2 of the second four-way valve 14b to communicate with the third end 14b3.

[0094] These are further preferred control forms of the two different battery thermal management modes of the present invention under four working conditions where the battery module needs to be heated or cooled, that is, mainly through the effective switching connection of the four ends of the second four-way valve, effectively achieving the effect of cooling the battery module through the heat pump circulation pipeline in the first battery thermal management mode, achieving the effect of heating the battery module through the heat pump circulation pipeline in the first battery thermal management mode, achieving the effect of cooling the battery module through the motor circulation pipeline in the second battery thermal management mode, achieving the effect of heating the battery module through the motor circulation pipeline in the second battery thermal management mode, being able to perform targeted control for working conditions such as low temperature in winter, high temperature in summer, transitional seasons or heat pump system failures, etc., realizing the effective cooling or heating of the battery module, as well as the effective cooling of the motor module, ensuring the normal, safe and efficient operation of the electric vehicle, and achieving the highest energy utilization rate.

[0095] Preferably, when the ambient temperature T 环 < T 预设1 , and when the battery module 8 needs to be heated and heating is required inside the vehicle or indoors, also control the third four-way valve 14c so that the flow direction of the refrigerant in the heat pump circulation pipeline 100 in the first heat exchanger 3 is opposite to the flow direction of the coolant in the motor circulation pipeline 300;

[0096] When the ambient temperature T 环 > T 预设2 , and when the battery module 8 needs to be cooled and cooling is required inside the vehicle or indoors, also control the third four-way valve 14c so that the flow direction of the refrigerant in the heat pump circulation pipeline 100 in the first heat exchanger 3 is opposite to the flow direction of the coolant in the motor circulation pipeline 300;

[0097] When the ambient temperature T 预设1 < T 环 < T 预设2 (During the transitional seasons, such as spring and autumn), and when the battery module 8 needs to be cooled, also control the third four-way valve 14c so that the flow direction of the refrigerant in the heat pump circulation pipeline 100 in the first heat exchanger 3 is opposite to the flow direction of the coolant in the motor circulation pipeline 300;

[0098] When the ambient temperature T 预设1 < T 环 < T 预设2(During the transitional seasons, such as spring and autumn), and when the battery module 8 needs to be heated, the third four-way valve 14c is also controlled so that the flow direction of the refrigerant in the heat pump cycle pipeline 100 in the first heat exchanger 3 is opposite to the flow direction of the coolant in the motor cycle pipeline 300.

[0099] These are the further preferred control forms of the two different battery thermal management modes of the present invention under four working conditions where the battery module needs to be heated or cooled. It effectively realizes the effect of forming countercurrent heat exchange between the heat pump cycle pipeline and the motor cycle pipeline at the first heat exchanger while cooling the battery module in the first battery thermal management mode, improving the heat exchange efficiency. It effectively realizes the effect of forming countercurrent heat exchange between the heat pump cycle pipeline and the motor cycle pipeline at the first heat exchanger while heating the battery module in the first battery thermal management mode, improving the heat exchange efficiency. It effectively realizes the effect of forming countercurrent heat exchange between the heat pump cycle pipeline and the motor cycle pipeline at the first heat exchanger while cooling the battery module in the second battery thermal management mode, improving the heat exchange efficiency. It effectively realizes the effect of forming countercurrent heat exchange between the heat pump cycle pipeline and the motor cycle pipeline at the first heat exchanger while heating the battery module in the second battery thermal management mode, improving the heat exchange efficiency. It can perform targeted control for working conditions such as low temperature in winter, high temperature in summer, transitional seasons or heat pump system failures, etc., to achieve effective cooling or heating of the battery module, as well as effective cooling of the motor module, ensuring the normal, safe and efficient operation of the electric vehicle, and achieving the highest energy utilization rate.

[0100] Preferably, when the third four-way valve 14c includes a fifth end 14c1, a sixth end 14c2, a seventh end 14c3 and an eighth end 14c4:

[0101] When the ambient temperature T 环 < T 预设1 , and when the battery module 8 needs to be heated and heating is required inside the vehicle or indoors, the fifth end 14c1 of the third four-way valve 14c is controlled to communicate with the eighth end 14c4, and at the same time, the sixth end 14c2 of the third four-way valve 14c is controlled to communicate with the seventh end 14c3;

[0102] When the ambient temperature T 环 > T 预设2 , and when the battery module 8 needs to be cooled and cooling is required inside the vehicle or indoors, the fifth end 14c1 of the third four-way valve 14c is controlled to communicate with the sixth end 14c2, and at the same time, the seventh end 14c3 of the third four-way valve 14c is controlled to communicate with the eighth end 14c4;

[0103] When the ambient temperature T 预设1 < T 环 < T 预设2(During the transitional seasons, such as spring and autumn), and when the battery module 8 needs to be cooled and heating is required inside the vehicle or indoors, control the fifth end 14c1 of the third four-way valve 14c to communicate with the eighth end 14c4, and at the same time control the sixth end 14c2 of the third four-way valve 14c to communicate with the seventh end 14c3;

[0104] When the ambient temperature T 预设1 < T 环 < T 预设2 (During the transitional seasons, such as spring and autumn), and when the battery module 8 needs to be heated and cooling is required inside the vehicle or indoors, control the fifth end 14c1 of the third four-way valve 14c to communicate with the sixth end 14c2, and at the same time control the seventh end 14c3 of the third four-way valve 14c to communicate with the eighth end 14c4.

[0105] These are further preferred control forms of two different battery thermal management modes of the present invention under four working conditions where the battery module needs to be heated or cooled, that is, effectively switching and connecting through the four ends of the third four-way valve, effectively achieving the effect of forming countercurrent heat exchange between the heat pump circulation pipeline and the motor circulation pipeline at the first heat exchanger while cooling the battery module in the first battery thermal management mode, improving the heat exchange efficiency, effectively achieving the effect of forming countercurrent heat exchange between the heat pump circulation pipeline and the motor circulation pipeline at the first heat exchanger while heating the battery module in the first battery thermal management mode, improving the heat exchange efficiency, effectively achieving the effect of forming countercurrent heat exchange between the heat pump circulation pipeline and the motor circulation pipeline at the first heat exchanger while cooling the battery module in the second battery thermal management mode, improving the heat exchange efficiency, and effectively achieving the effect of forming countercurrent heat exchange between the heat pump circulation pipeline and the motor circulation pipeline at the first heat exchanger while heating the battery module in the second battery thermal management mode, improving the heat exchange efficiency.

[0106] Preferably, when an external heat exchanger 1 and a three-way valve 15 are further included:

[0107] When the ambient temperature T 环 < T 预设1 , and when the battery module 8 needs to be heated and heating is required inside the vehicle or indoors, also control to open the three-way valve 15 so that the external heat exchanger 1 communicates with the first heat exchanger 3, and the coolant absorbs heat from the outside of the vehicle in the external heat exchanger 1;

[0108] When the ambient temperature T 环 > T 预设2 , and when the battery module 8 needs to be cooled and cooling is required inside the vehicle or indoors, control the three-way valve 15 so that the external heat exchanger 1 communicates with the first heat exchanger 3, and the coolant releases heat to the outside of the vehicle in the external heat exchanger 1;

[0109] When the ambient temperature T 预设1 <T 环 <T 预设2 (During the transitional seasons, such as spring and autumn), and when the battery module 8 needs to be cooled, control the three-way valve 15 to connect the outside vehicle heat exchanger 1 with the first heat exchanger 3, and the coolant releases heat to the outside of the vehicle in the outside vehicle heat exchanger 1;

[0110] When the ambient temperature T 预设1 <T 环 <T 预设2 (During the transitional seasons, such as spring and autumn), and when the battery module 8 needs to be heated, control the three-way valve 15 to connect the outside vehicle heat exchanger 1 with the first heat exchanger 3, and the coolant absorbs heat from the outside of the vehicle in the outside vehicle heat exchanger 1.

[0111] These are further preferred control forms of two different battery thermal management modes of the present invention under four working conditions where the battery module needs to be heated or cooled, that is, mainly through the effective switching connection of the three-way valve, effectively realizing the effective low inhalation or release of heat by using the outside vehicle heat exchanger while cooling the battery module in the first battery thermal management mode, effectively and reasonably utilizing energy, and further improving the energy utilization rate; effectively realizing the effective low inhalation or release of heat by using the outside vehicle heat exchanger while heating the battery module in the first battery thermal management mode, effectively and reasonably utilizing energy, and further improving the energy utilization rate; effectively realizing the effective low inhalation or release of heat by using the outside vehicle heat exchanger while cooling the battery module in the second battery thermal management mode, effectively and reasonably utilizing energy, and further improving the energy utilization rate; effectively realizing the effective low inhalation or release of heat by using the outside vehicle heat exchanger while heating the battery module in the second battery thermal management mode, effectively and reasonably utilizing energy, and further improving the energy utilization rate.

[0112] The present invention also provides an electric vehicle, which includes the thermal management system described in any one of the preceding items.

[0113] Battery thermal management mode 1a (such as Figure 2 ) - Phase change heat transfer:

[0114] The thermal management of the battery 8 is achieved by the heat exchange between the coolant and the air-conditioning refrigerant, so as to keep the battery temperature within a reasonable range. When the temperature of the internal circulation battery is lower than the lower limit of the normal operating temperature, the air conditioner operates in the heating mode. The flow directions of the two-side media in the battery heat exchanger 7 are countercurrent (the design purpose is to achieve countercurrent to enhance heat exchange). By controlling the opening degree of the second throttling device 13b and the frequency of the first pump 12a, 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, the external circulation coolant transfers the heat dissipated by the motor system and the heat from the external heat source to the air-conditioning to cool the first heat exchanger 3, achieving waste heat utilization.

[0115] Battery thermal management mode 1b (such as Figure 3 ) - Phase change heat transfer:

[0116] The difference between battery thermal management mode 1b and battery thermal management mode 1a lies in the reversal of the three-way valve, that is, the external circulation coolant bypasses the external heat exchanger 1 after coming out of the three-way valve 15 and enters the motor system branch through the second four-way valve 14b. This cycle is applicable to the situation where the heating requirements of the carriage and the battery heating amount are small, that is, the waste heat recovery of the motor system meets the heating requirements of the carriage and the battery heating amount, and there is no need to take heat from the environment. This mode is the outdoor low-temperature carriage heating mode.

[0117] Battery thermal management mode 1c (such as Figure 4 ) - Phase change heat transfer:

[0118] When the temperature of the internal circulation battery exceeds the upper limit of the normal operating temperature, the air conditioner operates in the cooling mode. The flow directions of the two-side media in the battery heat exchanger 7 are co-current. By controlling the opening degree of the second throttling device 13b and the frequency of the first pump 12a, 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. At this time, the external circulation coolant releases heat through the external heat exchanger 1 and then cools the first heat exchanger 3, and then flows through the motor system to cool the motor system.

[0119] Battery thermal management mode 1d (such as Figure 5 ) - Phase change heat transfer:

[0120] The difference between battery thermal management mode 1d and battery thermal management mode 1c lies in the reversal of the three-way valve, that is, the external circulation coolant does not pass through the external heat exchanger 1, but enters the first heat exchanger 3 from the bypass pipe to the three-way valve 15. This cycle is applicable to the situation where the heating requirements of the carriage and the battery heating amount are small in winter, that is, the waste heat recovery of the motor system meets the heating requirements of the carriage and the battery heating amount, and there is no need to take heat from the environment. At this time, the flow direction of the external circulation coolant and the refrigerant in the first heat exchanger 3 is co-current, and the heat exchange effect is slightly worse compared with the countercurrent.

[0121] The secondary battery thermal management mode coolant circuit connects the battery and the motor system in series. That is, the battery heat exchanger 7 does not work, and the second four-way valve 14b changes its direction. Starting from the inlet of the first pump 12a, the coolant flow direction is: the first pump 12a → the second four-way valve 14b → the third four-way valve 14c → the second pump 12b → the third four-way valve 14c → the charger 9 → the motor controller 10 → the motor 11 → the first heat exchanger 3 → the expansion tank 2 → the three-way valve 15 → the external heat exchanger 1 (or bypass) → the second four-way valve 14b → the battery heat exchanger 7 → the battery pack 8 → the first pump 12a.

[0122] Battery thermal management mode 2a (such as Figure 6 ) - non-phase change heat transfer:

[0123] The thermal management of the battery pack 8 and the motor system is in series. The coolant exchanges heat with the refrigerant only at the first heat exchanger 3 to maintain the normal temperature of the battery and the motor system. If the battery temperature exceeds the upper limit of the normal operating temperature, the battery needs to be cooled, and the coolant flow direction is as described above. The secondary battery thermal management mode transfers the heat generated by the battery and the heat from the external environmental heat source to the first heat exchanger 3 to increase the heat generation in the passenger compartment for heat recovery. Additionally, if the motor is operating, the secondary battery thermal management mode transfers the heat generated by the battery, the heat dissipated by the motor system, and the heat from the external environmental heat source to the first heat exchanger 3 to further increase the heat generation in the passenger compartment. This situation applies to the transitional season. It is also possible to transfer the heat generated by the battery to the external heat exchanger, that is, the first heat exchanger 3 does not work. This situation applies to summer charging (when the battery temperature is too high during summer charging and needs to be cooled). Additionally, if the motor is operating, the heat generated by the battery and the heat dissipated by the motor system are transferred to the external heat exchanger, that is, the first heat exchanger 3 does not work. This situation applies to the transitional season.

[0124] If the battery temperature is below the lower limit of the normal operating temperature, the battery needs to be heated, and the coolant flow direction is as described above. The coolant absorbs heat from the motor system and then releases heat at the first heat exchanger 3. Then it absorbs environmental heat at the external heat exchanger 1 and then changes its direction through the four-way valve 14b and enters the battery branch to heat the battery.

[0125] Battery thermal management mode 2b (such as Figure 7 ) - non-phase change heat transfer:

[0126] The difference between battery thermal management mode 2b and battery thermal management mode 2a is the change of direction of the three-way valve. That is, the external circulation coolant does not pass through the external heat exchanger 1 after coming out of the three-way valve 15 but bypasses to the four-way valve 14b and enters the battery branch. If the battery needs to be cooled, battery thermal management mode 2b transfers the heat generated by the battery and the heat dissipated by the motor system to the first heat exchanger 3 to further increase the heat generation in the passenger compartment. This situation applies to the case where the heat demand in the passenger compartment is small, that is, the waste heat recovery of the battery and the motor system meets the heat demand in the passenger compartment, and there is no need to extract heat from the environment anymore.

[0127] If the battery needs to be heated, the secondary coolant absorbs heat from the motor system and then enters the battery branch through a series of components and is reversed by the four-way valve 14b to heat the battery. At this time, the first heat exchanger 3 does not work. This situation is applicable when the heat dissipation of the motor system meets the battery heating requirement and is applied at the initial stage of starting a pure electric vehicle in winter.

[0128] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention. The above is only the preferred implementation manner of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and variations can still be made, and these improvements and variations should also be regarded as within the protection scope of the present invention.

Claims

1. A thermal management system, characterized in that: Including: A heat pump circulation pipeline (100), a battery circulation pipeline (200), and a motor circulation pipeline (300). A compressor (4), a first heat exchanger (3), a second heat exchanger (6), and a battery heat exchanger (7) are provided on the heat pump circulation pipeline (100). Heating or cooling of the vehicle interior or indoor can be performed through the second heat exchanger (6). A part of the battery heat exchanger (7) is also provided on the battery circulation pipeline (200) so that heat exchange can occur between the heat pump circulation pipeline (100) and the battery circulation pipeline (200) at the battery heat exchanger (7). A part of the first heat exchanger (3) is also provided on the motor circulation pipeline (300) so that heat exchange can occur between the heat pump circulation pipeline (100) and the motor circulation pipeline (300) at the battery heat exchanger (7). A battery assembly (8) is provided on the battery circulation pipeline (200), and a motor assembly (20) is provided on the motor circulation pipeline (300); It further includes a second four-way valve (14b). The second four-way valve (14b) is provided between the battery circulation pipeline (200) and the motor circulation pipeline (300) so that the battery circulation pipeline (200) and the motor circulation pipeline (300) can be controlled to be connected or disconnected by switching the second four-way valve (14b); It further includes a third four-way valve (14c) and a second pump (12b). Both the third four-way valve (14c) and the second pump (12b) are provided on the motor circulation pipeline (300) so that the motor circulation pipeline (300) can be switched between a positive circulation and a reverse circulation by switching the third four-way valve (14c). The positive circulation is that the refrigerant flows in a first direction in the motor circulation pipeline (300), and the reverse circulation is that the refrigerant flows in a second direction in the motor circulation pipeline (300). The first direction is opposite to the second direction; A first four-way valve (14a) is further provided at the exhaust end of the compressor (4) on the heat pump circulation pipeline (100); on the heat pump circulation pipeline (100), the pipe section where the second heat exchanger (6) is located is the first pipe section (401), and the pipe section where the battery heat exchanger (7) is located is the second pipe section (402). The first pipe section (401) and the second pipe section (402) are connected in parallel, and a first throttling device (13a) is provided on the first pipe section (401), and a second throttling device (13b) is provided on the second pipe section (402); When the ambient temperature T 环 < T 预设1 , and when the battery assembly (8) needs to be heated and heating is required inside the vehicle or indoors, control the first four-way valve (14a) so that the battery heat exchanger (7) communicates with the exhaust end of the compressor (4), and at the same time control the second four-way valve (14b) so that the battery circulation pipeline (200) and the motor circulation pipeline (300) are not in communication. The battery circulation pipeline (200) and the motor circulation pipeline (300) each form a closed loop, and control both the first throttling device (13a) and the second throttling device (13b) to be opened; When the ambient temperature T 环 > T 预设2 , and when the battery assembly (8) needs to be cooled and refrigeration is required inside the vehicle or indoors, control the first four-way valve (14a) so that the battery heat exchanger (7) communicates with the suction end of the compressor (4), and at the same time control the second four-way valve (14b) so that the battery circulation pipeline (200) and the motor circulation pipeline (300) are not communicated. The battery circulation pipeline (200) and the motor circulation pipeline (300) each form a closed loop, and control both the first throttling device (13a) and the second throttling device (13b) to be opened; When the ambient temperature T 预设1 < T 环 < T 预设2 , and when the battery assembly (8) needs to be cooled, control the second four-way valve (14b) to connect the battery circulation pipeline (200) and the motor circulation pipeline (300), so that the battery circulation pipeline (200) and the motor circulation pipeline (300) jointly form a loop. And when the vehicle external heat exchanger (1) is included, the coolant in the motor circulation pipeline releases heat in the first heat exchanger (3) and / or in the vehicle external heat exchanger (1), and control the first throttling device (13a) to open and control the second throttling device (13b) to close; When the ambient temperature T 预设1 < T 环 < T 预设2 , and when the battery assembly (8) needs to be heated, control the second four-way valve (14b) to connect the battery circulation pipeline (200) and the motor circulation pipeline (300), so that the battery circulation pipeline (200) and the motor circulation pipeline (300) jointly form a loop. And when the vehicle external heat exchanger (1) is included, the coolant in the motor circulation pipeline absorbs heat in the first heat exchanger (3), and / or absorbs heat in the vehicle external heat exchanger (1), and / or absorbs heat in the motor assembly (20), and control the first throttling device (13a) to open and control the second throttling device (13b) to close.

2. The thermal management system according to claim 1, wherein: When the battery circulation pipeline (200) and the motor circulation pipeline (300) are in communication, the battery circulation pipeline (200) and the motor circulation pipeline (300) jointly form a loop. When the battery circulation pipeline (200) and the motor circulation pipeline (300) are not in communication, the battery circulation pipeline (200) and the motor circulation pipeline (300) respectively form closed loops.

3. The thermal management system according to claim 2, wherein: The second four-way valve (14b) includes a first end (14b1), a second end (14b2), a third end (14b3) and a fourth end (14b4). The first end and the second end are respectively connected to the battery circulation pipeline (200). When the first end and the second end are connected, and the third end and the fourth end are connected, the battery circulation pipeline (200) forms a loop. When the first end and the fourth end are connected, and the second end and the third end are connected, the battery circulation pipeline (200) and the motor circulation pipeline (300) jointly form a loop.

4. The thermal management system according to claim 3, wherein: The third four-way valve (14c) includes a fifth end (14c1), a sixth end (14c2), a seventh end (14c3) and an eighth end (14c4). The fifth end (14c1) is connected to the outlet end of the second pump (12b), the sixth end (14c2) is connected to the fourth end (14b4) of the second four-way valve (14b), the seventh end (14c3) is connected to the inlet end of the second pump (12b), and the eighth end (14c4) is connected to one end of the motor assembly (20).

5. The thermal management system according to claim 1, wherein: The battery heat exchanger (7) is arranged in parallel with the second heat exchanger (6); and / or, a first pump (12a) is arranged on the battery circulation pipeline (200); and / or, the motor assembly (20) includes a charger (9), a motor controller (10) and a motor (11) which are arranged in series; and / or, a gas-liquid separator (5) is further arranged at the suction end of the compressor (4) on the heat pump circulation pipeline (100).

6. The thermal management system according to claim 5, wherein: The first pump (12a) is a water pump; and / or, the second pump (12b) is a water pump; and / or, an expansion tank (2) is further arranged on the motor circulation pipeline (300).

7. The thermal management system according to any one of claims 1-6, wherein: A first branch (403) is further arranged in parallel at a pipe section on the motor circulation pipeline (300) and between the second four-way valve (14b) and the first heat exchanger (3). An outdoor heat exchanger (1) is arranged on the first branch (403), and a three-way valve (15) is further arranged at the position where the first branch (403) is connected to the motor circulation pipeline (300).

8. A control method for a thermal management system according to any one of claims 1-7, characterized in that: When the ambient temperature T 环 < T 预设1 , and when the battery assembly (8) needs to be heated and heating is required inside the vehicle or indoors, control the first four-way valve (14a) so that the battery heat exchanger (7) communicates with the exhaust end of the compressor (4), and at the same time control the second four-way valve (14b) so that the battery circulation pipeline (200) and the motor circulation pipeline (300) are not in communication. The battery circulation pipeline (200) and the motor circulation pipeline (300) each form a closed loop, and control both the first throttling device (13a) and the second throttling device (13b) to be opened; When the ambient temperature T 环 >T 预设2 , and when the battery assembly (8) needs to be cooled and refrigeration is required inside the vehicle or indoors, control the first four-way valve (14a) to connect the battery heat exchanger (7) to the suction end of the compressor (4), and at the same time control the second four-way valve (14b) to disconnect the battery circulation pipeline (200) from the motor circulation pipeline (300). The battery circulation pipeline (200) and the motor circulation pipeline (300) each form a closed loop, and control both the first throttling device (13a) and the second throttling device (13b) to be opened; When the ambient temperature T 预设1 < T 环 < T 预设2 , and when the battery assembly (8) needs to be cooled, control the second four-way valve (14b) to connect the battery circulation pipeline (200) and the motor circulation pipeline (300), so that the battery circulation pipeline (200) and the motor circulation pipeline (300) jointly form a loop. When the vehicle external heat exchanger (1) is included, the coolant in the motor circulation pipeline releases heat in the first heat exchanger (3) and / or in the vehicle external heat exchanger (1), and control the first throttling device (13a) to open and control the second throttling device (13b) to close; When the ambient temperature T 预设1 < T 环 < T 预设2 , and when the battery assembly (8) needs to be heated, control the second four-way valve (14b) to connect the battery circulation pipeline (200) and the motor circulation pipeline (300), so that the battery circulation pipeline (200) and the motor circulation pipeline (300) jointly form a loop. And when the vehicle external heat exchanger (1) is included, the coolant in the motor circulation pipeline absorbs heat in the first heat exchanger (3), and / or absorbs heat in the vehicle external heat exchanger (1), and / or absorbs heat in the motor assembly (20), and control the first throttling device (13a) to open and control the second throttling device (13b) to close.

9. The control method according to claim 8, characterized in that: When the ambient temperature T 预设1 < T 环 < T 预设2 , and when the battery assembly (8) needs to be cooled and heating is required inside the vehicle or indoors, the first four-way valve (14a) is further controlled to connect the battery heat exchanger (7) to the exhaust end of the compressor (4), so that the refrigerant in the heat pump circulation pipeline (100) absorbs heat at the first heat exchanger (3) and releases heat at the second heat exchanger (6); When the ambient temperature T 预设1 < T 环 < T 预设2 , and when the battery assembly (8) needs to be heated and heating is required inside the vehicle or indoors, the first four-way valve (14a) is further controlled to connect the battery heat exchanger (7) to the suction end of the compressor (4), so that the refrigerant in the heat pump circulation pipeline (100) releases heat at the first heat exchanger (3) and absorbs heat at the second heat exchanger (6).

10. The control method according to claim 8, characterized in that: When the second four-way valve (14b) includes a first end (14b1), a second end (14b2), a third end (14b3) and a fourth end (14b4): When the ambient temperature T 环 < T 预设1 , and when the battery assembly (8) needs to be heated and heating is required inside the vehicle or indoors, control the first end (14b1) of the second four-way valve (14b) to communicate with the second end (14b2), and at the same time control the third end (14b3) of the second four-way valve (14b) to communicate with the fourth end (14b4); When the ambient temperature T 环 >T 预设2 , and when the battery pack (8) needs to be cooled and the vehicle interior or indoor space needs to be refrigerated, control the first end (14b1) and the second end (14b2) of the second four-way valve (14b) to communicate with each other, and at the same time control the third end (14b3) and the fourth end (14b4) of the second four-way valve (14b) to communicate with each other; When the ambient temperature T 预设1 < T 环 < T 预设2 , and when the battery assembly (8) needs to be cooled, control the first end (14b1) of the second four-way valve (14b) to communicate with the fourth end (14b4), and at the same time control the second end (14b2) of the second four-way valve (14b) to communicate with the third end (14b3); When the ambient temperature T 预设1 <T 环 <T 预设2 , and when the battery assembly (8) needs to be heated, control the first end (14b1) of the second four-way valve (14b) to communicate with the fourth end (14b4), and at the same time control the second end (14b2) of the second four-way valve (14b) to communicate with the third end (14b3).

11. The control method according to claim 8, characterized in that: When the ambient temperature T 环 < T 预设1 , and when the battery pack (8) needs to be heated and heating is required inside the vehicle or indoors, it is also controlled that the third four-way valve (14c) makes the flow direction of the refrigerant in the heat pump cycle pipeline (100) in the first heat exchanger (3) opposite to the flow direction of the coolant in the motor cycle pipeline (300); When the ambient temperature T 环 > T 预设2 , and when the battery pack (8) needs to be cooled and the vehicle interior or indoor space needs to be refrigerated, the third four-way valve (14c) is further controlled so that the flow direction of the refrigerant in the heat pump cycle pipeline (100) in the first heat exchanger (3) is opposite to the flow direction of the coolant in the motor cycle pipeline (300); When the ambient temperature T 预设1 < T 环 < T 预设2 , and when the battery assembly (8) needs to be cooled, the third four-way valve (14c) is further controlled such that the flow direction of the refrigerant in the heat pump cycle pipeline (100) in the first heat exchanger (3) is opposite to the flow direction of the coolant in the motor cycle pipeline (300); When the ambient temperature T 预设1 <T 环 <T 预设2 , and when the battery assembly (8) needs to be heated, the third four-way valve (14c) is further controlled so that the flow direction of the refrigerant in the heat pump cycle pipeline (100) in the first heat exchanger (3) is opposite to the flow direction of the coolant in the motor cycle pipeline (300).

12. The control method according to claim 11, characterized in that: When the third four-way valve (14c) includes a fifth end (14c1), a sixth end (14c2), a seventh end (14c3) and an eighth end (14c4): When the ambient temperature T 环 < T 预设1 , and when the battery pack (8) needs to be heated and heating is required inside the vehicle or indoors, control the fifth end (14c1) of the third four-way valve (14c) to communicate with the eighth end (14c4), and at the same time control the sixth end (14c2) of the third four-way valve (14c) to communicate with the seventh end (14c3); When the ambient temperature T 环 > T 预设2 , and when the battery pack (8) needs to be cooled and the vehicle interior or indoor space needs to be refrigerated, control the fifth end (14c1) of the third four-way valve (14c) to communicate with the sixth end (14c2), and at the same time control the seventh end (14c3) of the third four-way valve (14c) to communicate with the eighth end (14c4); When the ambient temperature T 预设1 < T 环 < T 预设2 , and when the battery pack (8) needs to be cooled and heating is required inside the vehicle or indoors, control the fifth end (14c1) of the third four-way valve (14c) to communicate with the eighth end (14c4), and at the same time control the sixth end (14c2) of the third four-way valve (14c) to communicate with the seventh end (14c3); When the ambient temperature T 预设1 < T 环 < T 预设2 , and when the battery assembly (8) needs to be heated and the vehicle interior or the room needs to be cooled, control the fifth end (14c1) of the third four-way valve (14c) to communicate with the sixth end (14c2), and at the same time control the seventh end (14c3) of the third four-way valve (14c) to communicate with the eighth end (14c4).

13. The control method according to any one of claims 8-12, characterized in that: When an external heat exchanger (1) and a three-way valve (15) are further included: When the ambient temperature T 环 < T 预设1 , and when the battery pack (8) needs to be heated and heating is required inside the vehicle or indoors, the three-way valve (15) is also controlled to be opened so that the external heat exchanger (1) communicates with the first heat exchanger (3), and the coolant absorbs heat from outside the vehicle in the external heat exchanger (1); When the ambient temperature T 环 > T 预设2 , and when the battery pack (8) needs to be cooled and the vehicle interior or indoor space needs to be refrigerated, control the three-way valve (15) such that the outside vehicle heat exchanger (1) communicates with the first heat exchanger (3), and the coolant releases heat to the outside of the vehicle in the outside vehicle heat exchanger (1); When the ambient temperature T 预设1 < T 环 < T 预设2 , and when the battery pack (8) needs to be cooled, control the three-way valve (15) to connect the outside vehicle heat exchanger (1) with the first heat exchanger (3), and the coolant releases heat to the outside of the vehicle in the outside vehicle heat exchanger (1); When the ambient temperature T 预设1 < T 环 < T 预设2 , and when the battery pack (8) needs to be heated, control the three-way valve (15) so that the outside vehicle heat exchanger (1) communicates with the first heat exchanger (3), and the coolant absorbs heat from outside the vehicle in the outside vehicle heat exchanger (1).

14. An electric vehicle, characterized in that: It includes the thermal management system according to any one of claims 1-7.

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