Liquid cooling system and battery pack

Abstract

Provided in the present application are a liquid cooling system and a battery pack. The liquid cooling system comprises a liquid cooling plate (2) and a connecting pipe (1), wherein one of the liquid cooling plate (2) and the connecting pipe (1) is provided with a first pipe joint (121), the other one thereof is provided with a second pipe joint (21) that can be inserted into the first pipe joint (121), and a sealing assembly (3) is provided at a fit portion of the two pipe joints; the sealing assembly (3) comprises a flexible sealing sleeve (31) and a rigid support ring (32) embedded into the flexible sealing sleeve (31), the flexible sealing sleeve (31) being provided with an insertion hole (311) allowing the second pipe joint (21) to be inserted therein; the outer side wall of the flexible sealing sleeve (31) is in sealing fit with the inner wall of the first pipe joint (121); and at least part of the inner wall of the insertion hole (311) can be in sealing fit with the outer wall of the second pipe joint (21).

Description

Liquid cooling system and battery pack

[0001] This application claims priority to Chinese Patent Application No. 202423318441.4, filed with the Chinese Patent Office on December 31, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery technology, specifically to a liquid cooling system and a battery pack. Background Technology

[0003] A battery pack typically includes a housing and battery cell groups housed within the housing. Multiple battery cell groups are arranged in parallel and spaced apart, and each battery cell group consists of multiple cylindrical cells arranged sequentially. Since temperature directly affects the capacity, charge and discharge efficiency, safety, and lifespan of the cylindrical cells, a liquid cooling system configured to heat or dissipate heat from the cylindrical cells is also required within the battery pack.

[0004] In related technologies, for cylindrical battery cells, most methods use serpentine liquid cooling plates that contact the sides of the cylindrical battery cells for thermal management. Serpentine liquid cooling plates are installed on both sides of multiple battery cell groups. The curvature of the curved surface of the serpentine liquid cooling plate is matched with the curvature of the side of the cylindrical battery cell to increase the contact area between the two and improve the cooling efficiency.

[0005] Because cylindrical battery cells typically have a small diameter, the arrangement of the serpentine liquid cooling plates is too compact, and there are assembly errors and material tolerances, resulting in poor sealing reliability of the water circuit connection between the serpentine liquid cooling plates. Summary of the Invention

[0006] In a first aspect, embodiments of this application provide a liquid cooling system, including a liquid cooling plate and a connecting pipe. One of the liquid cooling plate and the connecting pipe has a first pipe connector, and the other has a second pipe connector configured to be inserted into the first pipe connector. The mating portion of the second pipe connector and the first pipe connector has a sealing assembly, the sealing assembly comprising:

[0007] A flexible sealing sleeve is accommodated within the first pipe joint. The flexible sealing sleeve has an insertion hole extending through its thickness direction. The outer wall of the flexible sealing sleeve is in sealing engagement with the inner wall of the first pipe joint. At least a portion of the inner wall of the insertion hole is configured to be in sealing engagement with the outer wall of the second pipe joint.

[0008] A rigid support ring is embedded in the flexible sealing sleeve.

[0009] Secondly, embodiments of this application provide a battery pack, including a housing, a battery cell assembly, and a liquid cooling system as described in any of the preceding claims. Multiple battery cell assemblies are arranged at intervals along a first direction, and the liquid cooling plates are provided on both sides of the multiple battery cell assemblies. The gaps between the battery cell assemblies, the liquid cooling system, and the housing are filled with potting adhesive. Attached Figure Description

[0010] Figure 1 shows a partial structural schematic diagram of the battery pack provided in an embodiment of this application.

[0011] Figure 2 shows a schematic diagram of the battery pack with concealed casing and filling adhesive provided in an embodiment of this application.

[0012] Figure 3 shows an exploded view of two adjacent connecting pipes provided in an embodiment of this application.

[0013] Figure 4 shows a cross-sectional view of two adjacent connecting pipes in the connection state provided in this embodiment.

[0014] Figure 5 shows a partial structural schematic diagram of the liquid cooling system and battery pack provided in the embodiments of this application.

[0015] Figure 6 shows a partial cross-sectional schematic diagram of the liquid cooling system provided in an embodiment of this application.

[0016] Figure 7 shows a partial structural schematic diagram of the connecting pipe provided in an embodiment of this application.

[0017] Figure label:

[0018] 100. Housing; 200. Cylindrical battery cell; 300. Liquid cooling system; 400. Filling adhesive;

[0019] 10. Main pipe; 1. Connecting pipe; 11. Main pipe; 12. Branch pipe; 121. First pipe joint; 1211. Limiting groove; 13. Elastic buckle; 131. First limiting surface; 14. Snap protrusion; 141. Second limiting surface;

[0020] 2. Liquid cooling plate; 21. Second pipe joint; 211. Baffle;

[0021] 3. Sealing assembly; 31. Flexible sealing sleeve; 311. Insertion hole; 312. Embedded groove; 313. Deformation buffer groove; 32. Rigid support ring; 33. Sealing gasket. Detailed Implementation

[0022] Figure 1 shows a partial structural schematic diagram of the battery pack provided in an embodiment of this application. As shown in Figure 1, the battery pack includes a housing 100, a cell group, and a liquid cooling system 300. Multiple cell groups are arranged at intervals along a first direction. Each cell group consists of multiple cylindrical cells 200 arranged along a second direction. The liquid cooling system 300 is configured to cool the cylindrical cells 200 in the multiple cell groups to provide a suitable ambient temperature for the cylindrical cells 200, thereby ensuring the capacity, charge / discharge efficiency, safety, and service life of the cylindrical cells 200.

[0023] Furthermore, the gaps between the cell assembly, the liquid cooling system 300, and the housing 100 are filled with potting adhesive 400. This adhesive 400 secures the cell assembly and the liquid cooling system 300 within the housing 100, while also providing stability and improving the overall safety of the battery pack. For example, the potting adhesive 400 can be expanding foam. Expanding foam not only enhances the structural strength of the entire battery pack and provides thermal runaway insulation between the cylindrical cells 200, preventing heat propagation, but also ensures the reliability of the liquid cooling system 300.

[0024] Figure 2 shows a schematic diagram of the hidden housing 100 and the filling adhesive 400 of the battery pack provided in the embodiment of this application. As shown in Figure 2 in conjunction with Figure 1, the liquid cooling system 300 includes a liquid cooling plate 2 and a main pipe 10. Liquid cooling plates 2 are provided on both sides of multiple sets of battery cells. Multiple liquid cooling plates 2 are connected in parallel through the main pipe 10, which can greatly reduce the fluid resistance of the liquid cooling system 300 and improve the cooling effect.

[0025] In this embodiment, the liquid cooling plate 2 is serpentine in shape. The curvature of the curved surface of the serpentine liquid cooling plate 2 is adapted to the curvature of the side of the cylindrical battery cell 200 to increase the contact area between the two, resulting in high cooling efficiency and low voltage drop of the liquid cooling system 300, which can cope with the heat generated by higher fast charging rates.

[0026] The main pipe 10 is composed of multiple connecting pipes 1 spliced ​​together. When assembling the liquid cooling system 300, the connecting pipes 1 can be assembled with the liquid cooling plate 2 first, and then the connecting pipes 1 can be assembled with each other, which can improve the assembly efficiency of the liquid cooling system 300.

[0027] Figure 3 shows an exploded view of two adjacent connecting pipes 1 provided in an embodiment of this application. Figure 4 shows a cross-sectional view of two adjacent connecting pipes 1 in a connected state provided in this embodiment. As shown in Figures 3 and 4, each connecting pipe 1 includes a main pipe 11 and a branch pipe 12 connected to the main pipe 11 at an angle. Two adjacent connecting pipes 1 are quickly connected by a plug-in connection between the main pipes 11. The branch pipe 12 is configured to connect to the liquid cooling plate 2. For example, the branch pipe 12 can be connected perpendicularly to the main pipe 11, or it can be connected to the main pipe 11 at an acute or obtuse angle. The design can be customized as needed and is not limited here.

[0028] In this embodiment, a single connecting pipe 1 may have one branch pipe 12 or two branch pipes 12, which can improve the flexibility of assembly between connecting pipes 1 and reduce the probability that the main pipe 10 and the liquid cooling plate 2 cannot be assembled due to assembly errors or processing errors.

[0029] Of the two adjacent main pipes 11, one has an elastic snap 13 on its outer peripheral wall, and the other has a snap protrusion 14 that engages with the elastic snap 13. A sealing ring is also provided at the mating part between the two main pipes 11, which enables a sealed connection between them and prevents coolant leakage from the connection point. The outer wall of one of the main pipes 11 has a groove to accommodate the sealing ring, allowing for its positioning and installation, preventing misalignment during the insertion of the two main pipes 11, and ensuring the sealing effect of the sealing ring.

[0030] Furthermore, the elastic buckle 13 has a first limiting surface 131, and the latching protrusion 14 has a second limiting surface 141 that abuts against the first limiting surface 131. The distance L1 between the first limiting surface 131 and the connection point between the elastic buckle 13 and the corresponding main pipe 11 is greater than the distance L2 between the second limiting surface 141 and the end of the corresponding main pipe 11. This arrangement allows adjacent main pipes 11 to have a degree of freedom along the first direction, reducing the probability that adjacent connecting pipes 1 cannot be assembled with their corresponding liquid cooling plates 2 due to processing errors.

[0031] In one embodiment, the difference between L1 and L2 can be any value between 1mm and 20mm to compensate for the assembly error between the branch pipe 12 of the connecting pipe 1 and the corresponding liquid cooling plate 2, so as to facilitate the rapid and accurate assembly of the liquid cooling system 300 and improve the assembly effect and assembly efficiency.

[0032] The protrusion 14 can be annular to facilitate limiting engagement with any number of elastic buckles 13. In this embodiment, there are two elastic buckles 13, which are symmetrically connected to the outer wall of the connecting pipe 1. While ensuring the connection strength of the two connecting pipes 1, the two elastic buckles 13 can reduce the processing difficulty and material cost.

[0033] Figure 5 shows a partial structural schematic diagram of the liquid cooling system 300 and the cell assembly provided in this embodiment. Figure 6 shows a partial cross-sectional schematic diagram of the liquid cooling system 300 provided in this embodiment. As shown in Figures 5 and 6, the flow channels within the liquid cooling plate 2 are U-shaped, with one arm of the U-shape serving as the inlet flow channel and the other arm as the outlet flow channel. The liquid cooling plate 2 has two pipe connectors at the same end, which are respectively connected to the inlet and outlet flow channels. Designing the inlet and outlet pipe connectors of the liquid cooling plate 2 on the same side of the liquid cooling plate 2 saves space within the housing 100 occupied by the liquid cooling system 300, improving the space utilization rate of the battery pack. Furthermore, the U-shaped flow channels within a single liquid cooling plate 2 can also neutralize the temperature of the coolant within the single liquid cooling plate 2, reducing the temperature difference between different cylindrical cells 200 along the length of the single liquid cooling plate 2.

[0034] There are two main pipes 10. One main pipe 10 (a branch pipe 12 of the connecting pipe 1) is connected to one pipe joint of the liquid cooling plate 2 and is configured to allow coolant to flow into the liquid cooling plate 2. The other main pipe 10 (a branch pipe 12 of the connecting pipe 1) is connected to another pipe joint of the liquid cooling plate 2 and is configured to allow coolant to flow out of the liquid cooling plate 2, thereby realizing the circulation of coolant within the liquid cooling plate 2 and improving the thermal management efficiency of the liquid cooling plate 2. To facilitate the connection between the branch pipe 12 and the pipe joint of the liquid cooling plate 2, the branch pipe 12 also has a pipe joint. One of the pipe joints of the branch pipe 12 and the pipe joint of the liquid cooling plate 2 is inserted into the other to achieve a quick insertion connection. A sealing component 3 is provided at the mating part between the pipe joints. This sealing component 3 not only improves the sealing performance between the two pipe joints but also prevents the pipe joints from breaking due to excessive insertion force.

[0035] It is understandable that the connection scheme between the pipe connector of branch pipe 12 and the pipe connector of liquid cooling plate 2 can be either inserting the pipe connector of branch pipe 12 into the pipe connector of liquid cooling plate 2, or inserting the pipe connector of liquid cooling plate 2 into the pipe connector of branch pipe 12. For ease of description, the pipe connector into which another pipe connector is inserted is referred to as the first pipe connector 121, and the pipe connector into the first pipe connector 121 is referred to as the second pipe connector 21.

[0036] Figure 7 shows a partial structural schematic diagram of the connecting pipe 1 provided in an embodiment of this application. As shown in Figure 7 in conjunction with Figure 6, the sealing assembly 3 includes a flexible sealing sleeve 31 and a rigid support ring 32. The flexible sealing sleeve 31 is housed within the first pipe joint 121, and the outer wall of the flexible sealing sleeve 31 is in a sealing fit with the inner wall of the first pipe joint 121. The flexible sealing sleeve 31 has an insertion hole 311 extending through its thickness direction. The second pipe joint 21 is inserted into the insertion hole 311, and at least a portion of the inner wall of the insertion hole 311 is capable of sealing fit with the outer wall of the second pipe joint 21. The flexible sealing sleeve 31 also has an embedding groove 312 circumferentially disposed around the insertion hole 311, and the rigid support ring 32 is housed within the embedding groove 312. When the second pipe connector 21 is inserted into the insertion hole 311 of the flexible sealing sleeve 31 inside the first pipe connector 121, the elastic deformation of the flexible sealing sleeve 31 achieves a sealed connection between the two. The rigid support ring 32 supports and limits the second pipe connector 21 to prevent the first pipe connector 121 from breaking due to excessive insertion force.

[0037] In other words, the flexible sealing sleeve 31 forms an interference fit with the inner wall of the first pipe joint 121 and the outer wall of the second pipe joint 21 to achieve a sealing effect. The sealing strength can be guaranteed by controlling the amount of interference fit between the flexible sealing sleeve 31 and the inner wall of the first pipe joint 121 and the amount of interference fit between the insertion hole 311 and the outer wall of the second pipe joint 21. In addition, the flexible sealing sleeve 31 can also absorb the dimensional tolerances of the second pipe joint 21 and the first pipe joint 121 at different angles in the circumferential direction to ensure the sealing effect. The rigid support ring 32 is configured to support the flexible sealing sleeve 31 and can also limit the second pipe joint 21 to prevent the flexible sealing sleeve 31 from deforming excessively and squeezing the first pipe joint 121. By controlling the hardness of the rigid support ring 32, the connection strength and sealing strength between the first pipe joint 121 and the second pipe joint 21 can be guaranteed, and the flexible sealing sleeve 31 can be prevented from being pulled out and crushed.

[0038] In this embodiment, the flexible sealing sleeve 31 can be made of any of the following materials: EPDM (Ethylene-propylene-diene Monomer), TPE (Thermoplastic Elastomer), or TPU (Thermoplastic Polyurethanes), as long as it can achieve a sealing effect; there are no restrictions on its material. The rigid support ring 32 can be made of any of the following materials: aluminum or steel, as long as it can improve the sealing strength and prevent pull-out and crushing during expansion; further examples will not be provided here.

[0039] The flexible sealing sleeve 31 and the rigid support ring 32 can be integrally molded by injection molding by embedding a rigid material, or the flexible sealing sleeve 31 and the rigid support ring 32 can be processed separately first, and then the rigid support ring 32 can be inserted into the embedding groove 312 of the flexible sealing sleeve 31.

[0040] The insertion hole 311 is conical, and its diameter gradually decreases along the insertion direction of the second pipe connector 21. The maximum diameter of the insertion hole 311 is greater than the diameter of the insertion part of the second pipe connector 21, while the minimum diameter of the insertion hole 311 is smaller than the diameter of the insertion part of the second pipe connector 21. This ensures that the second pipe connector 21 can be smoothly inserted into the insertion hole 311, and part of the inner wall of the insertion hole 311 can be interference-fitted with the outer wall of the second pipe connector 21 to improve the sealing performance of the mating parts and enhance the sealing effect.

[0041] When the second pipe connector 21 is inserted into the insertion hole 311, the flexible sealing sleeve 31 will be subjected to compressive force. In order to prevent the flexible sealing sleeve 31 from cracking due to excessive compressive force, the end face of the flexible sealing sleeve 31 facing away from the second pipe connector 21 has a deformation buffer groove 313 arranged around the insertion hole 311. The deformation buffer groove 313 can absorb the deformation of the flexible sealing sleeve 31 caused by the compressive force.

[0042] In this embodiment, the longitudinal cross-sectional shape of the deformable buffer groove 313 is V-shaped. This V-shaped deformable buffer groove 313 is not only easy to process, but also has a good energy absorption effect.

[0043] The outer peripheral wall of the second pipe connector 21 is provided with a baffle 211 extending radially therefrom. The baffle 211 can be inserted into the first pipe connector 121, and the diameter of the baffle 211 is larger than the maximum diameter of the insertion hole 311. The baffle 211 can not only limit the insertion depth of the second pipe connector 21, but also prevent the potting adhesive 400 from flowing into the first pipe connector 121, ensuring the unobstructed flow of the internal channels of the liquid cooling system 300; it can also increase the bonding area between the baffle and the potting adhesive 400, and improve the fixing effect of the potting adhesive 400 on the connection part.

[0044] The sealing assembly 3 also includes a sealing gasket 33. The inner wall of the first pipe joint 121 has a limiting groove 1211 for accommodating the sealing gasket 33. A portion of the sealing gasket 33 is accommodated within the limiting groove 1211, and the sealing gasket 33 is located between the baffle 211 and the flexible sealing sleeve 31. The sealing gasket 33 can prevent the baffle 211 from directly acting on the flexible sealing sleeve 31, and prevent the baffle 211 from exerting a large compressive force on the flexible sealing sleeve 31.

Claims

1. A liquid cooling system comprising a liquid cooling plate (2) and a connecting pipe (1), one of the liquid cooling plate (2) and the connecting pipe (1) having a first pipe connector (121), and the other having a second pipe connector (21) configured to be inserted into the first pipe connector (121), the mating portion of the second pipe connector (21) and the first pipe connector (121) having a sealing assembly (3), the sealing assembly (3) comprising: A flexible sealing sleeve (31) is housed within the first pipe joint (121). The flexible sealing sleeve (31) has an insertion hole (311) extending through its thickness direction. The outer wall of the flexible sealing sleeve (31) is sealed to the inner wall of the first pipe joint (121). At least a portion of the inner wall of the insertion hole (311) is configured to seal to the outer wall of the second pipe joint (21). A rigid support ring (32) is embedded in the flexible sealing sleeve (31).

2. The liquid cooling system of claim 1, wherein, The flexible sealing sleeve (31) also has an embedding groove (312) circumferentially disposed around the insertion hole (311), and the rigid support ring (32) is accommodated in the embedding groove (312).

3. The liquid cooling system of claim 1, wherein, The insertion hole (311) is conical, and the diameter of the insertion hole (311) gradually decreases along the insertion direction of the second pipe connector (21). The maximum diameter of the insertion hole (311) is greater than the diameter of the insertion part of the second pipe connector (21), and the minimum diameter of the insertion hole (311) is less than the diameter of the insertion part of the second pipe connector (21).

4. The liquid cooling system of claim 3, wherein, The flexible sealing sleeve (31) has a deformation buffer groove (313) around the end face opposite to the second pipe joint (21) surrounding the insertion hole (311).

5. The liquid cooling system of claim 1, wherein, The outer peripheral wall of the second pipe connector (21) is provided with a baffle (211) extending in its radial direction. The baffle (211) is configured to be inserted into the first pipe connector (121), and the diameter of the baffle (211) is greater than the maximum diameter of the insertion hole (311).

6. The liquid cooling system of claim 5, wherein, The sealing assembly (3) further includes a sealing gasket (33), the inner wall of the first pipe joint (121) has a limiting groove (1211), a portion of the sealing gasket (33) is accommodated in the limiting groove (1211), and the sealing gasket (33) is located between the baffle (211) and the flexible sealing sleeve (31).

7. The liquid cooling system according to any one of claims 1-6 further includes a main pipe (10) formed by at least two sequentially connected connecting pipes (1), each connecting pipe (1) including a main pipe (11) and a branch pipe (12) connected to the main pipe (11) at an angle, the main pipe (11) of one of the two adjacent connecting pipes (1) is inserted into the main pipe of the other connecting pipe (1), and the outer peripheral wall of the main pipe (11) of one of the connecting pipes (1) has an elastic buckle (13), the outer peripheral wall of the main pipe (11) of the other connecting pipe has a snap protrusion (14) that engages with the elastic buckle (13), and the branch pipe (12) has a first pipe joint (121) or a second pipe joint (21).

8. The liquid cooling system of claim 7, wherein, The elastic buckle (13) has a first limiting surface (131), and the buckle protrusion (14) has a second limiting surface (141) that abuts against the first limiting surface (131). The distance L1 between the first limiting surface (131) and the connection part between the elastic buckle (13) and the corresponding main tube (11) is greater than the distance L2 between the second limiting surface (141) and the end of the corresponding main tube (11).

9. The liquid cooling system of claim 7, wherein, Two main pipes (10) are provided, one of which is configured to allow coolant to flow into the liquid cooling plate (2), and the other is configured to allow coolant to flow out of the liquid cooling plate (2).

10. A battery pack, comprising a housing (100), a battery cell assembly, and a liquid cooling system as described in any one of claims 1-9, wherein a plurality of battery cell assemblies are arranged at intervals along a first direction, and the liquid cooling plates (2) are provided on both sides of the plurality of battery cell assemblies, and the gaps between the battery cell assemblies, the liquid cooling system, and the housing (100) are filled with potting adhesive (400).

Images