Energy storage system and control method therefor

Abstract

An energy storage system (10) and a control method therefor. The energy storage system (10) comprises: a battery (12) for storing and releasing energy; an energy storage converter (13) used for being connected to a power supply source and the battery (12); and a thermal management system (11), the thermal management system (11) comprising: a first heat exchanger (21) used for performing heat exchange with the battery (12); a second heat exchanger (22) used for performing heat exchange with the energy storage converter (13); and a liquid cooling circulation loop (30) having a first coolant flow path (31) and a second coolant flow path (32) which are in communication in parallel, the first heat exchanger (21) being arranged in the first coolant flow path (31), and the second heat exchanger (22) being arranged in the second coolant flow path (32).

Description

Energy storage systems and their control methods

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411025173.9, filed on July 29, 2024, entitled “Energy Storage System and Control Method Thereof,” the entire contents of which are incorporated herein by reference. 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:

[0006] Batteries are used to store and release energy;

[0007] An energy storage converter for connecting the power supply source and the battery; and

[0008] Thermal management system;

[0009] The thermal management system includes:

[0010] A first heat exchanger is used for heat exchange with the battery;

[0011] A second heat exchanger is used for heat exchange with the energy storage converter; and

[0012] The liquid cooling circulation loop has a first coolant flow path and a second coolant flow path connected in parallel.

[0013] The first heat exchanger is located in the first coolant flow path, and the second heat exchanger is located in the second coolant flow path.

[0014] In this embodiment, by placing the first heat exchanger that exchanges heat with the battery and the second heat exchanger that exchanges heat with the energy storage converter in parallel within the first and second coolant flow paths of the liquid cooling loop, the battery and the energy storage converter can be thermally managed through the same liquid cooling loop. This eliminates the need for two or more liquid cooling systems, effectively reducing the size, weight, and related costs of the thermal management system, and thus improving energy efficiency. Furthermore, the parallel connection of the first and second coolant flow paths allows for independent configuration and control based on the thermal management requirements of the battery and the energy storage converter, meeting more flexible thermal management needs.

[0015] In some embodiments, the liquid cooling circulation loop further includes:

[0016] A heater, disposed in the first coolant flow path, is configured to heat the coolant flowing into the first heat exchanger.

[0017] In this embodiment, by placing the heater in the first coolant flow path, the coolant flowing through the first coolant flow path can be heated to increase the temperature of the coolant, thereby raising the battery temperature through the first heat exchanger when the battery temperature is low.

[0018] In some embodiments, the liquid cooling circulation loop further includes:

[0019] A first valve is disposed in the second coolant flow path and is configured to operate on / off the second coolant flow path.

[0020] In this embodiment, by setting a first valve in the second coolant flow path, the first valve is used to realize the opening and closing of the second coolant flow path, thereby increasing the controllability of the liquid cooling circulation loop by allowing the coolant in the liquid cooling circulation loop to flow through the second heat exchanger or not flow through the second coolant flow path as needed.

[0021] In some embodiments, the diameter of the pipe for circulating coolant in the first heat exchanger is configured to be the same as or different from the diameter of the pipe for circulating coolant in the second heat exchanger.

[0022] Using a first and second heat exchanger with the same pipe diameter simplifies assembly and eliminates the need for some variable-diameter components. Conversely, using a first and second heat exchanger with different pipe diameters allows for the distribution of coolant flow through the first and second coolant paths, effectively meeting the thermal management requirements of the battery and energy storage converter.

[0023] In some embodiments, the thermal management system further includes:

[0024] The refrigerant circulation loop includes an evaporator.

[0025] The refrigerant circulation loop is configured to circulate the refrigerant and exchange heat with the liquid cooling circulation loop through an evaporator. The liquid cooling circulation loop has a heat exchange pipeline that passes through the evaporator and is connected to the first and second cooling liquid flow paths in parallel.

[0026] In this embodiment, heat exchange between the refrigerant circulation loop and the liquid cooling circulation loop provides cooling or heating to the coolant in the refrigerant circulation loop, which improves the thermal management efficiency of the refrigerant 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 liquid cooling circulation loop via the evaporator's heat exchange pipes, effectively reducing the temperature of the coolant flowing in the liquid cooling circulation loop and meeting the cooling requirements of the thermal management system.

[0027] In some embodiments, the energy storage thermal management system further includes:

[0028] A liquid cooling circulation bypass is connected in parallel with the heat exchange pipeline;

[0029] The liquid cooling circulation bypass includes a third heat exchanger and a second valve. The third heat exchanger is configured to dissipate heat from the coolant flowing through the liquid cooling circulation bypass. The second valve is connected in series with the third heat exchanger and is configured to operate the on / off state of the liquid cooling circulation bypass.

[0030] In this embodiment, by setting a second valve in the liquid cooling circulation bypass, the liquid cooling circulation bypass can be opened and closed using the second valve. This allows the coolant in the liquid cooling circulation loop to be partially diverted to the liquid cooling circulation bypass for heat exchange as needed, or not diverted to the liquid cooling circulation bypass for heat exchange, thereby increasing the controllability of the coolant circulation system.

[0031] In some embodiments, the refrigerant circulation loop further includes a condenser, and the third heat exchanger includes a coolant heat dissipation container disposed adjacent to the condenser;

[0032] The thermal management system further includes:

[0033] A fan is configured to provide air cooling for the condenser and the coolant heat dissipation container.

[0034] In this embodiment, by placing the condenser and the coolant heat dissipation container adjacent to each other, and utilizing the airflow driven by the fan, the condenser and the coolant heat dissipation container are simultaneously cooled by air, which helps to improve air cooling efficiency and reduce energy consumption.

[0035] In some embodiments, the coolant heat dissipation container is located upstream of the condenser along the airflow direction of the fan.

[0036] In this embodiment, by positioning the coolant heat dissipation container upstream of the condenser along the airflow direction of the fan, it is beneficial to balance the air-cooling effect of both the coolant heat dissipation container and the condenser.

[0037] In some embodiments, the thermal management system further includes:

[0038] A liquid cooling circulation bypass is connected to the liquid cooling circulation loop;

[0039] The liquid cooling circulation bypass includes a third heat exchanger and a second valve. The third heat exchanger is configured to dissipate heat from the coolant flowing through the liquid cooling circulation bypass. The second valve is connected in series with the third heat exchanger and is configured to operate the on / off state of the liquid cooling circulation bypass.

[0040] In this embodiment, by setting a second valve in the liquid cooling circulation bypass, the liquid cooling circulation bypass can be opened and closed using the second valve. This allows the coolant in the liquid cooling circulation loop to be partially diverted to the liquid cooling circulation bypass for heat exchange as needed, or not diverted to the liquid cooling circulation bypass for heat exchange, thereby increasing the controllability of the coolant circulation system.

[0041] In some embodiments, the thermal management system further includes: a heater disposed in the first coolant flow path and a first valve disposed in the second coolant flow path;

[0042] The energy storage system further includes:

[0043] The processor is configured to, when the energy storage thermal management system is in a first operating mode, open the first valve, open the second valve, and close the heater.

[0044] In this embodiment, through the signal connection between the processor and the first valve, the second valve, and the heater, the processor can operate the opening and closing states of the first valve, the second valve, and the heater according to the operating mode of the energy storage thermal management system. When the energy storage thermal management system is in its first operating mode, by having the processor open the first valve, open the second valve, and close the heater, the cooling effect of the liquid-cooled circulation bypass auxiliary liquid-cooled circulation loop can be fully utilized to improve the cooling effect of the battery and the energy storage converter, thereby meeting the cooling requirements of the battery and the energy storage converter.

[0045] In some embodiments, the third 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; the processor is configured to turn on the fan when the thermal management system is in the first operating mode.

[0046] In this embodiment, the fan can improve the air cooling efficiency of the coolant heat dissipation container in the first working mode and enhance the effect of the liquid cooling circulation bypass on improving the cooling effect of the battery and energy storage converter in the liquid cooling circulation loop.

[0047] In some embodiments, the processor is configured to switch the thermal management system to the first operating mode in response to an ambient temperature being lower than or equal to a first preset temperature.

[0048] In this embodiment, by comparing the ambient temperature with a threshold, the thermal management system switches to the first working mode, which can meet the situation where the battery and energy storage converter have low cooling requirements, saving the energy consumed by the refrigerant circulation system and thus saving energy.

[0049] In some embodiments, the thermal management system further includes: a heater disposed in the first coolant flow path and a first valve disposed in the second coolant flow path;

[0050] The energy storage system further includes:

[0051] The processor is configured to close the first valve, close the second valve, and turn on the heater when the thermal management system is in a second operating mode, and to close the first valve, close the second valve, and turn off the heater when the thermal management system is in the third operating mode.

[0052] In this embodiment, when the thermal management system is in the second operating mode, the processor closes the first valve and the second valve, and turns on the heater. The heating effect of the heater allows the higher-temperature coolant to raise the battery temperature, improving battery performance, energy consumption, and efficiency. Furthermore, closing the first valve directs the coolant to the first heat exchanger, improving the battery's heat exchange efficiency. Closing the second valve eliminates the need for the coolant to bypass the liquid cooling circulation path, thus reducing the heating load on the heater.

[0053] For coolants at higher temperatures, when the thermal management system is in the third operating mode, the processor closes the first valve, the second valve, and the heater. This effectively increases the battery temperature without the need for the heater to heat the battery, thereby improving battery performance, energy consumption, and efficiency.

[0054] In some embodiments, the processor is configured to switch the thermal management system to the second operating mode in response to the battery temperature being lower than or equal to a second preset temperature and the coolant temperature being lower than or equal to a third preset temperature, and to switch the thermal management system to the third operating mode in response to the battery temperature being lower than or equal to the second preset temperature and the coolant temperature being higher than the third preset temperature, wherein the coolant temperature is the coolant temperature of the liquid cooling circulation loop upstream of the parallel-connected first and second coolant flow paths, and the third preset temperature is higher than the second preset temperature.

[0055] In this embodiment, by comparing the battery temperature and coolant temperature with threshold values, the thermal management system can switch to the second operating mode to meet the heating requirement when the battery temperature is low, and raise the temperature of the coolant by a heater when the coolant temperature is low, so that the battery heating can proceed smoothly. Conversely, by comparing the battery temperature and coolant temperature with threshold values, the thermal management system can switch to the third operating mode to meet the heating requirement when the battery temperature is low, and eliminate the need for heater heating when the coolant temperature is high, thereby saving energy.

[0056] In some embodiments, the thermal management system further includes: a heater disposed in the first coolant flow path and a first valve disposed in the second coolant flow path;

[0057] The energy storage system further includes:

[0058] The processor is configured to open the first valve, close the second valve, and turn on the heater when the thermal management system is in a fourth operating mode, and to open the first valve, close the second valve, and turn off the heater when the thermal management system is in a fifth operating mode.

[0059] In this embodiment, when the thermal management system is in the fourth operating mode, the processor opens the first valve, closes the second valve, and turns on the heater. The heater's heating effect raises the temperature of the coolant entering the first coolant flow path, thereby increasing the battery temperature and improving battery performance, energy consumption, and efficiency. Meanwhile, the coolant entering the second coolant flow path cools the energy storage converter. Furthermore, by closing the second valve, the coolant does not need to bypass the liquid cooling circulation to dissipate heat, thus avoiding increasing the heating load on the heater.

[0060] When the thermal management system is in the fifth operating mode, the processor opens the first valve, closes the second valve, and shuts down the heater. The coolant plays different roles in the first coolant flow path and the second coolant flow path. The coolant entering the first coolant flow path heats the battery, improving its performance, energy consumption, and efficiency. The coolant entering the second coolant flow path cools the energy storage converter, and the heater is not turned on to save energy consumption.

[0061] In some embodiments, the processor is configured to switch the thermal management system to the fourth operating mode in response to the temperature of the energy storage converter being higher than or equal to a fourth preset temperature and the temperature of the coolant being lower than the fifth preset temperature, and to switch the thermal management system to the fifth operating mode in response to the temperature of the energy storage converter being higher than or equal to the fourth preset temperature and the temperature of the coolant being lower than or equal to the fifth preset temperature and higher than or equal to a sixth preset temperature, wherein the temperature of the coolant is the coolant temperature of the flow path of the liquid cooling circulation loop upstream of the parallel-connected first and second coolant flow paths, the fifth preset temperature is lower than the sixth preset temperature, and the sixth preset temperature is lower than the fourth preset temperature.

[0062] In this embodiment, by comparing the temperatures of the energy storage converter and the coolant with threshold values, the thermal management system, when switching to the fourth operating mode, can meet the cooling needs of the energy storage converter when it is hot, and raise the temperature of the coolant by a heater when the coolant temperature is low, allowing for smooth battery heating. Conversely, by comparing the temperatures of the energy storage converter and the coolant with threshold values, the thermal management system, when switching to the fifth operating mode, can meet the cooling needs of the energy storage converter when it is hot, and eliminate the need for a heater when the coolant temperature is high, thus saving energy. Furthermore, the heat released from the energy storage converter into the coolant can be recovered as waste heat and provided to the battery to raise its temperature, saving energy used for heating.

[0063] In some embodiments, the thermal management system further includes:

[0064] The refrigerant circulation loop is configured to circulate the refrigerant and exchange heat with the liquid cooling circulation loop;

[0065] The refrigerant circulation loop includes an evaporator; the liquid cooling circulation loop includes a heat exchange pipeline that passes through the evaporator and is connected in parallel with the first and second coolant flow paths, and the liquid cooling circulation bypass is connected in parallel with the heat exchange pipeline; the processor is configured to operate the opening and closing state of the refrigerant circulation loop according to the operating mode of the thermal management system.

[0066] In this embodiment, a refrigerant circulation loop is set up to achieve heat exchange with the liquid cooling circulation loop, and the processor controls the opening and closing state of the refrigerant circulation loop to meet the different cooling requirements of the thermal management system.

[0067] In some embodiments, the processor is configured to shut down the refrigeration cycle of the refrigerant circulation loop when the thermal management system is in any of the first, second, third, fourth, and fifth operating modes.

[0068] In a thermal management system, if a battery has either a heating requirement or a relatively low cooling requirement, the thermal management system can save energy by shutting down the refrigeration cycle of the refrigerant circulation loop while meeting the battery's cooling or heating requirements.

[0069] In some embodiments, the processor is configured to, when the thermal management system is in a sixth operating mode, open the first valve, close the second valve and shut down the heater, and activate the refrigerant circulation loop for refrigeration.

[0070] In this embodiment, when the thermal management system is in its sixth operating mode, the processor opens the first valve, closes the second valve, and shuts down the heater. This activates the refrigerant circulation loop, allowing the coolant to cool down through heat exchange with the refrigerant in the circulation loop, thus more effectively cooling the battery and energy storage converter. Furthermore, closing the second valve allows the coolant to bypass the liquid cooling circulation loop and instead flow directly through the heat exchange pipe with the refrigerant, improving the evaporator's heat exchange efficiency.

[0071] In some embodiments, the processor is configured to switch the thermal management system to the sixth operating mode in response to the temperature of the coolant being higher than or equal to a seventh preset temperature, wherein the temperature of the coolant is the coolant temperature of the flow path of the liquid cooling circulation loop upstream of the first and second parallel-connected coolant flow paths.

[0072] In this embodiment, by comparing the temperature of the coolant with a threshold, when the thermal management system switches to the sixth 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 itself is at a high temperature.

[0073] In one aspect of this disclosure, a control method for the aforementioned energy storage system is provided, wherein the thermal management system further includes: a heater disposed in the first coolant flow path and a first valve disposed in the second coolant flow path, and the energy storage system further includes a processor; wherein the control method includes:

[0074] The opening and closing states of the first valve, the second valve, and the heater are operated according to the working mode of the thermal management system.

[0075] In this embodiment, the opening and closing states of the first valve, the second valve, and the heater 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.

[0076] In some embodiments, the step of operating the opening and closing states of the first valve, the second valve, and the heater according to the operating mode of the thermal management system includes:

[0077] When the thermal management system is in a first operating mode, the first valve is opened, the second valve is opened, and the heater is turned off.

[0078] In this embodiment, when the thermal management system is in the first working mode, the processor opens the first valve, the second valve, and the heater, which can make full use of the liquid cooling circulation bypass to assist the liquid cooling circulation loop to improve the cooling effect of the battery and the energy storage converter, so as to meet the cooling requirements of the battery and the energy storage converter.

[0079] In some embodiments, the third 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;

[0080] The control method further includes:

[0081] When the thermal management system is in the first operating mode, the fan is turned on.

[0082] In this embodiment, the fan can improve the air cooling efficiency of the coolant heat dissipation container in the first working mode and enhance the effect of the liquid cooling circulation bypass on improving the cooling effect of the battery and energy storage converter in the liquid cooling circulation loop.

[0083] In some embodiments, the control method further includes:

[0084] In response to an ambient temperature lower than or equal to a first preset temperature, the thermal management system switches to the first operating mode.

[0085] In this embodiment, by comparing the ambient temperature with a threshold, the thermal management system switches to the first working mode, which can meet the situation where the battery and energy storage converter have low cooling requirements, saving the energy consumed by the refrigerant circulation system and thus saving energy.

[0086] In some embodiments, the step of operating the opening and closing states of the first valve, the second valve, and the heater according to the operating mode of the thermal management system includes:

[0087] When the thermal management system is in the second operating mode, the first valve is closed, the second valve is closed, and the heater is turned on.

[0088] When the thermal management system is in the third operating mode, the first valve is closed, the second valve is closed, and the heater is turned off.

[0089] In this embodiment, when the thermal management system is in the second operating mode, the first valve and the second valve are closed, and the heater is turned on. The heating effect of the heater allows the higher-temperature coolant to raise the battery temperature, improving battery performance, energy consumption, and efficiency. Furthermore, closing the first valve directs the coolant to the first heat exchanger, which improves the efficiency of battery heat exchange. Closing the second valve eliminates the need for the coolant to bypass the liquid cooling circulation path, thus reducing the heating load on the heater.

[0090] For coolants at higher temperatures, when the thermal management system is in the third operating mode, the first valve is closed, the second valve is closed, and the heater is turned off. This effectively increases the battery temperature without the need for the heater to heat the battery, thereby improving battery performance, energy consumption, and efficiency.

[0091] In some embodiments, the control method further includes:

[0092] In response to the battery temperature being lower than or equal to a second preset temperature and the coolant temperature being lower than or equal to a third preset temperature, the thermal management system switches to the second operating mode;

[0093] In response to the battery temperature being lower than or equal to the second preset temperature and the coolant temperature being higher than the third preset temperature, the thermal management system switches to the third operating mode;

[0094] The temperature of the coolant is the coolant temperature of the upstream flow path of the liquid cooling circulation loop in the first and second parallel coolant flow paths, and the third preset temperature is higher than the second preset temperature.

[0095] In this embodiment, by comparing the battery temperature and coolant temperature with threshold values, the thermal management system can switch to the second operating mode to meet the heating requirement when the battery temperature is low, and raise the temperature of the coolant by a heater when the coolant temperature is low, so that the battery heating can proceed smoothly. Conversely, by comparing the battery temperature and coolant temperature with threshold values, the thermal management system can switch to the third operating mode to meet the heating requirement when the battery temperature is low, and eliminate the need for heater heating when the coolant temperature is high, thereby saving energy.

[0096] In some embodiments, the step of operating the opening and closing states of the first valve, the second valve, and the heater according to the operating mode of the thermal management system includes:

[0097] When the thermal management system is in the fourth operating mode, the first valve is opened, the second valve is closed, and the heater is turned on.

[0098] When the thermal management system is in the fifth operating mode, the first valve is opened, the second valve is closed, and the heater is turned off.

[0099] In this embodiment, when the thermal management system is in the fourth operating mode, the first valve is opened, the second valve is closed, and the heater is turned on. The heating effect of the heater raises the temperature of the coolant entering the first coolant flow path, thereby increasing the battery temperature and improving battery performance, energy consumption, and efficiency. The coolant entering the first coolant flow path then cools the energy storage converter. Furthermore, by closing the second valve, the coolant does not need to bypass the liquid cooling circulation to dissipate heat, thus avoiding increasing the heating load on the heater.

[0100] In some embodiments, the control method further includes:

[0101] In response to the temperature of the energy storage converter being higher than or equal to the fourth preset temperature and the temperature of the coolant being lower than the fifth preset temperature, the thermal management system switches to the fourth operating mode.

[0102] In response to the temperature of the energy storage converter being higher than or equal to the fourth preset temperature, and the temperature of the coolant being lower than or equal to the fifth preset temperature but higher than or equal to the sixth preset temperature, the thermal management system switches to the fifth operating mode.

[0103] The temperature of the coolant is the coolant temperature of the flow path upstream of the first and second parallel coolant flow paths in the liquid cooling circulation loop. The fifth preset temperature is lower than the sixth preset temperature, and the sixth preset temperature is lower than the fourth preset temperature.

[0104] In this embodiment, by comparing the temperatures of the energy storage converter and the coolant with threshold values, the thermal management system, when switching to the fourth operating mode, can meet the cooling needs of the energy storage converter when it is hot, and raise the temperature of the coolant by a heater when the coolant temperature is low, allowing for smooth battery heating. Conversely, by comparing the temperatures of the energy storage converter and the coolant with threshold values, the thermal management system, when switching to the fifth operating mode, can meet the cooling needs of the energy storage converter when it is hot, and eliminate the need for a heater when the coolant temperature is high, thus saving energy. Furthermore, the heat released from the energy storage converter into the coolant can be recovered as waste heat and provided to the battery to raise its temperature, saving energy used for heating.

[0105] In some embodiments, the thermal management system further includes: a refrigerant circulation loop configured to circulate refrigerant and exchange heat with the liquid cooling circulation loop; the refrigerant circulation loop having an evaporator; the liquid cooling circulation loop having a heat exchange pipeline that passes through the evaporator and is connected in parallel with the first and second cooling liquid flow paths, and the liquid cooling circulation bypass is connected in parallel with the heat exchange pipeline;

[0106] The control method further includes:

[0107] The opening and closing status of the refrigerant circulation loop is operated according to the working mode of the thermal management system.

[0108] In this embodiment, a refrigerant circulation loop is set up to achieve heat exchange with the liquid cooling circulation loop, and to control the opening and closing state of the refrigerant circulation loop in order to meet the different cooling requirements of the thermal management system.

[0109] In some embodiments, the step of operating the opening and closing state of the refrigerant circulation loop according to the operating mode of the thermal management system includes:

[0110] When the thermal management system is in any of the first, second, third, fourth, and fifth operating modes, the refrigeration cycle of the refrigerant circulation loop is shut off.

[0111] In a thermal management system, if a battery has either a heating requirement or a relatively low cooling requirement, the thermal management system can save energy by shutting down the refrigeration cycle of the refrigerant circulation loop while meeting the battery's cooling or heating requirements.

[0112] In some embodiments, the step of controlling the opening and closing states of the first valve, the second valve, and the heater according to the operating mode of the thermal management system includes:

[0113] When the thermal management system is in the sixth operating mode, the first valve is opened, the second valve is closed, and the heater is turned off;

[0114] The steps for determining the opening and closing status of the refrigerant circulation loop based on the operating mode of the thermal management system include:

[0115] When the thermal management system is in the sixth operating mode, the refrigerant circulation loop starts the refrigeration cycle.

[0116] In this embodiment, when the thermal management system is in its sixth operating mode, the first valve is opened, the second valve is closed, and the heater is turned off. The refrigerant circulation loop is activated for refrigeration, allowing the coolant to cool down through heat exchange with the refrigerant in the circulation loop. This more effectively cools the battery and the energy storage converter. Furthermore, by closing the second valve, the coolant bypasses the liquid cooling circulation and flows directly through the heat exchange pipe with the refrigerant, improving the heat exchange efficiency of the evaporator.

[0117] In some embodiments, the control method further includes:

[0118] In response to the coolant temperature being higher than or equal to a seventh preset temperature, the thermal management system switches to the sixth operating mode, where the coolant temperature is the coolant temperature of the upstream flow path of the liquid cooling circulation loop in the parallel-connected first and second coolant flow paths.

[0119] In this embodiment, by comparing the temperature of the coolant with a threshold, when the thermal management system switches to the sixth 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 itself is at a high temperature. Attached Figure Description

[0120] 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.

[0121] This disclosure will become clearer with reference to the accompanying drawings and the following detailed description, wherein:

[0122] Figure 1 is a schematic diagram of the structure of some embodiments of the energy storage system according to the present disclosure;

[0123] Figure 2 is a schematic diagram of the structure of the thermal management system according to an embodiment of the energy storage system of this disclosure;

[0124] Figure 3 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;

[0125] Figure 4 is a schematic diagram of control signal connections according to an embodiment of the thermal management system of the energy storage system of the present disclosure;

[0126] 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;

[0127] Figure 6 is a schematic diagram of the structure of the thermal management system according to some embodiments of the energy storage system of the present disclosure;

[0128] 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;

[0129] 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;

[0130] 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;

[0131] 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;

[0132] 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;

[0133] 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.

[0134] 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.

[0135] The reference numerals in the attached diagrams represent: 10-Energy storage system; 11-Thermal management system; 12-Battery; 13-Power Conversion System (PCS); 21-First heat exchanger; 22-Second heat exchanger; 30-Liquid cooling circulation loop; 31-First coolant flow path; 32-Second coolant flow path; 33-Heater; 34-First valve; 35-Heat exchange piping; 36-Pump; 37-Expansion tank; 38-First sensor; 39-Second sensor; 40-Refrigerant circulation loop; 41-Compressor; 42-Condenser; 43-Throttling device; 44-Evaporator; 45-Fan; 46-Liquid receiver; 47-First pressure sensor; 48-Second pressure sensor; 50-Liquid cooling circulation bypass; 51-Third heat exchanger; 511-Coolant heat dissipation container; 52-Second 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

[0136] 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.

[0137] 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.

[0138] 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.

[0139] 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.

[0140] 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.

[0141] 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.

[0142] In this disclosure, "multiple" means two or more (including two).

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] 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).

[0155] 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 0.2O2 (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.

[0156] In some embodiments, the negative electrode sheet may include a negative current collector substrate.

[0157] 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.).

[0158] In some embodiments, the negative electrode sheet may include a negative current collector substrate and a negative active material layer disposed on at least one surface of the negative current collector substrate.

[0159] 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.

[0160] 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.

[0161] 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.

[0162] 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.

[0163] 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.

[0164] 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.

[0165] 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.

[0166] As an example, liquid electrolytes include electrolyte salts and solvents.

[0167] 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.

[0168] 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.

[0169] As an example, gel electrolytes include a polymer-based backbone network combined with an ionic liquid—a lithium salt.

[0170] As an example, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0171] 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.

[0172] 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 phosphorus sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0173] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0174] 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.

[0175] 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.

[0176] 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.

[0177] 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).

[0178] 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.

[0179] 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.

[0180] 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.

[0181] 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.

[0182] 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.

[0183] In view of this, the present disclosure provides an energy storage system and its control method, which is beneficial to meet the different thermal management requirements of batteries and energy storage converters in the energy storage system.

[0184] 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 heat exchanger for exchanging heat with the battery; a second heat exchanger for exchanging heat with the energy storage converter; and a liquid-cooled circulation loop having a first coolant flow path and a second coolant flow path connected in parallel; wherein the first heat exchanger is disposed in the first coolant flow path, and the second heat exchanger is disposed in the second coolant flow path.

[0185] 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 set in a first coolant flow path and a second coolant flow path connected in parallel in the liquid cooling circulation loop. This parallel connection allows the first coolant flow path and the second coolant flow path to be configured and controlled independently according to the thermal management requirements of the battery and the energy storage converter, thus meeting more flexible thermal management requirements.

[0186] 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 the thermal management system in an embodiment of the energy storage system according to the present disclosure.

[0187] Referring to Figures 1 and 2, 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 heat exchanger 21, a second heat exchanger 22, and a liquid-cooled circulation loop 30. The first heat exchanger 21 is used to exchange heat with the battery 12. The second heat exchanger 22 is used to exchange heat with the energy storage converter 13. The liquid-cooled circulation loop 30 has a first coolant flow path 31 and a second coolant flow path 32 connected in parallel. The first heat exchanger 21 is located in the first coolant flow path 31, and the second heat exchanger 22 is located in the second coolant flow path 32.

[0188] 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 13 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 13 acts as an inverter to convert the DC power from the DC side into AC power and supply it to the grid.

[0189] 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.

[0190] The coolant flowing in the liquid-cooled circulation loop 30 can be water, aqueous coolant, or anhydrous coolant. A first heat exchanger 21 is disposed in the first coolant flow path 31, and the coolant flowing in the first coolant flow path 31 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 through, but not limited to, thermal conduction; for example, the first heat exchanger 21 may include a cooling plate in contact with the battery 12. A second heat exchanger 22 is disposed in the second coolant flow path 32, and the coolant flowing in the second coolant flow path 32 can exchange heat with the energy storage converter 13 in the second heat exchanger 22. The second heat exchanger 22 can transfer heat to the energy storage converter 13 through, but not limited to, thermal conduction; for example, the second heat exchanger 22 may include a cooling plate in contact with the energy storage converter 13.

[0191] 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.

[0192] In this embodiment, by respectively arranging the first heat exchanger 21 that exchanges heat with the battery 12 and the second heat exchanger 22 that exchanges heat with the energy storage converter 13 in parallel connection of the first coolant flow path 31 and the second coolant flow path 32 in the liquid cooling circulation loop 30, the battery 12 and the energy storage converter 13 can be thermally managed through the same liquid cooling loop, eliminating the need for two or more liquid cooling systems, effectively reducing the size, weight, and related costs of the thermal management system, and improving energy efficiency. Moreover, the parallel connection of the first coolant flow path 31 and the second coolant flow path 32 allows for independent configuration and control according to the thermal management requirements of the battery 12 and the energy storage converter 13, meeting more flexible thermal management needs.

[0193] Referring to FIG2, in some embodiments, the liquid cooling circulation loop 30 further includes a heater 33. The heater 33 is disposed in the first coolant flow path 31 and is configured to heat the coolant flowing into the first heat exchanger 21.

[0194] Heater 33 may be an electric heater, a steam heater, or any other available heater. For example, heater 33 may be a safe and efficient positive temperature coefficient (PTC) heater.

[0195] In this embodiment, by placing the heater 33 in the first coolant flow path 31, the coolant flowing through the first coolant flow path 31 can be heated to increase the temperature of the coolant, thereby increasing the temperature of the battery 12 through the first heat exchanger 21 when the battery 12 temperature is low.

[0196] Referring to Figure 2, in some embodiments, the liquid cooling circulation loop 30 further includes a first valve 34. The first valve 34 is disposed in the second coolant flow path 32 and configured to operate on / off of the second coolant flow path 32.

[0197] The first valve 34 can be any type of valve that is electrically, hydraulically, or manually controlled, such as a ball valve, butterfly valve, or diaphragm valve. The first valve 34 can open or close the second coolant flow path 32. Depending on the needs, the first valve 34 can also control the flow rate of the second coolant flow path 32.

[0198] In this embodiment, by setting a first valve 34 in the second coolant flow path 32, the first valve 34 is used to realize the opening and closing of the second coolant flow path 32, so that the coolant in the liquid cooling circulation loop 30 can flow through the second heat exchanger or not flow through the second coolant flow path 32 as needed, thereby increasing the controllability of the liquid cooling circulation loop 30.

[0199] In some embodiments, the diameter of the pipe for circulating coolant in the first heat exchanger 21 is configured to be the same as or different from the diameter of the pipe for circulating coolant in the second heat exchanger 22.

[0200] The pipe diameter can be related to the specifications of the heat exchanger. By replacing heat exchangers of different specifications, the pipe diameter requirements of the thermal management system can be met. Here, pipe diameter mainly refers to the inner diameter of the pipe used to flow coolant, but for cases where the wall thickness is basically the same, it can also refer to the outer diameter. For example, the pipe of the first heat exchanger 21 can be set to Φ20, i.e., an outer diameter of 20mm, and the pipe of the second heat exchanger can be set to Φ15, i.e., an outer diameter of 15mm.

[0201] Using a first heat exchanger 21 and a second heat exchanger 22 with the same pipe diameter simplifies assembly and eliminates the need for some variable diameter components. However, using a first heat exchanger 21 and a second heat exchanger 22 with different pipe diameters allows for the distribution of coolant flow through the first coolant flow path 31 and the second coolant flow path 32, respectively, which can effectively meet the thermal management requirements of the battery 12 and the energy storage converter 13.

[0202] In Figure 2, the liquid cooling circulation loop 30 may further include a pump 36, an expansion tank 37, and sensors for sensing parameters such as temperature and pressure. The arrows in Figure 2 indicate the flow direction of the coolant in the liquid cooling circulation loop 30 driven by the pump 36. The expansion tank 37 can compensate for the volume expansion or contraction of the coolant in the liquid cooling circulation loop 30 due to temperature changes and can maintain the pressure stability of the liquid cooling circulation loop 30.

[0203] The first sensor 38 can be located upstream of the first and second coolant flow paths connected in parallel to sense parameters such as coolant temperature and pressure before entering the first and second heat exchangers. The second sensor 39 can be located downstream of the first and second coolant flow paths connected in parallel to sense parameters such as coolant temperature and pressure after entering the first and second heat exchangers.

[0204] Figure 3 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.

[0205] Referring to Figure 3, in some embodiments, the thermal management system 11 further includes a liquid cooling circulation bypass 50. The liquid cooling circulation bypass 50 is connected to the liquid cooling circulation loop 30, wherein the liquid cooling circulation bypass 50 includes a third heat exchanger 51 and a second valve 52. The third heat exchanger 51 is configured to dissipate heat from the coolant flowing through the liquid cooling circulation bypass 50, and the second valve 52 is connected in series with the third heat exchanger 51 and is configured to operate the on / off state of the liquid cooling circulation bypass 50.

[0206] The third 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 third heat exchanger 51 through air cooling, liquid cooling, or other methods. For example, the third heat exchanger 51 may include a coolant heat dissipation container 511, which dissipates heat from the coolant through air cooling. The second valve 52 can be an electrically controlled, hydraulically controlled, or manually controlled valve, such as a ball valve, butterfly valve, or diaphragm valve. The second valve 52 can open or close the liquid cooling circulation bypass 50. As needed, the second valve 52 can also control the flow rate of the liquid cooling circulation bypass 50.

[0207] In this embodiment, by setting a second valve 52 in the liquid cooling circulation bypass 50, the liquid cooling circulation bypass 50 can be opened and closed using the second valve 52. This allows the coolant in the liquid cooling circulation loop 30 to be partially diverted to the liquid cooling circulation bypass 50 for heat exchange as needed, or not diverted to the liquid cooling circulation bypass 50 for heat exchange, thereby increasing the controllability of the coolant circulation system.

[0208] In Figure 3, the third heat exchanger 51 may include a coolant heat dissipation container 511, and the thermal management system 11 may also include a fan 45. The coolant heat dissipation container 511 can be placed in the airflow path driven by the fan 45 so that the fan 45 can air-cool the coolant heat dissipation container 511, thereby effectively improving the air-cooling efficiency. The fan 45 may include axial flow, centrifugal, mixed flow, or other types of fans.

[0209] In Figure 3, the arrows in the liquid cooling circulation bypass 50 indicate the flow direction of the coolant in the liquid cooling circulation bypass 50 driven by the pump 36, and the arrows on both sides of the fan 45 indicate the airflow direction. The two ends of the liquid cooling circulation bypass 50 can be connected to different positions in the liquid cooling circulation loop 30, and the connection positions are located outside the first coolant flow path 31 and the second coolant flow path 32.

[0210] Figure 4 is a schematic diagram of control signal connections according to an embodiment of the thermal management system of the energy storage system of this disclosure.

[0211] Referring to Figures 3 and 4, in some embodiments, the thermal management system 11 further includes: a heater 33 disposed in the first coolant flow path 31 and a first valve 34 disposed in the second coolant flow path 32; wherein, the energy storage system 10 further includes a processor 60. The processor 60 is configured to operate the opening and closing states of the first valve 34, the second valve 52, and the heater 33 according to the operating mode of the thermal management system 11.

[0212] The processor 60 can communicate with the first valve 34, the second valve 52, and the heater 33 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 (ASICs), field-programmable gate arrays (FPGAs), 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.

[0213] In this embodiment, the processor 60 can operate the opening and closing states of the first valve 34, the second valve 52 and the heater 33 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.

[0214] In Figure 4, for an embodiment of the thermal management system 11 that includes a fan 45, the processor 60 can also be connected to the fan 45 to control the operation of the fan 45 according to the operating mode of the thermal management system 11, such as controlling the start, stop or operating power of the fan 45.

[0215] 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.

[0216] Referring to Figure 5, in some embodiments, the thermal management system 11 further includes a refrigerant circulation loop 40. The refrigerant circulation loop 40 has an evaporator 44; wherein the refrigerant circulation loop 40 is configured to circulate refrigerant and exchange heat with the liquid-cooled circulation loop 30 through the evaporator 44, the liquid-cooled circulation loop 30 having heat exchange lines 35 that pass through the evaporator 44 and are connected to the first and second parallel cooling liquid flow paths 31 and 32.

[0217] The refrigerant circulation loop 40 enables the circulation of refrigerant fluid, achieving heat transfer 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 liquid cooling circulation loop 30, achieving heat transfer through heat exchange.

[0218] The heat exchange pipe 35, passing through the evaporator 44, allows for heat exchange with the refrigerant flowing through the evaporator 44. The heat absorption by the evaporator 44 cools the coolant flowing in the heat exchange pipe 35. In Figure 5, the heat exchange pipe 35 is shown as a dashed line within the evaporator 44. This heat exchange pipe 35 can be located downstream of the pump 36 and upstream of the parallel-connected first coolant flow path 31 and second coolant flow path 32. The evaporator 44 can be a plate heat exchanger evaporator or other types of evaporators, such as a shell-and-tube evaporator.

[0219] In this embodiment, heat exchange between the refrigerant circulation loop 40 and the liquid cooling circulation loop 30 provides cooling or heating to the coolant in the refrigerant circulation loop 40, which improves the thermal management efficiency of the refrigerant circulation loop 40 and enhances the configuration flexibility for different thermal management needs. Furthermore, the refrigerant circulation is achieved through the refrigerant circulation loop 40, and heat exchange occurs between the evaporator 44 and the liquid cooling circulation loop 30 via the heat exchange pipe 35 of the evaporator 44, thereby effectively reducing the temperature of the coolant flowing in the liquid cooling circulation loop 30 and meeting the cooling requirements of the thermal management system.

[0220] In Figure 5, 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 under the drive of 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.

[0221] Additionally, in Figure 5, the fan 45 in the thermal management system 11 can also be used for air cooling of the condenser 42 to improve its efficiency. A first pressure sensor 47 for sensing the intake pressure of the compressor 41 and a second pressure sensor 48 for sensing the discharge pressure of the compressor 41 can also be installed in the refrigerant circulation loop 40. The refrigerant circulation loop 40 in Figure 5 can also include a receiver 46, which can store excess refrigerant and adjust the refrigerant flow rate in the refrigerant circulation loop according to changes in system load.

[0222] Figure 6 is a schematic diagram of the structure of the thermal management system according to some embodiments of the energy storage system of the present disclosure.

[0223] Compared to Figure 5, the embodiment shown in Figure 6 includes not only the refrigerant circulation loop 40 but also a liquid-cooled circulation bypass 50. Referring to Figure 6, in some embodiments, the thermal management system 11 further includes a liquid-cooled circulation bypass 50. The liquid-cooled circulation bypass 50 is connected in parallel with the heat exchange pipeline 35; wherein, the liquid-cooled circulation bypass 50 includes: a third heat exchanger 51 and a second valve 52, the third heat exchanger 51 being configured to dissipate heat from the coolant flowing through the liquid-cooled circulation bypass 50, and the second valve 52 being connected in series with the third heat exchanger 51 and configured to operate the on / off state of the liquid-cooled circulation bypass 50.

[0224] The third 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 third heat exchanger 51 through air cooling, liquid cooling, or other methods. For example, the third heat exchanger 51 may include a coolant heat dissipation container 511, which dissipates heat from the coolant through air cooling. The second valve 52 can be an electrically controlled, hydraulically controlled, or manually controlled valve, such as a ball valve, butterfly valve, or diaphragm valve. The second valve 52 can open or close the liquid cooling circulation bypass 50. As needed, the second valve 52 can also control the flow rate of the liquid cooling circulation bypass 50.

[0225] In this embodiment, the thermal management system, which includes a refrigerant circulation loop 40 and a liquid-cooled circulation bypass 50, offers greater configuration flexibility and meets more diverse thermal management needs. Furthermore, by providing a second valve 52 in the liquid-cooled circulation bypass 50, the system can control the flow of coolant from the liquid-cooled circulation loop 30 to the liquid-cooled circulation bypass 50 for heat exchange, or vice versa, thereby increasing the controllability of the coolant circulation system.

[0226] Referring to Figure 6, in some embodiments, the refrigerant circulation loop 40 further includes a condenser 42, and the third heat exchanger 51 includes a coolant heat dissipation container 511 disposed adjacent to the condenser 42; wherein, the thermal management system 11 further includes a fan 45. The fan 45 is configured to provide air cooling for the condenser 42 and the coolant heat dissipation container 511.

[0227] 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.

[0228] In this embodiment, by placing the condenser 42 adjacent to the coolant heat dissipation container 511, and utilizing the airflow driven by the fan 45, the condenser 42 and the coolant heat dissipation container 511 are simultaneously cooled by air, which helps to improve air cooling efficiency and reduce energy consumption.

[0229] Referring to the airflow direction fd shown in Figure 6, 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.

[0230] Typically, 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, and the temperature rises after absorbing heat. It can then continue to absorb heat after passing through the condenser 42, thereby achieving the air cooling effect on the condenser 42.

[0231] In this embodiment, 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 effect of both the coolant heat dissipation container 511 and the condenser 42.

[0232] The above-described thermal management system embodiments of this disclosure can achieve multiple operating modes to meet the thermal management needs of batteries and energy storage converters in energy storage systems under different conditions.

[0233] 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.

[0234] Referring to FIG7, in some embodiments, the thermal management system 11 further includes: a heater 33 disposed in the first coolant flow path 31 and a first valve 34 disposed in the second coolant flow path 32; wherein, the energy storage system 10 further includes a processor 60 configured to, when the thermal management system 11 is in a first operating mode M1, open the first valve 34, open the second valve 52 and close the heater 33.

[0235] Figure 7 illustrates the media circulation and control relationships of the thermal management system shown in Figure 6 in the first operating mode. In Figure 7, both the first valve 34 and the second valve 52 are bolded to indicate that they are in the open state, and the lines of the liquid cooling circulation loop 30 and the liquid cooling circulation bypass 50 are bolded to indicate that there is media flow. At this time, the open first valve 34 allows coolant to enter the second heat exchanger 22 through the first valve 34, and the open second valve 52 allows coolant to enter the liquid cooling circulation bypass 50 through the second valve 52. The heater 33 is represented by a dashed line, indicating that it is closed and does not perform a heating function.

[0236] In the first operating mode M1, pump 36 drives the coolant to flow through the first coolant flow path 31 and the second coolant flow path 32, which are connected in parallel, thus cooling the battery 12 and the energy storage converter 13 without using heater 33. The coolant, after absorbing heat, flows back to pump 36. During this process, a portion of the coolant flows from the liquid-cooled circulation loop 30 into the liquid-cooled circulation bypass 50, dissipates heat through the third heat exchanger 51, and then flows back to the liquid-cooled circulation loop 30, resulting in coolant with an even lower temperature.

[0237] In this embodiment, when the thermal management system 11 is in the first working mode M1, the processor 60 opens the first valve 34, the second valve 52, and the heater 33. This allows the liquid cooling circulation bypass 50 to be fully utilized to assist the liquid cooling circulation loop 30 in improving the cooling effect of the battery 12 and the energy storage converter 13, thereby meeting the cooling requirements of the battery 12 and the energy storage converter 13.

[0238] Referring to FIG7, in some embodiments, the third heat exchanger 51 includes a coolant heat dissipation container 511, and the thermal management system 11 further includes a fan 45 configured to perform air cooling on the coolant heat dissipation container 511; the processor 60 is configured to turn on the fan 45 when the thermal management system 11 is in the first operating mode.

[0239] In Figure 7, the thickened line of fan 45 indicates that fan 45 is in the on state.

[0240] In this embodiment, the fan 45 can improve the air cooling efficiency of the coolant heat dissipation container 511 in the first working mode and enhance the cooling effect of the liquid cooling circulation bypass 50 on the liquid cooling circulation loop 30 to improve the cooling effect of the battery 12 and the energy storage converter 13.

[0241] In some embodiments, the processor 60 is configured to switch the thermal management system 11 to the first operating mode in response to an ambient temperature being lower than or equal to a first preset temperature.

[0242] 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 first preset temperature can be set according to the actual situation. For example, the value of the first preset temperature can be set in [-5℃, 10℃], and can be selected as -5℃, -2℃, 0℃, 3℃, 5℃, 7.2℃ or 10℃, etc.

[0243] In this embodiment, by comparing the ambient temperature with a threshold, the thermal management system 11 switches to the first working mode M1, which can meet the situation where the battery 12 and the energy storage converter 13 have lower cooling requirements, saving the energy consumed by using the refrigerant circulation loop 40, which is beneficial to saving energy consumption.

[0244] Figure 8 is a schematic diagram of the medium circulation in the second operating mode of the thermal management system according to an embodiment of the energy storage system of the present disclosure. Figure 9 is a schematic diagram of the medium circulation in the third operating mode of the thermal management system according to an embodiment of the energy storage system of the present disclosure.

[0245] Referring to Figures 8 and 9, in some embodiments, the thermal management system 11 further includes: a heater 33 disposed in the first coolant flow path 31 and a first valve 34 disposed in the second coolant flow path 32; wherein, the energy storage system 10 further includes a processor 60 configured to, when the thermal management system 11 is in a second operating mode M2, close the first valve 34, close the second valve 52 and turn on the heater 33, and when the thermal management system 11 is in the third operating mode M3, close the first valve 34, close the second valve 52 and turn off the heater 33.

[0246] In Figures 8 and 9, the first valve 34 and the second valve 52 are both represented by dashed lines to indicate that they are in the closed state. At this time, the corresponding second coolant flow path 32 and liquid cooling circulation bypass 50 are also in the open state. The heater 33 is indicated by bold in Figure 8 to indicate that it is on and playing a heating role, and by dashed lines in Figure 9 to indicate that it is closed and does not play a heating role.

[0247] In the second operating mode M2, pump 36 drives the coolant to flow through the first coolant flow path 31, without passing through the second coolant flow path 32 and the liquid cooling circulation bypass 50. While flowing through the first coolant flow path 31, the coolant is heated by heater 33. In the third operating mode M3, pump 36 drives the coolant to flow through the first coolant flow path 31, without passing through the second coolant flow path 32 and the liquid cooling circulation bypass 50. While flowing through the first coolant flow path 31, the coolant is not heated by heater 33.

[0248] 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 not easily affected by the low temperature 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.

[0249] In this embodiment, when the thermal management system 11 is in the second operating mode M2, the processor 60 closes the first valve 34 and the second valve 52, and turns on the heater 33. The heating effect of the heater 33 allows the higher-temperature coolant to raise the temperature of the battery 12, improving the battery's performance, energy consumption, and efficiency. Furthermore, closing the first valve 34 directs the coolant to the first heat exchanger 21, improving the battery's heat exchange efficiency. Closing the second valve 52 eliminates the need for the coolant to pass through the liquid cooling bypass 50 for heat dissipation, thus reducing the heating load on the heater 33.

[0250] For coolants at higher temperatures, when the thermal management system 11 is in the third operating mode M2, the processor 60 closes the first valve 34, the second valve 52, and the heater 33. This effectively increases the temperature of the battery 12 without the need for the heater 33 to heat it, thereby improving the battery 12's performance, energy consumption, and efficiency.

[0251] In some embodiments, the processor 60 is configured to switch the thermal management system 11 to the second operating mode in response to the temperature of the battery 12 being lower than or equal to a second preset temperature and the temperature of the coolant being lower than or equal to a third preset temperature, and to switch the thermal management system 11 to the third operating mode in response to the temperature of the battery 12 being lower than or equal to the second preset temperature and the temperature of the coolant being higher than the third preset temperature, wherein the temperature of the coolant is the coolant temperature of the flow path of the liquid cooling circulation loop 30 upstream of the parallel-connected first coolant flow path 31 and second coolant flow path 32, and the third preset temperature is higher than the second preset temperature.

[0252] 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 flow path upstream of the first coolant flow path 31 and the second coolant flow path 32 in the parallel-connected liquid cooling circulation loop 30, which can be obtained by the first sensor 38 as shown in Figures 8 and 9. The values ​​of the second preset temperature and the third preset temperature can be set according to the actual situation. The third preset temperature is higher than the second preset temperature. For example, the value of the second preset temperature is set in [12℃, 20℃], which can be selected as 12℃, 14℃, 15℃, 17℃, 18.5℃ or 20℃, etc. The value of the third preset temperature is set in [22℃, 38℃], which can be selected as 22℃, 23℃, 25℃, 28℃, 30℃, 35℃ or 38℃, etc.

[0253] In this embodiment, by comparing the battery temperature and coolant temperature with threshold values, the thermal management system 11 can switch to the second operating mode M2 ​​to meet the heating requirement of the battery 12 when the temperature is low, and raise the temperature of the coolant by a heater when the coolant temperature is low, so that the battery heating can proceed smoothly. Conversely, 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 requirement of the battery 12 when the temperature is low, and eliminate the need for heater heating when the coolant temperature is high, thereby saving energy.

[0254] Figure 10 is a schematic diagram of the medium circulation in the fourth operating mode of the thermal management system according to an embodiment of the energy storage system of the present disclosure. 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.

[0255] Referring to Figures 10 and 11, in some embodiments, the thermal management system 11 further includes: a heater 33 disposed in the first coolant flow path 31 and a first valve 34 disposed in the second coolant flow path 32; wherein, the energy storage system 10 further includes a processor 60 configured to, in the fourth operating mode of the thermal management system 11, open the first valve 34, close the second valve 52 and open the heater 33, and in the fifth operating mode of the thermal management system 11, open the first valve 34, close the second valve 52 and close the heater 33.

[0256] In Figures 10 and 11, the first valve 34 is represented by a bold line to indicate that it is in the open state, and the second valve 52 is represented by a dashed line to indicate that it is in the closed state. The liquid cooling circulation loop 30 is represented by a bold line to indicate that there is medium flowing. The heater 33 is represented by a bold line in Figure 10 to indicate that it is in the open state and is performing a heating function, and by a dashed line in Figure 11 to indicate that it is in the closed state and is not performing a heating function.

[0257] In the fourth operating mode M4, pump 36 drives the coolant to flow through the first coolant flow path 31 and the second coolant flow path 32, without flowing through the liquid cooling circulation bypass 50, and the coolant is heated by heater 33 when flowing through the first coolant flow path 31. In the fifth operating mode M5, pump 36 drives the coolant to flow through the first coolant flow path 31 and the second coolant flow path 32, without flowing through the liquid cooling circulation bypass 50, and the coolant is not heated by heater 33 when flowing through the first coolant flow path 31.

[0258] When the battery 12 is at a low temperature, its performance, energy consumption, and efficiency will be affected by the low temperature. Conversely, when the energy storage converter 13 is at a high temperature, its temperature needs to be reduced to ensure its operational stability. Therefore, when heating the battery 12 is required, cooling of the energy storage converter 13 also needs to be considered.

[0259] In this embodiment, when the thermal management system 11 is in the fourth operating mode M4, the processor 60 opens the first valve 34, closes the second valve 52, and turns on the heater 33. The heating effect of the heater 33 raises the temperature of the coolant entering the first coolant flow path 31, thereby increasing the temperature of the battery 12 and improving its performance, energy consumption, and efficiency. Meanwhile, the coolant entering the second coolant flow path 32 cools the energy storage converter 13. Furthermore, by closing the second valve 52, the coolant does not need to pass through the liquid cooling circulation bypass 50 for heat dissipation, thus avoiding an increase in the heating load on the heater 33.

[0260] When the thermal management system 11 is in the fifth working mode M5, the processor 60 opens the first valve 34, closes the second valve 52, and shuts down the heater 33. The coolant plays different roles in the first coolant flow path 31 and the second coolant flow path 32. The coolant entering the first coolant flow path 31 heats the battery 12, improving its performance, energy consumption, and efficiency. The coolant entering the second coolant flow path 32 cools the energy storage converter 13, and the heater 33 is not turned on to save energy consumption.

[0261] In some embodiments, the processor 60 is configured to switch the thermal management system 11 to the fourth operating mode in response to the temperature of the energy storage converter 13 being higher than or equal to a fourth preset temperature and the temperature of the coolant being lower than the fifth preset temperature, and to switch the thermal management system 11 to the fifth operating mode in response to the temperature of the energy storage converter 13 being higher than or equal to the fourth preset temperature and the temperature of the coolant being lower than or equal to the fifth preset temperature and higher than or equal to a sixth preset temperature, wherein the temperature of the coolant is the coolant temperature of the flow path of the liquid cooling circulation loop 30 upstream of the parallel-connected first coolant flow path 31 and second coolant flow path 32, the fifth preset temperature being lower than the sixth preset temperature, and the sixth preset temperature being lower than the fourth preset temperature.

[0262] 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 temperature of the coolant is the coolant temperature of the flow path upstream of the first coolant flow path 31 and the second coolant flow path 32 in the parallel-connected liquid cooling circulation loop 30, which can be obtained by the first sensor 38 in Figures 10 and 11. The values ​​of the fourth, fifth, and sixth preset temperatures can be set according to actual conditions. The fifth preset temperature is lower than the sixth preset temperature, and the sixth preset temperature is lower than the fourth preset temperature. For example, the fourth preset temperature can be set in [50℃, 80℃], and can be selected as 50℃, 58℃, 62℃, 65℃, 72℃, or 80℃, etc. The fifth preset temperature can be set in [26℃, 34℃], and can be selected as 26℃, 28℃, 30℃, 31℃, 32℃, 33℃, or 34℃, etc. The sixth preset temperature can be set in [36℃, 44℃], and can be selected as 36℃, 38℃, 40℃, 41℃, 42℃, 43℃, or 44℃, etc.

[0263] In this embodiment, by comparing the temperatures of the energy storage converter 13 and the coolant with threshold values, the thermal management system 11, when switching to the fourth operating mode M4, can meet the cooling needs of the energy storage converter 13 when it is hot, and raises the temperature of the coolant by the heater 33 when the coolant temperature is low, allowing the battery to heat up smoothly. Conversely, by comparing the temperatures of the energy storage converter 13 and the coolant with threshold values, the thermal management system 11, when switching to the fifth operating mode M5, can meet the cooling needs of the energy storage converter 13 when it is hot, and eliminates the need for heater 33 when the coolant temperature is high, thus saving energy. Furthermore, the heat released by the energy storage converter 13 into the coolant can be recovered as waste heat and provided to the battery 12 to raise the battery temperature, saving energy used for heating.

[0264] Referring to Figures 7-11, in some embodiments, the thermal management system 11 further includes a refrigerant circulation loop 40. The refrigerant circulation loop 40 is configured to circulate refrigerant and exchange heat with the liquid cooling circulation loop 30; wherein the refrigerant circulation loop 40 has an evaporator 44; the liquid cooling circulation loop 30 has a heat exchange pipe 35 that passes through the evaporator 44 and is connected in parallel with the first coolant flow path 31 and the second coolant flow path 32, and the liquid cooling circulation bypass 50 is connected in parallel with the heat exchange pipe 35; the processor 60 is configured to operate the opening and closing state of the refrigerant circulation loop 40 according to the operating mode of the thermal management system 11.

[0265] In Figures 7-11, the refrigerant circulation loop 40 may also include a compressor 41, a condenser 42, and a throttling device 43. For the thermal management system 11 containing the refrigerant circulation loop 40, the processor 60 can be signal-connected to the devices in the refrigerant circulation loop 40, such as communicating with the compressor 41 and the throttling device 43, to control the start and stop of the compressor 41 and to control the flow rate of the throttling device 43. The processor 60 can operate the opening and closing state of the refrigerant circulation loop 40 according to the operating mode of the thermal management system 11.

[0266] In this embodiment, the refrigerant circulation loop 40 is configured to achieve heat exchange with the liquid cooling circulation loop 30, and the processor 60 controls the opening and closing state of the refrigerant circulation loop 40 to meet the different cooling requirements of the thermal management system 11.

[0267] Referring to Figures 7-11, in some embodiments, the processor 60 is configured to shut down the refrigeration cycle of the refrigerant circulation loop 40 when the thermal management system 11 is in any of the first operating mode M1, the second operating mode M2, the third operating mode M3, the fourth operating mode M4, and the fifth operating mode M5.

[0268] In the various thermal management systems 11 shown in Figures 7-11, the battery 12 may have either a heating requirement or a relatively low cooling requirement. Therefore, the thermal management system 11 can save energy by shutting down the cooling cycle of the refrigerant circulation loop 40 while meeting the cooling or heating requirements of the battery 12. In other embodiments, the various embodiments of the thermal management systems 11 shown in Figures 7-11 may also omit the refrigerant circulation loop 40, thereby simplifying the control logic of the processor 60.

[0269] 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.

[0270] Referring to FIG12, in some embodiments, the processor 60 is configured to open the first valve 34, close the second valve 52 and close the heater 33, and start the refrigeration cycle of the refrigerant circulation loop 40 when the thermal management system 11 is in the sixth operating mode M6.

[0271] In Figure 12, the first valve 34 is represented by a bold line to indicate that it is in the open state, and the second valve 52 is represented by a dashed line to indicate that it is in the closed state. The lines of the liquid cooling circulation loop 30 and the refrigerant circulation loop 40 are represented by bold lines to indicate that there is medium flowing. The heater 33 is represented by a dashed line in Figure 12 to indicate that it is closed and does not perform a heating function.

[0272] In the sixth operating mode M6, pump 36 drives the coolant to flow through the first coolant flow path 31 and the second coolant flow path 32, without flowing through the liquid cooling circulation bypass 50. When flowing through the first coolant flow path 31, the coolant is not heated by heater 33. Meanwhile, compressor 41 drives the refrigerant to flow through condenser 42. The refrigerant enters evaporator 44 from condenser 42 through throttling device 43 and then flows back to compressor 41. The coolant in heat exchange pipeline 35 exchanges heat with the refrigerant in evaporator 44.

[0273] 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 sixth operating mode M6, the processor 60 opens the first valve 34, closes the second valve 52, and shuts down the heater 33, and activates the refrigerant circulation loop 40 to start the refrigeration cycle. This allows 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 second valve 52, the coolant does not need to pass through the liquid cooling circulation bypass 50 but instead flows directly through the heat exchange pipeline 35 for heat exchange with the refrigerant, which helps to improve the heat exchange efficiency of the evaporator 44.

[0274] In some embodiments, the processor 60 is configured to switch the thermal management system 11 to the sixth operating mode in response to the temperature of the coolant being higher than or equal to a seventh preset temperature, wherein the temperature of the coolant is the coolant temperature of the liquid cooling circulation loop 30 upstream of the parallel-connected first coolant flow path 31 and second coolant flow path 32.

[0275] Here, the coolant temperature refers to the coolant temperature in the upstream flow path of the liquid cooling circulation loop 30 in the parallel-connected first coolant flow path 31 and second coolant flow path 32, which can be sensed by the first sensor 38 in Figure 12. The value of the seventh preset temperature can be set according to actual conditions. For example, the value of the seventh preset temperature can be set in [36℃, 44℃], and can be selected as 36℃, 38℃, 40℃, 41℃, 42℃, 43℃, or 44℃, etc.

[0276] In this embodiment, by comparing the temperature of the coolant with a threshold, when the thermal management system 11 switches to the sixth working mode M6, 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 temperature of the coolant itself is high.

[0277] 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.

[0278] Referring to Figures 3-5, this disclosure provides a control method for an energy storage system 10 of any of the foregoing embodiments. The thermal management system 11 further includes: a heater 33 disposed in the first coolant flow path 31 and a first valve 34 disposed in the second coolant flow path 32. The energy storage system 10 also includes a processor 60. The control method includes: operating the opening and closing states of the first valve 34, the second valve 52 and the heater 33 according to the operating mode of the thermal management system 11.

[0279] The processor 60 can communicate with the first valve 34, the second valve 52, and the heater 33 via wired or wireless means to operate the opening and closing states of one or more of the first valve 34, the second valve 52, and the heater 33.

[0280] In this embodiment, the opening and closing states of the first valve 34, the second valve 52, and the heater 33 are operated according to the working mode of the thermal management system 11, which can satisfy the thermal management function played by the thermal management system 11 in different working modes.

[0281] Referring to Figure 7, in some embodiments, the steps of operating the opening and closing states of the first valve 34, the second valve 52, and the heater 33 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 first valve 34, opening the second valve 52, and closing the heater 33.

[0282] In this embodiment, when the thermal management system 11 is in the first working mode M1, the processor 60 opens the first valve 34, the second valve 52, and the heater 33. This allows the liquid cooling circulation bypass 50 to be fully utilized to assist the liquid cooling circulation loop 30 in improving the cooling effect of the battery 12 and the energy storage converter 13, thereby meeting the cooling requirements of the battery 12 and the energy storage converter 13.

[0283] Referring to Figure 7, in some embodiments, the third heat exchanger 51 includes a coolant heat dissipation container 511, and the thermal management system 11 further includes a fan 45 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 first operating mode M1, turning on the fan 45.

[0284] In this embodiment, the fan 45 can improve the air cooling efficiency of the coolant heat dissipation container 511 in the first working mode and enhance the cooling effect of the liquid cooling circulation bypass 50 on the liquid cooling circulation loop 30 to improve the cooling effect of the battery 12 and the energy storage converter 13.

[0285] In some embodiments, the control method further includes: in response to an ambient temperature being lower than or equal to a first preset temperature, switching the thermal management system 11 to the first operating mode M1.

[0286] In this embodiment, by comparing the ambient temperature with a threshold, the thermal management system 11 switches to the first working mode M1, which can meet the situation where the battery 12 and the energy storage converter 13 have lower cooling requirements, saving the energy consumed by using the refrigerant circulation loop 40, which is beneficial to saving energy consumption.

[0287] Referring to Figures 8 and 9, in some embodiments, the steps of operating the opening and closing states of the first valve 34, the second valve 52, and the heater 33 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 first valve 34, closing the second valve 52, and opening the heater 33; and when the thermal management system 11 is in the third operating mode M3, closing the first valve 34, closing the second valve 52, and closing the heater 33.

[0288] In this embodiment, when the thermal management system 11 is in the second operating mode M2, the first valve 34 and the second valve 52 are closed, and the heater 33 is turned on. The heating effect of the heater 33 allows the higher-temperature coolant to raise the temperature of the battery 12, thereby improving the performance, energy consumption, and efficiency of the battery 12. Moreover, by closing the first valve 34, the coolant flows to the first heat exchanger 21 in a concentrated manner, which helps to improve the efficiency of battery heat exchange. And 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 33.

[0289] For coolants at higher temperatures, when the thermal management system 11 is in the third operating mode M2, the first valve 34 is closed, the second valve 52 is closed, and the heater 33 is closed. This effectively increases the temperature of the battery 12 without the need for the heater 33 to heat it, thereby improving the battery 12's performance, energy consumption, and efficiency.

[0290] In some embodiments, the control method further includes: in response to the temperature of the battery 12 being lower than or equal to a second preset temperature and the temperature of the coolant being lower than or equal to a third preset temperature, switching the thermal management system 11 to the second operating mode M2; in response to the temperature of the battery 12 being lower than or equal to the second preset temperature and the temperature of the coolant being higher than the third preset temperature, switching the thermal management system 11 to the third operating mode M3; wherein the temperature of the coolant is the coolant temperature of the flow path of the liquid cooling circulation loop 30 upstream of the parallel-connected first coolant flow path 31 and second coolant flow path 32, and the third preset temperature is higher than the second preset temperature.

[0291] In this embodiment, by comparing the battery temperature and coolant temperature with threshold values, the thermal management system 11 can switch to the second operating mode M2 ​​to meet the heating requirement of the battery 12 when the temperature is low, and raise the temperature of the coolant by a heater when the coolant temperature is low, so that the battery heating can proceed smoothly. Conversely, 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 requirement of the battery 12 when the temperature is low, and eliminate the need for heater heating when the coolant temperature is high, thereby saving energy.

[0292] Referring to Figures 10 and 11, in some embodiments, the steps of operating the opening and closing states of the first valve 34, the second valve 52, and the heater 33 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, opening the first valve 34, closing the second valve 52, and opening the heater 33; and when the thermal management system 11 is in the fifth operating mode M5, opening the first valve 34, closing the second valve 52, and closing the heater 33.

[0293] In this embodiment, when the thermal management system 11 is in the fourth operating mode M4, the first valve 34 is opened, the second valve 52 is closed, and the heater 33 is turned on. The heating effect of the heater 33 can raise the temperature of the coolant entering the first coolant flow path 31, thereby increasing the temperature of the battery 12 and improving its performance, energy consumption, and efficiency. Meanwhile, the coolant entering the first coolant flow path 31 cools the energy storage converter 13. 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 33.

[0294] When the thermal management system 11 is in the fifth working mode M5, the first valve 34 is opened, the second valve 52 is closed, and the heater 33 is turned off. The coolant plays different roles in the first coolant flow path 31 and the second coolant flow path 32. The coolant entering the first coolant flow path 31 heats the battery 12, improving the performance, energy consumption, and efficiency of the battery 12. The coolant entering the second coolant flow path 32 cools the energy storage converter 13, and the heater 33 is not turned on to save energy consumption.

[0295] In some embodiments, the control method further includes: switching the thermal management system 11 to the fourth operating mode in response to the temperature of the energy storage converter 13 being higher than or equal to a fourth preset temperature and the temperature of the coolant being lower than the fifth preset temperature; and switching the thermal management system 11 to the fifth operating mode in response to the temperature of the energy storage converter 13 being higher than or equal to the fourth preset temperature and the temperature of the coolant being lower than or equal to the fifth preset temperature and higher than or equal to a sixth preset temperature; wherein the temperature of the coolant is the coolant temperature of the flow path of the liquid cooling circulation loop 30 upstream of the parallel-connected first coolant flow path 31 and second coolant flow path 32, the fifth preset temperature is lower than the sixth preset temperature, and the sixth preset temperature is lower than the fourth preset temperature.

[0296] In this embodiment, by comparing the temperatures of the energy storage converter 13 and the coolant with threshold values, the thermal management system 11, when switching to the fourth operating mode M4, can meet the cooling needs of the energy storage converter 13 when it is hot, and raises the temperature of the coolant by the heater 33 when the coolant temperature is low, allowing the battery to heat up smoothly. Conversely, by comparing the temperatures of the energy storage converter 13 and the coolant with threshold values, the thermal management system 11, when switching to the fifth operating mode M5, can meet the cooling needs of the energy storage converter 13 when it is hot, and eliminates the need for heater 33 when the coolant temperature is high, thus saving energy. Furthermore, the heat released by the energy storage converter 13 into the coolant can be recovered as waste heat and provided to the battery 12 to raise the battery temperature, saving energy used for heating.

[0297] Referring to Figures 7-11, in some embodiments, the thermal management system 11 further includes: a refrigerant circulation loop 40 configured to circulate refrigerant and exchange heat with the liquid cooling circulation loop 30; the refrigerant circulation loop 40 has an evaporator 44; the liquid cooling circulation loop 30 has a heat exchange pipe 35 that passes through the evaporator 44 and is connected in parallel with the first coolant flow path 31 and the second coolant flow path 32, and the liquid cooling circulation bypass 50 is connected in parallel with the heat exchange pipe 35. Accordingly, the control method further includes: operating the opening and closing state of the refrigerant circulation loop 40 according to the operating mode of the thermal management system 11.

[0298] In this embodiment, the refrigerant circulation loop 40 is configured to achieve heat exchange with the liquid cooling circulation loop 30, and to control the opening and closing state of the refrigerant circulation loop 40, so as to meet the different cooling requirements of the thermal management system 11.

[0299] In some embodiments, the step of operating the opening and closing state of the refrigerant circulation loop 40 according to the working mode of the thermal management system 11 includes: shutting down the refrigeration cycle of the refrigerant circulation loop 40 when the thermal management system 11 is in any of the first working mode M1, the second working mode M2, the third working mode M3, the fourth working mode M4 and the fifth working mode M5.

[0300] In the various thermal management systems 11 shown in Figures 7-11, the battery 12 may have a heating requirement or a relatively low cooling requirement. The thermal management system 11 can save energy by shutting down the refrigeration cycle of the refrigerant circulation loop 40 while meeting the cooling or heating requirements of the battery 12.

[0301] Referring to Figure 12, in some embodiments, the steps for controlling the opening and closing states of the first valve 34, the second valve 52, and the heater 33 according to the operating mode of the thermal management system 11 include: when the thermal management system 11 is in the sixth operating mode M6, opening the first valve 34, closing the second valve 52, and closing the heater 33; wherein, the steps for controlling the opening and closing states of 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 sixth operating mode M6, starting the refrigeration cycle of the refrigerant circulation loop 40.

[0302] In this embodiment, when the thermal management system 11 is in the sixth operating mode M6, the first valve 34 is opened, the second valve 52 is closed, and the heater 33 is turned off. The refrigerant circulation loop 40 is activated for refrigeration, allowing the coolant to cool down through heat exchange with the refrigerant in the loop 40. This more effectively cools the battery 12 and the energy storage converter 13. Furthermore, by closing the second valve 52, the coolant bypasses the liquid cooling circulation bypass 50 and instead flows directly through the heat exchange pipeline 35, which improves the heat exchange efficiency of the evaporator 44.

[0303] In some embodiments, the control method further includes: in response to the temperature of the coolant being higher than or equal to a seventh preset temperature, switching the thermal management system 11 to the sixth operating mode M6, wherein the temperature of the coolant is the coolant temperature of the flow path of the liquid cooling circulation loop 30 upstream of the parallel-connected first coolant flow path 31 and second coolant flow path 32.

[0304] In this embodiment, by comparing the temperature of the coolant with a threshold, when the thermal management system 11 switches to the sixth working mode M6, 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 temperature of the coolant itself is high.

[0305] In some specific embodiments, as shown in Figures 4-6, the energy storage system 10 includes a thermal management system 11, a battery 12, and an energy storage converter 13. The thermal management system 11 includes a first heat exchanger 21, a second heat exchanger 22, a liquid-cooled circulation loop 30, a refrigerant circulation loop 40, a liquid-cooled circulation bypass 50, and a processor 60. The first heat exchanger 21 is used for heat exchange with the battery 12, and the second heat exchanger 22 is used for heat exchange with the energy storage converter 13. The liquid-cooled circulation loop 30 has a first coolant flow path 31 and a second coolant flow path 32 connected in parallel. The first heat exchanger 21 is located in the first coolant flow path 31, and the second heat exchanger 22 is located in the second coolant flow path 32. The liquid-cooled circulation loop 30 also includes a heater 33 located in the first coolant flow path 31 and a first valve 34 located in the second coolant flow path 32.

[0306] The refrigerant circulation loop 40 has a compressor 41, a condenser 42, a throttling device 43 and an evaporator 44; the liquid cooling circulation loop 30 has a heat exchange pipe 35 that passes through the evaporator 44 and is connected to the first coolant flow path 31 and the second coolant flow path 32 in parallel.

[0307] The liquid cooling circulation bypass 50 is connected in parallel with the heat exchange pipeline 35 and includes a third heat exchanger 51 and a second valve 52. The third heat exchanger 51 is configured to dissipate heat from the coolant flowing through the liquid cooling circulation bypass 50. The second valve 52 is connected in series with the third heat exchanger 51 and is configured to operate the opening and closing of the liquid cooling circulation bypass 50.

[0308] The third heat exchanger 51 includes a coolant heat dissipation container 511, and the condenser 42 is disposed adjacent to the coolant heat dissipation container 511. The thermal management system 11 also includes a fan 45, configured to provide air cooling for the condenser 42 and the coolant heat dissipation container 511. The coolant heat dissipation container 511 is located upstream of the condenser 42 along the airflow direction fd of the fan 45.

[0309] The processor 60 is signal-connected to the first valve 34, the second valve 52 and the heater 33, and is configured to operate the opening and closing states of the first valve 34, the second valve 52 and the heater 33 according to the operating mode of the thermal management system 11.

[0310] 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.

[0311] 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.

[0312] 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: a battery (12) for storing and releasing energy; an energy storage converter (13) for connecting a power supply and the battery (12); and a thermal management system (11); wherein the thermal management system (11) comprises: a first heat exchanger (21) for heat exchange with the battery (12); a second heat exchanger (22) for heat exchange with the energy storage converter (13); and a liquid cooling circulation loop (30) having a first cooling liquid flow path (31) and a second cooling liquid flow path (32) in parallel communication; wherein the first heat exchanger (21) is provided in the first cooling liquid flow path (31), and the second heat exchanger (22) is provided in the second cooling liquid flow path (32). The liquid cooling circulation loop (30) further comprises:

2. The energy storage system (10) of claim 1, wherein, a heater (33) provided in the first cooling liquid flow path (31) and configured to heat the cooling liquid flowing into the first heat exchanger (21). The liquid cooling circulation loop (30) further comprises:

3. The energy storage system (10) according to any of claims 1-2, wherein, a first valve (34) provided in the second cooling liquid flow path (32) and configured to operate the on-off of the second cooling liquid flow path (32). The pipe diameter of the pipe for flowing the cooling liquid of the first heat exchanger (21) is configured to be the same as or different from the pipe diameter of the pipe for flowing the cooling liquid of the second heat exchanger (22).

4. The energy storage system (10) according to any one of claims 1-3, wherein, The thermal management system (11) further comprises:

5. The energy storage system (10) according to any one of claims 1-4, wherein, a refrigerant circulation loop (40) having an evaporator (44); wherein the refrigerant circulation loop (40) is configured to realize refrigerant circulation and exchange heat with the liquid cooling circulation loop (30) through the evaporator (44), and the liquid cooling circulation loop (30) has a heat exchange pipe (35) passing through the evaporator (44) and communicating with the first cooling liquid flow path (31) and the second cooling liquid flow path (32) in parallel communication. The thermal management system (11) further comprises:

6. The energy storage system (10) of claim 5, wherein, a liquid cooling circulation bypass (50) in parallel communication with the heat exchange pipe (35); wherein the liquid cooling circulation bypass (50) comprises a third heat exchanger (51) configured to dissipate heat from the cooling liquid flowing through the liquid cooling circulation bypass (50), and a second valve (52) in series communication with the third heat exchanger (51) and configured to operate the on-off of the liquid cooling circulation bypass (50). The refrigerant circulation loop (40) further has a condenser (42), and the third heat exchanger (51) comprises a cooling liquid heat dissipation container (511) provided adjacent to the condenser (42); 7. The energy storage system (10) of claim 6, wherein, wherein the thermal management system (11) further comprises: a fan (45) configured to air cool the condenser (42) and the cooling liquid heat dissipation container (511). The cooling liquid heat dissipation container (511) is located upstream of the condenser (42) along the airflow direction (fd) of the fan (45).

8. The energy storage system (10) of claim 7, wherein, The thermal management system (11) further comprises:

9. The energy storage system (10) of claims 1-5, wherein, a liquid cooling circulation bypass (50) in communication with the liquid cooling circulation loop (30); ​ The liquid cooling circulation bypass (50) comprises a third heat exchanger (51) configured to dissipate heat of the cooling liquid flowing through the liquid cooling circulation bypass (50), and a second valve (52) in series communication with the third heat exchanger (51) and configured to operate on / off of the liquid cooling circulation bypass (50).

10. The energy storage system (10) of claim 9, wherein, The thermal management system (11) further comprises a heater (33) arranged in the first cooling liquid flow path (31) and a first valve (34) arranged in the second cooling liquid flow path (32); The energy storage system (10) further comprises: The processor (60) is configured to, when the thermal management system (11) is in the first working mode, open the first valve (34), open the second valve (52), and close the heater (33).

11. The energy storage system (10) of claim 10, wherein, The third heat exchanger (51) comprises a cooling liquid heat dissipation container (511), and the thermal management system (11) further comprises a fan (45) configured to air cool the cooling liquid heat dissipation container (511); the processor (60) is configured to, when the thermal management system (11) is in the first working mode, open the fan (45).

12. The energy storage system (10) according to claim 10 or 11, wherein The processor (60) is configured to, in response to an ambient temperature being lower than or equal to a first preset temperature, switch the thermal management system (11) to the first working mode.

13. The energy storage system (10) according to any of claims 9-12, wherein, The thermal management system (11) further comprises a heater (33) arranged in the first cooling liquid flow path (31) and a first valve (34) arranged in the second cooling liquid flow path (32); The energy storage system (10) further comprises: The processor (60) is configured to, when the thermal management system (11) is in the second working mode, close the first valve (34), close the second valve (52), and open the heater (33), and when the thermal management system (11) is in the third working mode, close the first valve (34), close the second valve (52), and close the heater (33).

14. The energy storage system (10) of claim 13, wherein, The processor (60) is configured to, in response to a temperature of the battery (12) being lower than or equal to a second preset temperature and a temperature of the cooling liquid being lower than or equal to a third preset temperature, switch the thermal management system (11) to the second working mode, and in response to the temperature of the battery (12) being lower than or equal to the second preset temperature and the temperature of the cooling liquid being higher than the third preset temperature, switch the thermal management system (11) to the third working mode, wherein the temperature of the cooling liquid is a cooling liquid temperature of a flow path upstream of the first cooling liquid flow path (31) and the second cooling liquid flow path (32) in the parallel communication, and the third preset temperature is higher than the second preset temperature.

15. An energy storage system (10) according to any of claims 9-14, wherein, The thermal management system (11) further comprises a heater (33) arranged in the first cooling liquid flow path (31) and a first valve (34) arranged in the second cooling liquid flow path (32); The energy storage system (10) further comprises: The processor (60) is configured to, when the thermal management system (11) is in a fourth working mode, open the first valve (34), close the second valve (52) and open the heater (33), and when the thermal management system (11) is in a fifth working mode, open the first valve (34), close the second valve (52) and close the heater (33).

16. The energy storage system (10) of claim 15, wherein, The processor (60) is configured to, in response to the temperature of the energy storage converter (13) being higher than or equal to a fourth preset temperature and the temperature of the cooling liquid being lower than the fifth preset temperature, switch the thermal management system (11) to the fourth working mode, and in response to the temperature of the energy storage converter (13) being higher than or equal to the fourth preset temperature, the temperature of the cooling liquid being lower than or equal to the fifth preset temperature and higher than or equal to a sixth preset temperature, switch the thermal management system (11) to the fifth working mode, wherein the temperature of the cooling liquid is the cooling liquid temperature of the flow path upstream of the liquid cooling circulation loop (30) in the parallel communication first cooling liquid flow path (31) and the second cooling liquid flow path (32), the fifth preset temperature is lower than the sixth preset temperature, and the sixth preset temperature is lower than the fourth preset temperature.

17. An energy storage system (10) according to any of claims 10-16, wherein, The thermal management system (11) further comprises: A refrigerant circulation loop (40) configured to realize refrigerant circulation and exchange heat with the liquid cooling circulation loop (30); The refrigerant circulation loop (40) has an evaporator (44); the liquid cooling circulation loop (30) has a heat exchange pipeline (35) passing through the evaporator (44) and communicating with the parallel communication first cooling liquid flow path (31) and the second cooling liquid flow path (32), and the liquid cooling circulation bypass (50) is in parallel communication with the heat exchange pipeline (35); the processor (60) is configured to operate the opening and closing state of the refrigerant circulation loop (40) according to the working mode of the thermal management system (11).

18. The energy storage system (10) of claim 17, wherein, The processor (60) is configured to, when the thermal management system (11) is in any one of a first working mode, a second working mode, a third working mode, a fourth working mode and a fifth working mode, close the refrigeration cycle of the refrigerant circulation loop (40).

19. The energy storage system (10) according to claim 17 or 18, wherein The processor (60) is configured to, when the thermal management system (11) is in a sixth working mode, open the first valve (34), close the second valve (52) and close the heater (33), and open the refrigeration cycle of the refrigerant circulation loop (40).

20. The energy storage system (10) of claim 19, wherein, The processor (60) is configured to, in response to the temperature of the cooling liquid being higher than or equal to a seventh preset temperature, switch the thermal management system (11) to the sixth working mode, and the temperature of the cooling liquid is the cooling liquid temperature of the flow path upstream of the liquid cooling circulation loop (30) in the parallel communication first cooling liquid flow path (31) and the second cooling liquid flow path (32).

21. A method of controlling an energy storage system (10) according to any of claims 9-20, said thermal management system (11) further comprising: The heater (33) arranged in the first coolant flow path (31) and the first valve (34) arranged in the second coolant flow path (32), the energy storage system (10) further comprises a processor (60); wherein the control method comprises: According to the working mode of the thermal management system (11), the opening and closing states of the first valve (34), the second valve (52) and the heater (33) are operated.

22. The control method according to claim 21, wherein According to the working mode of the thermal management system (11), the opening and closing states of the first valve (34), the second valve (52) and the heater (33) are operated. When the thermal management system (11) is in the first working mode, the first valve (34) is opened, the second valve (52) is opened, and the heater (33) is closed.

23. The control method according to claim 22, wherein The third heat exchanger (51) comprises a coolant heat dissipation container (511), and the thermal management system (11) further comprises a fan (45) configured to air cool the coolant heat dissipation container (511); The control method further comprises: When the thermal management system (11) is in the first working mode, the fan (45) is turned on.

24. The control method of claim 22 or 23, further comprising: In response to the ambient temperature being lower than or equal to a first preset temperature, the thermal management system (11) is switched to the first working mode.

25. The control method according to any one of claims 21-24, wherein, According to the working mode of the thermal management system (11), the opening and closing states of the first valve (34), the second valve (52) and the heater (33) are operated. When the thermal management system (11) is in the second working mode, the first valve (34) is closed, the second valve (52) is closed, and the heater (33) is opened. When the thermal management system (11) is in the third working mode, the first valve (34) is closed, the second valve (52) is closed, and the heater (33) is closed.

26. The control method of claim 25, further comprising: In response to the temperature of the battery (12) being lower than or equal to a second preset temperature and the temperature of the coolant being lower than or equal to a third preset temperature, the thermal management system (11) is switched to the second working mode; In response to the temperature of the battery (12) being lower than or equal to the second preset temperature and the temperature of the coolant being higher than the third preset temperature, the thermal management system (11) is switched to the third working mode; The temperature of the coolant is the coolant temperature of the flow path upstream of the first coolant flow path (31) and the second coolant flow path (32) in parallel communication in the liquid cooling circulation loop (30), and the third preset temperature is higher than the second preset temperature.

27. The control method according to any one of claims 21-26, wherein, According to the working mode of the thermal management system (11), the opening and closing states of the first valve (34), the second valve (52) and the heater (33) are operated. In the fourth working mode of the thermal management system (11), the first valve (34) is opened, the second valve (52) is closed, and the heater (33) is opened. In the fifth working mode of the thermal management system (11), the first valve (34) is opened, the second valve (52) is closed, and the heater (33) is closed.

28. The control method of claim 27, further comprising: in response to the temperature of the energy storage converter (13) being higher than or equal to a fourth preset temperature and the temperature of the coolant being lower than the fifth preset temperature, switching the thermal management system (11) to the fourth working mode; in response to the temperature of the energy storage converter (13) being higher than or equal to a fourth preset temperature, the temperature of the coolant being lower than or equal to the fifth preset temperature and higher than or equal to a sixth preset temperature, switching the thermal management system (11) to the fifth working mode; wherein the temperature of the coolant is the temperature of the coolant in the flow path upstream of the liquid cooling circulation loop (30) in the first coolant flow path (31) and the second coolant flow path (32) in parallel communication, the fifth preset temperature is lower than the sixth preset temperature, and the sixth preset temperature is lower than the fourth preset temperature.

29. The control method according to any one of claims 22-28, wherein, The thermal management system (11) further comprises a refrigerant circulation loop (40) configured to implement a refrigerant circulation and exchange heat with the liquid cooling circulation loop (30); the refrigerant circulation loop (40) has an evaporator (44); the liquid cooling circulation loop (30) has a heat exchange pipeline (35) passing through the evaporator (44) and communicating with the first coolant flow path (31) and the second coolant flow path (32) in parallel communication, and the liquid cooling circulation bypass (50) communicates with the heat exchange pipeline (35) in parallel; wherein the control method further comprises: According to the working mode of the thermal management system (11), the opening and closing state of the refrigerant circulation loop (40) is operated.

30. The control method according to claim 29, wherein According to the working mode of the thermal management system (11), the opening and closing state of the refrigerant circulation loop (40) is operated. In any one of the first working mode, the second working mode, the third working mode, the fourth working mode and the fifth working mode of the thermal management system (11), the refrigeration cycle of the refrigerant circulation loop (40) is closed.

31. The control method according to claim 29 or 30, wherein According to the working mode of the thermal management system (11), the opening and closing state of the first valve (34), the second valve (52) and the heater (33) is operated. In the sixth working mode of the thermal management system (11), the first valve (34) is opened, the second valve (52) is closed, and the heater (33) is closed. According to the working mode of the thermal management system (11), the opening and closing state of the refrigerant circulation loop (40) is operated. In the sixth working mode of the thermal management system (11), the refrigerant circulation loop (40) is opened for refrigeration cycle.

32. The control method according to claim 31, further comprising: in response to the temperature of the coolant being higher than or equal to a seventh predetermined temperature, causing the thermal management system (11) to switch to the sixth operation mode, the temperature of the coolant being a coolant temperature of a flow path of the liquid cooling circuit (30) upstream of the first coolant flow path (31) and the second coolant flow path (32) in the parallel communication.

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