Liquid-cooled thermal management system and energy storage cabinet

Abstract

The present disclosure provides a liquid cooling thermal management system and an energy storage cabinet, and belongs to the technical field of liquid cooling heat dissipation. The liquid cooling thermal management system comprises a plurality of compressors, a condenser, a plurality of throttling valves, an evaporator, a liquid cooling plate, a radiator and a plurality of fans; each compressor is connected by a pipeline between an input end of the condenser and an output end of the evaporator, and each throttling valve is connected by a pipeline between an output end of the condenser and an input end of the evaporator; the pipeline connected with the liquid cooling plate passes through the evaporator, the liquid cooling plate is used to contact the battery, the pipeline connected with the radiator passes through the condenser, and the plurality of fans are arranged at the radiator; the controller of the liquid cooling thermal management system is used to adjust the number and rotating speed of the operating compressors in the plurality of compressors and the number and opening degree of the throttling valves opened in the plurality of throttling valves according to the temperature of the battery and the temperature of the refrigerant flowing into the liquid cooling plate. By adopting the present disclosure, the power consumption of the liquid cooling thermal management system can be reduced.

Description

TECHNICAL FIELD

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

[0002] With the popularity of renewable energy and the growing demand for energy, energy storage technology is becoming increasingly important. Energy storage cabinets, as a kind of energy storage solution, have the advantages of strong environmental adaptability and 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. The battery modules generate a large amount of heat during charging and discharging, and the power modules also generate heat during power conversion. Therefore, the energy storage cabinet also includes a thermal management system, such as a liquid cooling thermal management system.

[0004] At present, with the increase of the energy density of the energy storage cabinet, the heat dissipation demand inside the energy storage cabinet is also increased, and 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 cabinet, how to reduce the power consumption of the liquid cooling thermal management system is a problem that technicians in the field are committed to solving. SUMMARY

[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 demand of the energy storage cabinet.

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

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

[0008] Each compressor in the plurality of compressors is connected by a pipeline between one input end of the condenser and one output end of the evaporator, and each throttling valve in the plurality of throttling valves is connected by a pipeline between one output end of the condenser and one input end of the evaporator; 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 configured to increase the pressure of the gaseous refrigerant discharged from the evaporator; the condenser is configured to condense the gaseous refrigerant discharged from the compressor into liquid refrigerant; the throttling valve is configured to reduce the pressure of the liquid refrigerant discharged from the condenser and adjust the flow of the liquid refrigerant into the evaporator; the evaporator is configured to exchange heat between the refrigerant flowing through the evaporator and the chilled liquid flowing through the liquid cooling panel; the liquid cooling panel is configured to exchange heat with the battery and dissipate heat for the battery; the radiator is configured to exchange heat between the refrigerant flowing through the condenser and the cooling liquid flowing through the radiator; and the plurality of fans is configured to exchange heat between the cooling liquid flowing through the radiator and the air in the environment.

[0010] The liquid cooling thermal management system further comprises a controller configured to adjust the number and rotation speed of the compressors in operation and the number and opening degree of the throttling valves in operation according to the temperature of the battery and the temperature of the chilled liquid flowing into the liquid cooling panel.

[0011] In the scheme shown in the present disclosure, the plurality of compressors and the plurality of throttling valves form a plurality of parallel refrigeration circuits, and the refrigerant discharged from each refrigeration circuit is almost entirely distributed to the compressors in the refrigeration circuit. When the theoretical value and the actual value of the refrigerant distributed to the compressors are close to each other, the actual rotation speed and the design rotation speed of the compressors are also close to each other, thereby improving the control accuracy of the compressors, allowing the compressors to operate at a better energy efficiency, and being conducive to reducing the power consumption of the compressors and the power consumption of the liquid cooling thermal management system.

[0012] In the scheme shown in the present disclosure, the number and rotation speed of the compressors in operation and the number and opening degree of the throttling valves in operation are not only related to the temperature of the chilled liquid flowing into the liquid cooling panel, but also related to the temperature of the battery. This is conducive to stable operation of the compressors, reduction of the power consumption of the compressors, protection of the compressors, and prolongation of the service life of the compressors. The reasons are as follows.

[0013] The target chilled temperature required by the chilled liquid flowing into the liquid cooling panel changes with the temperature of the battery. For example, when the temperature of the battery rises, the target chilled temperature also rises. In this way, the temperature difference between the temperature of the chilled liquid flowing into the liquid cooling panel and the target chilled temperature is relatively stable (e.g., changes stably), and the number and rotation speed of the compressors in operation are related to the temperature difference between the temperature of the chilled liquid and the target chilled temperature. Therefore, when the temperature difference is stable, the operation of the compressors is also stable.

[0014] In a possible implementation, the controller is configured to adjust the number and rotation speed of the running compressors in the plurality of compressors and adjust the number and opening degree of the open throttles in the plurality of throttles according to the temperature of the battery, the temperature of the refrigerant flowing into the liquid cooling plate, and the power consumption of each compressor in the plurality of running compressors.

[0015] In a possible implementation, the controller is specifically configured to determine a target refrigeration temperature according to the temperature of the battery.

[0016] The number and rotation speed of the running compressors in the plurality of compressors and the number and opening degree of the open throttles in the plurality of throttles are adjusted according to the temperature of the refrigerant flowing into the liquid cooling plate, the temperature of the refrigerant flowing into the liquid cooling plate being not greater than the target refrigeration temperature, and the sum of the power consumptions of each compressor in the plurality of running compressors being the lowest.

[0017] In the scheme shown in the present disclosure, the number and rotation speed of the compressors are determined according to the principle that the total power consumption of the compressors is the lowest on the basis that the temperature of the refrigerant is not greater than the target refrigeration temperature, which is beneficial to reduce 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 a possible implementation, the controller is further configured to adjust the rotation speed of the running fans in the plurality of fans and / or adjust the number of the running fans in the plurality of fans according to the temperature of the cooling liquid flowing out of the radiator and the pre-stored target cooling temperature.

[0019] In the scheme shown in the present disclosure, the number and / or rotation speed of the fans are adjusted according to the relationship between the temperature of the cooling liquid and the target cooling temperature, and this flexible adjustment scheme of the number and / or rotation speed of the fans according to the heat dissipation demand is beneficial to reduce the power consumption of the fans as much as possible on the basis of meeting the heat dissipation demand, thereby being beneficial to energy saving.

[0020] In a possible implementation, the controller is specifically configured to adjust the rotation speed of the running fans in the plurality of fans according to the temperature difference between the temperature of the cooling liquid flowing out of the radiator and the target cooling temperature not being within the pre-stored temperature range.

[0021] If the rotation speed of the running fans in the plurality of fans is adjusted to the rotation speed limit value, and the temperature difference between the temperature of the cooling liquid flowing out of the radiator and the target cooling temperature is not within the set temperature range, the number of the running fans in the plurality of fans is adjusted.

[0022] In the scheme shown in the present disclosure, if the temperature difference between the temperature of the cooling liquid and the target cooling temperature is not within the set temperature range, the speed of the fan in operation is first adjusted, and if the speed of the fan has been adjusted to the speed limit value, and the temperature difference between the temperature of the cooling liquid flowing out of the radiator and the target cooling temperature is still not within the set temperature range, the number of fans in operation is further adjusted. This scheme of first adjusting the speed of the fan 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, if the speed of the fan in operation in the plurality of fans is adjusted to the speed limit value, and the temperature difference between the temperature of the cooling liquid flowing out of the radiator and the target cooling temperature is not within the set temperature range, increase or decrease the number of fans in operation;

[0024] If the number of fans in operation is adjusted, and the temperature difference between the temperature of the cooling liquid flowing out of the radiator and the target cooling temperature is not within the set temperature range, the speed of the fan in operation in the plurality of 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 first increased or decreased in operation, and after the number of fans is adjusted, the temperature difference between the temperature of the cooling liquid and the target cooling liquid temperature is still not within the set temperature range, and then the speed is adjusted. This way of adjusting the operation of the fan according to the adjustment of the speed-adjustment of one fan-adjustment of the speed is conducive to coping with the scene of gradual change of the temperature of the cooling liquid.

[0026] In a 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 at which the fan can operate, and the upper speed limit value is the maximum speed at which the fan can operate, or a set speed less than the maximum speed at which the fan can operate.

[0027] In a possible implementation, the controller is further configured to adjust the speed of the fan in operation in the plurality of fans and / or the number of fans in operation according to the temperature of the cooling liquid flowing out of the radiator, the pre-stored target cooling temperature, and the noise of the fan in operation in the plurality of fans.

[0028] In the scheme shown in the present disclosure, the noise of the fan is also considered when adjusting the number and speed of the fan, for example, after determining the number and speed of the fan based on the relationship among the temperature of the cooling liquid, the target cooling liquid temperature and the set temperature range, the number and speed of the fan are further adjusted based on the noise of the fan.

[0029] In a possible implementation, the rotational speeds of each of the multiple fans in operation are the same.

[0030] In a second aspect, a storage cabinet is provided, which includes a cabinet body, and a plurality of batteries and the liquid cooling thermal management system of the first aspect in the cabinet body.

[0031] The liquid cooling thermal management system is used for heat dissipation of the storage cabinet, for example, heat dissipation of the plurality of batteries in the storage cabinet. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a schematic diagram 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 in an example embodiment of the present disclosure;

[0034] Figure 3 is a schematic diagram of a control method of a liquid cooling thermal management system provided in an example embodiment of the present disclosure;

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

[0036] Figure 5 is a schematic diagram of adjustment of a fan operation scheme provided in an example embodiment of the present disclosure;

[0037] Figure 6 is a schematic diagram of the rotational speed of a fan, the total power of the fan, and the number of fans in operation, with the change of heat dissipation load provided in an example embodiment of the present disclosure.

[0038] REFERENCE SIGNS

[0039] 100, refrigeration cycle; 200, refrigerant 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, heat sink; 7, fan. DETAILED DESCRIPTION

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

[0042] The embodiment relates to an energy storage system, which is used for storing excess energy and releasing the energy at a required time or in a required area. The energy storage system is specifically an electric energy storage system, a thermal energy storage system or a kinetic energy storage system, and the embodiment does not limit the energy storage system to store which kind of energy, and the electric energy storage system is taken as an example for description.

[0043] The electric energy storage system can be a system for storing electric energy provided by at least one of commercial power, wind energy, solar energy, nuclear energy and a generator.

[0044] In application, the electric energy storage system can be applied in the fields of electric power, communication, transportation and medical treatment, and the embodiment does not limit the application scenario of the energy storage system. The energy storage system is generally arranged in an energy storage cabinet, and the energy storage cabinet can be specifically an energy storage container.

[0045] Since the energy storage cabinet is used for converting electric energy into chemical energy and storing the chemical energy in a battery, the energy storage cabinet mainly comprises the battery and related devices. Since the battery generates heat during charging and discharging, the energy storage cabinet further comprises a heat management system for heat dissipation of the battery.

[0046] The heat management system of the energy storage cabinet is generally a forced air cooling heat management system or a liquid cooling heat management system, or a combination of the forced air cooling heat management system and the liquid cooling heat management system.

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

[0048] With the demand for high energy density of the energy storage cabinet, the energy density of the current energy storage cabinet is gradually increased to 3 megawatt hours per cubic meter (MWh / m 3 , even to 5 MWh / m 3 or 6 MWh / m 3 or more. The higher the energy density of the energy storage cabinet is, the greater the heat dissipation demand is.

[0049] With the high heat dissipation demand of the energy storage cabinet, the number of compressors included in the liquid cooling heat management system of the energy storage cabinet is increased, for example, from a single compressor refrigeration to double compressor refrigeration or even more compressor refrigeration. The number of fans is also increased, for example, from three fans to more fans.

[0050] In the application of the liquid cooling heat management system to multiple compressors and / or multiple fans, the total energy consumption is also increased. How to reduce the total power consumption of the liquid cooling heat management system as much as possible on the basis of meeting the heat dissipation demand of the energy storage cabinet is a problem that technicians strive to solve.

[0051] The current liquid cooling thermal management system has energy saving optimization space on the refrigeration side, the cold carrier side and / or the cooling side. For details, refer to the following description.

[0052] As Figure 1 shows a schematic diagram of the principle of the prior art liquid cooling thermal management system, referring to Figure 1 , the liquid cooling thermal management system mainly includes three cycles, namely refrigeration cycle 100, cold carrier cycle 200 and cooling cycle 300, wherein the refrigeration cycle 100 is used to manufacture cold, the cold carrier cycle 200 is used to transmit the cold manufactured by the refrigeration cycle 100 to the battery to dissipate heat for the battery, and the cooling cycle 300 is used to discharge the heat generated by the refrigeration cycle 100 and the cold carrier cycle 200.

[0053] Referring to Figure 1 , 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 and the input end of the throttle valve 3 are connected through a pipeline, the output end of the throttle valve 3 and the input end of the evaporator 4 are connected through a pipeline, and the output end of the evaporator 4 and the input end of the compressor 1 are connected through a pipeline, so that the compressor 1, the condenser 2, the throttle valve 3 and the evaporator 4 form a refrigeration circuit of the refrigeration cycle.

[0054] Among them, the compressor 1 is the core device of the refrigeration cycle 100, which is used to compress the low-pressure gaseous refrigerant (wherein the refrigerant is also called refrigerant) into high-pressure gaseous refrigerant, the condenser 2 is used to condense the gaseous refrigerant into 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, and the evaporator 4 is used to evaporate the liquid refrigerant into gaseous refrigerant, which is circulated to the compressor

[0055] Referring to Figure 1 , the refrigeration cycle 100 includes a plurality of compressors 1 Figure 1 , of which two compressors 1 are exemplified, the plurality of 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 end of the plurality of compressors 1, the output end of the condenser 2 is connected to the output end of the plurality of compressors 1, and the plurality of compressors 1 are all on the same refrigeration circuit. Then, the gaseous refrigerant discharged from the evaporator 4 is distributed to the plurality of compressors 1, which are used to increase the pressure to manufacture cold.

[0056] From Figure 1As can be seen, although the refrigeration cycle 100 includes multiple compressors 1, only one throttling valve 3 is provided, so only one refrigeration circuit can be formed. Therefore, when the heat dissipation requirement of the liquid cooling cycle changes, the rotation speed of the compressors 1 can be adjusted as a whole.

[0057] For example, when the heat dissipation requirement of the liquid cooling cycle changes, the controller of the energy storage cabinet, such as an energy management system, adjusts the opening degree of the throttling valve 3. When the opening degree of the throttling 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 rotation speed of the compressors 1 also needs to be adjusted.

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

[0059] However, in actual applications, the total refrigerant discharged from the evaporator 4 is not equally distributed to the multiple compressors 1 due to the influence of the pipeline layout and the flow resistance of the refrigerant in the pipeline. As a result, some compressors 1 are allocated more refrigerant, and some compressors 1 are allocated less refrigerant. The actual rotation speed of the compressors 1 is affected by the refrigerant, so the actual rotation speed of the compressors 1 deviates from the design rotation speed. The design rotation speed is the optimal rotation speed calculated based on the refrigeration and energy saving strategies. If the actual rotation speed of the compressors 1 deviates from the design rotation speed, the compressors 1 are likely to operate in a mode other than the maximum efficiency and optimal operation mode, and thus the total power consumption of the compressors 1 is likely to be large.

[0060] In addition, the compressors allocated more refrigerant are likely to operate in an overload mode, and the compressors allocated less refrigerant are likely to operate in an underload mode.

[0061] The above is the case where the refrigeration cycle 100 of the liquid cooling thermal management system has a large power consumption.

[0062] Continuing to refer to Figure 1 As shown, the liquid 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 into a circulation loop through pipelines. 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 to enable heat exchange between the liquid cooling plate and the battery. Referring to Figure 1 As shown, the pipeline of the liquid cooling cycle is in contact with or connected to the evaporator 4, for example, the pipeline of the liquid cooling cycle passes through the evaporator. In this way, the refrigerant flowing through the evaporator exchanges heat with the refrigerant flowing through the liquid cooling plate 5 to absorb the cold energy near the evaporator 4.

[0063] Wherein, the liquid (generally water) flowing in the pipeline of the cooling load circulation 200 absorbs the cold energy near the evaporator, and the temperature is relatively low, so the liquid flowing in the pipeline of the cooling load circulation 200 is called chilled liquid or chilled water, the chilled liquid flowing into the liquid cooling plate 5 can be recorded as chilled supply water, and the chilled liquid flowing out of the liquid cooling plate 5 can be recorded as chilled return water.

[0064] In this way, the heat generated by the battery is absorbed by the chilled liquid in the liquid cooling plate 5, the battery is cooled, and 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 chilled supply water after cooling flows into the liquid cooling plate 5 again to dissipate heat for the battery.

[0065] Wherein, the cooling load circulation 200 is arranged with a temperature sensor near the input end of the liquid cooling plate 5 to monitor the temperature of the chilled liquid of the cooling load circulation 200, and the temperature is recorded as the chilled supply water temperature in order to distinguish from the temperature of the cooling liquid in the cooling circulation. Of course, the cooling load circulation 200 can also be arranged with a temperature sensor near the output end of the liquid cooling plate 5 to monitor the chilled return water temperature of the cooling load circulation 200.

[0066] Wherein, the refrigeration capacity of the refrigeration circulation 100 is related to the chilled supply water temperature or the chilled return water temperature of the cooling load circulation 200. For example, when the chilled supply water temperature of the cooling load circulation 200 is relatively high, such as higher than the target chilled temperature, the refrigeration capacity of the refrigeration circulation 100 will be increased. Wherein, the increase of the refrigeration capacity of the refrigeration circulation 100 is related to the opening degree of the throttling valve 3 and the rotating speed of the compressor 1.

[0067] At present, the target chilled temperature of the cooling load circulation 200 is generally a fixed value, for example, the target chilled temperature is 20 degrees, and then the operation scheme of the refrigeration circulation 100 is determined according to the difference between the chilled supply water temperature of the cooling load circulation 200 and the target chilled temperature.

[0068] In one scenario, the heat dissipation demand of the battery is relatively large, the liquid cooling plate 5 absorbs the heat of the battery, so that the chilled supply water temperature at the input end of the liquid cooling plate 5 will continue to rise, and then the difference between the chilled supply water temperature of the cooling load circulation 200 and the target chilled temperature will continue to increase. In this case, the rotating speed of the compressor will continue to increase, which is not conducive to the stable operation of the compressor, the coefficient of performance (COP) of the compressor is not high, and this case will also cause the power consumption of the liquid cooling thermal management system to be relatively large.

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

[0070] Continue to refer to 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 pipes, and the plurality of fans 7 are arranged near the radiator 6 and used for heat exchange between the radiator and air. The pipes of the cooling cycle are in contact or connected with the condenser 2, for example, the pipes where the radiator is located pass 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 fans.

[0071] As shown, the liquid (generally water) flowing in the pipes of the cooling cycle 300 is used for heat dissipation and cooling, so the water flowing in the pipes of the cooling cycle is referred to as cooling liquid, and the cooling liquid flowing into the radiator 6 is referred to as cooling supply water, and the cooling liquid flowing out of the radiator is referred to as cooling return water. Figure 1

[0072] In this way, as shown, the condenser releases heat when converting the gaseous refrigerant into the liquid refrigerant, the released heat is absorbed by the cooling return water flowing out of the radiator, the cooling supply water absorbing the heat flows into the radiator, the heat absorbed by the cooling supply water is dissipated to the environment through the fans, and the cooled cooling return water flows to the condenser again. Figure 1

[0073] However, the plurality of fans 7 included in the cooling cycle 300 are generally simultaneously turned on and turned off to quickly discharge the heat generated by the liquid cooling thermal management system to the environment, that is, all the fans of the cooling cycle are generally either simultaneously in a running state or simultaneously in a stopped state.

[0074] However, the simultaneous running of all the fans 7 of the cooling cycle 300 is easy to cause the heat dissipation to be greater than the heat dissipation demand, which leads to the total power consumption of the fans being too large, resulting in the total power consumption of the liquid cooling thermal management system being large.

[0075] The embodiment provides a liquid cooling thermal management system, and the refrigeration cycle 100 of the liquid cooling thermal management system includes a plurality of refrigeration circuits, each refrigeration circuit is independent of each other, a compressor and a throttling valve on each refrigeration circuit are independently controlled, the compressor and the throttling valve are matched one by one, the deviation between the design rotating speed and the actual rotating speed of the compressor is reduced, the precise control of the compressor is realized, the maximum power consumption and the optimal operation of the compressor are exerted, and the power consumption of the compressor is reduced.

[0076] The target freezing temperature of the cooling cycle of the liquid cooling thermal management system is a change value related to the temperature of the battery, which is beneficial to the stable operation of the compressor. The fan operation of the cooling cycle of the liquid cooling thermal management system is related to the cooling return water temperature of the cooling cycle and changes with the cooling return water temperature, which is beneficial to realizing the minimum power consumption of the fan on the basis of meeting the heat dissipation demand, so as to reduce 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] As shown in FIG. 1, it is a schematic diagram of the principle of the liquid cooling thermal management system, and as shown in FIG. 2, the liquid cooling thermal management system includes a refrigeration cycle 100, a cooling medium circulation cycle 200, and a cooling cycle 300, and the specific functions of the three are described above, which will not be repeated here. Below, first introduce the scenario of the liquid cooling thermal management system for battery cooling, and then introduce the characteristics of the refrigeration cycle 100, the cooling medium circulation cycle 200, and the cooling cycle 300 of the liquid cooling thermal management system. Figure 2 Figure 2 As shown in FIG. 1, it is a schematic diagram of the principle of the liquid cooling thermal management system, and as shown in FIG. 2, the liquid cooling thermal management system includes a refrigeration cycle 100, a cooling medium circulation cycle 200, and a cooling cycle 300, and the specific functions of the three are described above, which will not be repeated here. Below, first introduce the scenario of the liquid cooling thermal management system for battery cooling, and then introduce the characteristics of the refrigeration cycle 100, the cooling medium circulation cycle 200, and the cooling cycle 300 of the liquid cooling thermal management system.

[0079] In one example, a temperature sensor is arranged near the battery to monitor the temperature of the battery, and the controller of the energy management system (EMS) of the energy storage cabinet acquires the temperature of the battery. The controller stores a target working temperature suitable for the battery to work. When the controller detects that the temperature of the battery exceeds the target working temperature, the controller controls the liquid cooling thermal management system to start to cool the battery. When the controller detects that the temperature of the battery does not exceed the target working temperature, the controller controls the liquid cooling thermal management system to stop cooling the battery.

[0080] For example, first control the water pump in the liquid cooling thermal management system to run, then control the fan to run, and then control the compressor to run, or first control the fan to run, then control the water pump to run, and then control the compressor to run.

[0081] For example, first control the water pump in the liquid cooling thermal management system to run, then control the fan to run, and then control the compressor to run, or first control the fan to run, then control the water pump to run, and then control the compressor to run.

[0082] In one example, based on energy saving considerations, in the scenario of low ambient temperature, such as winter with low temperature, when the temperature of the battery exceeds the target working temperature by a small amount, the low-temperature environment can be used to cool the battery first, and when the temperature of the battery exceeds the target working temperature by a large amount, the liquid cooling thermal management system is started to cool the battery. Similarly, in winter with low temperature, the liquid cooling thermal management system can reduce the temperature of the battery to near the target working temperature during cooling, and the remaining temperature difference can be used to cool the battery by the low-temperature environment. Then, as shown in FIG. 3, the start and stop of the liquid cooling thermal management system can be performed according to the following steps. The execution subject can be the controller in the energy management system. Figure 3

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

[0084] ​​The ambient temperature and the temperature of the battery are obtained from temperature sensors, for example, a temperature sensor is arranged around the battery to monitor the ambient temperature around the battery, and a temperature sensor is arranged at the heat generation area of the battery to monitor the temperature of the battery.

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

[0086] For example, after obtaining the ambient temperature in step 320, the controller can determine the start-stop trigger temperature for controlling the liquid cooling thermal management system to start and stop according to the ambient temperature and the target working temperature of the battery stored in advance.

[0087] As an example, when the ambient temperature is not higher than the target working temperature, the start-stop trigger temperature can be a temperature higher than the target working temperature, and when the ambient temperature is higher than the target working temperature, the start-stop trigger temperature can be a temperature not higher than the target working temperature.

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

[0089] In step 330, after obtaining the temperature of the battery and determining the start-stop trigger temperature, the controller judges 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 performed. In step 340, the controller controls the liquid cooling thermal management system to start running to dissipate heat for the battery, and when it is detected that the temperature of the battery is not higher than the start-stop trigger temperature, step 350 is performed, in which the liquid cooling thermal management system is controlled to stop running.

[0090] For example, in a low-temperature environment, such as when the ambient temperature (e.g., 10 degrees) is lower than the target working temperature (e.g., 20 degrees), the liquid cooling thermal management system stops dissipating heat for the battery when it is detected that the temperature of the battery (e.g., 25 degrees) is still greater than the target working temperature (e.g., 20 degrees) but has reached the start-stop trigger temperature (e.g., 25 degrees), and the temperature difference between the temperature of the battery and the target working temperature allows the low-temperature environment to adjust.

[0091] In the scenario of low ambient temperature, if the controller detects that the temperature of the battery (e.g., 23 degrees) exceeds the target working temperature (e.g., 20 degrees) but has not exceeded the start-stop trigger temperature (e.g., 25 degrees), the controller will not control the liquid cooling thermal management system to dissipate heat for the battery, and the temperature difference between the temperature of the battery and the target working temperature will be adjusted by the low temperature environment.

[0092] For example, in the scenario of high ambient temperature, if the ambient temperature (e.g., 35 degrees) is higher than the target working temperature (e.g., 20 degrees), the start-stop trigger temperature for the controller to control the start-stop of the liquid cooling thermal management system can be the target working temperature, or a temperature value lower than the target working temperature.

[0093] This way of dissipating heat for the battery by the liquid cooling thermal management system and the ambient temperature is conducive to reducing the total power consumption of the liquid cooling thermal management system.

[0094] In an example, to avoid frequent start and stop of the liquid cooling thermal management system, the controller can control the liquid cooling thermal management system to start when it is detected that the temperature of the battery is higher than the start-stop trigger temperature for a preset time period, and to stop when it is detected that the temperature of the battery is lower than the start-stop trigger temperature for a preset time period.

[0095] This way of controlling the start-stop of the liquid cooling thermal management system is conducive to stable operation of the liquid cooling thermal management system, which is conducive to prolonging the service life of the components in the liquid cooling thermal management system and reducing the total power consumption of the liquid cooling thermal management system.

[0096] The above is the introduction of the start-stop scenario of the liquid cooling thermal management system, and the features of the refrigeration cycle, the chilled water circulation and the cooling cycle will be introduced respectively.

[0097] (1) Features of the refrigeration cycle 100.

[0098] Referring to Figure 2 As shown in the figure, 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 is multiple and equal, and 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] Referring toFigure 2 As shown, the input end of each compressor 1 is connected with one output end of the evaporator 4 through a pipe, and the output end of each compressor 1 is connected with one input end of the condenser 2 through a pipe. It is pointed out that different output ends of the evaporator 4 are connected with different compressors 1, and different input ends of the condenser 2 are connected with different compressors 1. It can also be understood that the compressors 1 and the output ends of the evaporator 4 are one-to-one connected, and the compressors 1 and the input ends of the condenser 2 are one-to-one connected.

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

[0101] Continuing to refer to Figure 2 As shown, the compressors 1 and the throttle valves 3 correspond to each other, each compressor 1 and one 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 in parallel with each other.

[0102] Referring to Figure 2 As shown, a refrigeration circuit (denoted as a 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 (denoted as a 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 by the first throttle valve 3a is all compressed by the first compressor 1a, and the refrigerant discharged by the second throttle valve 3b is all compressed by the second compressor 1b. In this way, the refrigerant discharged by the evaporator 4 does not exist in the free distribution, so that the rotation speed of the first compressor 1a and the opening degree of the first throttle valve 3a can be accurately matched, and the rotation speed of the second compressor 1b and the opening degree of the second throttle valve 3b can be accurately matched.

[0103] For example, when the controller calculates the rotation speed of the first compressor, it is based on the case that all the refrigerant discharged by the first throttle valve 3 is discharged to the first throttle valve 3a. In fact, almost all the refrigerant discharged by the first throttle valve 3a is discharged to the first throttle valve 3a. Therefore, the design rotation speed of the first compressor is close to the actual rotation speed. Then, the first compressor can work in the optimal operation mode to improve the coefficient of performance (COP) of the first compressor and reduce 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 also be reduced.

[0104] Moreover, in the scheme as shown in Figure 2 the refrigeration circuits are independent of each other. Therefore, the opening degree of the throttle valve is only affected by the rotation speed of the compressor in the refrigeration circuit, and is not affected by the rotation speed of the compressor in other refrigeration circuits. The rotation speed of the compressor is only affected by the opening degree of the throttle valve in the refrigeration circuit, and is not affected by the opening degree of the throttle valve in other refrigeration circuits. In this way, the adjustment of the compressor operation scheme of the refrigeration cycle is more flexible.

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

[0106] It should be noted that the opening degrees of the throttle valves 3 in different refrigeration circuits can be equal or not equal. The rotation speeds of the compressors in different refrigeration circuits can be equal or not equal.

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

[0108] Since the refrigeration cycle 100 generates cooling capacity for battery heat dissipation, the compressor operation scheme 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 working temperature.

[0109] Since the cooling capacity generated by the refrigeration cycle 100 is carried to the battery by the liquid cooling cycle 200 to dissipate heat for the battery, and the heat transfer between the liquid cooling plate of the liquid cooling cycle 200 and the battery needs time, the temperature of the liquid cooling plate is very low, but the temperature of the battery is still relatively high. If the compressor operation scheme is determined according to the temperature of the battery, it is easy to appear the situation of oversupply.

[0110] Therefore, the compressor operation scheme can be determined according to the relationship between the temperature of the refrigerant liquid of the liquid cooling cycle 200 (such as the temperature of the refrigerant supply water) and the target refrigeration temperature. For example, if the temperature of the refrigerant supply water is lower than the target refrigeration temperature, and the temperature difference exceeds the preset range, indicating that the temperature of the refrigerant supply water is much lower than the target refrigeration temperature, the compressor operation scheme can be that the compressor is suspended or the number of operating units of the compressor is reduced and / or the speed of the compressor is reduced. If the temperature of the refrigerant supply water is lower than the target refrigeration temperature, and the temperature difference is within the preset range, indicating that the temperature of the refrigerant supply water is slightly lower than the target refrigeration temperature, the compressor operation scheme can be to continue according to the existing scheme, or the speed of the compressor can also be reduced. If the temperature of the refrigerant supply water is higher than the target refrigeration temperature, and the temperature difference exceeds the preset range, indicating that the temperature of the refrigerant supply water is much higher than the target refrigeration temperature, the compressor operation scheme can be to increase the speed of the compressor or increase the number of operating units of the compressor. If the temperature of the refrigerant supply water is higher than the target refrigeration temperature, and the temperature difference is within the preset range, indicating that the temperature of the refrigerant supply water is slightly higher than the target refrigeration temperature, the compressor operation scheme can be to continue according to the existing scheme, or the speed of the compressor can also be increased.

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

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

[0113] It should be noted that the total power consumption of the compressor is affected by the environmental temperature, water temperature and system load rate, etc. Therefore, these factors need to be considered when calculating the total power consumption of the compressor.

[0114] It should be noted that the above determination strategy of the compressor operation scheme can be applied to the refrigeration cycle as shown in Figure 2 and can also be applied to the refrigeration cycle as shown in Figure 1In the refrigeration cycle shown, that is, the strategy for formulating the compressor operation plan is not limited to applications such as... Figure 2 In the refrigeration cycle shown.

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

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

[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, water pump and water tank are connected in series through pipes. The water pump is used to pump the coolant in the water tank into the liquid cooling plate, so that the coolant circulates in the pipes.

[0118] As mentioned above, the compressor operation plan is mainly determined by the relationship between the water temperature of the cooling cycle 200 and the target water temperature. The water temperature can be either the chilled water supply temperature or the chilled water return temperature. For ease of explanation, the following example uses the chilled water supply temperature as the water temperature and the target water temperature as the target chilled temperature. In this embodiment, the target chilled temperature is a variable value; for example, it could be a variable value related to the battery temperature.

[0119] For example, if the target freezing temperature of the cooling cycle is positively correlated with the battery temperature, then as the battery temperature continues to rise, the target freezing temperature will also rise. This prevents the difference between the chilled water supply temperature of the cooling cycle and the target freezing temperature from increasing sharply or continuously. Consequently, the compressor is less likely to experience a sharp increase in speed or a continuous increase in speed during operation, allowing the compressor to operate in a relatively stable state. The cooling cycle smoothly dissipates heat from the battery, which improves the compressor's cooling efficiency and also helps protect the compressor.

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

[0121] When the target freezing temperature is variable, the compressor operation plan can be determined as follows.

[0122] Firstly, the controller needs to acquire the temperature of the battery and the chilled supply water temperature flowing into the liquid cooling plate. Then, according to the temperature of the battery and the chilled supply water temperature, the number of operating compressors and the rotating speed of the compressors, and the number of opening the throttling valves and the opening degree of the throttling valves are determined. For example, after the controller acquires the temperature of the battery, the target chilled temperature can be determined according to the temperature of the battery, and then the operating scheme of the compressor and the opening scheme of the throttling valve are determined according to the relationship between the chilled supply water temperature and the target chilled temperature. For details, reference can be made to the above description, which will not be repeated here.

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

[0124] (III) Features of the cooling cycle 300.

[0125] Referring to Figure 2 As shown, the cooling cycle 300 includes the heat sinks 6, the fans 7 and the water pump. Unlike the prior art in which multiple fans 7 are started and stopped at the same time, the operating scheme of the fans in the cooling cycle 300 in the embodiment is related to the cooling return water temperature of the cooling cycle 300. The operating scheme of the fans includes at least one of the number of operating fans and the rotating speed of the fans. The cooling return water temperature can refer to Figure 4 As shown, it is the temperature of the cooling liquid on the dry way connected to the output ports of all the heat sinks 6. A temperature sensor can be arranged at the junction of the output ports of all the heat sinks 6 to monitor the cooling return water temperature of the cooling cycle 300.

[0126] In one example, the controller can acquire the cooling return water temperature of the cooling cycle when the cooling cycle is in the operating state. When the temperature difference between the cooling return water temperature and the target cooling temperature is not within the pre-stored temperature range, the operating scheme of the fans of the cooling cycle 300 is adjusted.

[0127] The adjustment of the operating scheme of the fans can be the adjustment of the rotating speed of the fans, the adjustment of the number of operating fans, or the adjustment of the rotating speed of the fans and the number of operating fans. Referring to Figure 4 As shown, the controller has an electrical connection relationship with all the fans to control the fans.

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

[0129] The speed limit values ​​include an upper speed limit and a lower speed limit, where the lower speed limit is the minimum speed f required for the fan to operate. min The upper limit of the rotational speed is the maximum rotational speed f that the fan can operate at. max Or, the upper limit of the rotational speed is less than f. max Target speed f set Among them, the target rotational speed f set It can be a set rotation speed (such as a value determined based on empirical values ​​or in a pre-trained model, as described later).

[0130] Continue to refer to Figure 5 As shown, in step 540, the controller adjusts the number of operating fans. This adjustment can be done one fan at a time, such as increasing or decreasing the number of fans one by one. Alternatively, multiple fans can be added or removed simultaneously. The one-fan-at-a-time adjustment is more suitable for scenarios where the cooling return water temperature changes gradually, while the simultaneous adjustment of multiple fans is more suitable for scenarios where the cooling return water temperature changes rapidly. Those skilled in the art can flexibly choose the appropriate fan adjustment method based on the actual scenario; this embodiment does not limit this choice.

[0131] Continue to refer to Figure 5 As shown, after the controller adjusts the number of operating fans, it proceeds to step 550. In step 550, after adjusting the number of operating fans, it determines whether the temperature difference between the cooling return water temperature and the target cooling temperature is within the preset temperature range. If it is, it proceeds to stop adjusting the fan operation plan. However, if after adjusting the number of fans, the temperature difference between the cooling return water temperature and the target cooling temperature is still not within the temperature range (e.g., due to insufficient adjustment or over-adjustment), it proceeds 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 such Figure 5The flow chart shows examples of reducing the number of operating fans and increasing the number of operating fans, respectively.

[0133] For example, 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, and then controls the fan to reduce the speed. During the reduction of the fan speed, the temperature difference is monitored. If the temperature difference is detected to be within the set temperature range, the reduction of the fan speed is stopped, and the fan is operated at the current speed.

[0134] If the fan speed is detected to have been reduced to the lower limit of the speed, 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 operating fans to stop operating, thereby reducing the number of operating fans.

[0135] The fan operating after the reduction operates at the lower limit of the speed. 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, one more fan is reduced. If the temperature difference is within the set temperature range after the reduction, the speed of the fan after the reduction is the lower limit of the speed. If the temperature difference exceeds the set temperature range after the reduction, the speed of the fan is increased until the temperature difference is within the temperature range.

[0136] For example, 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, and then controls the fan to increase the speed. During the increase of the fan speed, the temperature difference is monitored. If the temperature difference is detected to be within the set temperature range, the increase of the fan speed is stopped, and the fan is operated at the current speed.

[0137] If the fan speed is detected to have been increased to the upper limit of the speed, but the temperature difference between the cooling return water temperature and the target cooling temperature is still higher than the temperature range, the controller controls one of the non-operating fans to start operating, thereby increasing the number of operating fans. The fan operating after the increase operates at the upper limit of the speed. 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, one more fan is added. If the temperature difference is within the set temperature range after the increase, the speed of the fan after the increase is the upper limit of the speed. If the temperature difference is lower than the set temperature range after the increase, the speed of the fan is reduced until the temperature difference is within the temperature range.

[0138] It should be noted that the multiple fans are in operation, and the rotation speed of the multiple fans is generally equal. Of course, the controller can also control the rotation speed of each fan individually. However, whether the rotation speed of the fan is equal or not, the rotation speed of each fan needs to consider not only the relationship between the temperature difference between the cooling return water temperature and the target cooling temperature and the target cooling temperature, and the total power consumption of the fan, but also whether the generated noise meets the noise index requirement, and even environmental factors such as environmental temperature and environmental humidity.

[0139] It should be noted that the above process is the adjustment strategy of the fan operation scheme during the operation of at least one fan in the cooling cycle. As for the number of fans started when the cooling cycle is just started to operate and the rotation speed of the fan, the present embodiment does not limit it. For example, the number of fans and the rotation speed can be controlled according to historical data, or the number of fans and the rotation speed can be calculated according to the principle of the lowest total power consumption of the fan according to the relationship between the temperature difference between the cooling return water temperature and the target cooling temperature and the target temperature range.

[0140] In an example, the total power of the fan also changes during the adjustment of the fan operation scheme, for example, as shown in Figure 6 , which is a schematic diagram of the change of each data in the cooling cycle. In Figure 6 , the heat dissipation load represents the heat that needs to be cooled by the cooling cycle, and is related to the relationship between the temperature difference between the cooling return water temperature and the target cooling temperature and the set temperature range. Figure 6 In , N represents the number of fans in operation.

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

[0142] Referring to Figure 6 , when the heat dissipation load curve is constant, the rotation speed f of the fan is constant, and the total power consumption of the fan is also constant. When the heat dissipation load becomes larger, the rotation speed f of the fan is first increased, and the total power of the fan is also increased. When the rotation speed is increased to the upper limit value, the heat dissipation load curve is not reduced or not reduced to an appropriate range, and then one more fan is added. After the fan is added, the rotation speed is reduced (by how much, depending on the size of the heat dissipation load), so the total power of the fan decreases.

[0143] Continuing to refer to Figure 6As shown, when the heat dissipation load decreases, the speed of the fan first decreases, and the total power of the fan also decreases. When the speed decreases to the lower limit of the speed, the heat dissipation load is still relatively small, so one fan can be reduced, and the number of fans is reduced. At this moment, all the fans are running at the lower limit of the speed, so the total power of the fan will decrease. After the reduction, the speed is adjusted upward (how much to adjust depends on the size of the heat dissipation load), so the total power of the fan will increase.

[0144] It should be noted that, Figure 6 The curves in the figures are only examples and do not limit the embodiments. Reference is made to Figure 6 As shown, the change time of the speed of the fan lags behind the change time of the heat dissipation load, because there is a certain delay. When the heat dissipation load is relatively small, the speed of the fan is relatively low, and the total power of the fan is relatively low. When the heat dissipation load is relatively large, the speed of the fan is relatively high, and the total power of the fan is relatively high. 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 change of the speed of the fan, and then controls the change of the number of fans. The size of the heat dissipation load before and after the change of the heat dissipation load curve is not shown in the figure. Figure 6

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

[0146] As described above, the upper limit of the speed of the fan can be the maximum speed that the fan can reach in the running state, which is the attribute of the fan. The upper limit of the speed can also be set according to experience, for example, it can be 90% of the maximum speed f max that the fan can reach in the running state. The upper limit of the speed can also be determined according to an artificial intelligence (AI) model. For example, the upper limit of the speed is determined by a pre-trained fan speed model. The training process of the fan speed model can be referred to as follows.

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

[0148] ​Then, the input sample is input into the initial fan rotating speed model to obtain a tested rotating speed upper limit value. After that, the rotating speed upper limit value in the corresponding output sample and the tested rotating speed upper limit value are input into a loss function to obtain a loss value, and then the initial fan rotating speed model is adjusted using the loss value. In this way, after multiple rounds of training, the fan rotating speed model can be obtained.

[0149] Therefore, in the application, the number of running fans, the fan rotating speed, the 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 rotating speed model to obtain the rotating speed upper limit value.

[0150] It should be noted that after determining the rotating speed upper limit value by the fan rotating speed model, the rotating speed upper limit value can also be adjusted according to the specific application scenario of the liquid cooling thermal management system, for example, according to one or more parameters such as the noise index requirement, the power-rotating speed curve of the fan, and the air volume-rotating speed curve of the fan.

[0151] It should be noted that in the fan operation scheme adjustment, the temperature difference between the cooling return water temperature and the target cooling temperature is satisfied, and the total power consumption of the fan is minimized within the set temperature range.

[0152] In the embodiments of the present disclosure, the refrigeration cycle of the liquid cooling thermal management system not only includes multiple compressors but also includes multiple throttling valves to form multiple parallel refrigeration circuits. The refrigerant discharged from each refrigeration circuit is almost entirely distributed to the compressors on the refrigeration circuit, so that the theoretical value and the actual value of the refrigerant distributed to the compressors are close, and then the design rotating speed and the actual rotating speed of the compressors are also close, thereby improving the control accuracy of the compressors, enabling the compressors to operate at a better energy efficiency, and being conducive to reducing the power consumption of the compressors and further reducing the power consumption of the liquid cooling thermal management system.

[0153] In the embodiments of the present disclosure, the number of running compressors and the rotating speed of the compressors, and the number of open throttling valves and the opening degree of the throttling valves are not only related to the temperature of the refrigerant flowing into the liquid cooling plate but also related to the temperature of the battery, which is conducive to stable operation of the compressors, reduction of the power consumption of the compressors, protection of the compressors, and prolongation of the service life of the compressors.

[0154] Specifically, the target refrigeration temperature required by the refrigerant flowing into the liquid cooling plate changes with the temperature of the battery, for example, when the temperature of the battery rises, the target refrigeration temperature also rises, so that the temperature difference between the temperature of the refrigerant flowing into the liquid cooling plate and the target refrigeration temperature is relatively stable (e.g., changes stably), and the number of running compressors and the rotating speed of the compressors are related to the temperature difference between the temperature of the refrigerant and the target refrigeration temperature, so that the temperature difference is stable and the operation of the compressors is also stable.

[0155] In the embodiments of the present disclosure, the multiple fans of the cooling circulation of the cold night heat dissipation system are not started and stopped at the same time, but are adjusted in the number of running fans and the rotating speed of the fans according to the temperature difference between the cooling return water temperature and the target cooling temperature, the relationship between the temperature difference and the set temperature range, and the total power consumption of the fans. In this way, the total power consumption of the fans is minimized under the requirement of meeting the heat dissipation demand, which is beneficial 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 embodiments of the present disclosure, the start and stop of the liquid cooling thermal management system are not determined only according to the relationship between the temperature of the battery and the target working temperature, but are determined according to the environmental temperature, the temperature of the battery and the target working temperature. For example, in the scenario of low environmental temperature, the liquid cooling thermal management system stops running after reducing the temperature of the battery to slightly higher than the target working temperature, and the small temperature difference between the temperature of the battery and the target working temperature can be adjusted by the low-temperature environment. In this way, the total power consumption of the liquid cooling thermal management system is reduced, and energy-saving control of the liquid cooling thermal management system is realized.

[0157] The present embodiment also provides a storage cabinet, which includes a cabinet body and multiple batteries and the above-mentioned liquid cooling thermal management system in the cabinet body. The batteries serve as the core of the storage cabinet for storing and releasing electric energy, and the liquid cooling thermal management system is used to dissipate heat for the storage cabinet, for example, for the multiple batteries in the storage cabinet.

[0158] Of course, the cabinet body of the 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 state of the battery to ensure that the charging and discharging of the battery are balanced, and the energy management system is used to monitor, manage and optimize the operation of the energy storage system, for example, by collecting, analyzing and optimizing energy data in real time to ensure stable and efficient operation of the storage cabinet, while improving energy utilization efficiency and reducing operating costs.

[0159] The above-mentioned only for optional embodiments of the present disclosure, and does not limit the present disclosure, any modification, equivalent replacement, improvement, etc. made within the principles of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A liquid-cooled thermal management system, characterized by, The liquid cooling thermal management system comprises a plurality of compressors (1), a condenser (2), a plurality of throttling 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) in the plurality of compressors is connected by a pipeline between one input end of the condenser (2) and one output end of the evaporator (4), each throttling valve (3) in the plurality of throttling valves is connected by a pipeline between one output end of the condenser (2) and one input end of the evaporator (4), 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 for heat exchange between the refrigerant flowing through the evaporator and the refrigerant flowing through the liquid cooling plate; The liquid cooling plate is used for heat exchange with the battery to dissipate heat for the battery, the radiator (6) is used for heat exchange between the refrigerant flowing through the condenser (2) and the cooling liquid flowing through the radiator, and the plurality of fans (7) are used for heat exchange between the cooling liquid flowing through the radiator (6) and the air in the environment; The controller is used for adjusting the number and rotating speed of the running compressors (1) in the plurality of compressors (1) and adjusting the number and opening degree of the opened throttling valves (3) in the plurality of throttling valves (3) according to the temperature of the battery and the temperature of the refrigerant flowing into the liquid cooling plate (5), so as to reduce the power consumption of the liquid cooling thermal management system under the condition of meeting the heat dissipation demand.

2. The liquid cold thermal management system of claim 1, wherein, The controller is used for adjusting the number and rotating speed of the running compressors (1) in the plurality of compressors (1) and adjusting the number and opening degree of the opened throttling valves (3) in the plurality of throttling 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 plurality of running compressors (1), so as to reduce the power consumption of the liquid cooling thermal management system under the condition of meeting the heat dissipation demand.

3. The liquid cold thermal management system of claim 2, wherein, The controller is specifically used for: determining a target refrigeration temperature according to the temperature of the battery; adjusting the number and rotating speed of the running compressors (1) in the plurality of compressors (1) and adjusting the number and opening degree of the opened throttling valves (3) in the plurality of throttling valves (3) according to that the temperature of the refrigerant flowing into the liquid cooling plate (5) is not greater than the target refrigeration temperature and the sum of the power consumptions of each compressor (1) in the plurality of running compressors (1) is the lowest, so as to reduce the power consumption of the liquid cooling thermal management system under the condition of meeting the heat dissipation demand.

4. The liquid cold thermal management system of claim 1, wherein, The controller is further configured to adjust the rotation speed of the running fans (7) in the plurality of fans (7) and / or adjust the number of the running fans (7) in the plurality of fans (7) according to the temperature of the cooling liquid flowing out of the radiator (6) and the pre-stored target cooling temperature, so as to reduce the power consumption of the liquid cooling thermal management system while meeting the heat dissipation requirement.

5. The liquid cold thermal management system of claim 4, wherein, The controller is specifically configured to adjust the rotation speed of the running fans (7) in the plurality of fans (7) according to the temperature difference between the temperature of the cooling liquid flowing out of the radiator (6) and the pre-stored target cooling temperature, so as to reduce the power consumption of the liquid cooling thermal management system while meeting the heat dissipation requirement, if the temperature difference is not within a pre-stored temperature range. If the rotation speed of the running fans (7) in the plurality of fans (7) is adjusted to a rotation speed limit value, and the temperature difference between the temperature of the cooling liquid flowing out of the radiator (6) and the target cooling temperature is not within a set temperature range, the number of the running fans is adjusted, so as to reduce the power consumption of the liquid cooling thermal management system while meeting the heat dissipation requirement.

6. The liquid cold thermal management system of claim 5, wherein, The controller is specifically configured to increase or decrease the number of the running fans, so as to reduce the power consumption of the liquid cooling thermal management system while meeting the heat dissipation requirement, if the rotation speed of the running fans (7) in the plurality of fans (7) is adjusted to a rotation speed limit value, and the temperature difference between the temperature of the cooling liquid flowing out of the radiator (6) and the pre-stored target cooling temperature is not within a set temperature range. If the temperature difference between the temperature of the cooling liquid flowing out of the radiator (6) and the pre-stored target cooling temperature is not within the set temperature range after adjusting the number of the running fans, the rotation speed of the running fans (7) in the plurality of fans (7) is adjusted, so as to reduce the power consumption of the liquid cooling thermal management system while meeting the heat dissipation requirement.

7. The liquid cold thermal management system of claim 5, wherein, The rotation speed limit value includes a rotation speed lower limit value and a rotation speed upper limit value, wherein the rotation speed lower limit value is the minimum rotation speed of the running fans, and the rotation speed upper limit value is the maximum rotation speed of the running fans or a set rotation speed less than the maximum rotation speed of the running fans.

8. The liquid cold thermal management system of claim 4, wherein, The controller is further configured to adjust the rotation speed of the running fans in the plurality of fans and / or adjust the number of the running fans in the plurality of fans according to the temperature of the cooling liquid flowing out of the radiator (6), the pre-stored target cooling temperature, and the noise of the running fans in the plurality of fans, so as to reduce the power consumption of the liquid cooling thermal management system while meeting the heat dissipation requirement.

9. The liquid cold thermal management system of any one of claims 4 to 8, wherein, The rotation speed of each of the running fans in the plurality of fans is the same.

10. An energy storage cabinet characterized by, The energy storage cabinet includes a box body, and a plurality of batteries and the liquid cooling thermal management system of any one of claims 1 to 9 in the box body. The liquid cooling thermal management system is used for dissipating heat for the energy storage cabinet.

Images