Liquid cooling plate, battery pack and lower housing thereof, and energy storage system

Abstract

The present application discloses a liquid cooling plate, a battery pack and a lower housing thereof, and an energy storage system. A plurality of main liquid cooling flow channels and auxiliary liquid cooling flow channels are arranged in a liquid cooling plate of a battery pack lower housing, so that an integrated design of the liquid cooling plate and the battery pack lower housing is achieved, and thus an independent liquid cooling plate does not need to be mounted, increasing the space utilization rate of the battery pack, and thus increasing the energy density of the battery pack. Moreover, the auxiliary liquid cooling flow channels work in conjunction with the main liquid cooling flow channels, so that the heat exchange effect of a cooling liquid and battery cells can be improved, and the temperature uniformity of the battery cells is improved, mitigating the technical problem in the related art that the temperature uniformity of the battery cells is poor due to a significant difference between the water temperature of a water inlet and the water temperature of a water outlet of the liquid cooling plate.

Description

Liquid cooling plate, battery pack and its lower box, energy storage system

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on December 1, 2023, with application number 202323291926.4. The entire contents of the above application are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of battery technology, and in particular to a liquid cooling plate, a battery pack and its lower box, and an energy storage system. Background Art

[0003] The temperature environment within the battery pack significantly impacts the reliability, lifespan, and performance of the battery cells. Therefore, maintaining the temperature within the battery pack within a certain range is crucial. Liquid cooling technology is an effective method for maintaining this temperature within the battery pack. Liquid cooling uses liquid convection to remove heat from the cells, reducing their temperature.

[0004] In the prior art, independent liquid cooling plates are typically installed within the battery pack casing to cool the battery cells. These plates are mechanically fixed to the battery pack casing. The internal flow channels of these plates are often U-shaped. This results in poor temperature consistency in the battery cells due to the significant difference in water temperature between the inlet and outlet, which in turn reduces their service life. SUMMARY OF THE INVENTION

[0005] The present application provides a liquid cooling plate, a battery pack and its lower box, and an energy storage system to solve the above technical problems.

[0006] In the first aspect, an embodiment of the present application provides a liquid cooling plate, which includes a main liquid cooling channel and an auxiliary liquid cooling channel, wherein each of the main liquid cooling channel and the auxiliary liquid cooling channel has one end connected to the liquid inlet of the liquid cooling plate, and the other end of the auxiliary liquid cooling channel is connected to the middle part of the main liquid cooling channel.

[0007] In a second aspect, an embodiment of the present application provides a battery pack lower box, which includes a liquid cooling plate of one of the aforementioned embodiments, and a plurality of side plates surrounding the liquid cooling plate, wherein the plurality of side plates form a accommodating cavity around the liquid cooling plate.

[0008] In a third aspect, an embodiment of the present application further provides a battery pack, which includes the battery pack lower box of one of the aforementioned embodiments.

[0009] In a fourth aspect, an embodiment of the present application further provides an energy storage system, which includes the battery pack of the aforementioned embodiment. Beneficial effects

[0010] The beneficial effects of the present application are as follows: in the embodiment of the present application, by arranging multiple main liquid-cooling channels and auxiliary liquid-cooling channels in the liquid-cooling plate, one end of each of the main liquid-cooling channel and the auxiliary liquid-cooling channel is connected to the liquid inlet of the liquid-cooling plate, and the other end of the auxiliary liquid-cooling channel is connected to the middle part of the main liquid-cooling channel, so that the auxiliary liquid-cooling channel cooperates with the main liquid-cooling channel to improve the heat exchange effect between the coolant and the battery cell, and improve the temperature consistency of the battery cell, thereby improving the technical problem in the related art that the temperature consistency of the battery cell is poor due to the large difference between the water temperature at the water inlet and the water outlet of the liquid cooling plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG1 is a schematic diagram of the planar structure of the liquid cooling plate provided in this application.

[0012] FIG2 is a schematic diagram of the cross-sectional structure along the AA′ direction in FIG1 .

[0013] FIG3 is a schematic diagram of a three-dimensional structure of the lower box of the battery pack provided in this application.

[0014] FIG4 is a schematic diagram of the exploded structure of the lower box of the battery pack in FIG3 .

[0015] FIG5 is a bottom view of the lower box of the battery pack in FIG3 .

[0016] FIG6 is a schematic diagram of the structure of the lower box of the battery pack from above in FIG3 .

[0017] FIG7 is a schematic diagram showing the detailed structure of the water inlet and water outlet in FIG3 .

[0018] Reference numerals:

[0019] 100. Battery pack lower box; 101. Accommodation cavity;

[0020] 10. Liquid cooling plate; 11. Upper cavity wall; 12. Lower cavity wall; 13. Left cavity wall; 14. Right cavity wall; 15. Front cavity wall; 16. Rear cavity wall; 110. Cavity structure; 111. First partition; 112. Second partition; 113. Third partition; 114. Fourth partition; 115. Fifth partition; 151. Liquid inlet; 152. Liquid outlet; 161. Opening; 1131. Connecting portion; 1132. Extension portion;

[0021] 20. Side panel; 21. Left side panel; 22. Right side panel; 23. Front panel; 24. Rear panel; 231. First window; 232. Connector mounting plate; 241. Second window;

[0022] 30. Frame beam; 31. Left frame beam; 32. Right frame beam; 33. Front frame beam; 34. Rear frame beam; 311. Hoisting structure; 312. Mounting and fixing holes; 313. Through hole;

[0023] 40. Strengthening beams;

[0024] 51. Water inlet; 52. Water outlet; 53. Water inlet connection block; 54. Water outlet connection block; 511. First subsection; 512. Second subsection; 513. Corner section;

[0025] 60. Main liquid-cooling channel; 60-1. First type of main channel; 60-2. Second type of main channel; 61. Main channel; 70. Auxiliary liquid-cooling channel; 71. First auxiliary channel; 72. Second auxiliary channel; 601. Sub-channel. Modes for Carrying Out the Invention

[0026] In the description of this application, unless otherwise specified or limited, the terms "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and can refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0027] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0028] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meanings.

[0029] In response to the problem of poor temperature consistency of battery cells in battery packs in related technologies, the inventors of this application discovered in their research that this is mainly because the internal flow channels of the liquid cooling plates in the battery packs are mostly U-shaped structures. The water temperature at the water inlet and outlet of such liquid cooling plates differs greatly, resulting in poor temperature consistency of the battery cells. In addition, with the continuous development of the electrochemical energy storage industry, energy storage power stations have increasingly higher requirements for area energy density, resulting in the emergence of various new battery packs and battery energy storage systems on the market. For example, battery packs are getting larger and larger, but their cell temperature difference control is worse than that of small-sized battery packs.

[0030] To this end, the present application provides a liquid cooling plate, a battery pack and its lower box, and an energy storage system to solve the above problems, wherein the liquid cooling plate is used to dissipate heat from the battery cells in the battery pack.

[0031] Please refer to Figures 1 and 2. Figure 1 is a schematic diagram of the planar structure of the liquid cooling plate provided in this application, and Figure 2 is a schematic diagram of the cross-sectional structure along the A-A' direction in Figure 1. The liquid cooling plate 10 includes a main liquid cooling channel 60 and an auxiliary liquid cooling channel 70. The liquid cooling plate 10 is also provided with a liquid inlet 151 and a liquid outlet 152. The main liquid cooling channel 60 and the auxiliary liquid cooling channel 70 each have one end connected to the liquid inlet 151 of the liquid cooling plate 10, and the other end of the auxiliary liquid cooling channel 70 is connected to the middle portion of the main liquid cooling channel 60. Among them, the middle part of the main liquid-cooling channel 60 is 1 / 2 to 9 / 10 of the total length of the main liquid-cooling channel 60. For example, the middle part may be 1 / 2, 2 / 3, 3 / 4, 3 / 5, 4 / 5, 5 / 6, 4 / 7, 5 / 7, 6 / 7, 5 / 8, 7 / 8, 5 / 9, 6 / 9, 7 / 9, 8 / 9, 7 / 10, 9 / 10, etc. of the total length of the main liquid-cooling channel 60.

[0032] Specifically, the main liquid-cooling channel 60 includes a plurality of main channels 61 extending along a first direction X. The plurality of main channels 61 are spaced apart along a second direction Y, and adjacent main channels 61 are interconnected. The first direction X and the second direction Y are different. For example, the first direction X is the length of the liquid-cooling plate 10, and the second direction Y is the width of the liquid-cooling plate 10, where the length of the liquid-cooling plate 10 is greater than the width of the liquid-cooling plate 10. The auxiliary liquid-cooling channel 70 is located around the main liquid-cooling channel 60 and includes a first auxiliary channel 71 and a second auxiliary channel 72 that are interconnected. The first auxiliary channel 71 extends along the first direction X, and the second auxiliary channel 72 extends along the second direction Y.

[0033] The main liquid cooling channel 60 also includes a first-class main channel 60-1 and a second-class main channel 60-2 arranged adjacent to each other, and the second-class main channel 60-2 is located on the side of the first-class main channel 60-1 away from the first auxiliary channel 71. The first-class main channel 60-1 and the second-class main channel 60-2 both include multiple main channels 61. The liquid inlet end of the first-class main channel 60-1 is connected to the liquid inlet 151, the liquid outlet end of the first-class main channel 60-1 is connected to the liquid inlet end of the second-class main channel 60-2, the liquid outlet end of the second-class main channel 60-2 is connected to the liquid outlet 152, the liquid inlet end of the first auxiliary channel 71 is connected to the liquid inlet 151, the liquid outlet end of the first auxiliary channel 71 is connected to the liquid inlet end of the second auxiliary channel 72, and the liquid outlet end of the second auxiliary channel 72 is connected to one end of the second-class main channel 60-2 away from the liquid outlet 152. Among them, the liquid inlet 151 refers to the channel for the coolant to enter the liquid cooling plate 10, and the liquid outlet 152 refers to the channel for the coolant to flow out of the liquid cooling plate 10, and the liquid inlet end and liquid outlet end of the main channel 61 and the auxiliary channel are similar to the liquid inlet 151 and the liquid outlet 152, respectively, and are channels for the coolant to flow in and out, respectively.

[0034] In this embodiment, by connecting the liquid outlet end of the second auxiliary flow channel 72 with the end of the second type main channel 60-2 away from the liquid outlet 152, the coolant in the auxiliary liquid cooling flow channel 70 can be heat exchanged with the coolant in the main liquid cooling flow channel 60, thereby improving the heat exchange effect between the coolant and the battery cell, and further improving the temperature consistency of the battery cell, alleviating the technical problem in the related art that the temperature consistency of the battery cell is poor due to the large difference between the water temperature at the water inlet and the water outlet of the liquid cooling plate 10.

[0035] Specifically, the liquid cooling plate 10 has a cavity structure 110, and the main liquid cooling channel 60 and the auxiliary liquid cooling channel 70 are formed in the cavity structure 110. The liquid cooling plate 10 includes an upper cavity wall 11 and a lower cavity wall 12 disposed oppositely, and a plurality of side cavity walls connected between the upper cavity wall 11 and the lower cavity wall 12. The plurality of side cavity walls are connected end to end and surround the upper cavity wall 11 and the lower cavity wall 12 to form the cavity structure 110. The plurality of side cavity walls include a left cavity wall 13 and a right cavity wall 14 disposed oppositely, and a front cavity wall 15 and a rear cavity wall 16 connected between the left cavity wall 13 and the right cavity wall 14. The liquid inlet 151 and the liquid outlet 152 are both located on the front cavity wall 15, that is, the liquid inlet 151 and the liquid outlet 152 are located on the same side of the liquid cooling plate 10. In other words, the front cavity wall 15 is provided with an opening, while the other cavity walls are not provided with openings, so as to seal the liquid cooling flow channel. Optionally, the side cavity walls are friction stir welded with the upper cavity wall 11 and / or the lower cavity wall 12 to improve the reliability of the flow channel sealing.

[0036] The liquid cooling plate 10 further includes a first partition 111, a second partition 112, and a third partition 113 arranged in the cavity structure 110. The first partition 111 extends along the first direction X and is located between the first-type main channel 60-1 and the second-type main channel 60-2; the second partition 112 extends along the first direction X and is located between the first-type main channel 60-1 and the first auxiliary channel 71; the third partition 113 extends along the second direction Y and is located on a side of the first-type main channel 60-1 away from the liquid inlet 151. The third partition 113 includes a connecting portion 1131, which is connected between the first partition 111 and the second partition 112.

[0037] The third partition 113 also includes an extension portion 1132, which extends along the second direction Y from the end of the connecting portion 1131 away from the second partition 112. The extension portion 1132 is located on a side of the second-type main channel 60-2 away from the liquid outlet 152, and is provided with a plurality of openings 161. The second auxiliary channel 72 communicates with the end of the second-type main channel 60-2 away from the liquid outlet 152 through the openings 161. The plurality of openings 161 are evenly arranged on the extension portion 1132, i.e., the distance between two adjacent openings 161 is equal, so that the heat exchange between the coolant in the auxiliary liquid-cooling channel 70 and the coolant in the main liquid-cooling channel 60 is more uniform, thereby better improving the heat exchange effect between the coolant and the battery cells, and further improving the temperature consistency of the battery cells.

[0038] The first baffle 111, the second baffle 112, and the third baffle 113 are all connected between the upper chamber wall 11 and the lower chamber wall 12. The second baffle 112 is located between the first baffle 111 and the left chamber wall 13. The third baffle 113 is located at the end of the first baffle 111 away from the front chamber wall 15 and is connected to the first baffle 111. The first auxiliary flow channel 71 is formed between the second baffle 112 and the left chamber wall 13, and the second auxiliary flow channel 72 is formed between the third baffle 113 and the rear chamber wall 16. The first-class main flow channel 60-1 is formed between the first baffle 111 and the second baffle 112, and the second-class main flow channel 60-2 is formed between the first baffle 111 and the right chamber wall 14. One end of the first partition 111 is connected to the third partition 113, and a gap is formed between the other end and the front cavity wall 15. The liquid outlet of the first type main channel 60-1 is connected to the liquid inlet of the second type main channel 60-2 through the gap.

[0039] The liquid cooling plate 10 also includes a plurality of fourth baffles 114 extending along the first direction X and located between adjacent main channels 61. The fourth baffles 114 are connected between the upper chamber wall 11 and the lower chamber wall 12. The fourth baffles 114 within the first-type main channel 60-1 are located between the first baffle 111 and the second baffle 112. Specifically, the first baffle 111 and the fourth baffle 114, as well as the fourth baffle 114 and the second baffle 112, form the main channel 61 within the first-type main channel 60-1. The fourth baffles 114 within the second-type main channel 60-2 are located between the first baffle 111 and the right chamber wall 14. Specifically, the first baffle 111 and the fourth baffle 114, as well as the fourth baffle 114 and the right chamber wall 14, form the main channel 61 within the second-type main channel 60-2. The second partition plate 112 is located between the fourth partition plate 114 and the left cavity wall 13 , and the third partition plate 113 is located between the fourth partition plate 114 and the rear cavity wall 16 .

[0040] M fourth baffles 114 are provided in the first-type main channel 60-1, and N fourth baffles 114 are provided in the second-type main channel 60-2, where both M and N are odd numbers greater than or equal to 1. As shown in Figures 1 and 2, one fourth baffle 114 is provided in the first-type main channel 60-1 and one fourth baffle 114 is provided in the second-type main channel 60-2. In one embodiment, the first baffle 111 is located in the central region of the liquid cooling plate 10. In this case, the number of fourth baffles 114 in the first-type main channel 60-1 can be equal to the number of fourth baffles 114 in the second-type main channel 60-2, that is, M = N. When the first baffle 111 is located in the central region of the liquid cooling plate 10, the width of the first baffle 111 in the second direction Y is greater than the width of the fourth baffle 114 in the second direction Y, thereby reinforcing the structure of the liquid cooling plate 10 and improving its load-bearing capacity.

[0041] Among the M fourth partitions 114, one end of the Pth fourth partition 114 is connected to the front cavity wall 15, and a gap is formed between the other end and the third partition 113; the fourth partition 114 adjacent to the Pth fourth partition 114 has a gap between one end and the front cavity wall 15, and the other end is connected to the third partition 113; wherein P is an odd number greater than or equal to 1, and P ≤ M. Among the N fourth partitions 114, one end of the Qth fourth partition 114 is connected to the front cavity wall 15, and a gap is formed between the other end and the third partition 113; the fourth partition 114 adjacent to the Qth fourth partition 114 has a gap between one end and the front cavity wall 15, and the other end is connected to the third partition 113; wherein Q is an odd number greater than or equal to 1, and Q ≤ N. As shown schematically in Figures 1 and 2, a fourth partition 114 is provided in each of the first-type main channel 60-1 and the second main channel 61. At this time, M=N=P=Q. Taking the first-type main channel 60-1 as an example, the fourth partition 114 in the first-type main channel 60-1 divides the first-type main channel 60-1 into two main channels 61. One end of the fourth partition 114 is connected to the front cavity wall 15, and there is a gap between the other end and the third partition 113. The two main channels 61 in the first main channel 61 are connected through the gap.

[0042] In this way, the fourth partition 114 cooperates with the first partition 111 to divide the main liquid-cooling channel 60 in the cavity structure 110 into multiple main channels 61. The coolant enters the main liquid-cooling channel 60 through the liquid inlet 151, and after passing through the multiple main channels 61 in the main liquid-cooling channel 60 in sequence, it flows out from the liquid outlet 152. The flow path of the coolant in the main liquid-cooling channel 60 is S-shaped, that is, the flow path of the main liquid-cooling channel 60 is S-shaped. As shown in Figure 1, the flow direction of the coolant is schematically shown. In Figure 1, the flow path of the coolant is represented by a straight line with an arrow. The direction of the arrow is the flow direction of the coolant in the main liquid-cooling channel 60. The straight line with two arrows is used to indicate the position of each type of channel. In this way, by setting the flow path of the main liquid-cooling channel 60 to be S-shaped, compared with the conventional U-shaped channel, the heat exchange effect between the coolant and the battery cell can be further improved, and the temperature consistency of the battery cell can be improved.

[0043] The liquid cooling plate 10 also includes a plurality of fifth baffles 115 disposed within each of the main channels 61, the fifth baffles 115 being connected between the upper cavity wall 11 and the lower cavity wall 12. The plurality of fifth baffles 115 extend along the first direction X and are spaced apart along the second direction Y. A gap exists between one end of each fifth baffle 115 and the front cavity wall 15, and a gap exists between the other end and the rear cavity wall 16. The plurality of fifth baffles 115 divide each of the main channels 61 into a plurality of sub-channels 601 to further improve the heat exchange effect between the coolant and the battery cells, thereby further improving the temperature consistency of the battery cells. Moreover, the provision of a plurality of fifth baffles 115 can further improve the structural strength of the liquid cooling plate 10 and increase the load-bearing capacity of the liquid cooling plate 10. Optionally, the plurality of sub-channels 601 are evenly arranged, and the channel widths of two adjacent sub-channels 601 in the second direction Y are the same.

[0044] In this embodiment, the main liquid-cooling channel 60 and the auxiliary liquid-cooling channel 70 are arranged in the cavity structure 110 of the liquid-cooling plate 10, and the auxiliary liquid-cooling channel 70 is located around the main liquid-cooling channel 60, and the liquid outlet end of the auxiliary liquid-cooling channel 70 is connected with the end of the second type of main channel 60-2 of the main liquid-cooling channel 60 away from the liquid outlet 152, so that the auxiliary liquid-cooling channel 70 can be located at the edge of the liquid-cooling plate 10, and the number of battery cells passed through is small, and the total length of the auxiliary liquid-cooling channel 70 is smaller than the total length of the main liquid-cooling channel 60, so that the temperature of the coolant in the auxiliary liquid-cooling channel 70 is lower than the temperature of the coolant in the main liquid-cooling channel 60. In this way, the coolant in the auxiliary liquid-cooling channel 70 exchanges heat with the coolant in the main liquid-cooling channel 60 at the opening 161 of the third partition 113, thereby improving the heat exchange effect between the coolant and the battery cell, and further improving the temperature consistency of the battery cell, alleviating the technical problem in the related art that the temperature consistency of the battery cell is poor due to the large difference between the water temperature at the water inlet and the water outlet of the liquid cooling plate 10.

[0045] In one embodiment, the present application also provides a battery pack lower case. Please refer to Figures 1 to 7. Figure 3 is a schematic diagram of a three-dimensional structure of the battery pack lower case provided by the present application, Figure 4 is a schematic diagram of the exploded structure of the battery pack lower case in Figure 3, Figure 5 is a schematic diagram of a bottom-view structure of the battery pack lower case in Figure 3, Figure 6 is a schematic diagram of the top-view structure of the battery pack lower case in Figure 3, and Figure 7 is a schematic diagram of the detailed structure of the water inlet and outlet in Figure 3. Referring to Figures 3 and 4, the battery pack lower case 100 includes a liquid cooling plate 10 and a plurality of side panels 20 surrounding the liquid cooling plate 10. The plurality of side panels 20 form a receiving cavity 101 around the liquid cooling plate 10. The receiving cavity 101 is used to accommodate battery cells. The liquid cooling plate includes the liquid cooling plate 10 of one of the aforementioned embodiments. In this way, by arranging multiple main liquid cooling channels 60 and auxiliary liquid cooling channels 70 in the liquid cooling plate 10 of the lower box 100 of the battery pack, an integrated design of the liquid cooling plate 10 and the lower box 100 of the battery pack is achieved, thereby eliminating the need to install a separate liquid cooling plate, improving the space utilization of the battery pack, and further improving the energy density of the battery pack.

[0046] The side panel 20 includes a left side panel 21 and a right side panel 22 that are arranged opposite to each other, and a front panel 23 and a rear panel 24 connected between the left side panel 21 and the right side panel 22. The left side panel 21 and the right side panel 22 both extend along a first direction X, and the front panel 23 and the rear panel 24 both extend along a second direction Y.

[0047] The front panel 23 is provided with a first window 231, and the rear panel 24 is provided with a second window 241. The orthographic projection of the second window 241 on the front panel 23 coincides with the first window 231, meaning that the first window 231 and the second window 241 are of the same size. The first window 231 is formed by an opening in the front panel 23, and the second window 241 is formed by an opening in the rear panel 24. Both the first window 231 and the second window 241 are used for battery pack maintenance.

[0048] The front panel 23 is also provided with a connector mounting plate 232, which protrudes from the front panel 23 and is integrally provided with the front panel 23. The connector mounting plate 232 is used to mount panel connectors, such as high-voltage connectors. Optionally, the connector mounting plate 232 is integrally formed with the front panel 23 using a stamping and embossing process. In this way, the connector mounting plate 232 is formed in a single step, eliminating the need for secondary processing. This ensures the consistency and high precision of the geometric dimensions and surface quality of the connector mounting plate 232, and also enhances the rigidity of the connector mounting plate 232, improving the stability of the structure.

[0049] The battery pack lower box 100 also includes a frame beam 30 surrounding the liquid cooling plate 10, and the side plate 20 is connected to the liquid cooling plate 10 through the corresponding frame beam 30. The frame beam 30 is used to reinforce the structure of the battery pack lower box 100. The frame beam 30 includes a left frame beam 31 and a right frame beam 32 arranged opposite to each other, and a front frame beam 33 and a rear frame beam 34 connected between the left frame beam 31 and the right frame beam 32. The multiple cavity walls of the liquid cooling plate 10 are respectively connected to the corresponding frame beams 30, such as the left cavity wall 13 is connected to the left frame beam 31, the right cavity wall 14 is connected to the right frame beam 32, the front cavity wall 15 is connected to the front frame beam 33, and the rear cavity wall 16 is connected to the rear frame beam 34. The left frame beam 31 and the right frame beam 32 both extend along the first direction X, and the front frame beam 33 and the rear frame beam 34 both extend along the second direction Y. The left side panel 21 is connected to the liquid cooling plate 10 via the left side frame beam 31 , the right side panel 22 is connected to the liquid cooling plate 10 via the right side frame beam 32 , the front panel 23 is connected to the liquid cooling plate 10 via the front frame beam 33 , and the rear panel 24 is connected to the liquid cooling plate 10 via the rear frame beam 34 .

[0050] The battery pack lower case 100 also includes a plurality of reinforcing beams 40 disposed on the liquid cooling plate 10 and located within the accommodating cavity 101. The reinforcing beams 40 are connected between the left frame beam 31 and the right frame beam 32. The reinforcing beams 40 are used to structurally reinforce the liquid cooling plate 10, improving its load-bearing capacity and thereby increasing the overall strength of the battery pack lower case 100. This allows the battery pack lower case 100 to accommodate more battery cells and achieve a larger battery pack. The reinforcing beams 40 are evenly distributed across the liquid cooling plate 10, and the specific number of reinforcing beams 40 can be determined based on the desired strength of the liquid cooling plate 10. For example, Figure 5 schematically illustrates three reinforcing beams 40. Two of the three reinforcing beams 40 are disposed at the ends of the liquid cooling plate 10, and the third is disposed in the middle of the liquid cooling plate 10. Of the reinforcing beams 40 disposed at the ends of the liquid cooling plate 10, one is located near the front panel 23 and the other near the rear panel 24. Optionally, the liquid cooling plate 10 , the side plate 20 , the frame beam 30 and the reinforcing beam 40 may be welded together using aluminum extruded profiles to form the battery pack lower box 100 .

[0051] Optionally, the battery pack lower box 100 further includes a plurality of hoisting structures 311 provided on the side of the left frame beam 31 and the side of the right frame beam 32, and the hoisting structures 311 are used for hoisting the battery pack. Optionally, the hoisting structure 311 can be formed by providing hoisting holes on the left frame beam 31 and the right frame beam 32. The cross-sectional shape of the hoisting hole is a convex shape, which has a simple structure and can improve the stability of the hoisting. In addition, the hoisting structure 311 is provided corresponding to the reinforcing beam 40, that is, the hoisting structure 311 is provided at the position where the reinforcing beam 40 is connected to the left frame beam 31 and the right frame beam 32, so as to improve the load-bearing capacity of the hoisting structure 311. The number of the lifting structures 311 provided on the left frame beam 31 and the right frame beam 32 may be equal to the number of the reinforcing beams 40. For example, if the number of the reinforcing beams 40 is three, then the number of the lifting structures 311 on the left frame beam 31 is also three, and the number of the lifting structures 311 on the right frame beam 32 is also three.

[0052] The battery pack lower case 100 also includes a plurality of mounting and fixing holes 312 provided on the left frame beam 31 and the right frame beam 32. The mounting and fixing holes 312 are located at the ends of the left frame beam 31 and the right frame beam 32 and are used to fix the battery pack lower case 100. For example, the battery pack lower case 100 can be fixed by passing a fixing bolt through the mounting and fixing holes 312. Specifically, referring to Figures 5 and 6, one of the two through holes 313 is close to the front frame beam 33, and the other is close to the rear frame beam 34. The through hole 313 passes through the corresponding left frame beam 31 or the right frame beam 32. Each of the mounting and fixing holes 312 is embedded in a through hole 313 and is fixedly connected to the left frame beam 31 or the right frame beam 32. For example, the mounting and fixing holes 312 can be fixedly connected to the left frame beam 31 or the right frame beam 32 using a welding process. The structural strength of the mounting holes 312 is greater than that of the left and right frame beams 31, 32, thereby improving the overall mounting strength of the battery pack lower case 100 and, in turn, enhancing the stability of the mounting. Furthermore, by providing the mounting holes 312 at both ends of the left and right frame beams 31, 32, the front and rear ends of the battery pack lower case 100 are secured, thereby ensuring the reliability of the battery energy storage system during transport with the batteries.

[0053] Furthermore, the battery pack lower box 100 also includes a water inlet nozzle 51 and a water outlet nozzle 52, and a water inlet connecting block 53 and a water outlet connecting block 54 respectively connected to the water inlet nozzle 51 and the water outlet nozzle 52. The water inlet connecting block 53 and the water outlet connecting block 54 are both connected to the liquid cooling plate 10 through the front frame beam 33. The water inlet nozzle 51 is connected to the water inlet on the liquid cooling plate 10 through the water inlet connecting block 53, and the water outlet nozzle 52 is connected to the water outlet on the liquid cooling plate 10 through the water outlet connecting block 54.

[0054] Referring to Figure 7, the water inlet nozzle 51 and the water outlet nozzle 52 both include a first sub-portion 511 and a second sub-portion 512 and a corner portion 513 connected between the first sub-portion 511 and the second sub-portion 512. The first sub-portion 511 is connected to the second sub-portion 512 through the corner portion 513. The surface of the corner portion 513 is an arc surface, and the first sub-portion 511 and the second sub-portion 512 intersect to form a first angle. The first angle is not equal to 90 degrees to avoid interference between the water inlet nozzle 51 and the water outlet nozzle 52 and the operation of the panel connector and the fixing bolts.

[0055] In one embodiment, the present application also provides a battery pack, which includes the battery pack lower box 100 of one of the aforementioned embodiments, and the battery pack also includes a plurality of battery cells and a box cover. The plurality of battery cells are assembled in the accommodating cavity 101 of the battery pack lower box 100, and the box cover cooperates with the side panel 20 of the battery pack lower box 100 to seal the battery pack.

[0056] In one embodiment, the present application also provides an energy storage system, which includes the battery pack of the aforementioned embodiment, and further includes a battery rack and a battery cluster, wherein the battery pack is mounted and fixed on the battery cluster, and the battery cluster is mounted and fixed on the battery rack.

[0057] The above is a detailed introduction to the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for those skilled in the art, based on the ideas of the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A liquid cooling plate (10), wherein: It comprises a main liquid cooling channel (60) and an auxiliary liquid cooling channel (70), wherein each of the main liquid cooling channel (60) and the auxiliary liquid cooling channel (70) has one end connected to a liquid inlet (151) of the liquid cooling plate (10), and the other end of the auxiliary liquid cooling channel (70) is connected to the middle of the main liquid cooling channel (60).

2. The liquid cooling plate (10) according to claim 1, wherein: The middle portion of the main liquid cooling channel (60) is 1 / 2 to 9 / 10 of the total channel length of the main liquid cooling channel (60).

3. The liquid cooling plate (10) according to claim 2, wherein: The main liquid cooling channel (60) comprises a plurality of main channels (61) extending along a first direction, the plurality of main channels (61) being arranged at intervals along a second direction, the first direction and the second direction being different, and two adjacent main channels (61) being connected to each other; The auxiliary liquid cooling channel (70) is located on the peripheral side of the main liquid cooling channel (60), and the auxiliary liquid cooling channel (70) comprises a first auxiliary channel (71) and a second auxiliary channel (72) which are connected to each other, the first auxiliary channel (71) extending along the first direction, and the second auxiliary channel (72) extending along the second direction; The liquid cooling plate (10) is further provided with a liquid outlet (152), the main liquid cooling channel (60) further comprises a first-type main channel (60-1) and a second-type main channel (60-2) which are arranged adjacent to each other, the second-type main channel (60-2) being located on a side of the first-type main channel (60-1) away from the first auxiliary channel (71), the first-type main channel (60-1) and the second-type main channel (60-2) both comprising a plurality of the main channels (61), the liquid inlet end of the first-type main channel (60-1) being adjacent to the liquid inlet (151) ), the liquid outlet end of the first-type main channel (60-1) is connected to the liquid inlet end of the second-type main channel (60-2), the liquid outlet end of the second-type main channel (60-2) is connected to the liquid outlet port (152), the liquid inlet end of the first auxiliary channel (71) is connected to the liquid inlet port (151), the liquid outlet end of the first auxiliary channel (71) is connected to the liquid inlet end of the second auxiliary channel (72), and the liquid outlet end of the second auxiliary channel (72) is connected to an end of the second-type main channel (60-2) away from the liquid outlet port (152).

4. The liquid cooling plate (10) according to claim 3, wherein: The liquid cooling plate (10) further comprises a first partition (111), a second partition (112) and a third partition (113), wherein the first partition (111) extends along the first direction and is located between the first-type main channel (60-1) and the second-type main channel (60-2); the second partition (112) extends along the first direction and is located between the first-type main channel (60-1) and the first auxiliary channel (71); the third partition (113) extends along the second direction and is located on a side of the first-type main channel (60-1) away from the liquid inlet (151), and the third partition (113) comprises a connecting portion (1131), wherein the connecting portion (1131) is connected between the first partition (111) and the second partition (112).

5. The liquid cooling plate (10) according to claim 4, wherein: The third partition (113) also includes an extension portion (1132), and the extension portion (1132) extends along the second direction from one end of the connecting portion (1131) away from the second partition (112), and the extension portion (1132) is located on a side of the second type of main channel (60-2) away from the liquid outlet (152), and a plurality of openings (161) are provided on the extension portion (1132), and the second auxiliary channel (72) is connected to the second type of main channel (60-2) through the opening (161).

6. The liquid cooling plate (10) according to claim 5, wherein: The liquid cooling plate (10) further comprises a plurality of fourth partitions (114), wherein the fourth partitions (114) extend along the first direction and are located between two adjacent main channels (61), wherein M fourth partitions (114) are arranged in the first type of main channel (60-1), and N fourth partitions (114) are arranged in the second type of main channel (60-2), and both M and N are odd numbers greater than or equal to 1.

7. The liquid cooling plate (10) according to claim 6, wherein: The first partition plate (111) is located in the middle area of ​​the liquid cooling plate (10), and the width of the first partition plate (111) in the second direction is greater than the width of the fourth partition plate (114) in the second direction.

8. The liquid cooling plate (10) according to claim 6, wherein: The liquid cooling plate (10) further comprises an upper cavity wall (11) and a lower cavity wall (12) arranged opposite to each other, and a left cavity wall (13), a right cavity wall (14), a front cavity wall (15) and a rear cavity wall (16) connected between the upper cavity wall (11) and the lower cavity wall (12) and surrounding the upper cavity wall (11) and the lower cavity wall (12); the left cavity wall (13) and the right cavity wall (14) are arranged opposite to each other, the front cavity wall (15) and the rear cavity wall (16) are both connected between the left cavity wall (13) and the right cavity wall (14), and the liquid inlet (151) and the liquid outlet (152) are both located on the front cavity wall (15); The first partition plate (111), the second partition plate (112), the third partition plate (113) and the fourth partition plate (114) are all connected between the upper cavity wall (11) and the lower cavity wall (12); the fourth partition plate (114) is located between the first partition plate (111) and the second partition plate (112); the second partition plate (112) is located between the fourth partition plate (114) and the left cavity wall (13); and the third partition plate (113) is located between the fourth partition plate (114) and the rear cavity wall (16); One end of the first partition plate (111) is connected to the third partition plate (113), and a gap exists between the other end and the front cavity wall (15); among the M fourth partition plates (114), one end of the Pth fourth partition plate (114) is connected to the front cavity wall (15), and a gap exists between the other end and the third partition plate (113); one end of the fourth partition plate (114) adjacent to the Pth fourth partition plate (114) is connected to the front cavity wall (15), and a gap exists between the other end and the third partition plate (113); ) are connected; wherein P is an odd number greater than or equal to 1, and P≤M; among the N fourth partitions (114), one end of the Qth fourth partition (114) is connected to the front cavity wall (15), and a gap exists between the other end and the third partition (113); one end of the fourth partition (114) adjacent to the Qth fourth partition (114) has a gap between it and the front cavity wall (15), and the other end is connected to the third partition (113); wherein Q is an odd number greater than or equal to 1, and Q≤N.

9. The liquid cooling plate (10) according to claim 8, wherein: The liquid cooling plate (10) further comprises a plurality of fifth partitions (115) arranged in each of the main channels (61), wherein the plurality of fifth partitions (115) extend along the first direction and are arranged at intervals along the second direction, and the plurality of fifth partitions (115) divide each of the main channels (61) into a plurality of sub-channels (601); a gap exists between one end of each of the fifth partitions (115) and the front cavity wall (15), and a gap exists between the other end and the rear cavity wall (16).

10. According to the liquid cooling plate (10) of claim 8, the left cavity wall (13), the right cavity wall (14), the front cavity wall (15) and the rear cavity wall (16) are connected end to end and surround the upper cavity wall (11) and the lower cavity wall (12) to form a cavity structure (110), and the main liquid cooling channel (60) and the auxiliary liquid cooling channel (70) are formed in the cavity structure (110).

11. A battery pack lower box (100), wherein: It comprises a liquid cooling plate (10) according to any one of claims 1 to 9, and a plurality of side plates (20) surrounding the liquid cooling plate (10), wherein the plurality of side plates (20) surround the liquid cooling plate (10) to form a receiving cavity (101).

12. The battery pack lower box (100) according to claim 11, wherein: The side panel (20) comprises a left side panel (21) and a right side panel (22) which are arranged opposite to each other, and a front panel (23) and a rear panel (24) which are connected between the left side panel (21) and the right side panel (22); the left side panel (21) and the right side panel (22) both extend along the first direction, and the front panel (23) and the rear panel (24) both extend along the second direction; The battery pack lower box (100) further comprises a left frame beam (31) and a right frame beam (32) arranged opposite to each other, and a front frame beam (33) and a rear frame beam (34) connected between the left frame beam (31) and the right frame beam (32); the left side panel (21) is connected to the liquid cooling plate (10) via the left frame beam (31); the right side panel (22) is connected to the liquid cooling plate (10) via the right frame beam (32); the front panel (23) is connected to the liquid cooling plate (10) via the front frame beam (33); and the rear panel (24) is connected to the liquid cooling plate (10) via the rear frame beam (34).

13. The battery pack lower box (100) according to claim 12, wherein: The battery pack lower box (100) further comprises a plurality of reinforcing beams (40) arranged on the liquid cooling plate (10) and located in the accommodating cavity (101), the reinforcing beams (40) being connected between the left frame (31) and the right frame beam (32); A plurality of hoisting structures (311) are provided on the side surface of the left frame beam (31) and the side surface of the right frame beam (32), and the hoisting structures (311) are provided corresponding to the reinforcing beam (40).

14. The battery pack lower box (100) according to claim 12, wherein: At least two through holes (313) are provided on each of the left frame beam (31) and the right frame beam (32), one of the two through holes (313) being close to the front frame beam (33) and the other being close to the rear frame beam (34); The battery pack lower box (100) further comprises a plurality of mounting and fixing sleeve holes (312), each of the mounting and fixing sleeve holes (312) being embedded in one of the through holes (313) and fixedly connected to the left frame beam (31) or the right frame beam (32).

15. The battery pack lower box (100) according to claim 12, wherein: The battery pack lower box (100) further comprises a water inlet nozzle (51) and a water outlet nozzle (52), and a water inlet connection block (53) and a water outlet connection block (54) respectively connected to the water inlet nozzle (51) and the water outlet nozzle (52); the water inlet connection block (53) and the water outlet connection block (54) both pass through the front frame beam (33) and the frame beam (30) to be connected to the liquid cooling plate (10); the water inlet nozzle (51) is connected to the water inlet on the liquid cooling plate (10) through the water inlet connection block (53); and the water outlet nozzle (52) is connected to the water outlet on the liquid cooling plate (10) through the water outlet connection block (54).

16. The battery pack lower box (100) according to claim 15, wherein: The water inlet nozzle (51) and the water outlet nozzle (52) both comprise a first sub-portion (511), a second sub-portion (512), and a corner portion (513) connected between the first sub-portion (511) and the second sub-portion (512); the first sub-portion (511) is connected to the second sub-portion (512) via the corner portion (513); the surface of the corner portion (513) is an arc surface; the first sub-portion (511) and the second sub-portion (512) intersect to form a first angle; the first angle is not equal to 90 degrees.

17. The battery pack lower box (100) according to claim 12, wherein: The front panel (23) is provided with a first window (231), the rear panel (24) is provided with a second window (241), and the orthographic projection of the second window (241) on the front panel (23) overlaps with the first window (231).

18. The battery pack lower box (100) according to claim 12, wherein: A connector mounting plate (232) is also provided on the front panel (23); the connector mounting plate (232) protrudes outward from the front panel (23), and the connector mounting plate (232) and the front panel (23) are integrally provided.

19. A battery pack, wherein: It comprises a battery pack lower box (100) as claimed in any one of claims 11 to 18.

20. An energy storage system, wherein: Comprising the battery pack as claimed in claim 19.

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