Rectangular battery direct cooling structure and thermal management control method

Abstract

The invention relates to the technical field of thermal management, in particular to a rectangular battery direct cooling structure and a thermal management control method. Comprising a frame, a direct cooling plate is fixed in the frame, rectangular batteries are evenly distributed in the direct cooling plate, flow guide pipes are fixed to the two ends of the direct cooling plate, a refrigerant inlet and a refrigerant outlet are sequentially fixed to the interior of one end of the frame from top to bottom, the refrigerant inlet is fixed to the flow guide pipe at one end, and the refrigerant outlet is fixed to the flow guide pipe at the other end; the interior of the direct cooling plate is divided into a first fixing groove and a second fixing groove, and the length ratio of the first fixing groove to the second fixing groove is 6: 4. According to the rectangular battery direct cooling structure and the thermal management control method provided by the invention, the side surface of the rectangular battery is cooled through the structure of the direct cooling plate; and meanwhile, the rectangular battery is separated through the structure of the direct cooling plate, so that local high temperature is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal management, and in particular to a direct cooling structure for rectangular batteries and a thermal management control method. Background Art

[0002] When a pure electric vehicle is driving at high speed, a large amount of heat will be released from the power battery. If these heats are not eliminated in time, the temperature of the power battery may get out of control, resulting in a battery fire accident, thus threatening the safety and property of passengers. To ensure the safety of the battery module, the temperature of the power battery should be kept as much as possible between 20 - 40 °C. At present, most new energy vehicles in China adopt a water-cooled structure, and the water-cooled structure is widely used by vehicle manufacturers because of its low price and easy availability. However, since an external water pump is required for forced cooling to provide additional kinetic energy for cooling, this will reduce the driving kinetic energy of the vehicle and greatly reduce the driving range. And most of the water-cooled structures are cooled at the level of the entire battery pack, with poor control of the temperature difference between battery modules, making it difficult to meet the requirement of a temperature difference of 5 °C, which has a relatively obvious impact on the life of the overall battery pack. And when heating the power motor in winter, the water-cooled structure has a poor heating effect and a slow temperature rise.

[0003] However, the direct cooling structure not only does not require an additional kinetic energy device, but also better controls the temperature of the battery compared to the water-cooled structure. But now most of the direct cooling plates adopt bottom cooling, which will cause a large temperature difference between the upper and lower parts of a single rectangular battery, affecting the service life of the rectangular battery.

[0004] Therefore, a direct cooling structure for rectangular batteries and a thermal management control method are designed to provide another technical solution for the above technical problems. Summary of the Invention

[0005] Based on this, it is necessary to provide a direct cooling structure for rectangular batteries and a thermal management control method to solve the technical problems raised in the above background art.

[0006] To solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A direct cooling structure for rectangular batteries includes a frame, a direct cooling plate is fixed inside the frame, rectangular batteries are evenly arranged inside the direct cooling plate, flow guide pipes are fixed at both ends of the direct cooling plate, a refrigerant inlet and a refrigerant outlet are sequentially fixed from top to bottom inside one end of the frame, the refrigerant inlet is fixed to one of the flow guide pipes, and the refrigerant outlet is fixed to the other of the flow guide pipes.

[0008] As a preferred embodiment of the direct cooling structure for rectangular batteries provided by the present invention, the inside of the direct cooling plate is divided into a first fixing groove and a second fixing groove.

[0009] As a preferred embodiment of the rectangular battery direct cooling structure provided by the present invention, the length ratio of the first fixing groove to the second fixing groove is 6:4.

[0010] A thermal management system for a rectangular battery direct cooling structure, used for any of the above, includes an environmental heat exchanger and a three-way heat exchanger. The outlet at the top of the three-way heat exchanger is connected with a third expansion valve and a fourth expansion valve through pipelines. One ends of the third expansion valve and the fourth expansion valve are connected with a cold plate through pipelines. The top end of the environmental heat exchanger is connected with a first solenoid valve through a pipeline. One end of the first solenoid valve is connected with the pipeline between the three-way heat exchanger and the third expansion valve. The bottom end of the environmental heat exchanger is connected with a third solenoid valve through a pipeline. One end of the third solenoid valve is connected with a high-voltage PTC through a pipeline. One end of the high-voltage PTC is connected with a gas-liquid separator through a pipeline. The output end of the gas-liquid separator is connected with the input end of a compressor through a pipeline. The output end of the compressor is connected with a condenser through a pipeline. One end of the condenser is connected with a first expansion valve through a pipeline. The first expansion valve is connected with the top end of the environmental heat exchanger.

[0011] As a preferred embodiment of the thermal management system for a rectangular battery direct cooling structure provided by the present invention, the outlet at the bottom of the three-way heat exchanger is connected with a driving motor through a pipeline. The bottom end of the driving motor is connected with an electronic water pump. One end of the electronic water pump is connected with a radiator. One end of the radiator is connected with a water tank through a pipeline. The water tank is connected with the bottom inlet of the three-way heat exchanger.

[0012] As a preferred embodiment of the thermal management system for a rectangular battery direct cooling structure provided by the present invention, the top inlet of the three-way heat exchanger is connected with a fifth solenoid valve through a pipeline. The fifth solenoid valve is connected with the pipeline between the high-voltage PTC and the third solenoid valve. The middle inlet of the three-way heat exchanger is connected with a fourth solenoid valve through a pipeline. The fourth solenoid valve is connected with the pipeline between the environmental heat exchanger and the third solenoid valve. The middle inlet of the three-way heat exchanger is also connected with a second solenoid valve through a pipeline. The second solenoid valve is connected with the pipeline between the condenser and the first expansion valve. The bottom of the second solenoid valve is also connected with a second expansion valve through a pipeline. One end of the second expansion valve is connected with the pipeline between the high-voltage PTC and the third solenoid valve.

[0013] A thermal management control method for a rectangular battery direct cooling structure, used for any of the above, the steps are as follows:

[0014] Start the battery high-temperature charging cooling mode;

[0015] Start the battery and occupant compartment high-temperature cooling mode;

[0016] Start the low-temperature preheating mode of the battery;

[0017] Start the low-temperature heating mode of the battery and the passenger compartment.

[0018] As a preferred embodiment of the thermal management control method for a rectangular battery direct cooling structure provided by the present invention, the steps for starting the high-temperature charging and cooling mode of the battery are as follows:

[0019] Control the opening degrees of the third expansion valve and the fourth expansion valve through the humidity at the outlet of the three-way heat exchanger to reduce the dryness at the outlet of the cold plate;

[0020] The steps for starting the high-temperature cooling mode of the battery and the passenger compartment are as follows:

[0021] Control the opening degree of the second expansion valve through the temperature of the passenger compartment, and control the opening degrees of the third expansion valve and the fourth expansion valve through the dryness at the outlet of the three-way heat exchanger.

[0022] As a preferred embodiment of the thermal management control method for a rectangular battery direct cooling structure provided by the present invention, the steps for starting the low-temperature preheating mode of the battery are as follows:

[0023] Control the rotation speed of the compressor to keep the temperature difference between the high-temperature saturation temperature of the refrigerant gas and the battery at 15°C;

[0024] Control the opening degrees of the third expansion valve and the fourth expansion valve by controlling the superheat degree and the dryness at the outlet of the cold plate;

[0025] If the superheat degree at the outlet is greater than 3°C, increase the opening degree of the fourth expansion valve, and cool the refrigerant state to saturation before entering the cold plate;

[0026] If the ambient temperature is lower than 10°C, turn on the high-voltage PTC for auxiliary heating;

[0027] The steps for starting the low-temperature heating mode of the battery and the passenger compartment are as follows:

[0028] If the ambient temperature is lower than 10°C, the refrigerant does not pass through the ambient heat exchanger. After the refrigerant heats the power battery, it passes through the third expansion valve, the three-way heat exchanger, and then passes through the high-voltage PTC for heating and enters the gas-liquid separator and then returns to the compressor.

[0029] It can be undoubtedly seen that through the above technical solutions of the present application, the technical problems to be solved by the present application can surely be solved.

[0030] At the same time, through the above technical solutions, the present invention has at least the following beneficial effects:

[0031] 1. A direct cooling structure for rectangular batteries and a thermal management control method provided by the present invention cool the rectangular batteries laterally through the structure of the direct cooling plate; at the same time, the rectangular batteries are separated through the structure of the direct cooling plate, so as to avoid the occurrence of local high temperature, increase the contact area between the rectangular batteries and the direct cooling plate, thereby reducing the temperature difference between the upper and lower parts of a single rectangular battery. At the same time, separating the rectangular batteries can avoid the occurrence of local high temperature caused by the mutual contact of the rectangular batteries.

[0032] 2. The present invention can well fix a single rectangular battery through the structure of the direct cooling plate, thereby avoiding structural damage to the battery caused by long-term vibration.

[0033] 3. The present invention adopts a design with a larger upper part and a smaller lower part for the flow channel to further ensure the temperature uniformity of the rectangular battery, thereby preventing uneven heating of the upper and lower parts of the rectangular battery, resulting in more serious heating of the upper half of the rectangular battery compared to the lower half.

[0034] 4. The present invention controls the refrigeration and heating of the battery and the passenger compartment through the thermal management system, improving the endurance of new energy vehicles. Thus, it not only cools the battery and the passenger compartment in summer, but also can realize the heating of the battery and the passenger compartment in winter through the design of the thermal management system, improving the driving mileage of new energy vehicles in winter. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0036] Figure 1 It is a schematic diagram of the overall framework of the present invention;

[0037] Figure 2 It is an overall view of the direct cooling of rectangular batteries of the present invention;

[0038] Figure 3 It is a detailed view of the direct cooling plate of the present invention;

[0039] Figure 4 It is a flow direction diagram of the direct cooling plate of the present invention.

[0040] In the figure: 1. Compressor; 2. Condenser; 3. Ambient heat exchanger; 4. Three-way heat exchanger; 5. Cold plate; 6. High-voltage PTC; 7. Gas-liquid separator; 8. Driving motor; 9. Electronic water pump; 10. Radiator; 11. Water tank; 12. First expansion valve; 13. Second expansion valve; 14. Third expansion valve; 15. Fourth expansion valve; 16. Solenoid valve 1; 17. Solenoid valve 2; 18. Solenoid valve 3; 19. Solenoid valve 4; 20. Solenoid valve 5; 21. Rectangular battery; 22. Frame; 23. Direct cold plate; 24. Refrigerant inlet; 25. Refrigerant outlet. Specific embodiments

[0041] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0042] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings.

[0043] It should be noted that, without conflict, the embodiments in the present invention and the features and technical solutions in the embodiments can be combined with each other.

[0044] It should be noted that similar reference numerals and letters indicate similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0045] Embodiment 1

[0046] Referring to Figures 2 - 4 , a direct cooling structure for a rectangular battery, the direct cooling structure includes a frame 22, a direct cold plate 23 is fixed inside the frame 22, rectangular batteries 21 are evenly arranged inside the direct cold plate 23, so as to fix the rectangular batteries 21 through a plurality of direct cold plates 23 and separate adjacent rectangular batteries 21. Guide pipes are fixed at both ends of the direct cold plate 23. Inside one end of the frame 22, a refrigerant inlet 24 and a refrigerant outlet 25 are sequentially fixed from top to bottom. The refrigerant inlet 24 is fixed to one of the guide pipes, and the refrigerant outlet 25 is fixed to the other of the guide pipes. Furthermore, the inlet and outlet circulation of the refrigerant can be realized through the refrigerant inlet 24 and the refrigerant outlet 25. After the refrigerant enters through the refrigerant inlet 24, it flows inside the guide pipe and then enters the inside of the refrigerant outlet 25 and is discharged. For the specific flow of the refrigerant inside the guide pipe, reference can be made to Figure 3 and Figure 4 .

[0047] In this embodiment, the interior of the direct cooling plate 23 is divided into a first fixing groove and a second fixing groove. The length ratio of the first fixing groove to the second fixing groove is 6:4, so that the direct cooling plate 23 adopts a design with a larger upper part and a smaller lower part, thereby better performing thermal management on the rectangular battery 21.

[0048] The usage process of a rectangular battery direct cooling structure provided by the present invention is as follows: during use, refrigerant is allowed to enter the interior of the refrigerant inlet 24, and enters the interior of the diversion pipe inside the refrigerant inlet 24. After flowing inside the diversion pipe, thermal management is performed on the rectangular battery 21, and then it is discharged through the refrigerant outlet 25.

[0049] Embodiment 2

[0050] Reference Figure 1 , on the basis of the above-mentioned Embodiment 1, it is disclosed that it includes an environmental heat exchanger 3 and a three-way heat exchanger 4. The outlet at the top of the three-way heat exchanger 4 is connected with a third expansion valve 14 and a fourth expansion valve 15 through a pipeline. One ends of the third expansion valve 14 and the fourth expansion valve 15 are connected with a cold plate 5 through a pipeline, so that the opening degrees of the third expansion valve 14 and the fourth expansion valve 15 can be controlled by the humidity at the outlet of the three-way heat exchanger 4 to reduce the dryness at the outlet of the cold plate 5. The outlet at the bottom of the three-way heat exchanger 4 is connected with a driving motor 8 through a pipeline. The bottom end of the driving motor 8 is connected with an electronic water pump 9. One end of the electronic water pump 9 is connected with a radiator 10. A fan is arranged at the top of the radiator 10, so that the radiator 10 can be dissipated heat by the fan. One end of the radiator 10 is connected with a water tank 11 through a pipeline, and the water tank 11 is connected with the bottom inlet of the three-way heat exchanger 4;

[0051] The top end of the environmental heat exchanger 3 is connected with a first solenoid valve 16 through a pipeline. One end of the first solenoid valve 16 is connected with the pipeline between the three-way heat exchanger 4 and the third expansion valve 14. The bottom end of the environmental heat exchanger 3 is connected with a third solenoid valve 18 through a pipeline, so that the output of the environmental heat exchanger 3 enters the third solenoid valve 18. One end of the third solenoid valve 18 is connected with a high-voltage PTC 6 through a pipeline. One end of the high-voltage PTC 6 is connected with a gas-liquid separator 7 through a pipeline. The output end of the gas-liquid separator 7 is connected with the input end of the compressor 1 through a pipeline. The output end of the compressor 1 is connected with a condenser 2 through a pipeline, so that the refrigerant can enter the condenser 2 after being compressed by the compressor 1. One end of the condenser 2 is connected with a first expansion valve 12 through a pipeline, and the first expansion valve 12 is connected with the top end of the environmental heat exchanger 3;

[0052] Preferably, the top inlet of the three-way heat exchanger 4 is connected with a fifth solenoid valve 20 through a pipeline, and the fifth solenoid valve 20 is connected with the pipeline between the high-voltage PTC 6 and the third solenoid valve 18;

[0053] Preferably, a fourth solenoid valve 19 is connected to the middle inlet of the three-way heat exchanger 4 through a pipeline. The fourth solenoid valve 19 is connected to the pipeline between the environmental heat exchanger 3 and the third solenoid valve 18. The middle inlet of the three-way heat exchanger 4 is also connected to a second solenoid valve 17 through a pipeline. The second solenoid valve 17 is connected to the pipeline between the condenser 2 and the first expansion valve 12;

[0054] Preferably, the bottom of the second solenoid valve 17 is also connected to a second expansion valve 13 through a pipeline. One end of the second expansion valve 13 is connected to the pipeline between the high-voltage PTC 6 and the third solenoid valve 18;

[0055] Preferably, an environmental heat exchanger 3 is also provided at one end of the second expansion valve 13 close to the high-voltage PTC 6.

[0056] Embodiment III

[0057] Based on the above Embodiment I and Embodiment II, a thermal management control method for a rectangular battery direct cooling structure is disclosed, and the steps are as follows:

[0058] Mode 1: Battery high-temperature charging cooling

[0059] In this mode, the first expansion valve 12, the third expansion valve 14, and the fourth expansion valve 15 are opened, the second expansion valve 13 is closed, the first solenoid valve 16, the second solenoid valve 17, and the third solenoid valve 18 are closed, and the fourth solenoid valve 19 and the fifth solenoid valve 20 are opened. After the refrigerant is pressurized by the compressor 1, it passes through the condenser 2 (without heat exchange with air at this time), the first expansion valve 12, the environmental heat exchanger 3, the fourth solenoid valve 19, and then enters the cold plate 5 for battery cooling after the pressure reduction by the three-way heat exchanger 4 and the fourth expansion valve 15. Then it passes through the third expansion valve 14, the three-way heat exchanger 4, the fifth solenoid valve 20, the high-voltage PTC 6, and the gas-liquid separator 7 and returns to the compressor 1, thus completing a cooling cycle.

[0060] In this mode, the opening degrees of the third expansion valve 14 and the fourth expansion valve 15 are controlled by the humidity at the outlet of the three-way heat exchanger 4 to reduce the dryness at the outlet of the cold plate 5, so as to obtain better temperature uniformity of the power battery.

[0061] Mode 2: Battery and occupant compartment high-temperature cooling

[0062] In this mode, the first expansion valve 12, the second expansion valve 13, the third expansion valve 14, and the fourth expansion valve 15 are opened, the first solenoid valve 16, the second solenoid valve 17, and the third solenoid valve 18 are closed, and the fourth solenoid valve 19 and the fifth solenoid valve 20 are opened. After the refrigerant is pressurized by the compressor 1, it passes through the condenser 2 (without heat exchange with air at this time), the first expansion valve 12, the ambient heat exchanger 3, the fourth solenoid valve 19, and the three-way heat exchanger 4. Then, a part of it flows into the second expansion valve 13 to be depressurized and then enters the evaporator to cool the passenger compartment. After passing through the high-voltage PTC 6 and the gas-liquid separator 7, it enters the compressor 1; another part of the refrigerant passes through the fourth expansion valve 15 to be depressurized and then enters the cold plate 5 to cool the power battery. After passing through the third expansion valve 14, the three-way heat exchanger 4, the fifth solenoid valve 20, the high-voltage PTC 6, and the gas-liquid separator 7, it returns to the compressor 1, thus completing a cooling cycle.

[0063] In this mode, the second expansion valve 13 controls the opening degree according to the temperature of the passenger compartment. The third expansion valve 14 and the fourth expansion valve 15 control their opening degrees according to the dryness at the outlet of the three-way heat exchanger 4.

[0064] Mode 3: Low-temperature preheating of the battery

[0065] In this mode, the first expansion valve 12 and the second expansion valve 13 are closed, and the third expansion valve 14 and the fourth expansion valve 15 are opened. The first solenoid valve 16, the second solenoid valve 17, and the third solenoid valve 18 are opened, and the fourth solenoid valve 19 and the fifth solenoid valve 20 are closed. After the refrigerant is pressurized by the compressor 1, it passes through the condenser 2 (without heat exchange with air at this time), the second solenoid valve 17, and the fourth expansion valve 15 and enters the cold plate 5 to heat the power battery. After passing through the third expansion valve 14, the first solenoid valve 16, the ambient heat exchanger 3, the third solenoid valve 18, the high-voltage PTC 6, and the gas-liquid separator 7, it enters the compressor 1, thus completing a heating cycle.

[0066] In this mode, the rotation speed of the compressor 1 controls the temperature difference between the high-temperature saturation temperature of the refrigerant gas and the battery to be kept at 15°C. The opening degrees of the third expansion valve 14 and the fourth expansion valve 15 are controlled by controlling the superheat degree and the dryness at the outlet of the cold plate 5. When the superheat degree at the outlet is greater than 3°C, the opening degree of the fourth expansion valve 15 should be increased, and before entering the cold plate 5, the refrigerant state should be cooled to saturation. In this mode, if the ambient temperature is lower than 10°C, heat exchange is carried out with the motor water-cooling system through the three-way heat exchanger 4. If the ambient temperature is lower than -10°C, the high-voltage PTC 6 should be turned on for auxiliary heating.

[0067] Mode 4: Low-temperature heating of the battery and the passenger compartment

[0068] In this mode, the first expansion valve 12 is closed, and the second expansion valve 13, the third expansion valve 14, and the fourth expansion valve 15 are opened. The first solenoid valve 16, the second solenoid valve 17, and the third solenoid valve 18 are opened, and the fourth solenoid valve 19 and the fifth solenoid valve 20 are closed. After the refrigerant is pressurized by the compressor 1, it passes through the condenser 2 to heat the passenger compartment, and then passes through the second solenoid valve 17, the three-way heat exchanger 4, and the fourth expansion valve 15 to enter the cold plate 5 to heat the power battery. It passes through the third expansion valve 14, the first solenoid valve 16, the ambient heat exchanger 3, the third solenoid valve 18, the high-voltage PTC 6, and the gas-liquid separator 7 and enters the compressor 1, thus completing a complete one-time heating cycle.

[0069] In this mode, the temperature of the passenger compartment is controlled by controlling the fan in front of the condenser 2. The rotational speed of the compressor 1 controls the temperature difference between the high-temperature saturation temperature of the refrigerant gas and the battery to be maintained at 15°C. By controlling the superheat degree and dryness at the outlet of the cold plate 5, the opening degrees of the third and fourth expansion valves 15 are controlled. When the superheat degree at the outlet is greater than 3°C, the opening degree of the fourth expansion valve 15 should be increased, and before entering the cold plate 5, the refrigerant state should be cooled to saturation. In this mode, if the ambient temperature is lower than 10°C, heat exchange is carried out with the motor water-cooling system through the three-way heat exchanger 4. If the ambient temperature is lower than -10°C, the refrigerant does not pass through the ambient heat exchanger 3. After the refrigerant heats the power battery, it passes through the third expansion valve 14, the three-way heat exchanger 4, and then is heated by the high-voltage PTC 6 and enters the gas-liquid separator 7 and then returns to the compressor 1. In this case, the power of the high-voltage PTC 6 is determined by measuring the temperature of the battery.

[0070] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principle and practical application of the present invention, so that those skilled in the art can understand and utilize the present invention well. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A direct cooling structure for a rectangular battery, characterized in that It includes a frame (22), a direct cooling plate (23) is fixedly arranged inside the frame (22), rectangular batteries (21) are evenly arranged inside the direct cooling plate (23), flow guiding pipes are fixedly arranged at both ends of the direct cooling plate (23), a refrigerant inlet (24) and a refrigerant outlet (25) are fixedly arranged inside one end of the frame (22) from top to bottom in sequence, the refrigerant inlet (24) is fixed to one of the flow guiding pipes, and the refrigerant outlet (25) is fixed to the other of the flow guiding pipes.

2. The direct cooling structure of a rectangular battery according to claim 1, characterized in that The inside of the direct cooling plate (23) is divided into a first fixing groove and a second fixing groove.

3. The direct cooling structure of a rectangular battery according to claim 2, wherein The length ratio of the first fixing groove to the second fixing groove is 6:

4.

4. A thermal management system for a direct liquid cooling structure of a rectangular battery, which is used for the direct liquid cooling structure of a rectangular battery according to any one of claims 1-3, characterized in that, It includes an environmental heat exchanger (3) and a three-way heat exchanger (4). The outlet at the top of the three-way heat exchanger (4) is connected with a third expansion valve (14) and a fourth expansion valve (15) through a pipeline. One ends of the third expansion valve (14) and the fourth expansion valve (15) are connected with a cold plate (5) through a pipeline. The top end of the environmental heat exchanger (3) is connected with a first solenoid valve (16) through a pipeline. One end of the first solenoid valve (16) is connected with the pipeline between the three-way heat exchanger (4) and the third expansion valve (14). The bottom end of the environmental heat exchanger (3) is connected with a third solenoid valve (18) through a pipeline. One end of the third solenoid valve (18) is connected with a high-voltage PTC (6) through a pipeline. One end of the high-voltage PTC (6) is connected with a gas-liquid separator (7) through a pipeline. The output end of the gas-liquid separator (7) is connected with the input end of a compressor (1) through a pipeline. The output end of the compressor (1) is connected with a condenser (2) through a pipeline. One end of the condenser (2) is connected with a first expansion valve (12) through a pipeline. The first expansion valve (12) is connected with the top end of the environmental heat exchanger (3).

5. The thermal management system of a rectangular battery direct cooling structure according to claim 4, characterized in that, The outlet at the bottom of the three-way heat exchanger (4) is connected with a drive motor (8) through a pipeline. The bottom end of the drive motor (8) is connected with an electronic water pump (9). One end of the electronic water pump (9) is connected with a radiator (10). One end of the radiator (10) is connected with a water tank (11) through a pipeline. The water tank (11) is connected with the bottom inlet of the three-way heat exchanger (4).

6. The thermal management system of a rectangular battery direct cooling structure according to claim 4, characterized in that, The top inlet of the three-way heat exchanger (4) is connected with a fifth solenoid valve (20) through a pipeline. The fifth solenoid valve (20) is connected with the pipeline between the high-voltage PTC (6) and the third solenoid valve (18). The middle inlet of the three-way heat exchanger (4) is connected with a fourth solenoid valve (19) through a pipeline. The fourth solenoid valve (19) is connected with the pipeline between the environmental heat exchanger (3) and the third solenoid valve (18). The middle inlet of the three-way heat exchanger (4) is also connected with a second solenoid valve (17) through a pipeline. The second solenoid valve (17) is connected with the pipeline between the condenser (2) and the first expansion valve (12). The bottom of the second solenoid valve (17) is also connected with a second expansion valve (13) through a pipeline. One end of the second expansion valve (13) is connected with the pipeline between the high-voltage PTC (6) and the third solenoid valve (18).

7. A thermal management control method for a direct cooling structure of a rectangular battery, which is used for the direct cooling structure of a rectangular battery according to any one of claims 4-6, characterized in that, The steps are as follows: Start the high-temperature charging and cooling mode of the battery; Start the high-temperature cooling mode of the battery and the occupant compartment; Start the low-temperature preheating mode of the battery; Start the low-temperature heating mode of the battery and the occupant compartment.

8. A thermal management control method for a direct cooling structure of a rectangular battery according to claim 7, characterized in that The steps for starting the high-temperature charging and cooling mode of the battery are as follows: Control the opening degrees of the humidity control third expansion valve (14) and the fourth expansion valve (15) at the outlet of the three-way heat exchanger (4) to reduce the dryness at the outlet of the cold plate (5); The steps for starting the high-temperature cooling mode of the battery and the occupant compartment are as follows: Control the opening degree of the second expansion valve (13) through the temperature of the occupant compartment, and control the opening degrees of the third expansion valve (14) and the fourth expansion valve (15) through the dryness at the outlet of the three-way heat exchanger (4).

9. A thermal management control method for a direct cooling structure of a rectangular battery according to claim 7, characterized in that, The steps for starting the low-temperature preheating mode of the battery are as follows: Control the rotation speed of the compressor (1) to keep the temperature difference between the high-temperature saturation temperature of the refrigerant gas and the battery at 15 °C; Control the opening degrees of the third expansion valve (14) and the fourth expansion valve (15) by controlling the superheat degree and the outlet dryness at the outlet of the cold plate (5); If the outlet superheat degree is greater than 3 °C, increase the opening degree of the fourth expansion valve (15), and cool the refrigerant state to saturation before entering the cold plate (5); If the ambient temperature is lower than 10 °C, turn on the high-voltage PTC (6) for auxiliary heating; The steps for starting the low-temperature heating mode of the battery and the occupant compartment are as follows: If the ambient temperature is lower than 10 °C, the refrigerant does not pass through the ambient heat exchanger (3), and after heating the power battery, the refrigerant passes through the third expansion valve (14), the three-way heat exchanger (4), and then passes through the high-voltage PTC (6) for heating and enters the gas-liquid separator (7) and then returns to the compressor (1).

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