Immersed direct liquid cooling energy storage battery pack

Abstract

The utility model discloses an immersed direct liquid cooling energy storage battery pack, which relates to the technical field of energy storage batteries and comprises a cold plate at the bottom, a box cover covering the cold plate and a battery pack positioned in a box body covered by the cold plate and the box cover, cooling liquid is injected into the box body, and the battery pack is in direct contact with the cooling liquid; a first flow channel for cooling liquid to circulate is arranged in the cold plate; the battery pack comprises a plurality of battery core groups, gaps for cooling liquid to circulate are formed between adjacent battery core groups and form third flow channels, each battery core group comprises a plurality of single battery cores, heat insulation pads are arranged between adjacent single battery cores, the gaps between the heat insulation pads and the battery cores can allow the cooling liquid to circulate and form second flow channels, and the bottom ends of the second flow channels are communicated with the first flow channels; and the left and right sides are communicated with the third runner. Compared with a single-liquid-inlet serial flow channel scheme in the prior art, a mode of supplying liquid into the battery box body in parallel from the secondary liquid inlet through the bottom cold plate can effectively reduce the temperature difference between battery cells. The heat insulation pads arranged between the adjacent single battery cells can delay heat spreading.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage batteries, and more specifically to an immersion type direct liquid-cooled energy storage battery pack. Background Art

[0002] Energy storage battery packs are a type of power source that stores electrical energy and then extracts it for use during peak periods of electricity use or when the external power supply system is disconnected. With the continuous development of society, energy storage battery packs are increasingly being used in areas such as communication base station energy storage, household energy storage, and industrial and commercial energy storage.

[0003] In the prior art, the patent with publication number CN219658795U discloses an immersion liquid-cooled battery pack, which relates to the field of battery technology. The technical problems that this patent hopes to solve are battery temperature control and thermal safety. A plurality of battery packs are fixedly arranged in the box, and a first channel for coolant to pass through is provided between two adjacent battery packs. The battery pack includes two rows of battery cell groups, and each row of battery cell groups includes a plurality of single battery cells. A second channel for coolant to pass through is provided between two adjacent single battery cells. The coolant exchanges heat with the battery cell through the first and second channels. This utility model patent has the problems of uneven heat exchange and low heat exchange efficiency. On the one hand, the coolant is a serial flow channel from the inlet to the outlet, and the temperature of the coolant near the outlet will increase, increasing the temperature difference of the battery pack. On the other hand, the surfaces of the single battery cells in the thickness direction are in contact with each other, reducing the effective heat exchange area between the coolant and the battery cell.

[0004] The patent with publication number CN116666826A discloses an immersion liquid-cooled battery pack structure, which relates to the field of energy storage technology. This patent hopes to improve the overall heat exchange capacity of the battery pack, reduce the temperature of the battery cells, and improve temperature uniformity and safety. It includes a shell, a battery cell, a battery cell busbar, an end plate, an inlet pipe, an outlet pipe, an upper cover, a coolant diverter plate, an inlet manifold, and an outlet manifold, wherein the coolant diverter plate is arranged between two rows of battery cells, and an opening is arranged on the coolant diverter plate. The position of the opening corresponds to the gap between two adjacent battery cells in a row of battery cells, and the insulating coolant flows from the hole into the gap between the battery cells to achieve heat exchange between the large surface and side of the coolant and the battery cell. This invention patent has two disadvantages. ① The heat exchange between the coolant and the battery cell is uneven. In this patent, the coolant adopts a front-to-back outlet solution. The temperature of the coolant near the outlet increases, which will cause the temperature unevenness of the entire battery pack to increase. ② The heat exchange efficiency between the coolant and the battery cell is not high. The diversion holes of the coolant diverter plate are set on the "small side" of the battery cell. The diversion direction of the coolant to the diversion holes is perpendicular to the direction of the coolant main channel (front and back direction). The coolant flow rate entering the "large surface" of the battery cell from the diversion holes is very low, and the heat exchange efficiency is not high. Utility Model Content

[0005] In order to overcome the defects existing in the above-mentioned prior art, the purpose of the present invention is to provide an immersion type direct liquid-cooled energy storage battery pack to solve the temperature control and thermal safety problems of the existing battery energy storage system, specifically: (1) reducing the temperature difference between the battery cells themselves and between batteries; (2) delaying the thermal runaway process of the battery.

[0006] In order to achieve the above objectives, the technical solution adopted by the utility model is:

[0007] An immersion type direct liquid cooling energy storage battery pack comprises a cold plate at the bottom, a box cover covering the cold plate, and a battery pack located in a box body covered by the cold plate and the box cover;

[0008] The box body is filled with coolant, and the battery pack is in direct contact with the coolant; a first flow channel for the circulation of coolant fluid is arranged in the cold plate; the battery pack includes a plurality of battery cell groups, and gaps for the circulation of coolant fluid are arranged between adjacent battery cell groups to form a third flow channel; the battery cell group includes a plurality of single battery cells, and gaps for the circulation of coolant fluid are arranged between adjacent single battery cells to form a second flow channel, the bottom end of the second flow channel is connected with the first flow channel, and the left and right sides are connected with the third flow channel; the coolant enters the second flow channel upward through the first flow channel, and then enters the left and right third flow channels to cool the single battery cells in the second flow channel and the third flow channel.

[0009] Preferably, a horizontal cavity is provided inside the cold plate to form the first flow channel; a main liquid inlet connected to the first flow channel is also provided on the cold plate, and the main liquid inlet is connected to an external liquid supply system.

[0010] Preferably, the cold plate is provided with a plurality of secondary liquid inlets connected with a plurality of second flow channels between adjacent single battery cells, and the plurality of secondary liquid inlets are all connected to the first flow channel.

[0011] Preferably, the width of the secondary liquid inlet is the same as the width of the gap between two adjacent single battery cells.

[0012] Preferably, in the battery cell group, a plurality of thermal insulation pads are arranged between two adjacent single battery cells, and the area between the two adjacent single battery cells and the plurality of thermal insulation pads forms the second flow channel.

[0013] Preferably, a coolant outlet is provided on the box cover, and the coolant outlet is connected to an external pipeline system.

[0014] Beneficial effects of the utility model:

[0015] The utility model provides an immersion-type direct liquid-cooled energy storage battery pack, in which the bottom cold plate and the bottom plate of the box are combined into one, which plays the role of liquid supply and support. Compared with the existing immersion cooling battery pack patent, the utility model is a newly added structure. The method of parallel liquid supply from the secondary liquid inlet to the battery box through the bottom cold plate, compared with the existing single liquid inlet serial flow channel solution, the bottom cold plate structure design of the utility model can effectively reduce the temperature difference between battery cells.

[0016] The utility model provides an immersion type direct liquid cooling energy storage battery pack, in which a plurality of heat insulation pads are arranged between two adjacent single cells. Compared with the existing immersion type technical scheme, the utility model is a newly added structure. On the one hand, the coolant is in direct contact with the "large surface" of the cell, and the special-shaped second flow channel formed between the plurality of heat insulation pads and the "large surface" of the cell enhances the heat exchange efficiency between the coolant and the cell; on the other hand, this structure avoids direct contact between the cells, and can delay the spread of heat when a single cell has thermal runaway. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the external structure of the immersion direct liquid-cooled energy storage battery pack of the utility model;

[0018] Figure 2 This is a schematic diagram of the internal structure of the immersion direct liquid-cooled energy storage battery pack of the utility model;

[0019] Figure 3 This is a schematic diagram of the bottom cold plate structure of the utility model;

[0020] Figure 4 It is a schematic diagram of the heat insulation pad between the single battery cells of the utility model;

[0021] Figure 5 This is a schematic diagram of the coolant flow direction principle of the immersion liquid cooling of the utility model;

[0022] Reference numerals:

[0023] 1. Cold plate; 11. Main liquid inlet; 12. Secondary liquid inlet; 2. Box cover; 21. Coolant outlet; 3. Battery pack; 31. Cell pack; 32. Single cell; 33. Thermal insulation pad; 4. First flow channel; 5. Second flow channel; 6. Third flow channel. DETAILED DESCRIPTION

[0024] The concept, specific structure and technical effects of the present invention will be clearly and completely described below in combination with the embodiments and drawings to fully understand the purpose, features and effects of the present invention.

[0025] An immersion type direct liquid cooling energy storage battery pack, such as Figure 1-5As shown, it includes a cold plate 1 at the bottom, a box cover 2 covering the cold plate 1, and a battery pack 3 located in a box body covered by the cold plate 1 and the box cover 2;

[0026] The box body is filled with coolant, and the battery pack 3 is in direct contact with the coolant; a first flow channel 4 for the coolant fluid to circulate is arranged in the cold plate 1; the battery pack 3 includes a plurality of battery cell groups 31, and gaps for the coolant fluid to circulate are arranged between adjacent battery cell groups 31 to form a third flow channel 6; the battery cell group 31 includes a plurality of single battery cells 32, and gaps for the coolant fluid to circulate are arranged between adjacent single battery cells 32 to form a second flow channel 5, and the bottom end of the second flow channel 5 is connected to the first flow channel 4, and the left and right sides are connected to the third flow channel 6; the coolant enters the second flow channel 5 upward through the first flow channel 4, and then enters the left and right third flow channels 6 to cool the single battery cells 32 in the second flow channel 5 and the third flow channel 6.

[0027] In this embodiment, the key structures of the battery pack include a box cover 2, a battery pack 3, a bottom cold plate 1, and some seals. The box body composed of the box cover 2 and the cold plate 1 is filled with coolant, and the battery pack 3 is in direct contact with the coolant. The battery pack 3 includes at least one battery cell group 31, and a fixed gap is provided between the battery cell groups 31. The battery cell group 31 is composed of a plurality of single battery cells 32. There is also a fixed gap between the single battery cells 32 and the single battery cells 32 in the battery cell group 31, and the gap formed can be used for the circulation of coolant. The bottom cold plate 1 is provided with a main liquid inlet 11 and a secondary liquid inlet 12 for coolant, and the main liquid inlet 11 is connected to the external liquid supply system. Two coolant outlets 21 are provided on the box cover 2, and the outlets are also connected to the external piping system. The coolant can circulate in the box to take away the heat generated by the battery pack.

[0028] like Figure 4 As shown, in the battery cell group 31 , a plurality of thermal insulation pads 33 are arranged between two adjacent single battery cells 32 , and the area between the two adjacent single battery cells 32 and the plurality of thermal insulation pads 33 forms a second flow channel 5 .

[0029] Usually, a plurality of single cells 32 are bundled together with steel strips or other materials having the same function to form a cell group 31, such as Figure 2 As shown, the number of single cells 32 in the battery pack in this embodiment is not quantitatively specified in this article, and all belong to the protection content of this patent. In the same cell group 31, a heat insulation pad 33 is provided between the cells and the "large surface" of the cells. The projection area of ​​the heat insulation pad 33 on the "large surface" of the cell is smaller than the area of ​​the "large surface" of the cell. Figure 4 The heat insulation pad 33 has two main functions: ① forming a special-shaped second flow channel 5 between the multiple heat insulation pads and the "large surface" of the battery cell ( Figure 5 ), the coolant flows through the second flow channel 5, cools the "large surface" of the battery cell, and takes away the heat of the battery cell. ② Avoid direct contact between battery cells, which can delay the spread of heat when a single battery cell has thermal runaway.

[0030] The structure of the bottom cold plate 1 is shown as follows Figure 3 As shown, the bottom cold plate 1 is provided with a main liquid inlet 11 and a secondary liquid inlet 12, and a cavity is provided inside to form a first flow channel 4. The width of the secondary liquid inlet is consistent with the width of the gap formed between the battery cells, and the secondary liquid inlet is connected to the second flow channel 5. The bottom cold plate 1 has two main functions: ① liquid supply and flow balance; ② the bottom cold plate and the bottom plate of the box are combined into one to support the battery cells.

[0031] The schematic diagram of the coolant flow direction is as follows Figure 5 , "×" represents the secondary liquid inlet 12 of the cold plate. The coolant first enters the bottom cold plate 1 through the first flow channel 4, and after filling the bottom cold plate 1, it flows upward through the special-shaped second flow channel 5 formed between the insulation pad 33 and the "large surface" of the battery cell from the secondary liquid inlet 12, and finally flows to the liquid outlet through the third flow channel 6 formed by the gap between the battery cell groups. In the first flow channel 4 inside the bottom cold plate, there is almost no temperature difference of the coolant. Therefore, the temperature of the coolant when entering the second flow channel 5 from each secondary liquid inlet 12 of the bottom cold plate is basically the same. Therefore, this parallel flow channel setting can reduce the temperature difference of each battery cell in the battery pack. The coolant can directly contact the four surfaces of the battery cell for heat exchange, and thanks to the design of the secondary liquid inlet, the overall flow direction of the coolant in the battery box is from bottom to top, and the flow rate in the second flow channel 5 of the "large surface" of the battery cell is fast, which greatly improves the heat exchange efficiency between the coolant and the battery cell.

[0032] In particular, the thickness, area, and location of the thermal insulation pad on the "large surface" of the battery cell can be optimized and determined based on the simulation results, and this article does not make quantitative regulations. The width of the secondary liquid inlet is consistent with the thickness of the thermal insulation pad, and in order to ensure uniform flow of each secondary liquid inlet, it can be optimized based on the simulation results, and the length of each secondary liquid inlet can be different.

[0033] Compared with the prior art, the immersed direct liquid-cooled energy storage battery pack provided in this embodiment has the following advantages:

[0034] 1. Small temperature difference between the battery cell and the battery cells: Compared with the heat transfer path from the battery cell to the cold plate and then to the coolant in the indirect cold plate liquid cooling [CN219759723U], the immersion direct liquid cooling solution of this patent directly contacts the coolant, the temperature difference of the battery cell itself is small, and the heat exchange efficiency is high. In the patent [CN116666826A], the serial flow channel solution of the coolant is forward and backward, and the parallel flow channel design of the secondary liquid inlet proposed in this patent can greatly reduce the temperature difference between the battery cells.

[0035] 2. High heat exchange efficiency between coolant and battery cells: In the patent [CN219658795U], in the same battery cell group, the surfaces of the single battery cells are in contact with each other in the thickness direction. The utility model adopts a structural design of arranging multiple insulation pads on the "large surface" of the battery cell, so that the coolant can directly contact and exchange heat with the four surfaces of the battery cell. In addition, thanks to the design of the secondary liquid inlet, the overall flow direction of the coolant in the battery box is from bottom to top, and the flow rate between the "large surfaces" of the battery cell is fast, which greatly improves the heat exchange efficiency between the coolant and the battery cell.

[0036] 3. High thermal safety: In the patent [CN219658795U], the surfaces of the single cells in the same cell group are in contact with each other in the thickness direction. This patent proposes a design of setting multiple small insulation pads on the "large surface" of the cell to avoid direct contact between the cells. When a single cell has thermal runaway, it can delay the spread of heat and improve safety.

[0037] 4. The installation process is simpler: This patent achieves uniform distribution of coolant through the bottom cold plate structure, insulation pad and other structural designs, eliminating the need for pipeline installation and pairing. The installation and assembly process of this patent is relatively simple.

[0038] The implementation methods of the present invention are described in detail above, but the present invention is not limited to the described embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention, and these equivalents or substitutions are all included in the scope defined by the claims of the present invention.

Claims

1. An immersion type direct liquid cooling energy storage battery pack, characterized in that: It comprises a cold plate (1) at the bottom, a box cover (2) covering the cold plate (1), and a battery pack (3) located in a box body covered by the cold plate (1) and the box cover (2); The box is filled with cooling liquid, and the battery pack (3) is in direct contact with the cooling liquid; a first flow channel (4) for the cooling liquid to flow is provided in the cold plate (1); the battery pack (3) comprises a plurality of battery cell groups (31), gaps for the cooling liquid to flow are provided between adjacent battery cell groups (31) to form a third flow channel (6); the battery cell group (31) comprises a plurality of single battery cells (32), gaps for the cooling liquid to flow are provided between adjacent single battery cells (32) to form a second flow channel (5), the bottom end of the second flow channel (5) is connected to the first flow channel (4), and the left and right sides are connected to the third flow channel (6); the cooling liquid flows upward through the first flow channel (4) into the second flow channel (5), and then into the left and right third flow channels (6), so as to cool the single battery cells (32) in the second flow channel (5) and the third flow channel (6).

2. The energy storage battery pack according to claim 1, characterized in that: A horizontal cavity is provided inside the cold plate (1) and forms the first flow channel (4); a main liquid inlet (11) connected to the first flow channel (4) is also provided on the cold plate (1), and the main liquid inlet (11) is connected to an external liquid supply system.

3. The energy storage battery pack according to claim 1, characterized in that: The cold plate (1) is provided with a plurality of secondary liquid inlets (12) connected to a plurality of second flow channels (5) between adjacent single battery cells (32); the plurality of secondary liquid inlets (12) are all connected to the first flow channel (4).

4. The energy storage battery pack according to claim 3, characterized in that: The width of the secondary liquid inlet (12) is the same as the width of the gap between two adjacent single battery cells (32).

5. The energy storage battery pack according to claim 1, characterized in that: In the battery cell group (31), a plurality of thermal insulation pads (33) are provided between two adjacent single battery cells (32), and the area between the two adjacent single battery cells (32) and the plurality of thermal insulation pads (33) forms the second flow channel (5).

6. The energy storage battery pack according to claim 1, characterized in that: The box cover (2) is provided with a coolant outlet (21), and the coolant outlet (21) is connected to an external pipeline system.

Images