Immersed energy storage device and energy storage system

Abstract

The invention provides an immersed energy storage device and an energy storage system, the energy storage device comprises an immersion box assembly, the immersion box assembly comprises a box body and a battery unit, the battery unit is arranged in the box body, immersion liquid flowing circularly is arranged in the box body, and the battery unit is completely immersed in the immersion liquid; the temperature adjusting device is connected with the immersion box assembly and used for adjusting the temperature of the immersion liquid; a partition plate is arranged in the box body and used for dividing a cavity in the box body into an immersion cavity and an overflow cavity, and a certain distance exists between the top end of the partition plate and the inner wall of a top plate of the box body, so that the immersion cavity and the overflow cavity are communicated on the upper portion of the partition plate. Through the arrangement of the partition plates in the immersion box, the liquid level of the immersion box in the use process is always kept at a stable height, the immersion height of the battery is ensured, the temperature uniformity of the battery is ensured, through the arrangement of the spoilers, a temperature boundary layer between the surface of the battery unit and the immersion liquid is damaged, and the temperature adjusting effect is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to an immersion energy storage device and an energy storage system. Background Art

[0002] In the field of energy storage technology, it is crucial to keep the battery operating within an appropriate temperature range. Overheating of the battery will affect its performance and life, and may even cause safety accidents. In existing technologies, technical means such as air cooling and air conditioning are usually used to control the battery temperature. However, air cooling and natural regulation are inefficient, air conditioning regulation consumes a lot of energy, and it is impossible to achieve precise temperature control of the battery. It is easy for individual battery temperature peaks to be too high, which is not conducive to the stable operation of the battery.

[0003] Liquid cooling technology, as an emerging cooling method in the energy storage field, has developed rapidly. It has high temperature control efficiency and can achieve precise control of battery temperature. In particular, immersion energy storage technology immerses the battery module in immersion liquid, which can evenly adjust the battery surface temperature with extremely high temperature regulation efficiency.

[0004] Chinese patent CN202410027111.5 discloses an immersion energy storage battery box, including a box body, a battery module and a guide member, the guide member and the battery module are both arranged in a receiving cavity inside the box body; the box body is provided with a liquid inlet and a liquid outlet; along the arrangement direction perpendicular to the battery cells, two opposite sides of the battery module are provided with side channels; the gap between the battery module and the top cavity wall of the receiving cavity forms a top channel, and the gap between the battery module and the bottom cavity wall of the receiving cavity forms a bottom channel; the bottom channel is connected to the liquid inlet, and the top channel and the side channel are both connected to the liquid outlet; the guide member is provided with a top guide channel and a side guide channel, the bottom channel is connected to the top channel only through the top guide channel, and the bottom channel is connected to the side channel only through the side guide channel. The immersion energy storage battery box provided by the patent can quickly take away the heat of the battery module and ensure the stability and safety of the battery module when in use. However, during the application process, it was found that the liquid level of the immersion liquid in the battery box was unstable, and the liquid level was often lower than the target level. The battery was not completely immersed and the battery temperature was unevenly adjusted, posing certain safety hazards. Summary of the invention

[0005] The problem solved by the present invention is that in the prior art, the liquid level of the immersion liquid in the battery box is unstable, and the liquid level is often lower than the target liquid level. The battery is not completely immersed, the battery temperature is unevenly adjusted, and there are certain safety hazards.

[0006] In order to solve the above problems, the present invention discloses an immersion energy storage device, comprising:

[0007] An immersion tank assembly comprises a tank body and a battery cell, wherein the battery cell is arranged in the tank body, a circulating immersion liquid is arranged in the tank body, and the battery cell is completely immersed in the immersion liquid;

[0008] a temperature regulating device, the temperature regulating device being connected to the immersion tank assembly and being used for regulating the temperature of the immersion liquid circulating therein;

[0009] A partition is provided in the box body, and the partition is used to separate the chamber inside the box body into an immersion chamber and an overflow chamber. There is a certain distance between the top of the partition and the inner wall of the box body top plate, so that the immersion chamber and the overflow chamber are connected at the upper part of the partition.

[0010] Furthermore, a spoiler is provided on the inner wall of the immersion chamber and on the side of the partition close to the liquid inlet chamber, and the spoiler extends in the direction of the battery unit.

[0011] Furthermore, the spoiler includes a long spoiler and a short spoiler, the length of the long spoiler extending in the direction of the battery cell is greater than the length of the short spoiler extending in the direction of the battery cell, and the long spoiler and the short spoiler on the same wall are arranged at intervals.

[0012] Furthermore, the extension length of the long spoiler is recorded as h1, the extension length of the short spoiler is recorded as h2, and the distance between the wall where the spoiler is located and the battery unit is recorded as H, then 2h1<H<3h1, h2

[0013] Furthermore, a liquid input part is provided at the bottom of the box body, and the liquid input part includes a liquid inlet cavity, and the liquid inlet cavity is arranged corresponding to the immersion cavity, and a plurality of liquid inlet holes are arranged between the liquid inlet cavity and the immersion cavity. The liquid inlet cavity is connected to a liquid input pipeline, and the liquid input pipeline is connected to the liquid outlet of the temperature regulating device. The liquid input pipeline is arranged on a side away from the partition, and is used to inject immersion liquid into the liquid inlet cavity.

[0014] Furthermore, more than two battery cells are arranged in the box body, and certain gaps are maintained between adjacent battery cells, between a battery cell and a wall of the box body, and between a battery cell and a partition, and a plurality of the liquid inlet holes are evenly distributed in the gaps.

[0015] Furthermore, a liquid drain pipeline is also provided on the liquid input part, and the liquid drain pipeline is arranged on a side away from the partition, and the liquid drain pipeline is used to drain the immersion liquid in the liquid input part and the box body when necessary.

[0016] Furthermore, the bottom surface of the liquid inlet cavity gradually rises from a direction close to the liquid input pipeline to a direction close to the partition.

[0017] ​Furthermore, the overflow chamber is connected to an overflow pipeline, and the overflow pipeline is connected to the liquid inlet of the temperature regulating device.

[0018] The present invention also discloses an energy storage system, comprising the energy storage device as described above.

[0019] Compared with the prior art, the submerged energy storage device and energy storage system described in the present invention have the following advantages:

[0020] The present invention divides the space in the immersion box into an immersion chamber and an overflow chamber connected at the top by setting a partition in the immersion box, so that the immersion liquid in the immersion chamber does not participate in the circulation of the immersion liquid before reaching the top of the partition, so that the liquid level of the immersion box is always maintained at a stable height during use, ensuring the immersion height of the battery and the uniformity of the battery temperature. By setting the liquid inlet part, multi-point all-round liquid inflow is achieved, and the uniformity and stability of the liquid inflow are maintained. By setting the spoiler, the temperature boundary layer between the battery cell surface and the immersion liquid is destroyed, avoiding the long-term retention and contact of the local liquid on the battery cell surface, and significantly improving the temperature regulation effect of the immersion. The energy storage device provided by the present invention has a simple structure, significantly improves the temperature regulation effect of the battery cell, and ensures the stable and safe operation of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the three-dimensional structure of the immersion tank assembly according to an embodiment of the present invention;

[0022] Figure 2 It is a schematic diagram of the three-dimensional structure of the immersion box assembly according to an embodiment of the present invention from another angle;

[0023] Figure 3 is a cross-sectional view of an immersion tank assembly according to an embodiment of the present invention;

[0024] Figure 4 A cross-sectional view of the immersion tank assembly according to an embodiment of the present invention from another perspective;

[0025] Figure 5 It is a partial cross-sectional schematic diagram of the cooperation arrangement of the immersion tank assembly, the pressure relief channel and the shell of the energy storage system according to an embodiment of the present invention;

[0026] Figure 6 It is a schematic diagram of the three-dimensional structure of the temperature regulating device according to an embodiment of the present invention;

[0027] Figure 7 It is a three-dimensional structural schematic diagram of the temperature regulating device according to an embodiment of the present invention from another angle;

[0028] Figure 8 It is a front view of the temperature regulating device according to an embodiment of the present invention;

[0029] Fig. 9 for Figure 8 A schematic diagram of the cross-sectional structure of the temperature regulating device along the AA position when the first magnetized body is attached to the outer peripheral wall of the heat exchange structure;

[0030] Fig.10 for Figure 8 A schematic diagram of the cross-sectional structure of the temperature regulating device along the BB position when the first magnetized body is attached to the outer peripheral wall of the heat exchange structure;

[0031] Fig.11 for Figure 8 A schematic diagram of the cross-sectional structure of the temperature regulating device along the BB position when the second magnetized body is attached to the outer peripheral wall of the heat exchange structure;

[0032] Fig.12 This is a schematic diagram of the connection state between the immersion box assembly and the temperature adjustment device according to an embodiment of the present invention;

[0033] Fig.13 This is a schematic diagram of a three-dimensional structure in which a second box body is arranged outside the immersion box assembly according to an embodiment of the present invention;

[0034] Fig.14 It is a schematic cross-sectional structure diagram of a case where a second box body is disposed outside the immersion box assembly according to an embodiment of the present invention;

[0035] Fig.15 It is a schematic diagram of the three-dimensional structure of the second box body and the liquid receiving tray according to an embodiment of the present invention.

[0036] Description of reference numerals:

[0037] 100, immersion box assembly; 110, box body; 111, liquid inlet hole; 120, battery unit; 130, partition; 140, immersion chamber; 150, overflow chamber; 160, liquid input part; 161, liquid input pipeline; 1611, first valve body; 162, liquid emptying pipeline; 1621, second valve body; 163, overflow pipeline; 1631, fifth valve body; 164, liquid inlet chamber; 165, liquid inlet slope; 166, liquid output pipeline; 1661, third valve body; 170, spoiler; 180, drying part; 190, pressure relief plate; 200, pressure relief assembly; 210, pressure relief channel; 220, waterproof board; 230, anti-toxic structure; 2 21. Water-conducting slope; 222. Waterproof main board; 223. One-way movable plate; 300. Shell; 310. Ventilation part; 320. Drainage part; 400. Temperature regulating device; 410. Temperature regulating box; 420. External magnet; 430. Internal magnet; 440. Heat exchange structure; 441. Liquid inlet; 442. Liquid outlet; 443. Heat exchange cavity; 450. Fin; 460. First magnet; 470. Second magnet; 480. Slide rail; 500. Waste liquid box; 510. Waste liquid pipe; 520. Fourth valve body; 600. Pump body; 700. Second box body; 710. Liquid receiving tray; 711. Concave groove; 712. Step part; 713. Drainage pipe. DETAILED DESCRIPTION

[0038] To make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0039] An immersion energy storage device and an energy storage system according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[0040] This embodiment provides an immersion energy storage device, such as Figure 1-Figure 15 As shown, including:

[0041] The immersion tank assembly 100 includes a tank body 110 and a battery unit 120. The battery unit 120 is disposed in the tank body 110. A circulating immersion liquid is disposed in the tank body 110. The battery unit 120 is completely immersed in the immersion liquid.

[0042] A temperature regulating device 400, the temperature regulating device 400 is connected to the immersion tank assembly 100 and is used to regulate the temperature of the immersion liquid circulating therein;

[0043] Among them, a partition 130 is arranged in the box body 110, and the partition 130 is used to separate the chamber inside the box body 110 into an immersion chamber 140 and an overflow chamber 150. There is a certain distance between the top of the partition 130 and the inner wall of the top plate of the box body 110, so that the immersion chamber 140 and the overflow chamber 150 are connected at the upper part of the partition 130.

[0044] In the prior art, during the operation of the immersion energy storage system, the liquid level is often unstable. In some cases, the battery cell 120 cannot be fully controlled and adjusted, which easily leads to problems such as temperature imbalance and excessive temperature difference. Safety problems such as thermal runaway are prone to occur during long-term operation, affecting the safe and stable operation of the battery cell 120. In actual operation, the liquid level is usually adjusted by controlling the flow rate of the inlet and outlet pipes to keep it within a safe working range. However, the researchers of this application found that the liquid level cannot be kept stable in this case. After research, it was found that as the heat exchange between the battery cell 120 and the immersion liquid proceeds, the viscosity of the immersion liquid will change accordingly, resulting in different viscosities of the immersion liquid at the inlet and outlet positions of the immersion tank assembly 100. Under normal circumstances, as the temperature increases, the viscosity of the immersion liquid will decrease to a certain extent, so that its outlet flow rate is slightly different from the inlet flow rate. As the energy storage system runs for a long time, these differences accumulate to form differences in the liquid level, affecting the operational safety of the battery cell 120. In this embodiment, the immersion chamber 140 and the overflow chamber 150 are formed in the box body 110 by setting the partition 130. The immersion liquid in the immersion chamber 140 needs to cross the partition 130 to enter the overflow chamber 150 and be discharged, so that the liquid level in the immersion chamber 140 is stably maintained at the same height as the partition 130, so that the stability of the liquid level in the box body 110 is achieved by using a simple structure, so that the battery unit 120 is in a stable temperature regulation environment, so that it can operate safely and stably. In addition, as the temperature increases during the heat exchange process, the density of the immersion liquid gradually decreases, and it is usually located near the upper layer of the immersion liquid. Therefore, the immersion liquid overflowing through the partition 130 is usually also the part with a relatively high temperature in the immersion chamber 140, which helps to retain the immersion liquid with a lower temperature in the immersion chamber 140 and improve its temperature regulation ability. It should be understood that the battery unit 120 described in this embodiment is a battery cell or a battery module. It should be noted that the immersion liquid used in the present application is the immersion liquid commonly used in the current immersion energy storage system, such as fluorinated liquid, etc., which will not be further described or limited here.

[0045] As one of the optional embodiments, Figure 1 , Figure 2As shown, a liquid input part 160 is provided at the bottom of the box body 110, and the liquid input part 160 includes a liquid inlet cavity 164, and the liquid inlet cavity 164 is arranged corresponding to the immersion cavity 140, and a plurality of liquid inlet holes 111 are arranged between the liquid inlet cavity 164 and the immersion cavity 140, and the liquid inlet cavity 164 is connected to a liquid input pipeline 161, and the liquid input pipeline 161 is connected to the liquid outlet 442 of the temperature regulating device 400, and the liquid input pipeline 161 is arranged on a side away from the partition 130, and is used for injecting immersion liquid into the liquid inlet cavity 164. It should be understood that more than one battery cell 120 is arranged in the immersion chamber 140. Directly injecting immersion liquid into the immersion chamber 140 is likely to interfere with the battery cell 120, affecting the flow state of the immersion liquid in the immersion chamber 140. The setting of the liquid input part 160 can avoid directly inputting immersion liquid into the immersion chamber 140, which helps to adjust the flow state of the immersion liquid and ensure its heat exchange efficiency. The liquid input pipeline 161 is arranged on the side away from the partition 130, which helps to improve the flow path of the immersion liquid in the box body 110 and improve its heat exchange efficiency.

[0046] As one of the preferred embodiments, more than two battery cells 120 are arranged in the box 110, and a certain gap is maintained between adjacent battery cells 120, between the battery cells 120 and the wall of the box 110, and between the battery cells 120 and the partition 130, and a plurality of the liquid inlet holes 111 are evenly distributed in the gap. Figure 3 As shown, four battery cells 120 are arranged in the immersion chamber 140. There is a certain interval between the leftmost battery cell 120 and the left wall, there is a certain interval between the rightmost battery cell 120 and the partition 130, and there is also a certain interval between adjacent battery cells 120. The liquid inlet holes 111 are divided into five columns and evenly distributed in the above five intervals. Through the above arrangement, the dispersed inlet of the immersion liquid is achieved without interfering with the battery cells 120, thereby improving the heat exchange efficiency between the immersion liquid and the battery cells 120.

[0047] As another preferred embodiment, Figure 4 As shown, the bottom surface of the liquid inlet cavity 164 gradually rises from the direction close to the liquid input pipeline 161 to the direction close to the partition 130, forming a liquid inlet slope 165. It should be understood that if the bottom surface of the liquid inlet cavity 164 is a plane, as the immersion liquid flows into the box body 110, the hydraulic pressure on the side close to the partition 130 gradually decreases, and the liquid cannot be stably supplied to the box body 110, and the immersion liquid in the box body 110 may flow back. Through the above arrangement, the hydraulic pressure of the immersion liquid in the liquid inlet cavity 164 from the direction close to the liquid input pipeline 161 to the direction close to the partition 130 is kept stable, thereby maintaining a stable liquid supply.

[0048] As one of the optional embodiments, the lower end of the partition 130 can be set on the bottom plate of the box body 110, or it can extend downward into the liquid input part 160. In this case, the bottom plate of the box body 110 in the overflow chamber 150 is removed, and the bottom plate of the liquid input part 160 serves as the bottom plate of the overflow chamber 150. This arrangement allows the size of the outer side of the lower part of the immersion tank assembly 100 to remain consistent, so that it forms a regular shape, which is convenient for its installation and transportation, and also appropriately expands the capacity of the overflow chamber 150.

[0049] As another preferred embodiment, Figure 4 As shown, a spoiler 170 is provided on the inner wall of the immersion chamber 140 and on one side of the partition 130 close to the liquid inlet chamber 164, and the spoiler 170 extends in the direction of the battery cell 120. During operation, a temperature boundary layer will be formed at the position where the surface of the battery cell 120 contacts the immersion liquid. This temperature boundary layer will form a temperature gradient in a very thin area close to the surface of the battery cell 120, which will have a great negative impact on the convective heat transfer during the flow of the immersion liquid, and seriously affect the heat exchange effect between the immersion liquid and the battery cell 120. The spoiler 170 is used to change the flow state of the immersion liquid in the immersion chamber 140, so that a certain turbulence is formed during the flow process. This turbulence can destroy the temperature boundary layer on the surface of the battery cell 120, thereby significantly improving its heat exchange efficiency and improving the temperature control effect. Preferably, a spoiler vertical plate may be provided between adjacent battery cells 120, and spoiler pieces 170 extending toward the battery cells 120 on both sides may be provided on the spoiler vertical plate to further improve the turbulent state of the immersion liquid. Figure 3 , Figure 4 The front wall, rear wall, left wall, and right wall (the wall surface of the partition 130 facing the battery unit 120 ) shown are not described in detail here.

[0050] As one of the embodiments, Figure 4 As shown, the lengths of the spoilers 170 extending toward the battery unit 120 are not consistent. This arrangement can further improve the disorder of the turbulent flow of the immersion liquid, thereby suppressing the formation of a temperature boundary layer and improving the heat exchange efficiency.

[0051] Optional, such as Figure 4As shown, the spoiler 170 includes a long spoiler and a short spoiler. The length of the long spoiler extending in the direction of the battery cell 120 (hereinafter referred to as the extension length) is greater than the length of the short spoiler extending in the direction of the battery cell 120. The long spoiler and the short spoiler on the same wall are arranged at intervals. Through the above arrangement, the two adjacent spoilers 170 have different turbulent effects on the immersion liquid, thereby forming a turbulent shape, which is convenient for destroying the temperature boundary layer and improving the heat exchange efficiency. It should be noted that the end of the spoiler 170 away from the wall can be semicircular, triangular, or inclined, and the shapes of the ends of adjacent spoilers 170 away from the wall can be the same or different.

[0052] Specifically, the extension length of the long spoiler is recorded as h1, the extension length of the short spoiler is recorded as h2, and the distance between the wall where the spoiler 170 is located and the battery cell 120 is recorded as H, then 2h1<H<3h1, h2

[0053] As one of the optional embodiments, the overflow chamber 150 is connected to an overflow pipeline 163, and the overflow pipeline 163 is connected to the liquid inlet 441 of the temperature adjustment device 400. Through the above arrangement, the immersion liquid overflowing from the partition 130 flows into the temperature adjustment device 400 for temperature adjustment, and the adjusted immersion liquid is then transported into the liquid input part 160 through the liquid outlet 442 and the liquid input pipeline 161, and supplied to the box 110, completing the circulation of the immersion liquid during normal operation.

[0054] ​In another optional embodiment, the liquid input part 160 is further provided with a liquid draining pipeline 162, which is arranged on a side away from the partition 130, and is used to drain the immersion liquid in the liquid input part 160 and the box 110 when necessary. When thermal runaway of battery solution leakage occurs in the battery cell 120 or the battery cell 120 or the box 110 needs to be maintained and repaired, the immersion liquid in the liquid input part 160 and the box 110 needs to be drained first. Since the overflow chamber 150 is not connected to the bottom of the immersion chamber 140, the immersion liquid in the box 110 and the liquid input part 160 cannot be drained. The liquid draining pipeline 162 is arranged on a side away from the partition 130. With the help of the liquid inlet slope 165, the immersion liquid in the box 110 and the liquid input part 160 can be quickly drained, which is convenient for the replacement and maintenance of the parts in the immersion box assembly 100.

[0055] Preferably, a detachable drying portion 180 is provided in the overflow chamber 150, and a certain distance exists between the end of the drying portion 180 and the partition 130. The distance between the drying portion 180 and the partition 130 is greater than half the width of the overflow chamber 150. The width of the overflow chamber 150 refers to the distance between the partition 130 away from the wall of the battery cell 120 and the overflow chamber 150. Figure 4 Avoid the distance between the right side of the middle box body 110. Through the above arrangement, since the overflowing immersion liquid flows along the partition 130 away from the wall of the battery cell 120, it will not contact the drying part 180, nor will it affect the performance of the immersion liquid. The drying part 180 includes a drying substance, such as a silica gel desiccant, etc. The drying part 180 can be a porous container. For details, please refer to the prior art and will not be limited here. Through the above arrangement, the immersion liquid in the overflow state has a large surface area, which is convenient for the drying part 180 to absorb the moisture therein, thereby ensuring the insulation effect of the immersion liquid and extending its service life. It should be noted that the drying part 180 is sealed and assembled with the box body 110 to facilitate the replacement of the desiccant therein. The specific sealing assembly structure can refer to the prior art and will not be limited here.

[0056] Specifically, Fig.12 As shown, the energy storage device further includes a liquid output pipeline 166, one end of which is connected to the liquid emptying pipeline 162 and the overflow pipeline 163 respectively, and the other end is connected to the temperature regulating device 400. Through the above arrangement, when maintenance and overhaul are required, the immersion liquid in the immersion tank assembly 100 can be completely emptied, and the discharged immersion liquid can be stored in other storage containers or participate in the temperature regulation of other immersion tank assemblies 100. It should be understood that when the immersion liquid in the immersion tank assembly 100 for maintenance and overhaul is stored in other containers, the corresponding storage container and the valve body for controlling the on-off thereof are also connected to the liquid output pipeline 166, which will not be described in detail here.

[0057] Specifically, a first valve body 1611 is provided on the liquid input pipeline 161, and the first valve body 1611 is used to control the on-off of the liquid input pipeline 161. A second valve body 1621 is provided on the liquid emptying pipeline 162, and the second valve body 1621 is used to control the on-off of the liquid emptying pipeline 162. A third valve body 1661 is provided on the liquid output pipeline 166, and the third valve body 1661 is used to control the on-off of the liquid output pipeline 166. Through the above arrangement, in normal operation, the first valve body 1611 and the third valve body 1661 are opened, and the second valve body 1621 is closed, so that the circulation of the immersion liquid can be realized. When maintenance and overhaul are required, the first valve body 1611 is closed, and the second valve body 1621 and the third valve body 1661 are opened.

[0058] Preferably, the liquid output pipeline 166 is also connected to a waste liquid pipe 510, and the waste liquid pipe 510 is connected to the waste liquid tank 500. A fourth valve body 520 is provided on the waste liquid pipe 510, and the fourth valve body 520 is used to control the on-off of the waste liquid pipe 510. Through the above arrangement, the immersion liquid in the immersion tank assembly 100 can be completely emptied when the immersion liquid is replaced or the battery is thermally runaway, so as to replace a new battery cell 120 or immersion liquid. Specifically, when the immersion liquid is emptied, the first valve body 1611 is closed, the third valve body 1661 is closed, and the second valve body 1621 and the fourth valve body 520 are opened, so that the immersion liquid therein can be emptied.

[0059] Optionally, a pump body 600 is provided on at least one of the liquid input pipeline 161 and the liquid output pipeline 166, and the pump body 600 is used to drive the immersion liquid to circulate, and a pump body 600 (not shown in the drawings) is provided on the waste liquid pipe 510 to discharge the immersion liquid in the immersion tank assembly 100. The provision of the pump body 600 facilitates the speed of circulation or discharge of the immersion liquid.

[0060] In this embodiment, the temperature adjustment device 400 may be a conventional heat exchange device such as a water cooling unit, or may be a structure provided as follows:

[0061] like Figure 6-Figure 11As shown, the temperature regulating device 400 includes: a heat exchange structure 440, a temperature regulating box 410, an external magnet 420, an internal magnet 430, a first magnet 460 and a second magnet 470. The heat exchange structure 440 is used to accommodate the circulating immersion liquid and perform heat exchange and temperature regulation inside the heat exchange structure 440. The heat exchange structure 440 is cylindrical. The temperature regulating box 410 is arranged on the outer circumference of the heat exchange structure 440 and surrounds the heat exchange structure 440 at its center. The external magnet 420 is arranged on the outer sides of the upper and lower ends of the temperature regulating box 410, and the external magnet 420 is close to the The temperature regulating box 410 is arranged at the outer periphery; the internal magnet 430 is arranged on the outer side of the upper and lower ends of the temperature regulating box 410, and the internal magnet 430 is arranged close to the outer periphery of the heat exchange structure 440; the first receiving magnet 460 and the second receiving magnet 470 are arranged inside the temperature regulating box 410; the first receiving magnet 460 and the second receiving magnet 470 can move alternately between the outer peripheral wall of the heat exchange structure 440 and the inner wall of the temperature regulating box 410; the external magnet 420 or the internal magnet 430 can apply a magnetic field to the first receiving magnet 460 and the second receiving magnet 470 in an intermittent manner.

[0062] The first magnet 460 and the second magnet 470 can alternately move between the two positions of fitting the outer wall of the heat exchange structure 440 and fitting the inner wall of the temperature control box 410, which means that when the first magnet 460 moves to the position fitting the outer wall of the heat exchange structure 440, the second magnet 470 is located at the position fitting the inner wall of the temperature control box 410; when the second magnet 470 moves to the position fitting the outer wall of the heat exchange structure 440, the first magnet 460 is located at the position fitting the inner wall of the temperature control box 410. In this embodiment, the external magnet 420 and the internal magnet 430 are electromagnets, which can generate a magnetic field when powered on and eliminate the magnetic field when powered off. The first magnet 460 and the second magnet 470 are magnetocaloric materials, which are magnetized and heated when subjected to a magnetic field and absorb heat when demagnetized. The temperature of the immersion liquid can be regulated by using the above characteristics. For example, when the immersion liquid needs to be cooled, the internal magnet 430 does not work, and the external magnet 420 intermittently applies a magnetic field to the first magnet 460 and the second magnet 470. Specifically, Fig.10 , Fig.11As shown, when the first magnet 460 moves to a position that fits the inner wall of the temperature regulating box 410, the second magnet 470 is located at a position that fits the outer wall of the heat exchange structure 440, and the external magnet 420 applies a magnetic field to the first magnet 460. The first magnet 460 is magnetized and releases heat to the inner wall of the temperature regulating box 410, and the heat is dissipated through the inner wall. After the magnetization is completed, the second magnet 470 moves toward the inner wall of the temperature regulating box 410, and the first magnet 460 moves toward the heat exchange structure 440 (the movement between the two is based on the principle of non-interference). When the second magnet 470 is located at a position that fits the inner wall of the temperature regulating box 410, the external magnet 420 applies a magnetic field to the second magnet 470. When a magnetic field is applied, the second magnet 470 is magnetized to release heat to the inner wall of the temperature control box 410, and the heat is dissipated through the inner wall. At this time, the first magnet 460 is located at a position that fits the outer wall of the heat exchange structure 440. Due to the disappearance of the magnetic field, the first magnet 460 becomes cold and absorbs heat, and the heat in the immersion liquid is absorbed through the heat exchange structure 440, thereby realizing a refrigeration cycle; when heating is required, the external magnet 420 does not work, and the internal magnet 430 intermittently applies a magnetic field to the first magnet 460 and the second magnet 470. The specific operation method and the movement method of related components can be reasonably deduced through the refrigeration cycle, thereby completing the heating cycle of the immersion liquid, which will not be repeated here. The above-mentioned arrangement can realize rapid cooling or heating of the immersion liquid, with high heat exchange efficiency, more energy saving, safety, environmental protection, and easy miniaturization. Preferably, a heat sink (not shown in the drawings) corresponding to the first magnet 460 and the second magnet 470 is provided on the inner wall of the temperature regulating box 410, and the heat sink is connected to the heat dissipation structure outside the temperature regulating box 410. The heat dissipation structure can be a conventional air-cooled, water-cooled or wind-cooled structure, which is not limited here. This arrangement can significantly improve the heat dissipation effect, thereby achieving smooth heat discharge. Optionally, the magnetocaloric material can be a La(FeSi)13 type magnetocaloric material, or other known magnetocaloric materials, which are not limited here.

[0063] Furthermore, the first magnet 460 and the second magnet 470 respectively include an equal number of sub-magnets, and the sub-magnets in the first magnet 460 and the second magnet 470 are arranged at intervals in the outer circumferential direction of the heat exchange structure 440. When the first magnet 460 or the second magnet 470 is attached to the outer circumferential wall of the heat exchange structure 440, the sub-magnets therein can be attached to the circumference of the heat exchange structure 440. Through the above arrangement, the overall heat exchange of the outer circumferential wall of the heat exchange structure 440 can be achieved, and the heat exchange efficiency can be significantly improved. Moreover, since the first magnet 460 and the second magnet 470 are alternately attached to the outer circumferential wall of the heat exchange structure 440, the interval time between movement and magnetization and demagnetization can be reduced, thereby improving the heat exchange efficiency.

[0064] In this embodiment, if Fig.10 , Fig.11 As shown, a slide rail 480 and a driving structure (not shown in the drawings) corresponding to the sub-receiving magnets are provided inside the temperature control box 410, and the sub-receiving magnets are slidably connected to the slide rail 480 in a one-to-one correspondence, and are used to move along the slide rail 480 under the drive of the driving structure. It should be noted that the driving structure can be a conventional structure in the prior art such as a motor-driven screw structure, a belt structure, etc., which is not limited here.

[0065] As one of the preferred embodiments, a plurality of fins 450 are provided on the outer peripheral wall of the temperature regulating box 410 , and the fins 450 are used to improve the heat dissipation effect of the temperature regulating box 410 .

[0066] Specifically, the heat exchange structure 440 includes a liquid inlet 441, a liquid outlet 442 and a heat exchange chamber 443. The liquid inlet 441 and the liquid outlet 442 are respectively connected to the heat exchange chamber 443. The liquid inlet 441 is connected to the liquid output pipeline 166, and the liquid outlet 442 is connected to the liquid input pipeline 161. Through the above arrangement, the immersion liquid passing through the immersion tank assembly 100 enters the heat exchange chamber 443 through the liquid inlet 441, exchanges heat in the heat exchange chamber 443 for temperature adjustment, and then flows into the immersion tank assembly 100 through the liquid outlet 442, so as to realize the circulation of the immersion liquid, and significantly improve the temperature control effect of the battery unit 120. Preferably, a stirring device is also provided in the heat exchange chamber 443, and the stirring device is used to stir the immersion liquid in the heat exchange chamber 443 to destroy the temperature boundary layer between the heat exchange chamber 443 and the immersion liquid, thereby improving its heat exchange effect. The stirring device may refer to the structure of the liquid stirring device in the cylinder in the prior art, and will not be limited here.

[0067] On this basis, this embodiment also proposes a temperature control method for an energy storage system, comprising the following steps:

[0068] Step S1: Obtain the temperature of the battery cell and determine the required temperature control method. If the temperature needs to be raised, execute step S2; if the temperature needs to be lowered, execute step S5;

[0069] Step S2: Start the temperature regulating device to raise the temperature of the immersion liquid. When the temperature rises to the first target temperature T1, connect the liquid input pipeline to supply liquid to the immersion tank assembly, and then execute step S3:

[0070] Step S3: monitoring the temperature of the battery cell. When the temperature reaches the second target temperature T2, the energy storage system starts to operate, the temperature regulating device stops supplying heat, and stops delivering the immersion liquid, and then executing step S4;

[0071] Step S4: When it is detected that the battery cell temperature exceeds the third target temperature T3, step S5 is executed;

[0072] Step S5: starting the temperature regulating device to cool the immersion liquid, and connecting the liquid input pipeline to supply liquid to the immersion tank assembly. When the battery cell temperature is detected to be lower than the fourth target temperature T4, the energy storage system starts to operate and executes step S6;

[0073] Step S6: stably operate the temperature regulating device to control the immersion liquid supply temperature within the first preset temperature range T5.

[0074] Wherein step S2 comprises:

[0075] Step S21: starting the temperature adjustment device to move the first magnetized body to a position in contact with the outer peripheral wall of the heat exchange structure;

[0076] Step S22: the internally added magnet is energized to magnetize the first magnetized body, and the magnetized first magnetized body releases heat and exchanges heat with the immersion liquid in the heat exchange structure to increase its temperature;

[0077] Step S23: After the first magnet is magnetized for a first time period t1, the first magnet and the second magnet are switched, and the internal magnet magnetizes the second magnet. After magnetization, the second magnet is magnetized and releases heat, and exchanges heat with the immersion liquid in the heat exchange structure to increase its temperature.

[0078] Step S24: After the second receiving magnet is magnetized for the first time t1, the second magnet switches positions with the first receiving magnet, and the internal magnet magnetizes the first receiving magnet. After magnetization, the first receiving magnet is magnetized and releases heat, and exchanges heat with the immersion liquid in the heat exchange structure to increase its temperature.

[0079] Step S25: Repeat steps S23 and S24 until the immersion liquid is heated to the first target temperature T1, and then execute step S26;

[0080] Step S26: Connect the liquid input pipeline to supply liquid to the immersion tank assembly.

[0081] It should be noted that when the magnetocaloric material is magnetized, the magnetic moment of the material is orderly arranged along the external magnetic field, resulting in a decrease in magnetic entropy and heat release from the material; when demagnetized, the magnetic moment changes from ordered to disordered, the magnetic entropy increases, and the material absorbs heat. Therefore, the magnetization heat absorption and demagnetization heat release process of the magnetocaloric material is carried out in stages. After a certain period of magnetization, the magnetic moment needs to be changed by demagnetization. Therefore, the first duration t1 is a preset time data, which will be affected by multiple factors such as the thermal conductivity of different materials, the size of the components, the area of ​​the bonding surface, and the time for the magnetic moment to be orderly arranged. It is no longer limited here. Taking individual numbers as an example, t1 can be 3 minutes. The first target temperature T1 is a preset value, and its value range is between 5°C and 10°C, preferably 8°C. It should be understood that energy storage systems such as energy storage containers can be installed in locations with relatively harsh environments. Therefore, the installation environment may experience extremely cold weather, such as temperatures below -30°C or even -40°C. In this case, the battery unit 120 cannot operate normally, and it is necessary to use immersion liquid to preheat it before starting. After it reaches a temperature range where it can operate relatively normally, it can be started and operated, which can effectively ensure the safety and stability of the battery unit 120.

[0082] In step S3, the value range of T2 is 10°C to 20°C, preferably 15°C. Within this temperature range, the battery cell 120 can start and operate normally, and the battery cell 120 will continue to generate heat during operation. During this process, the temperature of the immersion liquid will gradually increase, so that the battery cell 120 can be maintained within the normal operating temperature range.

[0083] In step S4, the value range of T3 is 35°C-40°C, preferably 35°C. At this temperature, the battery cell 120 can still operate normally, but as the operating time increases, the non-circulating immersion liquid can no longer maintain the temperature stability of the battery cell 120. At this time, the temperature regulating device 400 is required to cool the immersion liquid in order to maintain the temperature stability of the battery cell 120.

[0084] Step S5 includes:

[0085] Step S51: start the temperature adjustment device to move the first magnet to a position in contact with the inner wall of the temperature adjustment box;

[0086] Step S52: the external magnet is energized to magnetize the first magnetized body, and the magnetized first magnetized body releases heat through the side wall of the temperature regulating box;

[0087] Step S53: After the first magnet is magnetized for the first time t1, the first magnet and the second magnet are switched, and the second magnet is magnetized by an external magnet. After magnetization, the second magnet is magnetized and releases heat, which is dissipated through the side wall of the temperature control box. At this time, the first magnet is attached to the outer peripheral wall of the heat exchange structure and absorbs heat from the immersion liquid inside the heat exchange structure to cool it down.

[0088] Step S54: After the second magnet is magnetized for the first time t1, the second magnet switches positions with the first magnet, and the first magnet is magnetized by an external magnet. After magnetization, the first magnet is magnetized and releases heat, which is dissipated through the side wall of the temperature control box. At this time, the second magnet fits the outer peripheral wall of the heat exchange structure and absorbs heat from the immersion liquid inside the heat exchange structure, so that the temperature is reduced.

[0089] Step S55: connecting the liquid input pipeline to supply liquid to the immersion tank assembly;

[0090] Step S56: When it is detected that the battery cell temperature is lower than the fourth target temperature T4, the energy storage system starts to operate.

[0091] After the temperature of the immersion liquid is lowered by the temperature regulating device 400, it can be directly supplied to the immersion tank assembly 100, thereby instantly lowering the operating temperature of the battery cell 120. In nature, under normal circumstances, the temperature will not exceed the temperature range of normal operation of the battery cell 120. When an extreme situation occurs and exceeds its normal operating range, the temperature regulating device 400 is first started for refrigeration, and the immersion liquid is transported to the immersion tank assembly 100. When the temperature of the battery cell 120 is lowered to a suitable temperature, the operation is started again. The operating safety of the battery cell 120 is guaranteed, and it also ensures that it has the best operating performance and service life. Among them, the fourth target temperature T4 is a preset value, and its value range is 35°C-45°C, preferably 40°C. This setting can prevent the battery cell 120 from operating at high temperature and keep it within a better operating temperature.

[0092] In step S6, the value range of the first preset temperature range T5 is between 20°C and 30°C. Preferably, it is between 20°C and 25°C. The above temperature range can be achieved by the staged operation of the temperature adjustment device 400, which is similar to the variable frequency operation of the air conditioner, and will not be repeated here. Through the above setting, the operating range of the battery cell can be controlled between 22°C and 35°C, so that it is in the optimal operating temperature range, ensuring its performance and service life.

[0093] Furthermore, a fifth valve body 1631 is provided on the overflow pipe 163, and the fifth valve body 1631 is used to control the on-off of the overflow pipe 163. It should be understood that under normal operating conditions, there is no need to provide a valve body on the overflow pipe 163. However, when the battery cell 120 is in thermal runaway, the battery solution is likely to leak. At this time, the overflow pipe 163 is likely to transport the immersion liquid mixed with the battery solution of the battery cell 120 to the immersion liquid circulation system. The provision of the fifth valve body 1631 facilitates intermittent drainage of the overflow chamber 150. When the immersion liquid overflowing to the overflow chamber 150 reaches a certain liquid level, the fifth valve body 1631 is opened to discharge the immersion liquid in the overflow chamber 150. When thermal runaway of the battery cell 120 is detected, the immersion liquid containing the battery solution will not be mixed into the immersion liquid of other normally operating immersion tank assemblies 100 at the first time. At this time, the immersion liquid in the immersion tank assembly 100 where the battery solution has leaked can be completely discharged through the coordinated control of the first valve body 1611, the second valve body 1621, the third valve body 1661, the fourth valve body 520, and the fifth valve body 1631, thereby effectively reducing the safety hazards and immersion liquid losses caused by thermal runaway.

[0094] It should be understood that the energy storage system using immersion cooling can reduce the probability of thermal runaway of the battery cell 120 and the risks it brings to a certain extent, and basically will not catch fire. However, when thermal runaway occurs in the battery cell 120, in addition to the leakage of battery solution, a large amount of gas will be generated, causing the air pressure inside the box 110 to rise rapidly, posing a considerable safety hazard.

[0095] In order to further solve the above problems, an immersion energy storage system is further proposed in the embodiments of the present application, such as Figure 5 As shown, including:

[0096] As mentioned above, the energy storage device:

[0097] Furthermore, a pressure relief plate 190 is provided at the upper corner of the box body 110 away from the partition 130. The pressure relief plate 190 is rotatably connected to the top cover or the side wall of the box body 110. The pressure relief plate 190 can be opened to discharge the gas in the box body 110, and can also be closed to seal the box body 110.

[0098] A pressure relief assembly 200, wherein the pressure relief assembly 200 is disposed on the upper side of the box body 110 and is sealed and connected to the box body 110, a pressure relief channel 210 is formed between the pressure relief assembly 200 and the top of the box body 110, and at least one end of the pressure relief channel 210 is connected to the housing 300 of the energy storage system;

[0099] The housing 300 has a ventilation portion 310 disposed at a position of the housing 300 corresponding to the pressure relief assembly 200 .

[0100] Through the above arrangement, when the battery unit 120 in the immersion tank assembly 100 has thermal runaway, the pressure relief plate 190 can be opened to transport the gas generated by the thermal runaway to the pressure relief channel 210, and then discharged through the ventilation part 310, thereby effectively reducing the air pressure in the immersion tank assembly 100, and further reducing the risk of thermal runaway battery units 120. It should be understood that one pressure relief assembly 200 can be connected to more than one immersion tank assembly 100, so as to achieve the control of thermal runaway of more than one immersion tank assembly 100. It should be understood that the height of the plane where the lower end of the pressure relief plate 190 is connected is higher than the height of the top of the partition 130, which is used to prevent the immersion liquid from leaking from the connection position of the pressure relief plate 190.

[0101] As one of the preferred embodiments, the angle between the pressure relief plate 190 and the side wall of the box body 110 is α, and the value of α is 20° to 40°, preferably, α is 30°. Through the above arrangement, the pressure relief plate 190 can be opened with a small force when it is rotatably connected to the side wall of the box body 110, and the flow of gas in the pressure relief channel 210 will not be affected.

[0102] In this embodiment, a barometer (not shown in the drawings) is provided above the immersion chamber 140, and the barometer is used to detect the pressure of the air above the immersion chamber 140. Preferably, the barometer is controlled in linkage with the pressure relief plate 190, and is used to open the pressure relief plate 190 to relieve pressure when the pressure rises to a certain level. In addition, the barometer may not be provided, and the purpose of pressure relief can also be achieved by providing the pressure relief plate 190 to be pushed open by gas when subjected to a certain air pressure.

[0103] As one of the preferred embodiments, a poison-proof structure 230 is provided at a position of the pressure relief channel 210 near the shell 300, and the poison-proof structure 230 is used to absorb the toxic gas released when the battery cell 120 is in thermal runaway. It should be understood that a large amount of toxic gas will be released when the battery cell 120 is in thermal runaway, and direct discharge of it will cause serious damage to the environment. Through the provision of the poison-proof structure 230, some of the toxic gases can be removed to reduce the damage caused. It should be noted that the poison-proof structure 230 can adopt an existing porous structure, in which activated carbon, chemical adsorbents such as copper sulfate and other materials impregnated with activated carbon are provided, so as to reduce the content of toxic gas when the gas passes through. As one of the preferred embodiments, there are more than two poison-proof structures 230, and the air holes on the more than two poison-proof structures 230 gradually increase from the direction close to the shell 300 to the direction close to the immersion tank assembly 100. This setting can achieve the step-by-step removal of toxic gases, thereby significantly improving the removal effect and reducing the pollution of the environment by the gas emitted by thermal runaway.

[0104] In another optional embodiment, an inclined waterproof plate 220 is provided on the bottom plate of the pressure relief channel 210 inside the shell 300, the waterproof plate 220 is provided between the shell 300 and the anti-toxic structure 230, and the waterproof plate 220 is gradually arranged away from the shell 300 from bottom to top, and a drainage portion 320 is provided at the connection position between the shell 300 and the bottom of the pressure relief channel 210, and the drainage portion 320 is used to drain the water blocked by the waterproof plate 220. It should be understood that in rainy and snowy weather, rain and snow water can easily enter the pressure relief channel 210 through the ventilation portion 310, affecting the normal operation of the immersion tank assembly 100, and the provision of the waterproof plate 220 can effectively block the moisture entering the pressure relief channel 210, ensuring the normal operation of the energy storage system.

[0105] Specifically, the waterproof plate 220 includes a water guide slope 221 and a waterproof main board 222. The water guide slope 221 is arranged between the housing 300 and the waterproof main board 222, and the water guide slope 221 is gradually raised from one end close to the housing 300 to one end connected to the waterproof main board 222, and the waterproof main board 222 is gradually inclined away from the housing 300 from bottom to top. This arrangement facilitates the rapid discharge of water entering the pressure relief channel 210 to prevent it from accumulating in the pressure relief channel 210.

[0106] Preferably, there is a certain distance between the upper end of the waterproof main board 222 and the upper inner wall surface of the pressure relief channel 210. This arrangement facilitates airflow to flow through the upper side of the waterproof main board 222.

[0107] In one of the preferred embodiments, a one-way movable plate 223 is provided on the waterproof main board 222, and the one-way movable plate 223 is rotatably connected to the waterproof main board 222, and can be rotated and opened in the direction of the housing 300 under a certain air pressure to connect the spaces on both sides of the waterproof main board 222. It should be understood that when the battery unit 120 has thermal runaway, it generates a large amount of gas, which causes the air pressure to rise rapidly. After the gas is discharged into the pressure relief channel 210, if the gas is allowed to flow out from the upper end of the waterproof main board 222, its flow rate is limited, which will cause the gas pressure in the pressure relief channel 210 to rise rapidly, and there is a certain risk. The one-way movable plate 223 can be rotated and opened when the pressure is high, so that the gas inside the waterproof main board 222 can flow out directly, significantly increasing the air outlet speed and avoiding pressure increase.

[0108] As one of the optional embodiments, the angle between the waterproof main board 222 and the bottom plate of the pressure relief channel 210 is denoted as β, and the value range of β is 50°-70°. Preferably, the value of β is 60°. Specifically, the upper end of the one-way movable plate 223 is rotatably connected to the waterproof main board 222, and a step surface is provided on the waterproof main board 222 near the lower end of the one-way movable plate 223, and the step surface abuts against the one-way movable plate 223 to prevent it from rotating in the direction of the immersion tank assembly 100. Through the above arrangement, the one-way movable plate 223 can be pushed by a relatively small air pressure, so that it can effectively relieve pressure, reducing the risk of thermal runaway of the battery cell 120.

[0109] On this basis, this embodiment also provides a method for controlling thermal runaway of a battery cell, comprising the following steps:

[0110] Step ST1: Detecting the temperature rise rate v1 of the battery unit in the energy storage system and the air pressure value P1 on the upper side of the immersion chamber;

[0111] Step ST2: compare the temperature rise rate v1 of the battery cell with the preset temperature rise rate v2, and compare the air pressure value P1 on the upper side of the immersion chamber with the preset pressure threshold value P2. When the comparison result satisfies at least one of v1≥v2 and P1≥P2, it is determined that the current battery cell has thermal runaway, an alarm signal is issued, and step ST3 is executed; when the comparison result satisfies v1<v2 and P1<P2, it is determined that the current battery cell is operating normally, and the process returns to step ST1;

[0112] Step ST3: Cut off the power supply of the current battery cell, open the pressure relief plate in the immersion tank assembly corresponding to the current battery cell and the one-way movable plate in the corresponding pressure relief channel, and close the liquid input pipeline, overflow pipeline and liquid output pipeline of the immersion tank assembly corresponding to the current battery cell; the specific operation method of closing the pipeline is to close the first valve body 1611, the fifth valve body 1631 and the third valve body 1661, the second valve body 1621 and the fourth valve body 520 are normally closed valve bodies, which are kept in the closed state; opening the pressure relief plate 190 and the one-way movable plate 223 can automatically lift them up by internal pressure or use the corresponding control module to control their opening. The specific structure can refer to the prior art and is no longer limited here.

[0113] Step ST4: continuously detecting the temperature change of the battery cell that has thermal runaway and the gas pressure value in the immersion tank assembly where the battery cell is located;

[0114] Step ST5: When the temperature of the battery cell that has thermal runaway drops below the first preset temperature threshold Q1, and the air pressure in the immersion tank assembly where the battery cell is located is less than the preset pressure threshold P2, step ST6 is executed:

[0115] Step ST6: connect the overflow pipeline, the liquid drain pipeline and the waste liquid pipe to discharge the immersion liquid inside the immersion tank assembly where the thermal runaway battery unit is located into the waste liquid tank. The specific operation method is to open the second valve body 1621, the fourth valve body 520 and the fifth valve body 1631, and keep the first valve body 1611 and the third valve body 1661 in the closed state. Since the pressure relief plate 190 is also in the open state at this time, the immersion liquid in the immersion tank assembly 100 can be discharged into the waste liquid tank 500 as soon as possible.

[0116] It should be understood that when thermal runaway occurs in the battery cell 120, its temperature will rise rapidly and a large amount of gas will be generated, causing the pressure in the immersion chamber 140 to rise significantly. Any of the above two points can be used to determine whether thermal runaway occurs in the battery cell 120. When thermal runaway occurs in the battery cell 120, the battery solution therein is likely to leak into the immersion liquid, causing contamination of the immersion liquid. At this time, if the immersion liquid is still involved in the circulation, the immersion liquid in the entire energy storage system will be contaminated, seriously affecting the normal operation of the energy storage system. In the present application, the intermittent discharge of the overflow immersion liquid is realized by the setting of the fifth valve body 1631. When the liquid level in the overflow chamber 150 reaches the first preset height H1, the fifth valve body 1631 is started to discharge the liquid. The first preset height H1 is a height lower than the lower end surface of the drying portion 180 by a certain distance. Optionally, the difference between the height of the lower end surface of the drying portion 180 and the first preset height H1 is 10-20 mm. On the one hand, this setting can store a certain amount of immersion liquid in the overflow chamber 150, so that the immersion liquid will not flow into the circulating liquid in the first time. In the circulation system, when the thermal runaway battery solution leaks, the immersion liquid mixed with the battery solution can be prevented from flowing into the circulation system to a certain extent, thereby ensuring the purity of the immersion liquid in the energy storage system. In addition, when the temperature of the battery cell 120 with thermal runaway drops to a certain level and the air pressure in the box 110 also drops to a certain level, it indicates that the thermal runaway of the battery cell 120 has been effectively alleviated. At this time, the immersion liquid in the immersion box assembly 100 can be completely removed so that the operator who receives the alarm can perform corresponding follow-up processing.

[0117] As one of the optional embodiments, the preset temperature rise rate v2 is between 1.8°C / s and 2.2°C / s, preferably 2°C / s; the preset pressure threshold P2 is between 118KPa and 122KPa, preferably 120KPa. Through the above preset conditions, it is possible to timely determine whether the battery unit 120 has thermal runaway, so as to take corresponding measures to reduce its risk in time.

[0118] In one embodiment, the alarm signal includes one or a combination of sound, vision, vibration, and remote monitoring platform notification. The alarm signal can promptly notify the operator to take corresponding measures on the battery cell 120 in thermal runaway to avoid risk escalation.

[0119] In step S5, the value of the first preset temperature threshold Q1 is between 50°C and 60°C, preferably 55°C. It should be understood that when thermal runaway occurs, there is a large amount of immersion liquid with a relatively low temperature in the immersion chamber 140. Although it is disconnected from the immersion liquid circulating in the energy storage system, it can still prevent the battery unit 120 from catching fire and exchange heat with the battery unit 120 in thermal runaway, thereby causing its temperature to drop rapidly. When its temperature drops below the first preset temperature threshold Q1, it indicates that the process of thermal runaway has stabilized and further risks have been avoided. At this time, the immersion liquid in the immersion tank assembly 100 can be discharged to facilitate subsequent processing by the operator.

[0120] This embodiment further provides a thermal runaway control device, which is used to execute the temperature control method as described above, and the thermal runaway control device at least includes:

[0121] A pressure detection unit for detecting the air pressure in each immersion tank assembly;

[0122] A temperature detection unit, used to detect the temperature of each battery cell;

[0123] A judgment unit, used to judge whether the temperature rise rate and the air pressure meet the judgment conditions of thermal runaway;

[0124] A control unit is used to control the execution of a corresponding thermal runaway control method.

[0125] In the current immersed energy storage system, in addition to the risk of thermal runaway of the battery unit 120, there is also the risk of leakage of the immersion fluid. Leakage of the immersion fluid is prone to system failure, environmental pollution, health hazards, ecological problems, and fire safety, etc., and strict management and technical measures are needed to reduce the corresponding risks.

[0126] In order to effectively deal with the risk of immersion liquid leakage in the submerged energy storage system, based on the above structure, this embodiment also provides an immersion liquid leakage detection method for the submerged energy storage system, which is used for the immersion tank assembly 100 as described above, and includes the following steps:

[0127] Step 1: When the energy storage system is running, the submerged tank assembly is operated in a rotating manner, wherein the submerged tank assembly is operated in a rotating manner, which means that when the energy storage system is running, all battery cells in at least one of all the submerged tank assemblies contained therein do not participate in the operation;

[0128] Step 2: Close the liquid input pipeline of the immersion tank assembly in the rest state;

[0129] Step 3: After a first preset time has passed, the liquid level of the immersion liquid in the immersion chamber is detected, and the actual liquid level of the immersion chamber at this time is recorded as a first liquid level L1;

[0130] Step 4: Compare the first liquid level L1 with the height D of the partition. When L1≥D, execute step 5; when L1<D, execute step 6;

[0131] Step 5: It is determined that there is no immersion liquid leakage in the current immersion chamber, and the liquid input pipeline corresponding to the immersion tank assembly is opened. When the rotation is over, the immersion tank assembly participates in the operation of the energy storage system normally, and the immersion tank assembly is no longer tested for leakage for a period of time;

[0132] Step 6: Determine whether there is immersion liquid leakage in the current immersion chamber, keep the immersion tank components in rotation and the liquid input pipeline closed, isolate the current immersion tank component from the energy storage system, and send out a leakage alarm signal.

[0133] In this embodiment, by setting the partition 130, the liquid level in all the immersion tank assemblies 100 is in a stable state. Therefore, when leakage detection is required, the height of the partition 130 naturally becomes the corresponding target liquid level. If the liquid level after stopping for a period of time is lower than the liquid level of the partition 130, it indicates that there is leakage in the immersion chamber 140, and corresponding processing operations need to be performed. In this case, there is no need to detect the initial liquid level in the immersion chamber 140, and the immersion liquid in all the immersion chambers 140 is at the same liquid level, which significantly reduces the number of corresponding liquid level signal detections in the energy storage system and the number of data processing, so that it can be simply and conveniently detected whether there is leakage in the immersion tank assembly 100, so as to process it more timely and accurately. It should be noted that when the fifth valve body 1631 is not provided in the overflow pipeline, or the fifth valve body 1631 is in a normally open state, no immersion liquid will be accumulated therein, so whether it leaks has little effect on the immersion tank assembly 100, and it can be monitored, which significantly reduces the workload of leakage detection. Through the above settings, leakage detection can be performed without affecting the normal operation of the energy storage system, so that the operator can take corresponding measures in time, reducing the risk of leakage in the energy storage system. At the same time, the rotation also helps to balance the charge state of the battery unit 120 in the energy storage system, reducing the risk of overcharging or over-discharging the battery unit 120. The value range of the first preset time is 20s-40s, preferably 30s.

[0134] Wherein, step 1 comprises:

[0135] Step 11: Determine the current operating state of the energy storage system. If it is in the charging state, execute step 12; if it is in the discharging state, execute step 13;

[0136] Step 12: Compare the SOC values ​​of the battery cells in each immersion tank assembly, and take turns to rest according to the SOC values ​​from high to low;

[0137] Step 13: Compare the SOC values ​​of the battery cells in each immersion tank assembly, and take turns to rest according to the SOC value from low to high.

[0138] Through the above settings, when charging, the battery cells 120 in the immersion tank assembly 100 with the highest SOC value are rested first, so that the other battery cells 120 can quickly shorten the power gap with the battery cell 120 with the highest SOC value, thereby helping to achieve the balance of the charge of the battery cells 120 during charging, avoiding overcharging, and reducing the risk of thermal runaway; when discharging, the battery cells 120 in the immersion tank assembly 100 with the lowest SOC are rested first, thereby helping to achieve the balance of the charge of the battery cells 120 during discharging, avoiding over-discharge, and ensuring the service life of the battery cells 120. It should be noted that the SOC value of the battery cells 120 in the immersion tank assembly 100 described in this embodiment is the mean or median value of the SOC of the battery cells 120 that can operate normally. The SOC difference of the battery cells 120 in the same immersion tank assembly 100 can be controlled by other existing balancing means, which will not be limited here. The detection of the SOC value can refer to the existing technology in the energy storage system, which will not be repeated here. By setting the above control method, the operation of the energy storage system and the leakage detection can be carried out synchronously, and the balanced control of the charge state of the battery cells 120 in the immersion tank assembly 100 can also be achieved.

[0139] Specifically, step 12 also includes:

[0140] Step 121: Compare the SOC of the battery cells in the immersion tank assembly that has completed the rotation and has not been leaked with the current SOC of the battery cells in other immersion tank assemblies, and continue to rotate the charging according to the SOC sorting from high to low.

[0141] Step 13 also includes:

[0142] Step 131: Compare the SOC values ​​of the battery cells in the immersion tank assembly that has completed the rest and has not leaked with the current SOCs of the battery cells in other immersion tank assemblies, and continue to perform rest discharge in descending order according to the SOC.

[0143] Through the above arrangement, while detecting whether there is leakage, the difference in the charge state of the battery cells 120 between different immersion tank assemblies 100 can be significantly reduced, thereby reducing the risk of thermal runaway or service life damage caused by overcharging or overdischarging of the battery cells 120.

[0144] As one of the optional embodiments, in step 1, the rest time of each immersion tank assembly is obtained according to formula (1):

[0145]

[0146] Among them, Ti is the rotation time of the current immersion tank assembly, Tb is the basic rotation duration, Tc is the rotation duration coefficient, ΔSOC is the difference between the SOC value of the battery cell in the current immersion tank assembly and the maximum or minimum SOC value in the energy storage system. Specifically, when charging, ΔSOC is the difference between the SOC value of the battery cell in the current immersion tank assembly and the minimum SOC value in the energy storage system; when discharging, ΔSOC is the difference between the maximum SOC value in the energy storage system and the SOC value of the battery cell in the current immersion tank assembly, R is the charge and discharge rate, and Tb and Tc are preset values.

[0147] Through the above settings, the rotation time of the immersion tank assembly 100 with different SOC values ​​is different. When charging, the rotation time of the immersion tank assembly 100 with a larger SOC value is longer, and when discharging, the rotation time of the immersion tank assembly 100 with a smaller SOC value is longer, so that the problem of uneven charge state of the battery cells 120 in the immersion tank assembly 100 can be improved to a certain extent. It should be understood that the fundamental purpose of this embodiment is to detect whether there is leakage in the energy storage system. In this case, if the rotation time is too long, it will lead to the inability to effectively detect all the immersion tank assemblies 100. In this case, by pre-setting Tb and Tc, the rotation time of each immersion tank assembly 100 can be effectively controlled, thereby ensuring the smooth progress of leakage detection. Among them, Tb and Tc can be equal or not. Taking one of the discharge states as an example, Tb and Tc are preset to 60 seconds, ΔSOC is 0.2, and the discharge rate is 0.5C. According to calculation, the rotation time of the immersion tank assembly 100 is 90 seconds. Through the above settings, the rest time of the immersion tank assembly 100 is limited to between 60 seconds and 120 seconds, which ensures the smooth progress of the immersion liquid leakage detection. While the immersion liquid leakage detection is being performed, the charge state of the battery cells 120 in the immersion tank assembly 100 is balanced to a certain extent. Specifically, the operator can preset Tb and Tc according to the type of battery cells 120, the number of immersion tank assemblies 100 and other related information, which will not be limited here. It should be understood that R represents the discharge rate in the discharge state and the charge rate in the charge state.

[0148] Optionally, for the submerged tank assembly determined not to have leakage, Tb in formula (1) is recorded as 0. This setting can reduce the rotation time of the submerged tank assembly 100 determined not to have leakage, thereby improving the detection efficiency of the energy storage system leakage.

[0149] Furthermore, a second box body 700 is sealed on the outer side of the box body 110, the immersion box assembly 100 is partially arranged in the second box body 700, and a liquid receiving pan 710 is arranged at the inner bottom end of the second box body 700. The liquid receiving pan 710 is used to collect liquid leaked when the immersion liquid leaks and discharge it to the waste liquid tank 500.

[0150] In this embodiment, the second box body 700 is sealed with the box body 110. Even if the immersion liquid leaks, it will directly flow into the waste liquid tank 500 and will not leak into the external environment, which significantly improves the safety of the energy storage system. It should be understood that in order to facilitate the assembly of the aforementioned pressure relief assembly 200, the connection position between the top cover of the second box body 700 and the box body 110 is located on the lower side of the pressure relief assembly 200. In this case, the pressure relief plate 190 will also be located on the upper side of the second box body 700. In addition, the setting of the partition 130 facilitates stabilizing the liquid level, so that the reference liquid level during leakage detection remains consistent, thereby making it easier to distinguish the immersion box assembly 100 that has leaked.

[0151] As one of the optional embodiments, the position where the top cover of the second box body 700 is connected to the box body 110 is higher than the top of the partition 130. It should be understood that due to the setting of the partition 130, during normal operation, the immersion liquid level in the immersion chamber 140 will not exceed the top of the partition 130. Therefore, even if the immersion liquid leaks, the leakage point will not be higher than the top of the partition 130. Therefore, through the above setting, the second box body 700 can completely cover all possible leakage points, and then the leaked immersion liquid is transferred to the waste liquid tank 500 through the liquid receiving tray 710, completing the closed transfer of the leaked immersion liquid, which significantly reduces the risk of immersion liquid leakage.

[0152] As one of the optional embodiments, the liquid receiving pan 710 includes a concave groove 711 arranged at the center, the bottom of the immersion tank assembly 100 is fitted and embedded in the concave groove 711, a step portion 712 is formed on the periphery of the concave groove 711, and a step is formed between the step portion 712 and the periphery of the liquid receiving pan 710 to form a liquid receiving space, and a drain pipe 713 is also arranged on the liquid receiving pan 710 to pass through its periphery and the second box body 700, and the drain pipe 713 is connected to the waste liquid tank 500. Through the above arrangement, it is convenient to match the immersion tank assembly 100 with the second box body 700 to form a pre-assembled accessory, and due to the arrangement of the concave groove 711, the immersion tank assembly 100 is limited, which significantly improves its stability in assembly.

[0153] Optionally, the liquid receiving tray 710 is made of an insulating material that can isolate the immersion liquid, such as foam, ceramic, polyurethane, etc. The above materials are all insulating materials and can effectively prevent the penetration of the immersion liquid, so that the leaked immersion liquid can be collected and discharged. In addition, since the bottom of the immersion box assembly 100 is embedded in the recessed groove 711, the bottom of the recessed groove 711 is a bottom sealing structure and does not have a leakage space, thereby effectively preventing the risk of leakage at the bottom of the immersion box assembly 100.

[0154] On this basis, the following steps are included after step 6:

[0155] Step 7: Detect and determine the height of the liquid leakage within the second preset time, calculate the liquid leakage rate, and then execute step 7;

[0156] Step 8: Compare the leakage rate with the drainage rate of the drain pipe.

[0157] When the leakage rate is greater than the drainage rate, the liquid draining pipeline connected to the immersion chamber is opened to assist in draining the liquid to the waste liquid tank;

[0158] When the leakage rate is less than the drainage rate, the immersion tank components are kept in rotation and the liquid input pipeline is kept closed.

[0159] It should be understood that when the leakage rate is high, it is easy to quickly fill the liquid receiving tray 710 and the second box body 700, which may cause further leakage. At this time, draining the immersion liquid in the immersion chamber 140 as quickly as possible can minimize the risk of immersion liquid leakage. When the leakage rate is low, the leakage cannot fill the liquid receiving tray 710, and will not cause damage to the second box body 700 and its external components. The current state can be maintained while waiting for the operator to perform subsequent processing. It should be understood that calculating the leakage rate based on the leakage height is a conventional calculation in the prior art and will not be repeated here. The value range of the second preset time is 10s-30s, preferably 20s.

[0160] It should be noted that the leakage alarm signal includes one or a combination of sound, vision, vibration, and remote monitoring platform notification. The leakage alarm signal can promptly notify the operator to take corresponding measures on the immersion tank assembly 100 where leakage occurs, thereby avoiding risk escalation.

[0161] This embodiment also discloses an energy storage system, which includes the above-mentioned immersion energy storage device or one or more of the above-mentioned temperature control method, heat loss control method and immersion liquid leakage detection method. The energy storage system can be an energy storage container, energy storage cabinet, etc., which is not limited here.

[0162] It should be noted that the corresponding data detections such as the temperature detection unit, pressure detection, and liquid level detection described in this embodiment all require corresponding detection units to be set in corresponding positions or spaces, and the required setting methods or means are conventional technical means in the field and will not be elaborated here.

[0163] The energy storage system also includes other conventional components such as BMS, and the details can be referred to the prior art and will not be described here.

[0164] Although the present invention is disclosed as above, the present invention is not limited thereto. In the description of this specification, the description of reference terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, so the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. An immersion energy storage device, characterized in that: include: An immersion box assembly (100) comprises a box body (110) and a battery unit (120), wherein the battery unit (120) is arranged in the box body (110), a circulating immersion liquid is arranged in the box body (110), and the battery unit (120) is completely immersed in the immersion liquid; a temperature regulating device (400), the temperature regulating device (400) being connected to the immersion tank assembly (100) and being used for regulating the temperature of the immersion liquid circulating therein; A partition (130) is provided inside the box (110), and the partition (130) is used to separate the chamber inside the box (110) into an immersion chamber (140) and an overflow chamber (150). A certain distance exists between the top of the partition (130) and the inner wall of the top plate of the box (110), so that the immersion chamber (140) and the overflow chamber (150) are connected at the top of the partition (130).

2. The submerged energy storage device according to claim 1, characterized in that: A spoiler (170) is provided on the inner wall of the immersion chamber (140) and on a side of the partition (130) close to the liquid inlet chamber (164), and the spoiler (170) extends in the direction of the battery unit (120).

3. The submerged energy storage device according to claim 2, characterized in that: The spoiler (170) comprises a long spoiler and a short spoiler, the length of the long spoiler extending in the direction of the battery unit (120) being greater than the length of the short spoiler extending in the direction of the battery unit (120), and the long spoiler and the short spoiler on the same wall surface are arranged at intervals.

4. The submerged energy storage device according to claim 3, characterized in that: The extension length of the long spoiler is denoted as h1, the extension length of the short spoiler is denoted as h2, and the distance between the wall surface where the spoiler (170) is located and the battery unit (120) is denoted as H, then 2h1<H<3h1, h2<h1<2h2.

5. The submerged energy storage device according to claim 1, characterized in that: A liquid input portion (160) is provided at the bottom of the box body (110), and the liquid input portion (160) includes a liquid inlet cavity (164). The liquid inlet cavity (164) is provided corresponding to the immersion cavity (140), and a plurality of liquid inlet holes (111) are provided between the liquid inlet cavity (164) and the immersion cavity (140). The liquid inlet cavity (164) is connected to a liquid input pipeline (161), and the liquid input pipeline (161) is connected to a liquid outlet (442) of the temperature regulating device (400). The liquid input pipeline (161) is provided on a side away from the partition (130) and is used for injecting immersion liquid into the liquid inlet cavity (164).

6. The submerged energy storage device according to claim 5, characterized in that: More than two battery cells (120) are arranged in the box body (110), and certain gaps are maintained between adjacent battery cells (120), between the battery cells (120) and the wall surface of the box body (110), and between the battery cells (120) and the partition (130), and a plurality of the liquid inlet holes (111) are evenly distributed in the gaps.

7. The submerged energy storage device according to claim 5, characterized in that: The liquid input part (160) is also provided with a liquid drain pipeline (162), which is arranged on a side away from the partition (130), and is used to drain the immersion liquid in the liquid input part (160) and the box (110) when necessary.

8. The submerged energy storage device according to claim 5, characterized in that: The bottom surface of the liquid inlet cavity (164) gradually rises from a direction close to the liquid input pipeline (161) to a direction close to the partition plate (130).

9. The submerged energy storage device according to claim 1, characterized in that: The overflow chamber (150) is connected to an overflow pipeline (163), and the overflow pipeline (163) is connected to a liquid inlet (441) of the temperature adjustment device (400).

10. An energy storage system, characterized in that: It comprises an immersed energy storage device as claimed in any one of claims 1 to 9.

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