Electric mine truck battery thermal management system and control method thereof

Abstract

The application discloses a kind of electric mine truck battery thermal management system and its control method, it is related to thermal management technical field, including multiple general thermal management unit and shared vehicle end radiator, each unit includes battery coolant side, water-cooled condenser coolant side and refrigerant side.Battery coolant side is equipped with five-way water valve, battery water pump, high-pressure heater and water temperature sensor;Water-cooled condenser coolant side is indirectly heat-exchanged with battery coolant side by water-water heat exchanger, and each unit water-cooled condenser is connected in parallel into radiator loop.Control method includes: when ambient temperature is higher than 5 DEG C and battery pack has refrigeration demand, enter high-temperature refrigeration mode;When ambient temperature is lower than 5 DEG C and battery pack has refrigeration demand, enter low-temperature refrigeration mode;When battery pack has heating demand, enter heating mode.The application supports modular flexible expansion, significantly energy saving and prolonging life by reducing compressor operating time, and prevents impurities from blocking battery flow channel by using indirect heat exchange, improves system reliability.

Description

Technical Field

[0001] This invention relates to the field of thermal management technology, and in particular to a thermal management system for electric mining truck batteries and its control method. Background Technology

[0002] Electric mining trucks have huge power battery capacities (often exceeding 1000 kWh) and are usually composed of multiple independent battery packs. Each battery pack requires a separate thermal management unit for temperature control, so multiple thermal management units need to be configured.

[0003] Existing systems often use compressors for active cooling. Even in low-temperature environments, where the battery only requires minimal heat dissipation, the compressor still needs to be started, leading to high energy consumption, frequent equipment start-ups and shutdowns, and severely shortening the compressor's lifespan.

[0004] In addition, in the existing technology, if the coolant on the radiator side directly enters the battery pack, it is easy to introduce impurities that can cause microchannel blockage, resulting in poor safety. Moreover, each unit is mostly a customized structure, which cannot be flexibly expanded according to the number of battery packs, resulting in poor versatility and low system integration. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing an electric mining truck battery thermal management system and its control method.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: An electric mining truck battery thermal management system includes multiple parallel-connected general thermal management units and a shared vehicle-end radiator; Each of the general thermal management units includes a battery coolant side, a water-cooled condenser coolant side, and a refrigerant side; The battery coolant side includes a battery water pump, a five-way water valve, a cooler, and a high-pressure heater connected in a pipeline between the battery pack inlet and outlet, as well as a water temperature sensor for detecting the temperature of the inlet and outlet water of the battery; the five-way water valve has five interfaces A, B, C, D, and E, which are used to adjust the coolant flow direction by switching the interface connection status; The coolant side of the water-cooled condenser includes a water-cooled condenser, and the inlet and outlet of the water-cooled condenser are respectively connected to the outlet and inlet of the vehicle-end radiator. The refrigerant side includes a compressor, a water-cooled condenser, a liquid receiver-drier, an expansion valve, and a cooler connected in sequence by pipelines to form a refrigeration cycle loop; It also includes a water-to-water heat exchanger, through which the water passage on the battery coolant side and the water passage on the coolant side of the water-cooled condenser exchange heat indirectly. The water outlets of the water-cooled condensers of each of the general thermal management units converge and are connected to the inlet of the vehicle-end radiator via a radiator water pump. The water outlets of the vehicle-end radiators are then split and connected to the inlets of each of the water-cooled condensers.

[0007] Furthermore, the five-way water valve has at least three operating modes: Mode 1: AD connected, CB connected, E closed; Mode 2: CD is connected, AB is connected, and E is closed. Mode 3: CB connected, CE connected, A closed, D closed.

[0008] Furthermore, the battery coolant side is also connected to an exhaust and replenishment assembly, including a replenishment port connected to the battery water pump inlet and an exhaust port connected to the highest point of the cooling circuit. Each of the general thermal management units is equipped with an independent expansion tank, and the vehicle-end radiator is matched with an independent expansion tank.

[0009] Furthermore, the refrigerant side is also equipped with a high-pressure PT sensor and a low-pressure PT sensor. The high-pressure PT sensor is installed in the pipeline between the compressor exhaust port and the water-cooled condenser, and the low-pressure PT sensor is installed in the pipeline between the cooler outlet and the compressor.

[0010] Furthermore, the compressor is a general-purpose electric scroll compressor that uses R134a or R1234yf refrigerant. Both the water-cooled condenser and the cooler are plate heat exchangers. The expansion valve is a thermostatic expansion valve, an electronic expansion valve, or an electromagnetic expansion valve.

[0011] A control method based on the electric mining truck battery thermal management system includes the following steps: When the ambient temperature is higher than 5°C and the battery pack requires cooling, the control unit enters the high-temperature cooling mode. When the ambient temperature is below 5°C and the battery pack requires cooling, the control unit enters the low-temperature cooling mode. When the battery pack requires heating, the control unit enters heating mode. Furthermore, in the high-temperature cooling mode: Set the five-way water valve to mode one, start the compressor, and turn off the high-pressure heater; The compressor frequency is adjusted based on the battery inlet water temperature, which is set at 25℃ and controlled within the range of 10℃-30℃. The expansion valve is controlled to perform closed-loop regulation based on the superheat at the cooler outlet, with the target superheat set at 10-15℃. The duty cycle of the radiator fan and radiator water pump is adjusted by referring to a table based on the maximum value of the high-pressure PT sensor of each unit. The higher the pressure, the larger the duty cycle. Control the battery water pump to operate at a fixed duty cycle to meet flow requirements.

[0012] Furthermore, in the aforementioned low-temperature refrigeration mode: Set the five-way water valve to mode two to shut down the compressor and high-pressure heater. The battery coolant is controlled to exchange heat indirectly with the coolant side of the water-cooled condenser through a water-to-water heat exchanger, and passive heat dissipation is achieved using the vehicle-end radiator. The duty cycle of the radiator fan and radiator water pump is adjusted by referring to a table based on the battery inlet water temperature; the higher the temperature, the larger the duty cycle. Control the battery water pump to operate at a fixed duty cycle to meet flow requirements.

[0013] Furthermore, in the heating mode: Set the five-way water valve to mode three, turn off the compressor and refrigerant side, and turn off the radiator fan and radiator water pump; The water outlet of the battery is controlled to be split through a five-way water valve. Part of the water flows through a high-pressure heater for heating, and the other part flows through a bypass pipeline. The two streams are mixed and then sent back to the battery pack by the battery water pump. The heating power of the high-pressure heater is adjusted to target the battery inlet water temperature, which is set at 50°C. Control the battery water pump to operate at a fixed duty cycle to meet flow requirements.

[0014] Furthermore, in mode three, the flow area ratio of the five-way water valve from port C to port B and from port C to port E is controlled at 50%:50%. Furthermore, the battery thermal management unit system is configured with a corresponding number of general thermal management units according to the number of battery packs. Each unit independently controls its corresponding battery pack, and the water-cooled condenser side of each unit is connected in parallel to the shared vehicle-end radiator circuit.

[0015] Compared with the prior art, the beneficial effects of the present invention are: (1) The present invention is equipped with a universal thermal management unit. Each unit shares the vehicle-end radiator and each unit provides cold and hot water to the battery pack separately. The number of units can be flexibly increased or decreased according to capacity requirements. It has strong universality and strong modular expandability. (2) The present invention is equipped with a five-way water valve on the coolant side. By switching the mode through the five-way water valve, the battery can achieve high-temperature cooling, low-temperature passive cooling and active heating functions. In low-temperature environment, passive cooling is carried out by natural cold source, which greatly reduces the compressor running time, reduces energy consumption and extends its life. (3) The present invention utilizes a water-to-water heat exchanger to achieve physical isolation between the battery and the coolant on the radiator side. The coolant of the water-cooled condenser and the coolant of the battery exchange heat indirectly through the water-to-water heat exchanger, preventing impurities from the radiator from entering the battery pack and causing blockage of the flow channel, thereby improving system safety. Attached Figure Description

[0016] Figure 1 This is a schematic diagram illustrating the connection principle of the shared radiator for each unit in an embodiment of the present invention; Figure 2 This is a schematic diagram of the thermal management unit in an embodiment of the present invention; Figure 3 This is a schematic diagram of the thermal management unit in working mode one of the embodiments of the present invention; Figure 4 This is a schematic diagram of the thermal management unit in working mode two of this embodiment of the invention; Figure 5 This is a schematic diagram of the thermal management unit in working mode three of this embodiment of the invention.

[0017] In the diagram: 11. Unit 1; 12. Unit 2; 13. Unit 3; 14. Unit 4; 15. Unit 5; 16. Unit 6; 17. Unit 7; 18. Unit 8; 19. First battery pack; 110. Second battery pack; 111. Third battery pack; 112. Fourth battery pack; 113. Fifth battery pack; 114. Sixth battery pack; 115. Seventh battery pack; 116. Eighth battery pack; 117. First expansion tank; 118. Second expansion tank; 119. Third expansion tank; 120. Fourth expansion tank; 121. Fifth expansion tank; 122. Sixth expansion tank; 123. Seventh expansion tank; 124. Eighth expansion tank; 125. Radiator; 126. Fan; 127. Radiator water pump; 128. Radiator expansion tank; 21. Five-way water valve; 22. Battery water pump; 23. High-pressure heater; 24. Inlet water temperature sensor; 25. Outlet water temperature sensor; 26. Battery inlet; 27. Battery outlet; 28. Water-cooled condenser inlet; 29. ​​Water-cooled condenser outlet; 210. Liquid replenishment port; 211. Exhaust port; 212. Water-to-water heat exchanger; 213. Compressor; 214. Water-cooled condenser; 215. Liquid storage and drying tank; 216. Cooler; 217. Expansion valve; 218. High-pressure PT sensor; 219. Low-pressure PT sensor. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0019] This invention provides a battery thermal management system and its control method suitable for multi-battery-pack vehicles such as electric mining trucks.

[0020] like Figure 1 As shown, the system matches a corresponding number of universal thermal management units based on the number of battery packs. This embodiment provides a system including eight universal thermal management units, capable of meeting the needs of electric mining trucks with a total power exceeding 1000 kWh or even reaching 3000 kWh. The eight units are designated as Unit 11, Unit 22, Unit 33, Unit 44, Unit 515, Unit 616, Unit 717, and Unit 818. Each unit corresponds to an independent battery pack, namely Battery Pack 19, Battery Pack 110, etc. The third battery pack 111, the fourth battery pack 112, the fifth battery pack 113, the sixth battery pack 114, the seventh battery pack 115, and the eighth battery pack 116 are connected to the corresponding battery pack through their respective battery water inlet pipe and battery water outlet pipe. Each unit has its own expansion tank for replenishing liquid and venting liquid, namely the first expansion tank 117, the second expansion tank 118, the third expansion tank 119, the fourth expansion tank 120, the fifth expansion tank 121, the sixth expansion tank 122, the seventh expansion tank 123, and the eighth expansion tank 124.

[0021] Furthermore, all units are cooled by a shared vehicle-end radiator 125, enabling modular expansion and independent control. The radiator 125 is equipped with a fan 126.

[0022] Each unit includes a coolant side and a refrigerant side. The coolant side includes the battery coolant side and the water-cooled condenser coolant side.

[0023] like Figure 2 As shown, the battery coolant side includes a five-way water valve 21, a battery water pump 22, a high-pressure heater 23, an inlet water temperature sensor 24 and an outlet water temperature sensor 25, a battery inlet 26 and a battery outlet 27.

[0024] Specifically, the battery water pump 22 is used to drive the circulation of coolant and is connected to the pipeline between the battery inlet and outlet.

[0025] The high-pressure heater 23 is used to heat the battery and is connected to the battery water pump 22 and the five-way water valve 21.

[0026] The five-way water valve 21 has five ports: A, B, C, D, and E. Different combinations of these ports allow for adjustment of the coolant flow direction. The five-way water valve 21 has three modes: Mode 1, Mode 2, and Mode 3. In Mode 1, the flow path is: AD, CB, E closed; in Mode 2, the flow path is: CD, AB, E; and in Mode 3, the flow path is: CB\E, A, D.

[0027] The inlet water temperature sensor 24 and the outlet water temperature sensor 25 are respectively installed on the inlet and outlet water pipes between the battery inlet 26 and the battery water pump 22 to detect the inlet and outlet water temperatures of the battery.

[0028] Combination Figure 1 The coolant side of the water-cooled condenser includes a water-cooled condenser inlet 28 and a water-cooled condenser outlet 29. The water-cooled condenser inlet 28 is used to connect to the outlet of the radiator 125, and the water-cooled condenser outlet 29 is used to connect to the inlet of the radiator 125.

[0029] The outlet pipes of each unit's water-cooled condenser are connected to the outlets of other units. The water is driven by the radiator pump 127 to enter the radiator 125 for heat dissipation. The water outlet of the radiator 125 is split and connected to the inlet 28 of each water-cooled condenser by the water-cooled condenser inlet pipe. The radiator 125 is equipped with a radiator expansion tank 128 for replenishing liquid and venting.

[0030] The battery coolant side also includes an exhaust and replenishment side. The replenishment port 210 of the exhaust and replenishment side is connected to the inlet of the battery water pump 22 and is used to replenish the system with coolant or store excess coolant. The exhaust port 211 of the exhaust and replenishment side is connected to the highest point of the battery coolant side and the expansion tank and is used to expel gas from the system.

[0031] The battery coolant and the water-cooled condenser coolant exchange heat through the water-to-water heat exchanger 212, achieving indirect heat exchange and avoiding direct interaction of the coolants.

[0032] The refrigerant side includes a compressor 213, a water-cooled condenser 214, a liquid receiver-drier 215, a cooler 216, an expansion valve 217, a high-pressure PT sensor 218, and a low-pressure PT sensor 219.

[0033] Specifically, compressor 213 compresses low-pressure gaseous refrigerant into high-pressure gaseous refrigerant, with its inlet connected to the low-pressure side of cooler 216 and its outlet connected to water-cooled condenser 214.

[0034] The water-cooled condenser 214 is a plate heat exchanger that condenses the high-pressure gaseous refrigerant into liquid refrigerant and transfers heat to the coolant for heat dissipation. Its inlet is connected to the compressor 213 and its outlet is connected to the liquid storage and drying tank 215.

[0035] The liquid storage drying tank 215 is placed between the water-cooled condenser 214 and the electronic expansion valve 217, and is used to store excess refrigerant and absorb moisture in the refrigerant.

[0036] Expansion valve 217 throttles the high-pressure liquid refrigerant into a low-pressure gas-liquid two-phase refrigerant. Its inlet is connected to the liquid storage and drying tank 215, and its outlet is connected to the cooler 216.

[0037] Cooler 216 is a plate heat exchanger that allows the gas-liquid two-phase refrigerant formed after throttling to absorb heat from the water side and evaporate into a superheated gaseous state. Its inlet is connected to expansion valve 217 and its outlet is connected to compressor 213.

[0038] The high-pressure PT sensor 218 monitors the exhaust temperature and pressure of the compressor 213 and is installed on the pipeline between the exhaust port of the compressor 213 and the water-cooled condenser 214 to protect the high-pressure side of the system.

[0039] The low-pressure PT sensor 219 monitors the outlet temperature and pressure of the cooler 216 and is installed on the pipeline between the outlet of the cooler 216 and the compressor 213 to protect the low-pressure side of the system.

[0040] It should be noted that all pipelines in this embodiment are not shown in the figure.

[0041] The working mode and control process of this application are as follows: Work Mode 1, such as Figure 3 As shown, when the ambient temperature is higher than 5°C and the battery pack requires cooling, the system enters the battery high-temperature cooling mode.

[0042] On the refrigerant side, compressor 213 draws in low-temperature, low-pressure refrigerant flowing out from the low-pressure side of cooler 216, compresses it, and discharges it to water-cooled condenser 214. The water-cooled condenser 214 transfers heat to the coolant side. The refrigerant flowing out of water-cooled condenser 214 is stored in liquid storage and drying tank 215 and then throttled by expansion valve 217. The two-phase refrigerant enters cooler 216, absorbs heat from the battery coolant side to cool the battery pack, and the refrigerant flowing out of cooler 216 returns to compressor 213 to complete the refrigeration cycle.

[0043] On the coolant side, the hot water from the water-cooled condenser 214 flows through the outlet pipe of the water-cooled condenser 214, passes through the low-temperature radiator 125 for heat dissipation, flows through the water-to-water heat exchanger 212, and then returns to the water-cooled condenser 214 to complete the high-temperature side circulation; the water from the battery pack enters the cooler 216 for cooling after passing through the five-way water valve 21 in mode one, and is driven by the battery water pump 22 to enter the battery pack for cooling. At this time, the high-pressure heater 23 does not work, and the battery coolant and the water-cooled condenser coolant do not exchange heat.

[0044] In terms of control logic: On the refrigerant side, compressor 213 is controlled based on the water temperature detected by battery inlet water temperature sensor 24, with a target water temperature of 25℃ and a water temperature range of [10℃, 30℃]; expansion valve 217 is controlled in a closed loop based on the superheat at the outlet of cooler 216, with a superheat target of 10-15℃. On the coolant side, cooling fan 126 and radiator 125 water pumps are controlled by looking up the maximum value from a table based on the pressure detected by the high-pressure PT sensor 218 of each unit's refrigerant system. The higher the system high pressure, the larger the duty cycle of fan 126 and water pumps; the five-way valve is in mode one; battery water pump 22 operates with a fixed duty cycle to meet the water flow requirements of the battery pack.

[0045] Working Mode Two, such as Figure 4 As shown, when the ambient temperature is below 5°C and the battery pack requires cooling, the system enters the battery low-temperature cooling mode.

[0046] On the refrigerant side, compressor 213 and expansion valve 217 do not start, in order to reduce the unit's operating energy consumption, reduce the life cycle operating time of compressor 213, and avoid the risk of high failure rate of compressor 213 at low temperatures.

[0047] On the coolant side, the water outlet from the low-temperature side of the water-to-water heat exchanger 212 passes through the water outlet pipe of the water-cooled condenser and then through the low-temperature radiator 125 for heat dissipation before returning to the water-to-water heat exchanger 212. The water-to-water heat exchanger 212 indirectly exchanges heat with the battery cooler 216, dissipating the battery's heat through the radiator 125. The water-to-water heat exchanger 212 avoids direct interaction between the radiator's coolant and the battery coolant, preventing impurities on the radiator's coolant side from entering the battery pack and causing blockage of the battery pack's coolant side flow channel. The water outlet from the battery pack enters the high-temperature side of the water-cooled condenser 214 after passing through the five-way water valve 21 in mode two, where it indirectly exchanges heat with the coolant side of the water-cooled condenser to become low-temperature water. This water is then driven by the battery water pump 22 to enter the battery pack for cooling. At this time, the high-pressure heater 23 is still not working.

[0048] In terms of control logic, the cooling fan 126 and the radiator water pump are controlled by looking up the table based on the water temperature detected by the battery inlet water temperature sensor 24. The higher the battery inlet water temperature, the larger the duty cycle of the fan 126 and the water pump. The five-way valve is in mode two. The battery water pump 22 operates with a fixed duty cycle to meet the water flow requirements of the battery pack.

[0049] Work Mode 3, such as Figure 5 As shown, when the battery requires heating, the system enters the battery heating mode.

[0050] On the refrigerant side, compressor 213 does not start, and expansion valve 217 does not start.

[0051] On the coolant side, the water-cooled condenser coolant does not require driving; the water from the battery pack exits through the five-way water valve 21 in mode three, part of which is heated by the high-pressure heater 23, and the other part is heated by the cooler 216. The two parts of coolant are mixed and then driven by the battery water pump 22 to enter the battery pack to heat the battery pack. The diversion is to avoid the large flow of coolant through the high-pressure heater 23, which would cause excessive flow resistance and excessive flow velocity to erode the internal flow channel of the high-pressure heater 23.

[0052] In terms of control logic, on the coolant side, the cooling fan 126 and radiator water pump 127 are not started; the five-way valve is in mode three, with a 50%:50% flow split; the battery water pump 22 operates with a fixed duty cycle to meet the battery pack water flow requirements; the high-pressure heater 23 is controlled according to the water temperature detected by the battery inlet water temperature sensor 24, with a target temperature of 50℃.

[0053] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A battery thermal management system for electric mining trucks, characterized in that, This includes multiple parallel-connected general-purpose thermal management units and a shared vehicle-end radiator; Each of the general thermal management units includes a battery coolant side, a water-cooled condenser coolant side, and a refrigerant side; The battery coolant side includes a battery water pump, a five-way water valve, a cooler, and a high-pressure heater connected in a pipeline between the battery pack inlet and outlet, as well as a water temperature sensor for detecting the temperature of the inlet and outlet water of the battery; the five-way water valve has five interfaces A, B, C, D, and E, which are used to adjust the coolant flow direction by switching the interface connection status; The coolant side of the water-cooled condenser includes a water-cooled condenser, and the inlet and outlet of the water-cooled condenser are respectively connected to the outlet and inlet of the vehicle-end radiator. The refrigerant side includes a compressor, a water-cooled condenser, a liquid receiver-drier, an expansion valve, and a cooler connected in sequence by pipelines to form a refrigeration cycle loop; It also includes a water-to-water heat exchanger, through which the water passage on the battery coolant side and the water passage on the coolant side of the water-cooled condenser exchange heat indirectly. The water outlets of the water-cooled condensers of each of the general thermal management units converge and are connected to the inlet of the vehicle-end radiator via a radiator water pump. The water outlets of the vehicle-end radiators are then split and connected to the inlets of each of the water-cooled condensers.

2. The electric mining truck battery thermal management system according to claim 1, characterized in that, The five-way water valve has at least three operating modes: Mode 1: AD connected, CB connected, E closed; Mode 2: CD is connected, AB is connected, and E is closed. Mode 3: CB connected, CE connected, A closed, D closed.

3. The electric mining truck battery thermal management system according to claim 1, characterized in that, The battery coolant side is also connected to an exhaust and replenishment assembly, including a replenishment port connected to the battery water pump inlet and an exhaust port connected to the highest point of the cooling circuit. Each of the general thermal management units is equipped with an independent expansion tank, and the vehicle-end radiator is matched with an independent expansion tank.

4. The electric mining truck battery thermal management system according to claim 1, characterized in that, The refrigerant side is also equipped with a high-pressure PT sensor and a low-pressure PT sensor. The high-pressure PT sensor is installed in the pipeline between the compressor exhaust port and the water-cooled condenser, and the low-pressure PT sensor is installed in the pipeline between the cooler outlet and the compressor.

5. The electric mining truck battery thermal management system according to claim 1, characterized in that, The compressor is a general-purpose electric scroll compressor that uses R134a or R1234yf refrigerant. Both the water-cooled condenser and the cooler are plate heat exchangers. The expansion valve is a thermostatic expansion valve, an electronic expansion valve, or an electromagnetic expansion valve.

6. A control method based on the electric mining truck battery thermal management system according to any one of claims 1 to 5, characterized in that, Includes the following steps: When the ambient temperature is higher than 5°C and the battery pack requires cooling, the control unit enters the high-temperature cooling mode. When the ambient temperature is below 5°C and the battery pack requires cooling, the control unit enters the low-temperature cooling mode. When the battery pack requires heating, the control unit enters the heating mode.

7. The control method for the electric mining truck battery thermal management system according to claim 6, characterized in that, In the high-temperature cooling mode: Set the five-way water valve to mode one, start the compressor, and turn off the high-pressure heater; The compressor frequency is adjusted based on the battery inlet water temperature, which is set at 25℃ and controlled within the range of 10℃-30℃. The expansion valve is controlled to perform closed-loop regulation based on the superheat at the cooler outlet, with the target superheat set at 10-15℃. The duty cycle of the radiator fan and radiator water pump is adjusted by referring to a table based on the maximum value of the high-pressure PT sensor of each unit. The higher the pressure, the larger the duty cycle. Control the battery water pump to operate at a fixed duty cycle to meet flow requirements.

8. The control method for the battery thermal management system of the electric mining truck according to claim 6, characterized in that, In the low-temperature refrigeration mode: Set the five-way water valve to mode two to shut down the compressor and high-pressure heater. The battery coolant is controlled to exchange heat indirectly with the coolant side of the water-cooled condenser through a water-to-water heat exchanger, and passive heat dissipation is achieved using the vehicle-end radiator. The duty cycle of the radiator fan and radiator water pump is adjusted by referring to a table based on the battery inlet water temperature; the higher the temperature, the larger the duty cycle. Control the battery water pump to operate at a fixed duty cycle to meet flow requirements.

9. The control method for the battery thermal management system of the electric mining truck according to claim 6, characterized in that, In the heating mode: Set the five-way water valve to mode three, turn off the compressor and refrigerant side, and turn off the radiator fan and radiator water pump; The water outlet of the battery is controlled to be split through a five-way water valve. Part of the water flows through a high-pressure heater for heating, and the other part flows through a bypass pipeline. The two streams are mixed and then sent back to the battery pack by the battery water pump. The heating power of the high-pressure heater is adjusted to target the battery inlet water temperature, which is set at 50°C. Control the battery water pump to operate at a fixed duty cycle to meet flow requirements.

10. The control method for the battery thermal management system of the electric mining truck according to claim 6, characterized in that, In mode three, the flow area ratio of the five-way water valve from port C to port B to port C to port E is controlled at 50%:50%. Furthermore, the battery thermal management unit system is configured with a corresponding number of general thermal management units according to the number of battery packs. Each unit independently controls its corresponding battery pack, and the water-cooled condenser side of each unit is connected in parallel to the shared vehicle-end radiator circuit.

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