Immersed battery thermal management system

Abstract

The utility model discloses an immersed battery thermal management system which comprises a battery arranged in a battery box, phase change immersion liquid is contained in the battery box, the battery box is connected with a circulating system for circulating the phase change immersion liquid, and an inlet and an outlet of a circulating pump of the circulating system are respectively connected with the battery box through pipelines; the system further comprises a refrigerant cooling system, the refrigerant cooling system comprises a fin type heat exchanger arranged above the battery, a refrigerant inlet of the fin type heat exchanger is connected with an outlet of a gas-liquid separator loaded with refrigerant through a condenser, and an inlet of the gas-liquid separator is connected with a refrigerant outlet of the fin type heat exchanger through a heat exchanger. The phase change immersion liquid circulation system and the refrigerant cooling system are combined, the severe change of the thermal load of the forklift battery is effectively dealt with, the temperature rise rate of the battery is controlled, and the temperature of the battery is prevented from being too high, so that thermal runaway is prevented, the service life of the battery is prolonged, and the rapid response of the thermal management system to the thermal load change is realized.

Description

Technical Field

[0001] The utility model relates to the field of thermal management of vehicle-mounted power batteries, and particularly to an immersion battery thermal management system for electric forklifts. Background Art

[0002] New energy vehicles have developed rapidly, and electric forklifts are increasingly used in the forklift field. The energy core of electric forklifts is the battery. To improve the battery safety and service life, it is necessary to control the battery temperature, that is, when the battery temperature is low, the battery needs to be heated; when the battery temperature is high, the battery needs to be cooled down.

[0003] At present, most of the battery thermal management systems of electric forklifts are the same as those of electric vehicles, adopting an indirect liquid cooling method, where the coolant flows in the cold plate to indirectly take away the heat of the battery in contact with the cold plate. However, there are significant differences between forklifts and cars in their own characteristics and operating conditions. Forklifts are heavy and need to lift heavy objects, and there are frequent lifting, lowering, and driving action transitions during operation, while cars are light and the operating conditions are relatively stable. Therefore, the battery load of forklifts is greater and changes more violently, so its battery heat load is higher and the fluctuation is more significant.

[0004] Moreover, the indirect liquid cooling method has a small heat transfer coefficient and a slow response to battery temperature changes, which will cause heat accumulation in the forklift battery, rapid temperature rise and larger temperature difference, and is not conducive to the battery use safety and service life. At the same time, when the heat dissipation capacity of the battery management system (BMS) is insufficient to ensure the battery use safety and prevent battery thermal runaway, it will limit the battery charge and discharge power, thus reducing the battery power performance and fast charging performance of the forklift. Therefore, the indirect liquid cooling method is not suitable for electric forklifts.

[0005] The direct liquid cooling method is also called immersion cooling, which means using an insulating immersion liquid to directly exchange heat with the battery. Compared with the indirect liquid cooling method, it reduces the heat transfer resistance, increases the heat transfer coefficient, and enlarges the heat transfer area, with better temperature uniformity. However, due to the large amount of immersion liquid used, the full immersion cooling method has a large additional weight and high cost, which limits its application in the field of automotive power battery thermal management.

[0006] Compared with the indirect liquid cooling method, the immersion cooling method has the advantages of enhanced heat transfer and high battery temperature uniformity, and can better cope with the characteristics of high heat load and large fluctuation of the electric forklift battery, thus ensuring the battery use safety and improving the battery charge and discharge performance. In addition, due to the weight requirement of the forklift, the problem of additional weight brought by the immersion liquid can be ignored in the forklift. Summary of the Utility Model

[0007] In order to solve the above existing problems, the utility model provides a battery thermal management system with low cost and strong practicability for electric forklifts.

[0008] The technical solution of the present utility model is as follows:

[0009] An immersion battery thermal management system includes a battery disposed inside a battery box. The battery box is a sealed box structure, and a phase change immersion liquid is contained therein. The battery box is connected to a circulation system for circulating the phase change immersion liquid. The circulation system includes a circulation pump, and the inlet and outlet of the circulation pump are respectively connected to the battery box through pipelines.

[0010] It further includes a refrigerant cooling system. The refrigerant cooling system includes a fin heat exchanger disposed above the battery. The refrigerant inlet of the fin heat exchanger is connected to the outlet of a gas-liquid separator loaded with refrigerant through a condenser, and the inlet of the gas-liquid separator is connected to the refrigerant outlet of the fin heat exchanger through a heat exchanger.

[0011] In a further solution, the outlet end of the circulation pump is connected to a three-way reversing valve to divide the immersion liquid into two paths: a heat dissipation pipeline and a bypass pipeline. Both the heat dissipation pipeline and the bypass pipeline are communicated with the battery box through a return pipeline. A radiator and a heat exchanger are sequentially connected on the heat dissipation pipeline.

[0012] In a preferred solution, the circulation system further includes a sprinkler disposed directly above the battery. A plurality of nozzles are provided on the sprinkler, and the liquid inlet of the sprinkler is communicated with the heat dissipation pipeline and the bypass pipeline respectively through a sprinkler pipeline.

[0013] In a more preferred solution, a pressure sensor is installed on the sprinkler pipeline, a flow regulating valve is installed on the return pipeline, and a temperature sensor is installed on the pipeline connecting the immersion liquid outlet of the battery box and the circulation pump.

[0014] In a further solution, a heating device is provided inside the battery box. The heating device includes a PTC heater disposed at the bottom end inside the battery box and a thin film heating sheet disposed on the side wall of the battery. A pressure relief valve is installed on the top surface of the battery box.

[0015] In a further solution, a compressor is installed between the condenser and the gas-liquid separator, and a throttle valve is installed between the condenser and the fin heat exchanger.

[0016] In this application, a phase change immersion liquid is selected for semi-immersion liquid cooling. The phase change immersion liquid refers to a volatile immersion liquid, that is, it has a low boiling point. When the ambient heat reaches a certain condition, it will absorb heat using latent heat and generate a boiling phase change, thereby cooling the equipment. The immersion liquid vapor is then condensed by a condenser into a liquid state for cyclic heat exchange.

[0017] The beneficial effects of the present utility model are as follows:

[0018] 1. This application builds a thermal management system for electric forklift batteries based on the immersion cooling method. By directly exchanging heat between the immersion liquid and the battery, the heat transfer coefficient and area are increased, thereby improving the heat dissipation performance to meet the thermal management requirements of forklift batteries.

[0019] 2. This application uses a combination of semi-immersion and spray cooling to manage the battery's heat, that is, the lower part of the battery is immersed in the immersion liquid and the top is sprayed with the immersion liquid to achieve direct and uniform cooling of the battery. It not only retains the good temperature uniformity of full-immersion cooling but also reduces the amount of immersion liquid used and lowers the application cost.

[0020] 3. This application utilizes the latent heat of phase change of the immersion liquid to effectively handle the drastic changes in the heat load of forklift batteries, control the battery temperature rise rate, prevent the battery from overheating, thus preventing thermal runaway and extending the battery life; in case of thermal runaway, the immersion liquid rapidly undergoes phase change and absorbs heat to inhibit the spread of thermal runaway, and a pressure relief valve is set to prevent explosion risks.

[0021] 4. This application couples a refrigerant cooling system to quickly condense the vapor generated by the phase change of the immersion liquid; utilizes the characteristic of the refrigerant cooling system to quickly adjust the cooling capacity to achieve a rapid response of the thermal management system to heat load changes; and has multiple operating modes to meet the thermal management requirements under various working conditions. Description of the Drawings

[0022] Figure 1 It is a schematic diagram of the battery thermal management system of the present utility model.

[0023] In the figure: 1 - battery box, 11 - battery, 12 - pressure relief valve, 13 - immersion liquid outlet, 14 - immersion liquid inlet;

[0024] 2 - fin heat exchanger, 21 - refrigerant inlet, 22 - refrigerant outlet;

[0025] 3 - sprayer, 31 - spray pipe inlet, 32 - nozzle;

[0026] 4 - PTC heater, 5 - heat exchanger, 6 - radiator, 7 - circulation pump, 8 - gas-liquid separator, 9 - compressor, 10 - condenser, 110 - pressure sensor;

[0027] 110 - pressure sensor, 111 - flow regulating valve, 112 - three-way reversing valve, 113 - temperature sensor, 114 - throttle valve;

[0028] L1 - heat dissipation pipeline, L2 - bypass pipeline, L3 - return pipeline, L4 - spray pipeline. Detailed Embodiment

[0029] The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Apparently, the described embodiments are only a part of the embodiments of the present utility model, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0030] Referring to Figure 1 , an immersion battery thermal management system includes a battery 11 disposed inside a battery box 1. The battery box 1 is a sealed box structure, and a phase change immersion liquid is contained therein. The battery box 1 is connected to a circulation system for circulating the phase change immersion liquid. The circulation system includes a circulation pump 7, and the inlet and outlet of the circulation pump 7 are respectively connected to the battery box 1 through pipelines.

[0031] It further includes a refrigerant cooling system. The refrigerant cooling system includes a fin heat exchanger 2 disposed above the battery 11. The refrigerant inlet 21 of the fin heat exchanger 2 is connected to the outlet of a gas-liquid separator 8 loaded with refrigerant through a condenser 10, and the inlet of the gas-liquid separator 8 is connected to the refrigerant outlet 22 of the fin heat exchanger 2 through a heat exchanger 5.

[0032] In this embodiment, a circulation system is combined with a refrigerant cooling system. The circulation system is used to drive the phase change immersion liquid to circulate inside and outside the battery box 1 and spray to the top of the battery 11. Combining the functions of a radiator 6, a PTC heater 4, and a film heating sheet, uniform cooling and heating of the battery are realized. The refrigerant cooling system is used to quickly condense the steam generated by the phase change of the immersion liquid during the operation of the circulation system, and utilize its characteristic of quickly adjusting the cooling capacity to achieve a quick response of the thermal management system to changes in the heat load. With the circulation system as the main body and the refrigerant cooling system as the auxiliary, thermal management of the battery for cooling under high-temperature conditions or heating under low-temperature conditions is realized.

[0033] To adapt to various modes of thermal management, the outlet end of the circulation pump 7 is connected to a three-way reversing valve 112 to divide the immersion liquid into two paths: a heat dissipation pipeline L1 and a bypass pipeline L2. Both the heat dissipation pipeline L1 and the bypass pipeline L2 are connected to the battery box 1 through a return pipeline L3. A radiator 6 and a heat exchanger 5 are sequentially connected on the heat dissipation pipeline L1.

[0034] In this application, the three-way reversing valve is preferably a three-way electromagnetic reversing valve. As Figure 1 shown, it has three valve ports A, B, and C. The three-way reversing valve can be controlled by an electrical signal to make the first valve port A communicate with the second valve port B and not communicate with the third valve port C, or the first valve port A communicate with the third valve port C and not communicate with the second valve port B.

[0035] By controlling the on-off of the three valve ports A, B, and C in the three-way reversing valve 112, the circulation path of the immersion liquid is controlled, that is, whether the immersion liquid enters the heat dissipation pipeline L1, passes through the radiator 6 and the heat exchanger 5, and exchanges heat with the external environment and the refrigerant respectively, or enters the bypass pipeline L2 to bypass the radiator 6 and the heat exchanger 5 without exchanging heat with the external environment and the refrigerant.

[0036] In order to cool the battery directly and evenly, the circulation system further includes a sprayer 3 arranged directly above the battery 11, and a plurality of nozzles 32 are provided on the sprayer 3. The liquid inlet 31 of the sprayer 3 is respectively connected with the heat dissipation pipeline L1 and the bypass pipeline L2 through the spray pipeline L4. That is, the lower part of the battery is immersed in the immersion liquid, and the immersion liquid is sprayed on the top, so that the battery is directly and evenly cooled, which not only retains the good temperature uniformity of the fully immersed cooling battery, but also reduces the amount of immersion liquid used and reduces the application cost.

[0037] In order to better and efficiently control the thermal management system, a pressure sensor 110 is installed on the spray pipe L4, a flow regulating valve 111 is installed on the return pipe L3, and a temperature sensor 113 is installed on the pipeline connecting the immersion liquid outlet 13 on the battery box 1 and the circulation pump 7.

[0038] In order to manage the battery at low temperatures, a heating device is provided inside the battery box 1, and the heating device includes a PTC heater 4 provided at the bottom end of the battery box 1 and a thin film heating plate provided on the side wall of the battery 11; a pressure relief valve 12 is installed on the top surface of the battery box 1. In this application, the PTC heater 4 and the thin film electric heating plate are used for heating in winter. Both are products well known in the art, and are sealed with an insulating shell on the outside and can be used in liquids. The purpose of setting a pressure relief valve is to prevent the phase change immersion fluid from absorbing heat and evaporating in large quantities when the battery is under thermal runaway, causing the air pressure in the box to rise rapidly and create an explosion risk. After setting a suitable pressure relief valve, when the gas pressure in the box reaches the pressure threshold of the pressure relief valve, the gas will be discharged from the pressure relief valve 12, thereby improving safety.

[0039] In a further solution, a compressor 9 is installed between the condenser 10 and the gas-liquid separator 8 , and a throttle valve 114 is installed between the condenser 10 and the fin heat exchanger 2 .

[0040] The phase change immersion liquid in this application is selected from electronic fluoride liquid commonly used in the art, and the electronic fluoride liquid can be a mixture of one or more of Novec 649, Novec 7000, Novec 7100, SF33 and HFE-6512. The amount of immersion liquid used in this application is about half of the height of the battery (such as Figure 1As shown by the dashed line in the figure, it is semi-immersed, and the total amount of immersion liquid can be reduced compared to the fully immersed type. The amount of immersion liquid is selected according to the lowest liquid level requirement during the operation of the thermal management system.

[0041] In this embodiment, the radiator 6 is used for heat exchange between the immersion liquid and the external environment, the heat exchanger 5 is used for heat exchange between the refrigerant and the immersion liquid, the condenser 10 is used for heat exchange between the refrigerant and the external environment in the refrigerant cooling system, and the start and stop of the compressor 9 control the working or non-working state of the refrigerant refrigeration system. The fin heat exchanger 2 is used to condense the steam generated by the phase change of the immersion liquid, and the sprayer 3 is used to evenly spray the immersion liquid onto the top of the battery for cooling or heating.

[0042] The thermal management system of the present application further includes a controller. The output ends of the temperature sensor 113, the pressure sensor 110, and the battery BMS (not shown in the figure, which is a well-known battery management system in the field of vehicle-mounted batteries, used to collect the voltage, current, and temperature of battery cells, and control the charging and discharging behavior of the battery pack, etc.), the thermometer outside the box, and the pressure sensor inside the box are all connected to the controller. The output end of the controller is respectively connected to the circulation pump 7, the compressor 9, the flow regulating valve 111, and the three-way reversing valve 112. The controller controls the rotation speed of the circulation pump 7 according to the temperature signal collected by the temperature sensor 113; the controller controls the opening, closing, and opening degree of the flow regulating valve 111 according to the pressure on the spray pipeline L4 collected by the pressure sensor 110; the controller controls the start and stop of the compressor 9 according to the pressure inside the battery box; the controller makes a decision and executes the flow path of the immersion liquid in the circulation system by controlling the valve port passage of the three-way reversing valve 112 according to the average temperature of the battery collected by the battery BMS, the ambient temperature collected by the thermometer outside the box, and the temperature of the immersion liquid at the outlet collected by the temperature sensor 113. The controller in the present application can use a commercially available controller, and a model that can collect signals, process, and control relevant setting switches can be selected according to the actual situation.

[0043] In the present application, the rotation speed of the circulation pump 7 is proportionally adjusted based on the temperature of the immersion liquid collected by the temperature sensor 113 at the outlet 13 of the immersion liquid. When the collected temperature of the immersion liquid is greater than (T0 + T1) / 2, the rotation speed of the circulation pump starts to increase, causing the flow rate to increase. When the temperature of the immersion liquid reaches T1, the rotation speed of the circulation pump reaches the maximum, increasing the heat dissipation power of the radiator to adapt to the change in the battery heat load.

[0044] Due to the relatively large flow resistance of the immersion liquid at the nozzle 32 of the sprayer 3, in order to cope with the influence of the increase in the rotational speed of the circulation pump on the pressure of the spray pipeline L4, a pressure sensor 110 is provided on the spray pipeline L4 to detect its hydraulic pressure, and the opening, closing, and opening degree of the flow regulating valve 111 are controlled. By adjusting its opening degree, the flow rate of the immersion liquid in the return pipeline L3 is changed. When the pressure of the spray pipeline L4 is too high, the flow regulating valve 111 is opened so that part of the immersion liquid directly returns to the bottom of the battery box through the return pipeline L3, thereby controlling the pressure of the spray pipeline L4, ensuring that the spray effect meets the expectations, and realizing overpressure prevention of the spray pipeline L4.

[0045] In this application, the immersion battery thermal management system has multiple working modes, which can meet different thermal management requirements. Specifically, there are:

[0046] I. High-temperature cooling mode

[0047] In this mode, due to the high external environmental temperature and high thermal load of the forklift battery, the temperature of the immersion liquid reaches the boiling point of the immersion liquid, so the immersion liquid evaporates more, and the gas pressure in the battery box is at a relatively high value. Both the refrigerant cooling system and the circulation system need to be turned on.

[0048] The working process of the refrigerant cooling system is as follows: The compressor 9 starts, and the working medium (refrigerant) flow path of the refrigerant cooling system is: The low-pressure refrigerant vapor in the gas-liquid separator 8 is sucked into the compressor 9, compressed into high-pressure vapor and enters the condenser 10 to release heat and condense into medium-temperature and high-pressure liquid. After throttling and pressure reduction by the throttle valve 114, it becomes low-temperature and low-pressure liquid, and then enters the fin heat exchanger 2 from the refrigerant inlet 21, absorbs heat and evaporates from the external immersion liquid vapor, thereby condensing the immersion liquid vapor to maintain the pressure in the battery box within the normal working range. After coming out from the refrigerant outlet 22, it enters the heat exchanger 5, exchanges heat with the high-temperature immersion liquid therein and absorbs heat and evaporates, further cooling the immersion liquid, and finally returns to the gas-liquid separator 8 to form a heat exchange cycle.

[0049] The working process of the circulation system is as follows: The circulation pump 7 is turned on, the flow regulating valve 111 is turned on, and the first valve port A and the second valve port B of the three-way reversing valve 112 are controlled to communicate, so that the working medium (immersion liquid) flow path in the circulation system is: The immersion liquid flows out through the immersion liquid outlet 13, is pumped into the first valve port A of the three-way reversing valve 112 by the circulation pump 7, and enters the heat dissipation pipeline L1 through the second valve port B, dissipates heat to the outside through the radiator 6, and then enters the heat exchanger 5 for further cooling. Part of the cooled immersion liquid returns to the bottom of the battery box 1 through the return pipeline L3 from the immersion liquid inlet 14, and the other part enters the sprayer 3 through the spray pipeline L4, is evenly sprayed onto the top of the battery 11 through the nozzle 32 to cool the top of the battery, and finally returns to the bottom of the battery box through the battery gap or the perforated heat insulation material.

[0050] This mode utilizes a circulation system to perform immersion cooling on the bottom of the battery and spray cooling on the top, thus achieving comprehensive cooling and improving the battery temperature uniformity; it utilizes the latent heat of liquid-phase change of the immersion liquid to cope with the drastic change of the battery heat load and control the temperature rise rate; it utilizes the refrigerant cooling system to quickly condense the vapor of the immersion liquid, so as to quickly respond to the change of the battery heat load and maintain the pressure inside the box within the normal working range.

[0051] II. Low-temperature cooling mode

[0052] In this mode, although the forklift battery has a high heat load and still needs to be cooled, due to the low external ambient temperature and the high cooling efficiency of the circulation system, it can be cooled only through the circulation system, and the temperature of the immersion liquid is controlled below its boiling point, so that the gas pressure inside the battery box is within the normal working range. That is, in this mode, the circulation system is used for cooling, while the refrigerant cooling system does not work.

[0053] Cycle 1: The circulation pump 7 is turned on, the flow regulating valve 111 is opened to the maximum opening, and the first valve port A of the three-way reversing valve 112 is controlled to communicate with the second valve port B, so that the flow path of the working medium of the circulation system is: the immersion liquid flows out through the immersion liquid outlet 13, is pumped into the first valve port A of the three-way reversing valve 112 by the circulation pump 7, enters the heat dissipation pipeline L1 through the second valve port B, dissipates heat to the outside through the radiator 6, and then directly returns to the bottom of the battery box through the heat exchanger 5 and the return pipeline L3.

[0054] Cycle 2: The circulation pump 7 is turned on, the flow regulating valve 111 is closed, the PTC heater 4 and the thin-film electric heating sheet are both turned off, and the first valve port A of the three-way reversing valve 112 is controlled to communicate with the third valve port C, so that the working medium of the circulation system flows as follows: the immersion liquid flows out through the immersion liquid outlet 13, is pumped into the three-way reversing valve 112 by the circulation pump 7 and then enters the bypass pipeline L2, and finally enters the spray pipeline L4, and is evenly sprayed onto the top of the battery 11 through the sprayer 3. The immersion liquid after cooling the battery flows back to the bottom of the battery box through the battery gap or the porous heat insulation material.

[0055] In this mode, after quickly cooling the immersion liquid to a suitable temperature by using Cycle 1, the immersion liquid at the suitable temperature is then sprayed onto the top of the battery by using Cycle 2. Cycle 1 and Cycle 2 run alternately to achieve uniform cooling of the battery, preventing the problem of temperature non-uniformity caused by directly spraying the immersion liquid, which has been cooled too low by the radiator, onto the top of the battery.

[0056] III. Low-temperature heating mode

[0057] In this mode, since the battery temperature is too low to start normally, the PTC heater 4 and the thin-film electric heating sheet are turned on to heat the immersion liquid and the battery, and the circulation system is also operated.

[0058] The circulation pump 7 is turned on, the flow regulating valve 111 is turned on, the PTC heater 4 and the thin-film electric heating sheet 15 operate, and the first valve port A of the three-way reversing valve 112 is made to communicate with the third valve port C, so that the working fluid flow path of the circulation system is as follows: After the immersion liquid is heated, it flows out from the immersion liquid outlet 13, is pumped into the three-way reversing valve 112 by the circulation pump 7 and then enters the bypass pipeline L2. Then, a part of it directly returns to the bottom of the battery box through the return pipeline L3, and another part enters the sprayer 3 through the spray pipeline L4, is evenly sprayed onto the top of the battery 11, and after heating the battery, it flows back to the bottom through the battery gap or the porous heat-insulating material.

[0059] This mode uses the PTC heater 4 and the thin-film electric heating sheet to quickly heat the immersion liquid and the battery 11, and uses the circulation system to ensure that the immersion liquid and the battery 11 are evenly heated.

[0060] Although this specification is described according to the embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0061] Therefore, the above description is only the preferred embodiment of the present application, and is not used to limit the scope of implementation of the present application; that is, all equivalent transformations made according to the scope of the claims of the present application are within the protection scope of the claims of the present application.

Claims

1. An immersion battery thermal management system, comprising a battery (11) arranged inside a battery box (1), wherein the battery box (1) is a sealed box structure, and a phase change immersion liquid is contained inside the battery box, characterized in that: The battery box (1) is connected to a circulation system for circulating the phase-change immersion liquid, the circulation system comprising a circulation pump (7), the inlet and outlet of the circulation pump (7) being respectively connected to the battery box (1) via pipelines; It also includes a refrigerant cooling system, which includes a fin heat exchanger (2) arranged above the battery (11), the refrigerant inlet (21) of the fin heat exchanger (2) is connected to the outlet of a gas-liquid separator (8) loaded with refrigerant through a condenser (10), and the inlet of the gas-liquid separator (8) is connected to the refrigerant outlet (22) of the fin heat exchanger (2) through a heat exchanger (5).

2. The submerged battery thermal management system according to claim 1, characterized in that: The outlet end of the circulation pump (7) is connected to a three-way reversing valve (112) to divide the immersion liquid into two paths: a heat dissipation pipeline (L1) and a bypass pipeline (L2); the heat dissipation pipeline (L1) and the bypass pipeline (L2) are both connected to the battery box (1) through a return pipe (L3); and the heat dissipation pipeline (L1) is connected in sequence to a radiator (6) and a heat exchanger (5).

3. The submerged battery thermal management system according to claim 2, characterized in that: The circulation system further comprises a sprayer (3) arranged directly above the battery (11), the sprayer (3) being provided with a plurality of nozzles (32), and the liquid inlet (31) of the sprayer (3) being respectively connected to the heat dissipation pipeline (L1) and the bypass pipeline (L2) through a spray pipeline (L4).

4. The submerged battery thermal management system according to claim 3, characterized in that: The spray pipe (L4) is installed with a pressure sensor (110), the return pipe (L3) is installed with a flow regulating valve (111), and the pipeline connecting the immersion liquid outlet (13) on the battery box (1) and the circulation pump (7) is installed with a temperature sensor (113).

5. The submerged battery thermal management system according to claim 1, characterized in that: A heating device is provided inside the battery box (1), the heating device comprising a PTC heater (4) provided at the bottom end of the battery box (1) and a thin film heating plate provided on the side wall of the battery (11); a pressure relief valve (12) is installed on the top surface of the battery box (1).

6. The submerged battery thermal management system according to claim 1, characterized in that: A compressor (9) is installed between the condenser (10) and the gas-liquid separator (8), and a throttle valve (114) is installed between the condenser (10) and the fin heat exchanger (2).

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