Energy storage battery thermal management system

Abstract

The present application proposes a thermal management system for energy storage batteries, which belongs to the technical field of thermal management of energy storage batteries. The system includes a compressor, a first multi-way valve, a valve assembly, an outdoor heat exchanger, a regenerator, a main electronic expansion valve, a liquid storage tank, a diverter, at least one branch electronic expansion valve and at least one battery cold plate, wherein each branch where the battery cold plate is located is equipped with a corresponding branch electronic expansion valve, and each battery cold plate is in contact with an energy storage battery. Through this system, a refrigeration cycle can be formed to cool the energy storage battery when the energy storage battery needs to be cooled, and a heating cycle can be formed to heat the energy storage battery when the energy storage battery needs to be heated, thereby avoiding the operating temperature of the energy storage battery being too high or too low, thereby improving the charging and discharging efficiency of the energy storage battery. It also has reliable performance and low cost.

Description

Technical Field

[0001] The present application relates to the technical field of thermal management of energy storage batteries, and in particular to a thermal management system for energy storage batteries. Background Art

[0002] The charging and discharging efficiency of energy storage batteries is greatly affected by the ambient temperature. Only within a certain temperature range can the charging and discharging efficiency of energy storage batteries be the highest. At colder or hotter ambient temperatures, the charging and discharging efficiency of energy storage batteries is low, which seriously affects the service life and performance of the energy storage batteries.

[0003] In the existing technology, most energy storage battery thermal management systems use liquid cooling or air cooling solutions. The air cooling solution uses an air conditioner to blow cold or hot air through the air duct to the battery pack to achieve battery temperature control. This solution is complex in structure and has poor temperature uniformity. The liquid cooling solution uses an air conditioning unit to first cool or heat the coolant, generally an ethylene glycol solution, which then exchanges heat with the battery through the battery cold plate to achieve battery temperature control. This solution has better temperature uniformity, but is costly. After the secondary heat exchange, the system suffers from heat exchange losses and the heat exchange response time becomes longer. Summary of the Invention

[0004] The main purpose of the embodiments of the present application is to propose a thermal management system for energy storage batteries, which aims to use refrigerant to directly cool or heat energy storage batteries, reasonably control the temperature of the refrigerant entering the battery cold plate, and has reliable performance and low cost.

[0005] To achieve the above objectives, the present application provides an energy storage battery thermal management system, comprising a compressor, a first multi-way valve, a valve assembly, an outdoor heat exchanger, a regenerator, a main electronic expansion valve, a liquid storage tank, a flow divider, at least one branch electronic expansion valve, and at least one battery cold plate. Each branch where the battery cold plate is located is equipped with a corresponding branch electronic expansion valve, and each battery cold plate is in contact with an energy storage battery.

[0006] The first end of the compressor is in communication with the first end of the first multi-way valve, the second end of the first multi-way valve is in communication with the first end of the valve assembly, and the third end of the first multi-way valve is also in communication with the first end of the regenerator;

[0007] The second end of the valve assembly is in communication with the first end of the outdoor heat exchanger, the second end of the outdoor heat exchanger is in communication with the second end of the regenerator, the third end of the regenerator is in communication with the third end of the valve assembly, and the fourth end of the valve assembly is also in communication with the first end of the main electronic expansion valve;

[0008] The second end of the main electronic expansion valve is communicated with the first end of the liquid storage tank, the second end of the liquid storage tank is communicated with the first end of the diverter, the second end of the diverter is communicated with the first end of at least one branch electronic expansion valve, the second end of at least one branch electronic expansion valve is communicated with the first end of the battery cold plate on the corresponding branch, and the second end of the battery cold plate is communicated with the fourth end of the regenerator.

[0009] In one embodiment of the present application, the system further comprises a filter;

[0010] A filter is provided between the fourth end of the valve assembly and the first end of the main electronic expansion valve, and a filter is provided between the second end of the main electronic expansion valve and the first end of the liquid storage tank;

[0011] and / or,

[0012] A filter is provided between the second end of the liquid storage tank and the first end of at least one branch electronic expansion valve, and a filter is provided between the second end of at least one branch electronic expansion valve and the first end of the battery cold plate on the corresponding branch.

[0013] In one embodiment of the present application, the system includes a refrigeration cycle loop, which includes the compressor, the first multi-way valve, the valve assembly, the outdoor heat exchanger, the regenerator, the valve assembly, the main electronic expansion valve, the liquid storage tank, the diverter, the at least one branch electronic expansion valve, the at least one battery cold plate, the regenerator and the compressor, which are connected in sequence to form a loop.

[0014] In one embodiment of the present application, the system also includes a heating circulation loop, which includes the compressor, the first multi-way valve, the regenerator, the at least one battery cold plate, the at least one branch electronic expansion valve, the diverter, the liquid storage tank, the main electronic expansion valve, the valve assembly, the outdoor heat exchanger, the regenerator, the valve assembly, the first multi-way valve and the compressor, which are connected in sequence to form a loop.

[0015] In one embodiment of the present application, the valve assembly includes a first one-way valve, a second one-way valve, a third one-way valve, and a fourth one-way valve;

[0016] The output end of the first one-way valve is communicated with the input end of the second one-way valve, the input end of the second one-way valve is also communicated with the second end of the first multi-way valve, and the output end of the second one-way valve is communicated with the first end of the outdoor heat exchanger;

[0017] The input end of the first one-way valve is connected to the third end of the regenerator, the input end of the fourth one-way valve is connected to the third end of the regenerator, the output end of the fourth one-way valve is connected to the input end of the third one-way valve, the output end of the fourth one-way valve is also connected to the first end of the main electronic expansion valve, and the output end of the third one-way valve is connected to the first end of the outdoor heat exchanger.

[0018] In one embodiment of the present application, the system further includes a controller, and the first one-way valve, the second one-way valve, the third one-way valve, and the fourth one-way valve are all electrically connected to the controller, and the controller is configured to:

[0019] When the energy storage battery needs to be cooled, the second one-way valve and the fourth one-way valve are controlled to be connected, and the first one-way valve and the third one-way valve are controlled to be disconnected, so that the compressor, the first multi-way valve, the second one-way valve, the outdoor heat exchanger, the regenerator, the fourth one-way valve, the main electronic expansion valve, the liquid storage tank, the flow divider, the at least one branch electronic expansion valve, the at least one battery cold plate, the regenerator, and the compressor are connected in sequence to form the refrigeration cycle to cool the energy storage battery;

[0020] When the energy storage battery needs to be heated, the second one-way valve and the fourth one-way valve are controlled to be disconnected, and the first one-way valve and the third one-way valve are controlled to be connected, so that the compressor, the first multi-way valve, the regenerator, the at least one battery cold plate, the at least one branch electronic expansion valve, the diverter, the liquid storage tank, the main electronic expansion valve, the third one-way valve, the outdoor heat exchanger, the regenerator, the first one-way valve, the first multi-way valve and the compressor are connected in sequence to form the heating cycle to heat the energy storage battery.

[0021] In one embodiment of the present application, the valve assembly includes a second multi-way valve, the second multi-way valve including a first port, a second port, a third port, and a fourth port;

[0022] The first port is in communication with the second end of the first multi-way valve, and the second port is in communication with the first end of the outdoor heat exchanger;

[0023] The third port is communicated with the third end of the regenerator, and the fourth port is communicated with the first end of the main electronic expansion valve.

[0024] In one embodiment of the present application, the system further includes a controller, the second multi-way valve is electrically connected to the controller, and the controller is configured to:

[0025] When the energy storage battery needs to be cooled, the first port is controlled to be connected to the second port, and the third port is controlled to be connected to the fourth port, so that the compressor, the first multi-way valve, the first port, the second port, the outdoor heat exchanger, the regenerator, the third port, the fourth port, the main electronic expansion valve, the liquid storage tank, the flow divider, the at least one branch electronic expansion valve, the at least one battery cold plate, the regenerator, and the compressor are connected in sequence to form the refrigeration cycle to cool the energy storage battery;

[0026] When the energy storage battery needs to be heated, the fourth port is controlled to be connected to the second port, and the third port is controlled to be connected to the first port, so that the compressor, the first multi-way valve, the regenerator, the at least one battery cold plate, the at least one branch electronic expansion valve, the diverter, the liquid storage tank, the main electronic expansion valve, the fourth port, the second port, the outdoor heat exchanger, the regenerator, the third port, the first port, the first multi-way valve and the compressor are connected in sequence to form the heating cycle to heat the energy storage battery.

[0027] In one embodiment of the present application, the system further includes a pressure sensor, a first temperature sensor, and a controller. The pressure sensor is disposed between the first end of the compressor and the first end of the first multi-way valve, and is used to collect the exhaust pressure of the compressor; the first temperature sensor is disposed at the first end of the compressor, and is used to collect the exhaust temperature of the compressor;

[0028] The main electronic expansion valve, the pressure sensor, and the first temperature sensor are all electrically connected to the controller, and the controller is further configured to:

[0029] acquiring the exhaust pressure of the compressor acquired by the pressure sensor and the exhaust temperature of the compressor acquired by the first temperature sensor, and calculating the exhaust superheat of the compressor based on the exhaust pressure and the exhaust temperature of the compressor;

[0030] comparing the exhaust superheat of the compressor with a first preset value;

[0031] When the exhaust superheat of the compressor is greater than the first preset value, controlling to increase the opening of the total electronic expansion valve;

[0032] When the exhaust superheat of the compressor is less than the first preset value, controlling to reduce the opening of the total electronic expansion valve;

[0033] When the exhaust gas superheat of the compressor is equal to the first preset value, the opening of the total electronic expansion valve is controlled to remain unchanged.

[0034] In one embodiment of the present application, the system further includes a second temperature sensor, a third temperature sensor, and a controller. The second temperature sensor is disposed between the second end of at least one branch electronic expansion valve and the first end of the battery cold plate on the corresponding branch, and is used to collect the inlet temperature of the battery cold plate. The third temperature sensor is disposed between the second end of the battery cold plate and the fourth end of the regenerator, and is used to collect the outlet temperature of the battery cold plate.

[0035] The at least one branch electronic expansion valve, the second temperature sensor, and the third temperature sensor are all electrically connected to the controller, and the controller is configured as follows:

[0036] When the energy storage battery needs to be cooled, obtaining the inlet temperature of the battery cold plate acquired by the second temperature sensor and the outlet temperature of the battery cold plate acquired by the third temperature sensor, and calculating the superheat of the battery cold plate based on the inlet temperature and the outlet temperature of the battery cold plate;

[0037] comparing the overheat degree of the battery cold plate with a second preset value;

[0038] When the overheat degree of the battery cold plate is greater than the second preset value, controlling to increase the opening degree of the branch electronic expansion valve on the corresponding branch;

[0039] When the overheat degree of the battery cold plate is less than the second preset value, controlling to reduce the opening degree of the branch electronic expansion valve on the corresponding branch;

[0040] When the superheat degree of the battery cold plate is equal to the second preset value, the opening degree of the branch electronic expansion valve on the corresponding branch is controlled to remain unchanged.

[0041] In the technical solution provided in the embodiment of the present application, a thermal management system for an energy storage battery is proposed, including a compressor, a first multi-way valve, a valve assembly, an outdoor heat exchanger, a regenerator, a main electronic expansion valve, a liquid storage tank, a diverter, at least one branch electronic expansion valve and at least one battery cold plate, wherein each branch where the battery cold plate is located is correspondingly equipped with a branch electronic expansion valve, and each battery cold plate is in contact with an energy storage battery. The first end of the compressor is connected to the first end of the first multi-way valve, the second end of the first multi-way valve is connected to the first end of the valve assembly, and the third end of the first multi-way valve is also connected to the first end of the regenerator. The second end of the valve assembly is connected to the first end of the outdoor heat exchanger, the second end of the outdoor heat exchanger is connected to the second end of the regenerator, the third end of the regenerator is connected to the third end of the valve assembly, and the fourth end of the valve assembly is also connected to the first end of the main electronic expansion valve. The second end of the main electronic expansion valve is connected to the first end of the liquid storage tank, the second end of the liquid storage tank is connected to the first end of the diverter, the second end of the diverter is connected to the first end of at least one branch electronic expansion valve, the second end of at least one branch electronic expansion valve is connected to the first end of the battery cold plate on the corresponding branch, and the second end of the battery cold plate is connected to the fourth end of the regenerator. This system can form a refrigeration cycle to cool the energy storage battery when cooling is required, and form a heating cycle to heat the energy storage battery when heating is required. This can prevent the operating temperature of the energy storage battery from being too high or too low, thereby improving the charging and discharging efficiency of the energy storage battery. It also has reliable performance and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 Schematic diagram of a thermal management system for an energy storage battery according to an embodiment of the present application.

[0043] Figure 2 This is a first schematic diagram of a refrigeration cycle provided in one embodiment of the present application.

[0044] Figure 3 This is a first schematic diagram of a heating cycle provided in one embodiment of the present application.

[0045] Figure 4 This is a second schematic diagram of a refrigeration cycle provided in one embodiment of the present application.

[0046] Figure 5 This is a second schematic diagram of a heating cycle provided in one embodiment of the present application.

[0047] Figure 6 This is a third schematic diagram of a refrigeration cycle provided in one embodiment of the present application.

[0048] Figure 7 This is a third schematic diagram of a heating cycle provided in an embodiment of the present application.

[0049] Figure 8 This is a flow chart of a method for controlling a total electronic expansion valve provided in one embodiment of the present application.

[0050] Figure 9 This is a flow chart of a control method for a branch electronic expansion valve provided in one embodiment of the present application.

[0051] Reference numerals:

[0052] Compressor 1, first multi-way valve 2, valve assembly 3, outdoor heat exchanger 4, regenerator 5, main electronic expansion valve 6, liquid storage tank 7, diverter 8, branch electronic expansion valve 9, battery cold plate 10, filter 11, first one-way valve 31, second one-way valve 32, third one-way valve 33, fourth one-way valve 34, second multi-way valve 30, first port 301, second port 302, third port 303, fourth port 304. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0054] It should be noted that although the device schematics illustrate functional module divisions and the flowcharts illustrate logical sequences, in certain circumstances, the steps shown or described may be performed in a sequence that differs from the module divisions in the device or the sequence in the flowcharts. The terms "first," "second," and so on, in the specification, claims, and drawings, are used to distinguish similar items and are not necessarily used to describe a specific sequence or precedence.

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein are for the purpose of describing the embodiments of this application only and are not intended to limit this application.

[0056] In the existing technology, most energy storage battery thermal management systems use liquid cooling or air cooling solutions. The air cooling solution uses an air conditioner to blow cold or hot air through the air duct to the battery pack to achieve battery temperature control. This solution is complex in structure and has poor temperature uniformity. The liquid cooling solution uses an air conditioning unit to first cool or heat the coolant, generally an ethylene glycol solution, which then exchanges heat with the battery through the battery cold plate to achieve battery temperature control. This solution has better temperature uniformity, but is costly. After the secondary heat exchange, the system suffers from heat exchange losses and the heat exchange response time becomes longer.

[0057] Based on this, the embodiments of the present application propose a thermal management system for energy storage batteries, which aims to use refrigerant to directly cool or heat energy storage batteries, and can reasonably control the temperature of the refrigerant entering the battery cold plate, with reliable performance and low cost.

[0058] The energy storage battery in the embodiment of the present application can be a power battery in a vehicle, a battery in an energy storage device in a photovoltaic power generation system, etc.

[0059] Reference Figure 1 , Figure 1 The figure is a schematic diagram of an energy storage battery thermal management system provided in one embodiment of the present application. The energy storage battery thermal management system provided in this embodiment of the present application includes a compressor 1, a first multi-way valve 2, a valve assembly 3, an outdoor heat exchanger 4, a regenerator 5, a main electronic expansion valve 6, a liquid storage tank 7, a flow divider 8, at least one branch electronic expansion valve 9, and at least one battery cold plate 10. Each branch where a battery cold plate 10 is located can be equipped with a corresponding branch electronic expansion valve 9, and each battery cold plate 10 is in contact with an energy storage battery.

[0060] Among them, Figure 1 As shown, the first end of the compressor 1 is connected to the first end of the first multi-way valve 2, the second end of the first multi-way valve 2 is connected to the first end of the valve assembly 3, and the third end of the first multi-way valve 2 is also connected to the first end of the regenerator 5.

[0061] The second end of the valve assembly 3 is connected to the first end of the outdoor heat exchanger 4, the second end of the outdoor heat exchanger 4 is connected to the second end of the regenerator 5, the third end of the regenerator 5 is connected to the third end of the valve assembly 3, and the fourth end of the valve assembly 3 is also connected to the first end of the main electronic expansion valve 6.

[0062] The second end of the main electronic expansion valve 6 is connected to the first end of the liquid storage tank 7, the second end of the liquid storage tank 7 is connected to the first end of the diverter 8, the second end of the diverter 8 is connected to the first end of at least one branch electronic expansion valve 9, the second end of at least one branch electronic expansion valve 9 is connected to the first end of the battery cold plate 10 on the corresponding branch, and the second end of the battery cold plate 10 is connected to the fourth end of the regenerator 5.

[0063] In the embodiment of the present application, a plurality of battery cold plates 10 may be provided, which are respectively provided on a plurality of branches. The battery cold plates 10 of each branch are connected in parallel. A branch electronic expansion valve may be provided corresponding to each branch to control the refrigerant flow on the corresponding branch, thereby ensuring the temperature consistency and uniformity of the battery cold plates 10.

[0064] In the embodiments of the present application, when the energy storage battery needs to be cooled, a refrigeration cycle can be established to cool the energy storage battery. When the energy storage battery needs to be heated, a heating cycle can be established to heat the energy storage battery. This prevents the energy storage battery from operating at too high or too low a temperature, thereby improving the battery's charge and discharge efficiency. Furthermore, this system uses refrigerant to directly cool or heat the energy storage battery, effectively controlling the temperature of the refrigerant entering the battery cold plate. This provides reliable performance and low cost.

[0065] It should be noted that the first multi-way valve 2 may include a first port, a second port, a third port, and a fourth port. The first port in the first multi-way valve 2 can communicate with the second port to form a first flow path a, and the third port can communicate with the fourth port to form a second flow path b. The third port in the first multi-way valve 2 can communicate with the first port to form a third flow path c, and the fourth port can communicate with the second port to form a third flow path d. The flow rate of the first flow path a is adjustable, the flow rate of the second flow path b is adjustable, the flow rate of the third flow path c is adjustable, and the flow rate of the fourth flow path d is adjustable.

[0066] In some embodiments, the first multi-way valve 2 may be a four-way valve, which includes a valve body and a valve core, the valve body being provided with a first port, a second port, a third port and a fourth port, and the valve core being arranged in the valve body to control the opening of the first port, the second port, the third port and the fourth port.

[0067] It should be noted that the embodiments of the present application do not specifically limit the first multi-way valve 2. As long as a first port, a second port, a third port, and a fourth port are provided, and the first port in the first multi-way valve 2 can communicate with the second port to form a first flow path a, and the third port can communicate with the fourth port to form a second flow path b, the third port in the first multi-way valve 2 can communicate with the first port to form a third flow path c, and the fourth port can communicate with the second port to form a third flow path d, the first multi-way valve 2 can be configured as a four-way valve, a five-way valve, a six-way valve, a seven-way valve, an eight-way valve, etc.

[0068] In some embodiments, reference Figure 1 The energy storage battery thermal management system also includes a filter 11. Specifically, a filter 11 can be disposed between the fourth end of the valve assembly 3 and the first end of the master electronic expansion valve 6, and between the second end of the master electronic expansion valve 6 and the first end of the liquid storage tank 7. Furthermore, a filter 11 can be disposed between the second end of the liquid storage tank 7 and the first end of at least one branch electronic expansion valve 9, and between the second end of at least one branch electronic expansion valve 9 and the first end of the battery cold plate 10 on the corresponding branch.

[0069] In the embodiment of the present application, by providing a filter 11 before the main electronic expansion valve 6, impurities in the refrigerant can be filtered, thereby preventing impurities from entering the main electronic expansion valve 6. By providing a filter 11 after the main electronic expansion valve 6, impurities can be prevented from entering the liquid storage tank 7.

[0070] In the embodiment of the present application, a filter 11 is provided before each branch electronic expansion valve 9 to prevent impurities from entering each branch electronic expansion valve 9. A filter 11 is provided after each branch electronic expansion valve 9 to prevent impurities from entering each branch battery cold plate 10.

[0071] In some embodiments, reference Figure 2 , Figure 2 This is a first schematic diagram of a refrigeration cycle provided by an embodiment of the present application. When the energy storage battery needs to be cooled, the energy storage battery thermal management system can form a refrigeration cycle to cool the energy storage battery. Figure 2 As shown, the refrigeration cycle loop includes a compressor 1, a first multi-way valve 2, a valve assembly 3, an outdoor heat exchanger 4, a regenerator 5, a valve assembly 3, a main electronic expansion valve 6, a liquid storage tank 7, a diverter 8, at least one branch electronic expansion valve 9, at least one battery cold plate 10, a regenerator 5 and a compressor 1, which are connected in sequence to form a loop.

[0072] In the embodiment of the present application, when the energy storage battery needs to be cooled, the energy storage battery thermal management system turns on the cooling mode. At this time, the connection positions of the four ports of the first multi-way valve 2 can be changed, such as Figure 2As shown, the high-temperature and high-pressure refrigerant discharged from the compressor 1 enters the outdoor heat exchanger 4 through the first multi-way valve 2 and the valve assembly 3. The outdoor heat exchanger 4 condenses the refrigerant into a high-pressure and medium-temperature liquid. The liquid then enters the regenerator 5 to exchange heat with the suction air of the compressor 1. The liquid after heat exchange can be further cooled. The liquid coming out of the regenerator 5 enters the main electronic expansion valve 6 through the valve assembly 3 for preliminary pressure reduction. The refrigerant after pressure reduction enters the liquid storage tank 7. The two pipes in the liquid storage tank 7 can both extend to the bottom of the liquid storage tank 7, so that the liquid refrigerant can be stored at the bottom of the liquid storage tank 7, thereby ensuring that the refrigerant leaving the liquid storage tank 7 is in liquid form, thereby reducing the dryness after subsequent throttling, reducing the specific enthalpy of the refrigerant, and increasing the cooling capacity. The liquid storage tank 7 can also be used to store excess refrigerant. The refrigerant exiting the liquid storage tank 7 is diverted by a flow divider 8 and enters the branch electronic expansion valves 9 on each branch line, where it is further throttled, depressurized, and cooled, becoming a low-temperature, low-pressure gas-liquid two-phase state. The gas-liquid two-phase refrigerant then enters the battery cold plate 10, where it evaporates and absorbs heat, thereby cooling the energy storage battery. The refrigerant exiting the battery cold plate 10 then passes through the regenerator 5, which heats up any remaining refrigerant, ensuring that it is completely gaseous before entering the compressor 1, preventing liquid hammering. Finally, the refrigerant returns to the compressor through the first multi-way valve 2, thus forming a refrigeration cycle.

[0073] In the embodiment of the present application, when the energy storage battery needs to be cooled, the following Figure 2 The refrigeration cycle shown is used to cool the energy storage battery and prevent the operating temperature of the energy storage battery from being too high.

[0074] In some embodiments, reference Figure 3 , Figure 3 This is a first schematic diagram of a heating cycle provided by an embodiment of the present application. When the energy storage battery needs to be heated, the energy storage battery thermal management system can form a heating cycle to heat the energy storage battery. Figure 3 As shown, the heating cycle loop includes a compressor 1, a first multi-way valve 2, a regenerator 5, at least one battery cold plate 10, at least one branch electronic expansion valve 9, a diverter 8, a liquid storage tank 7, a main electronic expansion valve 6, a valve assembly 3, an outdoor heat exchanger 4, a regenerator 5, a valve assembly 3, a first multi-way valve 2 and a compressor 1, which are connected in sequence to form a loop.

[0075] In the embodiment of the present application, when the energy storage battery needs to be heated, the energy storage battery thermal management system turns on the heating mode. At this time, the connection positions of the four ports of the first multi-way valve 2 can be changed, such as Figure 3As shown, the high-temperature, high-pressure refrigerant discharged from compressor 1 passes through first multi-way valve 2, then first passes through regenerator 5 to exchange heat with the compressor 1 intake air for cooling before entering battery cold plate 10. During this process, the heat exchange area in regenerator 5 can be adjusted through heat exchange calculations to ensure that the temperature entering battery cold plate 10 does not exceed the maximum temperature the energy storage batteries can withstand (typically 40°C), thereby protecting the energy storage batteries from overheating and damage. After heating the energy storage batteries in battery cold plate 10, the refrigerant condenses into a liquid state and enters the branch electronic expansion valve 9 on each branch circuit. At this time, the branch electronic expansion valve 9 on each branch circuit remains fully open. After passing through the branch electronic expansion valve 9, the refrigerant passes through diverter 8 and enters liquid storage tank 7. Liquid storage tank 7 serves as a storage tank for excess refrigerant. After exiting liquid storage tank 7, the refrigerant passes through main electronic expansion valve 6 for throttling, pressure reduction, and temperature reduction, becoming a low-temperature, low-pressure gas-liquid two-phase state. It then passes through valve assembly 3 and enters outdoor heat exchanger 4. The low-temperature, low-pressure, gas-liquid two-phase refrigerant exchanges heat with the air in outdoor heat exchanger 4, evaporating and absorbing heat before entering regenerator 5. Any refrigerant that hasn't fully evaporated in regenerator 5 continues to evaporate, ensuring that the refrigerant entering compressor 1 is completely gaseous, preventing compressor liquid hammer. The refrigerant then passes through valve assembly 3 and first multi-way valve 2 and returns to compressor 1, forming a heating cycle.

[0076] In the embodiment of the present application, when the energy storage battery needs to be heated, the following Figure 3 The heating cycle shown is used to heat up the energy storage battery, thereby preventing the operating temperature of the energy storage battery from being too low.

[0077] In some embodiments, reference Figure 4 and Figure 5 The valve assembly 3 may include a first one-way valve 31 , a second one-way valve 32 , a third one-way valve 33 and a fourth one-way valve 34 .

[0078] Among them, the output end of the first one-way valve 31 is connected to the input end of the second one-way valve 32, the input end of the second one-way valve 32 is also connected to the second end of the first multi-way valve 2, and the output end of the second one-way valve 32 is connected to the first end of the outdoor heat exchanger 4.

[0079] The input end of the first one-way valve 31 is connected to the third end of the regenerator 5, the input end of the fourth one-way valve 34 is connected to the third end of the regenerator 5, the output end of the fourth one-way valve 34 is connected to the input end of the third one-way valve 33, the output end of the fourth one-way valve 34 is also connected to the first end of the main electronic expansion valve 6, and the output end of the third one-way valve 33 is connected to the first end of the outdoor heat exchanger 4.

[0080] In the embodiment of the present application, the energy storage battery thermal management system further includes a controller, and the first one-way valve 31 , the second one-way valve 32 , the third one-way valve 33 and the fourth one-way valve 34 are all electrically connected to the controller.

[0081] Reference Figure 4 , Figure 4 This is a second schematic diagram of a refrigeration cycle provided by an embodiment of the present application. When cooling the energy storage battery, the controller opens the second and fourth one-way valves 32 and 34, and disconnects the first and third one-way valves 31 and 33. This connects the compressor 1, the first multi-way valve 2, the second one-way valve 32, the outdoor heat exchanger 4, the regenerator 5, the fourth one-way valve 34, the main electronic expansion valve 6, the liquid storage tank 7, the flow divider 8, at least one branch electronic expansion valve 9, at least one battery cold plate 10, the regenerator 5, and the compressor 1, forming a refrigeration cycle to cool the energy storage battery.

[0082] Reference Figure 5 , Figure 5 This is a second schematic diagram of a heating cycle provided by an embodiment of the present application. When the energy storage battery needs to be heated, the controller disconnects the second and fourth one-way valves 32 and 34, and connects the first and third one-way valves 31 and 33. This connects the compressor 1, the first multi-way valve 2, the regenerator 5, at least one battery cold plate 10, at least one branch electronic expansion valve 9, the flow divider 8, the liquid storage tank 7, the main electronic expansion valve 6, the third one-way valve 33, the outdoor heat exchanger 4, the regenerator 5, the first one-way valve 31, the first multi-way valve 2, and the compressor 1, forming a heating cycle to heat the energy storage battery.

[0083] In some embodiments, the valve assembly 3 may include a second multi-way valve 30, which may include a first port 301, a second port 302, a third port 303, and a fourth port 304. Within the second multi-way valve 30, the first port 301 and the second port 302 are connected to form a first flow path a, and the third port 303 and the fourth port 304 are connected to form a second flow path b. Within the second multi-way valve 30, the third port 303 and the first port 301 are connected to form a third flow path c, and the fourth port 304 and the second port 302 are connected to form a third flow path d. The flow rate of the first flow path a is adjustable, the flow rate of the second flow path b is adjustable, the flow rate of the third flow path c is adjustable, and the flow rate of the fourth flow path d is adjustable.

[0084] In some embodiments, the second multi-way valve 30 may be a four-way valve, which includes a valve body and a valve core. The valve body is provided with a first port 301, a second port 302, a third port 303 and a fourth port 304. The valve core is arranged in the valve body to control the opening of the first port 301, the second port 302, the third port 303 and the fourth port 304.

[0085] It should be noted that the second multi-way valve 30 is not specifically limited in the present embodiment. As long as the second multi-way valve 30 is provided with a first port 301, a second port 302, a third port 303, and a fourth port 304, and the first port 301 and the second port 302 are connected to form a first flow path a, and the third port 303 and the fourth port 304 are connected to form a second flow path b, the third port 303 and the first port 301 are connected to form a third flow path c, and the fourth port 304 and the second port 302 are connected to form a third flow path d, the second multi-way valve 30 can be configured as a four-way valve, a five-way valve, a six-way valve, a seven-way valve, an eight-way valve, etc.

[0086] It should be noted that the valve assembly 3 may be composed of multiple one-way valves, and may be a multi-way valve other than the first multi-way valve or higher, or may be composed of a combination of one-way valves and multi-way valves. The embodiment of the present application does not specifically limit the valve assembly 3.

[0087] In the embodiment of the present application, the energy storage battery thermal management system further includes a controller, and the second multi-way valve 30 is electrically connected to the controller.

[0088] Reference Figure 6 , Figure 6 This is a third schematic diagram of a refrigeration cycle provided by an embodiment of the present application. When cooling the energy storage battery is required, the controller controls the first port 301 of the second multi-way valve 30 to communicate with the second port 302, and controls the third port 303 of the second multi-way valve 30 to communicate with the fourth port 304. This connects the compressor 1, the first multi-way valve 2, the first port 301, the second port 302, the outdoor heat exchanger 4, the regenerator 5, the third port 303, the fourth port 304, the main electronic expansion valve 6, the liquid storage tank 7, the flow divider 8, at least one branch electronic expansion valve 9, at least one battery cold plate 10, the regenerator 5, and the compressor 1 in sequence to form a refrigeration cycle to cool the energy storage battery.

[0089] Reference Figure 7 , Figure 7 This is a third schematic diagram of a heating cycle provided by an embodiment of the present application. When the energy storage battery needs to be heated, the controller controls the fourth port 304 of the second multi-way valve 30 to communicate with the second port 302, and controls the third port 303 of the second multi-way valve 30 to communicate with the first port 301, so that the compressor 1, the first multi-way valve 2, the regenerator 5, at least one battery cold plate 10, at least one branch electronic expansion valve 9, the diverter 8, the liquid storage tank 7, the main electronic expansion valve 6, the fourth port 304, the second port 302, the outdoor heat exchanger 4, the regenerator 5, the third port 303, the first port 301, the first multi-way valve 2, and the compressor 1 are sequentially connected to form a heating cycle to heat the energy storage battery.

[0090] In some embodiments, the energy storage battery thermal management system further includes a pressure sensor, a first temperature sensor, and a controller. The pressure sensor can be positioned between the first end of compressor 1 and the first end of first multi-way valve 2 to measure the exhaust pressure of compressor 1. The first temperature sensor, positioned at the first end of compressor 1, measures the exhaust temperature of compressor 1. The main electronic expansion valve 6, the pressure sensor, and the first temperature sensor are all electrically connected to the controller.

[0091] When the energy storage battery thermal management system forms a cooling cycle or a heating cycle, the total electronic expansion valve 6 is controlled by the controller. Figure 8 , Figure 8 This is a flowchart of a method for controlling a total electronic expansion valve provided in one embodiment of the present application, including but not limited to steps S810 to S870.

[0092] Step S810, acquiring the exhaust pressure of the compressor acquired by the pressure sensor and the exhaust temperature of the compressor acquired by the first temperature sensor;

[0093] Step S820, calculating the exhaust superheat of the compressor based on the exhaust pressure and exhaust temperature of the compressor;

[0094] Step S830, determining whether the exhaust superheat of the compressor is greater than a first preset value;

[0095] Step S840: If the exhaust gas superheat of the compressor is greater than a first preset value, the opening of the main electronic expansion valve is increased;

[0096] Step S850: If the exhaust gas superheat of the compressor is not greater than the first preset value, determine whether the exhaust gas superheat of the compressor is less than the first preset value;

[0097] Step S860: If the exhaust superheat of the compressor is less than the first preset value, control the opening of the main electronic expansion valve to decrease;

[0098] In step S870, if the exhaust gas superheat of the compressor is equal to the first preset value, the opening of the main electronic expansion valve is controlled to remain unchanged.

[0099] In this embodiment of the present application, the opening of the master electronic expansion valve 6 can be controlled based on the exhaust superheat of compressor 1 to ensure sufficient refrigerant flow in the energy storage battery thermal management system and prevent liquid backflow in compressor 1. Specifically, the compressor exhaust pressure pd, as detected by the pressure sensor, and the compressor exhaust temperature Td, as detected by the first temperature sensor, are first acquired. Based on the compressor exhaust pressure pd, as detected by the pressure sensor, the saturated condensing temperature Tc corresponding to the exhaust pressure of compressor 1 can be calculated. The compressor exhaust superheat is then calculated by subtracting the saturated condensing temperature Tc from the compressor exhaust temperature Td, as detected by the first temperature sensor. The compressor exhaust superheat is then compared with a first preset value. When the compressor exhaust superheat exceeds the first preset value, the opening of the master electronic expansion valve is increased; when the compressor exhaust superheat is less than the first preset value, the opening of the master electronic expansion valve is decreased; and when the compressor exhaust superheat equals the first preset value, the opening of the master electronic expansion valve is maintained unchanged. This ensures sufficient refrigerant flow in the energy storage battery thermal management system.

[0100] In some embodiments, the energy storage battery thermal management system further includes a second temperature sensor, a third temperature sensor, and a controller. The second temperature sensor can be positioned between the second end of at least one branch electronic expansion valve 9 and the first end of the battery cold plate 10 on the corresponding branch, and is used to measure the inlet temperature of the battery cold plate. The third temperature sensor can be positioned between the second end of the battery cold plate 10 and the fourth end of the regenerator 5, and is used to measure the outlet temperature of the battery cold plate 10. The at least one branch electronic expansion valve 9, the second temperature sensor, and the third temperature sensor are all electrically connected to the controller.

[0101] When the energy storage battery thermal management system forms a refrigeration cycle, the branch electronic expansion valve 9 on each branch is controlled by the controller. Figure 9 , Figure 9 This is a flowchart of a method for controlling a branch electronic expansion valve provided in one embodiment of the present application, including but not limited to steps S910 to S970.

[0102] Step S910, acquiring the inlet temperature of the battery cold plate acquired by the second temperature sensor and the outlet temperature of the battery cold plate acquired by the third temperature sensor;

[0103] Step S920, calculating the superheat of the battery cold plate based on the inlet temperature and outlet temperature of the battery cold plate;

[0104] Step S930, determining whether the overheating degree of the battery cold plate is greater than a second preset value;

[0105] Step S940: If the overheat of the battery cold plate is greater than a second preset value, controlling the opening of the branch electronic expansion valve to increase;

[0106] Step S950: If the overheat degree of the battery cold plate is not greater than the second preset value, determine whether the overheat degree of the battery cold plate is less than the second preset value;

[0107] Step S960: If the superheat of the battery cold plate is less than a second preset value, controlling the opening of the branch electronic expansion valve to decrease;

[0108] In step S970 , if the superheat degree of the battery cold plate is equal to the second preset value, the opening degree of the electronic expansion valve of the control branch is maintained unchanged.

[0109] In the embodiment of the present application, when the energy storage battery thermal management system forms a refrigeration cycle loop, the opening of the branch electronic expansion valve 9 can be controlled by the superheat of the battery cold plate 10 on the corresponding branch to ensure that the refrigerant can fully evaporate and exchange heat. When the superheat of the battery cold plate 10 on a certain branch is low, it means that the refrigerant flow on the branch is too large, so the opening of the branch electronic expansion valve 9 can be reduced to reduce the refrigerant flow on the branch; when the superheat of the battery cold plate 10 on a certain branch is high, it means that the refrigerant flow on the branch is too small, so the opening of the branch electronic expansion valve 9 can be increased to increase the refrigerant flow on the branch, thereby ensuring that the refrigerant in each branch is evenly distributed to ensure the temperature uniformity of the entire battery cold plate 10.

[0110] Specifically, the battery cold plate inlet temperature Tin, as measured by the second temperature sensor, and the battery cold plate outlet temperature Tout, as measured by the third temperature sensor, are first acquired. The battery cold plate inlet temperature Tin, as measured by the second temperature sensor, is then subtracted from the battery cold plate outlet temperature Tout, as measured by the third temperature sensor, to determine the battery cold plate superheat. The battery cold plate superheat is then compared with a second preset value. When the battery cold plate superheat exceeds the second preset value, the opening of the branch electronic expansion valve is increased. When the battery cold plate superheat is less than the second preset value, the opening of the branch electronic expansion valve is decreased. When the battery cold plate superheat equals the second preset value, the opening of the branch electronic expansion valve remains unchanged. This ensures uniform refrigerant distribution across each branch, thereby ensuring temperature uniformity across the entire battery cold plate 10.

[0111] When the energy storage battery thermal management system forms a heating cycle, the branch electronic expansion valves 9 on each branch are fully open. This is because in the heating cycle, the refrigerant entering the battery cold plate 10 is in gaseous form, with a relatively fast flow rate and relatively uniform flow distribution. The energy storage battery has a low heating demand, so no flow distribution adjustment is required during heating.

[0112] The embodiments described in the embodiments of this application are intended to more clearly illustrate the technical solutions of the embodiments of this application and do not constitute a limitation on the technical solutions provided by the embodiments of this application. Those skilled in the art will appreciate that with the evolution of technology and the emergence of new application scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0113] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of the present application, and may include more or fewer steps than shown in the figures, or a combination of certain steps, or different steps.

[0114] Those skilled in the art will appreciate that all or some of the steps in the methods, systems, and functional modules / units in the devices disclosed above may be implemented as software, firmware, hardware, or appropriate combinations thereof.

[0115] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0116] It should be understood that in this application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0117] The preferred embodiments of the present invention are described above with reference to the accompanying drawings, but are not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and essence of the present invention should be within the scope of the present invention.

Claims

1. A thermal management system for an energy storage battery, characterized in that: The system comprises a compressor, a first multi-way valve, a valve assembly, an outdoor heat exchanger, a regenerator, a main electronic expansion valve, a liquid storage tank, a flow divider, at least one branch electronic expansion valve, and at least one battery cold plate, wherein each branch where the battery cold plate is located is correspondingly equipped with a branch electronic expansion valve, and each battery cold plate is in contact with an energy storage battery; The first end of the compressor is in communication with the first end of the first multi-way valve, the second end of the first multi-way valve is in communication with the first end of the valve assembly, and the third end of the first multi-way valve is also in communication with the first end of the regenerator; The second end of the valve assembly is in communication with the first end of the outdoor heat exchanger, the second end of the outdoor heat exchanger is in communication with the second end of the regenerator, the third end of the regenerator is in communication with the third end of the valve assembly, and the fourth end of the valve assembly is also in communication with the first end of the main electronic expansion valve; The second end of the main electronic expansion valve is in communication with the first end of the liquid storage tank, the second end of the liquid storage tank is in communication with the first end of the diverter, the second end of the diverter is in communication with the first end of at least one branch electronic expansion valve, the second end of at least one branch electronic expansion valve is in communication with the first end of the battery cold plate on the corresponding branch, and the second end of the battery cold plate is in communication with the fourth end of the regenerator; The system includes a refrigeration cycle circuit, which includes the compressor, the first multi-way valve, the valve assembly, the outdoor heat exchanger, the regenerator, the valve assembly, the main electronic expansion valve, the liquid storage tank, the flow divider, the at least one branch electronic expansion valve, the at least one battery cold plate, the regenerator, and the compressor, which are sequentially connected to form a loop; The system also includes a heating circulation loop, which includes the compressor, the first multi-way valve, the regenerator, the at least one battery cold plate, the at least one branch electronic expansion valve, the diverter, the liquid storage tank, the main electronic expansion valve, the valve assembly, the outdoor heat exchanger, the regenerator, the valve assembly, the first multi-way valve and the compressor, which are connected in sequence to form a loop.

2. The system according to claim 1, wherein: The system also includes a filter; A filter is provided between the fourth end of the valve assembly and the first end of the main electronic expansion valve, and a filter is provided between the second end of the main electronic expansion valve and the first end of the liquid storage tank; and / or, A filter is provided between the second end of the liquid storage tank and the first end of at least one branch electronic expansion valve, and a filter is provided between the second end of at least one branch electronic expansion valve and the first end of the battery cold plate on the corresponding branch.

3. The system according to claim 1, wherein: The valve assembly includes a first one-way valve, a second one-way valve, a third one-way valve and a fourth one-way valve; The output end of the first one-way valve is communicated with the input end of the second one-way valve, the input end of the second one-way valve is also communicated with the second end of the first multi-way valve, and the output end of the second one-way valve is communicated with the first end of the outdoor heat exchanger; The input end of the first one-way valve is connected to the third end of the regenerator, the input end of the fourth one-way valve is connected to the third end of the regenerator, the output end of the fourth one-way valve is connected to the input end of the third one-way valve, the output end of the fourth one-way valve is also connected to the first end of the main electronic expansion valve, and the output end of the third one-way valve is connected to the first end of the outdoor heat exchanger.

4. The system according to claim 3, characterized in that The system further includes a controller, the first one-way valve, the second one-way valve, the third one-way valve, and the fourth one-way valve are all electrically connected to the controller, and the controller is configured to: When the energy storage battery needs to be cooled, the second one-way valve and the fourth one-way valve are controlled to be connected, and the first one-way valve and the third one-way valve are controlled to be disconnected, so that the compressor, the first multi-way valve, the second one-way valve, the outdoor heat exchanger, the regenerator, the fourth one-way valve, the main electronic expansion valve, the liquid storage tank, the flow divider, the at least one branch electronic expansion valve, the at least one battery cold plate, the regenerator, and the compressor are connected in sequence to form the refrigeration cycle to cool the energy storage battery; When the energy storage battery needs to be heated, the second one-way valve and the fourth one-way valve are controlled to be disconnected, and the first one-way valve and the third one-way valve are controlled to be connected, so that the compressor, the first multi-way valve, the regenerator, the at least one battery cold plate, the at least one branch electronic expansion valve, the diverter, the liquid storage tank, the main electronic expansion valve, the third one-way valve, the outdoor heat exchanger, the regenerator, the first one-way valve, the first multi-way valve and the compressor are connected in sequence to form the heating cycle to heat the energy storage battery.

5. The system according to claim 1, wherein: The valve assembly includes a second multi-way valve, the second multi-way valve including a first port, a second port, a third port, and a fourth port; The first port is in communication with the second end of the first multi-way valve, and the second port is in communication with the first end of the outdoor heat exchanger; The third port is communicated with the third end of the regenerator, and the fourth port is communicated with the first end of the main electronic expansion valve.

6. The system according to claim 5, characterized in that The system further includes a controller, the second multi-way valve is electrically connected to the controller, and the controller is configured to: When the energy storage battery needs to be cooled, the first port is controlled to be connected to the second port, and the third port is controlled to be connected to the fourth port, so that the compressor, the first multi-way valve, the first port, the second port, the outdoor heat exchanger, the regenerator, the third port, the fourth port, the main electronic expansion valve, the liquid storage tank, the flow divider, the at least one branch electronic expansion valve, the at least one battery cold plate, the regenerator, and the compressor are connected in sequence to form the refrigeration cycle to cool the energy storage battery; When the energy storage battery needs to be heated, the fourth port is controlled to be connected to the second port, and the third port is controlled to be connected to the first port, so that the compressor, the first multi-way valve, the regenerator, the at least one battery cold plate, the at least one branch electronic expansion valve, the diverter, the liquid storage tank, the main electronic expansion valve, the fourth port, the second port, the outdoor heat exchanger, the regenerator, the third port, the first port, the first multi-way valve and the compressor are connected in sequence to form the heating cycle to heat the energy storage battery.

7. The system according to claim 1, wherein: The system further includes a pressure sensor, a first temperature sensor, and a controller. The pressure sensor is disposed between the first end of the compressor and the first end of the first multi-way valve, and is used to collect the exhaust pressure of the compressor. The first temperature sensor is disposed at the first end of the compressor, and is used to collect the exhaust temperature of the compressor. The main electronic expansion valve, the pressure sensor, and the first temperature sensor are all electrically connected to the controller, and the controller is further configured to: acquiring the exhaust pressure of the compressor acquired by the pressure sensor and the exhaust temperature of the compressor acquired by the first temperature sensor, and calculating the exhaust superheat of the compressor based on the exhaust pressure and the exhaust temperature of the compressor; comparing the exhaust superheat of the compressor with a first preset value; When the exhaust superheat of the compressor is greater than the first preset value, controlling to increase the opening of the total electronic expansion valve; When the exhaust superheat of the compressor is less than the first preset value, controlling to reduce the opening of the total electronic expansion valve; When the exhaust gas superheat of the compressor is equal to the first preset value, the opening of the total electronic expansion valve is controlled to remain unchanged.

8. The system according to claim 1, wherein: The system further includes a second temperature sensor, a third temperature sensor, and a controller. The second temperature sensor is disposed between the second end of at least one branch electronic expansion valve and the first end of the battery cold plate on the corresponding branch, and is used to collect the inlet temperature of the battery cold plate. The third temperature sensor is disposed between the second end of the battery cold plate and the fourth end of the regenerator, and is used to collect the outlet temperature of the battery cold plate. The at least one branch electronic expansion valve, the second temperature sensor, and the third temperature sensor are all electrically connected to the controller, and the controller is configured as follows: When the energy storage battery needs to be cooled, obtaining the inlet temperature of the battery cold plate acquired by the second temperature sensor and the outlet temperature of the battery cold plate acquired by the third temperature sensor, and calculating the superheat of the battery cold plate based on the inlet temperature and the outlet temperature of the battery cold plate; comparing the overheat degree of the battery cold plate with a second preset value; When the overheat degree of the battery cold plate is greater than the second preset value, controlling to increase the opening degree of the branch electronic expansion valve on the corresponding branch; When the overheat degree of the battery cold plate is less than the second preset value, controlling to reduce the opening degree of the branch electronic expansion valve on the corresponding branch; When the superheat degree of the battery cold plate is equal to the second preset value, the opening degree of the branch electronic expansion valve on the corresponding branch is controlled to remain unchanged.

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