A lean liquid direct cooling energy storage battery pack

Abstract

The present invention discloses a lean liquid direct cooling energy storage battery pack, comprising a box body, which is filled with a low boiling point refrigerant; a battery pack, which is immersed in the low boiling point refrigerant in the box body; a condensation module, which is arranged in the box body and located above the battery pack; the battery pack comprises a plurality of first channel plates distributed at intervals and battery cells arranged between the first channel plates, a second channel plate is arranged at the bottom of the battery pack, a first channel in contact with the surface of the battery cell is arranged in the first channel plate, a second channel in contact with the surface of the battery cell is arranged in the second channel plate, a condensation reflux channel is arranged in the condensation module, at least one connecting channel for connecting the condensation reflux channel and the second channel is provided between the battery pack and the box body, and the condensation reflux channel, the connecting channel, the second channel, and the first channel are connected to form a circulation loop. The present invention allows the refrigerant to directly contact the battery, directly cools the battery through phase change heat absorption, and has a fast heat conduction speed and high cooling efficiency.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a lean liquid type direct-cooling energy storage battery pack. Background Art

[0002] The cooling design of the fully immersed energy storage battery pack achieves the purpose of cooling by immersing the entire battery in the coolant. The battery can be tightly assembled in the coolant and has gap assembly. For tight assembly, most batteries have only narrow sides in contact with the coolant, with a small heat exchange area and slow heat dissipation. For gap assembly, the contact between the battery and the coolant is better, but the battery pack grouping efficiency is relatively low, the space utilization rate is relatively low, and the volume energy density is also relatively low. At the same time, the coolant is in a flowing state inside the battery pack, which is easy to shake, leak, and hit, posing a major safety hazard. The coolant will not undergo phase change, but mainly absorbs sensible heat and has a small amount of heat absorption. On the one hand, a large amount of coolant is required to absorb the heat generated by the battery, which easily leads to a low volume energy density of the battery pack. On the other hand, it cannot quickly absorb the heat generated by the battery, and the cooling effect is limited. Summary of the invention

[0003] 1. Technical problem to be solved by the invention

[0004] In view of the technical problems of poor battery cooling effect and low battery pack grouping efficiency in the prior art, the present invention provides a lean liquid direct-cooling energy storage battery pack, which utilizes the large heat absorption of the refrigerant phase change to allow the refrigerant to directly contact the battery, and directly cool the battery through phase change heat absorption, with fast heat conduction speed and high cooling efficiency.

[0005] 2. Technical solution

[0006] To solve the above problems, the technical solution provided by the present invention is:

[0007] A lean liquid direct-cooling energy storage battery pack comprises a box body filled with a low-boiling-point refrigerant; a battery pack immersed in the low-boiling-point refrigerant inside the box body; a condensing module arranged in the box body and located above the battery pack; the battery pack comprises a plurality of first channel plates distributed at intervals and battery cells arranged between the first channel plates, a second channel plate is arranged at the bottom of the battery pack, a first channel in contact with the surface of the battery cell is arranged in the first channel plate, a second channel in contact with the surface of the battery cell is arranged in the second channel plate, a condensing reflux channel is arranged in the condensing module, at least one connecting channel for connecting the condensing reflux channel and the second channel is provided between the battery pack and the box body, the condensing reflux channel, the connecting channel, the second channel and the first channel are connected to form a circulation loop.

[0008] Optionally, both the first channel plate and the second channel plate are porous structures, and the first channel and the second channel are pores inside the porous structures.

[0009] Optionally, the first channel plate and the second channel plate are made of one of ceramic fiber, aerogel felt, glass fiber and asbestos cloth.

[0010] Optionally, the condensation module includes a reflux pipe and a cooling pipe, heat exchange can be carried out between the reflux pipe and the cooling pipe, the condensation reflux channel is an internal channel of the reflux pipe, a cooling medium is arranged in the cooling pipe, an inlet for connecting the condensation reflux channel and the first channel is arranged at the lower end of the reflux pipe, and an outlet for connecting the condensation reflux channel and the connecting channel is arranged at the side end of the reflux pipe.

[0011] Optionally, the condensing module further comprises a reflux cover arranged above the battery pack, and the reflux pipe is installed in the reflux cover.

[0012] Optionally, the low boiling point refrigerant is one of organic substances such as halogenated alkanes, ketones, ethers or alkanes.

[0013] Optionally, one connecting channel is provided in each battery pack.

[0014] Optionally, the cooling medium is one of air, water, refrigerant, and ethylene glycol aqueous solution.

[0015] Optionally, two baffles are arranged in the reflux pipe, a vaporization channel is provided between the two baffles, the upper end of the vaporization channel is connected to the condensation reflux channel, the lower end of the vaporization channel is connected to the inlet, a liquefaction channel is provided between the baffle and the inner wall of the reflux pipe, the end of the liquefaction channel is connected to the connecting channel, and the inner wall of the reflux pipe is arc-shaped.

[0016] 3. Beneficial effects

[0017] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0018] (1) The low-boiling-point refrigerant is in direct contact with the battery, with low thermal resistance and fast heat conduction.

[0019] (2) Low-boiling-point refrigerant directly cools the battery and absorbs heat from the battery through phase change. The latent heat of phase change of the material is much greater than the sensible heat, so the heat transfer coefficient is high, the cooling speed is fast, the cooling efficiency is high, and the amount of refrigerant used is also small, which can improve the volume energy density and mass energy density.

[0020] (3) Low-boiling-point refrigerant has large phase change heat absorption, fast heat absorption, and flame retardancy. It can quickly absorb heat and dilute air, which can inhibit and delay thermal runaway, heat diffusion, and fire of the battery pack, thereby improving the safety of the battery pack.

[0021] (4) The low-boiling-point refrigerant phase changes and absorbs heat, resulting in small temperature changes and good battery temperature control effects.

[0022] (5) The entire cycle process can be automatically realized by the floating of bubbles after the low-boiling point refrigerant is vaporized, without the need for additional drive control, thereby reducing the generation of external heat during the cooling process and reducing the overall volume of the lean liquid direct-cooling energy storage battery pack.

[0023] (6) The present invention can increase the contact area between the battery pack and the low-boiling-point refrigerant, and can also utilize the large heat absorption capacity of the low-boiling-point refrigerant during phase change to allow the low-boiling-point refrigerant to directly contact the battery, directly cool the battery through phase change heat absorption, increase the heat conduction rate, quickly reduce the battery pack temperature, reduce the amount of low-boiling-point refrigerant required, achieve tight assembly of the battery, and increase energy density.

[0024] (7) The present invention utilizes the large heat absorption characteristic of the refrigerant during phase change, allowing the refrigerant to directly contact the battery and directly cool the battery through phase change heat absorption, thereby achieving fast heat conduction speed and high cooling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the structure of a lean liquid direct-cooling energy storage battery pack proposed in an embodiment of the present invention;

[0026] Figure 2 A schematic structural diagram of a battery pack of a lean liquid type direct-cooling energy storage battery pack proposed in an embodiment of the present invention;

[0027] Figure 3 An explosion diagram of a battery pack of a lean liquid type direct-cooling energy storage battery pack proposed in an embodiment of the present invention;

[0028] Figure 4 A schematic structural diagram of a condensing module of a lean liquid type direct-cooling energy storage battery pack proposed in an embodiment of the present invention;

[0029] Figure 5 A cross-sectional schematic diagram of a lean liquid type direct-cooling energy storage battery pack proposed in an embodiment of the present invention.

[0030] 1. Box body; 2. Battery pack; 21. First channel plate; 211. First channel; 22. Battery cell; 23. Second channel plate; 231. Second channel; 3. Condensation module; 31. Condensation reflux channel; 32. Reflux pipe; 32a. Inlet; 32b. Outlet; 321. Baffle; 3211. Gasification channel; 3212. Liquefaction channel; 33. Cooling pipe; 34. Reflux cover; 4. Connecting channel; 5. Side fixing plate; 6. End fixing plate; 7. Bottom support plate. DETAILED DESCRIPTION

[0031] To further understand the content of the present invention, Figure 1-5 The present invention is described in detail with reference to the accompanying drawings and embodiments.

[0032] Combined with Figure 1-5 A lean liquid direct cooling energy storage battery pack of the present embodiment includes a box body 1 filled with a low boiling point refrigerant; a battery pack 2 immersed in the low boiling point refrigerant inside the box body 1; a condensing module 3 arranged in the box body 1 and above the battery pack 2; the battery pack 2 includes a plurality of first channel plates 21 distributed at intervals and battery cells 22 arranged between the first channel plates 21, the first channel plates 21 and the battery cells 22 are arranged alternately in sequence along the length direction of the box body 1, the first channel plates 21 are attached to the side walls of the battery cells 22, and the bottom of the battery pack 2 A second channel plate 23 is provided in the body, a first channel 211 in contact with the surface of the battery cell 22 is provided in the first channel plate 21, a second channel 231 in contact with the surface of the battery cell 22 is provided in the second channel plate 23, a condensation reflux channel 31 is provided in the condensation module 3, and at least one connecting channel 4 for connecting the condensation reflux channel 31 and the second channel 231 is provided between the battery pack 2 and the box body 1, and the condensation reflux channel 31, the connecting channel 4, the second channel 231, and the first channel 211 are connected to form a circulation loop.

[0033] In this embodiment, the low-boiling-point refrigerant is an organic substance such as a halogenated alkane, ketone, ether or alkane, which has the characteristics of low boiling point, volatility, flame retardancy, safety and environmental protection, such as R245fa, perfluoropentane, R365mfc, R245ca, R1334mzz, perfluorohexanone, etc., or a mixture of several of them.

[0034] When the battery pack 2 is immersed in the low-boiling-point refrigerant, the low-boiling-point refrigerant will be dispersed in the second channel 231 and the first channel 211 and fully contact the surface of the battery cell 22. When the low-boiling-point refrigerant absorbs the heat from the battery cell 22, it directly cools the battery. The low-boiling-point refrigerant is heated and vaporized to form bubbles. The bubbles float up and enter the condensation reflux channel 31 of the condensation module 3 under the action of buoyancy. At the same time, the low-boiling-point refrigerant in the connecting channel 4 will be supplemented to the second channel 231 and the first channel 211 due to the liquid level difference to achieve continuous cooling. When the bubbles pass through the condensation reflux channel 31, they are cooled into small droplets. The small droplets flow along the condensation reflux channel 31 to the connecting channel 4, and flow along the connecting channel 4 into the second channel 231 of the second channel plate 23. Such a reciprocating cycle forms a heat conduction cycle of endothermic evaporation-condensation heat release. Because the low-boiling-point refrigerant absorbs a large amount of heat during the phase change process, it can quickly take away the heat from the surface of the battery cell 22. In the present invention, the first channel plate 21 is set to allow the battery cell The connection between 22 can be a fastening connection, the space utilization rate and volume energy density of the battery pack are greatly improved, and the first channel plate 21 is provided with a first channel 211 in contact with the surface of the battery cell 22, so that the low-boiling-point refrigerant can fully contact the surface of the battery cell 22 through the first channel 211, and the contact area between the low-boiling-point refrigerant and the battery cell 22 is greatly improved. The low-boiling-point refrigerant is in direct contact with the battery cell 22, with low thermal resistance and fast heat conduction; the arrangement of the second channel plate 23 and the second channel 231 facilitates the entry of the low-boiling-point refrigerant from the bottom of the battery pack 2, and the low-boiling-point refrigerant enters from the bottom of the battery pack 2, and automatically floats up into the condensation module 3 after gasification to cool into small droplets, and then the small droplets will fall along the connecting channel 4 under the action of gravity and flow back into the second channel 231, and the entire circulation process can be automatically realized by the floating of bubbles, without the need for additional drive control, reducing the generation of external heat during the cooling process, and at the same time reducing the overall volume of the lean liquid direct-cooling energy storage battery pack.

[0035] In this embodiment, the low-boiling-point refrigerant is in direct contact with the battery, with low thermal resistance and fast heat conduction; the low-boiling-point refrigerant directly cools the battery and absorbs heat from the battery through phase change. The latent heat of the phase change of the substance is much greater than the sensible heat, with a high heat transfer coefficient, fast cooling speed, high cooling efficiency, and a small amount of refrigerant, which can improve the volume energy density and mass energy density; the low-boiling-point refrigerant has a large phase change heat absorption, fast heat absorption, and is flame-retardant. It can absorb heat quickly and dilute the air, which plays a role in inhibiting and delaying thermal runaway, heat diffusion, and fire of the battery pack, and helps to improve the safety of the battery pack; the low-boiling-point refrigerant absorbs heat quickly and is flame-retardant. It can absorb heat quickly and dilute the air, which plays a role in inhibiting and delaying thermal runaway, heat diffusion, and fire of the battery pack, and helps to improve the safety of the battery pack; During the phase change heat absorption process of the refrigerant, the temperature change is small, and the battery temperature uniformity control effect is good; compared with liquid cooling, air cooling, immersion cooling, and phase change cooling technology, the present embodiment directly cools the battery cell 22 through a low-boiling-point refrigerant, without an intermediate heat conduction path and with low thermal resistance; the low-boiling-point refrigerant has a large phase change heat absorption rate, fast heat absorption, high heat transfer coefficient, good cooling effect, stable phase change temperature, and good temperature uniformity control effect; the amount of low-boiling-point refrigerant used is small, the volume energy density and mass energy density are high, and the cooling effect of the battery pack 2 can be guaranteed under the premise of reducing the amount of low-boiling-point refrigerant used.

[0036] In this embodiment, the plurality of first channel plates 21, battery cells 22 and second channel plates 23 are fastened together into a whole by side fixing plates 5, end fixing plates 6 and bottom supporting plates 7. The connecting channel 4 is a gap between the side fixing plates 5 and the inner wall of the box body 1. The end fixing plates 6 cover the side surfaces of the outermost battery cells 22 and the end surfaces of the second channel plates 23. The side fixing plates 6 only cover the side surfaces of the plurality of battery cells 22 and do not block the side surfaces of the second channel plates 23, so that the external low-boiling-point refrigerant can enter the second channel 231 through the side surfaces of the second channel plates 23.

[0037] In this embodiment, in order to improve the circulation efficiency of the low-boiling-point refrigerant in the box body 1, one connecting channel 4 is provided in each battery pack 2 to ensure that the connecting channel 4 can quickly discharge the small droplets in the condensation reflux channel 31, thereby avoiding excessive liquid in the condensation reflux channel 31 affecting the cooling and entry of bubbles.

[0038] As an optional solution of the present invention, the first channel plate 21 and the second channel plate 23 are both porous structures, and the first channel 211 and the second channel 231 are channels inside the porous structure; the porous structure has high strength and has good stability when used to connect the battery cell 22 or to support the battery pack 2, so that the entire battery pack 2 can maintain a tightly assembled state without damage. At the same time, there are more channels inside the porous structure, and the porous structure can accommodate more low-boiling point refrigerant in contact with the surface of the battery cell 2 to improve the heat exchange efficiency between the battery cell 2 and the low-boiling point refrigerant. Through a simple structural setting, the cooling effect of the lean liquid direct-cooling energy storage battery pack is doubled, and it is practical.

[0039] As an optional solution of the present invention, the material of the first channel plate 21 and the second channel plate 23 is a material with the characteristics of being compressible, flame retardant, high temperature resistant, and able to absorb coolant; in this embodiment, the material of the first channel plate 21 and the second channel plate 23 is one of ceramic fiber, aerogel felt, glass fiber, and asbestos cloth.

[0040] As an optional solution of the present invention, the condensation module 3 includes a reflux pipe 32 and a cooling pipe 33, and heat exchange can be performed between the reflux pipe 32 and the cooling pipe 33. The condensation reflux channel 31 is an internal channel of the reflux pipe 32, and a cooling medium is arranged in the cooling pipe 33. The lower end of the reflux pipe 32 is provided with an inlet 32a for connecting the condensation reflux channel 31 and the first channel 211, and the side end of the reflux pipe 32 is provided with an outlet 32b for connecting the condensation reflux channel 31 and the connecting channel 4; when bubbles enter the condensation reflux channel 31 through the inlet 32a, due to the heat exchange between the reflux pipe 32 and the cooling pipe 33, the cooling pipe 33 absorbs the heat in the reflux pipe 32, and the bubbles are cooled and liquefied into small droplets and are discharged from the side end of the reflux pipe 32 through the outlet 32b of the reflux pipe 32 to enter the connecting channel 4 for circulation.

[0041] In this embodiment, the cooling tube 33 is partially embedded in the return tube 32, and part of the outer wall of the cooling tube 33 forms the inner wall of the return tube 32. When the bubbles enter the return tube 32, they can directly contact the outer wall of the cooling tube 33, thereby greatly improving the heat exchange efficiency between the cooling medium and the bubbles in the cooling tube 33, with only the wall of the cooling tube 33 in between.

[0042] In this embodiment, the cooling medium in the cooling pipe 33 is one of air, water, refrigerant, and ethylene glycol aqueous solution. The cooling medium flows in the cooling pipe 33 to quickly take away the heat in the return pipe 32, thereby improving the cooling efficiency.

[0043] As an optional solution of the present invention, two baffles 321 are provided in the reflux pipe 32, and a vaporization channel 3211 is formed between the two baffles 321. The vaporization channel 3211 has a structure that is larger at the top and smaller at the bottom. The upper end of the vaporization channel 3211 is connected to the condensation reflux channel 31, and the lower end of the vaporization channel 3211 is connected to the inlet 32a. A liquefaction channel 3212 is formed between the baffle 321 and the inner wall of the reflux pipe 32, and the end of the liquefaction channel 3212 is connected to the connecting channel 4. The inner wall of the reflux pipe 32 is in an arc shape. When bubbles enter the condensation reflux through the inlet 32a and the vaporization channel 3211, After being cooled in the channel 31, small droplets are formed attached to the inner wall of the return pipe 32. Since the inner wall of the return pipe 32 is arc-shaped, the small droplets will slide downward along the inner wall of the return pipe 32. When the small droplets slide into the liquefaction channel 3212, they cannot fall from the vaporization channel 3211 due to the obstruction of the baffle 321. They can flow along the liquefaction channel 3212 to the two ends of the return pipe 32 and enter the return to the connecting channel 4 to realize circulation flow. The above-mentioned structural design can prevent the backflow of the low-boiling-point refrigerant during the circulation process, realize the orderly circulation of the low-boiling-point refrigerant in the box body 1, and improve the cooling effect on the battery pack 2.

[0044] As an optional solution of the present invention, the condensation module 3 also includes a reflux hood 34 arranged above the battery pack 2, and the reflux pipe 32 is installed in the reflux hood 34; the reflux hood 34 can play a good converging role for the bubbles floating above the battery pack 2, ensuring that the bubbles enter the reflux pipe 32 for cooling as much as possible, and avoiding a large amount of bubbles accumulating on the top of the box body 1 to cause safety accidents.

[0045] The present invention and its embodiments are described schematically above, and the description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by it and designs a structural method and an embodiment similar to the technical solution without creativity without departing from the purpose of the invention, they shall all fall within the protection scope of the present invention.

Claims

1. A lean liquid direct-cooled energy storage battery pack, characterized in that: include The box is filled with low boiling point refrigerant; The battery pack is immersed in the low-boiling-point refrigerant inside the box; A condensing module is disposed in the box and above the battery pack; The battery pack includes a plurality of first channel plates distributed at intervals and battery cells arranged between the first channel plates, a second channel plate is arranged at the bottom of the battery pack, a first channel in contact with the surface of the battery cell is arranged in the first channel plate, a second channel in contact with the surface of the battery cell is arranged in the second channel plate, a condensation reflux channel is arranged in the condensation module, at least one connecting channel for connecting the condensation reflux channel and the second channel is arranged between the battery pack and the box, and the condensation reflux channel, the connecting channel, the second channel and the first channel are connected to form a circulation loop; The first channel plate and the second channel plate are both porous structures, and the first channel and the second channel are pores inside the porous structure; The condensation module includes a reflux pipe and a cooling pipe, and heat exchange can be performed between the reflux pipe and the cooling pipe. The condensation reflux channel is an internal channel of the reflux pipe, and a cooling medium is arranged in the cooling pipe. The lower end of the reflux pipe is provided with an inlet for connecting the condensation reflux channel and the first channel, and the side end of the reflux pipe is provided with an outlet for connecting the condensation reflux channel and the connecting channel; Two baffles are arranged inside the reflux pipe, and a vaporization channel is provided between the two baffles. The upper end of the vaporization channel is connected with the condensation reflux channel, and the lower end of the vaporization channel is connected with the inlet. A liquefaction channel is provided between the baffle and the inner wall of the reflux pipe, and the end of the liquefaction channel is connected with the connecting channel. The inner wall of the reflux pipe is arc-shaped.

2. A lean liquid direct-cooled energy storage battery pack according to claim 1, characterized in that: The material of the first channel plate and the second channel plate is one of ceramic fiber, aerogel felt, glass fiber and asbestos cloth.

3. The lean liquid direct-cooled energy storage battery pack according to claim 1, characterized in that: The condensing module further comprises a reflux cover arranged above the battery pack, and the reflux pipe is installed in the reflux cover.

4. The lean liquid direct-cooling energy storage battery pack according to claim 1, characterized in that: The low boiling point refrigerant is one of organic substances such as halogenated alkanes, ketones, ethers or alkanes.

5. The lean liquid direct-cooling energy storage battery pack according to claim 1, characterized in that: The connecting channel is provided in each battery pack.

6. The lean liquid direct-cooled energy storage battery pack according to claim 1, characterized in that: The cooling medium is one of air, water, refrigerant, and ethylene glycol aqueous solution.

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