Energy storage device and photovoltaic energy storage system

Abstract

An energy storage device (1000) and a photovoltaic energy storage system. A thermal management system (400) of the energy storage device (1000) comprises a compressor (410), a condenser (420), an expansion valve (430), a dehumidification module (450), and a first evaporator (440), wherein the dehumidification module (450) comprises a second evaporator (4501). A refrigerant outlet (4102) of the compressor (410) is connected to a refrigerant inlet (4201) of the condenser (420), and a refrigerant outlet (4202) of the condenser (420) is connected to a refrigerant inlet (4301) of the expansion valve (430). A refrigerant outlet (4302) of the expansion valve (430) is connected to a refrigerant inlet (45011) of the second evaporator (4501), a refrigerant outlet (45012) of the second evaporator (4501) is connected to a refrigerant inlet (4401) of the first evaporator (440), and a refrigerant outlet (4402) of the first evaporator (440) is connected to a refrigerant inlet (4101) of the compressor (410).

Description

Energy storage device and photoelectric storage system

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of the People's Republic of China on December 29, 2023, with application number 202311868179.8 and invention name "A Kind of Energy Storage Device and Photovoltaic Storage System", the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of energy technology, and in particular to an energy storage device and a photovoltaic storage system. Background Art

[0004] With the continuous development of clean energy, energy storage devices for storing electrical energy have begun to be widely used in various fields. Currently, there is an increasing number of large-scale energy storage devices at the cabinet or container level, which can enhance the energy storage capacity of energy storage devices by configuring more batteries.

[0005] Energy storage devices are usually equipped with a thermal management system to manage the heat of loads such as batteries and power modules inside the device, so that the temperature of the batteries, power modules, etc. can be maintained within a reasonable temperature range to ensure the normal operation of the energy storage device. In addition, the thermal management system can also integrate a dehumidification module to reduce the humidity inside the energy storage device, thereby reducing the risk of corrosion of the load in the energy storage device. Normally, the dehumidification module is connected to the outlet of the compressor. However, due to the limited installation space of the thermal management system in the energy storage device, the size of the dehumidification module cannot be designed too large, which can easily lead to the compressor suction without superheating, resulting in the impact of liquid refrigerant on the compressor, and in severe cases, damage to the compressor.

[0006] Summary of the Invention

[0007] The present application provides an energy storage device and a solar storage system to increase the suction superheat of the compressor, thereby ensuring the safe operation of the compressor and improving the operational reliability of the energy storage device.

[0008] In a first aspect, the present application provides an energy storage device, comprising a thermal management system comprising a compressor, a condenser, an expansion valve, a dehumidification module, and a first evaporator, wherein the dehumidification module includes a second evaporator. The refrigerant outlet of the compressor is connected to the refrigerant inlet of the condenser, which is in turn connected to the refrigerant inlet of the expansion valve. The refrigerant outlet of the expansion valve is connected to the refrigerant inlet of the second evaporator, which is in turn connected to the refrigerant inlet of the first evaporator, which is in turn connected to the refrigerant inlet of the compressor. In the thermal management system for the energy storage device provided herein, the first evaporator and the second evaporator of the dehumidification module are connected in series to the same refrigerant circulation circuit, with the first evaporator located on the refrigerant outlet side of the second evaporator. This allows the refrigerant flowing out of the refrigerant outlet of the second evaporator to be heated by the first evaporator, thereby heating the refrigerant flowing to the refrigerant inlet of the compressor. This helps to increase the suction superheat of the compressor, thereby reducing the risk of liquid refrigerant impacting the compressor, thereby improving the operational safety of the compressor and, in turn, the operational reliability of the energy storage device. Furthermore, the thermal management system for the energy storage device is designed using the solution provided in this application. While ensuring the compressor's suction superheat, it also allows the selection of a slightly larger expansion valve. This effectively reduces the likelihood of expansion valve clogging due to dirtiness and lowers the thermal management system's requirements for refrigerant cleanliness, thereby improving the operational reliability of the thermal management system while reducing its cost. Furthermore, compared to existing thermal management systems that connect the first and second evaporators in parallel, the thermal management system for the energy storage device provided in this application can save at least one expansion valve and one temperature sensor, which helps reduce the cost of the thermal management system.

[0009] In one possible implementation of the present application, the dehumidification module further includes a first fan, with an air outlet of the first fan disposed toward the second evaporator. The first fan is configured to blow air from the energy storage device toward the second evaporator, thereby accelerating the flow of air through the second evaporator and reducing the temperature of the second evaporator, thereby improving the dehumidification effect of the dehumidification module.

[0010] In one possible implementation of the present application, the thermal management system further includes a bypass valve, the refrigerant inlet of the bypass valve being connected to the refrigerant inlet of the second evaporator, and the refrigerant outlet of the bypass valve being connected to the refrigerant outlet of the second evaporator. The bypass valve is then arranged in parallel with the second evaporator. This allows the bypass valve to bypass the second evaporator when there is no dehumidification requirement for the energy storage device. This reduces the pressure drop and flow resistance of the refrigerant flowing through the first evaporator, which helps increase the heat exchange capacity of the first evaporator and thus improves the energy efficiency of the thermal management system.

[0011] In one possible implementation of the present application, the thermal management system further includes a four-way valve, wherein the refrigerant inlet of the first evaporator is connected to the first valve port of the four-way valve, the refrigerant outlet of the second evaporator is connected to the second valve port of the four-way valve, the refrigerant inlet of the second evaporator is connected to the third valve port of the four-way valve, and the refrigerant outlet of the expansion valve is connected to the fourth valve port of the four-way valve. In this way, when the first valve port of the four-way valve is connected to the second valve port of the four-way valve, and the third valve port of the four-way valve is connected to the fourth valve port of the four-way valve, the first evaporator and the second evaporator can be connected in series, thereby realizing the dehumidification function of the dehumidification module. In addition, when the energy storage device does not require dehumidification, the first valve port of the four-way valve is connected to the fourth valve port of the four-way valve, and the second valve port of the four-way valve is connected to the third valve port of the four-way valve. At this time, the second evaporator is bypassed, and the refrigerant enters the compressor through the first evaporator. The pressure drop and flow resistance of the refrigerant flowing through the first evaporator are smaller, which is conducive to increasing the heat exchange capacity of the first evaporator, thereby improving the energy efficiency of the thermal management system.

[0012] In one possible implementation of the present application, the energy storage device further includes a battery module, a power module, and a radiator. The battery module includes a battery and a battery heat exchange plate, and the battery is in contact with the battery heat exchange plate. The power module includes a power circuit and a power circuit heat exchange plate. In addition, the thermal management system further includes a multi-way valve, wherein the coolant outlet of the first evaporator is connected to the first valve port of the multi-way valve, and the coolant inlet of the first evaporator is connected to the second valve port of the multi-way valve. The coolant outlet of the battery heat exchange plate is connected to the third valve port of the multi-way valve, and the coolant inlet of the battery heat exchange plate is connected to the fourth valve port of the multi-way valve. The coolant outlet of the power circuit board is connected to the fifth valve port of the multi-way valve, the coolant inlet of the power circuit board is connected to the coolant outlet of the condenser, and the coolant inlet of the condenser is connected to the sixth valve port of the multi-way valve. The coolant outlet of the radiator is connected to the seventh valve port of the multi-way valve, and the coolant inlet of the radiator is connected to the eighth valve port of the multi-way valve. In this way, by controlling the conduction state between each valve port of the multi-way valve, different connection methods between each coolant passage can be achieved, thereby forming multiple different coolant circulation loops between each coolant passage, providing feasibility conditions for the thermal management system to realize multiple working modes.

[0013] In one possible implementation of this application, the thermal management system further includes an electric heater, the coolant inlet of the electric heater being connected to the fourth valve port of the multi-way valve, and the coolant outlet of the electric heater being connected to the coolant inlet of the battery heat exchange plate. In this way, in low-temperature scenarios, the electric heater can be used to heat the coolant entering the battery heat exchange plate, which in turn transfers the heat to the battery through the battery heat exchange plate, thereby heating the battery.

[0014] In one possible implementation of the present application, the thermal management system further includes a first pump and a second pump. The coolant outlet of the first pump is connected to the coolant inlet of the first evaporator, and the coolant inlet of the first pump is connected to the second valve port of the multi-way valve. Alternatively, the coolant inlet of the first pump is connected to the coolant outlet of the first evaporator, and the coolant outlet of the first pump is connected to the first valve port of the multi-way valve. The coolant outlet of the second pump is connected to the coolant inlet of the condenser, and the coolant inlet of the second pump is connected to the sixth valve port of the multi-way valve. Alternatively, the coolant inlet of the second pump is connected to the coolant outlet of the condenser, and the coolant outlet of the second pump is connected to the coolant inlet of the power circuit heat exchange plate. In this way, the first pump can be arranged in one coolant path of the thermal management system, and the second pump can be arranged in another coolant path of the thermal management system. Moreover, each coolant circulation loop that can be formed in the thermal management system can include at least one of the first pump and the second pump to drive the circulation flow of the coolant in each coolant circulation loop.

[0015] In one possible implementation of the present application, the thermal management system also includes a refilling pot, which can refill at least one coolant circulation loop in the thermal management system. This is helpful in meeting the thermal management system's demand for coolant under different working modes, thereby ensuring that the coolant in each coolant circulation loop is always at an optimal flow rate, thereby improving the reliability and stability of the thermal management system's operation.

[0016] Furthermore, when the coolant outlet of the second pump is connected to the coolant inlet of the condenser, which is in turn connected to the sixth port of the multi-way valve, the refill pot is positioned between the second pump and the sixth port of the multi-way valve. Alternatively, when the coolant inlet of the second pump is connected to the coolant outlet of the condenser, which is in turn connected to the coolant inlet of the power circuit heat exchanger plate, the refill pot is positioned between the power circuit heat exchanger plate and the fifth port of the multi-way valve. This allows the refill pot to contain excess coolant in the coolant circulation loop of the thermal management system due to thermal expansion, thereby reducing the risk of rupture of the connecting pipes within the coolant circulation loop due to excessive pressure.

[0017] In one possible implementation of the present application, the first evaporator is a plate heat exchanger. The second evaporator is a microchannel heat exchanger or a tube-and-fin heat exchanger. This ensures the heat exchange efficiency of the first evaporator and enables the first evaporator to effectively heat the refrigerant flowing out of the refrigerant outlet of the second evaporator, thereby increasing the suction superheat of the compressor.

[0018] In a second aspect, the present application also provides a photovoltaic storage system, comprising a photovoltaic power generation device, a power conversion device, and the energy storage device described in the first aspect, wherein the power device is connected between the photovoltaic power generation device and the energy storage device. The photovoltaic power generation device is configured to store the generated electrical energy in the energy storage device via the power conversion device, thereby utilizing the energy storage device to store electrical energy. By utilizing the aforementioned energy storage device, the operational reliability of the photovoltaic storage system can be effectively improved.

[0019] In a third aspect, the present application further provides a charging network, which may include charging piles and the energy storage device described in the first aspect above, wherein the charging piles are electrically connected to the energy storage device, and the energy storage device is used to provide electrical energy to the charging piles. By applying the above energy storage device, the operational reliability of the charging network can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG1 is a schematic diagram of an application scenario of an energy storage device provided in an embodiment of the present application;

[0021] FIG2 is a schematic diagram of another application scenario of the energy storage device provided in an embodiment of the present application;

[0022] FIG3 is a schematic structural diagram of an energy storage device provided in an embodiment of the present application;

[0023] FIG4 is a schematic structural diagram of a conventional energy storage device provided in an embodiment of the present application;

[0024] FIG5 is a schematic diagram of a system structure of an energy storage device provided in an embodiment of the present application;

[0025] FIG6 is a schematic diagram of another system structure of an energy storage device provided in an embodiment of the present application;

[0026] FIG7 is a schematic diagram of another system structure of an energy storage device provided in an embodiment of the present application;

[0027] FIG8 is a schematic diagram of the system structure of the energy storage device shown in FIG7 in a working mode without dehumidification requirements.

[0028] Description of the Figures: 1000 - Energy Storage Device; 100 - Cabinet; 1001 - Cabinet Door; 200 - Battery Module; 210 - Battery; 220 - Battery Heat Exchange Plate; 2201 - Coolant Inlet of Battery Heat Exchange Plate; 2202 - Coolant Outlet of Battery Heat Exchange Plate; 300 - Power Module; 310 - Power Circuit; 320 - Power Circuit Heat Exchange Plate; 3201 - Coolant Inlet of Power Circuit Heat Exchange Plate; 3202 - Coolant Outlet of Power Circuit Heat Exchange Plate; 400 - Thermal Management System; 410 - Compressor; 4101 - Refrigerant Inlet of Compressor; 4102 - Refrigerant Outlet of Compressor; 420 - Condenser; 4201 - Refrigerant Inlet of Condenser; 4202 - Refrigerant Outlet of Condenser; 4203 - Coolant Inlet of Condenser; 4204 - Coolant outlet of condenser; 430 - Expansion valve; 430a - First expansion valve; 430b - Second expansion valve; 4301 - Refrigerant inlet of expansion valve; 4302 - Refrigerant outlet of expansion valve; 4301a - Refrigerant inlet of first expansion valve; 4301b - Refrigerant inlet of second expansion valve; 440 - First evaporator; 4401 - Refrigerant inlet of first evaporator; 4402 - Refrigerant outlet of first evaporator; 4403 - Coolant inlet of first evaporator; 4404 - Coolant outlet of first evaporator; 450 - Dehumidification module; 4501 - Second evaporator; 45011 - Refrigerant inlet of second evaporator; 45012 - Refrigerant outlet of second evaporator; 4502 - First fan; 460 - Multi-way valve; 470 - Electric heater; 4701 - Coolant inlet of electric heater; 4702 - Coolant outlet of electric heater; 480 - First pump; 4801 - Coolant inlet of first pump; 4802 - Coolant outlet of first pump; 490 - Second pump; 4901 - Coolant inlet of second pump; 4902 - Coolant outlet of second pump; 4100 - Refill pot; 4110 - Bypass valve; 41101 - Refrigerant inlet of bypass valve; 41102 - Refrigerant outlet of bypass valve; 4120 - Four-way valve; 500 - Radiator module; 510 - Radiator; 5101 - Coolant inlet of radiator; 5102 - Coolant outlet of radiator; 520 - Second fan; T1, T2 - Temperature sensors; A - First coolant passage; B - Second coolant passage; C - Third coolant passage; D - Fourth coolant passage; v1 - the first valve port of the multi-way valve; v2 - the second valve port of the multi-way valve; v3 - the third valve port of the multi-way valve; v4 - the fourth valve port of the multi-way valve; v5 - the fifth valve port of the multi-way valve; v6 - the sixth valve port of the multi-way valve; v7 - the seventh valve port of the multi-way valve; v8 - the eighth valve port of the multi-way valve; a1 - the first valve port of the four-way valve; a2 - the second valve port of the four-way valve; a3 - the third valve port of the four-way valve; a4 - the fourth valve port of the four-way valve. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present application clearer, the embodiments of the present application will be further described in detail with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as being limited to the embodiments set forth herein. The same reference numerals in the figures represent the same or similar structures, and thus their repeated description will be omitted. The words expressing position and direction described in the embodiments of the present application are all explained using the accompanying drawings as examples, but changes may be made as needed, and the changes made are all included in the scope of protection of the present application. The drawings in the embodiments of the present application are only used to illustrate the relative position relationship and do not represent the true proportion.

[0030] It should be noted that the following description sets forth specific details to facilitate understanding of the present application. However, the embodiments of the present application can be implemented in a variety of other ways than those described herein, and those skilled in the art can make similar generalizations without violating the connotations of the embodiments of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0031] Energy storage devices are devices that store electrical energy in a medium and release it to generate electricity when needed. They can be used in five industrial and commercial energy storage scenarios: small-scale commercial and industrial (e.g., small factories), medium-scale commercial and industrial (e.g., large-scale commercial and industrial), photovoltaic storage and charging stations, and small and medium-sized microgrids (e.g., islands). They can also be used in three power station scenarios: wind-solar energy storage stations, grid energy storage stations, and large microgrids.

[0032] As shown in Figure 1, Figure 1 is a schematic diagram of an application scenario of the energy storage device provided in an embodiment of the present application, which is illustrated using a photovoltaic storage system as an example. The photovoltaic storage system may include a power conversion device, a power generation device, and an energy storage device. The power conversion device is connected between the power generation device and the energy storage device, and the power generation device is used to store the generated electrical energy in the energy storage device through the power conversion device.

[0033] In some embodiments, the power generation device may be a photovoltaic power generation device, which can be used to convert light energy into direct current electrical energy.

[0034] In some embodiments, the power generation device may be a wind power generation device, which can be used to convert wind energy into direct current electrical energy.

[0035] As shown in Figure 2, Figure 2 is a schematic diagram of another application scenario of the energy storage device provided in an embodiment of the present application. This application scenario is described using a charging network as an example. The charging network includes a charging pile and an energy storage device. The charging pile and the energy storage device are electrically connected via a cable, and the energy storage device can provide its stored electrical energy to the charging pile. The charging pile has a connector that can be connected to a powered device (such as a vehicle) to charge the powered device.

[0036] In addition, in an embodiment of the present application, the energy storage device can be divided into a cabinet-level energy storage device and a container-level energy storage device according to the different requirements of the application scenario for power consumption. Referring to Figure 3, Figure 3 is a structural schematic diagram of an energy storage device 1000 provided in an embodiment of the present application. This embodiment is described by taking a cabinet-level energy storage device as an example. The energy storage device 1000 may include a cabinet 100, a battery module 200, and a power module 300. Both the battery module 200 and the power module 300 can be accommodated in the cabinet 100. The battery module 200 is the basic unit for the energy storage device 1000 to realize the storage and release of electrical energy. The power module 300 can be used to control the charging and discharging process of the battery. For example, the power module 300 may include a power conversion system (PCS) or a direct current converter (DCDC). Among them, PCS can be used to convert AC power into DC power and then provide it to the battery, or convert DC power from the battery into AC power and then output it. DCDC can be used to boost the battery module 200 to ensure that the total voltage of the battery module 200 is not lower than the rated voltage, thereby improving the stability of the operation of the battery module 200.

[0037] In the above-mentioned energy storage device, the battery module 200 and the power module 300 are the main heat loads in the energy storage device 1000. The temperature of the battery module 200 and the power module 300 is an important condition that affects whether the energy storage device 1000 can operate normally. For the battery module 200, in a high temperature environment, such as summer or the transition season between spring and autumn, the battery module 200 will generate a lot of heat during the charging and discharging process. In this case, it is often necessary to cool the battery module 200 to ensure the normal operation of the battery module 200; while in the winter when the temperature is relatively low, the battery module 200 may cause charging and discharging failures due to low temperature. Therefore, in this case, it is necessary to heat the battery module 200 to ensure the normal operation of the battery module 200. For the power module 300, since the power module 300 always generates a lot of heat during operation, it is usually necessary to cool the power module 300 in a timely manner under various environmental conditions to ensure its normal operation.

[0038] In addition, in some cases, such as in low temperature and high humidity environments, battery modules and power modules also need to be dehumidified to reduce the risk of corrosion damage to the battery modules and power modules.

[0039] Based on this, the current energy storage device 1000 is also provided with a thermal management system 400. As shown in FIG3 , currently, in order to reasonably utilize the space inside the cabinet 100 of the energy storage device 1000, the thermal management system 400 can be provided on the cabinet door 1001 of the cabinet 100.

[0040] The thermal management system 400 can simultaneously meet the temperature and humidity management requirements of the battery module 200 and the power module 300. When setting it specifically, please refer to Figure 4, which is a structural schematic diagram of a traditional energy storage device provided in an embodiment of the present application, which shows the setting method of the thermal management system in the energy storage device. Among them, the thermal management system includes a compressor 410, a condenser 420, a first expansion valve 430a and a first evaporator 440, and the compressor 410, condenser 420, first expansion valve 430a and first evaporator 440 are connected in sequence to form a refrigerant circulation loop.

[0041] In addition, in the energy storage device shown in Figure 4, the thermal management system also includes a dehumidification module 450 and a second expansion valve 430b. The dehumidification module 450 includes a second evaporator 4501. The second evaporator 4501 is connected in series with the second expansion valve 430b, and the refrigerant outlet 45012 of the second evaporator and the refrigerant outlet 4402 of the first evaporator are both connected to the refrigerant inlet 4101 of the compressor, and the refrigerant inlet 4301b of the second expansion valve and the refrigerant inlet 4301a of the first expansion valve are both connected to the refrigerant outlet 4202 of the condenser, thereby realizing the parallel connection of the second evaporator 4501 and the first evaporator 440.

[0042] Due to the limited space required for the thermal management system within the energy storage device, the second evaporator 4501 in the dehumidification module 450 cannot be oversized. Furthermore, in low-temperature, high-humidity environments, the thermal management system's load is relatively low, for example, less than 700W. This results in a low heat exchange capacity for the second evaporator 4501, which can easily lead to low or no suction superheat in the compressor 410. This can cause liquid refrigerant to impact the compressor 410, potentially damaging it.

[0043] In view of this, the energy storage device provided in the embodiment of the present application adjusts the location of the dehumidification module in the thermal management system so that when the energy storage device requires dehumidification, the refrigerant flowing out of the refrigerant liquid outlet of the dehumidification module can be heated. This helps to increase the suction superheat of the compressor, thereby improving the operating safety of the compressor and, in turn, the operating reliability of the energy storage device. To make the objectives, technical solutions, and advantages of this application more clear, this application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0044] Referring to Figure 5 , which is a schematic diagram of a system structure of an energy storage device provided in an embodiment of the present application, the thermal management system in the energy storage device includes a compressor 410, a condenser 420, an expansion valve 430, a dehumidification module 450, and a first evaporator 440. The dehumidification module 450 includes a second evaporator 4501, which can be a microchannel heat exchanger or a tube-and-fin heat exchanger, while the first evaporator 440 can be a plate heat exchanger.

[0045] As shown in FIG5 , the refrigerant outlet 4102 of the compressor is connected to the refrigerant inlet 4201 of the condenser, which is connected to the refrigerant inlet 4301 of the expansion valve, which is connected to the refrigerant inlet 45011 of the second evaporator, which is connected to the refrigerant outlet 45012 of the second evaporator and the refrigerant inlet 4401 of the first evaporator. The refrigerant outlet 4402 of the first evaporator is connected to the refrigerant inlet 4101 of the compressor. Thus, the compressor 410, condenser 420, expansion valve 430, first evaporator 440, and second evaporator 4501 are sequentially connected to form a refrigerant circulation loop. A refrigerant can circulate in the refrigerant circulation loop, where the refrigerant may be, but is not limited to, Freon or liquid ammonia compounds.

[0046] In the embodiment of the present application, when the refrigerant flows through the second evaporator 4501, the temperature of the second evaporator 4501 is relatively low. Therefore, when the air humidity in the energy storage device is high and the temperature of the second evaporator 4501 is lower than the dew point temperature of the air, the water vapor in the air condenses into water droplets, which are then discharged through the drainage pipe of the energy storage device to reduce the humidity in the energy storage device.

[0047] It is understandable that, since the temperature of the second evaporator 4501 is relatively low during the circulation of the refrigerant in the above-mentioned refrigerant circulation loop, the second evaporator 4501 can also reduce the temperature of the air in the energy storage device. In addition, the dehumidification module 450 also includes a first fan 4502, the air outlet of the first fan 4502 is arranged toward the second evaporator 4501, and the first fan 4502 is used to blow the air in the energy storage device toward the second evaporator 4501, thereby accelerating the circulation speed of the air flowing through the second evaporator 4501 to reduce the temperature of the second evaporator 4501, which is conducive to improving the dehumidification effect of the dehumidification module 450.

[0048] In the thermal management system of the energy storage device provided in the present application, the first evaporator 440 and the second evaporator 4501 of the dehumidification module 450 are connected in series to the same refrigerant circulation loop, and the first evaporator 440 is located on the side of the refrigerant outlet 45012 of the second evaporator. In this way, the refrigerant flowing out of the refrigerant outlet 45012 of the second evaporator can be heated by the first evaporator 440, thereby achieving the heating of the refrigerant flowing to the refrigerant inlet 4101 of the compressor, which is beneficial to improving the suction superheat of the compressor 410, so as to reduce the risk of liquid refrigerant impacting the compressor 410, thereby improving the operating safety of the compressor 410, and further improving the operating reliability of the energy storage device.

[0049] In addition, the thermal management system of the energy storage device is designed using the solution provided in this application. While ensuring the suction superheat of the compressor 410, a slightly larger expansion valve 430 can also be selected. This can effectively reduce the possibility of the expansion valve 430 being dirty and blocked, and reduce the thermal management system's requirements for the cleanliness of the refrigerant, thereby improving the operational reliability of the thermal management system while reducing the cost of the thermal management system. In addition, since the thermal management system in the energy storage setting provided in this application can include only one expansion valve 430 and one temperature sensor T1, while the thermal management system of the existing energy storage device shown in Figure 4 includes a first expansion valve 430a, a second expansion valve 430b, a temperature sensor T1, and a temperature sensor T2, compared with the solution in which the first evaporator 440 and the second evaporator 4501 are connected in parallel in the existing thermal management system, the thermal management system of the energy storage device provided in this application can save at least one expansion valve and one temperature sensor, which is conducive to reducing the cost of the thermal management system.

[0050] In the present application, the specific type of the expansion valve 430 is not limited. An exemplary type of the expansion valve 430 may be an electronic expansion valve to improve the regulation accuracy of the expansion valve 430 .

[0051] Continuing with FIG. 5 , in the energy storage device provided herein, the thermal management system further includes a multi-way valve 460 . The coolant outlet 4404 of the first evaporator is connected to the first valve port v1 of the multi-way valve, and the coolant inlet 4403 of the first evaporator is connected to the second valve port v2 of the multi-way valve. This connects the coolant flow path of the first evaporator 440 to the multi-way valve 460 , thereby connecting the first evaporator 440 and the multi-way valve 460 via a coolant pipe to form a first coolant passage A. In the present application, the coolant passage can be used for the circulation of a coolant, wherein the coolant can be, but is not limited to, water or ethylene glycol.

[0052] It is worth mentioning that in the embodiment of the present application, the connection between the coolant outlet and coolant inlet of each component and the multi-way valve 460 can be a direct connection or an indirect connection. A direct connection means that only a coolant pipe is provided between the coolant outlet and coolant inlet and the corresponding valve ports of the multi-way valve 460, while an indirect connection means that other components are also connected in series between the coolant outlet and coolant inlet and the corresponding valve ports of the multi-way valve 460 via a coolant pipe.

[0053] The energy storage device provided in this embodiment of the application also includes a battery module 200, which includes a battery 210 and a battery heat exchange plate 220. The battery 210 is in contact with the battery heat exchange plate 220. The coolant outlet 2202 of the battery heat exchange plate is connected to the third valve port v3 of the multi-way valve, and the coolant inlet 2201 of the battery heat exchange plate is connected to the fourth valve port v4 of the multi-way valve. Thus, the battery heat exchange plate 220 and the multi-way valve 260 are connected through the coolant pipe to form a second coolant passage B.

[0054] It is worth mentioning that in the energy storage device provided in the embodiment of the present application, the battery heat exchange plate 220 can be a cold plate or other types of heat exchangers such as an immersion heat exchanger, as long as it can be used for the circulation of coolant and can be used to achieve heat exchange with the battery 210.

[0055] As shown in Figure 5, the energy storage device also includes a power module 300, which includes a power circuit 310 and a power circuit heat exchange plate 320. The power circuit 310 and the power circuit heat exchange plate 320 are in contact with each other. The coolant outlet 3202 of the power circuit heat exchange plate is connected to the fifth valve port v5 of the multi-way valve. The coolant inlet 3201 of the power circuit heat exchange plate is connected to the coolant outlet 4204 of the condenser. The coolant inlet 4203 of the condenser is connected to the sixth valve port v6 of the multi-way valve. As a result, the condenser 420, the power circuit heat exchange plate 320, and the multi-way valve 460 are connected via the coolant pipeline to form a third coolant passage C.

[0056] It is worth noting that in the energy storage device provided in the embodiments of the present application, the power circuit heat exchange plate 320 can be a cold plate or another type of heat exchanger, such as an immersion heat exchanger. Furthermore, when both the battery heat exchange plate 220 and the power circuit heat exchange plate 320 are immersion heat exchangers, they can also be integrated, i.e., the battery 210 and the power circuit 310 can be immersed in the same immersion heat exchanger.

[0057] 5 , the energy storage device provided in the present application may further include a radiator module 500, the radiator module 500 including a radiator 510, the coolant outlet 5102 of the radiator being connected to the seventh valve port v7 of the multi-way valve, and the coolant inlet 5101 of the radiator being connected to the eighth valve port v8 of the multi-way valve, so that the radiator 510 is connected to the multi-way valve 460 through a coolant pipe to form a fourth coolant passage D.

[0058] In addition, the radiator module 500 may further include a second fan 520 , which is disposed close to the radiator 510 . The second fan 520 may be used to accelerate the flow rate of air passing through the radiator 510 , thereby improving the heat dissipation performance of the radiator 510 .

[0059] The present application does not limit the specific configuration of the multi-way valve 460. For example, it may include an eight-way valve to provide eight valve ports for connecting the four coolant passages. Alternatively, the multi-way valve 460 may include two four-way valves to provide eight valve ports by connecting the two four-way valves. Of course, the multi-way valve 460 may also adopt other possible configurations, which will not be described here.

[0060] In the energy storage device provided in the embodiment of the present application, the four coolant passages are connected via the eight valve ports of a multi-way valve 460. This allows for different connection modes between the four coolant passages by controlling the conduction states between the various valve ports of the multi-way valve 460. This, in turn, allows for the formation of multiple different coolant circulation loops between the four coolant passages, thereby providing feasibility for the thermal management system to implement multiple operating modes. Furthermore, using the multi-way valve 460 to connect the four coolant passages not only improves the integration of the thermal management system but also simplifies the thermal management system's connecting piping, thereby contributing to improved energy efficiency of the thermal management system.

[0061] In specific applications, different coolant circulation loops can be formed by controlling the conduction states between the various ports of multi-way valve 460 to ensure that different coolant paths are connected, depending on the thermal management requirements of the energy storage device in different scenarios. The following describes the coolant circulation loops that can be formed by the thermal management system for several possible scenarios.

[0062] In the first scenario, the first valve port v1 of the multi-way valve is connected to the fourth valve port v4, the second valve port v2 is connected to the third valve port v3, the fifth valve port v5 is connected to the eighth valve port v8, and the sixth valve port v6 is connected to the seventh valve port v7. In this scenario, the first coolant passage A is connected to the second coolant passage B to form a first coolant circulation loop, and the third coolant passage C is connected to the fourth coolant passage D to form a second coolant circulation loop. As shown in Figure 5, the first coolant circulation loop includes the coolant flow path of the first evaporator 440 and the battery heat exchange plate 220. In this scenario, the coolant circulating in the first coolant circulation loop can transfer heat generated by the battery 210 to the first evaporator 440. After cooling in the first evaporator 440, the coolant further flows to the battery heat exchange plate 220 for heat exchange. In addition, the second coolant circulation loop includes the coolant flow path of the condenser 420, the power circuit heat exchange plate 320, and the radiator 510. This allows heat to be dissipated from both the condenser 420 and the power circuit heat exchange plate via the radiator 510. Thus, the first scenario can be a high-temperature scenario, such as in summer. In this case, the compressor 410 needs to be turned on, and the refrigerant circulates in the refrigerant circulation loop to cool the battery 210.

[0063] In the second scenario, the first valve port v1 of the multi-way valve is connected to the fourth valve port v4, the second valve port v2 of the multi-way valve is connected to the seventh valve port v7, the third valve port v3 of the multi-way valve is connected to the sixth valve port v6, and the fifth valve port v5 of the multi-way valve is connected to the eighth valve port v8. In this scenario, the first coolant passage A, the second coolant passage B, the third coolant passage C, and the fourth coolant passage D are connected to form a third coolant circulation loop. As the coolant circulates in the third coolant circulation loop, the radiator 510 can be used to cool the battery heat exchange plate 220 and the power circuit heat exchange plate 320, thereby dissipating heat from the battery 210 and the power circuit 310. This indicates that the second scenario may be a more suitable ambient temperature scenario, such as in spring or autumn. In this scenario, the compressor 410 can be turned off or operated in a low-load mode.

[0064] In the third scenario, the first valve port v1 of the multi-way valve is connected to the eighth valve port v8, the second valve port v2 of the multi-way valve is connected to the seventh valve port v7, the third valve port v3 of the multi-way valve is connected to the sixth valve port v6, and the fourth valve port v4 of the multi-way valve is connected to the fifth valve port v5. In this scenario, the first coolant passage A is connected to the fourth coolant passage D to form a fourth coolant circulation loop, and the second coolant passage B is connected to the third coolant passage C to form a fifth coolant circulation loop. As shown in Figure 5, the fourth coolant circulation loop includes the coolant flow path of the first evaporator 440 and the radiator 510. In this scenario, the coolant is cooled by the first evaporator 440 and then enters the radiator 510. In the radiator 510, the coolant is heated by heat exchange with the air on the surface of the radiator 510 and then enters the first evaporator 440 again. In addition, the fifth coolant circulation loop includes the coolant flow path of the condenser 420, the battery heat exchange plate 220, and the power circuit heat exchange plate 320. The coolant exchanges heat with the condenser 420 and heats up before entering the power circuit heat exchange plate 320. Since the power circuit 310 generates a large amount of heat during operation, this heat is also transferred to the coolant through the power circuit heat exchange plate 320 to dissipate heat from the power circuit 310. The coolant then enters the battery heat exchange plate 220, where it exchanges heat with the battery 210 and cools down before returning to the coolant flow path of the condenser 420, completing a cycle. In this scenario, the power circuit 310 dissipates heat and cools down by transferring heat to the coolant, while the battery 210 heats up by absorbing the heat from the coolant. Therefore, the fifth coolant circulation loop can also, to a certain extent, utilize the waste heat generated by the power circuit 310 to heat the battery, thereby rationally utilizing the waste heat generated by the power circuit 310 and achieving efficient heat utilization.

[0065] Continuing with FIG. 5 , in this embodiment of the present application, the thermal management system further includes an electric heater 470, which may be disposed, for example, in the second coolant passage B. Specifically, the electric heater's coolant inlet 4701 is connected to the fourth valve port v4 of the multi-way valve, and the electric heater's coolant outlet 4702 is connected to the coolant inlet 2201 of the battery heat exchange plate. Thus, in low-temperature scenarios, the electric heater 470 can be used to heat the coolant entering the battery heat exchange plate 220, thereby transferring heat to the battery 210 through the battery heat exchange plate 220 to heat the battery 210.

[0066] It is understandable that the electric heater 470 may also be provided in other coolant passages, as long as the electric heater 470 can heat the coolant entering the battery heat exchange plate 220 .

[0067] In an embodiment of the present application, the thermal management system may further include a first pump 480 and a second pump 490, the first pump 480 being arranged in one of the above-mentioned four coolant passages of the thermal management system, and the second pump 490 being arranged in another coolant passage of the above-mentioned four coolant passages of the thermal management system, and in the above-mentioned five coolant circulation loops, each coolant circulation loop includes at least one of the first pump 480 and the second pump 490 to drive the circulation flow of the coolant in each coolant circulation loop.

[0068] Based on the above considerations, in one possible embodiment, as shown in Figure 5 , the first pump 480 is disposed in the first coolant passage A. The first pump 480 is then connected in series with the coolant flow path of the first evaporator 440. Specifically, the first pump's coolant outlet 4802 is connected to the first evaporator's coolant inlet 4403, and the first pump's coolant inlet 4801 is connected to the second valve port v2 of the multi-way valve. Thus, the first pump 480 is disposed between the first evaporator's coolant inlet 4403 and the second valve port v2 of the multi-way valve. Alternatively, the first pump 480 can be disposed between the first evaporator's coolant outlet 4404 and the first valve port v1 of the multi-way valve. Specifically, the first pump's coolant inlet 4801 is connected to the first evaporator's coolant outlet 4404, and the first pump's coolant outlet 4802 is connected to the first valve port v1 of the multi-way valve. In this manner, the first pump 480 is also disposed in the first, third, and fourth coolant circulation loops.

[0069] Continuing with Figure 5 , if the second pump 490 is disposed in the third coolant passage C, the second pump 490 is connected in series with the coolant flow path of the condenser 420 and the power circuit heat exchange plate 320. Specifically, the coolant outlet 4902 of the second pump is connected to the coolant inlet 4203 of the condenser, and the coolant inlet 4901 of the second pump is connected to the sixth valve port v6 of the multi-way valve. In this case, the second pump 490 is disposed between the coolant inlet 4203 of the condenser and the sixth valve port v6 of the multi-way valve. Alternatively, the coolant inlet 4901 of the second pump is connected to the coolant outlet 4204 of the condenser, and the coolant outlet 4902 of the second pump is connected to the coolant inlet 3201 of the power circuit heat exchange plate. In this case, the second pump 490 is disposed between the condenser 420 and the power circuit heat exchange plate 320. Alternatively, the second pump 490 can be disposed elsewhere in the third coolant passage C. In this way, the second pump 490 is also provided in the second coolant circulation loop, the third coolant circulation loop, and the fifth coolant circulation loop.

[0070] The above is only an exemplary introduction to the setting positions of the first pump 480 and the second pump 490 in the thermal management system. In other possible embodiments of the present application, the specific setting positions of the first pump 480 and the second pump 490 can also be adjusted. They are not introduced one by one here, but they should all be understood to fall within the scope of protection of this application.

[0071] Continuing with reference to Figure 5, in an embodiment of the present application, the thermal management system also includes a fluid replenishing pot 4100, which can be connected to one of the four coolant passages mentioned above. Since any one of the four coolant passages is directly connected to the same coolant circulation loop with other coolant passages, or is indirectly connected to other coolant passages through another coolant passage, the fluid replenishing pot 4100 can replenish fluid for any one of the five coolant circulation loops mentioned above to meet the thermal management system's demand for coolant in different working modes, thereby ensuring that the coolant in each coolant circulation loop is always at an optimal flow rate to improve the reliability and stability of the thermal management system's operation.

[0072] In one possible embodiment of the present application, the fluid rehydration pot 4100 is connected to a coolant passage having a pump, and the fluid rehydration pot 4100 is disposed adjacent to the pump so that the pump can readily draw fluid from the fluid rehydration pot 4100. For example, in the embodiment shown in FIG5 , where the first pump 480 is connected to the first coolant passage A and the second pump 490 is connected to the third coolant passage C, the fluid rehydration pot 4100 can be connected to the third coolant passage C. Since the heat generated by the power circuit 310 is relatively large, after the power circuit heat exchange plate 320 is connected to the third coolant passage C, the coolant will initially heat up after flowing through the power circuit heat exchange plate 320, and then the temperature will rise again after passing through the condenser 420. Under the action of high temperature, the coolant in the third coolant passage C will expand to a certain extent. By connecting the rehydration pot 4100 to the third coolant passage C, the rehydration pot 4100 can be used to temporarily accommodate this part of the excess coolant after expansion, so as to reduce the risk of the connecting pipe in the third coolant passage C rupture due to excessive pressure.

[0073] In addition, in the third coolant passage C, when the second pump 490 is connected between the coolant inlet 4203 of the condenser and the sixth valve port v6 of the multi-way valve, the fluid replenishment pot 4100 can be arranged between the second pump 490 and the sixth valve port v6 of the multi-way valve, so that the fluid replenishment pot 4100 is arranged closer to the sixth valve port v6 of the multi-way valve than the second pump 490, or, when the second pump 490 is connected between the coolant outlet 4204 of the condenser and the fifth valve port v5 of the multi-way valve, the fluid replenishment pot 4100 can be arranged closer to the fifth valve port v5 of the multi-way valve than the coolant outlet 4204 of the condenser. In this way, the fluid replenishment pot 4100 can not only realize the aforementioned fluid replenishment function, but also stabilize the pressure inside the multi-way valve 460, thereby improving the working stability of the multi-way valve 460 under different connection states.

[0074] As can be understood from the above description of the energy storage device provided in this application, the first evaporator 440 and the dehumidification module 450 of the thermal management system of the energy storage device can operate independently or in a coupled manner to achieve temperature and / or humidity management of the energy storage device. For example, in the second scenario, that is, in spring or autumn when the ambient temperature is relatively suitable but the air humidity is relatively high, the first fan 4502 of the dehumidification module 450 can be activated to achieve the dehumidification function of the dehumidification module 450. In addition, compressor 410 can be operated in a low-load mode, and at least one of first water pump 480 and second water pump 490 can be activated simultaneously, so that coolant can circulate through a third coolant circulation loop, which includes the coolant flow path of first evaporator 440, battery heat exchange plate 220, coolant flow path of condenser 420, power circuit heat exchange plate 320, and radiator 510. Thus, heat generated by battery 210 and power circuit 310 can be transferred to first evaporator 440 through heat exchange between the coolant and battery heat exchange plate 220 and power heat exchange plate 320, and heat exchanged with refrigerant flowing through first evaporator 440. Because first evaporator 440 is located at refrigerant outlet 45012 of second evaporator, the refrigerant that has exchanged heat with first evaporator 440 can heat the refrigerant flowing out of refrigerant outlet 45012 of second evaporator, thereby increasing the suction superheat of compressor 410 and ensuring the safe operation of compressor 410.

[0075] It is understood that in the above scenario, the first evaporator 440 primarily heats the refrigerant flowing out of the refrigerant outlet 45012 of the second evaporator. Furthermore, when the suction superheat requirement of the compressor 410 is high, the electric heater 470 can be turned on to heat the coolant to further increase the superheat of the refrigerant outlet 45012 of the second evaporator, thereby ensuring that the suction superheat of the compressor 410 meets the requirement and enables safe operation of the compressor 410.

[0076] In addition, in the first scenario, that is, the scenario where the battery 210 has a cooling demand, the second fan 520 of the dehumidification module 450 can be turned off, and the first water pump 480 and the second water pump 490 can be started at the same time, so that the coolant can circulate in the first coolant circulation loop including the coolant flow channel of the first evaporator 440 and the battery heat exchange plate 220, so that the coolant transfers the heat generated by the battery 210 to the first evaporator 440, and the coolant after cooling through the first evaporator 440 further flows to the battery heat exchange plate 220 for heat exchange, thereby achieving cooling of the battery 210.

[0077] Referring to Figure 6, Figure 6 is another system structure diagram of the energy storage device provided in an embodiment of the present application. Unlike the energy storage device shown in Figure 5 above, in the energy storage device shown in Figure 6, the thermal management system also includes a bypass valve 4110, the refrigerant inlet 41101 of the bypass valve is connected to the refrigerant inlet 45011 of the second evaporator, and the refrigerant outlet 41102 of the bypass valve is connected to the refrigerant outlet 45012 of the second evaporator, and the bypass valve 4110 is arranged in parallel with the second evaporator 4501. In this way, when there is no dehumidification requirement for the energy storage device, the second evaporator 4501 can be bypassed by opening the bypass valve 4110, so that the pressure drop of the refrigerant flowing through the first evaporator 440 is small and the flow resistance is small, which is conducive to improving the heat exchange capacity of the first evaporator 440, thereby improving the energy efficiency of the thermal management system.

[0078] It is worth mentioning that in the energy storage device shown in Figure 6, the bypass valve 4110 can be exemplarily a solenoid valve, which is not limited in this application. In addition, the other structures of the energy storage device shown in Figure 6 can be set with reference to the energy storage device shown in Figure 5 above, and will not be described in detail here.

[0079] Referring to Figure 7 , which is a schematic diagram of another system structure of an energy storage device provided in an embodiment of the present application, unlike the energy storage device shown in Figure 5 , the energy storage device shown in Figure 7 further includes a thermal management system comprising a four-way valve 4120, wherein the refrigerant inlet 4401 of the first evaporator is connected to the first valve port a1 of the four-way valve, the refrigerant outlet 45012 of the second evaporator is connected to the second valve port a2 of the four-way valve, the refrigerant inlet 45011 of the second evaporator is connected to the third valve port a3 of the four-way valve, and the refrigerant outlet 4302 of the expansion valve is connected to the fourth valve port a4 of the four-way valve.

[0080] In the energy storage device shown in FIG7 , the connection mode between the first evaporator 440 and the second evaporator 4501 can be switched by controlling the conduction state between the various valve ports of the four-way valve 4120. For example, referring to FIG7 , in the second scenario, i.e., in spring or autumn when the ambient temperature is relatively suitable but the air humidity is relatively high, the first valve port a1 of the four-way valve can be controlled to conduct with the second valve port a2 of the four-way valve, and the third valve port a3 of the four-way valve can be controlled to conduct with the fourth valve port a4 of the four-way valve, thereby achieving the series connection between the first evaporator 440 and the second evaporator 4501.

[0081] In addition, when the energy storage device has no dehumidification requirement, refer to Figure 8, which is a schematic diagram of the system structure in the energy storage device without dehumidification requirement working mode shown in Figure 7. Among them, the first valve port a1 of the four-way valve is connected to the fourth valve port a4 of the four-way valve, and the second valve port a2 of the four-way valve is connected to the third valve port a3 of the four-way valve. At this time, the second evaporator 4501 is bypassed, and the refrigerant enters the compressor 410 through the first evaporator 440. The pressure drop of the refrigerant flowing through the first evaporator 440 is smaller and the flow resistance is smaller, which is conducive to improving the heat exchange capacity of the first evaporator 440, thereby improving the energy efficiency of the thermal management system.

[0082] In summary, in an embodiment of the present application, the first evaporator 440 and the second evaporator 4501 of the dehumidification module 450 are connected in series to the same refrigerant circulation loop, and the first evaporator 440 is located on the side of the refrigerant outlet 45012 of the second evaporator. In this way, the refrigerant flowing out of the refrigerant outlet 45012 of the second evaporator can be heated by the first evaporator 440, thereby achieving the heating of the refrigerant flowing to the refrigerant inlet 4101 of the compressor, which is beneficial to improving the suction superheat of the compressor 410, so as to reduce the risk of liquid refrigerant impacting the compressor 410, thereby improving the operating safety of the compressor 410, and then improving the operating reliability of the energy storage device.

[0083] In addition, the thermal management system of the energy storage device is designed using the solution provided in this application. While ensuring the suction superheat of the compressor 410, it can also select a slightly larger expansion valve 430. This can effectively reduce the possibility of expansion valve 430 becoming dirty and clogged, and reduce the thermal management system's requirements for refrigerant cleanliness, thereby improving the operational reliability of the thermal management system while reducing the cost of the thermal management system. In addition, compared with the solution of connecting the first evaporator 440 and the second evaporator 4501 in parallel in the existing thermal management system, the thermal management system of the energy storage device provided in this application can save at least one expansion valve and one temperature sensor, which is conducive to reducing the cost of the thermal management system.

[0084] It is understood that, based on the energy storage device provided in the above-mentioned embodiment of the present application, some possible adjustments can be made to the structure of the thermal management system of the energy storage device. For example, the relative positions of the first evaporator 440 and the second evaporator 4501 can be interchanged, that is, the refrigerant inlet 45011 of the second evaporator is connected to the refrigerant outlet 4402 of the first evaporator, and the refrigerant outlet 45012 of the second evaporator is connected to the refrigerant inlet 4401 of the first evaporator. In this case, an additional heat source can be added to heat the refrigerant flowing out of the refrigerant outlet 45012 of the second evaporator, thereby increasing the suction superheat of the compressor 410. Of course, on this basis, other possible variations can be made to the energy storage device provided in the embodiment of the present application. They will not be introduced one by one here, but they should all be understood to fall within the scope of protection of the present application.

[0085] The above are only specific embodiments of the present application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. An energy storage device, characterized in that, Comprising a thermal management system, the thermal management system includes a compressor, a condenser, an expansion valve, a dehumidification module, and a first evaporator, the dehumidification module includes a second evaporator, wherein: The refrigerant outlet of the compressor is connected to the refrigerant inlet of the condenser, and the refrigerant outlet of the condenser is connected to the refrigerant inlet of the expansion valve; the refrigerant outlet of the expansion valve is connected to the refrigerant inlet of the second evaporator, and the refrigerant outlet of the second evaporator is connected to the refrigerant inlet of the first evaporator; the refrigerant outlet of the first evaporator is connected to the refrigerant inlet of the compressor.

2. The energy storage device according to claim 1, characterized in that, The dehumidification module further includes a first fan, and the air outlet of the first fan is arranged facing the second evaporator.

3. The energy storage device according to claim 1 or 2, characterized in that The thermal management system further includes a bypass valve, the refrigerant inlet of the bypass valve is connected to the refrigerant inlet of the second evaporator, and the refrigerant outlet of the bypass valve is connected to the refrigerant outlet of the second evaporator.

4. The energy storage device according to claim 1 or 2, characterized in that The thermal management system further includes a four-way valve, the refrigerant inlet of the first evaporator is connected to the first valve port of the four-way valve, the refrigerant outlet of the second evaporator is connected to the second valve port of the four-way valve, the refrigerant inlet of the second evaporator is connected to the third valve port of the four-way valve, and the refrigerant outlet of the expansion valve is connected to the fourth valve port of the four-way valve.

5. The energy storage device according to any one of claims 1 to 4, characterized in that The energy storage device further includes a battery module, a power module, and a radiator. The battery module includes a battery and a battery heat exchange plate, and the battery is in contact with the battery heat exchange plate; the power module includes a power circuit and a power circuit heat exchange plate; The thermal management system further includes a multi-way valve. The coolant outlet of the first evaporator is connected to the first valve port of the multi-way valve, and the coolant inlet of the first evaporator is connected to the second valve port of the multi-way valve; the coolant outlet of the battery heat exchange plate is connected to the third valve port of the multi-way valve, and the coolant inlet of the battery heat exchange plate is connected to the fourth valve port of the multi-way valve; the coolant outlet of the power circuit board is connected to the fifth valve port of the multi-way valve, the coolant inlet of the power circuit board is connected to the coolant outlet of the condenser, and the coolant inlet of the condenser is connected to the sixth valve port of the multi-way valve; the coolant outlet of the radiator is connected to the seventh valve port of the multi-way valve, and the coolant inlet of the radiator is connected to the eighth valve port of the multi-way valve.

6. The energy storage device according to claim 5, wherein The thermal management system further includes an electric heater, the coolant inlet of the electric heater is connected to the fourth valve port of the multi-way valve, and the coolant outlet of the electric heater is connected to the coolant inlet of the battery heat exchange plate.

7. The energy storage device according to claim 5 or 6, characterized in that, The thermal management system further includes a first pump and a second pump. The coolant outlet of the first pump is connected to the coolant inlet of the first evaporator, and the coolant inlet of the first pump is connected to the second valve port of the multi-way valve, or the coolant inlet of the first pump is connected to the coolant outlet of the first evaporator, and the coolant outlet of the first pump is connected to the first valve port of the multi-way valve; The coolant outlet of the second pump is connected to the coolant inlet of the condenser, and the coolant inlet of the second pump is connected to the sixth valve port of the multi-way valve. Alternatively, the coolant inlet of the second pump is connected to the coolant outlet of the condenser, and the coolant outlet of the second pump is connected to the coolant inlet of the power circuit heat exchange plate.

8. The energy storage device according to claim 7, characterized in that, The thermal management system further includes a replenishing kettle. When the coolant outlet of the second pump is connected to the coolant inlet of the condenser and the coolant inlet of the second pump is connected to the sixth valve port of the multi-way valve, the replenishing kettle is disposed between the second pump and the sixth valve port of the multi-way valve. Alternatively, when the coolant inlet of the second pump is connected to the coolant outlet of the condenser and the coolant outlet of the second pump is connected to the coolant inlet of the power circuit heat exchange plate, the replenishing kettle is disposed between the power circuit heat exchange plate and the fifth valve port of the multi-way valve.

9. The energy storage device according to any one of claims 1 to 8, characterized in that, The first evaporator is a plate heat exchanger; the second evaporator is a microchannel heat exchanger or a finned tube heat exchanger.

10. A photovoltaic energy storage system, characterized in that, It includes a power generation device, a power conversion device, and the energy storage device according to any one of claims 1 to 9. The power conversion device is connected between the power generation device and the energy storage device, and the power generation device is used to store the generated electric energy into the energy storage device through the power conversion device.

11. A charging network, characterized in that, It includes a charging pile and the energy storage device according to any one of claims 1 to 9. The charging pile is electrically connected to the energy storage device, and the energy storage device is used to provide electric energy for the charging pile.

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