Temperature control method and device for energy storage equipment

Abstract

The invention discloses a temperature control method and device for energy storage equipment, and relates to the field of temperature control, and the method comprises the steps: determining the target water outlet temperature of a liquid cooling unit according to the charging rate or discharging rate of a battery in the energy storage equipment; the environment temperature of the environment where the energy storage equipment is located is obtained; a current heat dissipation mode is determined based on the difference value between the target water outlet temperature and the environment temperature; and cooling the cooling liquid based on the current heat dissipation mode. The environment temperature can influence the temperature of the battery, meanwhile, the higher the charge-discharge rate of the battery is, the larger the heat productivity of the battery is, the target water outlet temperature determined based on the charge-discharge rate can meet the heat dissipation of the battery, and the difference value between the environment temperature and the target water outlet temperature can decide the working mode suitable for the current working condition. Different heat dissipation powers can be provided by dry cooler heat dissipation, heat exchanger heat dissipation and mixed heat dissipation of dry cooler heat dissipation and heat exchanger heat dissipation, and the problems of energy conservation and insufficient heat dissipation caused by mismatching of the heat dissipation powers and heat dissipation requirements can be avoided.

Description

Technical Field

[0001] The present invention relates to the field of temperature control, and particularly to a temperature control method and device for an energy storage device. Background Art

[0002] A large amount of heat is generated during the charge and discharge processes of energy storage batteries. If the heat cannot be discharged in time, there are safety risks such as fire and explosion due to overheating of the energy storage batteries. Therefore, it is necessary to perform thermal management on the energy storage batteries to ensure the safety and stability of the energy storage batteries. For example, in the face of some customer types with large and rapid fluctuations in electrical load, as the power of the load fluctuates, the temperature of the battery also fluctuates rapidly. Using an air cooler may not be able to provide sufficient heat dissipation for high-power energy storage batteries. And using a heat exchanger for refrigeration causes a certain amount of energy waste for low-power energy storage batteries. Summary of the Invention

[0003] The purpose of the present invention is to provide a temperature control method and device for an energy storage device. The heat dissipation by an air cooler, the heat dissipation by a heat exchanger, and the mixed heat dissipation of the air cooler and the heat exchanger can provide different heat dissipation powers, which can avoid the energy-saving problems and insufficient heat dissipation problems caused by the mismatch between the heat dissipation power and the heat dissipation demand.

[0004] To solve the above technical problems, the present invention provides a temperature control method for an energy storage device. The energy storage device includes a battery and a liquid cooling unit. The liquid cooling system for temperature management of the energy storage device includes a coolant, and the water circuit where the coolant is located is connected to each liquid cooling unit;

[0005] The temperature control method for the energy storage device includes:

[0006] Determine the target outlet temperature of the liquid cooling unit according to the charge rate or discharge rate of the battery in the energy storage device. The heat generation amount of the battery is positively correlated with the charge rate or the discharge rate;

[0007] Obtain the ambient temperature of the environment where the energy storage device is located;

[0008] Determine the current heat dissipation method based on the difference between the target outlet temperature and the ambient temperature. The heat dissipation method includes at least one of heat dissipation by an air cooler, heat dissipation by a heat exchanger, and mixed heat dissipation of the air cooler and the heat exchanger;

[0009] Cool down the coolant based on the current heat dissipation method.

[0010] On the other hand, determining the target outlet temperature of the liquid cooling unit according to the charge rate or discharge rate of the battery in the energy storage device includes:

[0011] Pre-divide the charge rate and the discharge rate into a preset number of levels;

[0012] When the battery is in the charging condition, C rate is the charging rate, and the target outlet temperature is determined according to the level of the charging rate. The expression of the target outlet temperature is ;

[0013] wherein, T cx is the charging reference temperature of the charging rate at the x-th level, β cx is the rate coefficient of the charging rate at the x-th level, C rate is the charging rate or the discharging rate, and x is a non-negative integer;

[0014] When the battery is in the discharging condition, C rate is the discharging rate, and the target outlet temperature is determined according to the level of the discharging rate. The expression of the target outlet temperature is ;

[0015] wherein, T dx is the discharging reference temperature of the discharging rate at the x-th level, β dx is the rate coefficient of the discharging rate at the x-th level.

[0016] On the other hand, the liquid cooling system further includes a first refrigeration circuit, and the first refrigeration circuit includes an air cooler;

[0017] Determining the current heat dissipation method based on the difference between the target outlet temperature and the ambient temperature, including:

[0018] When the difference between the target outlet temperature and the ambient temperature is not less than a first temperature, it is determined that the current heat dissipation method is air cooler heat dissipation;

[0019] Cooling down the coolant based on the current heat dissipation method, including:

[0020] Controlling the water path where the coolant is located to flow through the first refrigeration circuit;

[0021] Controlling the cooling fan of the air cooler to rotate to dissipate heat from the water path where the coolant is located.

[0022] On the other hand, the liquid cooling system further includes a second refrigeration circuit, and the second refrigeration circuit includes a compressor, a condenser and a heat exchanger;

[0023] After controlling the cooling fan of the air cooler to rotate to dissipate heat from the water path where the coolant is located, it further includes:

[0024] When the rotation speed of the cooling fan of the air cooler does not exceed a preset rotation speed, and the difference between the current outlet temperature and the target outlet temperature is not greater than a preset temperature difference, it is determined that the current heat dissipation method is air cooler heat dissipation;

[0025] When the rotation speed of the dry cooler exceeds the preset rotation speed and the difference between the current outlet water temperature and the target outlet water temperature is greater than the preset temperature difference, it is determined that the current heat dissipation method is a mixed heat dissipation of the dry cooler and the heat exchanger;

[0026] Cooling the coolant based on the current heat dissipation method includes:

[0027] Controlling the water circuit where the coolant is located to flow through the heat exchangers in the first refrigeration circuit and the second refrigeration circuit respectively;

[0028] Keeping the cooling fan of the dry cooler rotating to dissipate heat from the water circuit where the coolant of the liquid cooling system is located;

[0029] Controlling the compressor, the condenser and the heat exchanger to work to dissipate heat from the water circuit where the coolant is located.

[0030] On the other hand, the liquid cooling system further includes a first refrigeration circuit and a second refrigeration circuit. The first refrigeration circuit includes a dry cooler, and the second refrigeration circuit includes a compressor, a condenser and a heat exchanger;

[0031] Determining the current heat dissipation method based on the difference between the target outlet water temperature and the ambient temperature includes:

[0032] When the difference between the target outlet water temperature and the ambient temperature is not lower than the second temperature and lower than the first temperature, it is determined that the current heat dissipation method is a mixed heat dissipation of the dry cooler and the heat exchanger, and the first temperature is higher than the second temperature;

[0033] Cooling the coolant based on the current heat dissipation method includes:

[0034] Controlling the water circuit where the coolant is located to flow through the heat exchangers in the first refrigeration circuit and the second refrigeration circuit respectively;

[0035] Controlling the cooling fan of the dry cooler to rotate to dissipate heat from the water circuit where the coolant is located;

[0036] Controlling the compressor, the condenser and the heat exchanger to work to dissipate heat from the water circuit where the coolant is located;

[0037] When the rotation speed of the dry cooler does not exceed the preset rotation speed and the difference between the current outlet water temperature and the target outlet water temperature is not greater than the preset temperature difference, it is determined that the current heat dissipation method is dry cooler heat dissipation.

[0038] On the other hand, after controlling the compressor, the condenser, and the heat exchanger to operate to dissipate heat from the water circuit where the coolant is located, it further includes:

[0039] If the operating frequency of the compressor continuously reaches the first frequency within a preset time, and the difference between the current outlet temperature and the target outlet temperature continuously exceeds the preset temperature difference, determine that the current heat dissipation method is heat dissipation by the heat exchanger;

[0040] Cooling the coolant based on the current heat dissipation method includes:

[0041] Control the water circuit where the coolant is located to flow through the heat exchanger of the second refrigeration circuit;

[0042] Control the compressor, the condenser, and the heat exchanger to operate to dissipate heat from the water circuit where the coolant is located.

[0043] On the other hand, after controlling the compressor, the condenser, and the heat exchanger to operate to dissipate heat from the water circuit where the coolant is located, it further includes:

[0044] If the operating frequency of the compressor does not continuously remain less than the second frequency within a preset time, and the difference between the target outlet temperature and the current outlet temperature does not continuously exceed the preset temperature difference, determine that the current heat dissipation method is hybrid heat dissipation by the air cooler and the heat exchanger;

[0045] If the operating frequency of the compressor continuously remains less than the second frequency within a preset time, and the difference between the target outlet temperature and the current outlet temperature continuously exceeds the preset temperature difference, determine that the current heat dissipation method is heat dissipation by the air cooler, and the second frequency is less than the first frequency;

[0046] Cooling the coolant based on the current heat dissipation method includes:

[0047] Control the water circuit where the coolant is located to flow through the first refrigeration circuit;

[0048] Control the cooling fan of the air cooler to rotate to dissipate heat from the water circuit where the coolant of the liquid cooling system is located;

[0049] Control the compressor, the condenser, and the heat exchanger to stop working.

[0050] On the other hand, the liquid cooling system includes a first refrigeration circuit and a second refrigeration circuit. The first refrigeration circuit includes an air cooler, and the second refrigeration circuit includes a compressor, a condenser, and a heat exchanger;

[0051] Determining the current heat dissipation method based on the difference between the target outlet temperature and the ambient temperature includes:

[0052] When the difference between the target outlet temperature and the ambient temperature is lower than the second temperature, determine that the current heat dissipation method is heat exchanger heat dissipation;

[0053] Cool down the coolant based on the current heat dissipation method, including:

[0054] Control the water path where the coolant is located to flow through the heat exchanger of the second refrigeration circuit;

[0055] Control the compressor, the condenser and the heat exchanger to work to dissipate heat from the water path where the coolant of the liquid cooling system is located.

[0056] On the other hand, after controlling the compressor, the condenser and the heat exchanger to work to dissipate heat from the water path where the coolant of the liquid cooling system is located, it further includes:

[0057] If the operating frequency of the compressor does not continuously decrease below the third frequency within a preset time, and the difference between the target outlet temperature and the current outlet temperature does not continuously exceed the preset temperature difference, determine that the current heat dissipation method is heat exchanger heat dissipation;

[0058] If the operating frequency of the compressor continuously decreases below the third frequency within a preset time, and the difference between the target outlet temperature and the current outlet temperature continuously exceeds the preset temperature difference, determine that the current heat dissipation method is a mixed heat dissipation of dry cooler heat dissipation and heat exchanger heat dissipation;

[0059] Cool down the coolant based on the current heat dissipation method, including:

[0060] Control the water path where the coolant is located to flow through the heat exchangers of the first refrigeration circuit and the second refrigeration circuit respectively;

[0061] Control the cooling fan of the dry cooler to rotate to dissipate heat from the water path where the coolant is located;

[0062] Keep controlling the compressor, the condenser and the heat exchanger to work to dissipate heat from the water path where the coolant is located.

[0063] To solve the above technical problems, the present invention also provides a temperature control device for an energy storage device, including:

[0064] A memory for storing a computer program;

[0065] A processor for implementing the steps of the above-mentioned temperature control method for an energy storage device when executing the computer program.

[0066] The present application provides a temperature control method and device for an energy storage device, relating to the field of temperature control. The method includes determining the target outlet temperature of the liquid cooling unit according to the charging rate or discharging rate of the battery in the energy storage device; obtaining the ambient temperature of the environment where the energy storage device is located; determining the current heat dissipation method based on the difference between the target outlet temperature and the ambient temperature; and cooling the coolant based on the current heat dissipation method. The ambient temperature affects the temperature of the battery, and at the same time, the higher the charge-discharge rate of the battery, the greater the heat generated by the battery. The target outlet temperature determined based on the charge-discharge rate can meet the heat dissipation requirements of the battery. The difference between the ambient temperature and the target outlet temperature can determine the working mode suitable for the current working condition. Dry cooler heat dissipation, heat exchanger heat dissipation, and hybrid heat dissipation of dry cooler and heat exchanger can provide different heat dissipation powers, which can avoid the energy-saving problems and insufficient heat dissipation problems caused by the mismatch between the heat dissipation power and the heat dissipation demand. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required in the prior art and the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0068] Figure 1 It is a flowchart of a temperature control method for an energy storage device provided by the present invention;

[0069] Figure 2 It is a flowchart of another temperature control method for an energy storage device provided by the present invention;

[0070] Figure 3 It is a schematic diagram of dry cooler heat dissipation provided by the present invention;

[0071] Figure 4 It is a schematic diagram of hybrid heat dissipation of dry cooler and heat exchanger provided by the present invention;

[0072] Figure 5 It is a schematic diagram of heat exchanger heat dissipation provided by the present invention;

[0073] Figure 6 It is a schematic structural diagram of a temperature control device for an energy storage device provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0074] The core of the present invention is to provide a temperature control method and device for an energy storage device. Dry cooler heat dissipation, heat exchanger heat dissipation, and hybrid heat dissipation of dry cooler and heat exchanger can provide different heat dissipation powers, which can avoid the energy-saving problems and insufficient heat dissipation problems caused by the mismatch between the heat dissipation power and the heat dissipation demand.

[0075] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0076] Figure 1 The figure is a flowchart of a temperature control method for an energy storage device provided by the present invention. The temperature control method for the energy storage device, the energy storage device includes a battery and a liquid cooling unit, and the liquid cooling system for temperature management of the energy storage device includes a coolant, and the water circuit where the coolant is located is connected to each liquid cooling unit;

[0077] The temperature control method for the energy storage device includes:

[0078] S11: Determine the target outlet temperature of the liquid cooling unit according to the charge rate or discharge rate of the battery in the energy storage device. The heat generation of the battery is positively correlated with the charge rate or discharge rate;

[0079] S12: Obtain the ambient temperature of the environment where the energy storage device is located;

[0080] S13: Determine the current heat dissipation method based on the difference between the target outlet temperature and the ambient temperature. The heat dissipation methods include at least one of dry cooler heat dissipation, heat exchanger heat dissipation, and mixed heat dissipation of dry cooler heat dissipation and heat exchanger heat dissipation;

[0081] S14: Cool down the coolant based on the current heat dissipation method.

[0082] The energy storage device includes a battery module, and the battery module includes a battery and a liquid cooling unit. The liquid cooling system can be used for thermal management of the battery module of the energy storage device, and the water circuit of the liquid cooling system is connected to the liquid cooling units of each battery module. The water cooling circuit has two circuits, namely the first refrigeration circuit and the second refrigeration circuit. The first refrigeration circuit includes a dry cooler circuit and dissipates heat through the fan of the dry cooler and natural wind. The second refrigeration circuit dissipates heat through the heat exchanger and the fluorine system. The two circuits are controlled by two three-way valves and can operate the first refrigeration circuit alone, or the second refrigeration circuit alone, or both circuits can operate simultaneously. When the second refrigeration circuit operates, the fluorine system circuit will be enabled simultaneously. The fluorine system has a variable frequency function for refrigeration power and can dissipate heat from the coolant in the heat exchanger.

[0083] Based on the temperature of the battery, the heat dissipation method is adjusted in real time. The temperature of the battery module fluctuates within a certain range, and the highest safe temperature is set. The battery temperature is related to the ambient temperature and is also positively correlated with the charge and discharge power of the energy storage system battery.

[0084] It can be understood that the heat dissipation capacity of the dry cooler is lower than that of the heat exchanger. The difference between the target outlet temperature and the ambient temperature can characterize the power that needs to be provided by the current heat dissipation method. For example, if a relatively low power needs to be provided currently, then heat dissipation by the dry cooler can be adopted. If the heat dissipation by the dry cooler can no longer meet the heat dissipation requirements, then the heat exchanger needs to be added for heat dissipation, and the two heat dissipation methods are carried out simultaneously. If the hybrid heat dissipation method still cannot meet the heat dissipation requirements, then the dry cooler does not need to participate in heat dissipation, and only the heat exchanger is relied on for heat dissipation.

[0085] The coolant serves as the inlet at the water pump and passes through the liquid cooling unit of the energy storage system. If there are multiple batteries in the energy storage system, then there will be multiple liquid cooling units. Furthermore, the coolant will flow through each liquid cooling unit respectively, and then dissipate heat for each battery. After the coolant flows out of the energy storage system, it needs to be cooled down before returning to the water pump. Therefore, during the process of heat dissipation and cooling, it can be selected to flow through the circuit where the dry cooler is located for heat dissipation and cooling, or it can be selected to flow through the circuit where the heat exchanger is located for heat dissipation and cooling. Similarly, it can also be selected to flow through the circuit where the dry cooler is located and the circuit where the heat exchanger is located simultaneously to achieve hybrid heat dissipation and cooling.

[0086] The present application provides a temperature control method and device for an energy storage device, relating to the field of temperature control, including determining the target outlet temperature of the liquid cooling unit according to the charging rate or discharging rate of the battery in the energy storage device; obtaining the ambient temperature of the environment where the energy storage device is located; determining the current heat dissipation method based on the difference between the target outlet temperature and the ambient temperature; and cooling down the coolant based on the current heat dissipation method. The ambient temperature affects the temperature of the battery. At the same time, the higher the charge-discharge rate of the battery, the greater the heat generation of the battery. The target outlet temperature determined based on the charge-discharge rate can meet the heat dissipation of the battery, and the difference between the ambient temperature and the target outlet temperature can determine the working mode suitable for the current working condition. Heat dissipation by the dry cooler, heat dissipation by the heat exchanger, and hybrid heat dissipation by the dry cooler and the heat exchanger can provide different heat dissipation powers, which can avoid the energy-saving problems and insufficient heat dissipation problems caused by the mismatch between the heat dissipation power and the heat dissipation requirements.

[0087] Based on the above embodiments:

[0088] In some embodiments, determining the target outlet temperature of the liquid cooling unit according to the charging rate or discharging rate of the battery in the energy storage device includes:

[0089] Pre-divide the charging rate and the discharging rate into a preset number of levels;

[0090] When the battery is in the charging working condition, C rate is the charging rate, and the target outlet temperature is determined according to the level of the charging rate. The expression of the target outlet temperature is ;

[0091] Among them, T cx is the charging reference temperature of the charging rate at the x-th level, and β cx is the rate coefficient of the charging rate at the x-th level, C rate is the charging rate or discharging rate, and x is a non-negative integer;

[0092] When the battery is in the discharging condition, C rate is the discharging rate, and the target outlet temperature is determined according to the level of the discharging rate. The expression of the target outlet temperature is ;

[0093] Among them, T dx is the discharging reference temperature of the discharging rate at the x-th level, and β dx is the rate coefficient of the discharging rate at the x-th level.

[0094] Based on the battery module temperature, the operation mode of the temperature control system is adjusted in real time. The temperature of the battery module fluctuates within a certain range of ±3 degrees, and the highest safe temperature is set. The battery temperature is related to the ambient temperature and is positively correlated with the charge and discharge power of the energy storage system battery.

[0095] According to the current system charging rate or discharging rate C rate , the system will obtain the target outlet temperature T set according to the following table. Table 1 is the corresponding relationship table between the working condition and the target liquid temperature.

[0096] Table 1 Corresponding relationship table between working condition and target liquid temperature

[0097]

[0098] The charging condition is divided into x levels. The first level is that the charging rate is between 0 and α1C, the second level is that the charging rate is between α1C and α2C, and so on. The last interval is between α x-1 C and α x C. The corresponding target outlet temperature of the first interval is T C1 -β C1 ×C rate , T c1 is the charging reference temperature of the charging rate at the 1st level, T c2 is the charging reference temperature of the charging rate at the 2nd level,..., T cx is the charging reference temperature of the charging rate at the x-th level, β c1 is the rate coefficient of the charging rate at the 1st level, β c2 is the rate coefficient of the charging rate at the 2nd level,..., β cx is the rate coefficient of the charging rate at the x-th level. T d1The discharge reference temperature of the first level discharge rate, T d2 is the discharge reference temperature of the second level discharge rate, ..., T dx is the discharge reference temperature of the x-th level of discharge rate, β d1 is the rate coefficient of the first level of discharge rate, β d2 is the rate coefficient of the second level discharge rate, ..., β dx is the rate coefficient of the discharge rate at the xth level.

[0099] The discharge condition is also divided into x levels, using the same method as above.

[0100] It should be noted that the capacity coefficients α1, α2, …α x It needs to be set according to the actual situation. C is the abbreviation of Capacity, which means the discharge or charge rate of the battery relative to its total capacity. 1C means the current at which the battery is fully discharged (or charged) in 1 hour. For example: a battery with a nominal capacity of 3000mAh (3Ah): 1C discharge = 3000mA (or 3A) current, which is fully discharged in 1 hour. 0.5C discharge = 1500mA (1.5A), which takes 2 hours to fully discharge. 2C discharge = 6000mA (6A), which takes only 0.5 hour (30 minutes) to fully discharge.

[0101] Figure 2 A flow chart of another temperature control method for energy storage equipment provided by the present invention;

[0102] Figure 3 A schematic diagram of heat dissipation of a dry cooler provided by the present invention;

[0103] In some embodiments, the liquid cooling system further comprises a first refrigeration circuit, the first refrigeration circuit comprising a dry cooler;

[0104] The current cooling method is determined based on the difference between the target water outlet temperature and the ambient temperature, including:

[0105] When the difference between the target water outlet temperature and the ambient temperature is not less than the first temperature, determining that the current heat dissipation method is dry cooler heat dissipation;

[0106] Cooling the coolant is based on the current heat dissipation methods, including:

[0107] Control the water path where the coolant is located to flow through the first refrigeration circuit;

[0108] The cooling fan of the dry cooler is controlled to rotate to dissipate heat for the water path where the coolant is located.

[0109] like Figure 2 As shown, when the energy storage device is just started, if the ambient temperature T env Lower than the target water outlet temperature Tset When the temperature reaches above the first temperature T1, only the first refrigeration circuit is enabled.

[0110] It should be noted that when this application describes the difference value, it is default that the previous value minus the latter value, that is, the difference between the target outlet temperature and the ambient temperature is the value obtained by target outlet temperature - ambient temperature.

[0111] As Figure 3 shown, this application connects the first refrigeration circuit and the water circuit through a three-way valve. The cooling fan of the dry cooler in the first refrigeration circuit can generally be a fan. Open Figure 3 the three-way valve 1 and the three-way valve 2 in

[0112] set so that the coolant passes through the dry cooler. Since the fan rotates towards the coolant, it can take away part of the heat of the coolant, thereby realizing the cooling of the coolant. The fan can be one or more. For one fan, the rotation power of the fan can be adjusted according to the battery temperature to further reduce energy consumption. Multiple fans can also be configured, and the number of fans in operation can be adjusted according to the battery temperature, so as to adjust the operation frequency according to the refrigeration demand.

[0113] Figure 4 FIG. is a schematic diagram of hybrid heat dissipation of dry cooler heat dissipation and heat exchanger heat dissipation provided by the present invention;

[0114] In some embodiments, the liquid cooling system further includes a second refrigeration circuit, and the second refrigeration circuit includes a compressor, a condenser and a heat exchanger;

[0115] After controlling the cooling fan of the dry cooler to rotate to dissipate heat for the water circuit where the coolant is located, it further includes:

[0116] When the rotation speed of the cooling fan of the dry cooler does not exceed the preset rotation speed n1, and the difference between the current outlet temperature and the target outlet temperature is not greater than the preset temperature difference, it is determined that the current heat dissipation method is dry cooler heat dissipation;

[0117] When the rotation speed of the dry cooler exceeds the preset rotation speed n1, and the difference between the current outlet temperature and the target outlet temperature is greater than the preset temperature difference, it is determined that the current heat dissipation method is hybrid heat dissipation of dry cooler heat dissipation and heat exchanger heat dissipation;

[0118] Based on the current heat dissipation method to cool the coolant, it includes:

[0119] Controlling the water circuit where the coolant is located to flow through the heat exchangers in the first refrigeration circuit and the second refrigeration circuit respectively;

[0120] Keep the cooling fan of the control dry cooler rotating to dissipate heat from the water circuit where the coolant of the liquid cooling system is located;

[0121] Control the compressor, condenser and heat exchanger to work to dissipate heat from the water circuit where the coolant is located.

[0122] As Figure 4 shown, the condenser, compressor and heat exchanger are core components in a refrigeration system (such as air conditioners, refrigerators) or a thermal management system. They work together to achieve heat transfer and energy conversion. The following is the working process of the three and their cooperation mechanism in the refrigeration system:

[0123] The compressor compresses the low-temperature and low-pressure refrigerant gas into a high-temperature and high-pressure gas, providing power for the refrigeration cycle. The low-temperature and low-pressure refrigerant gas after evaporation is inhaled, and the gas is compressed through mechanical movement, reducing its volume, increasing its pressure, and significantly rising its temperature. The high-temperature and high-pressure refrigerant gas is transported to the condenser to enter the next cycle link.

[0124] The condenser cools the high-temperature and high-pressure refrigerant gas into a medium-temperature and high-pressure liquid, while releasing heat to the external environment. The high-temperature and high-pressure refrigerant gas from the compressor enters the condenser. The refrigerant gas exchanges heat with the external cooling medium (such as air): the fan forces air to flow to take away the heat of the refrigerant. The refrigerant gas gradually condenses into a liquid due to the temperature drop, and the pressure remains at a relatively high level. The condensed medium-temperature and high-pressure refrigerant liquid enters the next link. The heat exchanger evaporates the low-temperature and low-pressure refrigerant liquid into a gas, absorbing heat from the outside. The medium-temperature and high-pressure refrigerant liquid from the condenser passes through the expansion valve and throttles, with the pressure dropping suddenly and the temperature decreasing significantly, becoming a low-temperature and low-pressure gas-liquid mixture. The low-temperature refrigerant enters the evaporator (coil structure, with a fan outside), and exchanges heat with the outside (such as indoor air): the liquid component in the refrigerant absorbs heat and evaporates into a gas, reducing the temperature of the surrounding environment. Air or water is used as a heat source to transfer heat to the refrigerant. The evaporated low-temperature and low-pressure refrigerant gas is inhaled by the compressor to start a new cycle.

[0125] After dissipating heat from the coolant through the dry cooler, it is also necessary to monitor the current outlet temperature T LO . It should be noted that the outlet temperature can be achieved by a temperature detector set inside the pipe where the three-way valve is located. The specific temperature detection method is not limited too much in this application.

[0126] When the fan reaches a speed above n1 and the current outlet temperature T LO > the target outlet temperature, the target outlet temperature T setThe preset temperature difference T0 lasts for x minutes, indicating that the current fan speed can no longer provide good cooling function. Therefore, the second refrigeration circuit is started and the first refrigeration circuit is maintained. At this time, the fluorine system operates at a low power state to supplement the insufficient cooling capacity of the first refrigeration circuit.

[0127] If the above situation does not occur, the current heat dissipation method can be maintained.

[0128] In actual data, the preset temperature difference T0 can be set to 2 - 3°C.

[0129] As the system operates, based on the current outlet temperature T LO Real-time monitoring is carried out, and the operating frequency of the fluorine system responds in real-time according to the temperature. As the temperature rises, the power of the fluorine system increases.

[0130] It should also be noted that the three-way valve can be replaced by 2 single-channel valves, or valves with different control methods. This application is only illustrated by taking the three-way valve as an example.

[0131] In some embodiments, the liquid cooling system further includes a first refrigeration circuit and a second refrigeration circuit. The first refrigeration circuit includes an air-cooled condenser, and the second refrigeration circuit includes a compressor, a condenser, and a heat exchanger;

[0132] Determining the current heat dissipation method based on the difference between the target outlet temperature and the ambient temperature includes:

[0133] When the difference between the target outlet temperature and the ambient temperature is not lower than the second temperature and lower than the first temperature, it is determined that the current heat dissipation method is a mixed heat dissipation of air-cooled condenser heat dissipation and heat exchanger heat dissipation, and the first temperature is higher than the second temperature;

[0134] Cooling the coolant based on the current heat dissipation method includes:

[0135] Controlling the water path where the coolant is located to flow through the heat exchangers in the first refrigeration circuit and the second refrigeration circuit respectively;

[0136] Controlling the rotation of the cooling fan of the air-cooled condenser to dissipate heat for the water path where the coolant is located;

[0137] Controlling the compressor, condenser, and heat exchanger to work to dissipate heat for the water path where the coolant is located.

[0138] If the ambient temperature is between the first temperature T1 and the second temperature T2, the first temperature T1 can generally be set to 8 - 10°C, and the second temperature T2 can generally be set to 3 - 5°C. The current ambient temperature can no longer rely on the air-cooled condenser to achieve heat dissipation, so the first refrigeration circuit and the second refrigeration circuit need to work simultaneously for heat dissipation.

[0139] It should be noted that when only the first refrigeration circuit is used, the coolant flows through the three-way valve 1, the dry cooler and the three-way valve 2 and then returns to the water pump. When only the second refrigeration circuit is used, the coolant flows through the three-way valve 1, the heat exchanger and the three-way valve 2 and then returns to the water pump. If mixed heat dissipation is adopted, the coolant flows through the first refrigeration circuit and the second refrigeration circuit respectively.

[0140] In some embodiments, after controlling the compressor, the condenser and the heat exchanger to operate so as to dissipate heat from the water circuit where the coolant is located, it further includes:

[0141] If the operating frequency of the compressor continuously reaches the first frequency within a preset time, and the difference between the current outlet temperature and the target outlet temperature continuously exceeds the preset temperature difference, it is determined that the current heat dissipation method is heat dissipation by the heat exchanger;

[0142] Based on the current heat dissipation method to cool down the coolant, it includes:

[0143] Controlling the water circuit where the coolant is located to flow through the heat exchanger of the second refrigeration circuit;

[0144] Controlling the compressor, the condenser and the heat exchanger to operate so as to dissipate heat from the water circuit where the coolant is located.

[0145] If the compressor frequency reaches above the first frequency f1 and the current outlet temperature T LO > the target outlet temperature T set + the preset temperature difference T0 for x minutes continuously. The direction is controlled by the three-way valve, and the first refrigeration circuit is closed. Keep the second refrigeration circuit running. Ensure that the fluorine system operates at the highest energy efficiency point.

[0146] If the current frequency of the compressor is already very high, but the temperature is still not ideal enough, it means that the dry cooler cannot undertake the heat dissipation task. At this time, all the coolant needs to rely on the heat exchanger for heat dissipation. Considering that the condenser and the dry cooler use the same set of cooling fans, the cooling fans need to work under all three working conditions.

[0147] The first frequency f1 can be set to 40 Hz, as a relatively high frequency.

[0148] In some embodiments, after controlling the compressor, the condenser and the heat exchanger to operate so as to dissipate heat from the water circuit where the coolant is located, it further includes:

[0149] If the operating frequency of the compressor does not continuously remain less than the second frequency within a preset time, and the difference between the target outlet temperature and the current outlet temperature does not continuously exceed the preset temperature difference, it is determined that the current heat dissipation method is a mixed heat dissipation of the dry cooler and the heat exchanger;

[0150] If the operating frequency of the compressor continuously remains less than the second frequency within a preset time, and the difference between the target outlet temperature and the current outlet temperature continuously remains greater than the preset temperature difference, determine that the current heat dissipation method is dry cooler heat dissipation, and the second frequency is less than the first frequency;

[0151] Based on the current heat dissipation method being to cool down with coolant, it includes:

[0152] Control the water path where the coolant is located to flow through the first refrigeration circuit;

[0153] Control the cooling fan of the dry cooler to rotate to dissipate heat for the water path where the coolant of the liquid cooling system is located;

[0154] Control the compressor, condenser, and heat exchanger to stop working.

[0155] Refer to Figure 2 As shown, if the compressor frequency reaches below the second frequency f2 and the current outlet temperature T LO <the target outlet temperature T set - the preset temperature difference T0 lasts for x minutes, start the first refrigeration circuit, and keep the second refrigeration circuit and the fluorine system running.

[0156] The second frequency f2 can be set to 25Hz, as a relatively low frequency. When the frequency of the compressor is relatively low, it proves that only using the dry cooler for heat dissipation can also meet the heat dissipation requirements at this time. So at this time, close the second refrigeration circuit and use the first refrigeration circuit to work independently to meet the energy-saving requirements.

[0157] If the above situation does not occur, just keep the current heat dissipation method.

[0158] Figure 5 It is a schematic diagram of heat dissipation of a heat exchanger provided by the present invention;

[0159] In some embodiments, the liquid cooling system includes a first refrigeration circuit and a second refrigeration circuit. The first refrigeration circuit includes a dry cooler, and the second refrigeration circuit includes a compressor, a condenser, and a heat exchanger;

[0160] Based on the difference between the target outlet temperature and the ambient temperature to determine the current heat dissipation method, it includes:

[0161] When the difference between the target outlet temperature and the ambient temperature is lower than the second temperature, determine that the current heat dissipation method is heat dissipation by the heat exchanger;

[0162] Based on the current heat dissipation method being to cool down with coolant, it includes:

[0163] Control the water path where the coolant is located to flow through the heat exchanger of the second refrigeration circuit;

[0164] Control the compressor, condenser and heat exchanger to operate so as to dissipate heat from the water circuit where the coolant of the liquid cooling system is located.

[0165] Refer to Figure 5 As shown, when the difference between the ambient temperature and the target outlet temperature is small, the dry cooler cannot achieve the refrigeration effect, and it is necessary to completely use the heat exchanger for refrigeration. At this time, only control the water circuit to flow through the second refrigeration circuit. The dry cooler does not work.

[0166] In some embodiments, after controlling the compressor, condenser and heat exchanger to operate so as to dissipate heat from the water circuit where the coolant of the liquid cooling system is located, it further includes:

[0167] If the operating frequency of the compressor has not been continuously less than the third frequency within the preset time, and the difference between the target outlet temperature and the current outlet temperature has not been continuously greater than the preset temperature difference, determine that the current heat dissipation method is heat exchanger heat dissipation;

[0168] If the operating frequency of the compressor is continuously less than the third frequency f3 within the preset time, and the difference between the target outlet temperature and the current outlet temperature is continuously greater than the preset temperature difference, determine that the current heat dissipation method is a mixed heat dissipation of the dry cooler and the heat exchanger;

[0169] Cool down the coolant based on the current heat dissipation method, including:

[0170] Control the water circuit where the coolant is located to flow through the heat exchangers of the first refrigeration circuit and the second refrigeration circuit respectively;

[0171] Control the cooling fan of the dry cooler to rotate so as to dissipate heat from the water circuit where the coolant is located;

[0172] Keep controlling the compressor, condenser and heat exchanger to operate so as to dissipate heat from the water circuit where the coolant is located.

[0173] If the operating frequency of the compressor is in a relatively small state, in order to achieve energy saving, a part of the refrigeration task can be assigned to the dry cooler of the first refrigeration circuit. It can not only meet the refrigeration requirements but also save energy. If the above situation does not occur, just keep the current heat dissipation method.

[0174] Figure 6 The structural schematic diagram of a temperature control device for an energy storage device provided by the present invention. The temperature control device of the energy storage device includes:

[0175] A memory 61 for storing a computer program;

[0176] A processor 62 for implementing the steps of the above-mentioned temperature control method of the energy storage device when executing the computer program.

[0177] For the introduction of the temperature control device of the energy storage device provided in this application, please refer to the above-mentioned embodiments and will not be elaborated here.

[0178] It should also be noted that in this specification, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the said element.

[0179] Those skilled in the art can further realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, computer software or a combination of the two. To clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described according to functions in the above description. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0180] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A temperature control method for an energy storage device, characterized in that, The energy storage device includes a battery and a liquid cooling unit. The liquid cooling system for temperature management of the energy storage device includes a coolant, and the water circuit where the coolant is located is connected to each liquid cooling unit; The temperature control method of the energy storage device includes: Determine the target outlet temperature of the liquid cooling unit according to the charge rate or discharge rate of the battery in the energy storage device. The heat generation of the battery is positively correlated with the charge rate or the discharge rate; Obtain the ambient temperature of the environment where the energy storage device is located; Determine the current heat dissipation method based on the difference between the target outlet temperature and the ambient temperature. The heat dissipation method includes at least one of dry cooler heat dissipation, heat exchanger heat dissipation, and mixed heat dissipation of dry cooler heat dissipation and heat exchanger heat dissipation; Cool down the coolant based on the current heat dissipation method.

2. The temperature control method of the energy storage device according to claim 1, characterized in that, Determine the target outlet temperature of the liquid cooling unit according to the charge rate or discharge rate of the battery in the energy storage device, including: Pre-divide the charge rate and the discharge rate into a preset number of levels; When the battery is in the charging condition, C rate is the charging rate, and the target outlet temperature is determined according to the level of the charging rate. The expression of the target outlet temperature is ; Among them, T cx is the charging reference temperature of the charging rate at the x-th level, and β cx is the rate coefficient of the charging rate at the x-th level, where x is a non-negative integer; When the battery is in a discharge condition, C rate is the discharge rate, and the target outlet temperature is determined according to the level of the discharge rate. The expression for the target outlet temperature is ; Among them, T dx is the discharge reference temperature at the discharge rate of the x-th level, and β dx is the rate coefficient at the discharge rate of the x-th level.

3. The temperature control method of the energy storage device according to claim 1 or 2, characterized in that, The liquid cooling system further includes a first refrigeration circuit, and the first refrigeration circuit includes a dry cooler; Determine the current heat dissipation method based on the difference between the target outlet temperature and the ambient temperature, including: When the difference between the target outlet temperature and the ambient temperature is not less than a first temperature, determine that the current heat dissipation method is dry cooler heat dissipation; Cool down the coolant based on the current heat dissipation method, including: Control the water circuit where the coolant is located to flow through the first refrigeration circuit; Control the cooling fan of the dry cooler to rotate to dissipate heat from the water circuit where the coolant is located.

4. The temperature control method of the energy storage device according to claim 3, characterized in that, The liquid cooling system further includes a second refrigeration circuit, and the second refrigeration circuit includes a compressor, a condenser, and a heat exchanger; After controlling the cooling fan of the dry cooler to rotate to dissipate heat from the water circuit where the coolant is located, further include: When the rotation speed of the cooling fan of the dry cooler does not exceed the preset rotation speed, and the difference between the current outlet temperature and the target outlet temperature is not greater than the preset temperature difference, then determine that the current heat dissipation method is dry cooler heat dissipation; When the rotation speed of the cooling fan of the dry cooler exceeds the preset rotation speed, and the difference between the current outlet temperature and the target outlet temperature is greater than the preset temperature difference, determine that the current heat dissipation method is mixed heat dissipation of dry cooler heat dissipation and heat exchanger heat dissipation; Cool down the coolant based on the current heat dissipation method, including: Control the water circuit where the coolant is located to flow through the heat exchanger in the first refrigeration circuit and the second refrigeration circuit respectively; Keep controlling the cooling fan of the dry cooler to rotate to dissipate heat from the water circuit where the coolant of the liquid cooling system is located; Control the compressor, the condenser, and the heat exchanger to work to dissipate heat from the water circuit where the coolant is located.

5. The temperature control method of the energy storage device according to claim 1 or 2, characterized in that, The liquid cooling system further includes a first refrigeration circuit and a second refrigeration circuit. The first refrigeration circuit includes a dry cooler, and the second refrigeration circuit includes a compressor, a condenser, and a heat exchanger; Determine the current heat dissipation method based on the difference between the target outlet temperature and the ambient temperature, including: When the difference between the target outlet temperature and the ambient temperature is not lower than the second temperature and lower than the first temperature, determine that the current heat dissipation method is a combined heat dissipation of an air cooler and a heat exchanger, where the first temperature is higher than the second temperature; Cool down the coolant based on the current heat dissipation method, including: Control the water circuit where the coolant is located to flow through the heat exchanger in the first refrigeration circuit and the second refrigeration circuit respectively; Control the cooling fan of the air cooler to rotate to dissipate heat from the water circuit where the coolant is located; Control the compressor, the condenser, and the heat exchanger to operate to dissipate heat from the water circuit where the coolant is located.

6. The temperature control method of the energy storage device according to claim 5, characterized in that, After controlling the compressor, the condenser, and the heat exchanger to operate to dissipate heat from the water circuit where the coolant is located, it further includes: If the operating frequency of the compressor continuously reaches the first frequency within a preset time, and the difference between the current outlet temperature and the target outlet temperature continuously exceeds the preset temperature difference, determine that the current heat dissipation method is heat dissipation by the heat exchanger; Cool down the coolant based on the current heat dissipation method, including: Control the water circuit where the coolant is located to flow through the heat exchanger in the second refrigeration circuit; Control the compressor, the condenser, and the heat exchanger to operate to dissipate heat from the water circuit where the coolant is located.

7. The temperature control method of the energy storage device according to claim 6, characterized in that, After controlling the compressor, the condenser, and the heat exchanger to operate to dissipate heat from the water circuit where the coolant is located, it further includes: If the operating frequency of the compressor does not continuously fall below the second frequency within the preset time, and the difference between the target outlet temperature and the current outlet temperature does not continuously exceed the preset temperature difference, determine that the current heat dissipation method is a combined heat dissipation of an air cooler and a heat exchanger; If the operating frequency of the compressor continuously falls below the second frequency within the preset time, and the difference between the target outlet temperature and the current outlet temperature continuously exceeds the preset temperature difference, determine that the current heat dissipation method is heat dissipation by the air cooler, where the second frequency is lower than the first frequency; Cool down the coolant based on the current heat dissipation method, including: Control the water circuit where the coolant is located to flow through the first refrigeration circuit; Control the cooling fan of the air cooler to rotate to dissipate heat from the water circuit where the coolant of the liquid cooling system is located; Control the compressor, the condenser, and the heat exchanger to stop operating.

8. The temperature control method of the energy storage device according to claim 1 or 2, characterized in that, The liquid cooling system includes a first refrigeration circuit and a second refrigeration circuit. The first refrigeration circuit includes an air cooler, and the second refrigeration circuit includes a compressor, a condenser, and a heat exchanger; Determine the current heat dissipation method based on the difference between the target outlet temperature and the ambient temperature, including: When the difference between the target outlet temperature and the ambient temperature is lower than the second temperature, determine that the current heat dissipation method is heat dissipation by the heat exchanger; Cool down the coolant based on the current heat dissipation method, including: Control the water circuit where the coolant is located to flow through the heat exchanger in the second refrigeration circuit; Control the compressor, the condenser, and the heat exchanger to operate to dissipate heat from the water circuit where the coolant of the liquid cooling system is located.

9. The temperature control method of the energy storage device according to claim 8, characterized in that, After controlling the compressor, the condenser, and the heat exchanger to operate to dissipate heat from the water circuit where the coolant of the liquid cooling system is located, it further includes: If the operating frequency of the compressor does not continuously remain less than a third frequency within a preset time, and the difference between the target outlet temperature and the current outlet temperature does not continuously remain greater than a preset temperature difference, determine that the current heat dissipation method is heat dissipation by the heat exchanger; If the operating frequency of the compressor continuously remains less than the third frequency within a preset time, and the difference between the target outlet temperature and the current outlet temperature continuously remains greater than the preset temperature difference, determine that the current heat dissipation method is hybrid heat dissipation by the air cooler and the heat exchanger; Cooling the coolant based on the current heat dissipation method includes: Controlling the water circuit where the coolant is located to flow through the heat exchangers of the first refrigeration circuit and the second refrigeration circuit respectively; Controlling the cooling fan of the air cooler to rotate to dissipate heat from the water circuit where the coolant is located; Maintaining the control of the compressor, the condenser, and the heat exchanger to operate to dissipate heat from the water circuit where the coolant is located.

10. A temperature control device for an energy storage device, characterized in that, It includes: A memory for storing a computer program; A processor for implementing the steps of the temperature control method of the energy storage device according to any one of claims 1 to 9 when executing the computer program.

Images