Cooling flow path structure, liquid cooling plate, and battery system

Abstract

This application provides a cooling channel structure, a liquid cooling plate, and a battery system, which includes a group of cooling channels, a channel inlet, and a channel outlet. The group of cooling channels includes at least one cooling pipeline, the flow direction of the liquid in the cooling pipeline is set as the first direction, the cooling pipeline is distributed in a tree shape from one side to the other side along the first direction, one side of the tree structure is the tree head, and the other side is the tree tail. The channel inlet communicates with the tree head side of the cooling pipeline in the group of cooling channels. The channel outlet communicates with the tree tail side of the cooling pipeline in the group of cooling channels.

Description

Technical Field

[0001] This application claims the priority of Chinese Patent Application No. 2023216687013 filed with the Chinese Patent Office on June 28, 2023, and Chinese Patent Application No. 2023107772736 filed with the Chinese Patent Office on June 28, 2023. The contents of the above applications are hereby incorporated by reference into this application in their entirety. This application relates to the technical field of batteries, and particularly to a cooling channel structure, a liquid cooling plate, and a battery system.

Background Art

[0002] With the rapid development of the electric vehicle field, the use of power batteries is becoming increasingly popular. Power batteries generate a large amount of heat during the charging and discharging process, causing the temperature inside the battery pack to rise, which affects the service life of the battery and may even lead to safety accidents due to thermal runaway. Therefore, the thermal management and thermal safety of power batteries have received increasing attention.

[0003] The requirements for rapid charging of cells in existing battery systems are becoming increasingly high, and it is difficult to control the heat generation of high current rate (high rate) cells. To enhance the cooling effect, existing battery systems usually have a liquid cooling plate installed on the upper or bottom surface of the cell. The liquid cooling plate is provided with a cooling channel.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Existing cooling channels are usually arranged symmetrically or designed in a coil shape. Such channels are very unsuitable for battery systems with relatively long battery modules, and the temperature difference between the left and right cells on the same horizontal channel is large, easily resulting in uneven cell cooling.

Means for Solving the Problems

[0005] In the first aspect, the present application provides a cooling channel structure including a group of cooling channels, a channel inlet, and a channel outlet. The group of cooling channels includes at least one cooling channel. The flow direction of the liquid in the cooling pipeline is set as the first direction. The cooling channels are distributed in a tree shape from one side to the other side along the first direction. The channel inlet communicates with the tree head side of the cooling pipeline in the group of cooling channels, and the channel outlet communicates with the tree tail side of the cooling pipeline in the group of cooling channels.

[0006] In the second aspect, the present application provides a liquid cooling plate including a cooling channel structure and a liquid cooling plate body. The group of cooling channels is bonded or fitted to one or both sides of the liquid cooling plate body.

[0007] In the third aspect, the present application provides a battery system including a battery case, a cell group, and a liquid cooling plate. The cell group and the liquid cooling plate body are arranged in the battery case, and the liquid cooling plate body is located on the upper surface or the bottom surface of the cell group.

Advantages of the Invention

[0008] 1. By designing the cooling pipeline into a tree structure, the number of cooling pipelines can be increased layer by layer, thereby effectively addressing the problem that the coolant in the cooling pipeline gradually rises. By increasing the heat exchange area, the heat exchange effect is improved, and the temperature difference of the overall heat exchange is made uniform.

[0009] 2. Since the number of layers and the number of cooling pipelines can be increased according to the actual situation, it can meet the comprehensive coverage of heat exchange and increase the heat exchange area.

[0010] 3. By combining the cooling pipeline and the liquid cooling plate, a heat exchange plate with uniform heat exchange can be formed, and the design of the cooling channel is flexible, which is beneficial to making the heat exchange temperature of the entire heat exchange plate uniform and reducing the temperature difference.

[0011] 4. By adopting a liquid cooling plate and a serpentine liquid cooling pipe, three-sided liquid cooling heat exchange is realized, the heat exchange efficiency is greatly improved, and the temperature control is improved.

Brief Description of the Drawings

[0012]

Figure 1

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Modes for Carrying Out the Invention

[0013] Conventional cooling pipelines are usually spiral curved pipes or serpentine pipes. The longer the time that the coolant in the cooling pipeline enters the cooling pipeline and flows and exchanges heat, the higher its temperature becomes. Therefore, the heat exchange effect on the heat generating device located in the latter half of the cooling pipeline is not good.

[0014] As shown in FIG. 1, Embodiment 1 of the present application discloses a cooling channel structure including a cooling channel group 1, a channel inlet 3, and a channel outlet 2. The cooling channel group 1 includes at least one cooling pipeline 11. The flow direction of the liquid in the cooling pipeline 11 is set as the first direction. It should be understood that since the first direction is the direction in which the proportion of the flow direction of the cooling pipeline 11 occupies a large part, there may be a partial turning structure in the cooling pipeline 11, but the main flow direction remains unchanged. In Embodiment 1, the first direction is the length direction of the cooling channel group, and the cooling pipeline 11 is distributed in a tree shape from one side to the other side along the first direction. The tree structure has at least two layers. When the tree structure has two layers, the tree structure includes two layers of a tree head 111 and a tree tail 113. When the tree structure has three or more layers, the tree structure includes a tree head 111, a tree trunk 112, and a tree tail 113. One side of the tree structure is the tree head 111, the other side is the tree tail 113, and the tree trunk 112 is located between the tree head 111 and the tree tail 113. The channel inlet 3 communicates with the tree head 111 side of the cooling pipeline 11 in the cooling channel group 1, and the channel outlet 2 communicates with the tree tail 113 side of the cooling pipeline 11 in the cooling channel group 1. The temperature of the coolant in the cooling pipeline 11 rises as the length of the pipeline increases. By designing the cooling pipeline 11 in the cooling channel group 1 to be distributed in a tree shape, the number of cooling pipelines 11 can be increased layer by layer. According to the area requiring heat exchange, the number of layers of the tree structure is increased to ensure that the heat exchange in the latter half of the cooling pipeline 11 is more intensive, thereby gradually increasing the contact area with the heat-generating member and effectively addressing the problem that the coolant in the cooling pipeline 11 gradually rises. By increasing the heat exchange area, the temperature difference between cells can be reduced, the temperature of the heat-generating member can be controlled within a reasonable range, the uniformity of heat exchange can be realized, which is beneficial for extending the service life of the heat-generating member.

[0015] In one embodiment, when the cooling channel group 1 includes only one cooling pipeline 11, the cooling pipeline 11 of the cooling pipeline 11 is connected to the flow path inlet 3, and the cooling pipeline 11 is collectively connected to the flow path outlet 2 as one pipeline on the tree tail 113 side. The coolant introduced into the flow path inlet 3 first flows through the tree head 111 structure of the cooling pipeline 11, then flows through the tree tail 113 structure of the cooling pipeline 11, and finally flows out from the flow path outlet 2 to realize the heat exchange effect of the coolant.

[0016] In one embodiment, when the cooling channel group 1 includes two or more cooling pipelines 11, each cooling channel is on the same horizontal plane, and each cooling pipeline 11 in the cooling channel group 1 is kept horizontal, so the cooling channel group 1 forms a cooling plane. The tree head 111 structure of each cooling pipeline 11 is connected to one inlet main pipe 5, and the inlet main pipe 5 communicates with the flow path inlet 3. The tree tail 113 structure of each cooling pipeline 11 is connected to one outlet main pipe 4, and the outlet main pipe 4 communicates with the flow path outlet 2. By arranging the inlet main pipe 5 and the outlet main pipe 4, each cooling pipeline 11 can be relatively fixed between the inlet main pipe 5 and the outlet main pipe 4 to form a plane. The coolant introduced into the flow path inlet 3 first flows into the inlet main pipe 5, then disperses into the tree head 111 structures of each cooling pipeline 11, then flows through the tree tail 113 structures of each cooling pipeline 11, and finally passes through the outlet main pipe 4 and flows out from the flow path outlet 2 to realize the heat exchange effect of the coolant.

[0017] In one embodiment, when the cooling channel group 1 includes two or more cooling pipelines 11, since each cooling channel is located in a different horizontal plane, the cooling channel group 1 can dissipate heat to a plurality of surfaces of the heat-generating object. Therefore, each cooling pipeline 11 in the cooling channel group 1 can be adaptively changed according to the surface shape of the heat-generating object. For example, when the heat-generating object is a cylinder, the inlet main pipe 5 is arranged along the circular circumference on one side of the cylinder, and the outlet main pipe 4 is arranged along the circular circumference on the other side of the cylinder. Each of the cooling pipelines 11 is arranged at an interval between the inlet main pipe 5 and the outlet main pipe 4. Each cooling pipeline 11 in the cooling channel group 1 is kept horizontal. The connection method between the cooling pipeline 11, the inlet main pipe 5, and the outlet main pipe 4 may be a vertical connection, or each cooling pipeline 11 may be wound in a coil shape along the side surface of the cylinder to present a certain angle so as to realize the heat exchange effect. When the heat-generating object is a prism, the inlet main pipe 5 is arranged along the outer periphery of the plane on one side of the prism, and the outlet main pipe 4 is arranged along the outer periphery of the plane on the other side of the prism. Each of the cooling pipelines 11 is arranged at an interval between the inlet main pipe 5 and the outlet main pipe 4. Each cooling pipeline 11 in the cooling channel group 1 is kept horizontal, thereby covering at least one side surface of the prism to realize the heat exchange effect. When the heat-generating object is a prism or a frustum of a cone, the inlet main pipe 5 and the outlet main pipe 4 are still arranged along the outer periphery of both end faces. Each of the cooling pipelines 11 is arranged at an interval between the inlet main pipe 5 and the outlet main pipe 4. At this time, not all of the cooling pipelines 11 are horizontal, thereby covering at least a part of the side surfaces of the prism or the frustum of a cone to realize the heat exchange effect.

[0018] The number of layers of the tree structure in the cooling pipeline 11 is preferably 2, 3, or 4, and the pipelines of each layer of the tree structure increase in a two-fold relationship. Therefore, the distance between the tree heads 111 between the respective cooling pipelines 11 requires at least the interval within the width range of the tree tail 113. Thereby, a smooth arrangement between the cooling pipelines 11 is ensured. Accordingly, the tree structure becomes a binary tree structure, and the branches of each layer of the tree structure are kept parallel to each other, preventing excessive diversion that causes the interval distance between the cooling pipelines 11 located on one side of the tree head 111 from being too far and reducing the heat exchange effect.

[0019] In one embodiment, when there are a plurality of the cooling pipelines 11 and they are located in the same plane, as the number of layers of the tree structure increases, the distance between the tree heads 111 becomes farther. Therefore, in order to ensure a larger heat exchange area on the horizontal plane of the cooling pipeline 11, a third surrounding pipe 8 is provided between the outlet main pipe 4 and the inlet main pipe 5. The third surrounding pipe 8 is located at the ends of the outlet main pipe 4 and the inlet main pipe 5 and at the edge of the cooling flow path group 1, so that supplementary heat exchange can be performed on the part where the tree head 111 cannot perform heat exchange, increasing the heat exchange area of the entire cooling flow path group 1. Also, in some embodiments, the flow path inlet 3 and the flow path outlet 2 usually need to be designed in the center to reduce the area occupied by the entire cooling pipeline group 11. Therefore, a first surrounding pipe 7 is provided on one side of the inlet main pipe 5, and a second surrounding pipe 6 is also provided on one side of the outlet main pipe 4. The third surrounding pipe 8 is located on the other side of the inlet main pipe 5 and the other side of the outlet main pipe 4. The first surrounding pipe 7 and the second surrounding pipe 6 are arranged around the edge on one side of the cooling flow path group 1. The end of the first surrounding pipe 7 communicates with the flow path inlet 3, and the end of the second surrounding pipe 6 communicates with the flow path outlet 2, whereby the flow path inlet 3 and the flow path outlet 2 are arranged in the center, reducing the volume occupied by the entire cooling flow path group 1 and increasing the heat exchange area.

[0020] As shown in FIG. 2, the present application also relates to a liquid cooling plate including a liquid cooling plate body 9 and any one of the above cooling channel structures. The cooling channel group 1 is bonded or fitted to one or both sides of the liquid cooling plate body 9. Thereby, the heat exchange area from one side to the other side of the liquid cooling plate gradually increases, corresponding to the problem that the temperature of the coolant in the cooling pipeline 11 on the cooling plate gradually rises. This is advantageous for equalizing the temperature of the liquid cooling plate from one side to the other side in the horizontal direction.

[0021] Note that the liquid cooling plate body 9 may have a coplanar flat plate structure and is used for heat exchange of a single surface of the heat source, or may have a non-coplanar bent plate structure and is used for heat exchange of at least two surfaces of the heat source. It is also possible to join a plurality of liquid cooling plates to form a cooling housing and use it for overall heat exchange of the heat source.

[0022] Referring to FIGS. 3 to 6, the present application also relates to a battery system including a battery case, a cell group, and a liquid cooling plate. In this embodiment, the liquid cooling plate body 9 is a coplanar flat plate. The cell group and the liquid cooling plate body 9 are arranged in the battery case. The liquid cooling plate body 9 is located on the upper surface or the bottom surface of the cell group, which is advantageous for heat exchange with respect to the upper surface or the bottom surface of the cell group and ensures uniform heat exchange of the cell group. The flow direction of the cooling pipeline 11 on the liquid cooling plate body 9 coincides with the length direction of the battery case, which is advantageous for realizing the arrangement of the tree structure and the uniform heat effect. Note that in other embodiments, the liquid cooling plate body 9 can also be joined to the six surfaces of the cell group to achieve overall heat exchange.

[0023] The cell group includes multiple rows of cells arranged linearly, and side liquid cooling plates 10 are provided on both sides of the cells in each row. The side liquid cooling plates 10 are attached to the cell side walls, and the side liquid cooling plates 10 communicate with the inside of the liquid cooling plate body 9. Each of the side liquid cooling plates 10 includes a liquid inlet 102 and a liquid outlet 101. The liquid inlets 102 of the side liquid cooling plates 10 are connected in series to form a liquid introduction pipeline 104, and the liquid outlets 101 of the side liquid cooling plates 10 are connected in series to form a liquid discharge pipeline 103. In some embodiments, a plurality of the liquid introduction pipelines 104 and liquid discharge pipelines 103 are provided and can be assembled at both ends of the side liquid cooling plates 10 respectively.

[0024] When injecting liquid, the cooling liquid is respectively sent through the shunt pipe 30 to each liquid introduction pipeline 104 and the flow path inlet 3 of the liquid cooling plate body 9, and after flowing through the side liquid cooling plates 10 and the liquid cooling plate body 9 respectively, it flows out from each liquid discharge pipeline 103 and the flow path outlet 2 of the liquid cooling plate body 9, and finally is discharged collectively through the collecting pipe 20. By combining the side liquid cooling plates 10 and the liquid cooling plate body 9, three-sided cooling on the upper surface or bottom surface of the cell and both sides of the cell can be realized, the heat exchange area between the cell and the cooling liquid is greatly increased, and when charging at a high current rate, the charging safety of the cell is improved. In this embodiment, since the cell is cylindrical, the side liquid cooling plate 10 adopts a serpentine liquid cooling plate, which is advantageous for attaching to the side wall surface of the cell and improves the heat exchange area. In other embodiments, the structure of the side liquid cooling plate 10 changes according to the shape change of the cell.

[0025] It should be noted that the above liquid injection direction can be changed to realize reverse liquid injection.

[0026] The number of cells covered by the tree structure of each layer in the cooling pipeline 11 in the liquid cooling plate body 9 is 6 to 9, thereby preventing the problem of uneven cooling caused by excessive attenuation of the heat exchange effect due to too many cells cooled in each layer. In this embodiment, the tree structure has three layers.

[0027] When the liquid cooling plate body 9 is located on the upper surface of the cell group, the cooling pipeline 11 performs contact heat exchange with the aluminum row above the cell. The punching liquid cooling plate body 9 at the upper part of the cell is in direct contact with the welded aluminum row above the cell. When charging at a high current rate, the aluminum row generates significant heat, and the upper liquid cooling plate body 9 can exchange heat with it. At the same time, since the aluminum row is welded to the cell terminal post, the cell is cooled.

[0028] To summarize the above, the cooling flow path structure, liquid cooling plate, and battery system provided by this application have the following technical effects. 1. By designing the cooling pipeline 11 in a tree structure, the number of cooling pipelines 11 can be increased layer by layer, thereby effectively addressing the problem that the coolant in the cooling pipeline 11 gradually rises. By increasing the heat exchange area, the heat exchange effect is improved, and the temperature difference across the entire heat exchange is equalized. 2. Since the number of layers and quantity of the cooling pipeline 11 can be increased according to the actual situation, comprehensive coverage of heat exchange can be achieved, and the heat exchange area can be increased. 3. By combining the cooling pipeline 11 and the liquid cooling plate, a heat exchange plate with uniform heat exchange can be formed, and the design of the cooling flow path is flexible, which is beneficial for equalizing the heat exchange temperature of the entire heat exchange plate and reducing the temperature difference. 4. By adopting the liquid cooling plate and the serpentine liquid cooling pipe, three-sided liquid cooling heat exchange is realized, the heat exchange efficiency is greatly improved, and the temperature control is improved.

Explanation of Reference Signs

[0029] 1. Cooling flow path group; 11. Cooling pipeline; 111. Tree head; 112. Tree trunk; 113. Tree tail; 2. Flow path outlet; 3. Flow path inlet; 4. Outlet main pipe; 5. Inlet main pipe; 6. Second surrounding pipe; 7. First surrounding pipe; 8. Third surrounding pipe; 9. Cooling plate body; 10. Side liquid cooling plate; 101. Liquid outlet; 102. Liquid inlet; 103. Liquid discharge pipeline; 104. Liquid introduction pipeline; 20. Manifold; 30. Diverging pipe

Claims

1. A cooling flow path structure including a cooling flow path group (1), a flow path inlet (3), and a flow path outlet (2), wherein the cooling flow path group (1) includes at least one cooling pipeline (11), the flow direction of the liquid in the cooling pipeline is set as the first direction, the cooling pipeline (11) is distributed in a tree shape from one side to the other side along the first direction, one side of the tree structure is a tree head (111), and the other side is a tree tail (113), the flow path inlet (3) communicates with the tree head (111) side of the cooling pipeline (11) in the cooling flow path group (1), the flow path outlet (2) communicates with the tree tail (113) side of the cooling pipeline (11) in the cooling flow path group (1), and the cooling flow path structure is characterized by this.

2. When the number of cooling pipelines (11) in the cooling flow path group (1) is two or more, an inlet main pipe (5) is connected to one side of the cooling flow path group (1), an outlet main pipe (4) is connected to the other side of the cooling flow path group (1), the flow path inlet (3) communicates with the inlet main pipe (5), and the flow path outlet (2) communicates with the outlet main pipe (4). The cooling flow path structure according to Claim 1 is characterized by this.

3. The cooling pipelines (11) in the cooling flow path group (1) are on the same horizontal plane, and each cooling pipeline (11) is arranged between the inlet main pipe (5) and the outlet main pipe (4) at intervals. The cooling flow path structure according to Claim 2 is characterized by this.

4. Among the cooling pipelines (11) in the cooling flow path group (1), at least two cooling pipelines (11) are not on the same plane, and each cooling pipeline (11) is arranged between the inlet main pipe (5) and the outlet main pipe (4) at intervals. The cooling flow path structure according to Claim 2 is characterized by this.

5. The cooling pipeline (11) includes at least a two-layer tree structure. When the tree structure has two or more layers, a tree trunk (112) is further included between the tree head (111) and the tree tail (113) of the tree structure. The cooling flow path structure according to any one of Claims 1 to 4 is characterized by this.

6. The tree structure is a binary tree structure, and the branches of the tree structure of each layer are kept parallel to each other. The cooling flow path structure according to Claim 5 is characterized by this.

7. On one side of the inlet main pipe (5), a first surrounding pipe (7) is further provided. On one side of the outlet main pipe (4), a second surrounding pipe (6) is further provided. Between the other side of the inlet main pipe (5) and the other side of the outlet main pipe (4), a third surrounding pipe (8) is further provided. The first surrounding pipe (7), the second surrounding pipe (6), and the third surrounding pipe (8) are all arranged to surround the edge of the cooling channel group (1). The cooling channel structure according to any one of claims 2 to 4, characterized in that.

8. A liquid cooling plate, comprising the cooling channel structure according to any one of claims 1 to 7 and a liquid cooling plate body (9), wherein the cooling channel group (1) is bonded or fitted to one or both sides of the liquid cooling plate body (9). A liquid cooling plate, characterized in that.

9. A battery system, comprising a battery case, a cell group, and the liquid cooling plate according to claim 8, wherein the cell group and the liquid cooling plate body (9) are arranged in the battery case, and the liquid cooling plate body (9) is located on the upper surface or the bottom surface of the cell group. A battery system, characterized in that.

10. The cell group includes a plurality of rows of cells arranged linearly, and side liquid cooling plates (10) are provided on both sides of the cells in each row. The side liquid cooling plates (10) are bonded to the cell side walls, and the side liquid cooling plates (10) communicate with the inside of the liquid cooling plate body (9). The battery system according to claim 9, characterized in that.

11. The flow direction of the cooling pipeline (11) on the liquid cooling plate body (9) is consistent with the length direction of the battery case. The battery system according to claim 10, characterized in that.

12. The number of cells covered by the tree structure of each layer is 6 to 9. The battery system according to claim 10, characterized in that.

13. When the liquid cooling plate body (9) is located on the upper surface of the cell group, the cooling pipeline (11) performs contact heat exchange with the aluminum row above the cells. The battery system according to claim 10, characterized in that.

14. The battery system according to claim 10, further comprising a manifold pipe (20) and a shunt pipe (30), wherein the shunt pipe (30) is used to divert the coolant into the side liquid cooling plate (10) and the liquid cooling plate body (9), and the manifold pipe (20) is used to collectively discharge the coolant in the side liquid cooling plate (10) and the liquid cooling plate body (9).

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