An immersion cooling system based on battery full-area heat dissipation

Abstract

The application discloses an immersion cooling system based on battery full-area heat dissipation, a sealed box module comprises a sealed box body, a battery module and a liquid cooling plate in the sealed box body, the battery module is inverted in the sealed box body, one side of the battery module provided with a tab can be immersed in the cooling liquid in the sealed box body, and the liquid cooling plate is located at the other side of the battery module; an outer circulation heat exchange module comprises a constant-temperature tank, an immersion cooling liquid circulation pipeline and a liquid cooling plate cooling liquid circulation pipeline, the constant-temperature tank is communicated with the sealed box body through the immersion cooling liquid circulation pipeline, and the constant-temperature tank is communicated with a cooling liquid flow channel of the liquid cooling plate through the liquid cooling plate cooling liquid circulation pipeline. The application adopts the structure that the battery is inverted in the cooling liquid to immerse the tab to cool the tab, the use amount of the cooling liquid can be reduced, and the cost is reduced. Meanwhile, a cold plate system is added above the system to balance the temperature uniformity under high-rate charging and discharging of the battery, the thermal gradient in the battery is reduced, and efficient full-area battery thermal management is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of integrated cooling, in particular to a liquid cooling cooling means suitable for a battery thermal management system, and more particularly to an immersion cooling system based on battery full-area heat dissipation. BACKGROUND

[0002] Lithium ion batteries are widely used in new energy vehicles due to their high specific energy, long cycle life, low self-discharge, and no memory effect, and are known as the "heart" of new energy vehicles. With the market's demand for higher energy density of lithium ion batteries for electric vehicles, traditional thermal management methods such as air cooling and pipeline liquid cooling cannot meet the requirements of battery heat dissipation. The emergence of super-fast charging mode makes the tab of the battery heat up particularly severely during high-rate charging and discharging. The rise in battery temperature will inevitably lead to a decrease in performance. Once the temperature exceeds the appropriate temperature, dendrites will be produced inside the battery, and even a short circuit will occur inside the battery, leading to thermal runaway, and ultimately causing a fire or explosion, endangering the safety of passengers.

[0003] The liquid cooling system, as the most commonly used battery thermal management method, can quickly remove the heat generated by the system. Chinese utility model patent CN 215496842U cools the battery module at the bottom and side of the battery, but ignores the tab cooling. Immersion cooling, as a new type of liquid cooling method, can enhance heat exchange efficiency and avoid complex pipeline design by directly immersing the lithium ion battery in the cooling liquid to reduce the contact thermal resistance between the two. It is an effective thermal management method. However, Chinese invention patent CN 114976382 A completely uses immersion cooling to manage the temperature of the battery, but requires a large amount of cooling liquid to immerse the battery module, which is too costly.

[0004] Therefore, there is a need for a low-cost immersion cooling system based on battery full-area uniform heat dissipation to efficiently cool the tab and improve the temperature uniformity of the battery module. SUMMARY

[0005] To solve the above problems, the present application provides a new low-cost lithium ion battery immersion cooling thermal management structure based on battery full-area uniform heat dissipation. By immersing the tab for heat dissipation, the internal temperature of the battery can be more uniform, the current distribution in the battery can be more uniform, and the cycle performance of the battery can be improved. Not only can it effectively cool the lithium battery tab under high-rate charging and discharging, improve the temperature uniformity of the battery, and reduce the internal temperature gradient of the battery pack, but also can reduce the amount of cooling liquid used and reduce costs.

[0006] To achieve the purpose of the present application, the present application provides an immersion cooling system based on battery full-area heat dissipation, comprising a sealed box module and an external circulation heat exchange module,

[0007] The sealed box module includes a sealed box body, a battery module and a liquid cooling plate located inside the sealed box body. The sealed box body is also used to contain coolant. The battery module is placed upside down inside the sealed box body, and the side of the battery module with the tabs can be immersed in the coolant. The liquid cooling plate is located on the other side of the battery module, and the liquid cooling plate is provided with coolant flow channels.

[0008] The external circulation heat exchange module includes a constant temperature bath, an immersion coolant circulation pipe, and a liquid cooling plate coolant circulation pipe. The constant temperature bath is connected to the sealed box through the immersion coolant circulation pipe to realize the circulation of the immersion coolant. The constant temperature bath is connected to the coolant flow channel of the liquid cooling plate through the liquid cooling plate coolant circulation pipe to realize the circulation of the coolant inside the liquid cooling plate.

[0009] More preferably, the battery module is suspended and fixed inside the sealed casing.

[0010] More preferably, it also includes a mounting rod and mounting rod fixing positions. Mounting rod fixing positions are provided on both opposite side walls of the sealed housing, and there is a distance between the mounting rod fixing positions and the bottom surface of the sealed housing. The two ends of the mounting rod are respectively fixed to the mounting rod fixing positions on both sides, and the battery module is fixed on the mounting rod.

[0011] More preferably, the liquid cooling plate includes a plate body and a groove formed in the plate body to form a coolant flow channel. The inlet of the coolant flow channel is located in the middle of the plate body, and the flow direction of the coolant flow channel is to both sides and then converges to the middle. The outlet of the coolant flow channel is also located in the middle of the plate body.

[0012] More preferably, the liquid cooling plate is fixedly connected to the top inner side of the sealed housing, and the liquid cooling plate is in contact with the top of the battery module.

[0013] More preferably, the immersion coolant circulation pipeline includes a first inlet pipeline and a first outlet pipeline. The sealed housing is provided with a first inlet and a first outlet. One end of the first inlet pipeline is connected to the constant temperature bath, and the other end is connected to the first inlet. One end of the first outlet pipeline is connected to the first outlet, and the other end is connected to the constant temperature bath.

[0014] More preferably, the first outlet is located at a higher position in the vertical direction than the first inlet.

[0015] More preferably, a first control valve is provided on the first inlet pipe, and a first circulation pump is provided on the first outlet pipe.

[0016] More preferably, the liquid cooling plate coolant circulation pipeline includes a second inlet pipeline and a second outlet pipeline. One end of the second inlet pipeline is connected to the constant temperature bath, and the other end is connected to the inlet end of the liquid cooling plate coolant flow channel. One end of the second outlet pipeline is connected to the outlet end of the liquid cooling plate coolant flow channel, and the other end is connected to the constant temperature bath.

[0017] More preferably, a second control valve is provided on the second inlet pipe, and a second circulation pump is provided on the second outlet pipe.

[0018] More preferably, the immersion coolant circulation and liquid plate coolant circulation are selected to be activated by a control valve. Under low-rate charge and discharge, either the immersion coolant circulation or the liquid plate coolant circulation is activated. Under high-rate charge and discharge, both the immersion coolant circulation and the liquid plate coolant circulation are activated simultaneously to achieve better battery module temperature control and lower energy efficiency control.

[0019] More preferably, the coolant is any one of the highly electrically insulating fluorides such as mineral oil, perfluoroamine, perfluoropolyether, or perfluorohexanone.

[0020] One advantage of this invention is that it discloses an immersion cooling system based on uniform heat dissipation across the entire battery area. Employing an inverted battery structure and a forced external circulation cooling system for localized immersion cooling, it enhances electrode tab heat dissipation, reduces electrode tab size and cost, and significantly reduces coolant consumption. Furthermore, a liquid cooling plate is added to the top of the system, and its activation during high-rate charge / discharge further improves the temperature uniformity of the battery pack.

[0021] Another advantage of this invention is that when the battery is inverted and immersed in the coolant, the released flammable gas can be cooled immediately in the event of thermal runaway, and any sparks that may be generated can be extinguished, further reducing the risk of battery combustion. Attached Figure Description

[0022] Figure 1 A schematic diagram of the overall structure of an immersion cooling system based on full-area heat dissipation of a battery, provided in an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the fixed cross-section of the battery module provided by the present invention;

[0024] Figure 3 This is a schematic diagram of the liquid cooling plate structure in an embodiment of the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention.

[0026] In the description of this invention, "several" means one or more, "more than" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0027] In the description of this invention, unless otherwise explicitly defined, terms such as setting, installing, connecting, and fixing should be interpreted broadly. Those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0028] Reference Figure 1 , Figure 2 and Figure 3 The present invention provides an immersion cooling device for full-area heat dissipation, comprising a sealed box module and an external circulation heat exchange module.

[0029] The sealed enclosure module includes a fully enclosed sealed enclosure 1, a battery module 3, a coolant 2, and a liquid cooling plate 5 fixed to the top of the battery module 3. The sealed enclosure 1 contains the coolant 2. The battery module 3 is suspended upside down inside the sealed enclosure 1 with its terminals submerged in the coolant 2. The liquid cooling plate 5 is located inside the sealed enclosure 1 and at the top of the battery module 3, and has coolant flow channels within it. The battery module 3 comprises multiple prismatic batteries assembled in series.

[0030] The external circulation heat exchange module includes a constant temperature tank 9, an immersion coolant circulation pipe, and a liquid-cooled plate coolant circulation pipe. The constant temperature tank 9 is connected to the sealed box 1 through the immersion coolant circulation pipe to realize the circulation of the immersion coolant 2. The constant temperature tank 9 is connected to the coolant flow channel of the liquid-cooled plate 5 through the liquid-cooled plate coolant circulation pipe to realize the circulation of the coolant in the liquid-cooled plate 5.

[0031] In this embodiment, the device also includes a mounting rod 6 and a mounting rod fixing position 4. The mounting rod fixing positions 4 are provided on both opposite side walls of the sealed housing 1, and a distance is left between the mounting rod fixing positions 4 and the bottom surface of the sealed housing 1 so that the battery module 3 can be suspended in the sealed housing 1. The two ends of the mounting rod 6 are respectively fixed on the mounting rod fixing positions 4 on both sides, and the bottom of the battery module 3 is fixed on the mounting rod 6.

[0032] In this embodiment, the immersion coolant circulation pipeline includes a first inlet pipeline and a first outlet pipeline. The constant temperature bath 9 is provided with a first outlet, a second outlet, a first inlet, and a second inlet. The sealed housing 1 is provided with a first inlet 22 and a first outlet 24. One end of the first inlet pipeline is connected to the first outlet of the constant temperature bath 9, and the other end is connected to the first inlet 22. One end of the first outlet pipeline is connected to the first outlet 24, and the other end is connected to the first inlet of the constant temperature bath 9. A first control valve 12 is provided on the first inlet pipeline, and a first circulation pump 8 is provided on the first outlet pipeline. The liquid cooling plate coolant circulation pipeline includes a second inlet pipeline and a second outlet pipeline. One end of the second inlet pipeline is connected to the second outlet of the constant temperature bath 9, and the other end passes through the second inlet 21 opened on the sealed housing 1 and is connected to the inlet end of the coolant flow channel of the liquid cooling plate 5. One end of the second outlet pipeline passes through the second outlet 23 opened on the sealed housing 1 and is connected to the outlet end of the coolant flow channel of the liquid cooling plate 5, and the other end is connected to the second inlet of the constant temperature bath 9. Furthermore, a second control valve 11 is installed on the second inlet pipe, and a second circulation pump 7 is installed on the second outlet pipe. The immersion coolant circulation pipe of the external circulation heat exchange module is connected to the sealed housing 1 through the first inlet 22 and the first outlet 24, enabling the coolant 2 within the sealed housing 1 to circulate. The liquid-cooled plate coolant circulation pipe is connected to the coolant flow channel and the constant temperature bath 9, enabling the coolant within the liquid-cooled plate 5 to circulate. The inlet flow rate and flow rate of the coolant can be controlled by setting the circulation pump, and the immersion coolant circulation and liquid-cooled plate coolant circulation can be selected by setting the control valve.

[0033] The external circulation heat exchange module includes the cooling circulation of the immersion liquid and the circulation of the liquid-cooled plate coolant, which are regulated by the second control valve 11 and the first control valve 12. Preferably, at low rates (i.e., charge / discharge rates below 2C, including 2C), the cooling circulation of the immersion liquid is activated to control the temperature rise and temperature uniformity of the battery module 3, ensuring temperature uniformity in the battery tab and non-tab areas. Maintaining the temperature consistency of individual cells within the battery module 3 under long-term circulation can effectively improve the battery module's lifespan. At high rates (i.e., charge / discharge rates above 3C, including 3C), the circulation of the immersion liquid and the circulation of the liquid-cooled plate coolant are activated simultaneously to achieve full-area heat dissipation of the battery module 3. The liquid-cooled plate 5 maintains the temperature above the battery module 3, while the immersion coolant acts on the area below the battery module 3 where heat is generated, simultaneously dissipating heat and achieving full-area temperature control of the battery. This achieves optimal temperature control and uniformity of the battery module 3 while reducing the amount of coolant used. More preferably, the constant temperature bath 9 in the external circulation heat exchange module can change the temperature of the coolant flowing into the circulation to optimize the temperature control capability of the system.

[0034] In this embodiment, the coolant 2 submerges the tabs of the battery module 3, and the level of the coolant 2 is always higher than the first outlet 24 to ensure effective circulation of the coolant.

[0035] In this embodiment, the first outlet 24 is located at a higher position in the vertical direction than the first inlet 22.

[0036] Coolant 2 is any one of the highly electrically insulating fluorides such as mineral oil, perfluoroamine, perfluoropolyether, or perfluorohexanone. In this embodiment, the coolant is perfluorohexanone.

[0037] Example 2

[0038] This embodiment provides an immersion cooling device for full-area heat dissipation, including a sealed box module and an external circulation heat exchange module.

[0039] The sealed enclosure module includes a fully enclosed sealed enclosure 1, a battery module 3, a coolant 2, and a liquid cooling plate 5 fixed to the top of the battery module 3. The sealed enclosure 1 contains the coolant 2. The battery module 3 is suspended upside down inside the sealed enclosure 1 with its terminals submerged in the coolant 2. The liquid cooling plate 5 is located inside the sealed enclosure 1 and at the top of the battery module 3, and has coolant flow channels within it. The battery module 3 comprises multiple prismatic batteries assembled in series.

[0040] The external circulation heat exchange module includes a constant temperature tank 9, an immersion coolant circulation pipe, and a liquid-cooled plate coolant circulation pipe. The constant temperature tank 9 is connected to the sealed box 1 through the immersion coolant circulation pipe to realize the circulation of the immersion coolant 2. The constant temperature tank 9 is connected to the coolant flow channel of the liquid-cooled plate 5 through the liquid-cooled plate coolant circulation pipe to realize the circulation of the coolant in the liquid-cooled plate 5.

[0041] In this embodiment, the mounting rod 6 is a screw rod, and the mounting rod fixing position 4 is provided with an internal thread. The mounting rod 6 and the mounting rod fixing position 4 are threadedly connected to achieve fixation between them.

[0042] In this embodiment, the liquid cooling plate 5 is located above the battery module 3, closely abutting the upper wall of the battery module 3 and the sealed housing 1. Preferably, the liquid cooling plate 5 and the upper wall of the sealed housing 1 are threadedly fixedly connected.

[0043] Example 3

[0044] This embodiment provides an immersion cooling device for full-area heat dissipation, including a sealed box module and an external circulation heat exchange module.

[0045] The sealed enclosure module includes a fully enclosed sealed enclosure 1, a battery module 3, a coolant 2, and a liquid cooling plate 5 fixed to the top of the battery module 3. The sealed enclosure 1 contains the coolant 2. The battery module 3 is suspended upside down inside the sealed enclosure 1 with its terminals submerged in the coolant 2. The liquid cooling plate 5 is located inside the sealed enclosure 1 and at the top of the battery module 3, and has coolant flow channels within it. The battery module 3 comprises multiple prismatic batteries assembled in series.

[0046] The external circulation heat exchange module includes a constant temperature tank 9, an immersion coolant circulation pipe, and a liquid-cooled plate coolant circulation pipe. The constant temperature tank 9 is connected to the sealed box 1 through the immersion coolant circulation pipe to realize the circulation of the immersion coolant 2. The constant temperature tank 9 is connected to the coolant flow channel of the liquid-cooled plate 5 through the liquid-cooled plate coolant circulation pipe to realize the circulation of the coolant in the liquid-cooled plate 5.

[0047] In this embodiment, please refer to Figure 3 The liquid cooling plate 5 includes a plate body and recesses formed in the plate body to create coolant channels. The inlet of the coolant channels is located in the middle of the plate body, and the coolant flows to both sides before converging back to the middle. The outlet of the coolant channels is also located in the middle of the plate body. The arrows in the figure represent the flow direction of the fluid inside the liquid cooling plate 5. During operation, the battery temperature in the middle of the battery module 3 is often higher than that of the batteries at both ends. By placing the inlet and outlet of the coolant channels in the middle of the plate body, the liquid cooling plate 5 can effectively reduce the temperature of the battery in the middle of the battery module, improving the overall temperature uniformity of the battery module.

[0048] The aforementioned embodiments of the invention provide an immersion cooling system based on full-area battery heat dissipation. By employing a structure where the battery is inverted and submerged in coolant to cool the tabs, the amount of coolant used can be reduced, thus lowering costs. Furthermore, the coolant can also immediately extinguish any flames released during battery thermal runaway. Simultaneously, a liquid cooling plate is added above the system to balance the temperature uniformity of the battery under high-rate charging and discharging, reducing the internal thermal gradient of the battery and achieving efficient full-area battery thermal management.

[0049] The above detailed description is a specific description of feasible embodiments of the present invention. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. All equivalent implementations or modifications that do not depart from the present invention should be included in the patent protection scope of this case.

Claims

1. An immersion cooling system device based on full-area heat dissipation of a battery, characterized in that, Includes a sealed box module and an external circulation heat exchange module. The sealed box module includes a sealed box body (1) and a battery module (3) and a liquid cooling plate (5) located inside the sealed box body (1). The sealed box body (1) is also used to contain coolant (2). The battery module (3) is placed upside down and suspended in the sealed box body (1). The side of the battery module (3) with tabs can be immersed in the coolant (2). The liquid cooling plate (5) is located on the other side of the battery module (3). The liquid cooling plate (5) is provided with coolant flow channels. The external circulation heat exchange module includes a constant temperature tank (9), an immersion coolant circulation pipe and a liquid cooling plate coolant circulation pipe. The constant temperature tank (9) is connected to the sealed box (1) through the immersion coolant circulation pipe to realize the circulation of the immersion coolant (2). The constant temperature tank (9) is connected to the coolant flow channel of the liquid cooling plate (5) through the liquid cooling plate coolant circulation pipe to realize the circulation of the coolant in the liquid cooling plate (5). At low charge / discharge rates, either immersion coolant circulation or liquid plate coolant circulation can be activated. At high charge / discharge rates, both immersion coolant circulation and liquid plate coolant circulation can be activated simultaneously.

2. The immersion cooling system device based on full-area heat dissipation of the battery according to claim 1, characterized in that, The liquid cooling plate (5) includes a plate body and a groove formed in the plate body to form a coolant flow channel. The inlet of the coolant flow channel is located in the middle of the plate body, and the flow direction of the coolant flow channel is to both sides and then converges to the middle. The outlet of the coolant flow channel is also located in the middle of the plate body.

3. The immersion cooling system device based on full-area heat dissipation of the battery according to claim 1, characterized in that, The liquid cooling plate (5) is fixedly connected to the top inner side of the sealed box (1), and the liquid cooling plate (5) is in contact with the top of the battery module (3).

4. The immersion cooling system device based on full-area heat dissipation of the battery according to claim 1, characterized in that, The immersion coolant circulation pipeline includes a first inlet pipe and a first outlet pipe. The sealed box (1) is provided with a first inlet (22) and a first outlet (24). One end of the first inlet pipe is connected to the constant temperature bath (9), and the other end is connected to the first inlet (22). One end of the first outlet pipe is connected to the first outlet (24), and the other end is connected to the constant temperature bath (9).

5. The immersion cooling system device based on full-area heat dissipation of the battery according to claim 4, characterized in that, The first exit (24) is located higher in the vertical direction than the first inlet (22).

6. The immersion cooling system device based on full-area heat dissipation of the battery according to claim 4, characterized in that, A first control valve (12) is installed on the first inlet pipe, and a first circulation pump (8) is installed on the first outlet pipe.

7. The immersion cooling system device based on full-area heat dissipation of a battery according to claim 1, characterized in that, The liquid cooling plate cooling fluid circulation pipeline includes a second inlet pipe and a second outlet pipe. One end of the second inlet pipe is connected to the constant temperature bath (9), and the other end is connected to the inlet end of the coolant flow channel of the liquid cooling plate (5). One end of the second outlet pipe is connected to the outlet end of the coolant flow channel of the liquid cooling plate (5), and the other end is connected to the constant temperature bath (9).

8. The immersion cooling system device based on full-area heat dissipation of the battery according to claim 7, characterized in that, A second control valve (11) is installed on the second inlet pipe, and a second circulation pump (7) is installed on the second outlet pipe.

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