Liquid cooling system for liquid cooling battery pack

Abstract

The invention discloses a liquid cooling system for a liquid cooling battery pack, and aims to overcome the defects that an immersed cooling scheme is high in air tightness requirement and difficult to maintain. The liquid cooling device comprises a bottom liquid cooling plate, a liquid cooling pipeline and a plurality of side liquid cooling plates, the bottom liquid cooling plate is communicated with the side liquid cooling plates through the liquid cooling pipeline, the bottom liquid cooling plate is provided with a bottom flow channel, the side liquid cooling plates are provided with side flow channels, the bottom flow channel is communicated with the side flow channels, and the bottom liquid cooling plate is attached to the bottom wall of a battery module. The side liquid cooling plate is attached to the side wall of the battery module in the width direction, and the bottom liquid cooling plate and the side liquid cooling plate exchange heat with the battery module through cooling capacity generated by cooling liquid flowing through the bottom flow channel and the side flow channel. According to the liquid-cooled battery pack, the side liquid-cooled plates are arranged between the adjacent battery modules on the basis of an existing liquid-cooled battery pack, and flow channels of the side liquid-cooled plates and the bottom liquid-cooled plates are communicated, so that the heat dissipation area of the battery modules is expanded, the temperature difference between the upper and lower positions in the battery modules is reduced, and the identity of the battery modules is improved.

Description

Technical Field

[0001] The present invention relates to the field of thermal management of energy storage batteries, and more particularly, to a liquid cooling system for a liquid-cooled battery pack. Background Art

[0002] Energy storage batteries are devices that can store electrical energy and release it when needed. They are widely used in power systems, renewable energy, electric vehicles, portable electronic devices and other fields.

[0003] Energy storage batteries store and release energy through the process of converting chemical energy into electrical energy. During the charging process, electrical energy is converted into chemical energy and stored in the battery; during the discharging process, chemical energy is converted back into electrical energy and released.

[0004] The energy storage system generates a lot of heat during the charging and discharging process. If this heat is not effectively managed, it will cause the energy storage system to overheat, affect work efficiency, shorten service life, and even cause safety accidents. Among them, the temperature difference between the cells in the energy storage battery will have a significant impact on the performance and life of the battery. The temperature difference causes the battery monomer performance and capacity decay rate to be inconsistent. Since the battery cells in the battery pack are connected in series, the performance decline and capacity decay of any battery cell will affect the overall performance of the assembly; the single cell with a higher temperature ages faster, generates more heat, and is more likely to generate high temperature, forming a vicious cycle; excessive temperature difference inside the battery will cause uneven internal impedance, uneven current distribution, and uneven heat generation, which will affect the battery performance and accelerate the battery capacity decay; the charging and discharging efficiency is significantly affected by temperature, and the typical battery charging and discharging efficiency reaches the highest value between 20-40 degrees Celsius; the uneven temperature distribution caused by the temperature difference will reduce the overall performance of the battery cell; excessive temperature difference between the battery cells of the battery pack will destroy the identity of the battery pack, resulting in reduced battery pack performance.

[0005] As a three-dimensional structure, the energy storage battery can exchange heat with the outside world on all surfaces of its volume. The existing bottom surface heat exchange structure easily causes the uniformity of the upper and lower directions to decrease. Based on this, some technical solutions adopt an immersion solution, directly immersing the battery cell in the coolant, but this solution has high requirements for airtightness and is also difficult to maintain.

[0006] This application aims to improve this. Summary of the invention

[0007] The present invention overcomes the shortcomings of immersion cooling solutions, such as high airtightness requirements and difficult maintenance, and provides a liquid cooling system for a liquid-cooled battery pack, which can provide a cooling effect close to that of immersion in a manner similar to existing liquid cooling solutions, while having a maintainability close to that of existing liquid cooling solutions.

[0008] In order to solve the above technical problems, the present invention adopts the following technical solutions: A liquid cooling system for a liquid-cooled battery pack comprises a bottom liquid cooling plate, a liquid cooling pipeline and a plurality of side liquid cooling plates, wherein the bottom liquid cooling plate is connected to each side liquid cooling plate through the liquid cooling pipeline, the bottom liquid cooling plate has a bottom flow channel, the side liquid cooling plates have side flow channels, the bottom flow channels are connected to the side flow channels, the side flow channels corresponding to each side liquid cooling plate are connected in parallel, the bottom liquid cooling plate is fitted with the bottom wall of a battery module, the side liquid cooling plates are fitted with the side walls of the battery module in the width direction, and the bottom liquid cooling plate and the side liquid cooling plates respectively exchange heat with the battery module through the cooling energy generated by the cooling liquid flowing through the bottom flow channel and the side flow channel.

[0009] The side-mounted liquid cooling plate allows the cold energy to be directly transferred to the side wall of the battery module. Compared with the traditional liquid-cooled battery pack cold energy transfer method, this method has a larger contact area and can adjust the temperature of the battery module more quickly, finely and evenly. This method can achieve a thermal management effect similar to the immersion solution, but can avoid the risk of sealing failure caused by the immersion solution.

[0010] The side liquid cooling plate generates cold energy through the coolant flow channel in the internal side flow channel, and performs heat exchange by fitting with the side wall of the battery module. Each side liquid cooling plate is connected in parallel so that the amount of coolant passing through each side flow channel is similar, thereby controlling the upper limit of the cold energy that each side flow channel can provide per unit time to be similar. This feature controls the cold energy delivered to the battery module by the side liquid cooling plate to be similar, thereby ensuring the identity between each battery module.

[0011] Preferably, the side liquid cooling plate and the bottom liquid cooling plate are split structures, and the side liquid cooling plate and the bottom liquid cooling plate are formed independently. The split side liquid cooling plate and the bottom liquid cooling plate are arranged in a way that is easy to expand, and the split structure is easier to combine with the existing battery pack assembly process, and the difficulty of transforming the existing production line is reduced.

[0012] Preferably, the bottom flow channel includes a main water inlet channel, a water inlet branch channel, a heat exchange channel, a water outlet branch channel and a main water outlet channel. The main water inlet channel is connected to four water inlet branches, each of which is connected in parallel. Each water inlet branch channel is connected to two heat exchange channels, and the two heat exchange channels are connected in parallel. The main water outlet channel is connected to four water outlet branches, and each water outlet branch channel is connected to the corresponding two heat exchange channels to form a continuous flow channel. The bottom flow channel is provided with two levels of water channels, in which the water channels of the same level are connected in parallel. The four water inlet branches are connected in parallel to evenly share the coolant of the main water inlet channel. The two lower heat exchange channels are connected in parallel to evenly share the coolant of the same water inlet branch channel. The area occupied by the heat exchange channel is larger than that of the main water inlet channel, the water inlet branch channel, the water outlet branch channel and the main water outlet channel, thereby providing sufficient contact area for heat exchange.

[0013] Preferably, the bottom-mounted liquid cooling plate is connected to a bottom-mounted water inlet on the main water inlet, and the bottom-mounted liquid cooling plate is connected to a bottom-mounted water outlet on the main water outlet. The liquid cooling channel includes a water inlet liquid cooling pipeline and a water outlet liquid cooling pipeline. The water inlet liquid cooling pipeline is connected to the bottom water inlet, and the water outlet liquid cooling pipeline is connected to the bottom water outlet. Each water inlet branch is connected in parallel with each side flow channel. The bottom-mounted liquid cooling plate provides a bottom water inlet, which is connected to an external coolant circulation system and connected to the water inlet liquid cooling pipeline to receive coolant. The connected coolant is set on the main water inlet, so that the side flow channels are connected in parallel with each water inlet branch.

[0014] Preferably, the side liquid cooling plate is provided with an extension extending out of the battery module, the extension being provided with a side water inlet and a side water outlet, the side water inlet being connected to a water inlet liquid cooling pipeline, and the side water outlet being connected to a water outlet liquid cooling pipeline. The extension of the side liquid cooling plate extends out of the battery module and is used to connect the corresponding side water inlet and side water outlet.

[0015] Preferably, the orientation of the side water inlet and the side water outlet of the side liquid cooling plate is adaptively set according to the position of the side cooling plate in the liquid-cooled battery pack. For N battery modules, there are N+1 side liquid cooling plates, and the two sides of the side liquid cooling plates located between adjacent battery modules are respectively affixed to the two side walls of the two battery modules. The side wall of the outermost side liquid cooling plate is affixed to a side liquid cooling plate alone. Corresponding to the positions of these side liquid cooling plates, the extension portion located between the two battery modules has one of the side water inlet and the side water outlet on the front and back sides respectively. The extension portion of the side liquid cooling plate that is affixed to the outermost battery module and only affixed to the side wall of one battery module has a side water inlet and a side water outlet on the side close to the battery module.

[0016] Preferably, a plurality of isolated and equally spaced diverter islands are provided on the side liquid cooling plate, and the diverter islands are arranged in the side flow channel. The flow resistance generated by the side flow channel in the forward flow direction through the diverter islands is smaller than the flow resistance generated in the reverse flow direction. Through the structure, the reverse flow of the side liquid flow plate is limited.

[0017] Preferably, the diverter island is in the shape of a water drop with one end larger than the other end, and includes arc edges, one large and one small, at both ends and a straight edge connecting the ends of the two arcs, the two straight edges are arranged obliquely, and along the forward flow direction of the side flow channel, the smaller end of the diverter island is located at an upstream position. The structure guides the flow direction of the coolant, and when the coolant passes through in the forward direction, the flow resistance is small, and when the coolant passes through in the reverse direction, the flow resistance is large.

[0018] Preferably, the side flow channel has two rows of diverter islands, and the two rows of diverter islands are staggered. With the above features, when the coolant flow moves downstream, the flow channel it passes through can be approximately equivalent to ">", the flow moves from the left to the right, and the flow resistance is low. When it flows countercurrently, it can be equivalent to "<", the flow moves from the left to the right, and its principle is similar to that of a Tesla valve, which can increase the flow resistance and achieve an effect similar to a one-way valve.

[0019] Preferably, the side flow channel is in a horizontal "U" shape, and the side water inlet is located above the side water outlet. The structure further restricts the reverse flow by gravity, increasing the difficulty of reverse flow.

[0020] Compared with the prior art, the present invention has the following beneficial effects: (1) On the basis of the existing liquid-cooled battery pack, a side liquid cooling plate is arranged between adjacent battery modules. The flow channels of the side liquid cooling plate and the bottom liquid cooling plate are connected, so that the coolant passes through the side liquid cooling plate, thereby expanding the heat dissipation area of ​​the battery module, improving the heat dissipation efficiency, reducing the temperature difference between the upper and lower positions in the battery module, and improving the identity of the battery module; (2) By setting an asymmetric flow diversion island in the side liquid cooling plate, the forward and reverse flow resistances are controlled, thereby limiting the reverse flow and controlling the liquid flow environment in the side flow channel, so that the side liquid cooling plate works in a manner close to the preset value. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic diagram of the present invention; Figure 2 is a schematic diagram of a battery module of the present invention; Figure 3 is a schematic diagram of a bottom-mounted liquid cooling plate and a side-mounted liquid cooling plate of the present invention; Figure 4 is a schematic diagram of a bottom-mounted flow channel of the present invention; Figure 5 is a schematic diagram of a side flow channel of the present invention; Fig. 6A is a schematic diagram of a water inlet liquid cooling pipeline of the present invention; Figure 6B is a schematic diagram of a water outlet liquid cooling pipeline of the present invention; Figure 7 is a partial schematic diagram of a side flow channel in an embodiment of the present invention; In the figure: Bottom-mounted liquid cooling plate 1, bottom-mounted flow channel 10, main water inlet channel 11, water inlet branch channel 12, heat exchange channel 13, water outlet branch channel 14, main water outlet channel 15, bottom water inlet 16, bottom water outlet 17, liquid cooling pipeline 2, water inlet liquid cooling pipeline 21, water outlet liquid cooling pipeline 22, side-mounted liquid cooling plate 3, side flow channel 30, extension part 31, side water inlet 32, side water outlet 33, diverter island 34, circular diverter island 35, inner concave notch 36, battery cell 4, cable tie 5, end plate 6. DETAILED DESCRIPTION

[0022] The present disclosure is further described below in conjunction with the accompanying drawings and embodiments.

[0023] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0024] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0025] In the present disclosure, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are relational words determined only for the convenience of describing the structural relationships of the various parts or elements of the present disclosure, and do not specifically refer to any part or element in the present disclosure and should not be understood as limitations on the present disclosure.

[0026] In the present disclosure, terms such as "fixed connection", "connected", "connection", etc. should be understood in a broad sense, indicating that it can be fixedly connected, integrally connected or detachably connected; it can be directly connected or indirectly connected through an intermediate medium. For relevant scientific research or technical personnel in this field, the specific meanings of the above terms in the present disclosure can be determined according to specific circumstances, and they cannot be understood as limitations on the present disclosure.

[0027] Example: Ginseng Figure 1As shown, a liquid cooling system for a liquid-cooled battery pack includes a bottom liquid cooling plate 1, a liquid cooling pipeline 2 and a plurality of side liquid cooling plates 3. Among them, the bottom liquid cooling plate 1 is connected to each side liquid cooling plate 3 through the liquid cooling pipeline 2. The bottom liquid cooling plate 1 has a bottom flow channel 10, and the side liquid cooling plate 3 has a side flow channel 30, and the bottom flow channel 10 is connected to the side flow channel 30. The side flow channels 30 corresponding to each side liquid cooling plate 3 are connected in parallel. The bottom liquid cooling plate 1 is attached to the bottom wall of the battery module, and the side liquid cooling plate 3 is attached to the side wall of the battery module in the width direction. The bottom liquid cooling plate 1 and the side liquid cooling plate 3 respectively exchange heat with the battery module through the cooling energy generated by the cooling liquid flowing through the bottom flow channel 10 and the side flow channel 30.

[0028] Ginseng Figure 2 As shown, the battery module includes a plurality of battery cells 4, and heat insulating glue is provided between adjacent battery cells 4, and each battery cell 4 is fixed as a whole by an end plate 6 and a cable tie 5. Therefore, a cable tie 5 is provided on the side wall of the battery module, and the cable tie 5 protrudes relative to the side wall of the battery module to produce a height difference. The side wall of the battery module in the width direction is bonded to the side liquid cooling plate 3 by heat transfer glue, and the height difference is filled by the heat transfer glue. The heat transfer glue is used to fix the side liquid cooling plate 3 to the island battery module, and also to fix the side liquid cooling plate 3 by adhesion, so as to keep the side liquid cooling plate 3 fixed to the battery module. In some embodiments, two columns of battery cells 4 are bundled together. Similarly, the bottom liquid cooling plate 1 is also fixedly connected to the bottom wall of the battery module by heat transfer glue.

[0029] Ginseng Figure 3 As shown, the side liquid cooling plate 3 and the bottom liquid cooling plate 1 are split structures, and the side liquid cooling plate 3 and the bottom liquid cooling plate 1 are formed independently. The split side liquid cooling plate 3 and the bottom liquid cooling plate 1 are arranged in a way that is easy to expand, and the split structure is easier to combine with the existing battery pack assembly process, and the difficulty of transforming the existing production line is reduced.

[0030] Ginseng Figure 4 As shown, the bottom flow channel 10 includes a main water inlet channel 11, a water inlet branch channel 12, a heat exchange channel 13, a water outlet branch channel 14 and a main water outlet channel 15. The main water inlet channel 11 is connected to four water inlet branches 12, each water inlet branch channel 12 is connected in parallel, each water inlet branch channel 12 is connected to two heat exchange channels 13, and the two heat exchange channels 13 are connected in parallel. The main water outlet channel 15 is connected to four water outlet branches 14, and each water outlet branch channel 14 is connected to the corresponding two heat exchange channels 13 to form a continuous flow channel. The coolant enters the main water inlet channel 11 and then flows into the four water inlet branches 12. In each water inlet branch channel 12, it is again divided and enters the heat exchange channel 13. The coolant passing through the heat exchange channel 13 is collected in the corresponding water outlet branch channel 14, and the four water outlet branches 14 are collected in the main water outlet channel 15 again and finally leave the bottom liquid cold plate 1.

[0031] The bottom flow channel 10 is provided with two levels of water channels, wherein the water channels of the same level are connected in parallel. The four water inlet branches 12 are connected in parallel, and the cooling liquid of the total water inlet channel 11 is evenly divided. The two heat exchange channels 13 at the lower level are connected in parallel, and the cooling liquid of the same water inlet branch channel 12 is evenly divided. The area occupied by the heat exchange channel 13 is larger than that of the total water inlet channel 11, the water inlet branch channel 12, the water outlet branch channel 14 and the total water outlet channel 15, thereby providing sufficient contact area for heat exchange. In some embodiments, the heat exchange channel 13 is bent in a serpentine shape to increase the heat dissipation area.

[0032] In some embodiments, there are four battery modules installed in the liquid-cooled battery pack, and the battery modules are arranged side by side. The two heat exchange channels 13 corresponding to each water inlet branch channel 12 correspond to one battery module respectively. The two heat exchange channels 13 are symmetrically arranged relative to the central axis of the battery module.

[0033] The bottom-mounted liquid cooling plate 1 is connected to a bottom-mounted water inlet 16 on the main water inlet 11, and is connected to a bottom-mounted water outlet 17 on the main water outlet 15. The liquid cooling channel includes a water inlet liquid cooling pipeline 21 and a water outlet liquid cooling pipeline 22. The water inlet liquid cooling pipeline 21 is connected to the bottom-mounted water inlet 16, and the water outlet liquid cooling pipeline 22 is connected to the bottom water outlet 17. Each water inlet branch 12 is connected in parallel with each side flow channel 30. The bottom-mounted liquid cooling plate 1 provides a bottom-mounted water inlet 16, which is connected to an external coolant circulation system and is connected to a pipeline to receive coolant. The connected coolant is set on the main water inlet 11, so that the side flow channel 30 is connected in parallel with each water inlet branch 12.

[0034] Ginseng Figure 3 As shown, the side liquid cooling plate 3 is provided with an extension portion 31 extending out of the battery module, and the extension portion 31 is provided with a side water inlet 32 ​​and a side water outlet 33, the side water inlet 32 ​​is connected to the water inlet liquid cooling pipeline, and the side water outlet 33 is connected to the water outlet liquid cooling pipeline. The extension portion 31 of the side liquid cooling plate 3 extends out of the battery module and is used to connect the corresponding side water inlet 32 ​​and the side water outlet 33. The orientation of the side water inlet 32 ​​and the side water outlet 33 of the side liquid cooling plate 3 is adaptively set according to the position of the side cooling plate in the liquid-cooled battery pack. For N battery modules, there are N+1 side liquid cooling plates 3, and the two sides of the side liquid cooling plates 3 located between adjacent battery modules are respectively attached to the two side walls of the two battery modules. The side wall of the outermost side liquid cooling plate 3 is separately attached to a side liquid cooling plate 3. Corresponding to the positions of these side liquid cooling plates 3, the extension part 31 located between the two battery modules has one of the side water inlet 32 ​​and the side water outlet 33 on the front and back sides. The extension part 31 of the side liquid cooling plate 3 that is attached to the outermost battery module and only attached to the side wall of one battery module has the side water inlet 32 ​​and the side water outlet 33 on the side close to the battery module. The end plate 6 of the battery module is provided with a notch passing through the extension plate.

[0035] Based on the aforementioned bottom-mounted liquid cooling plate 1 structure, after the coolant enters the main water inlet 11, the coolant is distributed to the liquid cooling pipeline 2 and the water inlet branch 12. In the liquid cooling pipeline 2, the coolant enters the side flow channel 30 through the side water inlet 32. Fig. 6A , 6B As shown, specifically, the liquid cooling pipeline 2 includes a water inlet liquid cooling pipeline 21 and a water outlet liquid cooling pipeline 22. Both the water inlet liquid cooling pipeline 21 and the water outlet liquid cooling pipeline 22 are one-to-many structures. Specifically, in the solution of the four battery modules of the present application, the water inlet liquid cooling pipeline 21 and the water outlet liquid cooling pipeline 22 are one-to-five structures, respectively connected to the side water inlet 32 ​​and the side water outlet 33 of the side liquid cooling plate 3.

[0036] Ginseng Figure 5 As shown, the side liquid cooling plate 3 is provided with a number of isolated equally spaced diverter islands 34, which are arranged in the side flow channel 30. The flow resistance generated by the diverter islands 34 in the forward flow direction of the side flow channel 30 is smaller than the flow resistance generated in the reverse flow direction. The reverse flow of the side liquid flow plate is limited by the structure. Among them, the diverter island 34 is in the shape of a water droplet with one end larger and the other end smaller. The diverter island 34 includes arc edges, one large and one small, at both ends and a straight edge connecting the ends of the two arcs. The two straight edges are arranged obliquely. Along the forward flow direction of the side flow channel 30, the smaller end of the diverter island 34 is located at the upstream position. The flow direction of the coolant is guided by this structure. When the coolant passes through in the forward direction, the flow resistance is smaller, and when the coolant passes through in the reverse direction, the flow resistance is larger. Specifically, the side flow channel 30 has two rows of diverter islands 34, and the two rows of diverter islands 34 are staggered. Through the above-mentioned characteristics, when the coolant flow moves downstream, the flow channel it passes through can be approximately equivalent to “>”, and the flow moves from left to right, with lower flow resistance. When it flows upstream, it can be equivalent to “<”, and the flow moves from left to right. Its principle is similar to that of a Tesla valve, which can increase the flow resistance and achieve an effect similar to that of a one-way valve.

[0037] The two rows of flow-dividing islands 34 separate the side liquid cooling plate 3 to form three interconnected sub-flow channels. Figure 7 As shown, in some embodiments, the channel wall of the side channel 30 is provided with an inner concave notch 36, and the inner concave notch 36 can be a continuous corrugation, wherein the curvature of each corrugation in the upstream is smaller than that in the downstream. This structure enhances the flow resistance of the channel wall of the side channel 30 to the downstream flow is smaller than the flow resistance to the upstream flow.

[0038] In addition, the side flow channel 30 is in a horizontal "U" shape, and the side water inlet 32 ​​is located above the side water outlet 33. The structure further restricts the reverse flow by gravity, increasing the difficulty of reverse flow. Among them, a number of circular diverter islands 35 are provided at the turning point of the side flow channel 30. The circular diverter islands 35 are circular and located in the middle of the side flow channel 30.

[0039] The side liquid cooling plate 3 is set up so that the cold energy can be directly transferred to the side wall of the battery module. Compared with the traditional liquid-cooled battery pack cold energy transfer method, this method has a larger contact area and can adjust the temperature of the battery module more quickly, finely and evenly. This method can achieve a thermal management effect similar to the immersion solution, but can avoid the risk of sealing failure caused by the immersion solution.

[0040] The side liquid cooling plate 3 generates cooling through the cooling liquid flow channel in the internal side flow channel 30, and performs heat exchange by fitting with the side wall of the battery module. The side liquid cooling plates 3 are connected in parallel so that the amount of cooling liquid passing through each side flow channel 30 is similar, thereby controlling the upper limit of cooling that each side flow channel 30 can provide per unit time to be similar. This feature controls the cooling amount delivered to the battery module by the side liquid cooling plate 3 to be similar, thereby ensuring the identity between each battery module.

[0041] The embodiments described above are only preferred solutions of the present invention and are not intended to limit the present invention in any form. Other variations and modifications are possible without exceeding the technical solutions described in the claims.

Claims

1. A liquid cooling system for a liquid-cooled battery pack, characterized in that: It includes a bottom liquid cooling plate, a liquid cooling pipeline and several side liquid cooling plates. The bottom liquid cooling plate is connected to each side liquid cooling plate through the liquid cooling pipeline. The bottom liquid cooling plate has a bottom flow channel, and the side liquid cooling plates have side flow channels. The bottom flow channel is connected to the side flow channels. The side flow channels corresponding to each side liquid cooling plate are connected in parallel. The bottom liquid cooling plate is attached to the bottom wall of the battery module, and the side liquid cooling plates are attached to the side walls in the width direction of the battery module. The bottom liquid cooling plate and the side liquid cooling plates respectively exchange heat with the battery module through the cooling generated by the cooling liquid flowing through the bottom flow channel and the side flow channel.

2. A liquid cooling system for a liquid-cooled battery pack according to claim 1, characterized in that: The side liquid cooling plate and the bottom liquid cooling plate are split structures, and the side liquid cooling plate and the bottom liquid cooling plate are independently formed.

3. The liquid cooling system for a liquid-cooled battery pack according to claim 1, characterized in that: The bottom flow channel includes a main water inlet channel, a water inlet branch channel, a heat exchange channel, a water outlet branch channel and a main water outlet channel. The main water inlet channel is connected to four water inlet branches, each water inlet branch channel is connected in parallel, each water inlet branch channel is connected to two heat exchange channels, and the two heat exchange channels are connected in parallel. The main water outlet channel is connected to four water outlet branches, and each water outlet branch channel is connected to the corresponding two heat exchange channels to form a continuous flow channel.

4. A liquid cooling system for a liquid-cooled battery pack according to claim 3, characterized in that: The bottom-mounted liquid cooling plate is connected to a bottom water inlet on the main water inlet channel, and the bottom-mounted liquid cooling plate is connected to a bottom water outlet on the main water outlet channel. The liquid cooling channel includes an inlet liquid cooling pipeline and an outlet liquid cooling pipeline. The inlet liquid cooling pipeline is connected to the bottom water inlet, and the outlet liquid cooling pipeline is connected to the bottom water outlet. Each water inlet branch is connected in parallel with each side flow channel.

5. A liquid cooling system for a liquid-cooled battery pack according to claim 4, characterized in that: The side liquid cooling plate is provided with an extension portion extending out of the battery module, the extension portion is provided with a side water inlet and a side water outlet, the side water inlet is connected to the water inlet liquid cooling pipeline, and the side water outlet is connected to the water outlet liquid cooling pipeline.

6. A liquid cooling system for a liquid-cooled battery pack according to claim 5, characterized in that: The orientations of the side water inlet and the side water outlet of the side liquid cooling plate are adaptively set according to the position of the side cooling plate in the liquid-cooled battery pack.

7. The liquid cooling system for a liquid-cooled battery pack according to claim 1, characterized in that: A plurality of isolated flow diversion islands arranged at equal intervals are arranged on the side liquid cooling plate. The flow diversion islands are arranged in the side flow channels. The flow resistance generated by the side flow channels in the forward flow direction through the flow diversion islands is smaller than the flow resistance generated in the reverse flow direction.

8. The liquid cooling system for a liquid-cooled battery pack according to claim 7, characterized in that: The diverter island is shaped like a water droplet with one end larger than the other. The diverter island includes arc edges, one large and one small, at both ends and a straight edge connecting the ends of the two arcs. The two straight edges are arranged obliquely. Along the forward flow direction of the side flow channel, the smaller end of the diverter island is located in the upstream position.

9. The liquid cooling system for a liquid-cooled battery pack according to claim 8, characterized in that: The side flow channel has two rows of diverter islands, and the two rows of diverter islands are staggered.

10. A liquid cooling system for a liquid-cooled battery pack according to any one of claims 7 to 9, characterized in that: The side flow channel is in a horizontal "U" shape, and the side water inlet is located above the side water outlet.

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