Liquid cooling and heating control method and control system for efficient battery energy storage

Abstract

The invention relates to the technical field of battery energy storage, in particular to a high-efficiency liquid cooling and heating control method and system for battery energy storage, and the control method comprises the steps: collecting parameters which comprise environment temperature, working current and battery cell temperature; the collected parameters are compared with corresponding threshold values, and the grade of each parameter is judged; multiplying the grade of each parameter by the corresponding weight and then adding to obtain a comprehensive cooling grade; and implementing a corresponding cooling grade strategy according to the comprehensive cooling grade. Through the control method and the control system, the problems of battery thermal management and liquid cooling unit energy conservation of an existing battery energy storage system can be solved, the energy consumption of the liquid cooling unit can be reduced, and the battery temperature and the temperature difference between the batteries are controlled within a reasonable range.

Description

Technical Field

[0001] The present invention relates to the technical field of battery energy storage, and in particular to a liquid cooling and heating control method and a control system for efficient battery energy storage. Background Art

[0002] The energy storage battery is one of the core components of the energy storage system. When the energy storage battery operates in a high temperature environment, it will affect the performance and service life of the energy storage battery. The ambient temperature of the energy storage battery and the power output and input inside the battery will affect the temperature of the battery. Therefore, in order to ensure the eligibility of the operating temperature of the energy storage battery, the ambient temperature and operating temperature of the energy storage battery need to be monitored and regulated.

[0003] In the prior art, a Chinese invention patent document with publication number CN118380682A and publication date July 23, 2024 is proposed. The technical solution disclosed in the patent document is as follows: a hybrid thermal management system and method for energy storage batteries, the system includes a battery box and a chiller integrated with a hybrid thermal management system, the battery box is installed with a battery module, a phase change material module, a microchannel liquid cooling plate and a spray cooling device; the microchannel liquid cooling plate includes a first microchannel liquid cooling plate and a second microchannel liquid cooling plate, which absorbs heat through the active flow of coolant liquid; the phase change material module is a composite phase change material uniformly filled between the battery module and the microchannel liquid cooling plate, which absorbs the heat of the battery pack in the form of sensible heat and latent heat; the spray cooling device is located above the battery pack and the composite phase change material, and can quickly absorb a large amount of heat emitted by the battery pack under extreme working conditions, suppress the risk of thermal runaway of the battery, and ensure the safe operation of the energy storage system.

[0004] The above technical solution may cause the following problems during actual use: (1) The system is complex and the manufacturing cost is high. The battery module in this technical solution includes microchannel liquid cooling, phase change materials, and a spray device. Compared with the traditional liquid-cooled battery module that only includes a liquid cooling plate, the battery module in this technical solution is larger in size, heavier in weight, and has a high manufacturing cost.

[0005] (2) This technical solution has insufficient reliability and potential safety hazards. The battery module in this technical solution is filled with paraffin-based phase change materials. This phase change material is more dependent on active cooling technology. Once the active cooling technology fails, its ability to sustainably absorb heat is greatly weakened, and it may even cause heat damage, resulting in heat accumulation and thermal safety hazards.

[0006] In the prior art, a Chinese invention patent document with publication number CN118336223A and publication date July 12, 2024 has also been proposed. The technical solution disclosed in the patent document is as follows: a high-efficiency energy storage battery liquid cooling unit, comprising: a current ambient temperature monitoring subsystem for monitoring the current ambient temperature; an intelligent refrigeration control model acquisition subsystem for acquiring an intelligent refrigeration control model, the control components of the intelligent refrigeration control model being: a target compressor and a fluorine pump; an intelligent refrigeration control subsystem for performing intelligent refrigeration control according to the current ambient temperature and the intelligent refrigeration control model.

[0007] The above technical solution may cause the following problems during actual use: (1) This technical solution adds a fluorine pump component to the hardware, which increases the initial investment cost. In addition, the fluorine pump operation control accuracy requirements are high, and the subsequent operation and maintenance costs are high.

[0008] (2) The control strategy of this technical solution is single, which is a simple on-off control strategy, and the input parameter is only the ambient temperature. The energy-saving effect of this control strategy is limited. Summary of the invention

[0009] In order to solve the above technical problems, the present invention proposes a liquid cooling thermal control method and control system for efficient battery energy storage, which can solve the problems of battery thermal management and liquid cooling unit energy saving in existing battery energy storage systems, reduce the energy consumption of the liquid cooling unit, and control the battery temperature and the temperature difference between batteries within a reasonable range.

[0010] The present invention is achieved by adopting the following technical solutions: A method for controlling liquid cooling and heating for efficient battery energy storage comprises the following steps: Step S 1 . Collecting parameters, including ambient temperature, operating current and battery cell temperature; Step S 2 . Compare the collected parameters with the corresponding thresholds to determine the level of each parameter; Step S 3 . Multiply the level of each parameter by the corresponding weight and then add them together to get the comprehensive cooling level; Step S 4 . Implement corresponding cooling level strategy according to the comprehensive cooling level.

[0011] When the cell temperature is less than or equal to the corresponding temperature threshold, the heating strategy is turned on.

[0012] The parameters are collected once every preset time period.

[0013] The comprehensive cooling levels include level 1, level 2 and level 3, and the cooling level strategies include level 1 cooling strategy, level 2 cooling strategy and level 3 cooling strategy; when the comprehensive cooling level is level 1, the level 1 cooling strategy is executed; when the comprehensive cooling level is not level 1, the maximum temperature of the battery cell is compared with the preset value. If it is less than or equal to the preset value, the level 2 cooling strategy is executed; if it is greater than the preset value, the level 3 cooling strategy is executed.

[0014] A liquid cooling and heat control system for efficient battery energy storage comprises a liquid cooling unit subsystem and a battery subsystem, wherein the liquid cooling unit subsystem comprises a compressor, a condenser, a plate heat exchanger, a throttling element, a natural air cooling radiator and an electromagnetic three-way valve; the battery subsystem comprises a battery pack, a cold plate is arranged in the battery pack, and a flow channel for the flow of coolant is arranged inside the cold plate; after the coolant in the cold plate of the battery pack exchanges heat with the battery pack, it passes through the electromagnetic three-way valve, exchanges heat with the outside low-temperature air through the natural air cooling radiator, and then returns to the cold plate, or / and, exchanges heat with the low-temperature and low-pressure liquid / saturated refrigerant coming out of the compressor and processed by the condenser and the throttling element through the plate heat exchanger, and then returns to the cold plate.

[0015] The battery subsystem further includes a battery management unit, which includes: A data acquisition module monitors various parameters in real time, including ambient temperature, battery cell temperature and operating current; The decision-making module compares the collected parameters with the corresponding thresholds, determines the level of each parameter, and multiplies the level of each parameter with the corresponding weight to obtain the comprehensive cooling level; The execution module controls the valve opening of the electromagnetic three-way valve and the speed of the compressor and / or the speed of the natural air cooling radiator according to the comprehensive cooling level, and implements the corresponding cooling level strategy.

[0016] A one-way valve is arranged between the electromagnetic three-way valve and the natural air cooling radiator.

[0017] A PTC heater is also included for heating the coolant.

[0018] Also includes expansion tank.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. In the control method of the present invention, by combining multi-parameter input and refrigeration mode step adjustment, the current extensive thermal management strategy that only relies on battery temperature input and switch control is replaced to achieve fine optimization of thermal management energy consumption, taking into account temperature control performance and unit energy consumption. Specifically, the present invention uses three parameters: ambient temperature, battery cell temperature, and operating current as inputs for decision-making and judgment, and judges the importance of each parameter in the control to achieve comprehensive management and control. The ambient temperature and battery cell temperature both directly reflect the current temperature value. The size of the operating current is a key factor affecting the heat generation of the battery. Using the operating current as a decision-making input parameter fully compensates for the hidden dangers brought about by thermal inertia. Thermal inertia, that is, the change in temperature, lags behind the heat generation process. Combined with the multi-stage gradient cooling strategy of the present invention, fine control of the battery temperature can be achieved.

[0020] 2. This control method can also realize heating control and achieve energy saving under all environmental conditions.

[0021] 3. In this control system, the refrigeration cycle includes two, compression refrigeration cycle and natural heat dissipation cycle. The energy consumed by natural heat dissipation is only about 20% of that of compression refrigeration. In a relatively low temperature environment, compared with the existing liquid cooling unit that relies solely on compression refrigeration cycle, by adding a natural air cooling radiator and a corresponding coolant circuit, the high-temperature coolant from the cold plate of the battery pack flows through the natural air cooling radiator and is cooled, thereby reducing the load on the refrigeration side of the compressor and reducing energy consumption, which greatly improves the energy efficiency ratio of the unit.

[0022] Furthermore, compared with the solution in the prior art of achieving heat dissipation by adding a water spray device, the present invention can also solve the shortcomings of increased cost, more complex system, and insufficient reliability of the water spray device, and can reduce the energy consumption of the unit.

[0023] 4. This control system also includes a battery management unit, which can realize the combination of multi-parameter input, refrigeration mode step adjustment and multi-object control, realize the fine optimization of thermal management energy consumption, and take into account both temperature control performance and unit energy consumption. In the specific control process, the solenoid three-way valve can be used to distribute the coolant flow of the compression refrigeration cycle and the natural heat dissipation cycle, so as to better adapt to the regulation of different ambient temperatures.

[0024] 5. The setting of the one-way valve can prevent the coolant from flowing back and improve the stability of the entire control system.

[0025] 6. The setting of throttling elements can throttle, reduce pressure and adjust flow to ensure stable and efficient operation of the control system.

[0026] 7. The setting of PTC heater enables this control system to achieve heating and achieve energy saving under all environmental conditions.

[0027] 8. The setting of the expansion water tank can balance the liquid pressure inside the pipeline and ensure the stable and efficient operation of the control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, wherein: Figure 1 It is a flow chart of the control method in the present invention; Figure 2 It is a structural schematic diagram of the control system in the present invention; Markings in the figure: 1. Battery subsystem, 2. Compressor, 3. Condenser, 4. Plate heat exchanger, 5. Natural air cooling radiator, 6. Solenoid three-way valve, 7. Check valve, 8. Throttling element, 9. PTC heater, 10. Expansion tank, 11. Water pump. DETAILED DESCRIPTION

[0029] Example 1 As a basic embodiment of the present invention, the present invention includes a method for controlling liquid cooling and heating for efficient battery energy storage, comprising the following steps: Step S 1 . Collect parameters, including ambient temperature, operating current and battery cell temperature.

[0030] Step S 2 . Compare the collected parameters with the corresponding thresholds to determine the level of each parameter.

[0031] Step S 3 . Multiply the level of each parameter by the corresponding weight and add them together to get the comprehensive cooling level.

[0032] Step S 4 . Implement corresponding cooling level strategy according to the comprehensive cooling level.

[0033] Example 2 As a preferred embodiment of the present invention, the present invention includes a liquid cooling and heating control method for high-efficiency battery energy storage, comprising the following steps: Step S 1 . Parameters are collected once every preset time period. The parameters include ambient temperature, operating current and battery cell temperature.

[0034] Step S 2 . Compare the collected parameters with the corresponding thresholds and determine the level of each parameter.

[0035] Step S 3 . Multiply the level of each parameter by the corresponding weight and add them together. After rounding using a certain method, the comprehensive cooling level is obtained.

[0036] Step S 4 According to the comprehensive cooling level, by adjusting the control object parameters, the corresponding cooling level strategy is implemented. Wherein, the comprehensive cooling level and the corresponding cooling level strategy can be in a one-to-one correspondence.

[0037] Example 3 As another preferred embodiment of the present invention, the present invention includes a liquid cooling and heat control system for efficient battery energy storage, including a liquid cooling unit subsystem and a battery subsystem 1. The liquid cooling unit subsystem is responsible for providing refrigeration for the battery subsystem 1, including a compressor 2, a condenser 3, a plate heat exchanger 4, a throttling element 8, a natural air cooling radiator 5 and an electromagnetic three-way valve 6. The battery subsystem 1 includes a battery pack, a cold plate is provided in the battery pack, and a flow channel for the flow of coolant inside the cold plate. After the coolant in the cold plate of the battery pack exchanges heat with the battery pack, it passes through the electromagnetic three-way valve 6, exchanges heat with the outside low-temperature air through the natural air cooling radiator 5, and then returns to the cold plate, or exchanges heat with the refrigerant coming out of the compressor 2 and processed by the condenser 3 and the throttling element 8 to become a low-temperature and low-pressure liquid / saturated state through the plate heat exchanger 4, or returns to the cold plate after heat exchange through the plate heat exchanger 4 and the natural air cooling radiator 5 at the same time. Specifically, it can be selected according to actual conditions.

[0038] Example 4 As another preferred embodiment of the present invention, the present invention includes a liquid cooling and heat control system for efficient battery energy storage, including a liquid cooling unit subsystem and a battery subsystem 1. The liquid cooling unit subsystem includes a compressor 2, a condenser 3, a throttling element 8, a plate heat exchanger 4, a natural air cooling radiator 5, an electromagnetic three-way valve 6 and a PTC heater 9. The battery subsystem 1 includes a battery pack and a battery management unit. A cold plate is provided in the battery pack, and a flow channel for the flow of coolant is provided inside the cold plate. Through the refrigeration cycle pipeline, the coolant in the cold plate of the battery pack exchanges heat with the battery pack, passes through the electromagnetic three-way valve 6, and exchanges heat with the low-temperature air outside through the natural air cooling radiator 5 and returns to the cold plate, or / and, exchanges heat with the low-temperature and low-pressure liquid / saturated refrigerant coming out of the compressor 2 and processed by the condenser 3 and the throttling element 8 through the plate heat exchanger 4 and returns to the cold plate. When the battery needs to be heated, the cooling liquid in the cold plate of the battery pack can be heated by the PTC heater 9 through the heating cycle pipeline and then returned to the cold plate. The refrigeration circulation pipeline and the heating circulation pipeline can be independently arranged by respectively arranging corresponding three-way valves at the coolant inlet and outlet of the cold plate. The three-way valve is preferably one whose valve opening can be electronically adjusted.

[0039] The battery management unit comprises: The data acquisition module monitors various parameters in real time, including ambient temperature, battery cell temperature and operating current.

[0040] The decision-making module compares the collected parameters with the corresponding thresholds to determine whether the heating strategy or the cooling strategy needs to be activated. If it is determined that the cooling strategy needs to be executed, the level of each parameter is determined, and the level of each parameter is multiplied by the corresponding weight to obtain the comprehensive cooling level.

[0041] The execution module controls the valve opening of the electromagnetic three-way valve 6 of the three-way valve and the speed of the compressor 2 and / or the speed of the natural air cooling radiator 5 according to the comprehensive cooling level, and implements the corresponding cooling level strategy. Or it controls the parameters of the PTC heater 9 and implements the heating strategy.

[0042] Example 5 As another preferred embodiment of the present invention, refer to the attached specification Figure 2 The present invention includes a liquid cooling and heating control system for efficient battery energy storage, including a liquid cooling unit subsystem, a battery subsystem 1 and a piping subsystem. The liquid cooling unit subsystem is responsible for providing cooling and heating for the battery subsystem 1, including a compressor 2, a condenser 3, a throttling element 8, a plate heat exchanger 4, a natural air cooling radiator 5, a one-way valve 7, an electromagnetic three-way valve 6, a PTC heater 9, a water pump 11 and an expansion water tank 10. The battery subsystem 1 includes a battery pack and a battery management unit. A cold plate is provided in the battery pack, and a flow channel for the flow of coolant is provided inside the cold plate. The cooling or heating of the battery pack is achieved by circulating the coolant, wherein the cold plate is not limited to the bottom or side form.

[0043] The piping subsystem includes a coolant circuit and a refrigerant refrigerant circuit. The coolant circuit includes a coolant outlet pipeline of the cold plate, a natural heat dissipation circulation pipeline, a compression refrigeration pipeline and a coolant inlet pipeline. The water pump 11 is arranged on the coolant inlet pipeline to drive the flow of the liquid working medium and provide the pressure required for the coolant flow to overcome the pipeline resistance. The expansion water tank 10, the PTC heater 9 and the electromagnetic three-way valve 6 are arranged on the coolant outlet pipeline of the cold plate in sequence. Among them, the expansion water tank 10 is used to balance the liquid pressure inside the piping subsystem.

[0044] One end of the electromagnetic three-way valve 6 is connected to the natural heat dissipation circulation pipeline, and one end of the electromagnetic three-way valve 6 is connected to the compression refrigeration pipeline. The other ends of the natural heat dissipation circulation pipeline and the compression refrigeration pipeline are respectively connected to the coolant inlet pipeline of the cold plate. The one-way valve 7 and the natural air cooling radiator 5 are arranged on the natural heat dissipation circulation pipeline in sequence. The plate heat exchanger 4 is arranged on the compression refrigeration pipeline. The compressor 2, the condenser 3 and the throttling element 8 are arranged on the refrigerant refrigerant circuit in sequence, and together with the plate heat exchanger 4 form a refrigerant refrigerant circuit.

[0045] Through the above structure, a refrigeration cycle can be realized, and it includes two: a compression refrigeration cycle and a natural heat dissipation cycle. Specifically, the valve opening of the electromagnetic three-way valve 6 can be electronically adjusted, and then the coolant flow of the compression refrigeration cycle and the natural heat dissipation cycle can be distributed, which can achieve energy saving under all environmental conditions. For example, in a high temperature environment, only the compression refrigeration cycle is turned on; when the ambient temperature is moderate, the two coolant circuits can be turned on at the same time through the electromagnetic three-way valve 6, and the mixed refrigeration mode is turned on, that is, the compression refrigeration cycle and the natural heat dissipation cycle are carried out at the same time; in a low temperature environment, according to the actual battery cooling demand, only the natural heat dissipation cycle can be turned on.

[0046] More specifically, when the compression refrigeration cycle is performed, the high-temperature and high-pressure gaseous refrigerant from the compressor 2 passes through the condenser 3 and the throttling element 8 and becomes a low-temperature and low-pressure liquid / saturated refrigerant. The low-temperature and low-pressure liquid / saturated refrigerant undergoes heat exchange with the high-temperature coolant from the battery pack cold plate in the plate heat exchanger 4, boils and absorbs heat, and then returns to the compressor 2 to continue circulating. The coolant after the heat exchange is again converted into a low-temperature coolant with the ability to absorb heat from the battery, and then returns to the battery pack cold plate to continue circulating.

[0047] When the natural heat dissipation cycle is performed, in the low-temperature environment outside, the high-temperature coolant coming out of the battery pack cold plate after heat exchange with the battery, passes through the one-way valve 7 and flows through the natural air cooling radiator 5, exchanges heat with the low-temperature air outside, and turns into low-temperature coolant with heat absorption capacity with the battery again, and then returns to the cold plate, so that the battery can be cooled by this cycle. The energy consumed by natural heat dissipation is only about 20% of that of compression refrigeration, which greatly improves the energy efficiency ratio of the unit and reduces the refrigeration energy consumption of the unit.

[0048] The above structure can also realize a heating cycle. When the battery needs to be heated, the coolant in the cold plate of the battery pack can be heated by the PTC heater 9 and then returned to the cold plate.

[0049] More specifically, the battery management unit can be used to control the above-mentioned refrigeration cycle and heating cycle, and realize the level formulation and control of the heating strategy and cooling strategy. The battery management unit includes a data acquisition module, a decision-making and judgment module, and an execution module. The data acquisition module can monitor various parameters in real time, including ambient temperature, battery cell temperature, and operating current. The decision-making and judgment module can compare the collected parameters with the corresponding thresholds to determine whether it is necessary to turn on the heating strategy or the cooling strategy. If it is determined that the cooling strategy needs to be executed, the level of each parameter is determined, and the level of each parameter is multiplied by the corresponding weight and added, and the comprehensive cooling level is obtained after rounding. The execution module can control the valve opening of the electromagnetic three-way valve 6 of the three-way valve, the speed of the compressor 2, and the speed of the natural air-cooled radiator 5 according to the comprehensive cooling level, and implement cooling strategies of different levels. Or control the parameters of the PTC heater 9 to implement the heating strategy.

[0050] Example 6 As another preferred embodiment of the present invention, refer to the attached specification Figure 1 The present invention includes a liquid cooling and heating control method for efficient battery energy storage. The control method can be implemented based on the control system in any of the above-mentioned embodiments 3 to 5, or based on other existing control systems. Specifically, it includes the following steps: Step S 1 . Collect parameters at intervals of time t. The parameters include ambient temperature, operating current, and battery cell temperature.

[0051] Step S 2 . Compare the collected parameters with the corresponding thresholds to determine whether the heating strategy or the cooling strategy needs to be activated. Specifically, determine whether the highest cell temperature in the cell temperature is less than or equal to 5°C. If so, it is determined that the heating strategy needs to be activated, and the heating strategy has only one level. If not, it is determined that the cooling strategy needs to be executed, and the level of each parameter is determined.

[0052] For example, from low to high, the ambient temperature, working current and cell temperature all have three levels, namely 1, 2 and 3. When the maximum cell temperature is less than or equal to 27°C, the cell temperature level is 1; when the maximum cell temperature is greater than 27°C and less than or equal to 32°C, the cell temperature level is 2; when the maximum cell temperature is greater than 32°C, the cell temperature level is 3. When the working current is less than or equal to 0.1C, the working current level is 1; when the working current is greater than 0.1C and less than or equal to 0.3C, the working current level is 2; when the working current is greater than 0.3C, the working current level is 3. When the ambient temperature is less than or equal to 25°C, the ambient temperature level is 1; when the ambient temperature is greater than 25°C and less than or equal to 30°C, the ambient temperature level is 2; when the ambient temperature is greater than 30°C, the ambient temperature level is 3.

[0053] Step S 3 . Multiply the level of each parameter by the corresponding weight and then add them together. The result of the addition is rounded off to get the comprehensive cooling level. Among them, the weights of the ambient temperature, working current and battery cell temperature can be 20%, 30% and 50% respectively. The comprehensive cooling level includes level 1, level 2 and level 3.

[0054] Step S 4 . According to the comprehensive cooling level, by adjusting the control object parameters, the corresponding cooling level strategy is implemented to achieve step adjustment.

[0055] The control objects include the speed of the compressor 2, the opening of the electromagnetic three-way valve 6, the speed of the natural air cooling radiator 5, etc. The cooling strategy is divided into 3 levels from high to low according to the liquid supply temperature. The higher the value, the greater the cooling capacity.

[0056] Specifically, when the comprehensive cooling level is less than or equal to level 1, the level 1 cooling strategy is implemented. When the comprehensive cooling level is greater than level 1 and the maximum temperature of the battery cell is less than or equal to 2°C, the level 2 cooling strategy is implemented. When the comprehensive cooling level is greater than level 1 and the maximum temperature of the battery cell is greater than 2°C, the level 3 cooling strategy is implemented. Among them, the level 3 cooling strategy has the lowest supply temperature and is the most energy-consuming. The coolant supply temperature of the unit with level 1 cooling can be 20°C, the coolant supply temperature of the unit with level 2 cooling can be 18°C, and the coolant supply temperature of the unit with level 3 cooling can be 15°C.

[0057] In summary, after reading the present invention document, ordinary technicians in this field can make various other corresponding transformation schemes based on the technical scheme and technical concept of the present invention without creative mental labor, which all fall within the scope of protection of the present invention.

Claims

1. A liquid cooling and heating control method for efficient battery energy storage, characterized in that: The following steps are involved: Step S1. Collecting parameters, the parameters including ambient temperature, operating current and cell temperature; Step S2. Compare the collected parameters with the corresponding thresholds to determine the level of each parameter; Step S3. Multiply the level of each parameter by the corresponding weight and then add them together to obtain a comprehensive cooling level; Step S4. Implement corresponding cooling level strategy according to the comprehensive cooling level.

2. A liquid cooling and heating control method for high-efficiency battery energy storage according to claim 1, characterized in that: When the cell temperature is less than or equal to the corresponding temperature threshold, the heating strategy is turned on.

3. A liquid cooling and heating control method for high-efficiency battery energy storage according to claim 1, characterized in that: The parameters are collected once every preset time period.

4. A liquid cooling and heating control method for high-efficiency battery energy storage according to claim 1, characterized in that: The comprehensive cooling levels include level 1, level 2 and level 3, and the cooling level strategies include level 1 cooling strategy, level 2 cooling strategy and level 3 cooling strategy; when the comprehensive cooling level is level 1, the level 1 cooling strategy is executed; when the comprehensive cooling level is not level 1, the maximum temperature of the battery cell is compared with the preset value. If it is less than or equal to the preset value, the level 2 cooling strategy is executed; if it is greater than the preset value, the level 3 cooling strategy is executed.

5. A liquid cooling and heating control system for efficient battery energy storage, characterized in that: The invention comprises a liquid cooling unit subsystem and a battery subsystem (1), wherein the liquid cooling unit subsystem comprises a compressor (2), a condenser (3), a plate heat exchanger (4), a throttling element (8), a natural air cooling radiator (5) and an electromagnetic three-way valve (6); the battery subsystem (1) comprises a battery pack, wherein a cold plate is provided in the battery pack, and a flow channel for the flow of coolant is provided inside the cold plate; after the coolant in the cold plate of the battery pack exchanges heat with the battery pack, the coolant passes through the electromagnetic three-way valve (6), exchanges heat with the outside low-temperature air through the natural air cooling radiator (5), and then returns to the cold plate; or / and, exchanges heat with the low-temperature and low-pressure liquid / saturated refrigerant that comes out of the compressor (2) and passes through the condenser (3) and the throttling element (8) through the plate heat exchanger (4), and then returns to the cold plate.

6. A liquid cooling and heating control system for high-efficiency battery energy storage according to claim 5, characterized in that: The battery subsystem (1) further comprises a battery management unit, wherein the battery management unit comprises: A data acquisition module monitors various parameters in real time, including ambient temperature, battery cell temperature and operating current; The decision-making module compares the collected parameters with the corresponding thresholds, determines the level of each parameter, and multiplies the level of each parameter with the corresponding weight to obtain the comprehensive cooling level; The execution module controls the valve opening of the electromagnetic three-way valve (6) and the speed of the compressor (2) and / or the speed of the natural air cooling radiator (5) according to the comprehensive cooling level, and implements the corresponding cooling level strategy.

7. The liquid cooling and heating control system for high-efficiency battery energy storage according to claim 6 is characterized in that: A one-way valve (7) is provided between the electromagnetic three-way valve (6) and the natural air cooling radiator (5).

8. The liquid cooling and heating control system for high-efficiency battery energy storage according to claim 6 is characterized in that: A PTC heater (9) for heating the coolant is also included.

9. The liquid cooling and heating control system for high-efficiency battery energy storage according to claim 6, characterized in that: It also includes an expansion water tank (10).

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