Energy storage system and control method therefor

Abstract

An energy storage system and a control method therefor. The energy storage system (10) comprises: a battery (12) configured to store and release energy; an energy storage converter (13) configured to be connected to a power supply source and the battery (12); and a thermal management system (11). The thermal management system (11) comprises: a first liquid cooling circulation loop (20) comprising a first heat exchanger (21) configured to perform heat exchange with the battery (12); a second liquid cooling circulation loop (30) comprising a second heat exchanger (31) configured to perform heat exchange with the energy storage converter (13); and a third heat exchanger (111) connected to both the first liquid cooling circulation loop (20) and the second liquid cooling circulation loop (30), and configured to achieve heat exchange between a cooling liquid in the first liquid cooling circulation loop (20) and a cooling liquid in the second liquid cooling circulation loop (30).

Description

Energy storage systems and their control methods

[0001] Cross-reference to related applications

[0002] This application is based on and claims priority to CN application number 202411215146.8, filed on August 30, 2024, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] This invention relates to the field of energy storage technology, and in particular to an energy storage system and its control method. Background Technology

[0004] With increasing environmental pollution, the new energy industry is attracting more and more attention. Within this industry, battery technology is a crucial factor in its development. Rechargeable batteries, which can be reactivated after discharge, have broad application prospects in large-scale energy storage. Summary of the Invention

[0005] In one aspect of this disclosure, an energy storage system is provided, comprising: a battery for storing and releasing energy; an energy storage converter for connecting a power supply source and the battery; and a thermal management system; wherein the thermal management system comprises: a first liquid-cooled circulation loop including a first heat exchanger for exchanging heat with the battery; a second liquid-cooled circulation loop including a second heat exchanger for exchanging heat with the energy storage converter; and a third heat exchanger connected to both the first and second liquid-cooled circulation loops and configured to achieve heat exchange between the coolant in the first liquid-cooled circulation loop and the coolant in the second liquid-cooled circulation loop.

[0006] In this embodiment, a first heat exchanger that exchanges heat with the battery and a second heat exchanger that exchanges heat with the energy storage converter are respectively located in a first liquid cooling loop and a second liquid cooling loop. The first and second liquid cooling loops exchange heat between the coolant via a third heat exchanger. This structure, which places the first and second heat exchangers in different liquid cooling loops, allows for independent configuration and control based on the thermal management requirements of the battery and the energy storage converter, thus meeting more flexible thermal management needs. Furthermore, the third heat exchanger transfers the coolant from the lower-temperature first liquid cooling loop (which exchanges heat with the battery) to the second liquid cooling loop to cool the higher-temperature energy storage converter. Conversely, the third heat exchanger also transfers heat from the higher-temperature second liquid cooling loop (which exchanges heat with the energy storage converter) to the first liquid cooling loop to heat the lower-temperature battery.

[0007] In some embodiments, the thermal management system further includes a heater disposed in the first liquid cooling circulation loop and configured to heat the coolant to be flowed into the first heat exchanger.

[0008] In this embodiment, by placing the heater in the first liquid cooling circulation loop, the coolant flowing through the heater in the first liquid cooling circulation loop can be heated to increase the temperature of the coolant before it flows into the first heat exchanger, thereby raising the battery temperature through the first heat exchanger when the battery temperature is low.

[0009] In some embodiments, the energy storage system further includes: a housing; wherein the battery is located inside the housing and the energy storage converter is located outside the housing.

[0010] In this embodiment, the energy storage converter is placed outside the battery housing, which allows the housing to accommodate more and larger batteries, thereby increasing the energy storage system's capacity.

[0011] In some embodiments, the thermal management system further includes: a refrigerant circulation loop including an evaporator and configured to implement refrigerant circulation, wherein the first liquid-cooled circulation loop has a coolant flow path through the evaporator, and the refrigerant in the refrigerant circulation loop exchanges heat with the coolant flow path through the evaporator.

[0012] In this embodiment, heat exchange between the refrigerant circulation loop and the first liquid cooling circulation loop provides cooling or heating to the coolant in the first liquid cooling circulation loop, which improves the thermal management efficiency of the first liquid cooling circulation loop and increases the configuration flexibility for different thermal management needs. Furthermore, the refrigerant circulation loop enables refrigerant circulation, and heat exchange occurs between the evaporator and the first liquid cooling circulation loop through the coolant flow path of the evaporator, effectively reducing the temperature of the coolant flowing in the first liquid cooling circulation loop and meeting the cooling requirements of the thermal management system.

[0013] In some embodiments, the thermal management system further includes a liquid cooling circulation bypass connected in parallel with the coolant flow path.

[0014] By connecting the liquid cooling circulation bypass in parallel with the coolant flow path, when the liquid cooling circulation bypass is activated, a portion of the coolant in the first liquid cooling circulation loop flows through the liquid cooling circulation bypass under the drive of the first pump, and then returns to the first liquid cooling circulation loop. This portion of coolant can be further heated or cooled by components installed in the liquid cooling circulation bypass. Accordingly, the thermal management system, which includes both a refrigerant circulation loop and a liquid cooling circulation bypass, has greater configuration flexibility and can meet more diverse thermal management needs.

[0015] In some embodiments, the liquid cooling circulation bypass includes a fourth heat exchanger and a valve, the fourth heat exchanger being configured to dissipate heat from the coolant flowing through the liquid cooling circulation bypass, and the valve being connected in series with the fourth heat exchanger and configured to operate on / off of the liquid cooling circulation bypass.

[0016] In this embodiment, by setting a valve in the liquid cooling circulation bypass, the valve is used to open and close the liquid cooling circulation bypass, so that the coolant in the first liquid cooling circulation loop is partially diverted to the liquid cooling circulation bypass for heat exchange as needed, or is not diverted to the liquid cooling circulation bypass for heat exchange, thereby increasing the controllability of the thermal management system.

[0017] In some embodiments, the refrigerant circulation loop further includes a condenser, and the fourth heat exchanger includes a coolant heat dissipation container disposed adjacent to the condenser; wherein the thermal management system further includes a fan configured to provide air cooling for the condenser and the coolant heat dissipation container.

[0018] In this embodiment, by arranging the condenser and the coolant heat dissipation container adjacent to each other and utilizing the airflow driven by a fan, both the condenser and the coolant heat dissipation container are simultaneously cooled by air, which helps improve air cooling efficiency and reduce energy consumption. In some embodiments, the thermal management system further includes a heater disposed in the first liquid cooling circulation loop; wherein, the energy storage system further includes a processor configured to operate the opening and closing states of the valves, the heater, and the refrigerant circulation loop according to the operating mode of the thermal management system.

[0019] In this embodiment, the processor can operate the opening and closing states of the valves, heaters, and refrigerant circulation loop according to the operating mode of the thermal management system, thereby satisfying the thermal management function played by the thermal management system in different operating modes.

[0020] In some embodiments, the processor is configured to: when the thermal management system is in a first operating mode, open the refrigerant circulation loop, close the valve, and shut down the heater.

[0021] In this embodiment, when the thermal management system is in the first working mode, the processor opens the refrigerant circulation loop, closes the valve, and shuts down the heater. The cooling capacity provided by the refrigerant circulation loop can be transferred to the first liquid cooling circulation loop through the evaporator, so as to improve the cooling effect of the battery through the first heat exchanger. The cooling capacity in the first liquid cooling circulation loop can also be transferred to the second liquid cooling circulation loop through the third heat exchanger, so as to improve the cooling effect of the energy storage converter through the second heat exchanger.

[0022] In some embodiments, the processor is configured to switch the thermal management system to the first operating mode in response to the temperature of the energy storage converter being greater than or equal to a first preset temperature T1.

[0023] In this embodiment, by comparing the energy storage converter with a threshold, the thermal management system switches to the first working mode, which can meet the situation where the energy storage converter has a high cooling demand. By utilizing the transfer of cooling capacity from the refrigerant circulation loop to the first liquid cooling circulation loop and from the first liquid cooling circulation loop to the second liquid cooling circulation loop, the cooling needs of the battery and the energy storage converter are met while saving the energy consumed by the refrigerant circulation system, which is beneficial to energy saving.

[0024] In some embodiments, the refrigerant circulation loop further includes a condenser, and the thermal management system further includes a fan configured to air-cool the condenser; wherein the processor is configured to turn on the fan when the thermal management system is in the first operating mode.

[0025] In this embodiment, the fan can improve the condensing efficiency of the condenser and enhance the cooling capacity of the refrigerant circulation loop in the first operating mode, thereby improving the cooling effect of the battery and energy storage converter.

[0026] In some embodiments, the processor is configured to: when the thermal management system is in a second operating mode, shut down the refrigerant circulation loop, open the valve, and shut down the heater.

[0027] In this embodiment, the liquid cooling circulation bypass is in the conducting state in the second working mode. At this time, the cooling or heat absorbed by the coolant flowing through the liquid cooling circulation bypass is provided to the battery when it flows back to the first liquid cooling circulation loop, and is transferred to the second liquid cooling circulation loop through heat exchange, which helps to meet the thermal management requirements of the battery and the energy storage converter.

[0028] In some embodiments, the processor is configured to switch the thermal management system to the second operating mode in response to an ambient temperature being less than or equal to a second preset temperature T2.

[0029] In this embodiment, by comparing the ambient temperature with a threshold, the thermal management system switches to the second operating mode. When the ambient temperature is low, the refrigerant circulation loop and heater are shut down, and the liquid cooling circulation bypass absorbs the cold energy from the environment, allowing the battery and energy storage converter to be cooled by natural cooling. The first pump in the first liquid cooling circulation loop drives the coolant into the liquid cooling circulation bypass, eliminating the need for additional drive components and shutting down the refrigerant circulation system, thereby saving energy to a greater extent.

[0030] In some embodiments, the fourth heat exchanger includes a coolant heat dissipation container, and the thermal management system further includes a fan configured to air-cool the coolant heat dissipation container; wherein the processor is configured to turn on the fan when the thermal management system is in the second operating mode.

[0031] With the help of the fan, the cooler ambient airflow can be accelerated to exchange heat with the coolant flowing through the coolant heat dissipation container, transferring the coldness from the environment to the liquid cooling circulation bypass, and then to the first liquid cooling circulation loop through the coolant. The first liquid cooling circulation loop transfers the coldness to the second liquid cooling circulation loop through the third heat exchanger, thereby effectively utilizing the natural coldness in the environment to meet the thermal management requirements of the battery and energy storage converter while reducing system energy consumption.

[0032] In some embodiments, the processor is configured to: shut down the refrigerant circulation loop, close the valve, and turn on the heater when the thermal management system is in a third operating mode.

[0033] In this embodiment, when the thermal management system is in the third operating mode, the processor closes the refrigerant circulation loop, closes the valve, and turns on the heater. The heater's heating effect increases the temperature of the coolant entering the first heat exchanger, thereby raising the battery temperature and improving battery performance, energy consumption, and efficiency. Furthermore, by closing the second valve, the coolant does not need to bypass the liquid cooling circulation loop for heat dissipation, thus avoiding an increase in the heater's heating load.

[0034] In some embodiments, the processor is configured to: in response to the battery temperature being less than or equal to a third preset temperature T3 and the coolant temperature in the upstream flow path of the first liquid cooling loop being less than a fourth preset temperature T4, switch the thermal management system to the third operating mode, wherein the third preset temperature T3 is less than the fourth preset temperature T4.

[0035] In this embodiment, by comparing the battery temperature and coolant temperature with respect to threshold values, the thermal management system can switch to the third operating mode to meet the heating requirements of the battery when its temperature is low. Furthermore, since the coolant itself is at a low temperature, a heater is used to raise its temperature, ensuring smooth battery heating. Moreover, the coolant used for battery heating can meet the cooling requirements of the energy storage converter, which has a higher temperature.

[0036] In some embodiments, the processor is configured to shut down the refrigerant circulation loop, close the valve, and shut down the heater when the thermal management system is in a fourth operating mode.

[0037] In this embodiment, by comparing the battery temperature and coolant temperature with respect to threshold values, the thermal management system can save energy to a greater extent when switching to the fourth operating mode. The temperature difference between the battery and the energy storage converter is used to heat the battery and cool the energy storage converter through the circulation and heat exchange of the coolant.

[0038] In some embodiments, the processor is configured to: in response to the battery temperature being less than or equal to a third preset temperature T3, and the coolant temperature of the first liquid cooling circulation loop located in the upstream flow path of the first heat exchanger being greater than or equal to a fourth preset temperature T4 and less than or equal to a fifth preset temperature T5, switch the thermal management system to the fourth operating mode, wherein the fourth preset temperature T4 is greater than the third preset temperature T3, and the fifth preset temperature T5 is greater than the fourth preset temperature T4.

[0039] In this embodiment, by comparing the battery temperature and coolant temperature with threshold values, the thermal management system switches to the fourth operating mode. This mode addresses the issue of low battery temperatures and high coolant temperatures. When the battery temperature is low and the coolant temperature is high, the system can meet the heating needs of the battery, improving battery performance, energy consumption, and efficiency. Furthermore, it eliminates the need for a heater when the coolant temperature is high, thus saving energy. Additionally, the coolant recovers heat through heat exchange with the energy storage converter and transfers it to the battery to raise its temperature.

[0040] In some embodiments, the processor is configured to: open the refrigerant circulation loop, close the valve, and close the heater when the thermal management system is in a fifth operating mode; and close the refrigerant circulation loop, close the valve, and close the heater when the thermal management system is in a sixth operating mode.

[0041] When the coolant temperature is high, it is difficult to effectively cool the battery through the first heat exchanger and the energy storage converter through the second heat exchanger. Therefore, in this embodiment, when the thermal management system is in the fifth operating mode, the processor opens the refrigerant circulation loop, closes the valve, and shuts down the heater, allowing the coolant to cool down through heat exchange with the refrigerant in the circulation loop, thereby more effectively cooling the battery and the energy storage converter. Furthermore, by closing the valve, the coolant bypasses the liquid cooling circulation and flows directly through the heat exchange pipe with the refrigerant, which helps improve the heat exchange efficiency of the evaporator. When the coolant temperature is increased, the thermal management system can operate in the sixth operating mode, in which the processor closes the refrigerant circulation loop, closes the valve, and shuts down the heater, saving energy consumed by the refrigerant circulation loop.

[0042] In some embodiments, the processor is configured to: switch the thermal management system to the fifth operating mode in response to the battery temperature being less than or equal to a third preset temperature T3 and the coolant temperature in the upstream flow path of the first liquid cooling circulation loop being greater than a fifth preset temperature T5; and switch the thermal management system to the sixth operating mode in response to the thermal management system being in the fifth operating mode and the coolant temperature in the upstream flow path of the first liquid cooling circulation loop being less than a fourth preset temperature T4; wherein the fifth preset temperature T5 is greater than the fourth preset temperature T4, and the fourth preset temperature T4 is greater than the third preset temperature T3.

[0043] In this embodiment, by comparing the battery temperature and coolant temperature with a threshold, when the thermal management system switches to the fifth working mode, it can efficiently cool the battery and the energy storage converter by means of a refrigerant circulation loop that exchanges heat with the coolant when the coolant temperature is high. The cooling requirements of the battery and the energy storage converter can be met, and the refrigerant circulation loop is shut off after the coolant temperature is reduced to a certain level, thereby saving energy consumption.

[0044] In some embodiments, the refrigerant circulation loop further includes a condenser, and the thermal management system further includes a fan configured to air-cool the condenser; wherein the processor is configured to turn on the fan when the thermal management system is in the fifth operating mode.

[0045] The fan accelerates heat exchange between the ambient airflow and the refrigerant flowing through the condenser, thereby improving cooling efficiency. The evaporator transfers cooling energy to the coolant flow path of the first liquid-cooled circulation loop through heat exchange. The first liquid-cooled circulation loop then transfers cooling energy to the second liquid-cooled circulation loop through the third heat exchanger, thus more effectively meeting the thermal management requirements of the battery and energy storage converter.

[0046] In one aspect of this disclosure, a control method for the aforementioned energy storage system is provided, comprising: operating the opening and closing states of the valve, the heater, and the refrigerant circulation loop according to the operating mode of the thermal management system.

[0047] In this embodiment, the opening and closing states of the valves, the heater, and the refrigerant circulation loop are operated according to the working mode of the thermal management system, which can satisfy the thermal management function played by the thermal management system in different working modes.

[0048] In some embodiments, the step of operating the opening and closing states of the valve, the heater, and the refrigerant circulation loop according to the operating mode of the thermal management system includes: when the thermal management system is in a first operating mode, opening the refrigerant circulation loop, closing the valve, and closing the heater.

[0049] In this embodiment, when the thermal management system is in the first working mode, the refrigerant circulation loop is turned on, the valve is closed, and the heater is turned off. This can make full use of the liquid cooling circulation bypass to assist the liquid cooling circulation loop and improve the cooling effect of the battery and energy storage converter, so as to meet the cooling requirements of the battery and energy storage converter.

[0050] In some embodiments, the control method further includes: in response to the temperature of the energy storage converter being greater than or equal to a first preset temperature T1, switching the thermal management system to the first operating mode.

[0051] In this embodiment, by comparing the energy storage converter with a threshold, the thermal management system switches to the first working mode, which can meet the situation where the energy storage converter has a high cooling demand. By utilizing the transfer of cooling capacity from the refrigerant circulation loop to the first liquid cooling circulation loop and from the first liquid cooling circulation loop to the second liquid cooling circulation loop, the cooling needs of the battery and the energy storage converter are met while saving the energy consumed by the refrigerant circulation system, which is beneficial to energy saving.

[0052] In some embodiments, the refrigerant circulation loop further includes a condenser, and the thermal management system further includes a fan configured to air-cool the condenser; wherein the control method further includes: turning on the fan when the thermal management system is in the first operating mode.

[0053] In this embodiment, the fan can improve the condensing efficiency of the condenser and enhance the cooling capacity of the refrigerant circulation loop in the first operating mode, thereby improving the cooling effect of the battery and energy storage converter.

[0054] In some embodiments, the step of operating the opening and closing states of the valve, the heater, and the refrigerant circulation loop according to the operating mode of the thermal management system includes: when the thermal management system is in a second operating mode, closing the refrigerant circulation loop, opening the valve, and closing the heater.

[0055] In this embodiment, the liquid cooling circulation bypass is in the conducting state in the second working mode. At this time, the cooling or heat absorbed by the coolant flowing through the liquid cooling circulation bypass is provided to the battery when it flows back to the first liquid cooling circulation loop, and is transferred to the second liquid cooling circulation loop through heat exchange, which helps to meet the thermal management requirements of the battery and the energy storage converter.

[0056] In some embodiments, the control method further includes: in response to an ambient temperature being less than or equal to a second preset temperature T2, switching the thermal management system to the second operating mode.

[0057] In this embodiment, by comparing the ambient temperature with a threshold, the thermal management system switches to the second operating mode. When the ambient temperature is low, the refrigerant circulation loop and heater are shut down, and the liquid cooling circulation bypass absorbs the cold energy from the environment, allowing the battery and energy storage converter to be cooled by natural cooling. The first pump in the first liquid cooling circulation loop drives the coolant into the liquid cooling circulation bypass, eliminating the need for additional drive components and shutting down the refrigerant circulation system, thereby saving energy to a greater extent.

[0058] In some embodiments, the fourth heat exchanger includes a coolant heat dissipation container, and the thermal management system further includes a fan configured to air-cool the coolant heat dissipation container; wherein the control method further includes: turning on the fan when the thermal management system is in the second operating mode.

[0059] With the help of the fan, the cooler ambient airflow can be accelerated to exchange heat with the coolant flowing through the coolant heat dissipation container, transferring the coldness from the environment to the liquid cooling circulation bypass, and then to the first liquid cooling circulation loop through the coolant. The first liquid cooling circulation loop transfers the coldness to the second liquid cooling circulation loop through the third heat exchanger, thereby effectively utilizing the natural coldness in the environment to meet the thermal management requirements of the battery and energy storage converter while reducing system energy consumption.

[0060] In some embodiments, the step of operating the opening and closing states of the valve, the heater, and the refrigerant circulation loop according to the operating mode of the thermal management system includes: when the thermal management system is in a third operating mode, closing the refrigerant circulation loop, closing the valve, and turning on the heater.

[0061] In this embodiment, when the thermal management system is in the third operating mode, the refrigerant circulation loop is closed, the valve is closed, and the heater is turned on. The heating effect of the heater can be used to increase the temperature of the coolant entering the first heat exchanger, thereby increasing the battery temperature and improving battery performance, energy consumption, and efficiency. Moreover, by closing the second valve, the coolant does not need to be cooled through the liquid cooling circulation bypass, thus avoiding increasing the heating load on the heater.

[0062] In some embodiments, the control method further includes: in response to the temperature of the battery being less than or equal to a third preset temperature T3 and the temperature of the coolant in the upstream flow path of the first liquid cooling circulation loop being less than a fourth preset temperature T4, the thermal management system is switched to the third operating mode, wherein the third preset temperature T3 is lower than the fourth preset temperature T4.

[0063] In this embodiment, by comparing the battery temperature and coolant temperature with respect to threshold values, the thermal management system can switch to the third operating mode to meet the heating requirements of the battery when its temperature is low. Furthermore, since the coolant itself is at a low temperature, a heater is used to raise its temperature, ensuring smooth battery heating. Moreover, the coolant used for battery heating can meet the cooling requirements of the energy storage converter, which has a higher temperature.

[0064] In some embodiments, the step of operating the opening and closing states of the valve, the heater, and the refrigerant circulation loop according to the operating mode of the thermal management system includes: when the thermal management system is in a fourth operating mode, closing the refrigerant circulation loop, closing the valve, and closing the heater.

[0065] In this embodiment, by comparing the battery temperature and coolant temperature with respect to threshold values, the thermal management system can save energy to a greater extent when switching to the fourth operating mode. The temperature difference between the battery and the energy storage converter is used to heat the battery and cool the energy storage converter through the circulation and heat exchange of the coolant.

[0066] In some embodiments, the control method further includes: in response to the temperature of the battery being less than or equal to a third preset temperature T3, and the temperature of the coolant in the upstream flow path of the first liquid cooling circulation loop being greater than or equal to a fourth preset temperature T4 and less than or equal to a fifth preset temperature T5, the thermal management system is switched to the fourth operating mode, wherein the fourth preset temperature T4 is greater than the third preset temperature T3, and the fifth preset temperature T5 is greater than the fourth preset temperature T4.

[0067] In this embodiment, by comparing the battery temperature and coolant temperature with threshold values, the thermal management system switches to the fourth operating mode. This mode addresses the issue of low battery temperatures and high coolant temperatures. When the battery temperature is low and the coolant temperature is high, the system can meet the heating needs of the battery, improving battery performance, energy consumption, and efficiency. Furthermore, it eliminates the need for a heater when the coolant temperature is high, thus saving energy. Additionally, the coolant recovers heat through heat exchange with the energy storage converter and transfers it to the battery to raise its temperature.

[0068] In some embodiments, the step of operating the opening and closing states of the valve, the heater, and the refrigerant circulation loop according to the operating mode of the thermal management system includes: opening the refrigerant circulation loop, closing the valve, and closing the heater when the thermal management system is in a fifth operating mode; and closing the refrigerant circulation loop, closing the valve, and closing the heater when the thermal management system is in a sixth operating mode.

[0069] When the coolant temperature is high, it is difficult to effectively cool the battery through the first heat exchanger and the energy storage converter through the second heat exchanger. Therefore, in this embodiment, when the thermal management system is in the fifth operating mode, the refrigerant circulation loop is opened, the valve is closed, and the heater is turned off, allowing the coolant to cool down through heat exchange with the refrigerant in the circulation loop, thereby more effectively cooling the battery and the energy storage converter. Moreover, by closing the valve, the coolant does not need to bypass the liquid cooling circulation and instead flows directly through the heat exchange pipe for heat exchange with the refrigerant, which helps to improve the heat exchange efficiency of the evaporator. When the coolant temperature is raised, the thermal management system can operate in the sixth operating mode, in which the refrigerant circulation loop is closed, the valve is closed, and the heater is turned off, saving energy consumed by the refrigerant circulation loop.

[0070] In some embodiments, the control method further includes: in response to the battery temperature being less than or equal to a third preset temperature T3, and the coolant temperature of the first liquid cooling circulation loop located in the upstream flow path of the first heat exchanger being greater than a fifth preset temperature T5, causing the thermal management system to switch to the fifth operating mode; in response to the thermal management system being in the fifth operating mode, and the coolant temperature of the first liquid cooling circulation loop located in the upstream flow path of the first heat exchanger being less than a fourth preset temperature T4, causing the thermal management system to switch to the sixth operating mode; wherein the fifth preset temperature T5 is greater than the fourth preset temperature T4, and the fourth preset temperature T4 is greater than the third preset temperature T3.

[0071] In this embodiment, by comparing the battery temperature and coolant temperature with a threshold, when the thermal management system switches to the fifth working mode, it can efficiently cool the battery and the energy storage converter by means of a refrigerant circulation loop that exchanges heat with the coolant when the coolant temperature is high. The cooling requirements of the battery and the energy storage converter can be met, and the refrigerant circulation loop is shut off after the coolant temperature is reduced to a certain level, thereby saving energy consumption.

[0072] In some embodiments, the refrigerant circulation loop further includes a condenser, and the thermal management system further includes a fan configured to air-cool the condenser; wherein the control method further includes turning on the fan when the thermal management system is in the fifth operating mode.

[0073] The fan accelerates heat exchange between the ambient airflow and the refrigerant flowing through the condenser, thereby improving cooling efficiency. The evaporator transfers cooling energy to the coolant flow path of the first liquid-cooled circulation loop through heat exchange. The first liquid-cooled circulation loop then transfers cooling energy to the second liquid-cooled circulation loop through the third heat exchanger, thus more effectively meeting the thermal management requirements of the battery and energy storage converter. Attached Figure Description

[0074] The accompanying drawings, which form part of this specification, illustrate embodiments of this disclosure and, together with the specification, serve to explain the principles of this disclosure.

[0075] This disclosure will become clearer with reference to the accompanying drawings and the following detailed description, wherein:

[0076] Figure 1 is a schematic diagram of the structure of some embodiments of the energy storage system according to the present disclosure;

[0077] Figure 2 is a structural schematic diagram of some other embodiments of the energy storage system according to the present disclosure;

[0078] Figure 3 is a schematic diagram of the structure of the thermal management system according to an embodiment of the energy storage system of this disclosure;

[0079] Figure 4 is a schematic diagram of the structure of the thermal management system according to some other embodiments of the energy storage system of the present disclosure;

[0080] Figure 5 is a schematic diagram of the structure of the thermal management system according to some other embodiments of the energy storage system of the present disclosure;

[0081] Figure 6 is a schematic diagram of control signal connections according to an embodiment of the energy storage system of this disclosure;

[0082] Figure 7 is a schematic diagram of the medium circulation in the first working mode of the thermal management system according to an embodiment of the energy storage system thermal management system of the present disclosure;

[0083] Figure 8 is a schematic diagram of the medium circulation in the thermal management system when the thermal management system is in the second working mode according to an embodiment of the energy storage system of the present disclosure;

[0084] Figure 9 is a schematic diagram of the medium circulation in the thermal management system when the thermal management system is in the third working mode according to an embodiment of the energy storage system of the present disclosure;

[0085] Figure 10 is a schematic diagram of the medium circulation in the thermal management system when the thermal management system is in the fourth working mode according to an embodiment of the energy storage system of the present disclosure;

[0086] Figure 11 is a schematic diagram of the medium circulation in the thermal management system when the thermal management system is in the fifth working mode according to an embodiment of the energy storage system of the present disclosure;

[0087] Figure 12 is a schematic diagram of the medium circulation in the thermal management system under the sixth working mode of the thermal management system according to an embodiment of the energy storage system of the present disclosure.

[0088] It should be understood that the dimensions of the various parts shown in the accompanying drawings are not drawn to actual scale. Furthermore, the same or similar reference numerals denote the same or similar components.

[0089] The reference numerals in the attached diagrams represent: 10-Energy storage system; 11-Thermal management system; 111-Third heat exchanger; 112-Fan; 12-Battery; 13-Power Conversion System (PCS); 14-Casing; 20-First liquid cooling circulation loop; 21-First heat exchanger; 22-Heater; 23-Coolant flow path; 24-First pump; 25-First expansion tank; 26-First sensor; 27-Second sensor; 30-Second liquid cooling circulation loop; 31-Second heat exchanger; 32-Second pump; 33-Second expansion tank; 40-Refrigerant circulation loop; 41-Compressor; 42-Condenser; 43-Throttling device; 44-Evaporator; 45-Liquid receiver; 46-First pressure sensor; 47-Second pressure sensor; 50-Liquid cooling circulation bypass; 51-Fourth heat exchanger; 511-Coolant heat dissipation container; 52-Valve; 60 - Processor; fd - Airflow direction; M1 - First working mode; M2 - Second working mode; M3 - Third working mode; M4 - Fourth working mode; M5 - Fifth working mode; M6 - Sixth working mode. Detailed Implementation

[0090] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The descriptions of the exemplary embodiments are merely illustrative and are in no way intended to limit the present disclosure or its application or use. The present disclosure may be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that the present disclosure will be thorough and complete, and will fully express the scope of the disclosure to those skilled in the art. It should be noted that, unless specifically stated otherwise, the relative arrangement of components and steps, the composition of materials, numerical expressions, and values ​​set forth in these embodiments should be interpreted as exemplary only and not as limiting.

[0091] The terms "first," "second," and similar words used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. Words such as "including" or "contains" mean that the element preceding the word encompasses the element listed after it, and do not exclude the possibility of encompassing other elements as well. Terms such as "above," "below," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, this relative positional relationship may also change accordingly.

[0092] The embodiments of this disclosure will be further described in detail below with reference to the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of this disclosure by way of example, but should not be used to limit the scope of this disclosure, that is, this disclosure is not limited to the described embodiments.

[0093] In the description of this disclosure, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," etc., indicating orientation or positional relationships are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. "Vertical" is not vertical in the strict sense, but within the allowable tolerance range. "Parallel" is not parallel in the strict sense, but within the allowable tolerance range.

[0094] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of this disclosure. It should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this disclosure based on the specific circumstances.

[0095] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, features in the following embodiments can be combined with each other.

[0096] In this disclosure, "multiple" means two or more (including two).

[0097] In this embodiment of the disclosure, the energy storage system may include an energy storage device and an energy storage converter. The energy storage device may include one or more batteries for storing electrical energy, and its structure may be an energy storage container, an energy storage cabinet, etc. The batteries in the energy storage device can be used to store surplus electrical energy during off-peak hours in the power system to supplement electricity consumption during peak hours.

[0098] Energy storage converters control the charging and discharging processes of batteries, converting AC to DC power, and can directly supply power to AC loads even without a power grid. An energy storage converter may include a DC / AC bidirectional converter and a controller. The controller receives control commands from the backend via communication and controls the converter to charge or discharge the battery according to the sign and magnitude of the power command, thereby regulating the active and reactive power of the power grid. The controller can communicate with the battery's battery management system (BMS) via a bus interface to obtain battery status information, enabling protective charging and discharging of the battery and improving battery operation safety.

[0099] In this embodiment of the disclosure, a battery refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity. A battery cell is the smallest unit constituting a battery. A battery cell includes electrode components capable of undergoing electrochemical reactions. A battery cell can be a rechargeable battery, meaning a battery cell that can be recharged after discharge to activate its active materials and continue to be used.

[0100] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments disclosed herein are not limited to this.

[0101] In some embodiments, the battery may include a housing and individual battery cells, with the individual battery cells housed within the housing. The housing may be made of metal, non-metal, or a combination of materials. Multiple individual battery cells may be arranged along at least one of the length and width directions of the housing. At least one row or column of battery cells may be provided as needed. Alternatively, one or more layers of battery cells may be provided along the height direction of the battery, as required.

[0102] The individual battery cells are electrically connected, such as in series, parallel, or a combination thereof, to achieve the desired electrical performance parameters. A combination thereof refers to multiple battery cells being connected in both series and parallel configurations. Adjacent battery cells can be electrically connected via busbars. Multiple battery cells can be arranged in rows; one or more rows of battery cells can be installed within the enclosure as needed. The enclosure can be made of metal, non-metal, or a mixture of materials.

[0103] In some embodiments, the battery may include a housing and a battery module, the housing providing a space for the battery module, which is installed inside the housing. Multiple battery cells may first be connected in series, parallel, or in a mixed configuration to form a battery module, and then the multiple battery modules may be connected in series, parallel, or in a mixed configuration to form a whole, which is then housed inside the housing.

[0104] In some embodiments, the battery cell includes an electrode assembly, a housing, and an end cap. The housing has a receiving cavity for receiving the electrode assembly and an open end communicating with the receiving cavity. The end cap closes to the open end.

[0105] The electrode assembly may include a first electrode and a second electrode with opposite polarities, and a separator disposed between the first electrode and the second electrode. In some embodiments, the first electrode is a positive electrode and the second electrode is a negative electrode. In other embodiments, the first electrode is a negative electrode and the second electrode is a positive electrode. During the charging and discharging of a single battery cell, active ions (e.g., lithium ions) repeatedly insert and extract between the positive and negative electrode. The separator, disposed between the positive and negative electrode, serves to prevent short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0106] In some embodiments, the positive electrode may include a positive current collector substrate and a positive active material layer disposed on at least one surface of the positive current collector substrate.

[0107] As an example, the positive electrode current collector substrate has two surfaces opposite each other in its own thickness direction, and the positive electrode active material layer is disposed on either or both of the two opposite surfaces of the positive electrode current collector substrate.

[0108] As an example, the positive electrode current collector substrate can be a metal foil or a composite current collector. For example, as a metal foil, silver-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium, etc., can be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by applying a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) onto a polymer material base material (such as a polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc. base material).

[0109] As an example, the positive electrode active material layer may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this disclosure is not limited to these materials, and other conventional materials that can be used as positive electrode active material layers in batteries may also be used. These positive electrode active material layers may be used alone or in combination of two or more. Examples of lithium phosphate include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxides include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05 At least one of O2 and its modified compounds.

[0110] In some embodiments, the negative electrode sheet may include a negative current collector substrate.

[0111] As an example, the negative electrode current collector substrate can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, it can be silver-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium, etc. Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by applying a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) onto a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0112] In some embodiments, the negative electrode sheet may include a negative electrode current collector substrate and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector substrate.

[0113] As an example, the negative electrode current collector substrate has two surfaces opposite each other in its own thickness direction, and the negative electrode active material layer is disposed on either or both of the two opposite surfaces of the negative electrode current collector substrate.

[0114] As an example, the negative electrode active material layer may employ a type of negative electrode active material layer known in the art for use in battery cells. As an example, the negative electrode active material layer may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this disclosure is not limited to these materials, and other conventional materials that can be used as negative electrode active material layers in batteries may also be used. These negative electrode active material layers may be used alone or in combination of two or more.

[0115] In some embodiments, the positive electrode current collector substrate can be made of aluminum, and the negative electrode current collector substrate can be made of copper.

[0116] In some embodiments, the separator is a separator membrane. This disclosure does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0117] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a separate component located between the positive and negative electrode plates, or it can be located between the positive and negative electrode plates while being attached to the surface of the positive electrode plate and / or the surface of the negative electrode plate.

[0118] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrode plates, serving both to transport ions and to isolate the positive and negative electrodes.

[0119] In some embodiments, the battery cell further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This disclosure does not impose specific limitations on the type of electrolyte, which can be selected according to requirements. The electrolyte can be liquid, gel, or solid.

[0120] As an example, liquid electrolytes include electrolyte salts and solvents.

[0121] In some embodiments, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0122] In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0123] As an example, gel electrolytes include a polymer-based backbone network combined with an ionic liquid—a lithium salt.

[0124] As an example, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0125] As an example, polymer solid electrolytes can be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0126] As an example, inorganic solid electrolytes can be one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphate sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0127] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0128] In some embodiments, the electrode assembly includes a main body. The main body can be a wound structure formed by winding a positive electrode, a negative electrode, and a separator, or a stacked structure formed by overlapping positive electrode, negative electrode, and a separator. One or more positive and negative electrode sheets can be provided respectively. As an example, multiple positive electrode sheets and multiple negative electrode sheets are alternately arranged along the electrode thickness direction.

[0129] In some embodiments, the main body may be cylindrical, flat, or polygonal. The ends of the main body may be provided with a first tab and a second tab. The first tab can be formed by cutting or trimming the current collector substrate of the first electrode, or it can be welded to the side of the current collector substrate of the first electrode. The second tab can be formed by cutting or trimming the current collector substrate of the second electrode, or it can be welded to the side of the current collector substrate of the second electrode.

[0130] In an embodiment where the first electrode is a positive electrode and the second electrode is a negative electrode, the first electrode includes a positive electrode tab serving as a first electrode tab, and the second electrode includes a negative electrode tab serving as a second electrode tab. In an embodiment where the first electrode is a negative electrode and the second electrode is a positive electrode, the first electrode includes a negative electrode tab serving as a first electrode tab, and the second electrode includes a positive electrode tab serving as a second electrode tab.

[0131] The housing is used to encapsulate electrode components and electrolytes. The housing can be made of steel, aluminum, or composite metals (such as a copper-aluminum composite housing).

[0132] As an example, a battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries.

[0133] A pressure relief component may be provided on the end cap. A pressure relief component is an element or part that is activated to release internal pressure or temperature when the internal pressure or temperature of a battery cell reaches a predetermined threshold. This threshold design varies depending on design requirements. The threshold may depend on one or more materials of the positive electrode, negative electrode, electrolyte, and separator in the battery cell. The pressure relief component can take the form of an explosion-proof valve, gas valve, pressure relief valve, or safety valve, and can specifically employ pressure-sensitive or temperature-sensitive elements or structures. That is, when the internal pressure or temperature of the battery cell reaches the predetermined threshold, the pressure relief component actuates or a weak structure within the pressure relief component is damaged, thereby forming an opening or channel for the release of internal pressure or temperature.

[0134] In the event of thermal runaway or other adverse reactions in the electrode assembly, the resulting high-temperature, high-pressure gas will enter the pressure relief chamber. This gas may also contain active materials. When the pressure inside the pressure relief chamber pr exceeds the design threshold, the pressure relief section 50 releases the internal pressure, discharging emissions from the battery cells. Emissions from the battery cells mentioned here include, but are not limited to: electrolyte, dissolved or broken positive and negative electrode plates, fragments of the separator, high-temperature, high-pressure gases generated during the reaction (such as CH4, CO, and other combustible gases), flames, etc.

[0135] In some related technologies, to meet the cooling requirements of batteries and power converters (PCS) in energy storage systems, the thermal management system uses liquid cooling for batteries and air cooling for PCS, or employs two independent liquid cooling systems to cool the batteries and PCS separately. This type of thermal management system suffers from large size and weight, and relatively low energy efficiency.

[0136] To improve the size, weight, and energy efficiency of thermal management systems, some related technologies employ a series cooling medium loop to cool the battery pack and energy storage converter. Research has found that the cooling effect of the upstream battery pack in this thermal management system can affect the cooling of the downstream energy storage converter, making it difficult to independently manage the thermal of the battery and the PCS to meet different thermal management requirements.

[0137] In view of this, the present disclosure provides an energy storage system and its control method, which is beneficial to meeting the different thermal management requirements of batteries and energy storage converters in the energy storage system.

[0138] In one aspect of this disclosure, an energy storage system is provided, comprising:

[0139] Batteries are used to store and release energy;

[0140] An energy storage converter is used to connect the power supply source and the battery; and

[0141] Thermal management system;

[0142] The thermal management system includes:

[0143] The first liquid cooling circulation loop includes a first heat exchanger for exchanging heat with the battery;

[0144] The second liquid-cooled circulation loop includes a second heat exchanger for heat exchange with the energy storage converter; and

[0145] A third heat exchanger, connected to both the first and second liquid cooling circulation loops, is configured to achieve heat exchange between the coolant in the first and second liquid cooling circulation loops.

[0146] In this embodiment, a first heat exchanger that exchanges heat with the battery and a second heat exchanger that exchanges heat with the energy storage converter are respectively located in a first liquid cooling loop and a second liquid cooling loop. The first and second liquid cooling loops exchange heat between the coolant via a third heat exchanger. This structure, which places the first and second heat exchangers in different liquid cooling loops, allows for independent configuration and control based on the thermal management requirements of the battery and the energy storage converter, thus meeting more flexible thermal management needs. Furthermore, the third heat exchanger transfers the coolant from the lower-temperature first liquid cooling loop (which exchanges heat with the battery) to the second liquid cooling loop to cool the higher-temperature energy storage converter. Conversely, the third heat exchanger also transfers heat from the higher-temperature second liquid cooling loop (which exchanges heat with the energy storage converter) to the first liquid cooling loop to heat the lower-temperature battery.

[0147] Figure 1 is a structural schematic diagram of some embodiments of the energy storage system according to the present disclosure. Figure 2 is a structural schematic diagram of other embodiments of the energy storage system according to the present disclosure. Figure 3 is a structural schematic diagram of the thermal management system in an embodiment of the energy storage system according to the present disclosure.

[0148] Referring to Figures 1-3, this disclosure provides an energy storage system including a thermal management system 11, a battery 12, and an energy storage converter 13. The battery 12 is used to store and release energy, and the energy storage converter 13 is used to connect a power supply source and the battery 12. The thermal management system 11 includes a first liquid cooling loop 20, a second liquid cooling loop 30, and a third heat exchanger 111. The first liquid cooling loop 20 includes a first heat exchanger 21 for heat exchange with the battery 12. The second liquid cooling loop 30 includes a second heat exchanger 31 for heat exchange with the energy storage converter 13. The third heat exchanger 111 is connected to both the first liquid cooling loop 20 and the second liquid cooling loop 30 and is configured to achieve heat exchange between the coolant in the first liquid cooling loop 20 and the coolant in the second liquid cooling loop 30.

[0149] The power supply source may include the power grid or power generation equipment. The energy storage converter 13 has a DC side and an AC side. The DC side is used to connect to the battery 12, and the AC side is used to connect to the power supply source. When the battery 12 is charging, the energy storage converter 20 acts as a rectifier to convert the AC power from the grid on the AC side into DC power and store it in the battery 12. When the battery 12 is discharging, the energy storage converter 20 acts as an inverter to convert the DC power from the DC side into AC power and supply it to the grid.

[0150] The thermal management system 11 can be used to perform thermal management on components in an energy storage system, including the battery 12 and the energy storage inverter 13, such as cooling or heating the battery 12 and cooling the energy storage inverter 13. The thermal management system 11 can be connected to the battery 12 and the energy storage inverter 13 to achieve thermal management of the battery 12 and the energy storage inverter 13.

[0151] The coolant flowing in the first liquid cooling circulation loop 20 and the second liquid cooling circulation loop 30 can be water, water-containing coolant, or waterless coolant, etc.

[0152] The first heat exchanger 21 is disposed in and is part of the first liquid cooling circulation loop 20. The coolant flowing in the first liquid cooling circulation loop 20 can exchange heat with the battery 12 in the first heat exchanger 21. The first heat exchanger 21 can transfer heat to the battery 12 by means of, but not limited to, thermal conduction. For example, the first heat exchanger 21 may include a cooling plate in contact with the battery 12.

[0153] The second heat exchanger 31 is disposed in the second liquid cooling circulation loop 30 and is part of the second liquid cooling circulation loop 30. The coolant flowing in the second liquid cooling circulation loop 30 can exchange heat with the energy storage converter 13 in the second heat exchanger 31. The second heat exchanger 31 can transfer heat to the energy storage converter 13 by means of, but not limited to, thermal conduction. For example, the second heat exchanger 31 may include a cooling plate in contact with the energy storage converter 13.

[0154] Referring to Figure 3, the two dashed lines within the heat exchanger 111 indicate two non-connected pipes installed inside the third heat exchanger 111. One pipe connects to the first liquid-cooled circulation loop 20, allowing the coolant in the first liquid-cooled circulation loop 20 to flow through it. The other pipe connects to the second liquid-cooled circulation loop 30, allowing the coolant in the second liquid-cooled circulation loop 30 to flow through it. The coolant flowing in these two pipes can exchange heat within the third heat exchanger 111, thereby achieving heat transfer between the first liquid-cooled circulation loop 20 and the second liquid-cooled circulation loop 30. The third heat exchanger can be a plate heat exchanger, or other types of heat exchangers, such as a tube heat exchanger or a tube-plate heat exchanger.

[0155] In some energy storage systems, the temperature tolerance of battery 12 is lower than that of energy storage inverter 13; for example, the highest temperature that battery 12 can withstand is lower than the highest temperature that energy storage inverter 13 can withstand. Furthermore, excessively low temperatures of battery 12 can also affect its normal operation to some extent, while energy storage inverter 13 can operate normally. Therefore, battery 12 and energy storage inverter 13 in the energy storage system have different thermal management requirements.

[0156] In this embodiment, a first heat exchanger that exchanges heat with the battery and a second heat exchanger that exchanges heat with the energy storage converter are respectively located in a first liquid cooling loop and a second liquid cooling loop. The first and second liquid cooling loops exchange heat between the coolant via a third heat exchanger. This structure, which places the first and second heat exchangers in different liquid cooling loops, allows for independent configuration and control based on the thermal management requirements of the battery and the energy storage converter, thus meeting more flexible thermal management needs. Furthermore, the third heat exchanger transfers the coolant from the lower-temperature first liquid cooling loop (which exchanges heat with the battery) to the second liquid cooling loop to cool the higher-temperature energy storage converter. Conversely, the third heat exchanger also transfers heat from the higher-temperature second liquid cooling loop (which exchanges heat with the energy storage converter) to the first liquid cooling loop to heat the lower-temperature battery.

[0157] Referring to FIG3, in some embodiments, the thermal management system 11 further includes a heater 22. The heater 22 is disposed in the first liquid cooling circulation loop 20 and is configured to heat the coolant flowing into the first heat exchanger 21.

[0158] Heater 22 can be an electric heater, a steam heater, or any other available heater. For example, heater 22 can be a safe and efficient positive temperature coefficient (PTC) heater.

[0159] In this embodiment, by placing the heater 33 in the first liquid cooling circulation loop 20, the coolant flowing through the heater 33 in the first liquid cooling circulation loop 20 can be heated to increase the temperature of the coolant before flowing into the first heat exchanger 21, thereby increasing the temperature of the battery 12 through the first heat exchanger 21 when the battery 12 temperature is low.

[0160] In Figure 3, the first liquid cooling circulation loop 20 may further include a first pump 24, a first expansion tank 25, and a first sensor 26 and a second sensor 27 for sensing parameters such as temperature and pressure. The arrows in Figure 2 indicate the flow direction of the coolant in the first liquid cooling circulation loop 20 driven by the first pump 24. The first expansion tank 25 can compensate for the volume expansion or contraction of the coolant in the first liquid cooling circulation loop 20 due to temperature changes and can maintain the pressure stability of the first liquid cooling circulation loop 20.

[0161] The first sensor 26 can be located upstream of the heater 22 to sense parameters such as the temperature and pressure of the coolant before it enters the first heat exchanger 21 or the heater 22. The second sensor 27 can be located downstream of the first heat exchanger 21 to sense parameters such as the temperature and pressure of the coolant after it enters the first heat exchanger.

[0162] The second liquid cooling circulation loop 30 in Figure 3 may also include a second pump 32 and a second expansion tank 33. The arrows in Figure 2 also indicate the flow direction of the coolant in the second liquid cooling circulation loop 30 driven by the second pump 32. The second expansion tank 33 can compensate for the volume expansion or contraction of the coolant in the second liquid cooling circulation loop 30 due to temperature changes, and can maintain the pressure stability of the second liquid cooling circulation loop 30.

[0163] Referring to Figure 2, in some embodiments, the energy storage system 10 further includes a housing 14. The battery 12 is located inside the housing 14, and the energy storage converter 13 is located outside the housing 14.

[0164] Figure 2 shows that the enclosure 14, the battery 12, and portions of the piping and components in the thermal management system 11 related to the thermal management of the battery 12 are located within the housing space formed by the enclosure 14. The energy storage converter 13 and portions of the piping and components in the thermal management system 11 related to the thermal management of the pure energy converter 13 are located outside the housing space formed by the enclosure 14. The enclosure 14 can be in the form of a container or electrical cabinet, and its material can be metal, alloy, or non-metal. The enclosure 14 can accommodate one or more batteries 13.

[0165] In this embodiment, the energy storage converter 13 is located outside the housing 14 that houses the batteries 12. This allows the housing 14 to accommodate a larger number of batteries 12, thereby increasing the capacity of the energy storage system 10. In addition, the energy storage converter 13 located outside the housing 14 is also more convenient to maintain, as maintenance can be performed without opening the housing 14.

[0166] In other embodiments, the energy storage converter 13 may also be located within the housing 14. For example, the energy storage converter 13 may be housed within the housing 14 and located in the same or a different compartment from the battery 13.

[0167] Figure 4 is a schematic diagram of the structure of the thermal management system according to some other embodiments of the energy storage system of this disclosure.

[0168] Referring to Figure 4, in some embodiments, the thermal management system 11 further includes a refrigerant circulation loop 40. The refrigerant circulation loop 40 includes an evaporator 44; wherein the refrigerant circulation loop 40 is configured to circulate refrigerant. A first liquid-cooled circulation loop 20 has a coolant flow path 23 passing through the evaporator 44, and the refrigerant in the refrigerant circulation loop 40 exchanges heat with the coolant flow path 23 through the evaporator 44.

[0169] The refrigerant circulation loop 40 enables the circulation of refrigerant fluid. Since this circulation is typically achieved through the compression of the refrigerant by a compressor, it is also called a compression refrigeration cycle. In this refrigerant circulation loop 40, heat transfer is achieved through the condensation and evaporation of the refrigerant fluid. The refrigerant may include, but is not limited to, water, ammonia, carbon dioxide, and halogenated hydrocarbon refrigerants. The refrigerant in the refrigerant circulation loop 40 operates independently of the coolant in the first liquid-cooled circulation loop 20, and heat transfer is achieved through heat exchange.

[0170] The coolant flow path 23 passes through the evaporator 44, where it can exchange heat with the refrigerant flowing through the evaporator 44. The evaporator 44 absorbs heat, thus cooling the coolant flowing in the coolant flow path 23. In Figure 4, the coolant flow path 23 is shown as a dashed line within the evaporator 44. This coolant flow path 23 can be located downstream of the first pump 24 and connected in parallel with the pipe connecting the first liquid cooling circulation loop 20 in the third heat exchanger 111. The evaporator 44 can be a plate heat exchanger evaporator or other types of evaporators, such as a shell-and-tube evaporator.

[0171] In this embodiment, heat exchange between the refrigerant circulation loop 40 and the first liquid cooling circulation loop 20 provides cooling or heating to the coolant in the first liquid cooling circulation loop 20, which helps improve the thermal management efficiency of the first liquid cooling circulation loop 20 and increases the configuration flexibility for different thermal management needs. Furthermore, refrigerant circulation is achieved through the refrigerant circulation loop 40, and heat exchange occurs between the evaporator 44 and the first liquid cooling circulation loop 20 through the coolant flow path 23 of the evaporator 44, thereby effectively reducing the temperature of the coolant flowing in the first liquid cooling circulation loop 20 and meeting the cooling requirements of the thermal management system.

[0172] In Figure 4, the refrigerant circulation loop 40 may further include a compressor 41, a condenser 42, and a throttling device 43. Arrows in the refrigerant circulation loop 40 indicate the flow direction of the refrigerant driven by the compressor 41. The compressor 41 compresses the low-temperature, low-pressure gaseous refrigerant from the evaporator 44 into a high-temperature, high-pressure gaseous refrigerant. The condenser 42 cools the high-temperature, high-pressure gaseous refrigerant output from the compressor 41 by releasing heat, at least partially converting it into a liquid state. The throttling device 43 may include a capillary tube, a thermostatic expansion valve, or an electronic expansion valve, which cools and depressurizes the refrigerant output from the condenser 42 by throttling. The evaporator 44 absorbs heat to raise the temperature of the refrigerant passing through the throttling device 43, at least partially converting it into a gaseous state.

[0173] Additionally, in Figure 4, the thermal management system 11 may also include a fan 112, which can provide air cooling for the condenser 42 to improve its efficiency. The fan 112 may include axial, centrifugal, or mixed-flow fans. A first pressure sensor 46 for sensing the intake pressure of the compressor 41 and a second pressure sensor 47 for sensing the discharge pressure of the compressor 41 may also be installed in the refrigerant circulation loop 40. The refrigerant circulation loop 40 in Figure 4 may also include a receiver 45, which can store excess refrigerant and adjust the refrigerant flow rate in the refrigerant circulation loop 40 according to changes in system load.

[0174] Figure 5 is a schematic diagram of the structure of the thermal management system according to some other embodiments of the energy storage system of this disclosure.

[0175] Referring to Figure 5, in some embodiments, the thermal management system 11 further includes a liquid cooling circulation bypass 50. The liquid cooling circulation bypass 50 is connected in parallel with the coolant flow path 23.

[0176] By connecting the liquid cooling circulation bypass 50 in parallel with the coolant flow path 23, when the liquid cooling circulation bypass 50 is open, under the driving action of the first pump 24, a portion of the coolant in the first liquid cooling circulation loop 20 flows through the liquid cooling circulation bypass 50 and then returns to the first liquid cooling circulation loop 20. This portion of coolant can be further heated or cooled by components installed in the liquid cooling circulation bypass 50. Accordingly, the thermal management system, which includes both the refrigerant circulation loop 40 and the liquid cooling circulation bypass 50, has greater configuration flexibility and can meet more diverse thermal management needs.

[0177] Referring to Figure 5, in some embodiments, the liquid cooling circulation bypass 50 includes a fourth heat exchanger 51 and a valve 52. The fourth heat exchanger 51 is configured to dissipate heat from the coolant flowing through the liquid cooling circulation bypass 50, and the valve 52 is connected in series with the fourth heat exchanger 51 and is configured to operate the on / off state of the liquid cooling circulation bypass 50.

[0178] A fourth heat exchanger 51 is installed in the liquid cooling circulation bypass 50, allowing the coolant flowing in the liquid cooling circulation bypass 50 to exchange heat in the fourth heat exchanger 51 via air cooling, liquid cooling, or other methods. For example, the fourth heat exchanger 51 may include a coolant heat dissipation container 511, which dissipates heat from the coolant via air cooling. The valve 52 can be an electrically, hydraulically, or manually controlled valve, such as a ball valve, butterfly valve, or diaphragm valve. The valve 52 can open or close the liquid cooling circulation bypass 50. As needed, the valve 52 can also control the flow rate of the liquid cooling circulation bypass 50.

[0179] In this embodiment, by setting a valve 52 in the liquid cooling circulation bypass 50, the valve 52 is used to open and close the liquid cooling circulation bypass 50, so that the coolant in the first liquid cooling circulation loop 20 is partially diverted to the liquid cooling circulation bypass 50 for heat exchange as needed, or is not diverted to the liquid cooling circulation bypass 50 for heat exchange, thereby increasing the controllability of the thermal management system.

[0180] Referring to Figure 5, in some embodiments, the refrigerant circulation loop 40 further includes a condenser 42, and the fourth heat exchanger 51 includes a coolant heat dissipation container 511 disposed adjacent to the condenser 42. The thermal management system 11 further includes a fan 112. The fan 112 is configured to provide air cooling for the condenser 42 and the coolant heat dissipation container 511.

[0181] The coolant heat dissipation container 511 is placed in the airflow path driven by the fan 112 so that the fan 112 can perform air cooling on the coolant heat dissipation container 511, thereby effectively improving the air cooling efficiency.

[0182] In Figure 5, the arrows in the liquid cooling circulation bypass 50 indicate the flow direction of the coolant under the drive of the pump 36, and the arrows on both sides of the fan 112 indicate the airflow direction. The two ends of the liquid cooling circulation bypass 50 can be connected to the two ends of the coolant flow path 23 respectively, forming a parallel connection with the coolant flow path 23.

[0183] Taking water or a water-containing coolant as an example, the coolant heat dissipation container 511 can be a radiator tank. The condenser 42 and the coolant heat dissipation container 511 can be arranged adjacently, either in a close-fitting manner or with a small gap. This adjacent arrangement also includes integrally forming at least a portion of the structure of the condenser 42 with at least a portion of the structure of the coolant heat dissipation container 511.

[0184] In this embodiment, by placing the condenser 42 adjacent to the coolant heat dissipation container 511, the fan 112 drives the airflow, allowing the condenser 42 and the coolant heat dissipation container 511 to be cooled by air simultaneously, which helps to improve air cooling efficiency and reduce energy consumption.

[0185] In other embodiments, the condenser 42 and the coolant heat dissipation container 511 may use different fans independently, or no fan may be provided for the coolant heat dissipation container 511 so that the coolant heat dissipation container 511 can dissipate heat naturally.

[0186] Referring to the airflow direction fd shown in Figure 5, in some embodiments, the coolant heat dissipation container 511 is located upstream of the condenser 42 along the airflow direction fd of the fan 45.

[0187] Generally, during the operation of the refrigerant circulation loop 40, the condenser 42 has a higher temperature than the coolant heat dissipation container 511. The airflow first passes through the coolant heat dissipation container 511 to cool it, absorbing heat and increasing its temperature. It then continues to absorb heat as it passes through the condenser 42, thus achieving the air cooling effect on the condenser 42. Therefore, by positioning the coolant heat dissipation container 511 upstream of the condenser 42 along the airflow direction fd of the fan 45, it is beneficial to balance the air cooling effects of both the coolant heat dissipation container 511 and the condenser 42.

[0188] Figure 6 is a schematic diagram of control signal connections according to an embodiment of the energy storage system of this disclosure.

[0189] Referring to Figures 5 and 6, in some embodiments, the thermal management system 11 further includes a heater 22 disposed in the first liquid cooling circulation loop 20. The energy storage system 10 also includes a processor 60. The processor 60 is configured to operate the opening and closing states of the valve 52, the heater 22, and the refrigerant circulation loop 40 according to the operating mode of the thermal management system 11.

[0190] The processor 60 can communicate with the valve 52, heater 22, and components in the refrigerant circulation loop 40 (such as compressor 41, throttling device 43, etc.) via wired or wireless means to receive data and issue commands. The processor 60 may include one or more processing units, which can be general-purpose processors, such as CPUs, digital signal processors, application-specific integrated circuits, field-programmable gate arrays or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components, capable of implementing or executing the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor.

[0191] The thermal management system may have one or more operating modes to meet the thermal management needs of the battery and energy storage converter in the energy storage system under different conditions. In some embodiments, the operating mode can be switched after a preset condition is met. In other embodiments, the operating mode can be switched by the operator through a mode command input via a panel or operating terminal.

[0192] In this embodiment, the processor 60 can operate the opening and closing states of the valve 52, the heater 22 and the refrigerant circulation loop 40 according to the working mode of the thermal management system 11, thereby satisfying the thermal management function played by the thermal management system 11 in different working modes.

[0193] In Figure 6, for an embodiment of the thermal management system 11 that includes a fan 112, the processor 60 can also be connected to the fan 112 via a signal to control the operation of the fan 112 according to the operating mode of the thermal management system 11, such as controlling the start, stop or power adjustment of the fan 112.

[0194] Figure 7 is a schematic diagram of the medium circulation in the first working mode of the thermal management system according to an embodiment of the energy storage system thermal management system of the present disclosure.

[0195] Referring to Figure 7, in some embodiments, the processor 60 is configured to: open the refrigerant circulation loop 40, close the valve 52, and close the heater 22 when the thermal management system 11 is in a first operating mode M1.

[0196] Figure 7 illustrates the media circulation and control relationship of the thermal management system in the first operating mode M1. In Figure 7, valve 52 is represented by a dashed line as being in the closed state. In this state, the closed valve 52 prevents coolant from flowing through the entire liquid cooling cycle bypass 50; correspondingly, the line of the liquid cooling cycle bypass 50 is not thickened. The lines of the first liquid cooling cycle loop 20, the second liquid cooling cycle loop 30, and the refrigerant cycle loop 40 are thickened to indicate coolant flow. Heater 22 is represented by a dashed line as being closed and not providing heating.

[0197] In the first operating mode M1, the first pump 24 drives the coolant to flow through a pipe of the third heat exchanger 111, and a portion of the coolant is diverted to the coolant flow path 23 before merging again and flowing to the heater 22. The coolant flows through the heater 22 into the first heat exchanger 21, at which point the heater 22 is turned off and does not provide heating. The coolant entering the first heat exchanger 21 exchanges heat with the battery 12 to meet the thermal management requirements of the battery 12. The coolant flowing out of the first heat exchanger 21 returns to the first pump 24, thus forming a coolant circulation loop in the first liquid cooling circuit 20.

[0198] The second pump 31 drives the coolant to another pipe of the third heat exchanger 111, where the coolant can exchange heat with the coolant in the first liquid-cooled circulation loop 20 through the third heat exchanger 51. The coolant enters the second heat exchanger 31 and exchanges heat with the energy storage converter 13 to meet the thermal management requirements of the energy storage converter 13. The coolant flowing out of the second heat exchanger 31 returns to the second pump 32, thus forming a circulation of coolant in the second liquid-cooled circulation loop 30.

[0199] In the first operating mode M1, the refrigerant circulation loop 40 is in operation. At this time, the compressor 41 is turned on and drives the refrigerant through the condenser 42, the throttling device 43, the liquid receiver 45, and the evaporator 44 before returning to the compressor 41. The refrigerant exchanges heat with the coolant in the coolant flow path 23 in the evaporator 44, thereby transferring the cooling capacity to the first liquid-cooled circulation loop 20.

[0200] The temperature of the coolant in the first liquid cooling circulation loop 20 after exchanging heat with the battery 12 is still relatively high compared to the energy storage converter 13. Therefore, the energy storage converter 13 can be cooled through heat exchange via the third heat exchanger 111.

[0201] In this embodiment, when the thermal management system 11 is in the first working mode M1, the processor 60 opens the refrigerant circulation loop 40, closes the valve 52, and closes the heater 22. The cooling capacity provided by the refrigerant circulation loop 40 can be transferred to the first liquid cooling circulation loop 20 through the evaporator 44, so as to improve the cooling effect of the battery 12 through the first heat exchanger 21. The cooling capacity in the first liquid cooling circulation loop 20 can also be transferred to the second liquid cooling circulation loop 30 through the third heat exchanger 111, so as to improve the cooling effect of the energy storage converter 13 through the second heat exchanger 31.

[0202] Referring to Figure 7, in some embodiments, the processor 60 is configured to switch the thermal management system 11 to the first operating mode M1 in response to the temperature of the energy storage converter 13 being greater than or equal to a first preset temperature T1.

[0203] The temperature of the energy storage converter 13 can be obtained by a temperature sensor built into the energy storage converter 13 or by a temperature sensor located outside the energy storage converter 13. The first preset temperature T1 is set in the range of [50℃, 80℃], and can be selected as 50℃, 58℃, 62℃, 65℃, 72℃ or 80℃, etc.

[0204] In this embodiment, by comparing the energy storage converter 13 with a threshold, the thermal management system 11 switches to the first operating mode M1, which can meet the situation where the energy storage converter 13 has a high cooling demand. By utilizing the transfer of cooling capacity from the refrigerant circulation loop 40 to the first liquid cooling circulation loop 20 and the transfer of cooling capacity from the first liquid cooling circulation loop 20 to the second liquid cooling circulation loop 30, the cooling needs of the battery 12 and the energy storage converter 13 are met while saving the energy consumed by the refrigerant circulation system 40, which is beneficial to energy saving.

[0205] In some embodiments, the refrigerant circulation loop 40 further includes a condenser 42, and the thermal management system 11 further includes a fan 112. The fan 112 is configured to provide air cooling for the condenser 42. The processor 60 is configured to turn on the fan 112 when the thermal management system 11 is in the first operating mode M1.

[0206] In Figure 7, the thickened lines of fan 112 indicate that fan 112 is in the on state.

[0207] In this embodiment, the fan 112 can improve the condensing efficiency of the condenser 42 and improve the cooling capacity of the refrigerant circulation loop 40 under the first working mode M1, thereby enhancing the cooling effect of the battery 12 and the energy storage converter 13.

[0208] Figure 8 is a schematic diagram of the medium circulation in the thermal management system when the thermal management system is in the second working mode according to an embodiment of the energy storage system of the present disclosure.

[0209] Referring to Figure 8, in some embodiments, the processor 60 is configured to: close the refrigerant circulation loop 40, open the valve 52, and close the heater 22 when the thermal management system 11 is in a second operating mode M2.

[0210] In Figure 8, valve 52 is represented by a thick solid line as being in the open state. When open, valve 52 allows coolant to flow through the entire liquid cooling cycle bypass 50, and the line of the liquid cooling cycle bypass 50 is correspondingly thickened. The lines of the first liquid cooling cycle loop 20 and the second liquid cooling cycle loop 30 are also thickened to indicate coolant flow. The refrigerant cycle loop 40 is closed, shown in Figure 8 without being thickened, at which point compressor 41 can be in a stopped state. Heater 22 is represented by a dashed line as being closed and not providing heating.

[0211] In the second operating mode M2, the first pump 24 drives the coolant to flow through one of the pipes of the third heat exchanger 111, and a portion of the coolant is diverted to the coolant flow path 23 and the liquid cooling circulation bypass 50. The three diverted portions of coolant merge on the other side of the third heat exchanger 111 and flow towards the heater 22. The coolant flows through the heater 22 and enters the first heat exchanger 21, at which point the heater 22 is turned off and does not perform a heating function. The coolant entering the first heat exchanger 21 exchanges heat with the battery 12 to meet the thermal management requirements of the battery 12. The coolant flowing out of the first heat exchanger 21 returns to the first pump 24, thus forming a circulation of coolant in the first liquid cooling circulation loop 20.

[0212] The second pump 31 drives the coolant to another pipe of the third heat exchanger 51, where the coolant can exchange heat with the coolant in the first liquid-cooled circulation loop 20 through the third heat exchanger 51. The coolant enters the second heat exchanger 31 and exchanges heat with the energy storage converter 13 to meet the thermal management requirements of the energy storage converter 13. The coolant flowing out of the second heat exchanger 31 returns to the second pump 32, thus forming a circulation of coolant in the second liquid-cooled circulation loop 30.

[0213] In this embodiment, the liquid cooling circulation bypass 50 is in the conducting state under the second working mode M2. At this time, the cooling or heat absorbed by the coolant flowing through the liquid cooling circulation bypass 50 is provided to the battery 12 when it flows back to the first liquid cooling circulation loop 20, and is transferred to the second liquid cooling circulation loop 30 through heat exchange, which helps to meet the thermal management requirements of the battery 12 and the energy storage converter 13.

[0214] In some embodiments, the processor 60 is configured to switch the thermal management system 11 to the second operating mode M2 ​​in response to an ambient temperature being less than or equal to a second preset temperature T2.

[0215] Ambient temperature refers to the temperature of the environment in which the thermal management system is located, which can be obtained through temperature measuring instruments such as thermometers. The value of the second preset temperature T2 can be set according to the actual situation. For example, the value of the second preset temperature T2 can be set in [-5℃, 10℃], and can be selected as -5℃, -2℃, 0℃, 3℃, 5℃, 7.2℃ or 10℃, etc.

[0216] In this embodiment, by comparing the ambient temperature with a threshold, the thermal management system 11 switches to the second operating mode M2. When the ambient temperature is low, the refrigerant circulation loop and heater can be shut down, and the liquid cooling circulation bypass can absorb the cold energy in the environment, allowing the battery and energy storage converter to be cooled by natural cooling. The first pump 24 in the first liquid cooling circulation loop 20 drives the coolant into the liquid cooling circulation bypass 50 without the need for additional drive components, and the refrigerant circulation system 40 is shut down, thereby saving energy to a greater extent.

[0217] Referring to Figure 8, in some embodiments, the fourth heat exchanger 51 includes a coolant heat dissipation container 511, and the thermal management system 11 further includes a fan 112. The fan 112 is configured to provide air cooling for the coolant heat dissipation container 511. The processor 60 is configured to turn on the fan 112 when the thermal management system 11 is in the second operating mode M2.

[0218] Under the action of the fan 112, the heat exchange between the cooler ambient airflow and the coolant flowing through the coolant heat dissipation container 511 can be accelerated, transferring the cooling capacity of the environment to the liquid cooling circulation bypass 50, and then to the first liquid cooling circulation loop 20 through the coolant. The first liquid cooling circulation loop 20 transfers the cooling capacity to the second liquid cooling circulation loop 30 through the third heat exchanger 111, thereby effectively utilizing the natural cooling capacity of the environment to meet the thermal management requirements of the battery and energy storage converter while reducing system energy consumption.

[0219] Figure 9 is a schematic diagram of the medium circulation in the third working mode of the thermal management system according to an embodiment of the energy storage system of the present disclosure.

[0220] Referring to Figure 9, in some embodiments, the processor 60 is configured to: close the refrigerant circulation loop 40, close the valve 52, and turn on the heater 22 when the thermal management system 11 is in a third operating mode M3.

[0221] In Figure 9, valve 52 is represented by a dashed line as being in the closed state, at which time the corresponding liquid cooling circulation bypass 50 is disconnected. The lines of the first liquid cooling circulation loop 20 and the second liquid cooling circulation loop 30 are bolded to indicate coolant flow. The refrigerant circulation loop 40 is closed, shown in Figure 9 without being bolded, at which point compressor 41 can be shut down. Heater 22 is bolded in Figure 9 to indicate that it is turned on and performing a heating function.

[0222] In the third operating mode M3, the first pump 24 drives the coolant to flow through a pipe of the third heat exchanger 111, and a portion of the coolant is diverted to the coolant flow path 23 before merging again and flowing to the heater 22. The coolant flows through the heater 22 into the first heat exchanger 21, where the heater 22 is activated to raise the temperature of the coolant entering the first heat exchanger 21. The coolant entering the first heat exchanger 21 can exchange heat with the lower-temperature battery 12 to meet its heating requirements. The coolant flowing out of the first heat exchanger 21 returns to the first pump 24, thus forming a coolant circulation loop in the first liquid cooling circuit 20.

[0223] The second pump 31 drives the coolant to another pipe of the third heat exchanger 111, where the coolant can exchange heat with the coolant in the first liquid-cooled circulation loop 20 through the third heat exchanger 111. The coolant enters the second heat exchanger 31 and exchanges heat with the energy storage converter 13 to meet the cooling requirements of the energy storage converter 13. The coolant flowing out of the second heat exchanger 31 returns to the second pump 32, thus forming a circulation of coolant in the second liquid-cooled circulation loop 30.

[0224] When the battery 12 is at a low temperature, its performance, energy consumption, and efficiency will be affected by the low temperature, while the energy storage converter 13 is less affected by low temperatures because it generates more heat during operation. Therefore, when it is necessary to heat the battery 12, heating the energy storage converter 13 does not need to be considered. Moreover, the coolant after heating the battery 12 is at a lower temperature than the energy storage converter 13, and the cooling of the energy storage converter 13 can be achieved through the heat exchange function of the third heat exchanger 111.

[0225] In this embodiment, when the thermal management system 11 is in the third operating mode M3, the processor 60 closes the refrigerant circulation loop 40, closes the valve 52, and turns on the heater 22. The heating effect of the heater 22 can increase the temperature of the coolant entering the first heat exchanger 21, thereby increasing the temperature of the battery 12 and improving its performance, energy consumption, and efficiency. Furthermore, by closing the second valve 52, the coolant does not need to be cooled through the liquid cooling circulation bypass 50, thus avoiding increasing the heating load on the heater 22.

[0226] In some embodiments, the processor 60 is configured to: in response to the temperature of the battery 12 being less than or equal to a third preset temperature T3 and the temperature of the coolant in the upstream flow path of the first liquid cooling circulation loop 20 located in the first heat exchanger 21 being less than a fourth preset temperature T4, switch the thermal management system 11 to the third operating mode M3, wherein the third preset temperature T3 is less than the fourth preset temperature T4.

[0227] The temperature of battery 12 can be obtained by a temperature sensor built into battery 12 or by a temperature sensor located outside battery 12. The temperature of the coolant is the coolant temperature of the first liquid cooling circulation loop 20 located upstream of the first heat exchanger 21, which can be obtained by the first sensor 26 in Figure 9. The values ​​of the third preset temperature T3 and the fourth preset temperature T4 can be set according to actual conditions. The fourth preset temperature T4 is higher than the third preset temperature T3. For example, the value of the third preset temperature T3 is set in [12℃, 20℃], and can be selected as 12℃, 14℃, 15℃, 17℃, 18.5℃ or 20℃, etc. The value of the fourth preset temperature T4 is set in [22℃, 38℃], and can be selected as 22℃, 23℃, 25℃, 28℃, 30℃, 35℃ or 38℃, etc.

[0228] In this embodiment, by comparing the battery temperature and coolant temperature with threshold values, the thermal management system 11 can switch to the third operating mode M3 to meet the heating requirements of the battery 12 when its temperature is low. Furthermore, the coolant temperature is raised by a heater when the coolant itself is low, ensuring smooth battery heating. The coolant used for battery heating, relative to the higher-temperature energy storage converter 13, can meet the cooling requirements of the energy storage converter.

[0229] Figure 10 is a schematic diagram of the medium circulation in the thermal management system under the fourth working mode of the thermal management system according to an embodiment of the energy storage system of the present disclosure.

[0230] Referring to FIG10, in some embodiments, the processor 60 is configured to shut down the refrigerant circulation loop 40, the valve 52, and the heater 22 when the thermal management system 11 is in a fourth operating mode M4.

[0231] In Figure 10, valve 52 is represented by a dashed line as being in the closed state, at which time the corresponding liquid cooling cycle bypass 50 is disconnected. The lines of the first liquid cooling cycle loop 20 and the second liquid cooling cycle loop 30 are thickened to indicate coolant flow. The refrigerant cycle loop 40 is closed, shown in Figure 10 without being thickened, at which point the compressor 41 can be shut down. Heater 22 is represented by a dashed line in Figure 10 as being closed and not providing heating.

[0232] In the fourth operating mode M4, the first pump 24 drives the coolant to flow through a pipe of the third heat exchanger 111, and a portion of the coolant is diverted to the coolant flow path 23 before merging again and flowing to the heater 22. The coolant flows through the heater 22 into the first heat exchanger 21, where the heater 22 is not activated and therefore does not provide heating. The higher-temperature coolant entering the first heat exchanger 21 can exchange heat with the lower-temperature battery 12 to meet its heating requirements. The coolant flowing out of the first heat exchanger 21 returns to the first pump 24, thus forming a coolant circulation loop in the first liquid cooling circuit 20.

[0233] The second pump 31 drives the coolant to another pipe of the third heat exchanger 111, where the coolant can exchange heat with the coolant in the first liquid-cooled circulation loop 20 through the third heat exchanger 111. The coolant enters the second heat exchanger 31 and exchanges heat with the energy storage converter 13 to meet the cooling requirements of the energy storage converter 13. The coolant flowing out of the second heat exchanger 31 returns to the second pump 32, thus forming a circulation of coolant in the second liquid-cooled circulation loop 30.

[0234] In this embodiment, by comparing the battery temperature and coolant temperature with respect to threshold values, the thermal management system 11 can save energy to a greater extent when switching to the fourth operating mode M4. The battery is heated and the energy storage converter is cooled by the circulation and heat exchange of the coolant, utilizing the temperature difference between the battery and the energy storage converter.

[0235] In some embodiments, the processor 60 is configured to: in response to the temperature of the battery 12 being less than or equal to a third preset temperature T3, and the temperature of the coolant in the upstream flow path of the first liquid cooling circulation loop 20 located in the first heat exchanger 21 being greater than or equal to a fourth preset temperature T4 and less than or equal to a fifth preset temperature T5, to switch the thermal management system 11 to the fourth operating mode M4, wherein the fourth preset temperature T4 is greater than the third preset temperature T3, and the fifth preset temperature T5 is greater than the fourth preset temperature T4.

[0236] The temperature of battery 12 can be obtained by a temperature sensor built into battery 12 or by a temperature sensor located outside battery 12. The temperature of the coolant is the coolant temperature of the first liquid cooling circulation loop 20 located upstream of the first heat exchanger 21, which can be obtained by the first sensor 26 in Figure 10. The values ​​of the third preset temperature T3, the fourth preset temperature T4, and the fifth preset temperature T5 can be set according to actual conditions. The fourth preset temperature T4 is greater than the third preset temperature T3, and the fifth preset temperature T5 is greater than the fourth preset temperature T4. For example, the value of the third preset temperature T3 is set in [12℃, 20℃], and can be selected as 12℃, 14℃, 15℃, 17℃, 18.5℃, or 20℃, etc. The value of the fourth preset temperature T4 is set in [22℃, 38℃], and can be selected as 22℃, 23℃, 25℃, 28℃, 30℃, 35℃, or 38℃, etc. The fifth preset temperature T5 is set in [36℃, 44℃], and can be selected as 36℃, 38℃, 40℃, 41℃, 42℃, 43℃ or 44℃, etc.

[0237] In this embodiment, by comparing the temperatures of the battery 12 and the coolant with threshold values, the thermal management system 11 switches to the fourth operating mode M4. This mode satisfies the need for heating of the battery 12 when its temperature is low and the coolant temperature is high, thus improving the performance, energy consumption, and efficiency of the battery 12. Furthermore, it eliminates the need for a heater when the coolant temperature is high, thereby saving energy. Additionally, the coolant recovers heat through heat exchange with the energy storage converter and transfers it to the battery to raise its temperature.

[0238] Figure 11 is a schematic diagram of the medium circulation in the fifth operating mode of the thermal management system according to an embodiment of the energy storage system of the present disclosure. Figure 12 is a schematic diagram of the medium circulation in the sixth operating mode of the thermal management system according to an embodiment of the energy storage system of the present disclosure.

[0239] Referring to Figures 11 and 12, in some embodiments, the processor 60 is configured to: open the refrigerant circulation loop 40, close the valve 52, and close the heater 22 when the thermal management system 11 is in a fifth operating mode M5; and close the refrigerant circulation loop 40, close the valve 52, and close the heater 22 when the thermal management system 11 is in a sixth operating mode M6.

[0240] In Figures 11 and 12, valve 52 is represented by a dashed line as being in the closed state, at which time the corresponding liquid cooling cycle bypass 50 is disconnected. The lines of the first liquid cooling cycle loop 20 and the second liquid cooling cycle loop 30 are thickened to indicate coolant flow. Heater 22 is represented by a dashed line in Figures 11 and 12 as being closed and not providing heating. In Figure 11, the refrigerant cycle loop 40 is open, and its lines are shown in thickened form. In Figure 12, the refrigerant cycle loop 40 is closed, and it is shown without thickening, at which point compressor 41 can be in a stopped state.

[0241] In the fifth operating mode M5, the first pump 24 drives the coolant to flow through a pipe of the third heat exchanger 111, and a portion of the coolant is diverted to the coolant flow path 23 before merging again and flowing to the heater 22. The coolant flows through the heater 22 into the first heat exchanger 21, but the heater 22 is not activated and therefore does not provide heating. The higher-temperature coolant entering the first heat exchanger 21 can exchange heat with the lower-temperature battery 12 to meet its heating requirements. The coolant flowing out of the first heat exchanger 21 returns to the first pump 24, thus forming a coolant circulation loop in the first liquid cooling circuit 20.

[0242] The second pump 31 drives the coolant to another pipe of the third heat exchanger 111, where the coolant can exchange heat with the coolant in the first liquid-cooled circulation loop 20 through the third heat exchanger 111. The coolant enters the second heat exchanger 31 and exchanges heat with the energy storage converter 13 to meet the cooling requirements of the energy storage converter 13. The coolant flowing out of the second heat exchanger 31 returns to the second pump 32, thus forming a circulation of coolant in the second liquid-cooled circulation loop 30.

[0243] In the fifth operating mode M5, the refrigerant circulation loop 40 is in operation. At this time, the compressor 41 is turned on and drives the refrigerant through the condenser 42, the throttling device 43, the liquid receiver 45, and the evaporator 44 before returning to the compressor 41. The refrigerant exchanges heat with the coolant in the coolant flow path 23 in the evaporator 44, thereby transferring the cooling capacity to the first liquid cooling circulation loop 20.

[0244] In the sixth operating mode M6, the first pump 24 drives the coolant to flow through a pipe of the third heat exchanger 111, and a portion of the coolant is diverted to the coolant flow path 23 before merging again and flowing to the heater 22. The coolant flows through the heater 22 into the first heat exchanger 21, where the heater 22 is not activated and therefore does not provide heating. The higher-temperature coolant entering the first heat exchanger 21 can exchange heat with the lower-temperature battery 12 to meet its heating requirements. The coolant flowing out of the first heat exchanger 21 returns to the first pump 24, thus forming a coolant circulation loop in the first liquid cooling circuit 20.

[0245] The second pump 31 drives the coolant to another pipe of the third heat exchanger 111, where the coolant can exchange heat with the coolant in the first liquid-cooled circulation loop 20 through the third heat exchanger 111. The coolant enters the second heat exchanger 31 and exchanges heat with the energy storage converter 13 to meet the cooling requirements of the energy storage converter 13. The coolant flowing out of the second heat exchanger 31 returns to the second pump 32, thus forming a circulation of coolant in the second liquid-cooled circulation loop 30. The refrigerant circulation loop 40 is in the closed state in the sixth operating mode M5, at which time the compressor 41 stops.

[0246] When the coolant temperature is high, it is difficult to effectively cool the battery 12 via the first heat exchanger 21 and the energy storage converter 13 via the second heat exchanger 22. Therefore, in this embodiment, when the thermal management system 11 is in the fifth operating mode M5, the processor 60 opens the refrigerant circulation loop 40, closes the valve 52, and shuts down the heater 22, allowing the coolant to cool down by exchanging heat with the refrigerant in the refrigerant circulation loop 40, thereby more effectively cooling the battery 12 and the energy storage converter 13. Moreover, by closing the valve 52, the coolant does not need to pass through the liquid cooling circulation bypass 50 but instead flows directly through the heat exchange pipe 23 for heat exchange with the refrigerant, which helps to improve the heat exchange efficiency of the evaporator 44. When the coolant temperature is increased, the thermal management system 11 can operate in the sixth operating mode M6. In this mode, the processor 60 closes the refrigerant circulation loop 40, closes the valve 52, and shuts down the heater 22, saving energy consumed by the refrigerant circulation loop 40.

[0247] In some embodiments, the processor 60 is configured to: in response to the temperature of the battery 12 being less than or equal to a third preset temperature T3, and the coolant temperature of the first liquid cooling circulation loop 20 located in the upstream flow path of the first heat exchanger 21 being greater than a fifth preset temperature T5, to switch the thermal management system 11 to the fifth operating mode M5; in response to the thermal management system 11 being in the fifth operating mode M5, and the coolant temperature of the first liquid cooling circulation loop 20 located in the upstream flow path of the first heat exchanger 21 being less than a fourth preset temperature T4, to switch the thermal management system 11 to the sixth operating mode M6; wherein the fifth preset temperature T5 is greater than the fourth preset temperature T4, and the fourth preset temperature T4 is greater than the third preset temperature T3.

[0248] The temperature of battery 12 can be obtained by a temperature sensor built into battery 12 or by a temperature sensor located outside battery 12. The temperature of the coolant is the coolant temperature of the first liquid cooling circulation loop 20 located upstream of the first heat exchanger 21, which can be obtained by the first sensor 26 as shown in Figures 11 and 12. The values ​​of the third preset temperature T3, the fourth preset temperature T4, and the fifth preset temperature T5 can be set according to actual conditions. The fourth preset temperature T4 is greater than the third preset temperature T3, and the fifth preset temperature T5 is greater than the fourth preset temperature T4. For example, the value of the third preset temperature T3 is set in [12℃, 20℃], and can be selected as 12℃, 14℃, 15℃, 17℃, 18.5℃, or 20℃, etc. The value of the fourth preset temperature T4 is set in [22℃, 38℃], and can be selected as 22℃, 23℃, 25℃, 28℃, 30℃, 35℃, or 38℃, etc. The fifth preset temperature T5 is set in [36℃, 44℃], and can be selected as 36℃, 38℃, 40℃, 41℃, 42℃, 43℃ or 44℃, etc.

[0249] In this embodiment, by comparing the battery temperature and coolant temperature with a threshold, when the thermal management system 11 switches to the fifth working mode M5, it can efficiently cool the battery 12 and the energy storage converter 13 by means of the refrigerant circulation loop 40 which exchanges heat with the coolant when the coolant temperature is high. After the coolant temperature is reduced to a certain level, the refrigerant circulation loop 40 is shut off, thereby saving energy consumption.

[0250] Referring to Figure 11, in some embodiments, the refrigerant circulation loop 40 further includes a condenser 42, and the thermal management system 11 further includes a fan 112 configured to air-cool the condenser 42. The processor 60 is configured to turn on the fan 112 when the thermal management system 11 is in the fifth operating mode M5.

[0251] The fan 112 accelerates heat exchange between the ambient airflow and the refrigerant flowing through the condenser 42, thereby improving cooling efficiency. The evaporator 44 transfers cooling capacity to the coolant flow path 23 of the first liquid cooling circulation loop 20 through heat exchange. The first liquid cooling circulation loop 20 then transfers cooling capacity to the second liquid cooling circulation loop 30 through the third heat exchanger 111, thus more effectively meeting the thermal management requirements of the battery and energy storage converter.

[0252] Based on the aforementioned embodiments of the energy storage system 10, this disclosure also provides a corresponding control method. Each step in the control method can be implemented by the processor 60 of the energy storage system 10 executing instructions from the memory.

[0253] Referring to Figures 6-12, this disclosure provides a control method for an energy storage system 10 of any of the foregoing embodiments, including: operating the opening and closing states of the valve 52, the heater 22, and the refrigerant circulation loop 40 according to the operating mode of the thermal management system 11.

[0254] The processor 60 can communicate with components (such as compressor 41) in the valve 52, heater 22 and refrigerant circulation loop 40 via wired or wireless means to operate the opening and closing states of one or more of the valve 52, heater 22 and refrigerant circulation loop 40.

[0255] In this embodiment, the opening and closing states of the valve 52, the heater 22, and the refrigerant circulation loop 40 are operated according to the working mode of the thermal management system 11, so as to meet the thermal management function played by the thermal management system 11 in different working modes.

[0256] Referring to Figure 7, in some embodiments, the steps of operating the opening and closing states of the valve 52, the heater 22, and the refrigerant circulation loop 40 according to the operating mode of the thermal management system 11 include: when the thermal management system 11 is in a first operating mode M1, opening the refrigerant circulation loop 40, closing the valve 52, and closing the heater 22.

[0257] In this embodiment, when the thermal management system 11 is in the first working mode M1, the refrigerant circulation loop 40 is turned on, the valve 52 is turned off, and the heater 22 is turned off. This can make full use of the liquid cooling circulation bypass 50 to assist the liquid cooling circulation loop 30 in improving the cooling effect of the battery 12 and the energy storage converter 13, so as to meet the cooling requirements of the battery 12 and the energy storage converter 13.

[0258] In some embodiments, the control method further includes: in response to the temperature of the energy storage converter 13 being greater than or equal to a first preset temperature T1, switching the thermal management system 11 to the first operating mode M1.

[0259] In this embodiment, by comparing the energy storage converter 13 with a threshold, the thermal management system 11 switches to the first operating mode M1, which can meet the situation where the energy storage converter 13 has a high cooling demand. By utilizing the transfer of cooling capacity from the refrigerant circulation loop 40 to the first liquid cooling circulation loop 20 and the transfer of cooling capacity from the first liquid cooling circulation loop 20 to the second liquid cooling circulation loop 30, the cooling needs of the battery 12 and the energy storage converter 13 are met while saving the energy consumed by the refrigerant circulation system 40, which is beneficial to energy saving.

[0260] Referring to Figure 7, in some embodiments, the refrigerant circulation loop 40 further includes a condenser 42, and the thermal management system 11 further includes a fan 112 configured to air-cool the condenser 42; wherein, the control method further includes: when the thermal management system 11 is in the first operating mode M1, turning on the fan 112.

[0261] In this embodiment, the fan 112 can improve the condensing efficiency of the condenser 42 and improve the cooling capacity of the refrigerant circulation loop 40 under the first working mode M1, thereby enhancing the cooling effect of the battery 12 and the energy storage converter 13.

[0262] Referring to Figure 8, in some embodiments, the steps of operating the opening and closing states of the valve 52, the heater 22, and the refrigerant circulation loop 40 according to the operating mode of the thermal management system 11 include: when the thermal management system 11 is in the second operating mode M2, closing the refrigerant circulation loop 40, opening the valve 52, and closing the heater 22.

[0263] In this embodiment, the liquid cooling circulation bypass 50 is in the conducting state under the second working mode M2. At this time, the cooling or heat absorbed by the coolant flowing through the liquid cooling circulation bypass 50 is provided to the battery 12 when it flows back to the first liquid cooling circulation loop 20, and is transferred to the second liquid cooling circulation loop 30 through heat exchange, which helps to meet the thermal management requirements of the battery 12 and the energy storage converter 13.

[0264] In some embodiments, the control method further includes: in response to an ambient temperature being less than or equal to a second preset temperature T2, switching the thermal management system 11 to the second operating mode M2.

[0265] In this embodiment, by comparing the ambient temperature with a threshold, the thermal management system 11 switches to the second operating mode M2. When the ambient temperature is low, the refrigerant circulation loop and heater can be shut down, and the liquid cooling circulation bypass can absorb the cold energy in the environment, allowing the battery and energy storage converter to be cooled by natural cooling. The first pump 24 in the first liquid cooling circulation loop 20 drives the coolant into the liquid cooling circulation bypass 50 without the need for additional drive components, and the refrigerant circulation system 40 is shut down, thereby saving energy to a greater extent.

[0266] Referring to Figure 8, in some embodiments, the fourth heat exchanger 51 includes a coolant heat dissipation container 511, and the thermal management system 11 further includes a fan 112 configured to air-cool the coolant heat dissipation container 511; wherein, the control method further includes: when the thermal management system 11 is in the second operating mode M2, turning on the fan 112.

[0267] Under the action of the fan 112, the heat exchange between the cooler ambient airflow and the coolant flowing through the coolant heat dissipation container 511 can be accelerated, transferring the cooling capacity of the environment to the liquid cooling circulation bypass 50, and then to the first liquid cooling circulation loop 20 through the coolant. The first liquid cooling circulation loop 20 transfers the cooling capacity to the second liquid cooling circulation loop 30 through the third heat exchanger 111, thereby effectively utilizing the natural cooling capacity of the environment to meet the thermal management requirements of the battery and energy storage converter while reducing system energy consumption.

[0268] Referring to Figure 9, in some embodiments, the steps of operating the opening and closing states of the valve 52, the heater 22, and the refrigerant circulation loop 40 according to the operating mode of the thermal management system 11 include: when the thermal management system 11 is in the third operating mode M3, closing the refrigerant circulation loop 40, closing the valve 52, and opening the heater 22.

[0269] In this embodiment, when the thermal management system 11 is in the third operating mode M3, the refrigerant circulation loop 40 is closed, the valve 52 is closed, and the heater 22 is turned on. The heating effect of the heater 22 can be used to increase the temperature of the coolant entering the first heat exchanger 21, thereby increasing the temperature of the battery 12 and improving the performance, energy consumption, and efficiency of the battery 12. Moreover, by closing the second valve 52, the coolant does not need to be cooled through the liquid cooling circulation bypass 50, thus avoiding increasing the heating load on the heater 22.

[0270] In some embodiments, the control method further includes: in response to the temperature of the battery 12 being less than or equal to a third preset temperature T3 and the temperature of the coolant in the upstream flow path of the first liquid cooling circulation loop 20 located in the first heat exchanger 21 being less than a fourth preset temperature T4, the thermal management system 11 is switched to the third operating mode M3, wherein the third preset temperature T3 is lower than the fourth preset temperature T4.

[0271] In this embodiment, by comparing the battery temperature and coolant temperature with threshold values, the thermal management system 11 can switch to the third operating mode M3 to meet the heating requirements of the battery 12 when its temperature is low. Furthermore, the coolant temperature is raised by a heater when the coolant itself is low, ensuring smooth battery heating. The coolant used for battery heating, relative to the higher-temperature energy storage converter 13, can meet the cooling requirements of the energy storage converter.

[0272] Referring to Figure 10, in some embodiments, the steps of operating the opening and closing states of the valve 52, the heater 22, and the refrigerant circulation loop 40 according to the operating mode of the thermal management system 11 include: when the thermal management system 11 is in the fourth operating mode M4, closing the refrigerant circulation loop 40, closing the valve 52, and closing the heater 22.

[0273] In this embodiment, by comparing the battery temperature and coolant temperature with respect to threshold values, the thermal management system 11 can save energy to a greater extent when switching to the fourth operating mode M4. The battery is heated and the energy storage converter is cooled by the circulation and heat exchange of the coolant, utilizing the temperature difference between the battery and the energy storage converter.

[0274] In some embodiments, the control method further includes: in response to the temperature of the battery 12 being less than or equal to a third preset temperature T3, and the temperature of the coolant in the upstream flow path of the first liquid cooling circulation loop 20 located in the first heat exchanger 21 being greater than or equal to a fourth preset temperature T4 and less than or equal to a fifth preset temperature T5, the thermal management system 11 is switched to the fourth operating mode M4, wherein the fourth preset temperature T4 is greater than the third preset temperature T3, and the fifth preset temperature T5 is greater than the fourth preset temperature T4.

[0275] In this embodiment, by comparing the temperatures of the battery 12 and the coolant with threshold values, the thermal management system 11 switches to the fourth operating mode M4. This mode satisfies the need for heating of the battery 12 when its temperature is low and the coolant temperature is high, thus improving the performance, energy consumption, and efficiency of the battery 12. Furthermore, it eliminates the need for a heater when the coolant temperature is high, thereby saving energy. Additionally, the coolant recovers heat through heat exchange with the energy storage converter and transfers it to the battery to raise its temperature.

[0276] Referring to Figures 11 and 12, in some embodiments, the steps of operating the opening and closing states of the valve 52, the heater 22, and the refrigerant circulation loop 40 according to the operating mode of the thermal management system 11 include: when the thermal management system 11 is in the fifth operating mode M5, opening the refrigerant circulation loop 40, closing the valve 52, and closing the heater 22; and when the thermal management system 11 is in the sixth operating mode M6, closing the refrigerant circulation loop 40, closing the valve 52, and closing the heater 22.

[0277] In this embodiment, when the thermal management system 11 is in the fifth operating mode M5, the refrigerant circulation loop 40 is opened, the valve 52 is closed, and the heater 22 is turned off. This allows the coolant to be cooled by heat exchange with the refrigerant in the refrigerant circulation loop 40, thereby more effectively cooling the battery 12 and the energy storage converter 13. Moreover, by closing the valve 52, the coolant does not need to pass through the liquid cooling circulation bypass 50 but instead flows directly through the heat exchange pipe 23 for heat exchange with the refrigerant, which helps to improve the heat exchange efficiency of the evaporator 44. When the temperature of the coolant is raised, the thermal management system 11 can operate in the sixth operating mode M6. In this mode, the refrigerant circulation loop 40 is closed, the valve 52 is closed, and the heater 22 is turned off, saving the energy consumed by the refrigerant circulation loop 40.

[0278] In some embodiments, the control method further includes: in response to the temperature of the battery 12 being less than or equal to a third preset temperature T3, and the coolant temperature of the first liquid cooling circulation loop 20 located in the upstream flow path of the first heat exchanger 21 being greater than a fifth preset temperature T5, causing the thermal management system 11 to switch to the fifth operating mode M5; in response to the thermal management system 11 being in the fifth operating mode M5, and the coolant temperature of the first liquid cooling circulation loop 20 located in the upstream flow path of the first heat exchanger 21 being less than a fourth preset temperature T4, causing the thermal management system 11 to switch to the sixth operating mode M6; wherein the fifth preset temperature T5 is greater than the fourth preset temperature T4, and the fourth preset temperature T4 is greater than the third preset temperature T3.

[0279] In this embodiment, by comparing the battery temperature and coolant temperature with a threshold, when the thermal management system 11 switches to the fifth working mode M5, it can efficiently cool the battery 12 and the energy storage converter 13 by means of the refrigerant circulation loop 40 which exchanges heat with the coolant when the coolant temperature is high. After the coolant temperature is reduced to a certain level, the refrigerant circulation loop 40 is shut off, thereby saving energy consumption.

[0280] Referring to Figure 11, in some embodiments, the refrigerant circulation loop 40 further includes a condenser 42, and the thermal management system 11 further includes a fan 112 configured to air-cool the condenser 42; wherein, the control method further includes: turning on the fan 112 when the thermal management system 11 is in the fifth operating mode M5.

[0281] The fan 112 accelerates heat exchange between the ambient airflow and the refrigerant flowing through the condenser 42, thereby improving cooling efficiency. The evaporator 44 transfers cooling capacity to the coolant flow path 23 of the first liquid cooling circulation loop 20 through heat exchange. The first liquid cooling circulation loop 20 then transfers cooling capacity to the second liquid cooling circulation loop 30 through the third heat exchanger 111, thus more effectively meeting the thermal management requirements of the battery and energy storage converter.

[0282] This specification describes multiple embodiments in a progressive manner, with each embodiment having a different focus. Similar or identical parts between embodiments can be referred to interchangeably. For the control method embodiments, since their overall structure and content correspond to those in the system embodiments, the description is relatively simple; relevant parts can be referred to in the descriptions of the system embodiments.

[0283] The embodiments of this disclosure have now been described in detail. To avoid obscuring the concept of this disclosure, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0284] While specific embodiments of this disclosure have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this disclosure. The scope of this disclosure is defined by the appended claims.

Claims

1. An energy storage system (10), comprising: Battery (12), used to store and release energy; An energy storage converter (13) is used to connect the power supply source and the battery (12); and Thermal management system (11); The thermal management system (11) includes: The first liquid cooling circulation loop (20) includes a first heat exchanger (21) for exchanging heat with the battery (12); The second liquid-cooled circulation loop (30) includes a second heat exchanger (31) for heat exchange with the energy storage converter (13); and A third heat exchanger (111) is connected to both the first liquid cooling loop (20) and the second liquid cooling loop (30) and is configured to achieve heat exchange between the coolant in the first liquid cooling loop (20) and the coolant in the second liquid cooling loop (30).

2. The energy storage system (10) according to claim 1, wherein, The thermal management system (11) also includes: A heater (22) is disposed in the first liquid cooling circulation loop (20) and is configured to heat the coolant to flow into the first heat exchanger (21).

3. The energy storage system (10) according to claim 1 or 2 further includes: Box (14); The battery (12) is located inside the housing (14), and the energy storage converter (13) is located outside the housing (14).

4. The energy storage system (10) according to any one of claims 1-3, wherein, The thermal management system (11) also includes: A refrigerant circulation loop (40), including an evaporator (44), is configured to achieve refrigerant circulation. The first liquid cooling circulation loop (20) has a coolant flow path (23) passing through the evaporator (44), and the refrigerant in the refrigerant circulation loop (40) and the coolant flow path (23) exchange heat through the evaporator (44).

5. The energy storage system (10) according to claim 4, wherein, The thermal management system (11) also includes: The liquid cooling circulation bypass (50) is connected in parallel with the coolant flow path (23).

6. The energy storage system (10) according to claim 5, wherein, The liquid cooling circulation bypass (50) includes a fourth heat exchanger (51) and a valve (52). The fourth heat exchanger (51) is configured to dissipate heat from the coolant flowing through the liquid cooling circulation bypass (50). The valve (52) is connected in series with the fourth heat exchanger (51) and is configured to operate the on / off state of the liquid cooling circulation bypass (50).

7. The energy storage system (10) according to claim 6, wherein, The refrigerant circulation loop (40) also includes a condenser (42), and the fourth heat exchanger (51) includes a coolant heat dissipation container (511) disposed adjacent to the condenser (42); The thermal management system (11) further includes: A fan (112) is configured to provide air cooling for the condenser (42) and the coolant heat dissipation container (511).

8. The energy storage system (10) according to claim 6 or 7, wherein, The thermal management system (11) also includes a heater (22) disposed in the first liquid cooling circulation loop (20); The energy storage system (10) further includes: The processor (60) is configured to operate the opening and closing states of the valve (52), the heater (22) and the refrigerant circulation loop (40) according to the operating mode of the thermal management system (11).

9. The energy storage system (10) according to claim 8, wherein, The processor (60) is configured to, when the thermal management system (11) is in a first operating mode (M1), open the refrigerant circulation loop (40), close the valve (52), and close the heater (22).

10. The energy storage system (10) according to claim 9, wherein, The processor (60) is configured to switch the thermal management system (11) to the first operating mode (M1) in response to the temperature of the energy storage converter (13) being greater than or equal to a first preset temperature T1.

11. The energy storage system (10) according to claim 9 or 10, wherein, The refrigerant circulation loop (40) also includes a condenser (42), and the thermal management system (11) also includes a fan (112) configured to air-cool the condenser (42); The processor (60) is configured to turn on the fan (112) when the thermal management system (11) is in the first operating mode (M1).

12. The energy storage system (10) according to claim 8, wherein, The processor (60) is configured to close the refrigerant circulation loop (40), open the valve (52), and close the heater (22) when the thermal management system (11) is in a second operating mode (M2).

13. The energy storage system (10) according to claim 12, wherein, The processor (60) is configured to switch the thermal management system (11) to the second operating mode (M2) in response to an ambient temperature less than or equal to a second preset temperature T2.

14. The energy storage system (10) according to claim 12 or 13, wherein, The fourth heat exchanger (51) includes a coolant heat dissipation container (511), and the thermal management system (11) further includes: A fan (112) is configured to air-cool the coolant heat dissipation container (511); The processor (60) is configured to turn on the fan (112) when the thermal management system (11) is in the second operating mode (M2).

15. The energy storage system (10) according to claim 8, wherein, The processor (60) is configured to, when the thermal management system (11) is in the third operating mode (M3), close the refrigerant circulation loop (40), close the valve (52), and turn on the heater (22).

16. The energy storage system (10) according to claim 15, wherein, The processor (60) is configured to switch the thermal management system (11) to the third operating mode (M3) in response to the temperature of the battery (12) being less than or equal to a third preset temperature T3 and the temperature of the coolant in the upstream flow path of the first liquid cooling loop (20) located in the first heat exchanger (21) being less than a fourth preset temperature T4.

17. The energy storage system (10) according to claim 8, wherein, The processor (60) is configured to shut down the refrigerant circulation loop (40), the valve (52), and the heater (22) when the thermal management system (11) is in the fourth operating mode (M4).

18. The energy storage system (10) according to claim 17, wherein, The processor (60) is configured to switch the thermal management system (11) to the fourth operating mode (M4) in response to the temperature of the battery (12) being less than or equal to a third preset temperature T3, and the temperature of the coolant in the upstream flow path of the first liquid cooling loop (20) located in the first heat exchanger (21) being greater than or equal to a fourth preset temperature T4 and less than or equal to a fifth preset temperature T5, wherein the fourth preset temperature T4 is greater than the third preset temperature T3, and the fifth preset temperature T5 is greater than the fourth preset temperature T4.

19. The energy storage system (10) according to claim 8, wherein, The processor (60) is configured to: When the thermal management system (11) is in the fifth operating mode (M5), the refrigerant circulation loop (40) is opened, the valve (52) is closed, and the heater (22) is turned off; and When the thermal management system (11) is in the sixth operating mode (M6), the refrigerant circulation loop (40) is closed, the valve (52) is closed, and the heater (22) is closed.

20. The energy storage system (10) according to claim 19, wherein, The processor (60) is configured to: In response to the temperature of the battery (12) being less than or equal to the third preset temperature T3, and the temperature of the coolant in the upstream flow path of the first liquid cooling circulation loop (20) located in the first heat exchanger (21) being greater than the fifth preset temperature T5, the thermal management system (11) is switched to the fifth working mode (M5). In response to the thermal management system (11) being in the fifth working mode (M5) and the coolant temperature of the first liquid cooling circulation loop (20) located in the upstream flow path of the first heat exchanger (21) being less than the fourth preset temperature T4, the thermal management system (11) is switched to the sixth working mode (M6). Wherein, the fifth preset temperature T5 is greater than the fourth preset temperature T4, and the fourth preset temperature T4 is greater than the third preset temperature T3.

21. The energy storage system (10) according to claim 19 or 20, wherein, The refrigerant circulation loop (40) also includes a condenser (42), and the thermal management system (11) also includes a fan (112) configured to air-cool the condenser (42); The processor (60) is configured to turn on the fan (112) when the thermal management system (11) is in the fifth operating mode (M5).

22. A control method for an energy storage system (10) according to any one of claims 8-21, comprising: The opening and closing states of the valve (52), the heater (22), and the refrigerant circulation loop (40) are operated according to the working mode of the thermal management system (11).

23. The control method according to claim 22, wherein, The steps for operating the valve (52), the heater (22), and the refrigerant circulation loop (40) according to the working mode of the thermal management system (11) include: When the thermal management system (11) is in the first working mode (M1), the refrigerant circulation loop (40) is opened, the valve (52) is closed, and the heater (22) is turned off.

24. The control method according to claim 23, further comprising: In response to the temperature of the energy storage converter (13) being greater than or equal to the first preset temperature T1, the thermal management system (11) is switched to the first operating mode (M1).

25. The control method according to claim 23 or 24, wherein, The refrigerant circulation loop (40) also includes a condenser (42), and the thermal management system (11) also includes a fan (112) configured to air-cool the condenser (42); The control method further includes: When the thermal management system (11) is in the first working mode (M1), the fan (112) is turned on.

26. The control method according to claim 22, wherein, The steps for operating the valve (52), the heater (22), and the refrigerant circulation loop (40) according to the working mode of the thermal management system (11) include: When the thermal management system (11) is in the second working mode (M2), the refrigerant circulation loop (40) is closed, the valve (52) is opened, and the heater (22) is closed.

27. The control method according to claim 26, further comprising: In response to an ambient temperature less than or equal to a second preset temperature T2, the thermal management system (11) switches to the second operating mode (M2).

28. The control method according to claim 26 or 27, wherein, The fourth heat exchanger (51) includes a coolant heat dissipation container (511), and the thermal management system (11) further includes: A fan (112) is configured to air-cool the coolant heat dissipation container (511); The control method further includes: When the thermal management system (11) is in the second working mode (M2), the fan (112) is turned on.

29. The control method according to claim 22, wherein, The steps for operating the valve (52), the heater (22), and the refrigerant circulation loop (40) according to the working mode of the thermal management system (11) include: When the thermal management system (11) is in the third working mode (M3), the refrigerant circulation loop (40) is closed, the valve (52) is closed and the heater (22) is turned on.

30. The control method according to claim 29, further comprising: In response to the temperature of the battery (12) being less than or equal to a third preset temperature T3 and the temperature of the coolant in the upstream flow path of the first liquid cooling loop (20) located in the first heat exchanger (21) being less than a fourth preset temperature T4, the thermal management system (11) is switched to the third operating mode (M3), wherein the third preset temperature T3 is lower than the fourth preset temperature T4.

31. The control method according to claim 22, wherein, The steps for operating the valve (52), the heater (22), and the refrigerant circulation loop (40) according to the working mode of the thermal management system (11) include: When the thermal management system (11) is in the fourth operating mode (M4), the refrigerant circulation loop (40) is closed, the valve (52) is closed, and the heater (22) is closed.

32. The control method according to claim 31, further comprising: In response to the temperature of the battery (12) being less than or equal to the third preset temperature T3, and the temperature of the coolant in the upstream flow path of the first liquid cooling circulation loop (20) located in the first heat exchanger (21) being greater than or equal to the fourth preset temperature T4 and less than or equal to the fifth preset temperature T5, the thermal management system (11) is switched to the fourth working mode (M4), wherein the fourth preset temperature T4 is greater than the third preset temperature T3, and the fifth preset temperature T5 is greater than the fourth preset temperature T4.

33. The control method according to claim 22, wherein, The steps for operating the valve (52), the heater (22), and the refrigerant circulation loop (40) according to the working mode of the thermal management system (11) include: When the thermal management system (11) is in the fifth operating mode (M5), the refrigerant circulation loop (40) is opened, the valve (52) is closed, and the heater (22) is turned off; and When the thermal management system (11) is in the sixth operating mode (M6), the refrigerant circulation loop (40) is closed, the valve (52) is closed, and the heater (22) is closed.

34. The control method according to claim 33, further comprising: In response to the temperature of the battery (12) being less than or equal to the third preset temperature T3, and the temperature of the coolant in the upstream flow path of the first liquid cooling circulation loop (20) located in the first heat exchanger (21) being greater than the fifth preset temperature T5, the thermal management system (11) is switched to the fifth working mode (M5). In response to the thermal management system (11) being in the fifth working mode (M5) and the coolant temperature of the first liquid cooling circulation loop (20) located in the upstream flow path of the first heat exchanger (21) being less than the fourth preset temperature T4, the thermal management system (11) is switched to the sixth working mode (M6). Wherein, the fifth preset temperature T5 is greater than the fourth preset temperature T4, and the fourth preset temperature T4 is greater than the third preset temperature T3.

35. The control method according to claim 33 or 34, wherein, The refrigerant circulation loop (40) also includes a condenser (42), and the thermal management system (11) also includes a fan (112) configured to air-cool the condenser (42); The control method further includes: When the thermal management system (11) is in the fifth working mode (M5), the fan (112) is turned on.

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