Immersed liquid cooling energy storage system

Abstract

The embodiment of the invention relates to the technical field of electric energy storage, and discloses an immersed liquid cooling energy storage system. The liquid storage tank with the multiple liquid leakage holes is arranged above the battery cluster unit, the liquid outlet pipe outside the energy storage box conveys the cooling liquid into the liquid storage tank through the cooling pipe, and the cooling liquid in the liquid storage tank flows downwards from the liquid leakage holes under the action of gravity and cools the battery cluster unit. Therefore, the cooling liquid can accurately cool the battery cluster unit, reduce dead zones in the energy storage box, cool a heating concentrated area, and enhance the temperature equalization effect. Moreover, the cooling liquid flows and is attached to the surfaces of the battery cluster units under the action of gravity, so that an energy storage box does not need to be filled with the cooling liquid in a traditional immersion type liquid cooling manner, and the use amount of the cooling liquid can be reduced.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of electric energy storage technology, and in particular to an immersion liquid-cooled energy storage system. Background Art

[0002] New energy technologies such as wind energy and solar energy are developing rapidly, and the battery energy storage systems that support them are also developing rapidly. At present, in order to improve efficiency, battery energy storage systems are showing a technical trend of high energy density development, which easily increases the heat generation of battery energy storage systems and increases the risk of thermal runaway. Therefore, it is necessary to provide a battery energy storage system with efficient cooling performance.

[0003] Immersion liquid cooling technology is a cooling technology that directly immerses energy storage units such as battery packs or cells in insulating coolant, using the coolant to absorb the heat generated by the energy storage unit during operation to ensure that the battery operates within the optimal temperature range. Compared with traditional air cooling technology, immersion liquid cooling has higher cooling efficiency and safety performance.

[0004] Existing immersion liquid cooling energy storage systems usually use insulating coolant to fill the energy storage cabinet so that the battery cells in the energy storage cabinet are immersed. However, the existing immersion liquid cooling method has the problem of insufficient heat exchange due to the dead zone in the energy storage cabinet and the different flow rates in different areas, resulting in poor temperature uniformity. Summary of the invention

[0005] The purpose of the embodiment of the present invention is to provide an immersion liquid-cooled energy storage system, which can reduce the dead zone inside the energy storage box, cool the area where heat is concentrated, reduce the amount of coolant used, and enhance the temperature equalization effect.

[0006] In order to solve the above technical problems, an embodiment of the present invention provides an immersion liquid-cooled energy storage system, comprising: An energy storage box; a battery cluster unit, arranged in the energy storage box; an infusion pipe, arranged on the outside of the energy storage box, the infusion pipe is used to transport coolant; a liquid storage tank, arranged in the energy storage box, the liquid storage tank comprises a bottom plate and a plurality of side plates connected to the bottom plate, the bottom plate is fixed to the top of the battery cluster unit and is provided with a plurality of leakage holes; a plurality of side plates are connected end to end in sequence along the edge of the bottom plate and extend in a direction away from the battery cluster unit; a cooling pipe is arranged on a side of the liquid storage tank away from the battery cluster unit, one end of the cooling pipe is connected to the infusion pipe, and the other end is arranged opposite to the liquid storage tank, the cooling pipe is used to transport coolant to the liquid storage tank, and the coolant flows downward through the leakage holes under the action of gravity and cools the battery cluster unit.

[0007] In the immersion liquid-cooled energy storage system of the embodiment of the present invention, a liquid storage tank with multiple leakage holes is arranged above the battery cluster unit. The liquid outlet pipe outside the energy storage box transports the coolant to the liquid storage tank through the cooling pipe. The coolant in the liquid storage tank flows downward from the leakage holes under the action of gravity and cools the battery cluster unit. In this way, the coolant can accurately cool the battery cluster unit, reduce the dead zone inside the energy storage box, cool the area where heat is concentrated, and enhance the temperature equalization effect. In addition, because the coolant flows and adheres to the surface of the battery cluster unit under the action of gravity, there is no need to fill the energy storage box with coolant like traditional immersion liquid cooling, which can reduce the amount of coolant used.

[0008] Optionally, it also includes a plurality of support members arranged at intervals along the vertical direction, the plurality of support members are fixed in the energy storage box, there are a plurality of battery cluster units, and the plurality of battery cluster units are arranged on the support members in a one-to-one correspondence; there are a plurality of cooling pipes, which are arranged at intervals along the vertical direction, one end of the plurality of cooling pipes is connected to the infusion pipe, and the other ends of the plurality of cooling pipes are arranged opposite to the liquid storage tank in a one-to-one correspondence.

[0009] Optionally, the battery cluster unit includes a plurality of battery cells, and a heat dissipation gap is provided between two adjacent battery cells, and the coolant in the liquid storage tank enters the heat dissipation gap through the liquid leakage hole to cool the battery cells.

[0010] Optionally, each of the cooling tubes has a plurality of branch tubes spaced apart in a horizontal direction, each of the branch tubes has a liquid outlet, and the plurality of branch tubes transport cooling liquid to the corresponding liquid storage tank through the corresponding liquid outlets.

[0011] Optionally, the liquid outlet is configured such that an inner dimension along a horizontal direction is larger than an inner dimension along a vertical direction.

[0012] Optionally, the plurality of leakage holes are arranged in an array, and some of the leakage holes are arranged along the extension direction of the heat dissipation gap and face the heat dissipation gap.

[0013] Optionally, the liquid leakage hole facing the heat dissipation gap is arranged facing the liquid outlet.

[0014] Optionally, a drainage portion is provided on the edge of the leakage hole opposite to the heat dissipation gap on the side away from the side plate, one end of the drainage portion is connected to the edge of the leakage hole, and the other end is connected to the side wall of the battery cell, and the drainage portion is used to drain the coolant flowing out of the leakage hole to the side wall of the battery cell.

[0015] Optionally, an edge of the leakage hole facing the heat dissipation gap in the arrangement direction of the battery cells does not exceed an edge of a side wall of the battery cells.

[0016] Optionally, at least one of the side panels is provided with at least one overflow port. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0018] Figure 1 is a structural schematic diagram of an immersion liquid-cooled energy storage system according to a first embodiment of the present invention; Figure 2 is a schematic structural diagram of a layer battery cluster of an immersion liquid-cooled energy storage system according to a first embodiment of the present invention; Figure 3 is a schematic structural diagram of a liquid storage tank of an immersion liquid-cooled energy storage system according to a first embodiment of the present invention; Figure 4 yes Figure 2 A top view schematic diagram of a layer battery cluster; Figure 5 1 is a schematic structural diagram of cooling pipes and branch pipes of an immersion liquid-cooled energy storage system according to a first embodiment of the present invention; Figure 6 yes Figure 5 A bottom view schematic diagram of a cooling pipe and a branch pipe; Figure 7 yes Figure 4 Schematic cross-sectional view of the layer battery cluster along line AA'; Figure 8 is a schematic structural diagram of a shell of an immersion liquid-cooled energy storage system according to a second embodiment of the present invention; Fig. 9 yes Figure 8 A schematic top view of a housing; Fig.10 2. It is a schematic diagram of the explosion structure of the housing and the layer battery cluster of the immersion liquid-cooled energy storage system according to the second embodiment of the present invention; Fig.11 is a schematic structural diagram of another shell of an immersion liquid-cooled energy storage system according to a second embodiment of the present invention; Fig.12 yes Fig.11 Schematic diagram of a top view of the shell. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, it can be understood by those skilled in the art that in the embodiments of the present invention, many technical details are provided to enable readers to better understand the present invention. However, even without these technical details and various changes and modifications based on the following embodiments, the technical scheme claimed in the present invention can be implemented.

[0020] In the embodiments of the present invention, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. These terms are mainly used to better describe the present invention and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific direction, or to be constructed and operated in a specific direction.

[0021] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those skilled in the art, the specific meanings of these terms in the present invention can be understood according to specific circumstances.

[0022] In addition, the terms "installed", "set", "provided with", "opened", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] In addition, the terms "first", "second", etc. are mainly used to distinguish different devices, elements or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance and quantity of the indicated devices, elements or components. Unless otherwise specified, "plurality" means two or more.

[0024] In actual operation, the existing immersion liquid-cooled energy storage system has a temperature stratification phenomenon in which the upper layer is hot and the lower layer is cold because the density of the liquid after heating decreases and it gathers in the upper layer of the energy storage box. The coolant flow rate at different positions is different, and the heat exchange rate between the battery cell and the coolant is uneven. The above defects lead to the existence of dead zones in the energy storage box, and the problem of insufficient heat exchange caused by different flow rates in different areas, resulting in poor temperature equalization effect.

[0025] In an immersion liquid-cooled energy storage system according to one embodiment of the present invention, a liquid storage tank with multiple leakage holes is provided above the battery cluster unit, and a liquid outlet pipe outside the energy storage box transports the coolant to the liquid storage tank through a cooling pipe. The coolant in the liquid storage tank flows downward from the leakage holes under the action of gravity and cools the battery cluster unit. In this way, the coolant can accurately cool the battery cluster unit, reduce the dead zone inside the energy storage box, cool the area where heat is concentrated, and enhance the temperature equalization effect. In addition, since the coolant flows and adheres to the surface of the battery cluster unit under the action of gravity, there is no need to fill the energy storage box with coolant like traditional immersion liquid cooling, which can reduce the amount of coolant used.

[0026] It should be noted that the "immersion liquid-cooled energy storage system" referred to in this embodiment can be either an industrial and commercial energy storage system (referred to as industrial and commercial storage) or a large-scale energy storage system (referred to as large storage). Industrial and commercial storage usually serves industrial and commercial users, with a relatively small scale, and a capacity generally ranging from a few kilowatts to several megawatts, while large storage serves a wider range of power grids and energy markets, with a larger scale, and a capacity usually of tens of megawatts or even larger.

[0027] The following is a detailed description of the implementation details of the submerged liquid-cooled energy storage system of the first embodiment of the present invention. The following content is only the implementation details provided for easy understanding and is not necessary for the implementation of this solution. See also Figures 1 to 3 The submerged energy storage system 100 of this embodiment includes: an energy storage box 110, a battery cluster unit 120 arranged in the energy storage box 110, a liquid infusion pipe 130 arranged outside the energy storage box 110, the liquid infusion pipe 130 is used to transport coolant, and a liquid storage tank 140 arranged in the energy storage box 110, and a cooling pipe 150 arranged on the side of the liquid storage tank 140 away from the battery cluster unit 120.

[0028] The liquid storage tank 140 includes a bottom plate 141 and a plurality of side plates 142 connected to the bottom plate 141. The bottom plate 141 is fixed to the top of the battery cluster unit 120 and is provided with a plurality of leakage holes 141a. The plurality of side plates 142 are connected end to end along the edge of the bottom plate 141 and extend in a direction away from the battery cluster unit 120.

[0029] One end of the cooling tube 150 is connected to the infusion tube 130 , and the other end is disposed opposite to the liquid storage tank 140 . The cooling tube 150 is used to transport coolant to the liquid storage tank 140 . The coolant flows downward through the leakage hole 141 a under the action of gravity and cools the battery cluster unit 120 .

[0030] During the operation of the battery cluster unit 120, the liquid delivery pipe 130 delivers the coolant to the cooling pipe 150, and the coolant flows into the liquid storage tank 140 through the cooling pipe 150, is dispersed by the leakage hole 141a of the liquid storage tank 140, and then flows downward under the action of gravity to cool the battery cluster unit 120. In this way, the coolant can accurately cool the battery cluster unit 120, reduce the dead zone inside the energy storage box 110, cool the area where heat is concentrated, enhance the temperature uniformity effect, and also reduce the amount of coolant used.

[0031] It is understood that the coolant may flow down from the leakage hole 141a in the form of drops or in a continuous "water stream". When it flows down in the form of drops, the dripping speed may be controlled by controlling the flow rate per unit time of the cooling tube 150. In addition, due to the arrangement of the embodiment, the coolant may cover the surface of the battery cluster unit 120, and the battery cluster unit 120 may also be regarded as immersion liquid cooling.

[0032] At least one side plate 142 of the liquid storage tank 140 may be provided with at least one overflow port 142a, and the overflow port 142a may prevent the coolant from accumulating in the liquid storage tank 140. In this embodiment, the overflow port 142a may also be used as a wiring harness outlet of the battery cluster unit 120, so that the overall structure of the immersion liquid-cooled energy storage system 100 may be simplified.

[0033] The overflow port 142a may be a notch provided at the top edge of the side plate 142, or may be a through hole provided in the middle or lower part of the side plate 142. In some embodiments, the overflow port 142a may be provided in the vertical direction, and its diameter gradually decreases from top to bottom, for example, it may be provided in an inverted triangle, an inverted trapezoid, a semicircle, a semi-ellipse or other similar shapes. In this way, when the coolant accumulation in the liquid storage tank 140 is more serious, the liquid level is higher, and the diameter of the overflow port 142a is larger, so the coolant can be discharged faster to alleviate the coolant accumulation. When the coolant accumulation is alleviated, the liquid level is reduced, and the position corresponding to the smaller diameter of the overflow port 142a can reduce the flow rate of the coolant flowing out of the overflow port 142a, while alleviating the coolant accumulation, ensuring that more coolant can flow downward from the leakage hole 141a to cool the battery cluster unit 120, so that the coolant has a higher utilization rate.

[0034] The edge of the overflow port 142a formed by the side plate 142 may be provided with a flow guide structure, so as to solve the problem that the edge of the overflow port 142a blocks the flow of coolant due to processing errors during the processing of the product. For example, a chamfer may be provided at the edge of the overflow port 142a formed by the side plate 142, so that the thickness of the side plate 142 in this area gradually decreases in the direction from the inner edge of the side plate 142 toward the outer edge of the side plate 142. Optionally, the chamfer may be an oblique chamfer or a round chamfer.

[0035] The immersion liquid-cooled energy storage system 100 further includes a liquid outlet pipe (not shown) disposed at the bottom of the energy storage box 110, one end of the liquid outlet pipe is connected to the energy storage box 110 and communicates with the internal space of the energy storage box 110, and the other end is located outside the energy storage box 110. The liquid outlet pipe is used to discharge the coolant accumulated inside the energy storage box 110 to realize the circulation of the coolant.

[0036] Outside the energy storage box 110, the immersion liquid-cooled energy storage system 100 may be provided with a circulation device (not shown), such as a pump, and a cooling device, such as a condensing device. The pump may provide power to drive the coolant to flow out of the liquid outlet pipe and then re-enter the energy storage box 110 for cooling. It is understood that before the coolant re-enters the energy storage box 110 for cooling, the coolant is cooled by the cooling device so that the coolant can efficiently cool the battery cluster unit 120.

[0037] It should be noted that the energy storage box 110 is an immersion box of the immersion liquid-cooled energy storage system 100, which is used to accommodate the battery cluster and the coolant. The immersion liquid-cooled energy storage system 100 also has a packaging box (not shown) for accommodating the energy storage box 110 and the above-mentioned circulation device and cooling device. In addition, the circuit system including the power control board, inverter and other control devices in the immersion liquid-cooled energy storage system 100 is also arranged in the packaging box.

[0038] A valve can be provided at the outlet pipe, and the circulation speed of the coolant can be controlled by controlling the flow rate of the valve and the flow rate of the liquid infusion pipe 130. In addition, if there is a thermal runaway of the battery inside the immersion liquid-cooled energy storage system 100, the valve flow rate can be reduced or closed, and the flow rate of the liquid infusion pipe 130 can be increased at the same time, so that the internal space of the energy storage box 110 is completely filled with coolant, achieving full immersion, and effectively controlling thermal runaway.

[0039] See again Figure 1 The immersion liquid-cooled energy storage system 100 also includes a support member 160 fixed in the energy storage box 110. There is at least one support member 160, which divides the internal space of the energy storage box 110 into at least two spaces distributed in the vertical direction for accommodating the battery cluster unit 120.

[0040] In some embodiments, there are multiple support members 160, and the multiple support members 160 are arranged at intervals in the vertical direction, dividing the internal space of the energy storage box 110 into multiple spaces distributed in the vertical direction for accommodating the battery cluster units 120. Correspondingly, a corresponding liquid storage tank 140 is provided on the top of each battery cluster unit 120. At this time, the cooling pipe 150 is also arranged in multiple numbers and arranged at intervals in the vertical direction. Each cooling pipe 150 has one end connected to the infusion pipe 130, and the other end of each cooling pipe 150 is arranged above the corresponding liquid storage tank 140, for inputting coolant into the corresponding liquid storage tank 140. The support member 160 is used to support the battery cluster unit 120. It can be understood that the support member 160 can be a support plate, a bracket, etc., and the multiple support members 160 can be an integrated structure or an independent structure.

[0041] When the support member 160 is a support plate, it can be set as a liquid cooling plate, the plate is provided with a liquid cooling channel for conveying cooling liquid, the liquid cooling plate is provided with a liquid inlet and a first liquid outlet, the liquid inlet can be connected to the cooling pipe 150, the first liquid outlet can be kept open, or it can be connected to a pipeline, through which the cooling liquid flowing out of the liquid cooling plate is conveyed to the bottom of the energy storage box 110. In this way, the support member 160, as a liquid cooling plate, can cool down the bottom of the battery cluster unit 120, further improving the cooling effect of the battery cluster unit 120 and the overall temperature uniformity effect of the energy storage system.

[0042] When a liquid cooling channel is provided inside the support member 160 , the liquid cooling channel can be provided as a serpentine channel to improve the cooling effect. In addition, to facilitate the connection between the first liquid outlet and the cooling pipe 150 , the first liquid outlet can be provided on a side of the support member 160 close to the cooling pipe 150 .

[0043] When the support member 160 is a bracket, such as a grid-shaped bracket, it is convenient for the coolant flowing out of the liquid storage tank 140 to flow downward, which is beneficial to the circulation of the coolant.

[0044] In some other embodiments, a support member 160 may have multiple battery cluster units 120 arranged in a horizontal direction, and these battery cluster units 120 form a layer battery cluster. Each battery cluster unit 120 has a corresponding liquid storage tank 140, and each liquid storage tank 140 also has a corresponding cooling pipe 150. In this case, the liquid infusion tube 130 can be connected to multiple liquid distribution tubes (not shown) in the vertical direction, and each liquid distribution tube is connected to multiple cooling pipes 150 corresponding to the multiple battery cluster units 120 arranged on a support member 160.

[0045] Or, see Figures 2 to 4Each cooling tube 150 may be connected to a plurality of branch tubes 151, and the plurality of branch tubes 151 are arranged in a horizontal direction, for example, they may be arranged in sequence along the arrangement direction of the plurality of battery cluster units 120. Each branch tube 151 has a second liquid outlet 151a, and the plurality of branch tubes 151 on a cooling tube 150 are used to transport coolant to the liquid storage tank 140 corresponding to the cooling tube 150. In this way, coolant can be transported to different liquid storage tanks 140 at the same time, and the coolant can flow downward from the plurality of leakage holes 141a to cool the battery cells 121, thereby improving the cooling efficiency.

[0046] join Figure 5 and Figure 6 In some embodiments, the second liquid outlet 151a is configured such that the inner dimension in the horizontal direction is larger than the inner dimension in the vertical direction. Alternatively, the branch pipe 151 may be configured such that the dimension in the horizontal direction is larger than the dimension in the vertical direction. In other words, the branch pipe 151 may be configured to be flat, which may reduce the dimension in the vertical direction of the branch pipe 151 and thus reduce the height of the immersion liquid-cooled energy storage system 100. Furthermore, the cooling pipe 150 may also be configured to be flat.

[0047] Correspondingly, the second liquid outlet 151a can be set to a triangle, a prism, a rectangle, an oval, an ellipse, a wavy line, etc., which can not only reduce the volume occupied by the flow channel in the vertical direction, but also increase the contact area between the coolant flowing out of the second liquid outlet 151a and the bottom plate 141, further accelerating the speed at which the coolant covers the bottom plate 141 and improving the cooling efficiency.

[0048] The portion of the side plate 142 near the second liquid outlet 151a may be bent or tilted toward the inside of the liquid storage tank 140; or, a plate-like structure extending toward the second liquid outlet 151a may be provided at the top of the portion of the side plate 142 near the second liquid outlet 151a; or, the distance between the second liquid outlet 151a and the bottom plate 141 may be reduced to reduce or avoid the impact of the coolant on the bottom plate 141. This arrangement can avoid splashing of the coolant when it flows out of the second liquid outlet 151a.

[0049] It is understandable that the size of the second liquid outlet 151a can be set differently according to the actual size of the immersion liquid-cooled energy storage system 100, which can also reduce or avoid splashing of the coolant. For example, the diameter of the liquid outlet 151a can be set to 10mm-50mm.

[0050] Due to the large specifications of commercial or large storage, the existing liquid cooling channel design cannot ensure the consistency of cooling efficiency in different areas of the energy storage system. For example, there are some areas in the energy storage system that cannot be reached and immersed by the coolant, or the coolant flow rate in different areas of the energy storage system is different, and the heat exchange efficiency is significantly different. The heat exchange efficiency of some areas is low. The areas that cannot be immersed by the coolant and the areas with low heat exchange efficiency are usually called dead zones. The gaps between adjacent batteries in the energy storage system are typical locations for the formation of dead zones. Therefore, allowing the coolant to immerse the gaps between batteries and improving the flow efficiency of the coolant in the gaps between batteries are important means to reduce dead zones.

[0051] See also Figure 7 The battery cluster unit 120 generally includes a plurality of battery cells 121, and a heat dissipation gap 122 is provided between two adjacent battery cells 121. Specifically, the coolant flowing out of the leakage hole 141a of the liquid storage tank 140 enters the heat dissipation gap 122 and contacts the side wall of the battery cell 121 to achieve heat exchange.

[0052] Corresponding to the multiple heat dissipation gaps 122 formed by the multiple battery cells 121, at least part of the multiple leakage holes 141a arranged in the array are arranged along the extension direction of the heat dissipation gap 122 and are directly opposite to the heat dissipation gap 122. Specifically, each heat dissipation gap 122 extends along a straight line, and there are multiple leakage holes 141a directly opposite to the heat dissipation gap 122, and are arranged along the extension direction of the heat dissipation gap 122. Moreover, each heat dissipation gap 122 has multiple leakage holes 141a corresponding to it. Such a setting allows the coolant to accurately enter the heat dissipation gap 122 between adjacent battery cells 121. At the same time, the coolant at different positions flows downward under the action of gravity, and the fluidity tends to be consistent, which can reduce the cooling dead zone of the immersion liquid-cooled energy storage system 100 and improve the overall temperature uniformity effect.

[0053] See again Figure 4 and Figure 7 In some embodiments, the leakage holes 141a can also be arranged in a staggered manner. Specifically, considering the series connection requirements of multiple adjacent battery cells 121, the electrodes of adjacent battery cells 121 need to be electrically connected through staggered metal sheets 124. Since the metal sheets 124 need to occupy part of the space of the bottom plate 141, the leakage holes 141a are arranged at positions on the bottom plate 141 where the metal sheets 124 are not arranged, while the leakage holes 141a may not be arranged in areas where the metal sheets 124 are arranged. Therefore, the leakage holes 141a are arranged in a staggered manner as a whole. At this time, a heat dissipation gap 122 may correspond to a larger leakage hole 141a, or to multiple smaller leakage holes 141a.

[0054] In some other embodiments, the middle portion of the metal sheet 124 of two adjacent battery cells 121 connected in series may be bent and bulged in a direction away from the battery cell 121, and a space may be reserved below the portion of the metal sheet 124. Linear leakage holes 141a may be provided in the area of ​​the bottom plate 141 facing the portion of the metal sheet 124, so that the coolant can pass through these linear leakage holes 141a into the heat dissipation gaps 122 between the corresponding adjacent battery cells 121.

[0055] Optionally, the specific shape of the leakage hole 141a can be a circular hole, an elliptical hole, a linear hole, a waisted circular hole, a curved hole, a broken line hole or a through hole of other shapes. When the shape of the leakage hole 141a is a linear hole, its extension direction is roughly the same as the extension direction of the heat dissipation gap 122. In this way, the contact area between the coolant flowing out of the leakage hole 141a and the side wall of the battery cell 121 can be increased to improve the cooling efficiency. It can be understood that circular through holes usually have higher flow efficiency than square through holes, and when the diameter of the circular hole is the same as the short axis of the elliptical hole and the diameter of the semicircular part of the waisted circular hole, the flow rate is also larger because the elliptical hole and the waisted circular hole have a larger area. When the leakage hole 141a is set to a square hole, the flow efficiency of the coolant passing through the leakage hole 141a can be improved by setting the hole to a square hole with rounded corners, and / or setting the edge of the hole to a chamfer.

[0056] In some other embodiments, the length of the branch tube 151 can be extended, and a plurality of second liquid outlets 151a can be spaced apart on the branch tube 151, so that the branch tube 151 can simultaneously transport coolant to different positions of the liquid storage tank 140, so that the coolant quickly fills the liquid storage tank 140, thereby improving the cooling efficiency.

[0057] The leakage hole 141a facing the heat dissipation gap 122 is arranged opposite to the second liquid outlet 151a. In this way, the coolant flowing out of the second liquid outlet 151a can directly flow to the position where the corresponding leakage hole 141a is located, and then enter the heat dissipation gap 122 from the leakage hole 141a there, so as to achieve accurate and rapid heat dissipation.

[0058] In some embodiments, the edge of the leakage hole 141a facing the heat dissipation gap 122 is provided with a drainage portion (not shown) on the side away from the side plate 142, one end of the drainage portion is connected to the edge of the leakage hole 141a, and the other end is connected to the side wall of the battery cell 121, and the drainage portion is used to drain the coolant flowing out of the leakage hole 141a to the side wall of the battery cell 121. For example, an inclined wall can be provided on one side of the bottom plate 141 away from the side plate 142 and at the edge corresponding to the leakage hole 141a, one end of the inclined wall is connected to the edge of the leakage hole 141a, and the other end is in contact with the side wall of the battery cell 121. When the coolant flows out of the leakage hole 141a, the coolant is affected by the inclined wall, flows along the inclined wall, and then flows from the inclined wall to the side wall of the battery cell 121.

[0059] Optionally, the position where the inclined wall meets the edge of the leakage hole 141 a may be set as an inclined chamfer or a rounded chamfer, which can better achieve the drainage effect and drain the coolant to the side wall of the battery cell 121 .

[0060] In some other embodiments, the edge of the leakage hole 141a facing the heat dissipation gap 122 in the arrangement direction of the battery cells 121 does not exceed the edge of the side wall of the battery cell 121. For example, the edge of the leakage hole 141a may just coincide with the edge of the side wall of the battery cell 121, so that the coolant flowing out of the leakage hole 141a can flow directly to the side wall of the battery cell 121. Alternatively, the edge of the leakage hole 141a may expose a portion of the edge of the side wall of the battery cell 121, so that the coolant can also flow directly to the side wall of the battery cell 121.

[0061] It is understandable that the position of the bottom plate 141 opposite to the two side walls of each battery cell 121 parallel to the arrangement direction of the multiple battery cells 121 may also be provided with the above-mentioned leakage hole 141a, so that the four side walls of the battery cell 121 perpendicular to the bottom plate 141 can be cooled by the coolant.

[0062] The bottom plate 141 may be provided with a guide structure in the area near the leakage hole 141a, so that it can be avoided that the bottom plate 141 near the leakage hole 141a partially blocks the coolant from flowing downward through the leakage hole 141a due to errors during the manufacturing process of the product. For example, the thickness of the part of the bottom plate 141 near the leakage hole 141a can be gradually reduced, and specifically, an oblique chamfer or a round chamfer can be provided at the edge of the leakage hole 141a; or, a guide groove connected to the leakage hole 141a can be provided in the part of the bottom plate 141 near the leakage hole 141a, and the coolant can flow to the leakage hole 141a through the guide groove after entering the guide groove.

[0063] The bottom plate 141 may be provided with a plurality of positioning grooves (not shown), the contours of the positioning grooves match the contours of the electrodes of the battery cell 121, and the positioning grooves are used to match and position the electrodes of the battery cell 121. When assembling the battery cluster unit 120, the electrodes of the battery cell 121 may be aligned with the positioning grooves and assembled into the positioning grooves, and the positioning is performed using the pre-designed positioning grooves, which is conducive to speeding up the assembly of the battery cluster unit 120 and maintaining the consistency of the heat dissipation gap 122.

[0064] See again Figure 3 and Figure 4 Furthermore, the bottom plate 141 may be provided with a plurality of pressure relief holes 141 b, and the pressure relief holes 141 b are used to expose the explosion-proof valve 121 a on the top of the battery cell 121 , so that the safety performance of the immersion liquid-cooled energy storage system 100 can be guaranteed.

[0065] In this embodiment, the liquid storage tank 140 can be made of transparent structural plastic, and then cured by UV (Ultraviolet), so that the multiple battery cells 121 are bonded and fixed to the liquid storage tank 140 to form a whole. In this way, the liquid storage tank 140 can also fix the multiple battery cells.

[0066] In some embodiments, a liquid collecting tank (not shown) may be provided below each battery cluster unit 120, and the battery cluster unit 120 is placed in the liquid collecting tank, and the depth of the liquid collecting tank is less than the height of the battery cell 121. In this way, when the coolant flows downward from the heat dissipation gap 122, the liquid collecting tank can temporarily collect the coolant and immerse the bottom surface of the battery cell 121 for cooling. When there is a lot of coolant, the coolant may overflow from the liquid collecting tank and flow to the bottom of the energy storage box 110.

[0067] The immersion liquid-cooled energy storage system of the second embodiment of the present invention is substantially the same as the immersion liquid-cooled energy storage system of the first embodiment, with the main difference being that the multiple battery cluster units 120 carried by the support 160 are installed in the housing 210, that is, the layered battery clusters are installed in the housing 210, which can be regarded as forming a battery pack. In this case, there is no need to provide a liquid collecting tank below the battery cluster unit 120.

[0068] See also Figures 8 to 10 The housing 210 includes a second bottom plate 211 and a top plate 212 that are arranged opposite to each other, and a plurality of second side plates 213 that are connected end to end in sequence and form a cylindrical side wall. The second bottom plate 211 and the top plate 212 are respectively connected to the edges of the cylindrical side wall formed by the plurality of second side plates 213. With such an arrangement, when necessary, the cooling liquid delivered by the cooling pipe 150 can fill the entire internal space of the housing 210, and the multiple battery cluster units 120 can be fully immersed in cooling, which can not only improve the cooling efficiency, but also prevent the thermal runaway phenomenon from spreading by fully immersing the cooling liquid when some of the battery cluster units 120 have thermal runaway.

[0069] See also Figure 8 and Fig. 9 In some embodiments, the second bottom plate 211 carrying multiple battery cluster units 120 can be set as a liquid cooling plate, and a cooling channel for the flow of coolant is provided inside the second bottom plate 211. The portion of the second bottom plate 211 protruding from the second side plate 213 can be provided with a liquid inlet 211a and a third liquid outlet 211b to achieve the circulation of coolant in the second bottom plate 211. The second bottom plate 211 is set as a liquid cooling plate to cool the bottom of the battery cluster unit 120. It is understandable that the cooling channel inside the second bottom plate 211 can be set as a serpentine channel to improve the cooling effect.

[0070] See also Fig. 9 , Fig.11 and Fig.12It can be understood that, since the overall flow direction of the coolant is from top to bottom, the fourth liquid outlet 213a can be set at the lower position of the second side plate 213, and the fourth liquid outlet 213a can discharge the coolant inside the shell 210 to achieve the circulation of the coolant. Alternatively, the fourth liquid outlet 213a can also be set on the second bottom plate 211. Compared with setting the fourth liquid outlet 213a on the lower side of the second side plate 213, setting the fourth liquid outlet 213a on the second bottom plate 211 has a lower horizontal height, which is more conducive to discharging the coolant accumulated in the shell 210 to achieve circulation.

[0071] See again Fig.10 In this embodiment, a cover plate 220 can be provided on the side of the liquid storage tank 140 away from the battery cluster unit 120. The cover plate 220 can limit the position of the wiring harness of the battery cluster unit 120, making the wiring inside the immersion liquid-cooled energy storage system more regular. In addition, the positive and negative electrodes of the battery cluster unit 120 can be indicated on the cover plate 220, which is convenient for operators to accurately connect the circuit inside the system when assembling the immersion liquid-cooled energy storage system.

[0072] The above is a detailed introduction to the immersion liquid-cooled energy storage system provided by the embodiment of the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above implementation methods is only used to help understand the ideas of the present invention. There may be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. An immersion liquid-cooled energy storage system, It is characterized in that include: Energy storage box; A battery cluster unit is arranged in the energy storage box; A liquid infusion pipe, arranged outside the energy storage box, and used for conveying cooling liquid; A liquid storage tank is provided in the energy storage box, the liquid storage tank comprises a bottom plate and a plurality of side plates connected to the bottom plate, the bottom plate is fixed to the top of the battery cluster unit and is provided with a plurality of leakage holes; the plurality of side plates are connected end to end in sequence along the edge of the bottom plate and extend in a direction away from the battery cluster unit; A cooling tube is arranged on a side of the liquid storage tank away from the battery cluster unit, one end of the cooling tube is connected to the infusion tube, and the other end is arranged opposite to the liquid storage tank. The cooling tube is used to transport coolant to the liquid storage tank. The coolant flows downward through the leakage hole under the action of gravity and cools the battery cluster unit.

2. The immersion liquid-cooled energy storage system according to claim 1, It is characterized in that It also includes a plurality of support members arranged at intervals along the vertical direction, wherein the plurality of support members are fixed in the energy storage box, and the plurality of battery cluster units are arranged on the support members in a one-to-one correspondence; There are multiple cooling tubes, which are arranged at intervals in the vertical direction. One end of the multiple cooling tubes is connected to the infusion tube, and the other ends of the multiple cooling tubes are arranged opposite to the liquid storage tank in a one-to-one correspondence.

3. The immersion liquid-cooled energy storage system according to claim 1, It is characterized in that The battery cluster unit includes a plurality of battery cells, and a heat dissipation gap is provided between two adjacent battery cells. The coolant in the liquid storage tank enters the heat dissipation gap through the liquid leakage hole to cool the battery cells.

4. The immersion liquid-cooled energy storage system according to claim 3, It is characterized in that Each of the cooling tubes has a plurality of branch tubes spaced apart in a horizontal direction, each of the branch tubes has a liquid outlet, and the plurality of branch tubes transport cooling liquid to the corresponding liquid storage tank through the corresponding liquid outlets.

5. The immersion liquid-cooled energy storage system according to claim 4, It is characterized in that The liquid outlet is configured such that an inner dimension along a horizontal direction is larger than an inner dimension along a vertical direction.

6. The immersion liquid-cooled energy storage system according to claim 4, It is characterized in that The plurality of leakage holes are arranged in an array, and some of the leakage holes are arranged along the extension direction of the heat dissipation gap and face the heat dissipation gap.

7. The immersion liquid-cooled energy storage system according to claim 6, It is characterized in that The liquid leakage hole facing the heat dissipation gap is arranged facing the liquid outlet.

8. The immersion liquid-cooled energy storage system according to claim 6, It is characterized in that A drainage portion is provided on the edge of the leakage hole facing the heat dissipation gap on the side away from the side plate, one end of the drainage portion is connected to the edge of the leakage hole, and the other end is connected to the side wall of the battery cell. The drainage portion is used to drain the coolant flowing out of the leakage hole to the side wall of the battery cell.

9. The immersion liquid-cooled energy storage system according to claim 6, It is characterized in that The edge of the leakage hole facing the heat dissipation gap in the arrangement direction of the battery cells does not exceed the edge of the side wall of the battery cells.

10. The immersion liquid-cooled energy storage system according to any one of claims 1 to 9, It is characterized in that At least one of the side plates is provided with at least one overflow opening.

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