CN219778997U

CN219778997U - energy storage system

Info

Publication number: CN219778997U
Application number: CN202321278333.1U
Authority: CN
Inventors: 万金钢
Original assignee: Yancheng Dafeng Csi Energy Storage Technology Co ltd; Atlas Energy Storage Technology Co ltd
Current assignee: Yancheng Dafeng Csi Energy Storage Technology Co ltd; Atlas Energy Storage Technology Co ltd
Priority date: 2023-05-24
Filing date: 2023-05-24
Publication date: 2023-09-29
Anticipated expiration: 2033-05-24

Abstract

The utility model discloses an energy storage system, which comprises at least one battery pack and a water chilling unit, wherein the battery pack is internally provided with at least one battery module, a battery management system, a heat exchange plate and an on-off piece; the water chilling unit is connected with the heat exchange plate; when the battery pack works normally, the heat exchange plate exchanges heat with the battery module, and the on-off piece closes the opening to cut off the communication between the interior of the heat exchange plate and the interior of the battery pack; when the battery management system detects that the voltage of the battery pack reaches a voltage preset threshold value and the temperature of the battery pack reaches a temperature preset threshold value, the on-off piece opens the opening, and the inside of the heat exchange plate is communicated with the inside of the battery pack, so that a heat exchange medium in the heat exchange plate flows into the battery pack. According to the energy storage system, heat spreading and burning of the battery pack can be effectively prevented, and the service performance of the energy storage system is improved.

Description

Energy storage system

Technical Field

The utility model relates to the technical field of energy storage systems, in particular to an energy storage system.

Background

In the related art, a fire-fighting device is arranged in the energy storage system to prevent the battery in the energy storage system from burning, and the fire-fighting device generally adopts a special fire extinguishing agent to isolate oxygen in the energy storage system and reduce the temperature of the battery. However, in the case of serious thermal runaway of the battery, the battery still generates heat spreading and even continues to burn, so that the fire-fighting effect of the fire-fighting device is poor, and the service performance of the energy storage system is affected.

Disclosure of Invention

The present utility model aims to solve at least one of the technical problems existing in the prior art. Therefore, an object of the present utility model is to provide an energy storage system, which can effectively prevent heat spreading and burning of a battery pack, and improve the service performance of the energy storage system.

An energy storage system according to an embodiment of the present utility model includes: the battery pack is internally provided with at least one battery module, a battery management system, a heat exchange plate and an on-off piece, the battery management system is electrically connected with the battery module, an opening is formed on the heat exchange plate, and the on-off piece is arranged at the opening; the water chilling unit is connected with the heat exchange plate; when the battery pack works normally, the heat exchange plate exchanges heat with the battery module, and the on-off piece closes the opening to separate the communication between the interior of the heat exchange plate and the interior of the battery pack; when the battery management system detects that the voltage of the battery pack reaches a voltage preset threshold value and the temperature of the battery pack reaches a temperature preset threshold value, the opening is opened by the on-off piece, and the inside of the heat exchange plate is communicated with the inside of the battery pack, so that a heat exchange medium in the heat exchange plate flows to the inside of the battery pack.

According to the energy storage system provided by the embodiment of the utility model, the on-off piece is arranged on the heat exchange plate, so that the heat exchange medium in the heat exchange plate can flow into the battery pack through the opening after the battery Bao Re is out of control, the temperature of the battery module is timely and effectively reduced, the heat spreading and burning of the battery module are avoided, the fire-fighting effect is better, the safety is higher, and the normal use of the battery pack is effectively ensured. In addition, the heat exchange plate not only can be used for a heat management device of the energy storage system, but also can play a role of a fire control device, the heat management device and the fire control device are combined into a whole, the fire control device is not required to be additionally arranged, the fire control design of the energy storage system is simplified, and meanwhile, the volume energy density of the energy storage system is improved. In addition, the fire control logic is simple, only the opening or closing of the on-off piece is required to be controlled, and the detection accuracy is high.

According to some embodiments of the utility model, the heat exchange plate is provided at the bottom of the battery module, and the opening is formed on a side surface of the heat exchange plate facing the battery module.

According to some embodiments of the utility model, the on-off member and the battery management system are located on the same side of the battery module.

According to some embodiments of the utility model, the on-off element is a solenoid valve in communication with the battery management system for controlling opening and closing of the solenoid valve.

According to some embodiments of the utility model, the plurality of battery packs, the solenoid valves of the plurality of battery packs and the battery management system are respectively and independently communicated.

According to some embodiments of the utility model, the chiller includes a pump and an expansion tank; the pump is communicated with the heat exchange plate through a first flow path and a second flow path, and the expansion tank is communicated with the first flow path; when the battery management system detects that the voltage of the battery pack reaches the voltage preset threshold value and the temperature of the battery pack reaches the temperature preset threshold value, the fluid in the expansion tank is suitable for flowing into the battery pack through the heat exchange plate through the first flow path.

According to some embodiments of the utility model, the energy storage system further comprises: an electrical device electrically connected to the battery pack, the electrical device comprising a high voltage circuit; and when the battery management system detects that the voltage of the battery pack reaches the voltage preset threshold value and the temperature of the battery pack reaches the temperature preset threshold value, the high-voltage circuit is disconnected.

According to some embodiments of the utility model, the electrical device is disposed on top of the water chiller, the electrical device and the water chiller being located on the same side of the battery pack.

According to some embodiments of the utility model, the heat exchange medium is a liquid.

According to some embodiments of the utility model, the battery module is completely submerged in the heat exchange medium when the battery management system detects that the voltage of the battery pack reaches a voltage preset threshold and the temperature of the battery pack reaches a temperature preset threshold.

Additional aspects and advantages of the utility model will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the utility model.

Drawings

The foregoing and/or additional aspects and advantages of the utility model will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic diagram of an energy storage system according to an embodiment of the present utility model;

fig. 2 is a schematic diagram of a battery pack of an energy storage system according to an embodiment of the present utility model.

Reference numerals:

100. an energy storage system;

1. a battery pack; 11. a battery module; 12. a battery management system;

13. a heat exchange plate; 14. a switching piece;

2. a water chiller; 21. a pump; 22. an expansion tank;

23. a first flow path; 231. a first main flow path; 232. a first branch flow path;

24. a second flow path; 241. a second main flow path; 242. a second branch flow path;

25. an electrical device; 26. a heat exchanger.

Detailed Description

Embodiments of the present utility model are described in detail below, with reference to the accompanying drawings, which are exemplary, and an energy storage system 100 according to an embodiment of the present utility model is described below with reference to fig. 1-1.

As shown in fig. 1, an energy storage system 100 according to an embodiment of the present utility model includes at least one battery pack 1 and a water chiller 2.

Specifically, at least one battery module 11, a battery management system 12, a heat exchange plate 13, and an on-off member 14 are provided in the battery pack 1, and the battery management system 12 is electrically connected to the battery module 11. For example, the battery management system 12 may measure parameters of the voltage, temperature change rate, etc. of the battery module 11. Thus, the battery management system 12 can be used to monitor the operating state of the battery module 11, and prevent or avoid abnormal conditions such as overdischarge, overcharge, and over-temperature of the battery. The heat exchange plate 13 is formed with an opening (not shown), and the on-off member 14 is provided at the opening. For example, when the on-off member 14 is opened, the inside of the heat exchange plate 13 communicates with the inside of the battery pack 1 through the on-off member 14; when the on-off member 14 is closed, the inside of the heat exchange plate 13 is blocked from the inside of the battery pack 1. The water chiller 2 is connected with a heat exchange plate 13. Therefore, the water chiller 2 can provide the heat exchange medium for exchanging heat with the battery module 11 for the heat exchange plate 13 to realize cooling, heating or heat preservation of the battery module 11, so as to be beneficial to normal use of the battery pack 1.

When the battery pack 1 works normally, the heat exchange plate 13 exchanges heat with the battery module 11, and the on-off piece 14 closes the opening to isolate the communication between the inside of the heat exchange plate 13 and the inside of the battery pack 1; when the battery management system 12 detects that the voltage of the battery pack 1 reaches the voltage preset threshold and the temperature of the battery pack 1 reaches the temperature preset threshold, the on-off piece 14 opens the opening, and the inside of the heat exchange plate 13 is communicated with the inside of the battery pack 1, so that the heat exchange medium in the heat exchange plate 13 flows into the battery pack 1.

For example, when the battery pack 1 is in normal operation, the heat exchange plate 13 can exchange heat with the battery module 11 in the battery pack 1, so as to be beneficial to normal use of the battery pack 1. When the battery management system 12 detects that the battery pack 1 is abnormal, for example, the voltage in the battery pack 1 suddenly becomes zero, and the temperature of the battery pack 1 exceeds a temperature preset threshold, that is, when the battery pack 1 is abnormal, the opening and closing member 14 opens the opening, and the heat exchange medium in the heat exchange plate 13 can flow into the battery pack 1 through the opening, contact with the battery module 11 in the battery pack 1 to reduce the temperature of the battery module 11, and prevent the heat of the battery pack 1 from continuing to spread after thermal runaway. Therefore, by arranging the on-off piece 14 on the heat exchange plate 13, the heat exchange plate 13 can be used for a heat management device of the energy storage system 100 (namely, the heat exchange plate 13 performs heat exchange with the battery module 11), can also play a role of a fire protection device (namely, the heat spreading of the battery module 11 and the combustion of the battery module 11 are prevented), does not need to additionally arrange the fire protection device, simplifies the fire protection design of the energy storage system 100, improves the volume energy density of the energy storage system 100, and can also reduce the production cost of the energy storage system 100. In addition, compared with the prior art that the fire extinguishing agent is adopted to cool and flame retardant the battery module 11, the energy storage system 100 has better fire-fighting effect, higher fire-fighting effect for the protection grade of more than IP65, higher safety and difficult firing and difficult heat spreading of the battery module 11, and further ensures the normal use of the battery pack 1. In addition, the fire control logic is simple, and only the opening or closing of the on-off piece 14 is required to be controlled to play a role in fire control. Moreover, by detecting whether the battery module 11 is abnormal or not by the battery management system 12, the detection accuracy of the energy storage system 100 is higher without considering the insensitive cases of sensor detection temperature, smoke detection, and the like.

According to the energy storage system 100 provided by the embodiment of the utility model, the on-off piece 14 is arranged on the heat exchange plate 13, so that the heat exchange medium in the heat exchange plate 13 can flow into the battery pack 1 through the opening in time after the battery pack 1 is out of control, the temperature of the battery module 11 can be timely and effectively reduced, the heat spreading and burning of the battery module 11 can be avoided, the fire-fighting effect is good, the safety is improved, and the normal use of the battery pack 1 is effectively ensured. In addition, the heat exchange plate 13 can be used for a heat management device of the energy storage system 100, and also can play a role of a fire-fighting device, the heat management device and the fire-fighting device are integrated into a whole, and the fire-fighting device is not required to be additionally arranged, so that the fire-fighting design of the energy storage system 100 is simplified, and meanwhile, the volume energy density of the energy storage system 100 is improved. In addition, the fire control logic is simple, only the opening or closing of the on-off piece 14 needs to be controlled, and the detection accuracy is high.

According to some embodiments of the present utility model, referring to fig. 1, a heat exchange plate 13 is provided at the bottom of the battery module 11, and an opening is formed on a side surface of the heat exchange plate 13 facing the battery module 11. For example, in the example of fig. 1, the heat exchange plate 13 is located under the battery module 11, and an opening is formed at the upper surface of the heat exchange plate 13. This arrangement facilitates sufficient contact between the heat exchange plate 13 and the battery module 11, thereby facilitating heat exchange between the heat exchange plate 13 and the battery module 11. In addition, when the opening is opened by the on-off piece 14, the heat exchange medium in the heat exchange plate 13 can quickly flow into the battery pack 1, so that the heat exchange medium can timely contact with the battery module 11, and the fire-fighting effect of the energy storage system 100 is improved.

Alternatively, in connection with fig. 2, the on-off member 14 and the battery management system 12 are located on the same side of the battery module 11. For example, in the example of fig. 2, a plurality of battery modules 11 are provided in the battery pack 1, and the on-off member 14 and the battery management system 12 are located on the left side of the plurality of battery modules 11. In the description of the present utility model, "plurality" means two or more. Thus, when the heat exchange medium flows into the battery pack 1, the heat exchange medium may flow along the length direction (e.g., the left-right direction in fig. 2) of the battery pack 1, so that the heat exchange medium is in sufficient contact with the battery module 11, thereby ensuring the fire-fighting effect of the energy storage system 100. In addition, the space layout in the battery pack 1 is reasonable, the space occupied by the on-off piece 14 and the battery management system 12 in the battery pack 1 is reduced, the space utilization rate in the battery pack 1 is improved, the integration level of the battery pack 1 is improved, and a plurality of battery modules 11 can be arranged in the battery pack 1.

According to some embodiments of the present utility model, the on-off member 14 is a solenoid valve that communicates with the battery management system 12, and the battery management system 12 is configured to control the opening and closing of the solenoid valve. For example, when the battery management system 12 detects that the voltage of the battery pack 1 reaches the voltage preset threshold and the temperature of the battery pack 1 reaches the temperature preset threshold, that is, after the battery management system 12 detects that the battery pack 1 is thermally out of control, the battery management system 12 may control the solenoid valve to open so that the heat exchange medium in the heat exchange plate 13 flows into the battery pack 1. Thus, the battery management system 12 has high detection accuracy and simple control, and the operation of the heat exchange plate 13 can be changed by controlling the opening or closing of the solenoid valve only to switch the operation state of the energy storage system 100 (for example, from the thermal management device operation to the fire control device operation). In addition, the electromagnetic valve has a small structure and is convenient to use.

Optionally, referring to fig. 1, the battery pack 1 is a plurality of, and the solenoid valves of the plurality of battery packs 1 are respectively and independently communicated with the battery management system 12. For example, in the example of fig. 1, the energy storage system 100 includes twelve battery packs 1, each battery pack 1 having a battery management system 12, heat exchange plates 13, and solenoid valves disposed therein, the solenoid valves in each battery pack 1 being in independent communication with the battery management system 12. That is, after a thermal runaway of one of the plurality of battery packs 1, the battery management system 12 in the thermal runaway battery pack 1 may control the corresponding solenoid valve to open to reduce the temperature of the battery module 11 in the thermal runaway battery pack 1. Therefore, the battery pack 1 with thermal runaway can be accurately identified, the normal use of other battery packs 1 can not be influenced after the electromagnetic valve is opened, and an operator only needs to replace the battery pack 1 with a problem, so that the use cost of the energy storage system 100 is further reduced, and the maintenance of the energy storage system 100 is also facilitated.

According to some embodiments of the present utility model, referring to fig. 1, a chiller 2 includes a pump 21 and an expansion tank 22, the pump 21 and the heat exchanger plate 13 are in communication via a first flow path 23 and a second flow path 24, and the expansion tank 22 is in communication with the first flow path 23. When the battery management system 12 detects that the voltage of the battery pack 1 reaches the voltage preset threshold and the temperature of the battery pack 1 reaches the temperature preset threshold, the fluid in the expansion tank 22 is adapted to flow through the first flow path 23 via the heat exchange plate 13 to the inside of the battery pack 1.

For example, in the example of fig. 1, an expansion tank 22 is provided on the second flow path 24 and is located between the pump 21 and the heat exchange plate 13. When the battery pack 1 is operating normally, the heat exchange medium may circulate between the pump 21 and the heat exchange plates 13 through the first flow path 23 and the second flow path 24. For example, the heat exchange medium flows into the heat exchange plate 13 through the first flow path 23, exchanges heat with the battery module 11 during the flow in the heat exchange plate 13, and then takes away heat of the battery module 11 and returns to the pump 21 through the second flow path 24, thereby completing one cycle. During this process, expansion tank 22 may be used to supplement the heat exchange medium in heat exchange plate 13, and the pressure may be regulated to facilitate the flow of the heat exchange medium. In the above-described circulation process, taking a case in which the heat exchange medium is used to cool the battery module 11, a heat exchanger 26 may be provided on the first flow path 23 or at the junction of the first flow path 23 and the second flow path 24, and the heat exchanger 26 is used to exchange heat with the heat exchange medium flowing out of the heat exchange plate 13, so that the temperature of the heat exchange medium that is again returned to the heat exchange plate 13 may be reduced. Of course, the heat exchanger 26 may also be arranged adjacent to the second flow path 24 for heat exchange with the heat exchange medium flowing out of the heat exchange plate 13 for taking away heat of the heat exchange medium.

When the battery pack 1 is abnormal, the battery management system 12 controls the electromagnetic valve to open an opening, the heat exchange medium in the heat exchange plate 13 flows into the battery pack 1, the pressure in the expansion tank 22 changes to make the heat exchange medium in the expansion tank 22 flow out, and the heat exchange medium flows into the battery pack 1 through the heat exchange plate 13 through the first flow path 23 under the action of the pump 21 to reduce the temperature of the battery module 11. Therefore, the arrangement of the pump 21 and the expansion tank 22 is beneficial to the heat exchange medium in the expansion tank 22 to flow into the heat exchange plate 13, and a source of the heat exchange medium is also provided, so that the battery pack 1 can be quickly cooled in time, and the battery module 11 is prevented from being further combusted. In addition, only one set of connecting pipelines is needed to be arranged in the energy storage system 100, and pipelines for fire fighting are not needed to be arranged independently, so that the integration level of the energy storage system 100 is improved, and the use cost of the energy storage system 100 is further reduced.

According to some embodiments of the present utility model, in combination with fig. 1, the energy storage system 100 further comprises an electrical device 25, the electrical device 25 being electrically connected with the battery pack 1, the electrical device 25 comprising a high voltage circuit. When the battery management system 12 detects that the voltage of the battery pack 1 reaches the voltage preset threshold and the temperature of the battery pack 1 reaches the temperature preset threshold, the high-voltage circuit is turned off. Therefore, when the battery management system 12 detects that the battery pack 1 is abnormal, the circuit connection between the abnormal battery pack 1 and other normal battery packs 1 is cut off in time, and the electromagnetic valve is controlled to be opened, so that the other battery packs 1 can be continuously used normally, and the normal use of the energy storage system 100 is ensured. In addition, the safety of the energy storage system 100 is also improved.

Further, referring to fig. 1, an electrical device 25 is provided on the top of the water chiller 2, and the electrical device 25 and the water chiller 2 are located on the same side of the battery pack 1. For example, in the example of fig. 1, a plurality of battery packs 1 are arranged on the left side within the energy storage system 100, the water chiller 2 and the electrical device 25 are provided on the right side within the energy storage system 100, and the electrical device 25 is located above the water chiller 2. By the arrangement, the battery packs 1, the electric devices 25 and the water chilling unit 2 are reasonably distributed, the internal space of the energy storage system 100 is effectively utilized, and the space utilization rate of the energy storage system 100 is improved. In addition, the electric device 25 and the water chiller 2 do not interfere with each other, which is beneficial to normal use of each component and circuit connection of pipeline connection between each component, thereby facilitating normal use of the energy storage system 100.

According to some embodiments of the utility model, the heat exchange medium is a liquid. When the battery management system 12 detects that the voltage of the battery pack 1 reaches the voltage preset threshold and the temperature of the battery pack 1 reaches the temperature preset threshold, the cooling liquid in the heat exchange plate 13 can flow into the battery pack 1 in time so as to soak the battery module 11 in the heat exchange medium. Compared with a gaseous heat exchange medium, the temperature of the battery module 11 can be reduced more timely, the duration is long, and the fire-fighting effect is better, so that the combustion of the battery module 11 is effectively avoided, and the fire-fighting performance of the energy storage system 100 is improved.

Further, when the battery management system 12 detects that the voltage of the battery pack 1 reaches the voltage preset threshold and the temperature of the battery pack 1 reaches the temperature preset threshold, the battery module 11 is completely immersed in the heat exchange medium. Therefore, the heat exchange medium can fully contact with each side surface of the battery module 11 by completely immersing the battery module 11 in the heat exchange medium flowing into the battery pack 1, so that the effects of preventing fire and extinguishing fire are achieved while the temperature of the battery module 11 is reduced, the use safety of the battery pack 1 is further improved, and the fire-fighting performance of the energy storage system 100 is further improved.

Alternatively, referring to fig. 1, the first flow path 23 includes a first main flow path 231 and a plurality of first branch flow paths 232, one end of the first main flow path 231 is connected to the pump 21, the other end of the first main flow path 231 is connected to one end of the plurality of first branch flow paths 232, respectively, and the other end of each first branch flow path 232 is connected to a different battery pack 1, respectively. The second flow path 24 includes a second main flow path 241 and a plurality of second branch flow paths 242, one end of the second main flow path 241 is connected to one ends of the plurality of second branch flow paths 242, the other end of the second main flow path 241 is connected to the pump 21, the expansion tank 22 is connected to the first main flow path 231, and the other end of each second branch flow path 242 is connected to a different battery pack 1. Thus, the heat exchange medium in the first main flow path 231 can flow into the heat exchange plates 13 of the different battery packs 1 through the plurality of first branch flow paths 232, and the heat exchange medium after heat exchange with the battery packs 1 can flow into the second main flow path 241 through the plurality of second branch flow paths 242, and then flow back to the pump 21 to exchange heat with the heat exchanger 26. So set up, the heat transfer medium between a plurality of battery packs 1 does not influence each other, and the temperature of the heat transfer medium that flows in a plurality of battery packs 1 is roughly the same to the heat transfer medium that flows out from a plurality of battery packs 1 can not contact with other battery packs 1, can flow back to heat exchanger 26 department through a plurality of second branch flow paths 242, thereby guaranteed the heat transfer effect to a plurality of battery packs 1, in order to be favorable to the normal use of a plurality of battery packs 1 more. When the electromagnetic valve is opened, the heat exchange medium in the expansion tank 22 can also flow into different battery packs 1 through the first main flow path 231 and the plurality of first branch flow paths 232, and abnormal battery packs 1 can be controlled in time, so that the control accuracy of the energy storage system 100 is further improved.

Other configurations and operations of the energy storage system 100 according to embodiments of the present utility model are known to those of ordinary skill in the art and will not be described in detail herein.

In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present utility model.

In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the utility model. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples.

While embodiments of the present utility model have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the spirit and principles of the utility model, the scope of which is defined by the claims and their equivalents.

Claims

1. An energy storage system, comprising:

the battery pack is internally provided with at least one battery module, a battery management system, a heat exchange plate and an on-off piece, the battery management system is electrically connected with the battery module, an opening is formed on the heat exchange plate, and the on-off piece is arranged at the opening;

the water chilling unit is connected with the heat exchange plate;

when the battery pack works normally, the heat exchange plate exchanges heat with the battery module, and the on-off piece closes the opening to separate the communication between the interior of the heat exchange plate and the interior of the battery pack;

when the battery management system detects that the voltage of the battery pack reaches a voltage preset threshold value and the temperature of the battery pack reaches a temperature preset threshold value, the opening is opened by the on-off piece, and the inside of the heat exchange plate is communicated with the inside of the battery pack, so that a heat exchange medium in the heat exchange plate flows to the inside of the battery pack.

2. The energy storage system according to claim 1, wherein the heat exchange plate is provided at a bottom of the battery module, and the opening is formed on a surface of the heat exchange plate facing the battery module.

3. The energy storage system of claim 1, wherein the on-off member and the battery management system are located on the same side of the battery module.

4. The energy storage system of claim 1, wherein the on-off member is a solenoid valve in communication with the battery management system for controlling opening and closing of the solenoid valve.

5. The energy storage system of claim 4, wherein said battery pack is a plurality of said solenoid valves of said battery packs in separate communication with said battery management system.

6. The energy storage system of claim 1, wherein the chiller comprises a pump and an expansion tank;

the pump is communicated with the heat exchange plate through a first flow path and a second flow path, and the expansion tank is communicated with the first flow path;

when the battery management system detects that the voltage of the battery pack reaches the voltage preset threshold value and the temperature of the battery pack reaches the temperature preset threshold value, the fluid in the expansion tank is suitable for flowing into the battery pack through the heat exchange plate through the first flow path.

7. The energy storage system of claim 1, further comprising:

an electrical device electrically connected to the battery pack, the electrical device comprising a high voltage circuit;

and when the battery management system detects that the voltage of the battery pack reaches the voltage preset threshold value and the temperature of the battery pack reaches the temperature preset threshold value, the high-voltage circuit is disconnected.

8. The energy storage system of claim 7, wherein the electrical device is disposed on top of the chiller, the electrical device and the chiller being located on the same side of the battery pack.

9. The energy storage system of any of claims 1-8, wherein the heat exchange medium is a liquid.

10. The energy storage system of claim 9, wherein the battery module is completely submerged in the heat exchange medium when the battery management system detects that the voltage of the battery pack reaches a voltage preset threshold and the temperature of the battery pack reaches a temperature preset threshold.