Liquid-cooling heat management system and energy storage cabinet

Abstract

The invention provides a liquid cooling heat management system and an energy storage cabinet, and belongs to the technical field of liquid cooling heat dissipation. The liquid cooling heat management system comprises a plurality of compressors, a condenser, a plurality of throttle valves, an evaporator, a liquid cooling plate, a radiator and a plurality of fans; each compressor is connected between one input end of the condenser and one output end of the evaporator through a pipeline, and each throttle valve is connected between one output end of the condenser and one input end of the evaporator through a pipeline; a pipeline connected with the liquid cooling plate penetrates through the evaporator, the liquid cooling plate is used for being in contact with the battery, a pipeline connected with the radiator penetrates through the condenser, and the multiple fans are arranged at the radiator; a controller of the liquid cooling heat management system is used for adjusting the number and the rotating speed of the running compressors in the multiple compressors and adjusting the number and the opening degree of the opened throttling valves in the multiple throttling valves according to the temperature of the battery and the temperature of the refrigerating fluid flowing into the liquid cooling plate. According to the invention, the power consumption of the liquid cooling heat management system can be reduced.

Description

Technical Field

[0001] The present disclosure relates to the field of liquid cooling and heat dissipation technology, and in particular to a liquid cooling thermal management system and an energy storage cabinet. Background Art

[0002] With the popularization of renewable energy and the continuous growth of energy demand, energy storage technology has become increasingly important. As an energy storage solution, energy storage cabinets have the advantages of strong environmental adaptability, energy saving and environmental protection.

[0003] Energy storage cabinets are used to convert electrical energy into chemical energy for storage so that it can be released when needed. Therefore, battery modules and power modules are the core parts of energy storage cabinets. Battery modules generate a lot of heat during charging and discharging, and power modules also generate heat during power conversion. Therefore, energy storage cabinets also include thermal management systems, such as liquid cooling thermal management systems.

[0004] At present, with the increase of energy density of energy storage cabinets, the heat dissipation demand inside the energy storage cabinets is also increased, so the power consumption of the liquid cooling thermal management system is also increased. On the basis of meeting the heat dissipation demand of the energy storage cabinets, how to reduce the power consumption of the liquid cooling thermal management system is a problem that technical personnel in this field are committed to solving. Summary of the invention

[0005] The present disclosure provides a liquid cooling thermal management system and an energy storage cabinet, which can reduce the power consumption of the liquid cooling thermal management system on the basis of meeting the heat dissipation requirements of the energy storage cabinet.

[0006] In a first aspect, the present disclosure provides a liquid cooling thermal management system, including a plurality of compressors, a condenser, a plurality of throttle valves, an evaporator, a liquid cooling plate, a radiator, and a plurality of fans;

[0007] The condenser includes a plurality of input ends and a plurality of output ends, and the evaporator includes a plurality of input ends and a plurality of output ends;

[0008] Each of the plurality of compressors is connected between an input end of the condenser and an output end of the evaporator through a pipeline, and each of the plurality of throttle valves is connected between an output end of the condenser and an input end of the evaporator through a pipeline; the pipeline connected to the liquid cooling plate passes through the evaporator, the liquid cooling plate is used to contact the battery, the pipeline connected to the radiator passes through the condenser, and the plurality of fans are arranged at the radiator;

[0009] The compressor is used to increase the pressure of the gaseous refrigerant discharged from the evaporator; the condenser is used to condense the gaseous refrigerant discharged from the compressor into liquid refrigerant; the throttle valve is used to reduce the pressure of the liquid refrigerant discharged from the condenser and to adjust the flow of the liquid refrigerant entering the evaporator; the evaporator is used to perform heat exchange between the refrigerant flowing through the evaporator and the refrigerant flowing through the liquid cooling plate; the liquid cooling plate is used to perform heat exchange with the battery to dissipate heat for the battery; the radiator is used to perform heat exchange between the refrigerant flowing through the condenser and the cooling liquid flowing through the radiator; the multiple fans are used to perform heat exchange between the cooling liquid flowing through the radiator and the air in the environment;

[0010] The liquid cooling thermal management system also includes a controller, which is used to adjust the number and speed of the compressors running among the multiple compressors, and adjust the number and opening degree of the throttle valves opened among the multiple throttle valves according to the temperature of the battery and the temperature of the refrigerant flowing into the liquid cooling plate.

[0011] In the scheme shown in the present disclosure, multiple compressors and multiple throttle valves form multiple parallel refrigeration circuits, and the refrigerant discharged from each refrigeration circuit is almost entirely allocated to the compressor on this refrigeration circuit, so that the theoretical value and actual value of the refrigerant allocated to the compressor are relatively close. Then, the actual speed of the compressor and the design speed will also be relatively close, thereby improving the control accuracy of the compressor and making the compressor operate at better energy efficiency, which is beneficial to reducing the power consumption of the compressor and then reducing the power consumption of the liquid cooling thermal management system.

[0012] In the scheme shown in the present disclosure, the number and speed of the compressors in operation, as well as the number and degree of opening of the throttle valves, are not only related to the temperature of the refrigerant flowing into the liquid cooling plate, but also to the temperature of the battery, which is conducive to stable operation of the compressor, reducing the power consumption of the compressor, protecting the compressor, and extending the service life of the compressor. The reasons are as follows.

[0013] The target freezing temperature that the refrigerant flowing into the liquid cooling plate needs to meet changes with the temperature of the battery. For example, when the temperature of the battery rises, the target freezing temperature also rises. In this way, the temperature difference between the temperature of the refrigerant flowing into the liquid cooling plate and the target freezing temperature is relatively stable (such as a stable change), and the number and speed of the operating compressors are related to the temperature difference between the temperature of the refrigerant and the target freezing temperature. Therefore, when the temperature difference is stable, the operation of the compressor is also stable.

[0014] In one possible implementation, the controller is used to adjust the number and speed of running compressors among the multiple compressors, and adjust the number and opening degree of open throttle valves among the multiple throttle valves according to the temperature of the battery, the temperature of the refrigerant flowing into the liquid cooling plate, and the power consumption of each of the multiple running compressors.

[0015] In a possible implementation, the controller is specifically used to determine a target freezing temperature according to the temperature of the battery;

[0016] Based on the temperature of the refrigerant flowing into the liquid cooling plate being no greater than the target freezing temperature and the sum of the power consumption of each of the multiple running compressors being the lowest, the number and speed of the running compressors among the multiple compressors are adjusted, as well as the number and opening degree of the throttle valves opened among the multiple throttle valves are adjusted.

[0017] In the scheme shown in the present disclosure, on the basis of satisfying the temperature of the refrigerant liquid not exceeding the target freezing temperature, the number of operating compressors and the speed are determined in accordance with the principle of minimizing the total power consumption of the compressors. This is beneficial to reducing the total power consumption of the compressors, thereby reducing the power consumption of the liquid cooling thermal management system and achieving energy-saving optimization of the liquid cooling thermal management system.

[0018] In one possible implementation, the controller is also used to adjust the speed of the fans running among the multiple fans, and / or adjust the number of fans running among the multiple fans according to the temperature of the coolant flowing out of the radiator and a pre-stored target cooling temperature.

[0019] In the scheme shown in the present disclosure, the number of operating fans and / or the speed are adjusted according to the relationship between the temperature of the coolant and the target cooling temperature. This flexible adjustment of the fan operation plan according to the heat dissipation requirements is beneficial to reducing the power consumption of the fan as much as possible while meeting the heat dissipation requirements, thereby facilitating energy saving.

[0020] In a possible implementation, the controller is specifically used to adjust the speed of the fan running among the multiple fans according to the temperature difference between the temperature of the coolant flowing out of the radiator and the target cooling temperature being not within a pre-stored temperature range;

[0021] If the speed of a fan running among the multiple fans is adjusted to a speed limit value, and the temperature difference between the temperature of the coolant flowing out of the radiator and the target cooling temperature is not within the set temperature range, the number of fans running among the multiple fans is adjusted.

[0022] In the scheme shown in the present disclosure, when the temperature difference between the temperature of the coolant and the target cooling temperature is not within the set temperature range, the speed of the fan in operation is adjusted first. If the speed of the fan has been adjusted to the speed limit value, and the temperature difference between the temperature of the coolant and the target cooling temperature is still not within the set temperature range, the number of running fans is further adjusted. This scheme of adjusting the speed of the fan first and then adjusting the number of fans is conducive to reducing the total power consumption of the fan.

[0023] In a possible implementation, the controller is specifically configured to increase the operation of one fan or reduce the operation of one fan if the speed of the fan in operation among the multiple fans is adjusted to a speed limit value and the temperature difference between the temperature of the coolant flowing out of the radiator and the target cooling temperature is not within the set temperature range;

[0024] If the temperature difference between the temperature of the coolant flowing out of the radiator and the target cooling temperature is not within the set temperature range after the number of operating fans is adjusted, the rotation speed of the fans in operation among the multiple fans is adjusted.

[0025] In the scheme shown in the present disclosure, the number of fans is adjusted one by one. For example, one fan is added or reduced first. After the number is adjusted, if the temperature difference between the coolant temperature and the target coolant temperature is still within the set temperature range, the speed is adjusted. This scheme of adjusting the fan operation in the manner of adjusting the speed-adjusting one fan-adjusting the speed is conducive to coping with the scenario where the coolant temperature changes gradually.

[0026] In one possible implementation, the speed limit value includes a lower speed limit value and an upper speed limit value, wherein the lower speed limit value is the minimum speed for the fan to run, and the upper speed limit value is the maximum speed at which the fan can run, or is a set speed that is less than the maximum speed at which the fan can run.

[0027] In one possible implementation, the controller is also used to adjust the speed of the fans running among the multiple fans, and / or adjust the number of fans running among the multiple fans according to the temperature of the coolant flowing out of the radiator, a pre-stored target cooling temperature, and the noise of the fans running among the multiple fans.

[0028] In the scheme shown in the present disclosure, the noise of the fans is also considered when adjusting the number and speed of the fans. For example, based on the relationship between the coolant temperature, the target coolant temperature and the set temperature range, the number and speed of the fans in operation are determined, and then the number and speed of the fans are further adjusted based on the noise conditions of these fans.

[0029] In a possible implementation manner, the rotational speeds of the respective fans among the plurality of fans are the same.

[0030] In a second aspect, an energy storage cabinet is provided, the energy storage cabinet comprising a box body, a plurality of batteries located in the box body, and the liquid cooling thermal management system described in the first aspect;

[0031] The liquid cooling thermal management system is used to dissipate heat for the energy storage cabinet, for example, to dissipate heat for multiple batteries in the energy storage cabinet. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the principle of a liquid cooling thermal management system provided in the prior art;

[0033] Figure 2 is a schematic diagram of a liquid cooling thermal management system provided by an exemplary embodiment of the present disclosure;

[0034] Figure 3 is a flow chart of a control method of a liquid cooling thermal management system provided by an exemplary embodiment of the present disclosure;

[0035] Figure 4 is a schematic diagram of a cooling cycle provided by an exemplary embodiment of the present disclosure;

[0036] Figure 5 is a schematic diagram of an adjustment flow of a wind turbine operation scheme provided by an exemplary embodiment of the present disclosure;

[0037] Figure 6 This is a schematic diagram of the change of the fan speed, the total fan power and the number of running fans along with the heat dissipation load provided by an exemplary embodiment of the present disclosure.

[0038] Description of Reference Numerals

[0039] 100, refrigeration cycle; 200, cooling cycle; 300, cooling cycle.

[0040] 1. Compressor; 1a. First compressor; 1b. Second compressor; 2. Condenser; 3. Throttle valve; 3a. First throttle valve; 3b. Second throttle valve; 4. Evaporator; 5. Liquid cooling plate; 6. Radiator; 7. Fan. DETAILED DESCRIPTION

[0041] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the embodiments of the present disclosure will be further described in detail below with reference to the accompanying drawings.

[0042] This embodiment relates to an energy storage system, which is used to store excess energy and release it at a desired time or in a desired area. The energy storage system can be an electric energy storage system, a thermal energy storage system, or a kinetic energy storage system. This embodiment does not limit what type of energy is stored in the energy storage system, and for ease of introduction, an electric energy storage system is used as an example.

[0043] The electric energy storage system may be a system that stores electric energy provided by at least one of city electricity, wind energy, solar energy, nuclear energy, and generators.

[0044] In terms of application, the electric energy storage system can be used in the fields of electricity, communication, transportation and medical treatment, and this embodiment does not limit the application scenarios of the energy storage system. Among them, the energy storage system is generally arranged in an energy storage cabinet, which can be an energy storage container.

[0045] Since the energy storage cabinet is used to convert electrical energy into chemical energy and store it in batteries, the energy storage cabinet mainly includes batteries and related devices. Since batteries generate heat during charging and discharging, the energy storage cabinet also includes a thermal management system to dissipate heat from the batteries.

[0046] Among them, the thermal management system of the energy storage cabinet is generally an air-cooled thermal management system or a liquid-cooled thermal management system, or a combination of an air-cooled thermal management system and a liquid-cooled thermal management system.

[0047] Since the heat dissipation and cooling effect of the liquid cooling thermal management system is better than that of the air cooling thermal management system, the liquid cooling thermal management system is generally used in energy storage cabinets with high energy density.

[0048] With the demand for high energy density of energy storage cabinets, the energy density of current energy storage cabinets has gradually reached 3 megawatt-hours per cubic meter (MWh / m 3 ), and even achieved 5MWh / m 3 or 6MWh / m 3 Or larger. The higher the energy density of the energy storage cabinet, the greater its heat dissipation requirements.

[0049] With the high heat dissipation requirements of the energy storage cabinet, the number of compressors included in the liquid cooling thermal management system of the energy storage cabinet will increase, for example, from the original single compressor cooling to dual compressor cooling, or even more compressor cooling. The number of fans will also increase, for example, from the original three fans to a larger number of fans.

[0050] The total energy consumption of the liquid cooling thermal management system will also increase in the application of multiple compressors and / or multiple fans. How to reduce the total power consumption of the liquid cooling thermal management system as much as possible while meeting the heat dissipation requirements of the energy storage cabinet is a problem that technicians are committed to solving.

[0051] The current liquid cooling thermal management system has room for energy saving optimization on the refrigeration side, the cooling side and / or the cooling side, which can be specifically referred to as follows.

[0052] like Figure 1 The schematic diagram of the principle of the liquid cooling thermal management system in the prior art is shown in FIG. Figure 1 As shown, the liquid cooling thermal management system mainly includes three cycles, namely, a refrigeration cycle 100, a cold-carrying cycle 200 and a cooling cycle 300, wherein the refrigeration cycle 100 is used to generate cold, the cold-carrying cycle 200 is used to transfer the cold generated by the refrigeration cycle 100 to the battery to dissipate heat from the battery, and the cooling cycle 300 is used to discharge the heat generated by the refrigeration cycle 100 and the cold-carrying cycle 200.

[0053] Continue to refer Figure 1 As shown, the refrigeration cycle 100 mainly includes a compressor 1, a condenser 2, a throttle valve 3 and an evaporator 4. The output end of the compressor 1 is connected to the input end of the condenser 2 through a pipeline, the output end of the condenser 2 is connected to the input end of the throttle valve 3 through a pipeline, the output end of the throttle valve 3 is connected to the input end of the evaporator 4 through a pipeline, and the output end of the evaporator 4 is connected to the input end of the compressor 1 through a pipeline, so that a refrigeration circuit of the refrigeration cycle is formed between the compressor 1, the condenser 2, the throttle valve 3 and the evaporator 4.

[0054] The compressor 1 is used as the core component of the refrigeration cycle 100 to compress the low-pressure gaseous refrigerant (wherein the refrigerant is also called refrigerant) into a high-pressure gaseous refrigerant. The condenser 2 is used to condense the gaseous refrigerant into a liquid refrigerant. The throttle valve 3 is used to reduce the pressure of the liquid refrigerant and adjust the flow of the refrigerant entering the evaporator 4. The evaporator 4 is used to evaporate the liquid refrigerant into a gaseous refrigerant and circulate it to the compressor 100.

[0055] Continue to refer Figure 1 As shown, the refrigeration cycle 100 includes a plurality of compressors 1 ( Figure 1 In the example of two compressors 1, multiple compressors 1 are connected in parallel between the evaporator 4 and the condenser 2. For example, the output end of the evaporator 4 is connected to the input ends of multiple compressors 1, and the output end of the condenser 2 is connected to the output ends of multiple compressors 1. Multiple compressors 1 are on the same refrigeration circuit. Then, the gaseous refrigerant discharged from the evaporator 4 is distributed to multiple compressors 1, which are used to increase the pressure to produce cooling capacity.

[0056] Depend on Figure 1It can be seen that although the refrigeration cycle 100 includes multiple compressors 1, since there is only one throttle valve 3, only one refrigeration circuit can be formed. Therefore, when the heat dissipation demand of the cold cycle changes, when adjusting the speed of the compressor 1, all the compressors 1 can only be regarded as a whole and the speeds of these compressors can be adjusted.

[0057] For example, when the heat dissipation demand of the cold-carrying cycle changes, the control end of the energy storage cabinet, such as the controller of the energy management system, will adjust the opening of the throttle valve 3. When the opening of the throttle valve 3 changes, the amount of refrigerant flowing to the evaporator 4 changes, and thus the total amount of refrigerant discharged from the evaporator 4 changes. Therefore, the speed of the compressor 1 also needs to be adjusted.

[0058] The controller generally determines the rotation speed of each compressor 1 according to a strategy of evenly distributing the total refrigerant discharged from the evaporator 4 to the multiple compressors 1 and minimizing the power consumption of the total compressors.

[0059] However, in actual applications, due to the influence of pipeline layout and the flow resistance of refrigerant in the pipeline, the total refrigerant discharged from the evaporator 4 will not be evenly distributed to multiple compressors 1. Therefore, it is easy for some compressors 1 to be allocated more refrigerant, while other compressors 1 are allocated less refrigerant. The actual speed of compressor 1 will be affected by the refrigerant, so the actual speed of compressor 1 will deviate from the design speed. The design speed is the optimal speed calculated based on refrigeration and energy-saving strategies. If the actual speed of compressor 1 deviates from the design speed, compressor 1 is likely to not operate in the maximum efficiency and optimal operating mode, which may easily lead to a large total energy consumption of the compressor.

[0060] In addition, compressors that are allocated more refrigerant are prone to overload operation, while compressors that are allocated less refrigerant are prone to underload operation.

[0061] The above is a situation where the refrigeration cycle 100 of the current liquid cooling thermal management system has high energy consumption.

[0062] Continue to refer Figure 1 As shown, the cooling cycle 200 mainly includes a liquid cooling plate 5, a water pump and a water tank. The liquid cooling plate 5, the water tank and the water pump are connected to form a circulation loop through a pipeline. The water pump is used to pump water in the water tank into the liquid cooling plate 5. The liquid cooling plate 5 is arranged in contact with the battery so that heat exchange can be performed between the liquid cooling plate and the battery. Figure 1 As shown, the pipes of the cold-carrying cycle 200 are in contact with or connected to the evaporator 4 , for example, the pipes of the cold-carrying cycle pass through the evaporator, so that the refrigerant flowing through the evaporator exchanges heat with the refrigerant flowing through the liquid cooling plate 5 to absorb the cold near the evaporator 4 .

[0063] Among them, because the liquid (generally water) flowing in the pipe of the cooling cycle 200 has a lower temperature after absorbing the cold near the evaporator, the water flowing in the pipe of the cooling cycle 200 is called refrigerant or chilled water. The refrigerant flowing into the liquid cooling plate 5 can be recorded as refrigerated supply water, and the refrigerant flowing out of the liquid cooling plate 5 can be recorded as refrigerated return water.

[0064] In this way, the heat generated by the battery is absorbed by the refrigerant in the liquid cooling plate 5, and the battery is cooled. The chilled return water discharged from the liquid cooling plate flows to the evaporator and exchanges heat with the refrigerant flowing in the evaporator. For example, the chilled return water absorbs the heat released by the phase change of the refrigerant, and the cooled chilled supply water flows into the liquid cooling plate 5 again to dissipate heat for the battery.

[0065] Among them, the cooling cycle 200 is provided with a temperature sensor near the input end of the liquid cooling plate 5 to monitor the temperature of the refrigerant in the cooling cycle 200. This temperature is recorded as the refrigerated water supply temperature in order to distinguish it from the temperature of the coolant in the cooling cycle. Of course, the cooling cycle 200 can also be provided with a temperature sensor near the output end of the liquid cooling plate 5 to monitor the refrigerated return water temperature of the cooling cycle 200.

[0066] The cooling capacity of the refrigeration cycle 100 is related to the refrigeration water supply temperature or the refrigeration return water temperature of the cold-carrying cycle 200. For example, when the refrigeration water supply temperature of the cold-carrying cycle 200 is high, such as higher than the target freezing temperature, the cooling capacity of the refrigeration cycle 100 will increase accordingly. The increase in the cooling capacity of the refrigeration cycle 100 is related to the opening of the throttle valve 3 and the rotation speed of the compressor 1.

[0067] Currently, the target freezing temperature of the refrigeration cycle 200 is generally a fixed value, for example, the target freezing temperature is 20 degrees, then the operation plan of the refrigeration cycle 100 is determined according to the difference between the freezing water supply temperature of the refrigeration cycle 200 and the target freezing temperature.

[0068] In one scenario, when the heat dissipation demand of the battery is relatively large, the liquid cooling plate 5 absorbs the heat of the battery, causing the temperature of the chilled water supply at the input end of the liquid cooling plate 5 to continue to rise. Then, the difference between the chilled water supply temperature of the cold cycle 200 and the target freezing temperature will continue to increase. In this case, the speed of the compressor will continue to increase, which is not conducive to the stable operation of the compressor. The energy efficiency ratio (coefficient of performance, COP) of the compressor is not high. This situation will also cause the power consumption of the liquid cooling thermal management system to be relatively large.

[0069] The above is a case where the power consumption of the liquid cooling thermal management system caused by the cooling cycle 200 is relatively large.

[0070] Continue to refer Figure 1As shown, the cooling cycle 300 includes a radiator 6, a plurality of fans 7 and a water pump, wherein the radiator 6 and the water pump form a circulation loop through a pipeline, and a plurality of fans 7 are arranged near the radiator 6, and the fans are used to exchange heat between the radiator and the air. The pipeline of the cooling cycle is in contact with or connected to the condenser 2, for example, the pipeline where the radiator is located passes through the condenser 2. In this way, the radiator absorbs the heat discharged by the refrigeration cycle 100, and discharges the absorbed heat to the outside of the energy storage cabinet through the fan.

[0071] The liquid (usually water) flowing in the cooling cycle 300 pipe is used for heat dissipation and cooling, so the water flowing in the cooling cycle pipe is recorded as coolant. Figure 1 As shown, the coolant flowing into the radiator 6 is recorded as cooling supply water, and the coolant flowing out of the radiator is recorded as cooling return water.

[0072] So, reference Figure 1 As shown, the condenser converts gaseous refrigerant into liquid refrigerant to release heat. The released heat is absorbed by the cooling return water flowing out of the radiator. The cooling supply water that absorbs the heat flows into the radiator. The heat absorbed by the cooling supply water is dissipated into the environment through the fan. The cooling return water after heat dissipation flows to the condenser again.

[0073] However, the multiple fans 7 included in the current cooling cycle 300 are generally turned on and stopped at the same time to quickly discharge the heat generated by the liquid cooling thermal management system into the environment. That is, all the fans in the cooling cycle are generally either in operation at the same time or in a stopped state at the same time.

[0074] However, when all fans 7 of the cooling cycle 300 are running at the same time, it is easy to cause the heat dissipation to be greater than the heat dissipation demand, which leads to excessive total power consumption of the fans, resulting in a large total power consumption of the liquid cooling thermal management system.

[0075] The present embodiment provides a liquid cooling thermal management system, the refrigeration cycle 100 of which includes multiple refrigeration circuits, each of which is independent of each other. The compressor and throttle valve on each refrigeration circuit are independently controlled, and the compressor and throttle valve are matched one by one to reduce the deviation between the design speed and the actual speed of the compressor, achieve precise control of the compressor, maximize the power consumption and optimal operation of the compressor, and reduce the power consumption of the compressor.

[0076] The target freezing temperature of the cooling cycle of the liquid cooling thermal management system is a variable value related to the temperature of the battery, which is conducive to the stable operation of the compressor. The cooling cycle of the liquid cooling thermal management system has a fan operation related to the cooling return water temperature of the cooling cycle, and changes with the cooling return water temperature, which is conducive to achieving the minimum fan power consumption on the basis of meeting the heat dissipation requirements, thereby reducing the total power consumption of the liquid cooling thermal management system.

[0077] The liquid cooling thermal management system shown in this embodiment will be described in detail below.

[0078] like Figure 2 The following is a schematic diagram of the principle of the liquid cooling thermal management system. Figure 2 As shown, the liquid cooling thermal management system includes a refrigeration cycle 100, a cooling cycle 200 and a cooling cycle 300. The specific functions of the three are referred to above and will not be repeated here. The following first introduces the scenario of the liquid cooling thermal management system cooling the battery, and then introduces the characteristics of the refrigeration cycle 100, the cooling cycle 200 and the cooling cycle 300 of the liquid cooling thermal management system respectively.

[0079] In one example, a temperature sensor is arranged near the battery to monitor the battery temperature. The controller of the energy management system (EMS) of the energy storage cabinet obtains the battery temperature. The controller stores the target operating temperature of the battery. Then, when the controller detects that the battery temperature exceeds the target operating temperature, it controls the liquid cooling thermal management system to start and dissipate heat for the battery. When the controller detects that the battery temperature does not exceed the target operating temperature, it controls the liquid cooling thermal management system to stop dissipating heat for the battery.

[0080] Among them, the liquid cooling thermal management system is controlled to start, for example, the water pump in the liquid cooling thermal management system is first controlled to run, and then the fan is controlled to run, and then the compressor is controlled to run, or the fan is controlled to run first, and then the water pump is controlled to run, and then the compressor is controlled to run.

[0081] Among them, the liquid cooling thermal management system is controlled to stop running, for example, the compressor is controlled to stop running first, then the fan is controlled to stop running, and finally the water pump is controlled to stop running.

[0082] In one example, based on energy conservation considerations, in a scenario where the ambient temperature is relatively low, such as in winter when the temperature is relatively low, if the battery temperature does not exceed the target operating temperature by much, the low temperature environment can be used to dissipate heat for the battery first. When the temperature exceeds the target operating temperature by a large amount, the liquid cooling thermal management system can be used to dissipate heat for the battery. Similarly, in winter when the temperature is relatively low, the liquid cooling thermal management system can reduce the battery temperature to close to the target operating temperature while dissipating heat for the battery. The remaining temperature difference can be used to dissipate heat for the battery by the low temperature environment. Then, accordingly, Figure 3 As shown, the start and stop of the liquid cooling thermal management system can be performed according to the following steps. Among them, the execution subject can be a controller in the energy management system.

[0083] In step 310 , the controller obtains the temperature of the environment where the battery is located and the temperature of the battery.

[0084] The ambient temperature and the battery temperature are both obtained from temperature sensors. For example, a temperature sensor is arranged around the battery to monitor the ambient temperature around the battery. A temperature sensor is arranged in the heat generating area of ​​the battery to monitor the temperature of the battery.

[0085] After the controller obtains the ambient temperature of the battery and the temperature of the battery, it can control the start and stop of the liquid cooling thermal management system according to the ambient temperature and the temperature of the battery.

[0086] For example, in step 320, after the controller obtains the ambient temperature of the battery, it can determine the start-stop trigger temperature for controlling the start and stop of the liquid cooling thermal management system based on the ambient temperature and the pre-stored target operating temperature of the battery.

[0087] As an example, when the ambient temperature is not higher than the target operating temperature, the start-stop trigger temperature may be a temperature higher than the target operating temperature; when the ambient temperature is higher than the target operating temperature, the start-stop trigger temperature may be a temperature not higher than the target operating temperature.

[0088] For example, if the target operating temperature of the battery is 20 degrees, then when the ambient temperature is 10 degrees, the start-stop trigger temperature may be a temperature value higher than 20 degrees, such as 25 degrees. For another example, when the ambient temperature is 35 degrees, the start-stop trigger temperature may be a temperature value not higher than 20 degrees, such as 15 degrees or 20 degrees.

[0089] In step 330, the controller obtains the temperature of the battery, and after determining the start-stop trigger temperature, determines whether the temperature of the battery is higher than the start-stop trigger temperature. For example, when it is detected that the temperature of the battery is higher than the start-stop trigger temperature, step 340 is executed. In step 340, the controller controls the liquid cooling thermal management system to start running to dissipate heat from the battery, and when the controller detects that the temperature of the battery is not higher than the start-stop trigger temperature, step 350 is executed, in which the liquid cooling thermal management system is controlled to stop running.

[0090] For example, in a scenario with low ambient temperature, such as when the ambient temperature (such as 10 degrees) is lower than the target operating temperature (such as 20 degrees), the liquid cooling thermal management system is cooling the battery. When it detects that the battery temperature (such as 25 degrees) is still greater than the target operating temperature (such as 20 degrees), but has reached the start-stop trigger temperature (such as 25 degrees), the liquid cooling thermal management system will stop cooling the battery, and the temperature difference between the battery temperature and the target operating temperature will be adjusted by the low temperature environment.

[0091] In the scenario where the ambient temperature is relatively low, the liquid cooling thermal management system is currently in a stopped state. If the controller detects that the battery temperature (such as 23 degrees) exceeds the target operating temperature (such as 20 degrees), but has not exceeded the start-stop trigger temperature (such as 25 degrees), the controller will not control the liquid cooling thermal management system to dissipate heat for the battery. The temperature difference between the battery temperature and the target operating temperature will be adjusted by the low temperature environment first.

[0092] For another example, in a scenario where the ambient temperature is relatively high, such as when the ambient temperature (such as 35 degrees) is higher than the target operating temperature (such as 20 degrees), the start-stop trigger temperature of the controller controlling the start and stop of the liquid cooling thermal management system can be the target operating temperature, or a temperature value lower than the target operating temperature.

[0093] This method of dissipating heat from the battery through a liquid cooling thermal management system and ambient temperature helps reduce the total power consumption of the liquid cooling thermal management system.

[0094] In one example, in order to avoid frequent starting and stopping of the liquid cooling thermal management system, the controller may control the start and stop of the liquid cooling thermal management system in one way: when the battery temperature is detected to be higher than the start-stop trigger temperature within a preset time, the liquid cooling thermal management system is controlled to start; when the battery temperature is detected to be lower than the start-stop trigger temperature within a preset time, the liquid cooling thermal management system is controlled to stop. Another way may be: when the battery temperature is detected to be higher than the start-stop trigger temperature and the temperature difference is greater than a preset value, the liquid cooling thermal management system is controlled to start; when the battery temperature is detected to be lower than the start-stop trigger temperature and the temperature difference is greater than a preset value, the liquid cooling thermal management system is controlled to stop.

[0095] This method of controlling the start and stop of the liquid-cooled thermal management system is conducive to the stable operation of the liquid-cooled thermal management system. The stable operation of the liquid-cooled thermal management system is conducive to extending the service life of the components in the liquid-cooled thermal management system and is also conducive to reducing the total power consumption of the liquid-cooled thermal management system.

[0096] The above is an introduction to the start and stop scenarios of the liquid cooling thermal management system. The following introduces the characteristics of the refrigeration cycle, cold load cycle and cooling cycle respectively.

[0097] (a) Characteristics of refrigeration cycle 100.

[0098] refer to Figure 2 As shown, the refrigeration cycle 100 includes a compressor 1, a condenser 2, a throttle valve 3 and an evaporator 4, wherein the number of the compressor 1 and the throttle valve 3 are both multiple and equal, the number of the condenser 2 and the evaporator 4 can be one, but the condenser 2 includes multiple input ends and multiple output ends, and the evaporator 4 also includes multiple input ends and multiple output ends.

[0099] Continue to refer Figure 2 As shown, the input end of each compressor 1 is connected to an output end of the evaporator 4 through a pipeline, and the output end of each compressor 1 is connected to an input end of the condenser 2 through a pipeline. It should be pointed out that different output ends of the evaporator 4 are connected to different compressors 1, and different input ends of the condenser 2 are connected to different compressors 1. It can also be understood that the output ends of the compressor 1 and the evaporator 4 are connected one by one, and the input ends of the compressor 1 and the condenser 2 are connected one by one.

[0100] The input end of each throttle valve 3 is connected to an output end of the condenser 2 through a pipeline, and the output end of each throttle valve 3 is connected to an input end of the evaporator 4 through a pipeline. It should be pointed out that different output ends of the condenser 2 are connected to different throttle valves 3, and different input ends of the evaporator 4 are connected to different throttle valves 3. It can also be understood that the throttle valve 3 and the output ends of the condenser 2 are connected one by one, and the throttle valve 3 and the input ends of the evaporator 4 are connected one by one.

[0101] Continue to refer Figure 2 As shown, the compressor 1 and the throttle valve 3 correspond one to one, each compressor 1 and a throttle valve 3 are located on the same circulation pipeline, different compressors 1 are located on different circulation pipelines, and different throttle valves 3 are located on different circulation pipelines. Each circulation pipeline serves as a refrigeration circuit, so that the refrigeration cycle 100 forms a plurality of refrigeration circuits connected in parallel.

[0102] refer to Figure 2 As shown, a refrigeration circuit (referred to as the first refrigeration circuit) is formed between the first compressor 1a, the first throttle valve 3a, the condenser 2 and the evaporator 4, and another refrigeration circuit (referred to as the second refrigeration circuit) is formed between the second compressor 1b, the second throttle valve 3b, the condenser 2 and the evaporator 4. The two refrigeration circuits are independent of each other. For example, the refrigerant discharged from the first throttle valve 3a is all compressed by the first compressor 1a, and the refrigerant discharged from the second throttle valve 3b is all compressed by the second compressor 1b. In this way, the refrigerant discharged from the evaporator 4 does not have a free distribution, so that the speed of the first compressor 1a can accurately match the opening of the first throttle valve 3a, and the speed of the second compressor 1b can accurately match the opening of the second throttle valve 3b.

[0103] For example, when the controller calculates the speed of the first compressor, it is determined based on the condition that all the refrigerant discharged from the first throttle valve 3a is discharged to the first throttle valve 3a. In fact, almost all the refrigerant discharged from the first throttle valve 3a is discharged to the first throttle valve 3a. Therefore, the design speed of the first compressor is close to the actual speed. Then, the first compressor can play the maximum effect and operate in the optimal operation mode, thereby improving the energy efficiency ratio (coefficient of performance, COP) of the first compressor and reducing the power consumption of the first compressor. Similarly, the refrigeration efficiency of the second compressor can also be improved and the power consumption of the second compressor can be reduced.

[0104] Moreover, because Figure 2 In the scheme shown, different refrigeration circuits are independent of each other, so the opening of the throttle valve is only affected by the speed of the compressor on the refrigeration circuit, and is not affected by the speed of the compressors on other refrigeration circuits. The speed of the compressor is also only affected by the opening of the throttle valve on the refrigeration circuit, and is not affected by the opening of the throttle valve on other refrigeration circuits. This makes the adjustment of the compressor operation scheme of the refrigeration cycle more flexible.

[0105] Moreover, if Figure 2 In the scheme shown, the refrigeration cycle 100 includes multiple refrigeration circuits. Therefore, even if a fault occurs in one of the refrigeration circuits, such as a throttle valve 3 fault or a compressor fault, the refrigeration cycle can still operate normally, and the impact on the entire liquid cooling thermal management system is relatively small, thereby making the operation stability of the liquid cooling thermal management system better.

[0106] It should be noted that the openings of the throttle valves 3 on different refrigeration circuits may be equal or unequal. The rotation speeds of the compressors on different refrigeration circuits may be equal or unequal.

[0107] Regarding the setting of the compressor operation plan of the refrigeration cycle 100. The compressor operation plan includes the number of compressors in operation and the speed. It should be noted that when the number of compressors in operation and the speed are adjusted, the number and degree of opening of the throttle valves will also be adjusted synchronously. For example, if one more compressor is added to the operation, the throttle valve on the refrigeration circuit where the added compressor is located needs to be opened, and the speed of the compressor matches the opening of the throttle valve.

[0108] Since the cooling energy generated by the refrigeration cycle 100 is used to dissipate heat for the battery, the compressor operation plan can be determined according to the heat dissipation demand of the battery. The heat dissipation demand of the battery can be measured by the relationship between the temperature of the battery and the target operating temperature mentioned above.

[0109] Since the cold energy generated by the refrigeration cycle 100 is carried to the battery through the cold-carrying cycle 200 to dissipate heat for the battery, and the heat transfer between the liquid cooling plate of the cold-carrying cycle 200 and the battery takes time, it may happen that although the temperature of the liquid cooling plate is very low, the temperature of the battery is still relatively high. If the compressor operation plan is determined according to the battery temperature, oversupply is likely to occur.

[0110] Therefore, the compressor operation scheme can be determined according to the relationship between the temperature of the refrigerant of the cold cycle 200 (such as the freezing water supply temperature) and the target freezing temperature. For example, if the freezing water supply temperature is lower than the target freezing temperature and the temperature difference exceeds the preset range, indicating that the freezing water supply temperature is much lower than the target freezing temperature, then the compressor operation scheme may be to suspend the operation of the compressor, or reduce the number of compressors in operation, and / or reduce the speed of the compressor. If the freezing water supply temperature is lower than the target freezing temperature, and the temperature difference is within the preset range, and the surface freezing water supply temperature is slightly lower than the target freezing temperature, then the compressor operation scheme may be to continue to operate according to the existing scheme, or to reduce the speed of the compressor. If the freezing water supply temperature is higher than the target freezing temperature, and the temperature difference exceeds the preset range, indicating that the freezing water supply temperature is much higher than the target freezing temperature, then the compressor operation scheme may be to increase the compressor speed, or to increase the number of compressors in operation. If the freezing water supply temperature is higher than the target freezing temperature, and the temperature difference is within the preset range, indicating that the freezing water supply temperature is slightly higher than the target freezing temperature, then the compressor operation scheme may be to continue to operate according to the existing scheme, or to increase the speed of the compressor.

[0111] However, no matter how the compressor operation plan is adjusted, it is determined on the basis of meeting the water supply temperature and water supply flow of the refrigeration cycle and the lowest total power consumption of the compressor.

[0112] In determining the compressor operation plan, the controller can first obtain the refrigeration water supply temperature of the refrigeration cycle, and then determine at least one candidate compressor operation plan based on the refrigeration water supply temperature and the target refrigeration temperature, and then calculate the total power consumption of the compressor corresponding to each candidate compressor operation plan, and then use the candidate compressor operation plan with the lowest total power consumption as the compressor operation plan. Then the controller can control the refrigeration cycle according to the determined compressor operation plan.

[0113] It should be pointed out that the total power consumption of the compressor is affected by the ambient temperature, water temperature and system load rate, so these factors need to be taken into account when calculating the total power consumption of the compressor.

[0114] It should be pointed out that the above compressor operation plan formulation strategy can be applied in Figure 2 The refrigeration cycle shown can also be used in Figure 1In the refrigeration cycle shown, that is, the strategy for formulating the compressor operation plan is not limited to the application of Figure 2 In the refrigeration cycle shown.

[0115] The above is an introduction to the characteristics of the refrigeration cycle 100. The characteristics of the cooling cycle 200 will be introduced below.

[0116] (ii) Characteristics of the cooling cycle 200.

[0117] refer to Figure 2 As shown, the cooling cycle 200 mainly includes a liquid cooling plate 5, a water pump and a water tank. The liquid cooling plate is in contact with the battery to exchange heat with the battery. The liquid cooling plate, the water pump and the water tank are connected in series through pipelines. The water pump is used to pump the refrigerant in the water tank into the liquid cooling plate, so that the refrigerant circulates in the pipeline.

[0118] As mentioned above, the formulation of the compressor operation plan mainly depends on the relationship between the water temperature of the cooling cycle 200 and the target water temperature, wherein the water temperature can be the refrigeration water supply temperature or the refrigeration return water temperature. For the convenience of introduction, the water temperature is the refrigeration water supply temperature and the target water temperature is the target refrigeration temperature. The target refrigeration temperature in this embodiment is a variable value, for example, it can be a variable value related to the temperature of the battery.

[0119] For example, the target freezing temperature of the refrigeration cycle is positively correlated with the temperature of the battery. Then, as the temperature of the battery continues to rise, the target freezing temperature will also rise, so that the difference between the refrigeration water supply temperature of the refrigeration cycle and the target freezing temperature will not increase sharply or continue to increase. Furthermore, during operation, the compressor will not experience a sharp increase in speed or a continuous increase in speed. The compressor can operate in a relatively stable state, and the refrigeration cycle can dissipate heat for the battery steadily. This can improve the cooling efficiency of the compressor on the one hand, and protect the compressor on the other.

[0120] It should be pointed out that although the target freezing temperature will change with the temperature of the battery, it does not necessarily change linearly. Moreover, the target freezing temperature will not change indefinitely with the temperature of the battery. The target freezing temperature changes within a limited range as the temperature of the battery changes.

[0121] In the case where the target freezing temperature is a variable, the compressor operation plan may be determined as follows.

[0122] First, the controller needs to obtain the temperature of the battery and the temperature of the chilled water supply flowing into the liquid cooling plate. Then, based on the temperature of the battery and the chilled water supply temperature, the controller determines the number of compressors in operation and the speed, as well as the number and degree of opening of the throttle valve. For example, after the controller obtains the temperature of the battery, it can first determine the target freezing temperature based on the temperature of the battery, and then determine the compressor operation plan and the throttle valve opening plan based on the relationship between the chilled water supply temperature and the target freezing temperature. For details, please refer to the above description, which will not be repeated here.

[0123] The above is an introduction to the features of the cooling cycle 200. The features of the cooling cycle 300 will be introduced below.

[0124] (iii) Characteristics of cooling cycle 300.

[0125] refer to Figure 2 As shown, the cooling cycle 300 includes a radiator 6, a fan 7 and a water pump. Different from the prior art in which multiple fans 7 are started and stopped at the same time, the fan operation scheme in the cooling cycle 300 in this embodiment is related to the cooling return water temperature of the cooling cycle 300. The fan operation scheme includes at least one of the number of fans in operation and the fan speed. The cooling return water temperature can be referred to Figure 4 As shown, it is the temperature of the coolant on the main line connecting the output ports of all radiators 6. A temperature sensor can be arranged at the confluence of the output ports of all radiators 6 to monitor the cooling return water temperature of the cooling cycle 300.

[0126] In one example, the controller can obtain the cooling return water temperature of the cooling cycle when the cooling cycle is in operation, and adjust the fan operation plan of the cooling cycle 300 when it is detected that the temperature difference between the cooling return water temperature and the target cooling temperature is not within a pre-stored temperature range.

[0127] Among them, adjusting the fan operation plan can be adjusting the fan speed, adjusting the number of fans in operation, or adjusting the fan speed and the number of fans in operation. Figure 4 As shown, the controller is electrically connected to all the fans to control each fan.

[0128] In one example, the strategy of the controller to adjust the fan operation plan can be executed according to the process shown in Figure 5. In step 510, determine whether the temperature difference between the cooling return water temperature and the target cooling temperature is within the pre-stored temperature range. If so, go to stop adjusting the fan operation plan. If not, go to step 520, and adjust the speed of the fan in operation in step 520. Then go to step 530, and after the fan speed is adjusted, determine again whether the temperature difference between the cooling return water temperature and the target cooling temperature is within the preset temperature range. If so, go to stop adjusting the fan operation plan. If not, for example, after the fan speed is adjusted to the speed limit value, it is detected that the difference between the cooling return water temperature and the target cooling temperature is still not within the pre-stored temperature range, then go to step 540.

[0129] The speed limit value includes the upper speed limit and the lower speed limit, where the lower speed limit is the minimum speed f that allows the fan to run. min The upper speed limit is the maximum speed at which the fan can run. max , or the upper speed limit is less than f max The target speed f set Among them, the target speed f set It may be a set rotation speed (such as a value determined based on experience or a pre-trained model, which will be described later).

[0130] Continue to refer Figure 5 As shown, in step 540, the controller adjusts the number of running fans. The adjustment of the number of running fans can be done one by one, for example, increasing or decreasing one by one. Of course, in the adjustment of the number of fans, multiple fans can also be increased or decreased at the same time. The one-by-one adjustment scheme is more suitable for the scenario where the cooling return water temperature changes gradually, and the simultaneous adjustment scheme of multiple fans is more suitable for the scenario where the cooling return water temperature changes sharply. Technicians in this field can flexibly select the number adjustment scheme according to the actual scenario, and this embodiment does not limit this.

[0131] Continue to refer Figure 5 As shown, after the controller adjusts the number of running fans, it goes to step 550. In step 550, after the number of running fans is adjusted, it is determined whether the temperature difference between the cooling return water temperature and the target cooling temperature is within the preset temperature range. If so, it goes to stop adjusting the fan operation plan. If the temperature difference between the cooling return water temperature and the target cooling temperature is still not within the temperature range after the number of fans is adjusted (such as insufficient adjustment or over-adjustment), it goes to step 510 to adjust the fan speed until the temperature difference between the cooling return water temperature and the target cooling temperature is within the set temperature range.

[0132] Based on Figure 5The processes shown in the figure respectively introduce examples of reducing the number of operating fans and increasing the number of operating fans.

[0133] For example, when the controller detects that the temperature difference between the cooling return water temperature and the target cooling temperature is lower than the set temperature range, the fan speed will be controlled to be reduced first. When the fan speed is reduced, the temperature difference will be monitored to see if it is within the set temperature range. If the temperature difference is detected to be within the set temperature range, the fan speed will be stopped from being reduced to allow the fan to run at the current speed.

[0134] If it is detected that the fan speed has dropped to the lower speed limit, but the temperature difference between the cooling return water temperature and the target cooling temperature is still lower than the temperature range, the controller controls one of the running fans to stop running to achieve machine reduction.

[0135] After the reduction of the number of fans, the fans in operation will run at the lower speed limit. If the controller detects that the temperature difference between the cooling return water temperature and the target cooling temperature is still lower than the set temperature range, it will reduce one more fan until the adjusted temperature difference falls within the set temperature range. If the temperature difference falls within the set temperature range after the reduction of the number of fans, the fan speed after the reduction of the number of fans will be the lower speed limit. If the temperature difference exceeds the set temperature range after the reduction of the number of fans, the fan speed will be increased until the temperature difference falls within the temperature range.

[0136] For another example, if the controller detects that the temperature difference between the cooling return water temperature and the target cooling temperature is higher than the set temperature range, the fan speed will be increased first. While increasing the fan speed, it will monitor whether the temperature difference is within the set temperature range. If it is detected that the temperature difference falls within the set temperature range, the fan speed will be stopped from being increased, so that the fan can run at the current speed.

[0137] If it is detected that the fan speed has increased to the upper speed limit, but the temperature difference between the cooling return water temperature and the target cooling temperature is still higher than the set temperature range, the controller will control one of the non-operating fans to start running to add a fan. After adding a fan, the fan in operation will run according to the upper speed limit. If the controller detects that the temperature difference between the cooling return water temperature and the target cooling temperature is still higher than the set temperature range, it will add another fan until the temperature difference falls within the set temperature range. If the temperature difference falls within the set temperature range after adding a fan, the fan speed after adding a fan will be the upper speed limit. If the temperature difference is lower than the set temperature range after adding a fan, the fan speed will be reduced until the temperature difference falls within the set temperature range.

[0138] It should be pointed out that when multiple fans are in operation, the speeds of these fans are generally equal. Of course, the controller can also control the speed of each fan individually. However, regardless of whether the speeds of the fans are equal, the speed of each fan not only considers the relationship between the temperature difference between the cooling return water temperature and the target cooling temperature and the target cooling temperature, as well as the total power consumption of the fan, but also needs to consider whether the noise generated meets the noise index requirements, and even environmental factors such as ambient temperature and ambient humidity.

[0139] It should be pointed out that the above process is an adjustment strategy for the fan operation plan during the operation of at least one fan in the cooling cycle. As for the number of fans started and the fan speed when the cooling cycle just starts to run, this embodiment does not limit this. For example, the number of running fans and the speed can be controlled according to historical data, or the number of running fans and the speed can be calculated according to the relationship between the temperature difference between the cooling return water temperature and the target cooling temperature and the target temperature range, according to the principle of minimizing the total power consumption of the fans.

[0140] In one example, when the wind turbine operation plan is being adjusted, the total wind turbine power will also change accordingly, for example, Figure 6 As shown, it is a schematic diagram of the changes of various data in the cooling cycle, where Figure 6 In the figure, the heat dissipation load represents the amount of heat that needs to be removed by the cooling cycle, and is related to the temperature difference between the cooling return water temperature and the target cooling temperature, and the relationship between the set temperature range. Figure 6 Where N represents the number of fans in operation.

[0141] For example, if the temperature difference between the cooling return water temperature and the target cooling temperature is higher than the set temperature range, it means that the cooling return water temperature is much higher than the target cooling temperature, and the heat dissipation load is relatively large. For another example, if the temperature difference between the cooling return water temperature and the target cooling temperature is greater than zero, but within the set temperature range, it means that the cooling return water temperature is slightly higher than the target cooling temperature, and the heat dissipation load is relatively small or relatively stable.

[0142] refer to Figure 6 As shown in the figure, when the heat dissipation load curve is constant, the fan speed f does not change, and the total power consumption of the fan is also constant. When the heat dissipation load increases, the fan speed f increases first, and the total power of the fan also increases. When the speed increases to the upper limit of the speed, the heat dissipation load curve is not lowered, or is not lowered to the appropriate range, then a fan is added. At the moment of adding the fan, all fans are running according to the upper limit of the speed, so the total power of the fan will increase. After adding the machine, the total power of the fan decreases because the speed is reduced (as for how much it is reduced, it depends on the size of the heat dissipation load).

[0143] Continue to refer Figure 6As shown in the figure, when the heat dissipation load is reduced, the fan speed will first decrease, and the total fan power will also decrease. When the speed is reduced to the lower limit of the speed, the heat dissipation load is still relatively small, so one fan can be reduced. At the moment of reducing the fan, all fans will operate according to the lower limit of the speed, so the total fan power will decrease. After reducing the fan, the total fan power will increase because the speed is increased (the increase depends on the size of the heat dissipation load).

[0144] It should be pointed out that Figure 6 Each curve in the figure is only used as an example and does not limit the present embodiment. Figure 6 As shown in the figure, the change of the fan speed lags behind the change of the heat dissipation load, because there is a certain delay. Figure 6 The heat dissipation load curve in the figure is only used to indicate that the heat dissipation load has changed. The controller first controls the speed of the fan and then the number of fans. As for the size of the heat dissipation load curve before and after the change, Figure 6 Not indicated.

[0145] Based on the above, and based on Figure 6 It can be seen that the reduction is triggered when the fan speed reaches the lower speed limit and the temperature difference between the cooling return water temperature and the target cooling temperature is not within the temperature range, so the lower speed limit can also be called the reduction trigger speed. The increase is triggered when the fan speed reaches the upper speed limit and the temperature difference between the cooling return water temperature and the target cooling temperature is not within the temperature range, so the upper speed limit can also be called the increase trigger speed.

[0146] As mentioned above, the upper limit value of the fan speed can be the maximum speed that the fan can reach when it is in operation. It is a property of the fan. The upper limit value of the speed can also be set based on experience. For example, it can be the maximum speed f that the fan can reach when it is in operation. max 90% of the speed limit. The speed limit value may also be determined based on an artificial intelligence (AI) model. For example, the speed limit value is determined by a pre-trained fan speed model. The training process of the fan speed model may refer to the following.

[0147] First, training samples are obtained, where the training samples include input samples and output samples. The input samples include the number of running fans, fan speed, total fan power, and the temperature difference between the cooling return water temperature and the target cooling temperature. The output samples are the speed upper limit value (also called the additional machine trigger speed).

[0148] Then, the input sample is input into the initial fan speed model to obtain the upper limit of the speed for the test. After that, the corresponding upper limit of the speed in the output sample and the upper limit of the speed for the test are input into the loss function to obtain the loss value, and then the initial fan speed model is adjusted using the loss value. After multiple rounds of training, the fan speed model can be obtained.

[0149] Then, in the application, the number of running fans, fan speed, total fan power, and the temperature difference between the cooling return water temperature and the target cooling temperature can be input into the trained fan speed model to obtain the upper limit of the speed.

[0150] It should be pointed out that after the upper limit of the speed is determined by the fan speed model, it can also be adjusted according to the specific application scenario of the liquid cooling thermal management system. For example, appropriate adjustments can be made based on one or more parameters in the noise index requirements, the fan power-speed curve, and the fan air volume-speed curve.

[0151] It should be pointed out that when adjusting the fan operation plan, the temperature difference between the cooling return water temperature and the target cooling temperature is also met, and the total power consumption of the fan is minimized within the set temperature range.

[0152] In the disclosed embodiment, the refrigeration cycle of the liquid cooling thermal management system includes not only a plurality of compressors, but also a plurality of throttle valves to form a plurality of refrigeration circuits connected in parallel. The refrigerant discharged from each refrigeration circuit is almost entirely allocated to the compressor on the refrigeration circuit, so that the theoretical value and the actual value of the refrigerant allocated to the compressor are relatively close. Then, the design speed and the actual speed of the compressor will also be relatively close, thereby improving the control accuracy of the compressor and making the compressor operate at better energy efficiency, which is beneficial to reducing the power consumption of the compressor and thus reducing the power consumption of the liquid cooling thermal management system.

[0153] In the disclosed embodiment, the number and speed of the operating compressors, as well as the number and degree of opening of the throttle valves, are not only related to the temperature of the refrigerant flowing into the liquid cooling plate, but also to the temperature of the battery. This is conducive to stable operation of the compressor, reducing the power consumption of the compressor, protecting the compressor, and extending the service life of the compressor.

[0154] Specifically, the target freezing temperature that the refrigerant flowing into the liquid cooling plate needs to meet changes with the temperature of the battery. For example, when the temperature of the battery rises, the target freezing temperature also increases. In this way, the temperature difference between the temperature of the refrigerant flowing into the liquid cooling plate and the target freezing temperature is relatively stable (such as a stable change), and the number and speed of the operating compressor are related to the temperature difference between the temperature of the refrigerant and the target freezing temperature. Therefore, when the temperature difference is stable, the operation of the compressor is also stable.

[0155] In the disclosed embodiment, the multiple fans of the cooling cycle of the cold night heat dissipation system are not started and stopped at the same time, but the number of running fans and the speed of the fans are adjusted according to the temperature difference between the cooling return water temperature and the target cooling temperature, the relationship between the set temperature range, and the total power consumption of the fans. This is conducive to achieving the lowest total power consumption of the fans while meeting the requirements of heat dissipation, which is conducive to reducing the total power consumption of the liquid cooling thermal management system and realizing energy-saving control of the liquid cooling thermal management system.

[0156] In the disclosed embodiment, the start and stop of the liquid cooling thermal management system is not based solely on the relationship between the battery temperature and the target operating temperature, but is based on the ambient temperature, the battery temperature, and the target operating temperature. For example, in a scenario where the ambient temperature is low, the liquid cooling thermal management system stops running after lowering the battery temperature to a temperature slightly higher than the target operating temperature. The small temperature difference between the battery temperature and the target operating temperature can be adjusted by the low temperature environment. This is conducive to reducing the total power consumption of the liquid cooling thermal management system and achieving energy-saving control of the liquid cooling thermal management system.

[0157] This embodiment also provides an energy storage cabinet, which includes a box body, a plurality of batteries located in the box body, and the liquid cooling thermal management system described above. The battery is the core of the energy storage cabinet and is used to store and release electrical energy. The liquid cooling thermal management system is used to dissipate heat for the energy storage cabinet, for example, to dissipate heat for the plurality of batteries in the energy storage cabinet.

[0158] Of course, the energy storage cabinet will also include other systems, such as a battery management system and an energy management system. The battery management system is used to monitor and evaluate the status of the battery to ensure that the charging and discharging of the battery are balanced. The energy management system is used to monitor, manage and optimize the operation of the energy storage system. For example, by real-time collection, analysis and optimization of energy data, it ensures the stable and efficient operation of the energy storage cabinet, while improving energy utilization efficiency and reducing operating costs.

[0159] The above description is only an optional embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A liquid cooling thermal management system, characterized in that: It comprises a plurality of compressors (1), a condenser (2), a plurality of throttle valves (3), an evaporator (4), a liquid cooling plate (5), a radiator (6) and a plurality of fans (7); The condenser (2) comprises a plurality of input ends and a plurality of output ends, the evaporator (4) comprises a plurality of input ends and a plurality of output ends, each compressor (1) of the plurality of compressors is connected between an input end of the condenser (2) and an output end of the evaporator (4) via a pipeline, each throttle valve (3) of the plurality of throttle valves is connected between an output end of the condenser (2) and an input end of the evaporator (4) via a pipeline, the pipeline connected to the liquid cooling plate (5) passes through the evaporator (4), the pipeline connected to the radiator (6) passes through the condenser (2), and the plurality of fans (7) are arranged at the radiator (6); The evaporator is used to allow the refrigerant flowing through the evaporator to perform heat exchange with the refrigerant flowing through the liquid cooling plate; The liquid cooling plate is used to perform heat exchange with the battery to dissipate heat for the battery; the radiator (6) is used to perform heat exchange between the refrigerant flowing through the condenser (2) and the cooling liquid flowing through the radiator; the multiple fans (7) are used to perform heat exchange between the cooling liquid flowing through the radiator (6) and the air in the environment; The liquid cooling thermal management system further comprises a controller, which is used to adjust the number and rotation speed of the compressors (1) in operation among the plurality of compressors (1), and to adjust the number and opening degree of the throttle valves (3) opened among the plurality of throttle valves (3), according to the temperature of the battery and the temperature of the refrigerant flowing into the liquid cooling plate (5).

2. The liquid cooling thermal management system according to claim 1, characterized in that: The controller is used to adjust the number and speed of the compressors (1) in operation among the multiple compressors (1), and adjust the number and opening degree of the throttle valves (3) opened among the multiple throttle valves (3) according to the temperature of the battery, the temperature of the refrigerant flowing into the liquid cooling plate (5), and the power consumption of each compressor (1) in the multiple operating compressors (1).

3. The liquid cooling thermal management system according to claim 2, characterized in that: The controller is specifically used to determine a target freezing temperature according to the temperature of the battery; Based on the temperature of the refrigerant flowing into the liquid cooling plate (5) being no greater than the target freezing temperature and the sum of the power consumption of each compressor (1) among the multiple running compressors (1) being the lowest, the number and rotation speed of the running compressors (1) among the multiple compressors (1) are adjusted, as well as the number and opening degree of the throttle valves (3) opened among the multiple throttle valves (3) are adjusted.

4. The liquid cooling thermal management system according to claim 1, characterized in that: The controller is also used to adjust the rotation speed of the fan (7) running among the multiple fans (7) and / or adjust the number of the fans (7) running among the multiple fans (7) according to the temperature of the coolant flowing out of the radiator (6) and the pre-stored target cooling temperature.

5. The liquid cooling thermal management system according to claim 4, characterized in that: The controller is specifically used to adjust the rotation speed of the fan (7) running among the multiple fans (7) according to the temperature difference between the temperature of the coolant flowing out of the radiator (6) and the target cooling temperature, when the temperature difference is not within the pre-stored temperature range; If the speed of a fan (7) running among the multiple fans (7) is adjusted to a speed limit value, and the temperature difference between the temperature of the coolant flowing out of the radiator (6) and the target cooling temperature is not within the set temperature range, the number of fans running among the multiple fans is adjusted.

6. The liquid cooling thermal management system according to claim 5, characterized in that: The controller is specifically configured to increase the operation of one fan or reduce the operation of one fan if the rotation speed of a fan (7) in operation among the plurality of fans (7) is adjusted to a rotation speed limit value and the temperature difference between the temperature of the coolant flowing out of the radiator (6) and the target cooling temperature is not within the set temperature range; If, after the number of operating fans is adjusted, the temperature difference between the temperature of the coolant flowing out of the radiator (6) and the target cooling temperature is not within the set temperature range, the rotation speed of the fan (7) operating among the multiple fans (7) is adjusted.

7. The liquid cooling thermal management system according to claim 5, characterized in that: The speed limit value includes a lower speed limit value and an upper speed limit value, wherein the lower speed limit value is the minimum speed for the fan to run, and the upper speed limit value is the maximum speed at which the fan can run, or a set speed that is less than the maximum speed at which the fan can run.

8. The liquid cooling thermal management system according to claim 4, characterized in that: The controller is also used to adjust the rotation speed of the fans running among the multiple fans, and / or adjust the number of the fans running among the multiple fans, based on the temperature of the coolant flowing out of the radiator (6), the pre-stored target cooling temperature, and the noise of the fans running among the multiple fans.

9. The liquid cooling thermal management system according to any one of claims 4 to 8, characterized in that: The rotation speeds of the fans among the plurality of fans are the same.

10. An energy storage cabinet, characterized in that: The energy storage cabinet comprises a box body, a plurality of batteries located in the box body, and a liquid cooling thermal management system according to any one of claims 1 to 9; The liquid cooling thermal management system is used to dissipate heat for the energy storage cabinet.

Images