Direct-cooling immersion battery box and battery pack

Abstract

The utility model provides a direct-cooling immersion battery box and a battery pack. The direct-cooling immersion battery box comprises a box body, an upper cover, a direct-cooling plate, a liquid inlet pipeline and a liquid outlet pipeline, a plurality of battery modules are placed in the box body, the box body is filled with immersion liquid, and the immersion liquid is made of an insulating material; the upper cover is detachably connected with the box body; the plurality of direct cooling plates are vertically arranged in the box body at intervals, one direct cooling plate is arranged on each of the two sides of the battery module in the width direction, and a circulating flow channel is arranged in each direct cooling plate; the liquid inlet pipeline is connected with inlets of the multiple direct cooling plates, and the liquid outlet pipeline is connected with outlets of the multiple direct cooling plates and used for introducing refrigerants into the circulating flow channel in a circulating mode. The refrigerant cools the immersion liquid, the immersion liquid cools the battery cell, the immersion liquid is in a standing state, the phenomenon that pressure is generated on the box body due to flowing of the immersion liquid is avoided, a circulating flow channel of the refrigerant is located on the direct cooling plate, and compared with the scheme that an immersion liquid flow channel is arranged on the side wall of the box body in the prior art, the pressure bearing capacity of the box body is greatly improved.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a direct-cooling immersion battery box and battery pack. Background Technology

[0002] With the large-scale commercialization of 20-foot standard containerized energy storage units, controlling the overall cell temperature difference within the battery pack has become crucial, as temperature differences significantly impact cell lifespan. Currently, most energy storage battery packs on the market are bottom-cooled, which suffers from small cooling area, low heat exchange efficiency, and an inability to effectively prevent thermal runaway. In response, immersion cooling has been proposed, which can effectively increase the heat exchange area and improve heat exchange efficiency, while also effectively preventing thermal runaway.

[0003] Most existing immersion cooling solutions rely on the fluid flow of the immersion liquid, with the tank itself serving as the flow channel. This results in poor pressure resistance and easy deformation of the tank. Currently, the pressure that a tank with its own flow channel can withstand is less than 1 bar, while the working pressure of a conventional liquid cooling unit is around 1 bar, leaving very little design margin. Utility Model Content

[0004] In view of this, the present invention proposes a direct-cooling immersion battery box and battery pack to solve the technical problems of the immersion liquid flow cooling scheme proposed in the background art, which uses the box body itself as the flow channel, resulting in poor pressure resistance and easy deformation of the box body.

[0005] The technical solution of this utility model is implemented as follows:

[0006] In a first aspect, this utility model provides a direct-cooling immersion battery box, including a box body, a top cover, a direct cooling plate, an inlet pipe, and an outlet pipe, wherein:

[0007] The box contains multiple battery modules and is filled with an immersion liquid, which is an insulating material.

[0008] The top cover is detachably connected to the box body;

[0009] Multiple direct cooling plates are vertically arranged at intervals in the housing, and one direct cooling plate is provided on each side of the battery module width direction. The direct cooling plate is provided with a circulation channel, and the two ends of the circulation channel are respectively provided with an inlet and an outlet, with the inlet being lower than the outlet.

[0010] The liquid inlet pipe is connected to the inlet of a plurality of direct cooling plates, and the liquid outlet pipe is connected to the outlet of a plurality of direct cooling plates, for circulating refrigerant into the circulation channel.

[0011] Based on the above technical solutions, preferably, the straight cooling plate includes a flat tube, two fins and two connectors. The circulation channel is formed inside the flat tube, and the two ends of the flat tube are the inlet and the outlet. The two fins are disposed on both sides of the flat tube and connected to the flat surface of the flat tube. The two connectors are respectively welded to the outlet and the inlet, and are respectively detachably connected to the liquid inlet pipe and the liquid outlet pipe.

[0012] Based on the above technical solutions, preferably, the flat tube includes multiple straight tubes, a first connecting tube, and a second connecting tube; the multiple straight tubes are arranged horizontally and parallel to each other, with one end of the lowest straight tube being the inlet and one end of the straight tube adjacent to the lowest straight tube being the outlet; the first connecting tube and the second connecting tube are U-shaped, with the first connecting tube connecting the uppermost straight tube and the lowermost straight tube, and the second connecting tube connecting the adjacent straight tubes, forming a structure connected end to end.

[0013] Based on the above technical solutions, preferably, the fin is a flat plate, and the fin is provided with multiple protrusions.

[0014] Based on the above technical solutions, preferably, a plurality of the protrusions are arranged in an array on the fin along the horizontal and vertical directions.

[0015] Based on the above technical solutions, preferably, the protrusion has hollowed-out grooves on both sides.

[0016] Based on the above technical solutions, preferably, the liquid inlet pipe includes a first main pipe and a first branch pipe. One end of the first main pipe extends out of the box body, and the other end is perpendicularly connected to the first branch pipe. The first branch pipe is provided with a plurality of first connectors, and the first connectors are connected to the inlet one by one.

[0017] Based on the above technical solutions, preferably, the liquid outlet pipeline includes a second main pipe and a second branch pipe. One end of the second main pipe extends out of the box body, and the other end is perpendicularly connected to the second branch pipe. The second branch pipe is provided with a plurality of second connectors, and the second connectors are connected to the outlets one by one.

[0018] Secondly, this utility model provides a battery pack, including a battery module and the direct-cooled immersion battery box described in the first aspect, wherein the battery module is installed in the box.

[0019] Based on the above technical solutions, preferably, the battery module includes multiple battery cells and spacers, with spacers provided between two adjacent battery cells. The spacers are located at the upper and lower ends of the side of the battery cells, and the length of the spacers is less than the length of the battery cells.

[0020] The direct-cooling immersion battery box and battery pack of this invention have the following advantages over the prior art:

[0021] (1) The box is filled with an immersion liquid, which is an insulating material. Multiple straight cooling plates are arranged vertically at intervals in the box, and one straight cooling plate is provided on each side of the battery module width direction. The straight cooling plate is provided with a circulation channel. The liquid inlet pipe and the liquid outlet pipe circulate refrigerant into the circulation channel. The refrigerant cools the immersion liquid, and the immersion liquid cools the battery cell. The immersion liquid is in a static state and will not exert pressure on the box due to the flow of the immersion liquid. Moreover, the circulation channel of the refrigerant is located on the straight cooling plate. Compared with the prior art, which sets the immersion liquid channel on the side wall of the box, the pressure bearing capacity of the box is greatly improved.

[0022] (2) The circulating flow channel is formed inside the flat tube, and two fins are arranged on both sides of the flat tube and connected to the flat surface of the flat tube, which can increase the heat exchange area of ​​the straight cooling plate and improve the heat exchange efficiency.

[0023] (3) Multiple straight pipes are horizontally arranged and parallel to each other. One end of the bottom straight pipe is the inlet, and one end of the straight pipe adjacent to the bottom straight pipe is the outlet. The first connecting pipe connects the top straight pipe and the bottom straight pipe, and the second connecting pipe connects the adjacent straight pipes to form a structure that is connected end to end. The above structure can improve the temperature uniformity of the straight cooling plate.

[0024] (4) By providing multiple protrusions on the fins, the heat exchange area of ​​the direct cooling plate can be further increased, thereby increasing the heat exchange probability;

[0025] (5) A spacer is provided between two adjacent cells of the battery module. The spacer is located at the upper and lower ends of the side of the cell, and the length of the spacer is less than the length of the cell. This creates a gap between the cells, allowing the immersion liquid to flow into the gap, thereby maximizing the contact area between the immersion liquid and the cell and improving the heat exchange efficiency. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a perspective view of the direct-cooling immersion battery box of this utility model;

[0028] Figure 2 This is an exploded view of the direct-cooling immersion battery box of this utility model;

[0029] Figure 3 This is a schematic diagram of the structure of the direct cooling plate of this utility model;

[0030] Figure 4 This is an exploded view of the direct cooling plate of this utility model;

[0031] Figure 5 This is a cross-sectional view of the fins of this utility model;

[0032] Figure 6 This is a cross-sectional view of the flat tube of this utility model;

[0033] Figure 7 This is a schematic diagram of the liquid inlet pipe of this utility model;

[0034] Figure 8 This is a schematic diagram of the liquid outlet pipe of this utility model;

[0035] Figure 9 This is a schematic diagram of the battery pack structure of this utility model;

[0036] Figure 10 This is an exploded view of the battery module of this utility model.

[0037] Explanation of reference numerals in the attached diagram: 1-box body, 2-top cover, 3-direct cooling plate, 4-liquid inlet pipe, 5-liquid outlet pipe, 6-sealing strip;

[0038] 100-Battery module, 101-Battery cell, 102-Separator; 200-Circulation channel, 201-Inlet, 202-Outlet;

[0039] 31-Flat tube, 311-Straight tube, 312-First connecting tube, 313-Second connecting tube, 32-Fin, 321-Protrusion, 322-Hollowed groove, 33-Joint;

[0040] 41-First main pipe, 42-First branch pipe, 421-First connector;

[0041] 51-Second main pipe, 52-Second branch pipe, 521-Second connector. Detailed Implementation

[0042] The technical solutions of this utility model will be clearly and completely described below with reference to the embodiments of this utility model. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0043] Reference Figures 1-10As shown, in a first aspect embodiment of the present invention, a direct-cooling immersion battery box is provided, comprising a box body 1, a top cover 2, a direct cooling plate 3, an inlet pipe 4, and an outlet pipe 5, wherein:

[0044] The housing 1 contains multiple battery modules 100 and is filled with an immersion liquid, which is an insulating material; the immersion liquid can be a hydrocarbon or a fluorinated liquid.

[0045] The upper cover 2 is detachably connected to the box body 1 and is sealed by the sealing strip 6 to achieve internal sealing of the battery box and prevent the immersion liquid from overflowing.

[0046] Multiple direct cooling plates 3 are vertically arranged at intervals in the housing 1, and one direct cooling plate 3 is provided on each side of the battery module 100 in the width direction. A battery module 100 is provided between two adjacent direct cooling plates 3. A circulation channel 200 is provided in the direct cooling plate 3. An inlet 201 and an outlet 202 are provided at both ends of the circulation channel 200, and the inlet 201 is lower than the outlet 202.

[0047] The liquid inlet pipe 4 is connected to the inlets 201 of multiple direct cooling plates 3, and the liquid outlet pipe 5 is connected to the outlets 202 of multiple direct cooling plates 3, for circulating refrigerant into the circulation channel 200. The refrigerant can be R134a or R1234YF. R134a (1,1,1,2-tetrafluoroethane), also known as R-134a, with the chemical formula CH2FCF3, is a chlorine-free refrigerant that does not damage the ozone layer and has good safety properties (non-flammable, non-explosive, non-toxic, non-irritating, and non-corrosive). Its cooling capacity and efficiency are very close to R-12 (dichlorodifluoromethane, Freon), so it is considered an excellent long-term alternative refrigerant. R1234YF, also known as tetrafluoropropylene, is a fourth-generation environmentally friendly refrigerant. As a single working fluid, it has excellent environmental parameters, lower lifespan climate performance than R134a, and the same atmospheric decomposition products as R134a.

[0048] In this embodiment, the direct-cooled immersion battery box cools the immersion liquid with refrigerant, and the immersion liquid cools the battery cell 101. The immersion liquid is in a static state and will not exert pressure on the box body 1 due to the flow of the immersion liquid. Moreover, the circulation channel 200 of the refrigerant is located on the direct cooling plate 3. Compared with the prior art, which sets the immersion liquid channel on the side wall of the box body 1, the pressure bearing capacity of the box body 1 is greatly improved.

[0049] In some embodiments, the direct cooling plate includes a flat tube 31, two fins 32 and two connectors 33. The circulating flow channel 200 is formed inside the flat tube 31. The two ends of the flat tube 31 are the inlet 201 and the outlet 202. The two fins 32 are arranged on both sides of the flat tube 31 and connected to the flat surface of the flat tube 31. The two connectors 33 are respectively welded to the outlet 202 and the inlet 201, and are respectively detachably connected to the liquid inlet pipe 4 and the liquid outlet pipe 5. By forming the circulating flow channel 200 inside the flat tube 31 and arranging the two fins 32 on both sides of the flat tube 31 and connecting them to the flat surface of the flat tube 31, the heat exchange area of the direct cooling plate 3 can be increased and the heat exchange efficiency can be improved. The connector 33 and the liquid inlet pipe 4 are connected by screws, and the connector 33 and the liquid outlet pipe 5 are connected by screws to achieve detachable connection. By replacing the connectors 33 with different inner diameters, the flow distribution of each intermediate cooling plate in the battery pack system can be adjusted to improve the temperature uniformity. The material of the direct cooling plate is aluminum and the connection process is brazing.

[0050] In some embodiments, the flat tube 31 includes a plurality of straight tubes 311, a first connecting tube 312 and a second connecting tube 313. The plurality of straight tubes 311 are horizontally arranged and parallel to each other. One end of the lowermost straight tube 311 is the inlet 201, and one end of the straight tube 311 adjacent to the lowermost straight tube 311 is the outlet 202. The first connecting tube 312 and the second connecting tube 313 are U-shaped. The first connecting tube 312 connects the uppermost straight tube 311 and the lowermost straight tube 311, and the second connecting tube 313 connects the adjacent straight tubes 311 to form a structure connected end to end. The circulating flow channel 200 is from bottom to top. Since the temperature is affected by pressure, the temperature on the inlet 201 side of the direct cooling plate 3 is higher than that on the outlet 202 side. Due to the pressure loss, the temperature of the refrigerant in the red arrow flow path is higher than that of the green refrigerant. The red arrow flow path is adjacent to the green arrow flow path, which can improve the temperature uniformity effect of the direct cooling plate 3.

[0051] In some embodiments, the fin 32 is a flat plate, and a plurality of bumps 321 are provided on the fin 32. By providing a plurality of bumps 321 on the fin 32, the heat exchange area of the direct cooling plate 3 can be further increased, thereby increasing the heat exchange probability. The bumps 321 can be obtained by stamping on the flat plate, and the shape of the bumps 321 is a "U" shape.

[0052] In some embodiments, the plurality of bumps 321 are arranged in an array in the horizontal and vertical directions on the fin 32. Through the above settings, the heat exchange of the entire fin 32 becomes more uniform, improving the temperature uniformity effect of the fin 32.

[0053] In some embodiments, the protrusion 321 is provided with perforated grooves 322 on both sides. The perforated grooves 322 allow the immersion liquid to pass through them, enabling rapid heat exchange between the immersion liquid and the inner surface of the protrusion 321, thereby improving heat exchange efficiency.

[0054] In some embodiments, the liquid inlet pipe 4 includes a first main pipe 41 and a first branch pipe 42. One end of the first main pipe 41 extends out of the housing 1, and the other end is perpendicularly connected to the first branch pipe 42. The first branch pipe 42 is provided with a plurality of first connectors 421, and the first connectors 421 are connected to the inlet 201 one by one. The position where the first main pipe 41 extends out of the housing 1 is sealed to prevent leakage of the immersion liquid. The first connectors 421 are connected to the connectors 33 by screws to connect the pipelines. Disassembly does not require disassembling and removing the direct cooling plate 3, which facilitates the installation and disassembly of the direct cooling plate 3 and improves the convenience of installation and maintenance.

[0055] In some embodiments, the liquid outlet pipe 5 includes a second main pipe 51 and a second branch pipe 52. One end of the second main pipe 51 extends out of the housing 1, and the other end is perpendicularly connected to the second branch pipe 52. The second branch pipe 52 is provided with a plurality of second connectors 521, and the second connectors 521 are connected to the outlets 202 one by one. The position where the second main pipe 51 extends out of the housing 1 is sealed to prevent leakage of the immersion liquid. The second connectors 521 are connected to the connectors 33 by screws to connect the pipelines. Disassembly does not require disassembling and removing the direct cooling plate 3, which facilitates the installation and disassembly of the direct cooling plate 3 and improves the convenience of installation and maintenance.

[0056] The working principle of the direct-cooled immersion battery box is as follows: The direct-cooling plate 3 is provided with a circulation channel 200. The liquid inlet pipe 4 and the liquid outlet pipe 5 circulate refrigerant into the circulation channel 200. The direct-cooling plate 3 is provided on both sides of the battery module 100 in the width direction. The refrigerant in the direct-cooling plate 3 cools the immersion liquid, and the immersion liquid cools the battery cell 101. The immersion liquid is in a static state and will not exert pressure on the box body 1 due to the flow of the immersion liquid. Moreover, the circulation channel 200 of the refrigerant is located on the direct-cooling plate 3. Compared with the existing technology where the immersion liquid channel is located on the side wall of the box body 1, the pressure bearing capacity of the box body 1 is greatly improved.

[0057] Based on the same concept, a second aspect of this utility model proposes a battery pack, including a battery module 100 and the direct-cooled immersion battery box described in the first aspect embodiment, wherein the battery module 100 is installed in the box 1.

[0058] In some embodiments, the battery module 100 includes a plurality of battery cells 101 and spacers 102. A spacer 102 is provided between two adjacent battery cells 101. The spacer 102 is located at the upper and lower ends of the side of the battery cell 101, and the length of the spacer 102 is less than the length of the battery cell 101. The spacer 102 creates gaps between the battery cells 101, allowing the immersion liquid to flow into these gaps, maximizing the contact area between the immersion liquid and the battery cells 101, and improving heat exchange efficiency. The spacer 102 can be made of PC material, which is colorless and transparent, heat-resistant, impact-resistant, flame-retardant (BI grade), and has good mechanical properties within normal operating temperatures.

[0059] This utility model has the following advantages:

[0060] (1) The cooling area was increased, which improved the cooling efficiency;

[0061] (2) The design of the circulation channel 200 can improve the temperature uniformity of the fins 32 and reduce the temperature difference of the immersion liquid;

[0062] (3) The immersion liquid is in a static state and will not exert pressure on the box 1 due to the flow of the immersion liquid. Moreover, the refrigerant circulation channel 200 is located on the direct cooling plate 3. Compared with the prior art, which sets the immersion liquid channel on the side wall of the box 1, the pressure bearing capacity of the box 1 is greatly improved and the box 1 will not be deformed due to the pressure.

[0063] (4) The thermal runaway problem has been solved;

[0064] (5) Compared with traditional immersion cooling, it reduces the number of plate heat exchangers and water pumps, improves heat exchange efficiency, and reduces the number of parts, thus reducing costs.

[0065] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A direct-cooling immersion battery box, characterized in that, It includes a housing (1), a top cover (2), a direct cooling plate (3), an inlet pipe (4), and an outlet pipe (5), wherein: The housing (1) contains multiple battery modules (100), and the housing (1) is filled with an immersion liquid, which is an insulating material. The top cover (2) is detachably connected to the box body (1); Multiple direct cooling plates (3) are vertically arranged at intervals in the housing (1), and one direct cooling plate (3) is provided on each side of the battery module (100) in the width direction. A circulation channel (200) is provided in the direct cooling plate (3), and an inlet (201) and an outlet (202) are provided at both ends of the circulation channel (200). The inlet (201) is lower than the outlet (202). The liquid inlet pipe (4) is connected to the inlet (201) of a plurality of direct cooling plates (3), and the liquid outlet pipe (5) is connected to the outlet (202) of a plurality of direct cooling plates (3) for circulating refrigerant into the circulation channel (200).

2. The direct-cooling immersion battery box as described in claim 1, characterized in that, The direct cooling plate includes a flat tube (31), two fins (32) and two connectors (33). The flat tube (31) forms the circulation channel (200) inside. The two ends of the flat tube (31) are the inlet (201) and the outlet (202). The two fins (32) are disposed on both sides of the flat tube (31) and connected to the flat surface of the flat tube (31). The two connectors (33) are respectively welded to the outlet (202) and the inlet (201), and are respectively detachably connected to the liquid inlet pipe (4) and the liquid outlet pipe (5).

3. The direct-cooling immersion battery box as described in claim 2, characterized in that, The flat tube (31) includes multiple straight tubes (311), a first connecting tube (312), and a second connecting tube (313). The multiple straight tubes (311) are arranged horizontally and parallel to each other. One end of the lowest straight tube (311) is the inlet (201), and one end of the straight tube (311) adjacent to the lowest straight tube (311) is the outlet (202). The first connecting tube (312) and the second connecting tube (313) are U-shaped. The first connecting tube (312) connects the uppermost straight tube (311) and the lowermost straight tube (311), and the second connecting tube (313) connects the adjacent straight tubes (311), forming a structure that is connected end to end.

4. The direct-cooling immersion battery box as described in claim 3, characterized in that, The fin (32) is a flat plate, and the fin (32) is provided with a plurality of protrusions (321).

5. The direct-cooling immersion battery box as described in claim 4, characterized in that, Multiple protrusions (321) are arranged in an array on the fin (32) in the horizontal and vertical directions.

6. The direct-cooling immersion battery box as described in claim 5, characterized in that, The protrusion (321) has hollowed-out grooves (322) on both sides.

7. The direct-cooling immersion battery box as described in claim 1, characterized in that, The liquid inlet pipe (4) includes a first main pipe (41) and a first branch pipe (42). One end of the first main pipe (41) extends out of the box (1), and the other end is vertically connected to the first branch pipe (42). The first branch pipe (42) is provided with a plurality of first connectors (421), and the first connectors (421) are connected to the inlet (201) one by one.

8. The direct-cooling immersion battery box as described in claim 1, characterized in that, The liquid outlet pipe (5) includes a second main pipe (51) and a second branch pipe (52). One end of the second main pipe (51) extends out of the box body (1), and the other end is vertically connected to the second branch pipe (52). The second branch pipe (52) is provided with a plurality of second connectors (521), and the second connectors (521) are connected to the outlet (202) one by one.

9. A battery pack, characterized in that, It includes a battery module (100) and a direct-cooled immersion battery box as described in any one of claims 1-8, wherein the battery module (100) is installed in the box body (1).

10. The battery pack as claimed in claim 9, characterized in that, The battery module (100) includes multiple battery cells (101) and spacers (102). A spacer (102) is provided between two adjacent battery cells (101). The spacer (102) is located at the upper and lower ends of the side of the battery cell (101), and the length of the spacer (102) is less than the length of the battery cell (101).

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