Parameter determination method and device of liquid cooling unit

Abstract

The invention discloses a parameter determination method and device of a liquid cooling unit. The method comprises the steps that the liquid outlet temperature of the liquid cooling unit is set to change from the minimum set temperature to the maximum set temperature, and the flow of the liquid cooling unit is set to change from the minimum set flow to the maximum set flow; wherein any set temperature and any set flow form a parameter group; under each parameter group, controlling a battery cell in a single liquid-cooled battery pack to charge and discharge according to a preset operation condition parameter; determining a flow lower limit of the liquid cooling unit and a liquid outlet temperature upper limit corresponding to each set flow according to the temperature parameter of the battery cell in the charging and discharging process, and determining a flow upper limit of the liquid cooling unit according to the temperature variation amplitude of the battery cell in the charging and discharging process; determining the target flow of the liquid cooling unit according to the flow upper limit and the flow lower limit, and determining the target refrigerating capacity of the liquid cooling unit according to the liquid outlet temperature upper limit. According to the technical scheme, the parameters of the liquid cooling unit can be determined more reasonably and accurately.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to a method and device for determining parameters of a liquid cooling unit. Background Art

[0002] To ensure that lithium batteries in energy storage systems operate within a suitable temperature range and remove a large amount of heat generated by the batteries during the charging and discharging process, cold plate liquid cooling systems have gradually become the mainstream application solution for energy storage systems.

[0003] The energy storage system includes a thermal management subsystem, which consists of a heat exchanger, a liquid cooling unit on the primary side of the heat exchanger, and a liquid cooling plate on the secondary side. The liquid cooling plate and the battery pack form a liquid-cooled battery pack. The heat exchanger exchanges heat between the primary cooling capacity and the battery heat removed by the coolant flowing through the secondary liquid cooling plate. Therefore, under actual operating conditions, the cooling capacity of the liquid cooling unit must be matched to the heat removed by the liquid cooling plate. Therefore, during the design phase, the parameters of the liquid cooling unit must be determined and the type of unit selected must be carefully selected.

[0004] In a related technology, according to the average heat generation power P of a single cell cell-heating , calculate the heat generation power P of all cells in a single liquid-cooled battery pack pack-heating , and then accumulate the total heat generation power P of the energy storage system system-heating Assuming that all the heat generated by the system is taken away by the liquid cooling system, the total cooling power of the liquid cooling system is P system-cooling , then P system-heating =P system-cooling Usually in actual selection, the first selection coefficient k1 is set to appropriately expand the cooling capacity to determine the cooling capacity of the liquid cooling unit, that is, the cooling capacity P of the liquid cooling unit. cooling-capacity =k1×P system-cooling Assume that the temperature difference between the outlet and return liquid of the liquid cooling unit is ΔT coolant , through the formula P cooling-capacity =c1×m1×ΔT coolant Calculate the system flow Where c1 is the specific heat capacity of the coolant, and m1 is the coolant mass flow rate, which determines the flow rate of the liquid cooling unit. This method is a steady-state calculation method, assuming that the battery cell, acting as a heat source, generates heat over a long period of time. Eventually, heat generation and heat dissipation balance, with all heat removed by the liquid cooling system, and the cell temperature reaches equilibrium. Selecting a model with cooling capacity greater than heat generation is a completely redundant approach, ignoring the fact that battery cells do not generate heat indefinitely. In actual operation, there are long periods of wasted cooling capacity, resulting in high auxiliary power consumption and high costs.

[0005] In another related technology, according to the average heat generation power P of a single cell cell-heating , calculate the heat generation power P of all cells in a single liquid-cooled battery pack pack-heating, and then accumulate the total heat generation power P of the energy storage system system-heating Considering that the actual battery cell charging and discharging process is staged, it is assumed that part of the heat generated by the battery cell is taken away by the coolant in the liquid cooling plate, causing the coolant temperature to rise, and the other part is absorbed by the battery cell, causing the battery cell temperature to rise. Therefore, it is assumed that in the total charge and discharge cycle time t, the total temperature rise of the system battery cell is ΔT cell , then the total heat absorbed by the battery cell is Q cell-absorbing =c2×m2×ΔT cell , the total heat absorption power of the battery cell is Where c2 is the specific heat capacity of the battery cell, and m2 is the mass of the battery cell. The heat P taken away by the liquid cooling system system-cooling =P system-heating -P cell-absorbing Usually in actual selection, the second selection coefficient k2 is set, the cooling capacity is appropriately expanded, and the final cooling capacity selection is obtained, that is, the cooling capacity P of the liquid cooling unit. cooling-capacity =k2×P system-cooling Assume that the temperature difference between the outlet and return liquid of the liquid cooling unit is ΔT coolant , through the formula P cooling-capacity =c1×m1×ΔT coolant Calculate the system flow Where c1 is the specific heat capacity of the coolant and m1 is the mass flow rate of the coolant, which determines the flow rate of the liquid cooling unit. This method takes into account the heat absorption of the battery cell under actual operating conditions, and the selection and definition of cooling capacity is more reasonable. However, the cooling capacity obtained in the calculation process is a constant value based on the time average, and does not consider that the cooling capacity input actually changes with the heat exchange capacity of the dynamic liquid cold plate. The temperature rise value ΔT of the battery cell during the actual charge and discharge cycle cell It is also affected by the heat exchange capacity of the liquid cooling plate. At the same time, this value is a key factor affecting the final cooling capacity and flow selection. Therefore, this value cannot be assumed in a simple and rough form.

[0006] Therefore, the existing method for determining the parameters of the liquid cooling unit cannot accurately and reasonably determine the parameters of the liquid cooling unit. Summary of the Invention

[0007] The present invention provides a method and device for determining parameters of a liquid cooling unit, so as to solve the problem that the existing method for determining parameters of a liquid cooling unit cannot accurately and reasonably determine the parameters of the liquid cooling unit.

[0008] According to one aspect of the present invention, a method for determining parameters of a liquid cooling unit is provided. The liquid cooling unit is applied to a thermal management subsystem of an energy storage system. The liquid cooling unit is connected to one side of a heat exchanger, and the other side of the heat exchanger is connected to at least one liquid-cooled battery pack. The liquid-cooled battery pack includes at least one battery cell. The method comprises:

[0009] Setting the outlet temperature of the liquid cooling unit to change from a minimum set temperature to a maximum set temperature, and setting the flow rate of the liquid cooling unit to change from a minimum set flow rate to a maximum set flow rate; wherein any one of the set temperatures and any one of the set flows form a parameter group;

[0010] Under each parameter group, controlling the battery cells in a single liquid-cooled battery pack to charge and discharge according to preset operating condition parameters;

[0011] Determine the lower flow limit of the liquid cooling unit and the upper limit of the liquid outlet temperature corresponding to each set flow rate according to the temperature parameters of the battery cell during charging and discharging, and determine the upper limit of the flow rate of the liquid cooling unit according to the temperature change amplitude of the battery cell during charging and discharging;

[0012] The target flow rate of the liquid cooling unit is determined according to the flow rate upper limit and the flow rate lower limit, and the target cooling capacity of the liquid cooling unit is determined according to the liquid outlet temperature upper limit.

[0013] Optionally, determining the lower flow limit of the liquid cooling unit and the upper limit of the liquid outlet temperature corresponding to each set flow rate according to the temperature parameters of the battery cell during the charging and discharging process, and determining the upper limit of the flow rate of the liquid cooling unit according to the temperature change amplitude of the battery cell during the charging and discharging process, includes:

[0014] The minimum flow rate of the liquid cooling unit corresponding to when the temperature parameter of the battery cell meets the temperature control condition during charging and discharging is used as the lower flow limit of the liquid cooling unit, and the minimum flow rate of the liquid cooling unit corresponding to when the temperature change amplitude of the battery cell reaches the temperature control limit condition during charging and discharging is used as the upper flow limit of the liquid cooling unit;

[0015] The minimum outlet liquid temperature of the liquid cooling unit corresponding to each set flow rate when the temperature parameter of the battery cell does not meet the temperature control condition during the charging and discharging process is used as the upper limit of the outlet liquid temperature corresponding to each set flow rate.

[0016] Optionally, the temperature parameters of the battery cell during the charging and discharging process meet temperature control conditions, including:

[0017] The maximum temperature of the battery cell during charging and discharging is less than a first preset temperature, and the difference between the maximum sampling temperature and the minimum sampling temperature of all sampling points on the battery cell is less than a second preset temperature;

[0018] The temperature change of the battery cell during the charge and discharge process reaches the temperature control limit condition, including:

[0019] At the same set temperature, the difference between the maximum temperature of the battery cell during the charging and discharging process at the current set flow rate and the maximum temperature of the battery cell during the charging and discharging process at the previous set flow rate is less than a third preset temperature; wherein the current set flow rate is greater than the previous set flow rate.

[0020] Optionally, determining a target flow rate of the liquid cooling unit according to the flow rate upper limit and the flow rate lower limit, and determining a target cooling capacity of the liquid cooling unit according to the liquid outlet temperature upper limit includes:

[0021] The product of the flow rate upper limit and the number of liquid-cooled battery packs in the thermal management subsystem is used as the target flow rate of the liquid cooling unit;

[0022] Any temperature lower than the upper limit of the liquid outlet temperature corresponding to the target flow rate is used as the target liquid outlet temperature of the liquid cooling unit, and the target cooling capacity of the liquid cooling unit is determined according to the target liquid outlet temperature.

[0023] Optionally, before determining the target cooling capacity of the liquid cooling unit according to the target liquid outlet temperature, the method further includes:

[0024] Determining the peak heat exchange power of the liquid cooling plate corresponding to each parameter group when the temperature parameters of the battery cell during charging and discharging meet the temperature control conditions;

[0025] Determining a target cooling capacity of the liquid cooling unit according to the target liquid outlet temperature includes:

[0026] The target cooling capacity of the liquid cooling unit is determined according to the target liquid outlet temperature and the peak heat exchange power of the liquid cooling plate.

[0027] Optionally, when determining that the temperature parameters of the battery cell during the charging and discharging process meet the temperature control conditions, the peak value of the heat exchange power of the liquid cooling plate corresponding to each parameter group includes:

[0028] When determining that the temperature parameters of the battery cell during the charge and discharge process meet the temperature control conditions, during the charge and discharge period, the maximum return liquid temperature of the liquid cooling unit corresponding to each of the liquid outlet temperatures;

[0029] Under each parameter group, calculating the peak temperature difference between the liquid outlet temperature and the maximum liquid return temperature;

[0030] The product of the specific heat capacity of the coolant in the liquid cooling unit, the temperature difference peak corresponding to each parameter group and the set flow rate is used as the peak heat exchange power of the liquid cooling plate.

[0031] Optionally, the step of setting any temperature that is lower than the upper limit of the liquid outlet temperature corresponding to the target flow rate as the target liquid outlet temperature of the liquid cooling unit includes:

[0032] The previous set temperature of the upper limit of the liquid outlet temperature corresponding to the upper limit of the flow rate is used as the target liquid outlet temperature;

[0033] Determining a target cooling capacity of the liquid cooling unit according to the target liquid outlet temperature and the peak heat exchange power of the liquid cooling plate includes:

[0034] The product of the peak heat exchange power of the liquid cooling plate corresponding to the target liquid outlet temperature and the flow upper limit and the number of liquid-cooled battery packs in the thermal management subsystem is used as the first cooling power; the sum of the first cooling power and the cooling capacity margin is used as the minimum target cooling capacity of the liquid cooling unit.

[0035] Optionally, before taking the sum of the first cooling power and the cooling capacity margin as the minimum target cooling capacity of the liquid cooling unit, the method further includes:

[0036] The cooling capacity margin is determined based on the total heat transfer coefficient of the cabin of the energy storage system where the thermal management subsystem is located, the convection heat transfer coefficient, the thickness of the insulation material of the cabin, the thermal conductivity of the insulation material of the cabin, the ambient temperature difference of the energy storage system, the solar radiation intensity, the surface area of ​​the energy storage system and the shortwave absorption rate of the energy storage system.

[0037] Optionally, before setting the outlet temperature of the liquid cooling unit to change gradually from the minimum set temperature to the maximum set temperature, the method further includes:

[0038] The preset operating condition parameters of the energy storage system where the liquid cooling unit is located are set; wherein the preset operating condition parameters at least include the charge and discharge rate, the number of charge and discharge times, and the time interval between the charging process and the discharging process.

[0039] According to another aspect of the present invention, a device for determining parameters of a liquid cooling unit is provided. The liquid cooling unit is applied to a thermal management subsystem of an energy storage system. The liquid cooling unit is connected to one side of a heat exchanger, and the other side of the heat exchanger is connected to at least one liquid-cooled battery pack. The liquid-cooled battery pack includes at least one battery cell. The device for determining parameters of the liquid cooling unit includes:

[0040] a parameter setting module, configured to set the outlet temperature of the liquid cooling unit from a minimum set temperature to a maximum set temperature, and to set the flow rate of the liquid cooling unit from a minimum set flow rate to a maximum set flow rate; wherein any one of the set temperatures and any one of the set flows form a parameter group;

[0041] A charge and discharge control module, configured to control the battery cells in a single liquid-cooled battery pack to charge and discharge according to preset operating parameters under each parameter group;

[0042] A first parameter determination module is used to determine the lower flow limit of the liquid cooling unit and the upper limit of the liquid outlet temperature corresponding to each set flow rate according to the temperature parameters of the battery cell during charging and discharging, and to determine the upper limit of the flow rate of the liquid cooling unit according to the temperature change amplitude of the battery cell during charging and discharging;

[0043] The second parameter determination module is used to determine the target flow rate of the liquid cooling unit according to the upper flow rate limit and the lower flow rate limit, and determine the target cooling capacity of the liquid cooling unit according to the upper liquid outlet temperature limit.

[0044] According to another aspect of the present invention, an electronic device is provided, comprising:

[0045] at least one processor; and

[0046] a memory communicatively connected to the at least one processor; wherein,

[0047] The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the method for determining parameters of a liquid cooling unit according to any embodiment of the present invention.

[0048] According to another aspect of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the method for determining parameters of a liquid cooling unit according to any embodiment of the present invention when executed.

[0049] According to another aspect of the present invention, a computer program product is provided. The computer program product includes a computer program. When the computer program is executed by a processor, the method for determining parameters of a liquid cooling unit according to any embodiment of the present invention is implemented.

[0050] The technical solution of the embodiment of the present invention is to control the battery cells in a single liquid-cooled battery pack to charge and discharge according to the preset operating condition parameters under each parameter group. The lower flow limit of the liquid cooling unit and the upper limit of the liquid outlet temperature corresponding to each set flow are determined according to the temperature parameters of the battery cells during the charging and discharging process, and the upper limit of the flow of the liquid cooling unit is determined according to the temperature change amplitude of the battery cells during the charging and discharging process. Therefore, the parameters of the liquid cooling unit can be determined according to the specific temperature control requirements, so that the parameters of the liquid cooling unit can be determined more reasonably and accurately. In addition, by determining the target cooling capacity of the liquid cooling unit according to the upper limit of the liquid outlet temperature, the temperature of the coolant output by the liquid cooling unit will not be too low, and redundancy of cooling capacity can be avoided, thereby reducing power consumption and costs, and achieving more reasonable and accurate determination of the parameters of the liquid cooling unit.

[0051] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0053] Figure 1 is a schematic structural diagram of a thermal management subsystem provided by an embodiment of the present invention;

[0054] Figure 2 This is a flow chart of a method for determining parameters of a liquid cooling unit provided by an embodiment of the present invention;

[0055] Figure 3 is a flow chart of another method for determining parameters of a liquid cooling unit provided by an embodiment of the present invention;

[0056] Figure 4 This is a flow chart of another method for determining parameters of a liquid cooling unit provided by an embodiment of the present invention;

[0057] Figure 5 This is a flow chart of another method for determining parameters of a liquid cooling unit provided by an embodiment of the present invention;

[0058] Figure 6 This is a flow chart of another method for determining parameters of a liquid cooling unit provided by an embodiment of the present invention;

[0059] Figure 7 This is a curve diagram showing the change in return liquid temperature of the liquid cooling unit during the charging and discharging process of the battery cell corresponding to the flow rate upper limit and the target liquid outlet temperature provided in an embodiment of the present invention;

[0060] Figure 8 This is a real-time heat exchange power curve of the liquid cooling plate corresponding to the flow upper limit and the target liquid outlet temperature provided by an embodiment of the present invention;

[0061] Figure 9 1 is a schematic structural diagram of a device for determining parameters of a liquid cooling unit provided by an embodiment of the present invention;

[0062] Figure 10 It is a structural diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0063] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0064] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0065] The embodiment of the present invention provides a method for determining parameters of a liquid cooling unit, which can be executed by a parameter determination device for a liquid cooling unit. The liquid cooling unit is applied to the thermal management subsystem of the energy storage system. Figure 1 This is a schematic diagram of the structure of a thermal management subsystem provided by an embodiment of the present invention, referring to Figure 1 The thermal management subsystem includes a liquid cooling unit 110, a heat exchanger 120 and a liquid-cooled battery pack 130. The liquid cooling unit 110 is connected to one side of the heat exchanger 120, and the other side of the heat exchanger 120 is connected to at least one liquid-cooled battery pack 130; the liquid-cooled battery pack 130 includes at least one battery cell.

[0066] Among them, the liquid cooling unit 110 is the core equipment of the thermal management subsystem. The liquid cooling unit 110 can transfer heat from the cooling liquid to the external environment to keep the cooling liquid within a certain temperature range. The liquid cooling unit 110 may include a compressor, a condenser, and an evaporator, etc., which are not limited in this embodiment. The liquid-cooled battery pack 130 includes a liquid cooling plate and a battery pack, and the battery pack includes at least one battery cell. The flow of coolant inside the liquid cooling plate can take away the heat generated by the battery cell. The heat exchanger 120 can perform heat exchange and transfer heat from the hot fluid to the cold fluid, that is, the coolant in the liquid cooling plate that absorbs the heat of the battery cell is transferred to the liquid cooling unit 110. The liquid cooling unit 110 cools down and then outputs it to the liquid cooling plate to achieve circulating refrigeration, thereby reducing the temperature of the battery cell and preventing the battery cell from overheating and damage.

[0067] Figure 2This is a flow chart of a method for determining parameters of a liquid cooling unit provided by an embodiment of the present invention, with reference to Figure 2 , the parameter determination method of the liquid cooling unit includes:

[0068] S101. Setting the outlet temperature of the liquid cooling unit from the minimum set temperature to the maximum set temperature, and setting the flow rate of the liquid cooling unit from the minimum set flow rate to the maximum set flow rate; wherein any set temperature and any set flow rate form a parameter group.

[0069] The outlet temperature of the liquid cooling unit 110 is the temperature of the coolant output from the liquid cooling unit 110 through the heat exchanger 120, i.e., the inlet temperature (return temperature) of the coolant to the liquid-cooled battery pack 130. The cooling power of the liquid cooling unit 110 is related to the temperature difference between the outlet temperature and the return temperature of the liquid cooling unit 110. By setting the outlet temperature of the liquid cooling unit 110, the cooling power of the liquid cooling unit 110, and thus the cooling capacity of the liquid cooling unit 110, can be adjusted. The flow rate of the liquid cooling unit 110 is the flow rate of the coolant in the liquid cooling unit 110.

[0070] Specifically, multiple set temperatures and multiple set flow rates can be set. The outlet temperature of the liquid cooling unit 110 is set to change from the minimum set temperature to the maximum set temperature, and the flow rate of the liquid cooling unit 110 is set to change from the minimum set flow rate to the maximum set flow rate. For example, the outlet temperature of the liquid cooling unit 110 is first set to the minimum set temperature, and the flow rate of the liquid cooling unit 110 is set to change from the minimum set flow rate to the maximum set flow rate. Then, the steps of increasing the outlet temperature of the liquid cooling unit 110 and setting the flow rate of the liquid cooling unit 110 from the minimum set flow rate to the maximum set flow rate are cyclically executed until the outlet temperature of the liquid cooling unit 110 reaches the maximum set temperature.

[0071] The outlet temperature of the liquid cooling unit 110 can be set to change gradually from the minimum set temperature to the maximum set temperature, and the flow rate of the liquid cooling unit 110 can be set to change gradually from the minimum set flow rate to the maximum set flow rate.

[0072] For example, if multiple set temperatures are T1, T2, and T3, and multiple set flow rates are L1, L2, and L3, then multiple parameter groups are formed, namely (T1, L1), (T1, L2), (T1, L3), (T2, L1), (T2, L2), (T2, L3), (T3, L1), (T3, L2), and (T3, L3).

[0073] S102. Under each parameter group, control the battery cells in a single liquid-cooled battery pack to charge and discharge according to preset operating condition parameters.

[0074] Specifically, the heat dissipation process of each liquid-cooled battery pack in the energy storage system is relatively independent, so a single liquid-cooled battery pack can be used as a basic unit to determine the parameters of the liquid cooling unit 110 when the single liquid-cooled battery pack is charged and discharged, and thus the parameters of the liquid cooling unit 110 corresponding to the entire energy storage system can be determined.

[0075] Controlling the charging and discharging of the cells in the liquid-cooled battery pack 130, i.e., controlling the charge and discharge cycles of the cells in the liquid-cooled battery pack 130, wherein the specific number of cycles is determined based on preset operating condition parameters. The preset operating condition parameters can be determined based on the actual application scenario of the liquid-cooled battery pack, and this embodiment does not limit these parameters. In this way, the parameters of the liquid cooling unit 110 can be determined based on the actual operating conditions of the liquid-cooled battery pack 130, which can improve the dynamics of the parameter determination of the liquid cooling unit 110 and facilitate improving the reliability, rationality, and accuracy of the parameter determination of the liquid cooling unit 110.

[0076] For example, the outlet temperature of the liquid cooling unit 110 is first set to the minimum set temperature, the flow rate of the liquid cooling unit 110 is set to the minimum set flow rate, and the battery cells in the individual liquid-cooled battery pack are controlled to perform a charge-discharge cycle according to the preset operating parameters. Then, the flow rate of the liquid cooling unit 110 is cyclically increased to the next set flow rate, and the battery cells in the individual liquid-cooled battery pack are controlled to perform a charge-discharge cycle according to the preset operating parameters until the flow rate of the liquid cooling unit 110 reaches the maximum set flow rate. The following cycle is repeated: the outlet temperature of the liquid cooling unit 110 is increased to the next set temperature, the flow rate of the liquid cooling unit 110 is set to the minimum set flow rate, and the battery cells in the individual liquid-cooled battery pack are controlled to perform a charge-discharge cycle according to the preset operating parameters. Then, the flow rate of the liquid cooling unit 110 is cyclically increased to the next set flow rate, and the battery cells in the individual liquid-cooled battery pack are controlled to perform a charge-discharge cycle according to the preset operating parameters until the flow rate of the liquid cooling unit 110 reaches the maximum set flow rate. This cycle continues until the outlet temperature of the liquid cooling unit 110 reaches the maximum set temperature. In this way, under each parameter group, the battery cells in a single liquid-cooled battery pack are controlled to charge and discharge according to the preset operating parameters, completing the orthogonal experiment.

[0077] It should be noted that the control of charging and discharging of a single liquid-cooled battery pack can be carried out through actual measurement or simulation, and this embodiment does not limit this.

[0078] S103, determining the flow lower limit of the liquid cooling unit and the upper limit of the liquid outlet temperature corresponding to each set flow rate according to the temperature parameters of the battery cell during the charging and discharging process, and determining the flow upper limit of the liquid cooling unit according to the temperature change amplitude of the battery cell during the charging and discharging process.

[0079] Specifically, during the charge and discharge process of the battery cell, the temperature parameters of the battery cell are obtained, the lower limit of the flow of the liquid cooling unit is determined based on the temperature parameters of the battery cell, and the upper limit of the flow of the liquid cooling unit 110 is determined based on the temperature change amplitude of the battery cell during the charge and discharge process. Then, the flow range can be determined, and thus the target flow of the liquid cooling unit can be determined based on the lower and upper flow limits. That is, based on the temperature control requirements of the battery cell and the resistance of the coolant, a flow value between the lower and upper flow limits is selected as the target flow of the coolant of the liquid cooling unit. The upper limit of the outlet liquid temperature corresponding to each set flow rate is determined based on the temperature parameters of the battery cell during the charge and discharge process. That is, each set flow rate can correspond to an upper limit of the outlet liquid temperature. The outlet liquid temperature of the liquid cooling unit 110 can be determined based on the upper limit of the outlet liquid temperature corresponding to the selected final flow rate.

[0080] In this way, the lower and upper flow limits required by the liquid cooling unit 110 can be determined according to the actual charging and discharging process of the battery cell, and the upper limit of the liquid outlet temperature of the liquid cooling unit 110 corresponding to each set flow rate can be determined. Therefore, the parameters of the liquid cooling unit 110 can be determined according to specific temperature control requirements, so that the parameters of the liquid cooling unit 110 can be determined more reasonably and accurately.

[0081] S104: Determine a target flow rate of the liquid cooling unit according to the upper flow rate limit and the lower flow rate limit, and determine a target cooling capacity of the liquid cooling unit according to the upper liquid outlet temperature limit.

[0082] Specifically, the target flow rate of the liquid cooling unit can be determined based on the value between the lower flow rate limit and the upper flow rate limit, and the target outlet temperature of the liquid cooling unit 110 can be determined based on the upper limit of the outlet temperature of the liquid cooling unit 110 corresponding to the target flow rate. The target cooling capacity of the liquid cooling unit 110 can then be determined based on the target outlet temperature. In this way, the target flow rate and target cooling capacity of the liquid cooling unit 110 can be determined, and the parameters of the liquid cooling unit 110 can be determined, that is, the type selection of the liquid cooling unit 110 can be achieved. By determining the target cooling capacity of the liquid cooling unit 110 based on the upper limit of the outlet temperature, the temperature of the coolant output by the liquid cooling unit 110 can be prevented from being too low, and redundant cooling capacity can be avoided, thereby reducing power consumption and costs, and achieving more reasonable and accurate determination of the parameters of the liquid cooling unit 110.

[0083] The technical solution of this embodiment controls the charging and discharging of the battery cells in a single liquid-cooled battery pack according to preset operating parameters under each parameter group. The lower flow limit of the liquid cooling unit and the upper limit of the liquid outlet temperature corresponding to each set flow rate are determined based on the temperature parameters of the battery cells during the charging and discharging process, and the upper limit of the flow rate of the liquid cooling unit is determined based on the temperature change amplitude of the battery cells during the charging and discharging process. This allows the parameters of the liquid cooling unit to be determined according to specific temperature control requirements, thereby enabling the parameters of the liquid cooling unit to be determined more reasonably and accurately. In addition, by determining the target cooling capacity of the liquid cooling unit based on the upper limit of the liquid outlet temperature, the temperature of the coolant output by the liquid cooling unit will not be too low, and redundancy in cooling capacity can be avoided, thereby reducing power consumption and costs, and achieving more reasonable and accurate determination of the parameters of the liquid cooling unit.

[0084] On the basis of the above technical solutions, Figure 3 This is a flow chart of another method for determining parameters of a liquid cooling unit provided by an embodiment of the present invention. Optionally, refer to Figure 3 , the parameter determination method of the liquid cooling unit includes:

[0085] S201. Set the outlet temperature of the liquid cooling unit from the minimum set temperature to the maximum set temperature, and set the flow rate of the liquid cooling unit from the minimum set flow rate to the maximum set flow rate; wherein any set temperature and any set flow rate form a parameter group.

[0086] S202. Under each parameter group, control the battery cells in a single liquid-cooled battery pack to charge and discharge according to preset operating condition parameters.

[0087] S203. The minimum flow rate of the liquid cooling unit corresponding to when the temperature parameters of the battery cells during charging and discharging meet the temperature control conditions is used as the lower flow limit of the liquid cooling unit. The minimum flow rate of the liquid cooling unit corresponding to when the temperature change amplitude of the battery cells during charging and discharging reaches the temperature control limit conditions is used as the upper flow limit of the liquid cooling unit.

[0088] Specifically, when the temperature parameters of the battery cells during the charging and discharging process meet the temperature control conditions, that is, when the temperature of the battery cells is relatively low, the corresponding minimum flow rate of the liquid cooling unit 110 is the lower flow limit of the liquid cooling unit 110, so that the determined lower flow limit meets the temperature control requirements of the battery cells. When the temperature variation of the battery cells during the charging and discharging process reaches the temperature control limit condition, that is, when the temperature variation of the battery cells during the charging and discharging process is relatively low, that is, when changing the flow rate has little effect on the temperature of the battery cells, the corresponding minimum flow rate of the liquid cooling unit 110 is used as the upper flow limit of the liquid cooling unit 110. Determining the parameters of the liquid cooling unit 110 based on the upper flow limit can avoid flow redundancy and help reduce power consumption and costs.

[0089] For example, when the outlet temperature of the liquid cooling unit 110 is at any set temperature, the flow rate of the liquid cooling unit 110 can be set to change from a minimum set flow rate to a maximum set flow rate, and at each set flow rate, a single liquid-cooled battery pack 130 can be controlled to perform a charge and discharge cycle. The temperature parameters of the battery cells during the charge and discharge process are obtained for each charge and discharge cycle. The flow rate corresponding to the first time the temperature parameters of the battery cells during the charge and discharge process meet the temperature control conditions is the minimum flow rate of the liquid cooling unit 110 corresponding to the temperature parameters of the battery cells during the charge and discharge process. The flow rate corresponding to the first time the temperature change amplitude of the battery cells during the charge and discharge process meets the temperature control limit conditions is the minimum flow rate of the liquid cooling unit 110 corresponding to the temperature change amplitude of the battery cells during the charge and discharge process. This process is repeated to obtain the minimum flow rate of the liquid cooling unit 110 corresponding to the temperature parameters of the battery cells during the charge and discharge process meeting the temperature control conditions at each set temperature. The minimum value of the minimum flow rates of all determined minimum flow rates when the temperature parameters of the battery cells during the charge and discharge process meet the temperature control conditions is the lower limit of the flow rate of the liquid cooling unit 110. This process is repeated to determine the minimum flow rate of the liquid cooling unit 110 at each set temperature when the temperature variation of the battery cells during the charge and discharge process meets the temperature control limit. The minimum value of all the minimum flow rates determined when the temperature variation of the battery cells during the charge and discharge process meets the temperature control limit is the upper flow rate limit of the liquid cooling unit 110. This allows the upper and lower flow rates of the liquid cooling unit 110 to be determined.

[0090] S204 , when the temperature parameter of the battery cell during the charge and discharge process does not meet the temperature control condition, the minimum outlet temperature of the liquid cooling unit corresponding to each set flow rate is used as the upper limit of the outlet temperature corresponding to each set flow rate.

[0091] For example, at each set flow rate, the outlet temperature of the liquid cooling unit 110 is set to vary from a minimum set temperature to a maximum set temperature, and at each set temperature, a single liquid-cooled battery pack 130 is controlled to perform a charge and discharge cycle. The temperature parameters of the battery cell during the charge and discharge process are obtained for each charge and discharge cycle. The outlet temperature corresponding to the first time the temperature parameters of the battery cell during the charge and discharge process do not meet the temperature control conditions is the minimum outlet temperature of the liquid cooling unit 110 at the current set flow rate, corresponding to the temperature parameters of the battery cell during the charge and discharge process not meeting the temperature control conditions. This is also the upper limit of the outlet temperature of the liquid cooling unit 110 at the current set flow rate. In this way, the upper limit of the outlet temperature corresponding to each set flow rate can be obtained.

[0092] S205: Determine a target flow rate of the liquid cooling unit according to the upper flow rate limit and the lower flow rate limit, and determine a target cooling capacity of the liquid cooling unit according to the upper liquid outlet temperature limit.

[0093] Based on the above technical solution, the temperature parameters of the battery cells during charging and discharging meet the temperature control conditions, including:

[0094] The maximum temperature of the battery cell during charging and discharging is lower than the first preset temperature, and the difference between the maximum sampling temperature and the minimum sampling temperature of all sampling points on the battery cell is lower than the second preset temperature.

[0095] Specifically, under any parameter group, the maximum temperature of all cells in a single liquid-cooled battery pack 130 during charging and discharging is less than the first preset temperature, indicating that this parameter group enables the operation of the liquid cooling unit 110 to ensure that the maximum temperature of the cells meets the temperature control requirements, that is, the temperature of the cells is effectively controlled. Multiple sampling points are set in a single liquid-cooled battery pack 130, and the difference between the maximum sampling temperature and the minimum sampling temperature of all sampling points is less than the second preset temperature, that is, the difference between the maximum sampling temperature and the minimum sampling temperature is small, that is, the temperature uniformity of the cells in the liquid-cooled battery pack 130 is good, and the temperature control conditions for temperature uniformity are met. In this way, the determined parameters can be used to ensure that the operation of the liquid cooling unit 110 can ensure that the cells meet the temperature control conditions, that is, the temperature of the cells is low and the temperature uniformity is good.

[0096] The first preset temperature may be 40°C, 45°C, any value between 30°C and 45°C, or any value between 20°C and 50°C, and this embodiment is not limited thereto. The second preset temperature may be any value between 1°C and 10°C, or any value between 1°C and 5°C, for example, 3°C, and this embodiment is not limited thereto.

[0097] Optionally, the temperature variation of the battery cell during the charge and discharge process reaches the temperature control limit condition, including:

[0098] At the same set temperature, the difference between the maximum temperature of the battery cell during the charging and discharging process at the current set flow rate and the maximum temperature of the battery cell during the charging and discharging process at the previous set flow rate is less than the third preset temperature; wherein the current set flow rate is greater than the previous set flow rate.

[0099] Specifically, the flow rate of the liquid cooling unit 110 gradually changes from the minimum set flow rate to the maximum set flow rate, so the current set flow rate is greater than the previous set flow rate. If the difference between the maximum temperature of the battery cell during the charging and discharging process at the current set flow rate and the maximum temperature of the battery cell during the charging and discharging process at the previous set flow rate is less than the third preset temperature, it indicates that the outlet temperature of the liquid cooling unit 110 remains unchanged. After the flow rate of the liquid cooling unit 110 increases, the maximum temperature change amplitude of the battery cell during the charging and discharging process of the battery cell is small, that is, the temperature control effect of the battery cell tends to be stable, that is, the temperature change amplitude meets the temperature control limit condition. Among them, the third preset temperature can be 0.05℃-1℃, for example, 0.1℃, which can be determined according to the actual application scenario, and this embodiment is not limited.

[0100] On the basis of the above technical solutions, Figure 4This is a flow chart of another method for determining parameters of a liquid cooling unit provided by an embodiment of the present invention. Optionally, refer to Figure 4 , the parameter determination method of the liquid cooling unit includes:

[0101] S301. Set the outlet temperature of the liquid cooling unit from the minimum set temperature to the maximum set temperature, and set the flow rate of the liquid cooling unit from the minimum set flow rate to the maximum set flow rate; wherein any set temperature and any set flow rate form a parameter group.

[0102] S302 . Under each parameter group, control the battery cells in a single liquid-cooled battery pack to charge and discharge according to preset operating condition parameters.

[0103] S303. The minimum flow rate of the liquid cooling unit corresponding to when the temperature parameters of the battery cells during charging and discharging meet the temperature control conditions is used as the lower flow limit of the liquid cooling unit. The minimum flow rate of the liquid cooling unit corresponding to when the temperature change amplitude of the battery cells during charging and discharging reaches the temperature control limit conditions is used as the upper flow limit of the liquid cooling unit.

[0104] S304 , when the temperature parameter of the battery cell during the charge and discharge process does not meet the temperature control condition, the minimum outlet temperature of the liquid cooling unit corresponding to each set flow rate is used as the upper limit of the outlet temperature corresponding to each set flow rate.

[0105] S305 : The product of the flow rate upper limit and the number of liquid-cooled battery packs in the thermal management subsystem is used as the target flow rate of the liquid cooling unit.

[0106] Specifically, in the thermal management subsystem, the liquid cooling plate within each liquid-cooled battery pack 130 is connected to the liquid cooling unit 110 via system piping. When selecting parameters for the liquid cooling unit 110, a cumulative effect exists. Therefore, the target flow rate for the liquid cooling unit can be determined by multiplying the flow limit by the number of liquid-cooled battery packs in the thermal management subsystem. Furthermore, the flow limit is selected as the average flow rate for the liquid-cooled battery pack 130. At this flow limit, the temperature control effect on the battery cells is stable and insensitive to flow rate variations. This ensures that even if there are differences in flow distribution between the liquid cooling plates of the liquid-cooled battery packs 130 within the thermal management subsystem, significant temperature differences between the battery cells within different packs caused by this flow distribution issue can be avoided, effectively improving the temperature uniformity of the thermal management subsystem.

[0107] S306. Taking any temperature lower than the upper limit of the liquid outlet temperature corresponding to the target flow rate as the target liquid outlet temperature of the liquid cooling unit, and determining the target cooling capacity of the liquid cooling unit according to the target liquid outlet temperature.

[0108] Specifically, after determining the target flow rate, the upper limit of the liquid outlet temperature corresponding to the target flow rate can be used as the final upper limit of the liquid outlet temperature of the liquid cooling unit 110. The target liquid outlet temperature can be lower than the final upper limit. For example, any set temperature that is lower than the upper limit of the liquid outlet temperature corresponding to the target flow rate can be used as the target liquid outlet temperature of the liquid cooling unit. Based on the target liquid outlet temperature and the return liquid temperature of the liquid cooling unit 110, the target cooling capacity of the liquid cooling unit 110 can be determined. In this way, the parameters of the liquid cooling unit 110 can be determined, and the type of the liquid cooling unit 110 can be selected.

[0109] Based on the above technical solution, the method for determining the target cooling capacity is further explained below, but it does not limit the present application.

[0110] Figure 5 This is a flow chart of another method for determining parameters of a liquid cooling unit provided by an embodiment of the present invention. Optionally, refer to Figure 5 , the parameter determination method of the liquid cooling unit includes:

[0111] S401. Set the outlet temperature of the liquid cooling unit from the minimum set temperature to the maximum set temperature, and set the flow rate of the liquid cooling unit from the minimum set flow rate to the maximum set flow rate; wherein any set temperature and any set flow rate form a parameter group.

[0112] S402 : Under each parameter group, control the battery cells in a single liquid-cooled battery pack to charge and discharge according to preset operating condition parameters.

[0113] S403. The minimum flow rate of the liquid cooling unit corresponding to when the temperature parameters of the battery cells during charging and discharging meet the temperature control conditions is used as the lower flow limit of the liquid cooling unit. The minimum flow rate of the liquid cooling unit corresponding to when the temperature change amplitude of the battery cells during charging and discharging reaches the temperature control limit conditions is used as the upper flow limit of the liquid cooling unit.

[0114] S404: When the temperature parameter of the battery cell during the charge and discharge process does not meet the temperature control condition, the minimum outlet temperature of the liquid cooling unit corresponding to each set flow rate is used as the upper limit of the outlet temperature corresponding to each set flow rate.

[0115] S405 : The product of the flow upper limit and the number of liquid-cooled battery packs in the thermal management subsystem is used as the target flow of the liquid cooling unit.

[0116] S406. Any temperature that is lower than the upper limit of the liquid outlet temperature corresponding to the target flow rate is used as the target liquid outlet temperature of the liquid cooling unit.

[0117] S407 , determining the peak value of the heat exchange power of the liquid cooling plate corresponding to each parameter group when the temperature parameters of the battery cell during the charging and discharging process meet the temperature control conditions.

[0118] Specifically, the peak cooling power demand of the liquid cooling unit 110 is the peak heat exchange power of the liquid cooling plate in the liquid-cooled battery pack 130. For example, multiple cooling power demands (heat exchange powers of the liquid cooling plate) can be determined during the charging and discharging process of the battery cell under each parameter group when the battery cell temperature parameters meet the temperature control conditions, thereby obtaining the peak cooling power demand (heat exchange power peak of the liquid cooling plate) corresponding to each parameter group when the battery cell temperature parameters meet the temperature control conditions. Furthermore, by determining the target cooling capacity of the liquid cooling unit 110 based on the peak cooling power demand (heat exchange power peak of the liquid cooling plate), it can be ensured that the determined target cooling capacity ensures that the cooling power of the liquid cooling unit 110 meets the temperature control requirements.

[0119] For example, Table 1 shows the peak heat exchange power of the liquid cooling plate of the liquid cooling unit under different parameter groups, which is the orthogonal data table corresponding to the orthogonal experiment. As shown in Table 1, the set temperatures of the outlet temperature of the liquid cooling unit 110 are T ex2-out，1 、T ex2-out，2 、T ex2-out，3 and T ex2-out，4 The set flow rates of the cooling liquid of the liquid cooling unit 110 are L1, L2, L3, L4, L5...L n , the parameter group includes (T ex2-out，1 , L1), (T ex2-out，1 , L2)……(T ex2-out，1 , L n )、(T ex2-out，2 , L1), (T ex2-out，2 , L2)……(T ex2-out，2 , L n )、(T ex2-out，3 , L1), (T ex2-out，3 , L2)……(T ex2-out，3 , L n )、(T ex2-out，4 , L1), (T ex2-out，4 , L2)……(T ex2-out，4 , L n ).

[0120] Table 1 Peak heat exchange power of liquid cooling plate of liquid cooling unit under different parameter groups

[0121]

[0122]

[0123] As shown in Table 1, when the cooling liquid flow rate of the liquid cooling unit 110 is L1, the battery cells do not meet the temperature control conditions at each set temperature. When the cooling liquid flow rate of the liquid cooling unit 110 is L2, only the set temperature T ex2-out，1 When the cell meets the temperature control conditions, the upper limit of the outlet temperature is T when the flow rate is L2. ex2-out，1, and it can be determined that (T ex2-out，1 , L2) The peak heat exchange power P of the liquid cooling plate corresponding to the parameter group cp,1 Similarly, when the cell temperature parameters meet the temperature control conditions, the corresponding peak heat exchange power of the liquid cooling plate for other parameter groups can be determined. In this way, the peak cooling power requirement (peak heat exchange power of the liquid cooling plate) for each parameter group can be determined when the cell temperature parameters meet the temperature control conditions. In Table 1, j is an integer greater than or equal to 10, and n is an integer greater than 5.

[0124] S408: Determine the target cooling capacity of the liquid cooling unit according to the target liquid outlet temperature and the peak heat exchange power of the liquid cooling plate.

[0125] Specifically, the cooling power requirements of all liquid-cooled battery packs in the thermal management subsystem can be determined based on the peak heat exchange power of the liquid cooling plate of a single liquid-cooled battery pack (peak cooling power demand). Based on the target liquid outlet temperature corresponding to the flow rate of the coolant of the liquid cooling unit 110 at the upper limit of the flow rate and the return liquid temperature of the liquid cooling unit 110, the target temperature difference of the liquid cooling unit 110 (the difference between the target liquid outlet temperature and the corresponding return liquid temperature of the liquid cooling unit 110) can be determined. Based on the target temperature difference, the specific heat capacity of the coolant, and the peak heat exchange power of the liquid cooling plate of all liquid-cooled battery packs (peak cooling power demand), the target cooling capacity of the liquid cooling unit 110 can be determined. In this way, the determined target cooling capacity can meet the temperature control requirements of all liquid-cooled battery packs.

[0126] The technical solution of this embodiment determines the target cooling capacity of the liquid cooling unit based on the target liquid outlet temperature and the peak cooling power demand (peak heat exchange power of the liquid cooling plate). Therefore, the influence of the heat exchange capacity of the liquid cooling plate is taken into account when determining the target cooling capacity. The technical solution of this embodiment can be applied to the design of liquid cooling plates for different liquid-cooled battery packs, which can improve the applicability of the determination of the parameters of the liquid cooling unit, thereby more reasonably and accurately determining the parameters of the liquid cooling unit.

[0127] Based on the above technical solution, optionally, when the temperature parameters of the battery cells during charging and discharging meet the temperature control conditions, the peak value of the heat exchange power of the liquid cooling plate corresponding to each parameter group is determined, including:

[0128] Step a1: When the temperature parameters of the battery cell during the charge and discharge process meet the temperature control conditions, the maximum return liquid temperature of the liquid cooling unit corresponding to each liquid outlet temperature during the charge and discharge period is determined.

[0129] Specifically, under each parameter group, determine whether the temperature parameters of the battery cell during the charging and discharging process meet the temperature control conditions. When it is determined that the temperature parameters of the battery cell during the charging and discharging process meet the temperature control conditions, at each liquid outlet temperature (set temperature) corresponding to when the temperature parameters of the battery cell during the charging and discharging process meet the temperature control conditions, obtain the maximum liquid return temperature of the liquid cooling unit 110 during the entire charging and discharging period, that is, the corresponding liquid return temperature peak value at each liquid outlet temperature (set temperature) corresponding to when the temperature parameters of the battery cell during the charging and discharging process meet the temperature control conditions.

[0130] Step a2: Under each parameter group, calculate the peak value of the temperature difference between the liquid temperature and the maximum return liquid temperature.

[0131] Specifically, when the temperature parameters of the battery cell during the charge and discharge process meet the temperature control conditions, the peak value of the temperature difference between the liquid temperature and the maximum return liquid temperature is calculated. For example, when the temperature parameters of the battery cell during the charge and discharge process meet the temperature control conditions, the maximum return liquid temperature is T ex2-in , the corresponding outlet temperature is T ex2-out , then the peak temperature difference is ΔT coolant，max =T ex2-in -T ex2-out .

[0132] Step a3: The product of the specific heat capacity of the coolant in the liquid cooling unit, the temperature difference peak value corresponding to each parameter group, and the set flow rate is used as the peak heat exchange power of the liquid cooling plate.

[0133] Specifically, when the temperature parameters of the battery cell during the charge and discharge process meet the temperature control conditions, the product of the specific heat capacity of the coolant in the liquid cooling unit, the temperature difference peak value corresponding to each parameter group, and the set flow rate is used as the peak heat exchange power of the liquid cooling plate. For example, the specific heat capacity of the coolant in the liquid cooling unit 110 is c cool , the temperature difference peak value corresponding to any parameter group is ΔT coolant，max , the corresponding set flow is m, then the peak heat transfer power of the liquid cooling plate P cp，max =c cool ×m×T coolant，max In this way, the peak heat exchange power of the liquid cooling plate corresponding to each parameter group can be obtained when the temperature parameters of the battery cell during the charging and discharging process meet the temperature control conditions.

[0134] Optionally, any temperature less than the upper limit of the liquid outlet temperature corresponding to the target flow rate is used as the target liquid outlet temperature of the liquid cooling unit, including:

[0135] The previous set temperature of the upper limit of the liquid outlet temperature corresponding to the upper limit of the flow rate is used as the target liquid outlet temperature.

[0136] Specifically, when the outlet temperature of the liquid cooling unit 110 is at the upper limit of the outlet temperature, it cannot meet the temperature control requirements, and it is the minimum temperature that cannot meet the temperature control requirements. Then, the previous set temperature of the upper limit of the outlet temperature can meet the temperature control requirements. The previous set temperature of the upper limit of the outlet temperature is the set temperature that is closest to the upper limit of the outlet temperature and is less than the upper limit of the outlet temperature. Then, the previous set temperature of the upper limit of the outlet temperature corresponding to the flow rate upper limit can be used as the target outlet temperature. In this way, the target outlet temperature is determined to be relatively high, which can avoid the problem of condensation caused by a low outlet temperature, and the target outlet temperature is relatively high, so that the resistance of the coolant is relatively small and the fluidity is better. In addition, the target outlet temperature is determined to be relatively high, which can avoid a high cooling capacity and a large cooling redundancy, which is conducive to reducing power consumption and cost, and realizing a more reasonable and accurate determination of the parameters of the liquid cooling unit 110.

[0137] Optionally, determining a target cooling capacity of the liquid cooling unit according to a target liquid outlet temperature and a peak heat exchange power of the liquid cooling plate includes:

[0138] Step b1: The product of the peak heat exchange power of the liquid cooling plate corresponding to the target liquid outlet temperature and the flow rate upper limit and the number of liquid-cooled battery packs in the thermal management subsystem is used as the first cooling power.

[0139] Specifically, in the thermal management subsystem, the liquid cooling plate in each liquid-cooled battery pack 130 is connected to the liquid cooling unit 110 through the system pipeline. There is a cumulative effect when selecting the parameters of the liquid cooling unit 110. Therefore, the product of the peak heat exchange power of the liquid cooling plate corresponding to the target liquid outlet temperature and the flow upper limit and the number of liquid-cooled battery packs in the thermal management subsystem can be used as the total cooling demand power, that is, the first cooling power.

[0140] For example, when the flow rate of the coolant of the liquid cooling unit 110 corresponding to a single liquid-cooled battery pack 130 is the upper limit of the flow rate, the peak heat exchange power of the liquid cooling plate corresponding to the target liquid outlet temperature is P cp，max , the number of liquid-cooled battery packs 130 in the thermal management subsystem is i, where i is a positive integer. Then the first cooling power is i×P cp，max .

[0141] Step b2: taking the sum of the first cooling power and the cooling capacity margin as the minimum target cooling capacity of the liquid cooling unit.

[0142] Specifically, the energy storage system will be affected by solar radiation and ambient temperature during its lifecycle. Assuming that the entire cooling load from the external environment is input into the thermal management subsystem, it is ultimately added to the cooling capacity of the thermal management subsystem, which is defined as the cooling capacity margin. Therefore, by using the sum of the first cooling power and the cooling capacity margin as the minimum target cooling capacity of the liquid cooling unit, the cooling capacity of the liquid cooling unit 110 is greater than or equal to the minimum target cooling capacity. This ensures that the liquid cooling unit 110 can meet the temperature control requirements of the battery cells and can offset temperature changes caused by the external environment and solar radiation, thereby ensuring that the cooling capacity of the liquid cooling unit 110 meets the requirements and improving the reliability of the thermal management subsystem.

[0143] For example, the cooling load (cooling capacity margin) of the external environment is P a , then determine the cooling capacity P of the liquid cooling unit 110 cooling ≥i×P cp，max +P a , that is, the minimum target cooling capacity is i×P cp，max +P a .

[0144] Optionally, before taking the sum of the first cooling power and the cooling capacity margin as the minimum target cooling capacity of the liquid cooling unit, the method further includes:

[0145] The cooling capacity margin is determined based on the total heat transfer coefficient of the cabin of the energy storage system where the thermal management subsystem is located, the convection heat transfer coefficient, the thickness of the cabin's insulation material, the thermal conductivity of the cabin's insulation material, the ambient temperature difference of the energy storage system, the solar radiation intensity, the surface area of ​​the energy storage system, and the short-wave absorption rate of the energy storage system.

[0146] For example, the total heat transfer coefficient of the cabin of the energy storage system where the management subsystem is located is K. The convective heat transfer coefficient is the convective heat transfer coefficient of the inner and outer surfaces of the cabin of the energy storage system h a The thickness of the insulation material of the cabin is δ, the thermal conductivity of the insulation material of the cabin is λ, and the ambient temperature difference of the energy storage system is the external maximum ambient temperature T of the energy storage system. a and set the internal ambient temperature T i The difference T a -T i The solar radiation intensity is G, the surface area of ​​the energy storage system is A, the short-wave absorption rate of the energy storage system is the short-wave absorption rate of the outer surface of the energy storage system α, then the cooling load of the external environment P a for In other implementations, the cooling capacity margin may also be determined based on empirical values, which is not limited in this embodiment.

[0147] On the basis of the above technical solutions, Figure 6This is a flow chart of another method for determining parameters of a liquid cooling unit provided by an embodiment of the present invention. Optionally, refer to Figure 6 , the parameter determination method of the liquid cooling unit includes:

[0148] S501. Set preset operating parameters of the energy storage system where the liquid cooling unit is located; wherein the preset operating parameters at least include a charge and discharge rate, a charge and discharge frequency, and a time interval between a charge process and a discharge process.

[0149] Specifically, the preset operating condition parameters can be determined according to the actual application scenario of the thermal management subsystem. For example, the charge and discharge rate can be 0.5C, 1C, or 2C, which is not limited in this embodiment. The time interval between the charging process and the discharging process, that is, the charge and discharge interval, can be 0 hours, 1 hour, 1.5 hours, or 2 hours, which is not limited in this embodiment. The number of charge and discharge times, that is, the number of charge and discharge times corresponding to each parameter group, can be determined according to the actual application scenario of the thermal management system.

[0150] S502. Set the outlet temperature of the liquid cooling unit from the minimum set temperature to the maximum set temperature, and set the flow rate of the liquid cooling unit from the minimum set flow rate to the maximum set flow rate; wherein any set temperature and any set flow rate form a parameter group.

[0151] S503 . Under each parameter group, control the battery cells in a single liquid-cooled battery pack to charge and discharge according to preset operating condition parameters.

[0152] S504. The minimum flow rate of the liquid cooling unit corresponding to when the temperature parameters of the battery cells during charging and discharging meet the temperature control conditions is used as the lower flow limit of the liquid cooling unit. The minimum flow rate of the liquid cooling unit corresponding to when the temperature variation of the battery cells during charging and discharging reaches the temperature control limit conditions is used as the upper flow limit of the liquid cooling unit.

[0153] S505 , when the temperature parameter of the battery cell during the charge and discharge process does not meet the temperature control condition, the minimum outlet temperature of the liquid cooling unit corresponding to each set flow rate is used as the upper limit of the outlet temperature corresponding to each set flow rate.

[0154] S506: The product of the flow rate upper limit and the number of liquid-cooled battery packs in the thermal management subsystem is used as the target flow rate of the liquid cooling unit.

[0155] S507. Any temperature lower than the upper limit of the liquid outlet temperature corresponding to the target flow rate is used as the target liquid outlet temperature of the liquid cooling unit, and the target cooling capacity of the liquid cooling unit is determined according to the target liquid outlet temperature.

[0156] Exemplarily, according to the technical solution of this embodiment, the preset operating condition parameters of the energy storage system where the liquid cooling unit is located are first set, the outlet temperature of the liquid cooling unit is set to change from the minimum set temperature to the maximum set temperature, and the flow rate of the liquid cooling unit is set to change from the minimum set flow rate to the maximum set flow rate. For example, the set temperatures are 18°C, 22°C and 24°C, and the set flow rates are 4L / min, 5L / min and 6L / min, respectively. Under each parameter group, the battery cells in a single liquid-cooled battery pack are controlled to charge and discharge according to the preset operating condition parameters. Under each parameter group, during the charging and discharging process of the battery cells, the highest temperature of all the battery cells in the liquid-cooled battery pack is obtained, that is, the difference between the maximum sampling temperature and the minimum sampling temperature of all sampling points of the battery cells, to determine whether the temperature parameters of the battery cells during the charging and discharging process meet the temperature control conditions. For example, the first preset temperature is 40°C, and the second preset temperature is 3°C.

[0157] Table 2 is the maximum temperature table of the battery cell corresponding to each parameter group. As shown in Table 2, when the set temperature is 24°C, the maximum temperature of the battery cell is greater than or equal to 40°C, which does not meet the temperature control conditions. When the set flow rate is 4L / min and the set temperature is 22°C, the temperature control conditions are not met.

[0158] Table 2 Maximum cell temperature corresponding to each parameter group

[0159]

[0160] Table 3 shows the difference between the maximum sampling temperature and the minimum sampling temperature of the battery cell corresponding to each parameter group. As shown in Table 3, when the set flow rate is 4 L / min, the difference between the maximum sampling temperature and the minimum sampling temperature is greater than 3°C, and the temperature control condition is not met. When the set flow rate is 5 L / min and the set temperature is 18°C, the temperature control condition is not met.

[0161] Table 3 The difference between the maximum sampling temperature and the minimum sampling temperature of the battery cell corresponding to each parameter group

[0162]

[0163] Furthermore, when the flow rate of liquid cooling unit 110 is 6 L / min, the temperature variation of the battery cells during the charge and discharge process first meets the temperature control limit. Therefore, the upper limit of the flow rate can be determined to be 6 L / min, the upper limit of the liquid outlet temperature can be determined to be 24°C, and the upper limit of the liquid outlet temperature, 22°C, is used as the target liquid outlet temperature. For example, if the thermal management subsystem includes 96 liquid-cooled battery packs, the target flow rate of the coolant in liquid cooling unit 110 is 96 × 6, or 576 L / min.

[0164] Figure 7 : is a curve diagram of the change of the return liquid temperature of the liquid cooling unit during the charging and discharging process of the battery cell corresponding to the flow upper limit and the target liquid outlet temperature provided by the embodiment of the present invention, such as Figure 7 As shown, the horizontal axis is time, the unit is minutes, the vertical axis is temperature, the unit is ℃, curve ① is the outlet temperature of the liquid cooling unit, that is, the target outlet temperature is 22℃, and curve ② is the return temperature of the liquid cooling unit. Figure 7 The maximum return liquid temperature of the liquid cooling unit corresponding to the target liquid outlet temperature can be determined.

[0165] Figure 8 The real-time heat exchange power curve of the liquid cooling plate corresponding to the flow upper limit and the target liquid outlet temperature provided by the embodiment of the present invention is the cooling power demand curve. Figure 8 As shown, the horizontal axis is time and the vertical axis is the heat exchange power P of the liquid cooling plate cp ,according to Figure 8 The maximum heat exchange power of the liquid cooling plate can be determined, that is, the peak heat exchange power of the liquid cooling plate, which is the peak cooling power demand.

[0166] like Figure 8 As shown, the peak heat exchange power of the liquid cooling plate is 431W. The cooling load (cooling capacity margin) of the external environment is determined according to the calculation method of the cooling load (cooling capacity margin) of the external environment. a It is about 1300W, so the minimum target cooling capacity of the liquid cooling unit is 96×431+1300=42676W, which is about 42.7kW. The target flow rate of the coolant of the liquid cooling unit can be set to 576L / min. The cooling capacity of the liquid cooling unit is greater than or equal to 42.7kW, thereby realizing the determination of the parameters of the liquid cooling unit.

[0167] An embodiment of the present invention also provides a parameter determination device for a liquid cooling unit. The liquid cooling unit is applied to a thermal management subsystem in an energy storage system. The liquid cooling unit is connected to one side of a heat exchanger, and the other side of the heat exchanger is connected to at least one liquid-cooled battery pack; the liquid-cooled battery pack includes at least one battery cell. Figure 9 This is a schematic diagram of a device for determining parameters of a liquid cooling unit provided by an embodiment of the present invention, with reference to Figure 9 , the parameter determination device of the liquid cooling unit includes:

[0168] The parameter setting module 210 is used to set the outlet temperature of the liquid cooling unit from a minimum set temperature to a maximum set temperature, and to set the flow rate of the liquid cooling unit from a minimum set flow rate to a maximum set flow rate; wherein any set temperature and any set flow rate form a parameter group;

[0169] The charge and discharge control module 220 is used to control the charge and discharge of the cells in a single liquid-cooled battery pack according to the preset operating parameters under each parameter group;

[0170] A first parameter determination module 230 is configured to determine a lower flow rate limit of the liquid cooling unit and an upper limit of the liquid outlet temperature corresponding to each set flow rate based on the temperature parameters of the battery cells during charging and discharging, and to determine an upper flow rate limit of the liquid cooling unit based on the temperature variation of the battery cells during charging and discharging;

[0171] The second parameter determination module 240 is used to determine the target flow rate of the liquid cooling unit according to the upper flow rate limit and the lower flow rate limit, and determine the target cooling capacity of the liquid cooling unit according to the upper liquid outlet temperature limit.

[0172] The device for determining parameters of a liquid cooling unit provided in an embodiment of the present invention can execute the method for determining parameters of a liquid cooling unit provided in any embodiment of the present invention, and has functional modules and beneficial effects corresponding to the execution method.

[0173] An embodiment of the present invention further provides an electronic device, Figure 10 is a structural diagram of an electronic device provided by an embodiment of the present invention, Figure 10 A schematic diagram of the structure of an electronic device 10 that can be used to implement an embodiment of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or claimed herein.

[0174] like Figure 10 As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., which is communicatively connected to the at least one processor 11. The memory stores a computer program that can be executed by the at least one processor. The processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 into the random access memory (RAM) 13. Various programs and data required for the operation of the electronic device 10 can also be stored in the RAM 13. The processor 11, ROM 12, and RAM 13 are connected to each other via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0175] Multiple components in the electronic device 10 are connected to the I / O interface 15, including an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a magnetic disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices via a computer network such as the Internet and / or various telecommunication networks.

[0176] The processor 11 can be any general-purpose and / or specialized processing component with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various specialized artificial intelligence (AI) computing chips, various processors that run machine learning model algorithms, a digital signal processor (DSP), and any other suitable processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as the method for determining parameters of a liquid cooling unit.

[0177] In some embodiments, the method for determining parameters of a liquid cooling unit can be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the method for determining parameters of the liquid cooling unit described above can be performed. Alternatively, in other embodiments, the processor 11 can be configured to execute the method for determining parameters of the liquid cooling unit in any other appropriate manner (e.g., by means of firmware).

[0178] Various embodiments of the systems and techniques described herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), system-on-chip systems (SOCs), programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments can include being implemented in one or more computer programs that are executable and / or interpreted on a programmable system that includes at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0179] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when the computer program is executed by the processor, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The computer program may be executed entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0180] In the context of the present invention, computer-readable storage media can be tangible media that can contain or store a computer program for use with an instruction execution system, device or equipment or used in combination with an instruction execution system, device or equipment. Computer-readable storage media can include but are not limited to electronic, magnetic, optical, electromagnetic, infrared or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, computer-readable storage media can be machine-readable signal media. More specific examples of machine-readable storage media can include electrical connections based on one or more lines, portable computer disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), optical fibers, portable compact disk read-only memories (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0181] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0182] The systems and techniques described herein can be implemented in a computing system that includes back-end components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes front-end components (e.g., a user computer with a graphical user interface or web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such back-end components, middleware components, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0183] A computing system may include clients and servers. The clients and servers are typically remote from each other and typically interact via a communication network. This client-server relationship arises through computer programs running on the respective computers, creating a client-server relationship. The server may be a cloud server, also known as a cloud computing server or cloud host. This server is a hosting product within the cloud computing service ecosystem that addresses the management difficulties and limited scalability of traditional physical hosting and VPS services.

[0184] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present invention can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved. This is not limited herein.

[0185] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A method for determining parameters of a liquid cooling unit, characterized in that: The liquid cooling unit is applied to the thermal management subsystem of the energy storage system, wherein the liquid cooling unit is connected to one side of a heat exchanger, and the other side of the heat exchanger is connected to at least one liquid-cooled battery pack; The liquid-cooled battery pack includes at least one battery cell; the method includes: Setting the outlet temperature of the liquid cooling unit to change from a minimum set temperature to a maximum set temperature, and setting the flow rate of the liquid cooling unit to change from a minimum set flow rate to a maximum set flow rate; wherein any one of the set temperatures and any one of the set flows form a parameter group; Under each parameter group, controlling the battery cells in a single liquid-cooled battery pack to charge and discharge according to preset operating condition parameters; Determine the lower flow limit of the liquid cooling unit and the upper limit of the liquid outlet temperature corresponding to each set flow rate according to the temperature parameters of the battery cell during charging and discharging, and determine the upper limit of the flow rate of the liquid cooling unit according to the temperature change amplitude of the battery cell during charging and discharging; The target flow rate of the liquid cooling unit is determined according to the flow rate upper limit and the flow rate lower limit, and the target cooling capacity of the liquid cooling unit is determined according to the liquid outlet temperature upper limit.

2. The method according to claim 1, characterized in that Determining the lower flow limit of the liquid cooling unit and the upper limit of the liquid outlet temperature corresponding to each set flow rate according to the temperature parameters of the battery cell during the charging and discharging process, and determining the upper limit of the flow rate of the liquid cooling unit according to the temperature change amplitude of the battery cell during the charging and discharging process, including: The minimum flow rate of the liquid cooling unit corresponding to when the temperature parameter of the battery cell meets the temperature control condition during charging and discharging is used as the lower flow limit of the liquid cooling unit, and the minimum flow rate of the liquid cooling unit corresponding to when the temperature change amplitude of the battery cell reaches the temperature control limit condition during charging and discharging is used as the upper flow limit of the liquid cooling unit; The minimum outlet liquid temperature of the liquid cooling unit corresponding to each set flow rate when the temperature parameter of the battery cell does not meet the temperature control condition during the charging and discharging process is used as the upper limit of the outlet liquid temperature corresponding to each set flow rate.

3. The method according to claim 2, characterized in that The temperature parameters of the battery cell during the charge and discharge process meet the temperature control conditions, including: The maximum temperature of the battery cell during charging and discharging is less than a first preset temperature, and the difference between the maximum sampling temperature and the minimum sampling temperature of all sampling points on the battery cell is less than a second preset temperature; The temperature change of the battery cell during the charge and discharge process reaches the temperature control limit condition, including: At the same set temperature, the difference between the maximum temperature of the battery cell during the charging and discharging process at the current set flow rate and the maximum temperature of the battery cell during the charging and discharging process at the previous set flow rate is less than a third preset temperature; wherein the current set flow rate is greater than the previous set flow rate.

4. The method according to claim 1, wherein Determining a target flow rate of the liquid cooling unit according to the flow rate upper limit and the flow rate lower limit, and determining a target cooling capacity of the liquid cooling unit according to the liquid outlet temperature upper limit, including: multiplying the flow rate upper limit by the number of liquid-cooled battery packs in the thermal management subsystem as the target flow rate of the liquid cooling unit; Any temperature lower than the upper limit of the liquid outlet temperature corresponding to the target flow rate is used as the target liquid outlet temperature of the liquid cooling unit, and the target cooling capacity of the liquid cooling unit is determined according to the target liquid outlet temperature.

5. The method according to claim 4, characterized in that Before determining the target cooling capacity of the liquid cooling unit according to the target liquid outlet temperature, the method further includes: Determining the peak heat exchange power of the liquid cooling plate corresponding to each parameter group when the temperature parameters of the battery cell during charging and discharging meet the temperature control conditions; Determining a target cooling capacity of the liquid cooling unit according to the target liquid outlet temperature includes: The target cooling capacity of the liquid cooling unit is determined according to the target liquid outlet temperature and the peak heat exchange power of the liquid cooling plate.

6. The method according to claim 5, characterized in that When determining that the temperature parameters of the battery cell during the charging and discharging process meet the temperature control conditions, the peak value of the liquid cooling plate heat exchange power corresponding to each parameter group includes: When determining that the temperature parameters of the battery cell during the charge and discharge process meet the temperature control conditions, during the charge and discharge period, the maximum return liquid temperature of the liquid cooling unit corresponding to each of the liquid outlet temperatures; Under each parameter group, calculating the peak temperature difference between the liquid outlet temperature and the maximum liquid return temperature; The product of the specific heat capacity of the coolant in the liquid cooling unit, the temperature difference peak corresponding to each parameter group and the set flow rate is used as the peak heat exchange power of the liquid cooling plate.

7. The method according to claim 5, characterized in that The step of setting any temperature that is less than the upper limit of the liquid outlet temperature corresponding to the target flow rate as the target liquid outlet temperature of the liquid cooling unit includes: The previous set temperature of the upper limit of the liquid outlet temperature corresponding to the upper limit of the flow rate is used as the target liquid outlet temperature; Determining a target cooling capacity of the liquid cooling unit according to the target liquid outlet temperature and the peak heat exchange power of the liquid cooling plate includes: The product of the peak heat exchange power of the liquid cooling plate corresponding to the target liquid outlet temperature and the flow upper limit and the number of liquid-cooled battery packs in the thermal management subsystem is used as the first cooling power; the sum of the first cooling power and the cooling capacity margin is used as the minimum target cooling capacity of the liquid cooling unit.

8. The method according to claim 7, characterized in that Before taking the sum of the first cooling power and the cooling capacity margin as the minimum target cooling capacity of the liquid cooling unit, the method further includes: The cooling capacity margin is determined based on the total heat transfer coefficient of the cabin of the energy storage system where the thermal management subsystem is located, the convection heat transfer coefficient, the thickness of the insulation material of the cabin, the thermal conductivity of the insulation material of the cabin, the ambient temperature difference of the energy storage system, the solar radiation intensity, the surface area of ​​the energy storage system and the shortwave absorption rate of the energy storage system.

9. The method according to claim 1, characterized in that Before setting the outlet temperature of the liquid cooling unit to change gradually from the minimum set temperature to the maximum set temperature, the method further includes: The preset operating condition parameters of the energy storage system where the liquid cooling unit is located are set; wherein the preset operating condition parameters at least include the charge and discharge rate, the number of charge and discharge times, and the time interval between the charging process and the discharging process.

10. A device for determining parameters of a liquid cooling unit, characterized in that: The liquid cooling unit is applied to the thermal management subsystem of the energy storage system, wherein the liquid cooling unit is connected to one side of a heat exchanger, and the other side of the heat exchanger is connected to at least one liquid-cooled battery pack; The liquid-cooled battery pack includes at least one battery cell; the parameter determination device of the liquid cooling unit includes: a parameter setting module, configured to set the outlet temperature of the liquid cooling unit from a minimum set temperature to a maximum set temperature, and to set the flow rate of the liquid cooling unit from a minimum set flow rate to a maximum set flow rate; wherein any one of the set temperatures and any one of the set flows form a parameter group; A charge and discharge control module, configured to control the battery cells in a single liquid-cooled battery pack to charge and discharge according to preset operating parameters under each parameter group; A first parameter determination module is used to determine the lower flow limit of the liquid cooling unit and the upper limit of the liquid outlet temperature corresponding to each set flow rate according to the temperature parameters of the battery cell during charging and discharging, and to determine the upper limit of the flow rate of the liquid cooling unit according to the temperature change amplitude of the battery cell during charging and discharging; The second parameter determination module is used to determine the target flow rate of the liquid cooling unit according to the upper flow rate limit and the lower flow rate limit, and determine the target cooling capacity of the liquid cooling unit according to the upper liquid outlet temperature limit.

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