Module structure for cooling square battery pack and preventing thermal runaway propagation

Abstract

The invention discloses a module structure for cooling a square battery pack and preventing thermal runaway propagation, comprising: a plurality of square batteries arranged side by side to form a battery pack; the heat dissipation assemblies are placed between every two adjacent square batteries and comprise heat insulation materials and heat dissipation fins distributed on the two sides of the heat insulation materials, a plurality of low-melting-point alloys are distributed in the heat insulation materials, the two ends of the low-melting-point alloys are attached to the heat dissipation fins, and the heat dissipation fins are attached to the square batteries; and the cooling separator is used for supporting and placing the battery pack and the heat dissipation assembly, cooling liquid is distributed in the cooling separator, and the heat dissipation fins penetrate through the outer surface of the cooling separator to be in contact with the cooling liquid. According to the invention, heat dissipation can be carried out through the heat dissipation fins in contact with the square battery, heat conduction can be carried out on the heat dissipation fins in contact with the low-melting-point alloy through the low-melting-point alloy, so that the heat dissipation capability is improved, and the low-melting-point alloy can be molten when the temperature of the battery is too high, so that the low-melting-point alloy is out of contact with the heat dissipation fins on two sides; and propagation of thermal runaway behaviors is prevented.

Description

Technical Field

[0001] The present invention belongs to the field of thermal management of power batteries, and in particular relates to a module structure for dissipating heat from a square battery pack and preventing the spread of thermal runaway. Background Art

[0002] Energy transformation and new energy technologies have made great progress. Fields such as electric vehicles and energy storage power stations are showing a rapid growth trend. The energy density and range of power batteries have also been significantly improved, resulting in more and more heat generated by the battery during the charging and discharging process. In addition, due to the limitation of battery pack space, if the heat dissipation effect is not good, when the battery temperature exceeds its own tolerance temperature range, the battery is prone to thermal runaway, and even causes thermal runaway of the entire battery pack, eventually leading to fire and explosion accidents in new energy vehicles and energy storage power stations.

[0003] At present, a lot of research has been carried out on battery thermal management and thermal runaway protection. However, in practical applications, how to effectively integrate thermal management technology and thermal runaway prevention mechanism into the battery system to ensure that the battery pack can work stably and reliably is a challenging task. Summary of the invention

[0004] The purpose of the present invention is to overcome the above problems existing in the prior art and to provide a module structure for heat dissipation of square battery packs and prevention of thermal runaway propagation, which can not only achieve the effect of enhanced heat dissipation during the charging and discharging process of the battery pack, but also prevent the thermal runaway from propagating to adjacent battery packs when thermal runaway occurs in a single battery, and effectively integrate the battery pack thermal management technology and thermal runaway prevention mechanism into the battery system, effectively improving the performance and life of the battery pack and reducing the occurrence of fire risk accidents.

[0005] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0006] A module structure for dissipating heat from a square battery pack and preventing the spread of thermal runaway, comprising:

[0007] Several square batteries are arranged side by side to form a battery pack;

[0008] Several heat dissipation components are placed between two adjacent square batteries, including heat insulation materials and heat dissipation fins distributed on both sides of the heat insulation materials, wherein several low-melting-point alloys are distributed in the heat insulation materials, and both ends of the low-melting-point alloys are bonded to the heat dissipation fins, and the heat dissipation fins are bonded to the square batteries;

[0009] The cooling insulator is used to support and place the battery pack and the heat dissipation component. Coolant is distributed inside, and the heat dissipation fins pass through the outer surface of the cooling insulator and contact with the coolant.

[0010] Further, the cooling isolation member comprises a cooling plate and an isolation plate, wherein:

[0011] The isolation plate is used to support and place the battery pack and the heat dissipation component, and to isolate the battery pack from the cooling plate. The surface is provided with a plurality of plug-in hole groups corresponding to the heat dissipation component, and the plug-in hole group includes two plug-in through holes adapted to the heat dissipation fins;

[0012] The surface of the cooling plate is evenly distributed with plug-in grooves corresponding to the plug-in through holes, and the plug-in groove ports are connected to S-shaped flow channels, and the two ends of the S-shaped flow channel are respectively provided with a flow channel inlet and a flow channel outlet connected to the outside.

[0013] Furthermore, the gap between the heat dissipation fins and the square battery is filled with heat conductive material.

[0014] Further, the melting point of the low melting point alloy is lower than the maximum rated temperature of the battery pack.

[0015] Furthermore, the melting point of the low melting point alloy is 80-120 degrees Celsius.

[0016] Furthermore, the heat dissipation fins are connected to the plug-in through holes and the plug-in slots by welding.

[0017] Furthermore, the cooling isolation member is an independent cooling support plate, a flow channel hole is provided in the middle of the cooling support plate, coolant is distributed in the flow channel hole, and the heat dissipation fins pass through the outer surface of the cooling support plate and contact the coolant in the flow channel hole.

[0018] Furthermore, the heat dissipation fins are connected to the cooling support plate by welding.

[0019] Furthermore, it also includes an assembly unit for establishing a connection between two battery packs, the assembly unit includes a heat dissipation connection component, an isolation connection plate, and a cooling connection plate, wherein:

[0020] A heat dissipation connection assembly, used to connect two battery packs, comprising a heat-insulating connection material and heat-dissipating connection fins distributed on both sides of the heat-insulating connection material, wherein the heat-insulating connection material has the same structure as the heat-insulating material, and the heat-dissipating connection fins have the same structure as the heat-dissipating fins;

[0021] The isolation connection plate is used to support and place the heat-insulating connection material and isolate the heat-insulating connection material from the cooling connection plate, and first plug-in grooves adapted to the heat dissipation fins are symmetrically arranged on both sides of the surface;

[0022] Second plug-in grooves that are compatible with the heat dissipation fins are symmetrically provided on both sides of the surface of the cooling connection plate, a central flow channel is provided in the middle of the surface of the cooling connection plate, and both ends of the central flow channel are provided with an assembly inlet and an assembly outlet that are respectively connected to the second plug-in grooves, and L-shaped cooling plugs are provided at the outer ports of the assembly inlet and the assembly outlet, and the two cooling plugs are respectively plugged and connected to the flow channel inlet and the flow channel outlet.

[0023] Furthermore, the cooling connection plate is connected to the cooling plate via fasteners, wherein:

[0024] The fastener comprises a fastening plate and two limiting guide blocks symmetrically arranged on the inner surface of the fastening plate, a fastening through hole is arranged between the two limiting guide blocks, and a waist-shaped groove is arranged on the outer side of the limiting guide block; a first fastening bolt connected to the cooling connecting plate is installed in the fastening through hole, and a second fastening bolt connected to the cooling plate is installed in the waist-shaped groove; the limiting guide block comprises a first guiding inclined surface connected to the surface of the fastening plate, and an obtuse angle is formed between the first guiding inclined surface and the surface of the fastening plate;

[0025] First fastening screw holes matching with the first fastening bolts are symmetrically arranged at both ends of the cooling connection plate;

[0026] Second fastening screw holes matching with the second fastening bolts are arranged around the side of the cooling plate, a limiting guide groove matching with the limiting guide block is arranged between the second fastening screw hole and the corner of the cooling plate, and a second guiding inclined surface slidingly contacting with the first guiding inclined surface is arranged on the inner wall of the limiting guide groove.

[0027] The beneficial effects of the present invention are:

[0028] (1) In the battery module of the present invention, a low melting point alloy is placed in the heat insulation material between the two heat sinks. The low melting point alloy can conduct heat between the two heat sinks. When the temperature of a battery is too high, it can not only dissipate heat through the heat sink in contact with it, but also conduct heat to the heat sink in contact with it through the low melting point alloy, thereby improving the heat dissipation capacity.

[0029] (2) When the battery temperature rises too high and the heat dissipation capacity is insufficient, causing the battery temperature to be too high and thermal runaway to occur, the low-melting-point alloy will melt and then melt into the insulation material, losing contact with the heat dissipation fins on both sides, resulting in the heat being unable to spread to the surrounding area, thereby preventing the spread of thermal runaway behavior.

[0030] (3) The square batteries use a sandwich structure of "battery-heat sink-insulating material-heat sink-battery". There are two heat sinks between the two batteries to dissipate heat, which achieves the effect of enhanced heat dissipation. There is also a piece of insulation material between the two heat sinks to prevent thermal runaway.

[0031] (4) The isolation plate isolates the sandwich structure from the cooling plate, ensuring the safe operation of the battery pack. At the same time, the heat dissipation fins pass through the rectangular holes on the isolation plate to fix the sandwich structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0033] Figure 1 is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0034] Figure 2 is a structural explosion diagram of Embodiment 1 of the present invention;

[0035] Figure 3 It is a schematic diagram of a partial structure of Embodiment 1 of the present invention;

[0036] Figure 4 is an exploded view of a local structure of Example 1 of the present invention;

[0037] Figure 5 It is a schematic diagram of a partial structure of Embodiment 1 of the present invention;

[0038] Figure 6 It is a schematic diagram of a partial structure of Embodiment 1 of the present invention;

[0039] Figure 7 is a schematic structural diagram of Embodiment 2 of the present invention;

[0040] Figure 8 is a schematic diagram of the assembly structure of Example 3 of the present invention;

[0041] Fig. 9 is a schematic diagram of the structure of Embodiment 3 of the present invention;

[0042] Fig.10 is an exploded view of a local structure of Embodiment 3 of the present invention;

[0043] Fig.11 is a partial structural diagram of embodiment 3 of the present invention;

[0044] Fig.12 is an exploded view of a local structure of Embodiment 3 of the present invention;

[0045] Fig.13 It is a partial structural cross-sectional view of embodiment 3 of the present invention. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] In the description of the present invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inside", "all around" and the like indicating orientation or positional relationship are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the components or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0048] Example 1

[0049] like Figure 1-6 A module structure for heat dissipation of a square battery pack and preventing the spread of thermal runaway is shown, comprising:

[0050] A plurality of square batteries 1 are arranged side by side to form a battery pack;

[0051] Several heat dissipation components are placed between two adjacent square batteries 1, including a heat insulation material 3 and heat dissipation fins 2 distributed on both sides of the heat insulation material 3, a number of low melting point alloys 6 are distributed in the heat insulation material 3, both ends of the low melting point alloy 6 are attached to the heat dissipation fins 2, and the heat dissipation fins 2 are attached to the square battery 1, so as to facilitate the transfer of the generated heat and prevent the spread of battery thermal runaway;

[0052] The cooling isolation member is used to support and place the battery pack and the heat dissipation component, and coolant is distributed inside. The heat dissipation fins 2 pass through the outer surface of the cooling isolation member and contact with the coolant.

[0053] A sandwich structure of "square battery 1 - heat sink fin 2 - insulation material 3 - heat sink fin 2 - square battery 1" is formed between square batteries 1, so that when the temperature of a square battery 1 is too high, the heat is transferred to the heat sink fin 2, and the heat sink fin 2 then transfers the heat to the contacting heat sink fin 2 through the low melting point alloy 6, thereby achieving the effect of enhanced heat dissipation.

[0054] The low melting point alloy 6 filled in the thermal insulation material 3, when a square battery 1 has thermal runaway due to excessive temperature, the high temperature is transferred to the low melting point alloy 6, causing the low melting point alloy 6 to melt in the thermal insulation material 3, and the melted low melting point alloy 6 is out of contact with the heat sink fins 2. The thermal insulation material 3 isolates the square battery 1 in thermal runaway from the square battery 1 in normal operation.

[0055] The cooling isolation member includes a cooling plate 4 and an isolation plate 5, wherein:

[0056] The isolation plate 5 is used to support and place the battery pack and the heat dissipation component, and to isolate the battery pack from the cooling plate 4. A plurality of plug-in hole groups corresponding to the heat dissipation component are distributed on the surface. The plug-in hole group includes two plug-in through holes 51 adapted to the heat dissipation fins 2. The plug-in through holes 51 are rectangular holes.

[0057] The surface of the cooling plate 4 is uniformly provided with plug-in grooves 41 corresponding to the plug-in through holes 51 , and the ends of the plug-in grooves 41 are connected with S-shaped flow channels 42 , and both ends of the S-shaped flow channel 42 are provided with a flow channel inlet 43 and a flow channel outlet 44 connected to the outside.

[0058] The coolant flows in through the flow channel inlet 43 of the cooling plate 4 , flows along the S-shaped flow channel 42 and fully contacts the heat dissipation fins 2 , takes away the heat and flows out from the flow channel outlet 44 .

[0059] The coolant flow rate and the coolant flow channel in the cooling plate 4 can be changed according to the charging and discharging operation of the square battery 1 to achieve the best use effect.

[0060] Among them, ensure that the surfaces of the square battery 1 and the heat sink fins 2 are clean and free of dust, oil and other impurities, and then the planes are bonded together in a sandwich structure, and a suitable thermal conductive material is used to fill the gap between the square battery 1 and the heat sink fins 2, so as to reduce thermal resistance and improve heat dissipation effect.

[0061] The melting point of the low melting point alloy 6 is lower than the maximum rated temperature of the battery pack, which can be 80-120 degrees Celsius. The number and shape and size of the low melting point alloy 6 can be adjusted according to the temperature rise during the operation of the battery pack. The low melting point alloy material can be selected from materials with a melting point of about 120 degrees Celsius, 100 degrees Celsius, or 80 degrees Celsius or lower to improve the sensitivity of preventing thermal runaway of the battery pack.

[0062] The heat dissipation fins 2 are welded to the plug-in through holes 51 and the plug-in slots 41 to prevent the coolant from flowing out and ensure the normal operation of the battery pack.

[0063] Example 2

[0064] like Figure 7 As shown, different from Example 1, the cooling isolation member is an independent cooling support plate 45, and a flow channel hole 46 is provided in the middle of the cooling support plate 45. Cooling liquid is distributed in the flow channel hole 46, and the heat dissipating fins 2 pass through the outer surface of the cooling support plate 45 and contact the cooling liquid in the flow channel hole 46.

[0065] The heat dissipation fins 2 are welded to the cooling support plate 45 to prevent the coolant from flowing out and ensure the normal operation of the battery pack.

[0066] Compared with the first embodiment, the space of the flow channel through hole 46 is significantly larger than that of the S-shaped flow channel 42, and the cooling method using the through-type flow channel through hole 46 has a more timely response speed and a better heat dissipation effect.

[0067] Example 3

[0068] like Figure 8-13As shown, in order to break the quantity limit of the above-mentioned battery packs, an assembly unit 10 is also included for establishing a connection between two battery packs. The assembly unit 10 includes a heat dissipation connection component, an isolation connection plate 9, and a cooling connection plate 8, wherein:

[0069] A heat dissipation connection assembly, used to connect two battery packs, comprising a heat-insulating connection material 31 and heat-dissipating connection fins 21 distributed on both sides of the heat-insulating connection material 31, wherein the heat-insulating connection material 31 has the same structure as the heat-insulating material 3, and the heat-dissipating connection fins 21 have the same structure as the heat-dissipating fins 2;

[0070] The isolation connection plate 9 is used to support and place the heat insulation connection material 31 and isolate the heat insulation connection material 31 from the cooling connection plate 8. The first plug-in grooves 91 adapted to the heat dissipation fins 2 are symmetrically arranged on both sides of the surface;

[0071] The surface of the cooling connection plate 8 is symmetrically provided with second plug-in grooves 81 that are compatible with the heat dissipation fins 2 on both sides, and a central flow channel 82 is provided in the middle of the surface of the cooling connection plate 8. Both ends of the central flow channel 82 are provided with an assembly inlet 83 and an assembly outlet 84 that are respectively connected to the second plug-in grooves 81. The outer ports of the assembly inlet 83 and the assembly outlet 84 are both provided with L-shaped cooling plugs 20, and the two cooling plugs 20 are respectively plugged and connected to the flow channel inlet 43 and the flow channel outlet 44.

[0072] The cooling connecting plate 8 is connected to the cooling plate 4 via a fastener 7, wherein:

[0073] The fastener 7 includes a fastening plate 71 and two limiting guide blocks 72 symmetrically arranged on the inner surface of the fastening plate 71, a fastening through hole 73 is arranged between the two limiting guide blocks 72, and a waist-shaped groove 74 is arranged on the outer side of the limiting guide block 72; a first fastening bolt 76 connected to the cooling connecting plate 8 is installed in the fastening through hole 73, and a second fastening bolt 77 connected to the cooling plate 4 is installed in the waist-shaped groove 74; the limiting guide block 72 includes a first guiding inclined surface 75 connected to the surface of the fastening plate 71, and an obtuse angle is formed between the first guiding inclined surface 75 and the surface of the fastening plate 71;

[0074] The first fastening screw holes 85 matching with the first fastening bolts 76 are symmetrically arranged at both ends of the cooling connecting plate 8;

[0075] Second fastening screw holes 48 matching with the second fastening bolts 77 are provided around the side of the cooling plate 4, and a limiting guide groove 47 matching with the limiting guide block 72 is provided between the second fastening screw hole 48 and the corner of the cooling plate 4. The inner wall of the limiting guide groove 47 is provided with a second guide inclined surface 49 in sliding contact with the first guide inclined surface 75.

[0076] During assembly, the first fastening bolt 76 is simply pre-tightened through the fastening through hole 73 and the first fastening screw hole 85. During this process, the limiting guide block 72 is inserted into the limiting guide groove 47, and then the second fastening bolt 77 is continuously tightened, so that the first guide slope 75 continuously slides along the second guide slope 49, and drives the cooling plate 4 to move toward the cooling connection plate 8 until the heat dissipation connection fin 21 is in close contact with the outermost square battery 1 of the battery pack, and the assembly is completed. At the same time, in order to ensure that the heat dissipation connection fin 21 is in close contact with the outermost square battery 1 of the battery pack, the surface of the outermost square battery 1 of the battery pack in Example 1 can be slightly beyond the edge of the cooling plate 4 and the isolation plate 5.

[0077] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0078] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A module structure for dissipating heat from a square battery pack and preventing the spread of thermal runaway, characterized in that: include: A plurality of square batteries (1) are arranged side by side to form a battery pack; A plurality of heat dissipation components are placed between two adjacent square batteries (1), comprising a heat insulation material (3) and heat dissipation fins (2) distributed on both sides of the heat insulation material (3), a plurality of low melting point alloys (6) are distributed in the heat insulation material (3), both ends of the low melting point alloy (6) are in contact with the heat dissipation fins (2), and the heat dissipation fins (2) are in contact with the square batteries (1); The cooling isolation member is used to support and place the battery pack and the heat dissipation component, and has cooling liquid distributed inside. The heat dissipation fins (2) pass through the outer surface of the cooling isolation member and are in contact with the cooling liquid.

2. A module structure for heat dissipation and thermal runaway prevention of a square battery pack according to claim 1, characterized in that: The cooling isolation member comprises a cooling plate (4) and an isolation plate (5), wherein: The isolation plate (5) is used to support and place the battery pack and the heat dissipation component, and to isolate the battery pack from the cooling plate (4). A plurality of plug-in hole groups corresponding to the heat dissipation component are distributed on the surface of the isolation plate (5), and the plug-in hole groups include two plug-in through holes (51) adapted to the heat dissipation fins (2); The surface of the cooling plate (4) is evenly distributed with plug-in grooves (41) corresponding to the plug-in through holes (51), the ends of the plug-in grooves (41) are connected to S-shaped flow channels (42), and the two ends of the S-shaped flow channel (42) are respectively provided with a flow channel inlet (43) and a flow channel outlet (44) connected to the outside.

3. A module structure for heat dissipation and thermal runaway prevention of a square battery pack according to claim 2, characterized in that: The gap between the heat dissipation fins (2) and the square battery (1) is filled with heat conductive material.

4. A module structure for heat dissipation and thermal runaway prevention of a square battery pack according to claim 2, characterized in that: The melting point of the low melting point alloy (6) is lower than the maximum rated temperature of the battery pack.

5. A module structure for heat dissipation and thermal runaway prevention of a square battery pack according to claim 4, characterized in that: The melting point of the low melting point alloy (6) is 80-120 degrees Celsius.

6. A module structure for heat dissipation and thermal runaway prevention of a square battery pack according to claim 2, characterized in that: The heat dissipation fins (2) are connected to the plug-in through holes (51) and the plug-in slots (41) by welding.

7. A module structure for heat dissipation and thermal runaway prevention of a square battery pack according to claim 1, characterized in that: The cooling isolation member is an independent cooling support plate (45), a flow channel through hole (46) is provided in the middle of the cooling support plate (45), a cooling liquid is distributed in the flow channel through hole (46), and the heat dissipation fins (2) pass through the outer surface of the cooling support plate (45) and contact the cooling liquid in the flow channel through hole (46).

8. A module structure for dissipating heat and preventing the spread of thermal runaway in a square battery pack according to claim 7, characterized in that: The heat dissipation fins (2) are connected to the cooling support plate (45) by welding.

9. A module structure for heat dissipation and thermal runaway prevention of a square battery pack according to claim 2, characterized in that: It also includes an assembly unit (10) for establishing a connection between two battery packs, the assembly unit (10) including a heat dissipation connection component, an isolation connection plate (9), and a cooling connection plate (8), wherein: A heat dissipation connection assembly, used for connecting two battery packs, comprising a heat-insulating connection material (31) and heat-dissipating connection fins (21) distributed on both sides of the heat-insulating connection material (31), wherein the heat-insulating connection material (31) has the same structure as the heat-insulating material (3), and the heat-dissipating connection fins (21) have the same structure as the heat-dissipating fins (2); The isolation connection plate (9) is used to support and place the heat-insulating connection material (31) and to isolate the heat-insulating connection material (31) from the cooling connection plate (8), and first plug-in grooves (91) adapted to the heat dissipation fins (2) are symmetrically provided on both sides of the surface; Second plug-in grooves (81) adapted to the heat dissipation fins (2) are symmetrically provided on both sides of the surface of the cooling connection plate (8), a central flow channel (82) is provided in the middle of the surface of the cooling connection plate (8), and an assembly inlet (83) and an assembly outlet (84) respectively connected to the second plug-in grooves (81) are provided at both ends of the central flow channel (82), and L-shaped cooling plugs (20) are provided at the outer ports of the assembly inlet (83) and the assembly outlet (84), and the two cooling plugs (20) are respectively plug-connected to the flow channel inlet (43) and the flow channel outlet (44).

10. A module structure for heat dissipation and thermal runaway prevention of a square battery pack according to claim 9, characterized in that: The cooling connecting plate (8) is connected to the cooling plate (4) via a fastener (7), wherein: The fastener (7) comprises a fastening plate (71) and two limiting guide blocks (72) symmetrically arranged on the inner surface of the fastening plate (71); a fastening through hole (73) is arranged between the two limiting guide blocks (72); a waist-shaped groove (74) is arranged on the outer side of the limiting guide block (72); a first fastening bolt (76) connected to the cooling connecting plate (8) is installed in the fastening through hole (73); a second fastening bolt (77) connected to the cooling plate (4) is installed in the waist-shaped groove (74); the limiting guide block (72) comprises a first guiding inclined surface (75) connected to the surface of the fastening plate (71); an obtuse angle is formed between the first guiding inclined surface (75) and the surface of the fastening plate (71); First fastening screw holes (85) matching with the first fastening bolts (76) are symmetrically arranged at both ends of the cooling connection plate (8); Second fastening screw holes (48) matching with the second fastening bolts (77) are provided around the side of the cooling plate (4), a limiting guide groove (47) matching with the limiting guide block (72) is provided between the second fastening screw hole (48) and the corner of the cooling plate (4), and the inner wall of the limiting guide groove (47) is provided with a second guiding inclined surface (49) in sliding contact with the first guiding inclined surface (75).

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