Liquid cooling device for battery heat dissipation and design method thereof and battery

Abstract

The application discloses a liquid cooling device for battery heat dissipation, a design method thereof and a battery, and the liquid cooling device comprises a shell, a first liquid cooling layer and a second liquid cooling layer; the first liquid cooling layer comprises a first bionic topological flow guiding unit and first and second bionic spider web liquid cooling units; the first and second bionic spider web liquid cooling units are of the same structure and comprise a first center frame and a first bionic spider web flow channel; the first liquid cooling layer and the second liquid cooling layer are separated by a heat insulation plate, and the liquid flow channel of the second liquid cooling layer completely covers the non-liquid flow channel area of the first liquid cooling layer except the first center frame. The application adopts the cooperative design of the integrated double-layer staggered channel and the bionic spider web shunt topology, realizes the dead angle-free heat exchange at the bottom of the battery cell through the complementary of the upper and lower flow channels, accurately controls the maximum temperature of the battery pack and the temperature difference of the whole battery pack, has compact and reasonable structure, high overall heat dissipation efficiency, excellent temperature equalization performance, low fluid flow resistance and wide battery cell adaptation range.

Description

Technical Field

[0001] This invention belongs to the field of battery thermal management technology, specifically relating to a liquid cooling device for battery heat dissipation, its design method, and the battery. Background Technology

[0002] With the rapid development of new energy vehicles, large-scale energy storage, and other fields, the application scenarios of lithium-ion batteries are constantly expanding, and the requirements for their power density and energy density are also continuously increasing. Under high-rate discharge conditions, lithium-ion batteries will rapidly generate a large amount of heat. If the heat cannot be dissipated in time, the internal temperature of the battery pack will rise sharply, which will not only reduce the battery's charge and discharge efficiency and cycle life, but may also cause thermal runaway, seriously threatening the operational safety of the equipment.

[0003] Existing liquid cooling devices mostly adopt traditional single-layer flow channel structures such as straight channels and serpentine channels, which have problems such as limited heat exchange area, poor temperature uniformity, and large flow resistance. For example, straight channel liquid cooling devices are prone to forming hot spots at the end of the channel, resulting in excessive temperature differences inside the battery pack; although serpentine channels can improve heat exchange uniformity, the large number of bends in the structure increases the flow resistance, consumes more pumping power, and reduces the overall energy efficiency of the system.

[0004] To address the issue of large-area heat accumulation in power battery cells, existing publicly available technologies have proposed several solutions. For example, patent application CN118173946A discloses a biomimetic leaf vein-inspired corrugated channel liquid cooling plate, comprising two interconnected plate bodies. The second plate body has a central inlet main channel and two side outlet main channels communicating with the inlet main channel at its edges. The upstream of the inlet main channel is the main working fluid inlet, and the downstream is the downstream end of the working fluid inlet channel. From the main working fluid inlet to the downstream end of the working fluid inlet channel, the inlet main channel has a gradually narrowing structure. This invention is a liquid cooling plate based on the overall structural design of the biomimetic leaf vein-inspired inlet main channel, outlet main channel, and corrugated branch channels, which improves heat exchange capacity, significantly enhances the temperature uniformity of the power battery, and achieves lower energy consumption. For example, the invention patent with announcement number CN120237335B discloses a power battery liquid cooling heat dissipation device with a biomimetic shark skin flow channel structure. It includes a cover plate, a base, and coolant flow channels disposed on the base. The cover plate and the base are connected to form a liquid cooling plate, and the coolant flow channels are grooves formed on the base. Shark skin is covered with scutes, each scute being rhomboid in shape, with grooves and ribs distributed on its outer surface. In this device, the oblique flow channels divide the coolant flow channels into several rhomboid flow channels—single rhomboid regions. The rhomboid flow channels are biomimetic to the rhomboid shape of shark scutes. Several straight channels penetrate the rhomboid flow channels, mimicking the groove structure of the scutes. The parts not penetrated by the straight channels mimic the ribs of the scutes. The ribs and grooves are staggered, making the coolant flow channels resemble the scutes of shark skin. This effectively reduces water flow resistance, improves fluid flow efficiency, and thus enhances heat dissipation performance.

[0005] However, the following problems are common in existing technologies:

[0006] (1) Conventional single-layer flow channel cold plate heat exchange coverage area is single, and there are a large number of solid blind areas without flow channels on the plate surface. It is difficult to dissipate local heat at the bottom of the cell, which is difficult to adapt to the heat dissipation requirements of large-area active groups and large-capacity long strip battery modules. It cannot simultaneously achieve high uniform temperature heat dissipation, low flow resistance loss and high space utilization.

[0007] (2) The flow channel structure is unreasonable, the temperature uniformity is extremely poor and the risk of local hot spots is high; the mainstream straight channel liquid cooling plate adopts a parallel rectangular flow channel (common cross-sectional size 2mm×5mm). The coolant continuously absorbs heat and rises in temperature along the path from the inlet to the outlet, resulting in the temperature of the battery area at the outlet end of the flow channel being 12~18℃ higher than that at the inlet end, forming an obvious "inlet-outlet temperature gradient"; at the same time, the straight channel can only cover a local area of ​​the battery module, which is easy to form a heat dissipation blind zone, and the hot spot temperature can reach 45~55℃, far exceeding the ideal working temperature of lithium-ion batteries below 35℃;

[0008] (3) A single-layer cold plate can only exchange heat with the battery through a single plane flow channel. The effective heat exchange area is strictly limited by the size of the cold plate, usually only 45%~55% of that of a double-layer cold plate of the same size. Interlayer thermal crosstalk is likely to occur between the upper and lower modules, which further affects the overall heat exchange efficiency. In addition, in order to ensure the heat dissipation effect, a single-layer cold plate needs to reserve sufficient installation space on one side of the battery module, and the flow channel layout is fixed, which cannot adapt to the heat dissipation requirements of multi-layer stacked battery modules. Especially in large modules and highly integrated battery packs, the single channel layout is prone to heat dissipation blind spots, or due to structural redundancy, too much battery installation space is occupied, which restricts the improvement of battery pack energy density.

[0009] (4) It is difficult to balance heat dissipation efficiency and flow resistance. In order to improve heat dissipation capacity, existing solutions often expand the heat exchange area by reducing the flow channel cross section and increasing the flow channel length. However, this will significantly increase the fluid friction resistance and local resistance, resulting in a surge in pumping power consumption, which violates the core requirements of energy saving and consumption reduction of new energy equipment.

[0010] (5) The liquid cooling device design method lacks adaptability and cannot be designed for different models of battery modules. It only changes the liquid cooling device by simply enlarging the size, resulting in significant differences in heat dissipation effect between different models of battery modules. Summary of the Invention

[0011] The purpose of this invention is to overcome the shortcomings of the prior art and provide a liquid cooling device for battery heat dissipation, its design method, and the battery itself. It adopts a collaborative design of an integrated double-layer staggered channel and a biomimetic spider web topology. Through the staggered and complementary flow channels of the upper and lower layers, heat exchange at the bottom of the battery cell is achieved without dead angles. It can accurately control the maximum temperature of the battery pack and the temperature difference of the entire pack. The structure is compact and reasonable, with high heat dissipation efficiency, excellent temperature uniformity, low fluid flow resistance, and a wide range of cell compatibility, including lithium-ion batteries that are suitable for ultra-high rate discharge conditions.

[0012] This invention provides the following technical solution:

[0013] In a first aspect, a liquid cooling device for battery heat dissipation is provided, including a housing and a first liquid cooling layer and a second liquid cooling layer disposed within the housing;

[0014] The first liquid cooling layer includes a first biomimetic topology flow guiding unit and a first biomimetic spider web liquid cooling unit and a second biomimetic spider web liquid cooling unit connected to both sides of the first biomimetic topology flow guiding unit; the first biomimetic spider web liquid cooling unit and the second biomimetic spider web liquid cooling unit have the same structure, including a first central frame and a first biomimetic spider web flow channel disposed around the first central frame.

[0015] The second liquid cooling layer includes a second biomimetic topology flow guiding unit and a third biomimetic spider web liquid cooling unit and a fourth biomimetic spider web liquid cooling unit disposed on both sides of the second biomimetic topology flow guiding unit;

[0016] The first liquid cooling layer and the second liquid cooling layer are separated by a heat insulation plate, and the liquid flow channel of the second liquid cooling layer completely covers the non-liquid flow channel area of ​​the first liquid cooling layer except for the first central frame.

[0017] Furthermore, the first biomimetic spider web flow channel includes a first main flow channel and a first primary flow channel. The first main flow channel is symmetrically distributed on both sides of the first central frame and extends radially. Between the first main flow channels on both sides of the first central frame, there are multiple first primary flow channels in a spider web shape that are symmetrically distributed relative to the first central frame.

[0018] Furthermore, the width of the first main channel gradually increases from the first central frame outwards, and the angle between the first main channel and the first flow channel is 85°~110°.

[0019] Furthermore, the first biomimetic topology flow guiding unit includes a main flow guiding channel and an inlet flow channel and an outlet flow channel respectively disposed on both sides of the main flow guiding channel. The inlet flow channel is connected to the first flow channel of the first biomimetic spider web liquid cooling unit, and the outlet flow channel is connected to the first flow channel of the second biomimetic spider web liquid cooling unit.

[0020] The angle between the inlet channel and the first channel of the first biomimetic spider web liquid cooling unit is 75°~90°.

[0021] The angle between the outlet channel and the first channel of the second biomimetic spider web liquid cooling unit is 95°~110°.

[0022] Furthermore, the third and fourth biomimetic spider web liquid cooling units have the same structure, including a second central frame and a second biomimetic spider web flow channel disposed around the second central frame;

[0023] The second biomimetic spider web flow channel includes a second main flow channel and a second flow channel. The second main flow channel is symmetrically distributed on both sides of the second central frame and extends radially. Between the second main flow channels on both sides of the second central frame, there are multiple second flow channels in a spider web pattern that are symmetrically distributed relative to the second central frame.

[0024] The second main channel covers the first main channel, and the second channel is staggered with the first channel, so that the second channel covers the non-first channel areas on both sides of the first main channel;

[0025] And / or, the second biomimetic topology flow guiding unit includes a flow guiding plate disposed corresponding to the main flow guiding channel, so that flow guiding channels are formed on both sides of the flow guiding plate.

[0026] Furthermore, the two ends of the shell are respectively provided with a main water inlet and a main water outlet. The first bionic spider web liquid cooling unit and the third bionic spider web liquid cooling unit are respectively provided with a first water inlet branch and a second water inlet branch connected to the main water inlet. The second bionic spider web liquid cooling unit and the fourth bionic spider web liquid cooling unit are respectively provided with a first water outlet branch and a second water outlet branch connected to the main water outlet.

[0027] And / or, the thickness of the first liquid cooling layer and the second liquid cooling layer is 2.8~3.2mm, and the thickness of the heat insulation plate is 1.8~2.2mm.

[0028] In a second aspect, a design method for the liquid cooling device for battery heat dissipation described in the first aspect is provided, comprising:

[0029] Obtain the dimensions of the battery module, the continuous discharge rate, and the maximum allowable installation thickness of the liquid cooling device;

[0030] Determine heat dissipation conditions based on continuous discharge rate;

[0031] Based on the heat dissipation conditions and the size of the battery module, the flow channel parameters of the first biomimetic spider web liquid cooling unit and the second biomimetic spider web liquid cooling unit in the first liquid cooling layer, as well as the flow channel parameters of the first biomimetic topology guiding unit, are determined to obtain the first liquid cooling layer.

[0032] Based on the first liquid cooling layer, a second liquid cooling layer is obtained by using differentiated topology parameters, so that the liquid flow channels of the second liquid cooling layer completely cover the non-liquid flow channel area of ​​the first liquid cooling layer except for the first central frame.

[0033] The thicknesses of the first liquid cooling layer, the second liquid cooling layer, and the insulation plate are determined based on the maximum allowable installation thickness of the liquid cooling device, thus obtaining the liquid cooling device.

[0034] Furthermore, the determination of heat dissipation conditions based on the continuous discharge rate includes:

[0035] If the continuous discharge rate C rate If the temperature is ≤2C, it is considered a low-speed energy storage condition. The core design constraints are low flow resistance and reduced pumping energy consumption.

[0036] If 2C < C rate ≤3C indicates the medium-rate operating condition of in-vehicle fast charging, and the core design constraint is the balance between temperature uniformity and flow resistance;

[0037] If 3C < C rate ≤5C indicates a high-rate, high-power operating condition, and the core design constraints are to enhance local convection and reduce the overall temperature difference of the package.

[0038] Furthermore, determining the flow channel parameters of the first biomimetic spiderweb liquid cooling unit and the second biomimetic spiderweb liquid cooling unit, as well as the flow channel parameters of the first biomimetic topology guiding unit in the first liquid cooling layer, based on the heat dissipation conditions and the size of the battery module, includes:

[0039] The positions of the first center frames of the first and second biomimetic spider web liquid cooling units are determined based on the size of the battery module.

[0040] The width of the first main channel inlet D1, the width of the first flow channel D2, and the flow channel size D3 of the first biomimetic topological flow guiding unit are determined according to the heat dissipation conditions: If it is a low-speed energy storage condition, then D1∈[3.5,4.0] mm, D2∈[12,15] mm, D3= D2; if it is a medium-rate vehicle fast charging condition, then D1∈[3.0,3.5] mm, D2∈[10,12] mm, D3= D2; if it is a high-rate high-power condition, then D1∈[2.5,3.0] mm, D2∈[7,10] mm, D3= D2.

[0041] The number of first flow channels n1 is determined based on the size of the battery module and the width D2 of the first flow channel.

[0042] Thirdly, a battery is provided, including a battery case, a plurality of battery modules disposed within the battery case, and a liquid cooling device for heat dissipation as described in the first aspect disposed between the battery modules.

[0043] Furthermore, the contact surface between the module and the biomimetic spider web double-layer composite liquid cooling device is coated with a thermally conductive material or equipped with a thermally conductive pad.

[0044] Compared with the prior art, the beneficial effects of the present invention are:

[0045] (1) The liquid cooling device provided by the present invention includes a first liquid cooling layer and a second liquid cooling layer. The liquid flow channel of the second liquid cooling layer completely covers the non-liquid flow channel area of ​​the first liquid cooling layer except for the first central frame. Through the innovative double-layer differentiated staggered flow channel structure, it breaks through the design limitations of traditional straight channel, serpentine channel and single-layer bionic spider web flow channel. It utilizes the complementary coverage of the upper and lower flow channels to eliminate the heat exchange blind zone and local hot spot of the battery module, significantly improving the temperature uniformity of the entire battery pack under high-rate discharge conditions. Under the continuous discharge conditions of 3C~5C high-rate, the maximum temperature difference of the entire pack can be controlled within 3.5~5℃, thus avoiding the risk of inconsistent cell aging and thermal runaway caused by local overheating from the root.

[0046] (2) The liquid cooling device provided by the present invention adopts a double-layer liquid cooling layer staggered flow channel design, which can simultaneously dissipate heat on the upper and lower battery modules. Under the same external size, the effective heat exchange area is increased by 80%~100% compared with the traditional single-layer cold plate. There is no need to add multiple layers of heat dissipation plates. It makes full use of the limited installation space at the bottom of the battery pack, reduces the volume occupied by the thermal management system, and leaves more space for cell arrangement, which helps to improve the energy density of the battery pack. At the same time, it can effectively reduce the medium flow velocity and pressure loss along the flow path in the single-layer flow channel. Compared with the conventional serpentine cold plate, the overall flow resistance is significantly reduced, reducing the power consumption of the cooling water pump and improving the overall energy efficiency of the vehicle and energy storage system.

[0047] (3) In the liquid cooling device provided by the present invention, the first liquid cooling layer and the second liquid cooling layer are separated by a heat insulation plate. On the one hand, it can realize the compact arrangement of the double liquid cooling layer, so that the overall thickness of the liquid cooling device is controlled within 12mm and the thickness of the liquid cooling layer accounts for more than 50% of the total thickness of the liquid cooling device, which significantly improves the heat dissipation efficiency. On the other hand, the presence of the heat insulation plate can suppress the interlayer thermal crosstalk between the upper and lower battery modules, enhance the overall heat exchange efficiency and heat dissipation stability under complex working conditions, and is especially suitable for heat dissipation of long strips or large areas of positive groups.

[0048] (4) In the liquid cooling device provided by the present invention, the first liquid cooling layer includes a first biomimetic spider web liquid cooling unit and a second biomimetic spider web liquid cooling unit and a first biomimetic topology flow guiding unit connecting the two. Further, the first biomimetic spider web liquid cooling unit includes a first central frame, a first main channel and a first flow channel, forming a spider web-like topology structure of "central node + radial main channel + radial secondary channel + flow guiding branch". It has high heat dissipation efficiency and low flow resistance, so that the coolant can be evenly distributed in the flow channel and has good temperature uniformity. It completely breaks the temperature gradient dilemma of "cold inlet and hot outlet" in traditional straight channels, and can effectively eliminate heat dissipation blind spots such as the edge and corner of the battery module, and meet the heat dissipation requirements of the battery module.

[0049] (5) The design method of the liquid cooling device provided by the present invention fully considers the size of the battery module, the continuous discharge rate and the maximum allowable installation thickness of the liquid cooling device. It adaptively adjusts the center frame position, main channel width and secondary branch density for battery modules of different sizes and models, thereby improving the adaptability of the liquid cooling device to batteries of different shapes such as square, cylindrical and soft pack, large area positive groups and compact high integration battery packs. Under the premise of ensuring the overall heat dissipation effect, the overall thickness of the cold plate and the installation space are compressed, which helps to improve the energy density of the battery pack system. In addition, the upper and lower flow channels are independent of each other. They can be introduced with the same cooling medium for synchronous heat exchange, or different heat exchange media can be introduced according to the working conditions. The structural modification is small. It can be mass-produced by CNC milling and brazing, or complex interlaced flow channels can be formed by metal 3D printing. It can be adapted to various application scenarios such as passenger car power batteries, engineering machinery power supplies and large energy storage power station modules. The technology derivative and engineering implementation value is higher.

[0050] (6) The liquid cooling device and its design method provided by the present invention deeply integrate the biomimetic spider web shunt structure and the double-layer staggered complementary channel layout, give full play to the potential of the two to synergistic heat exchange and efficiency enhancement, make up for the inherent shortcomings of the single-layer flow channel heat exchange coverage, and enhance the heat dissipation stability under the complex working conditions of high-power continuous discharge; greatly improve the temperature control adaptability of the liquid cooling device to the 3C~5C high-rate charge and discharge working conditions, quickly export the concentrated heat generated by the cell, and stably control the highest temperature and the maximum temperature difference of the battery within the safe threshold range, avoid the safety risk of thermal runaway caused by local overheating from the source, enhance the engineering application value of the device, provide a reliable thermal management solution for scenarios such as new energy vehicle power battery packs and large-capacity battery modules of energy storage power stations, and promote the safe application of lithium-ion batteries in the fields of high power and high integration. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the liquid cooling device in an embodiment of the present invention;

[0052] Figure 2 This is a schematic diagram of the structure of the first liquid cooling layer in an embodiment of the present invention;

[0053] Figure 3 This is a schematic diagram of the structure of the second liquid cooling layer in an embodiment of the present invention;

[0054] Figure 4 This is a schematic diagram of the structure of the first biomimetic topology flow guiding unit in an embodiment of the present invention;

[0055] Figure 5 This is another structural schematic diagram of the first liquid cooling layer in an embodiment of the present invention;

[0056] Figure 6 This is a side sectional view of the liquid cooling device in an embodiment of the present invention;

[0057] Figure 7 This is a schematic diagram of the fluid flow direction in the liquid cooling device in an embodiment of the present invention;

[0058] Figure 8 This is a schematic diagram of the fluid flow direction within the first liquid cooling layer in an embodiment of the present invention;

[0059] Figure 9 This is a schematic diagram of the fluid flow direction within the second liquid cooling layer in an embodiment of the present invention;

[0060] Figure 10 This is a schematic diagram of the installation structure of the liquid cooling device in Embodiment 3 of the present invention;

[0061] Figure 11 This is a schematic diagram of the internal structure of the battery in Embodiment 3 of the present invention;

[0062] Figure 12 These are cell temperature cloud diagrams of the three liquid cooling devices in Embodiment 4 of the present invention: (a) is the cell temperature cloud diagram of a single-layer flow channel cold plate, (b) is the cell temperature cloud diagram of a double-layer isomorphic channel cold plate, and (c) is the cell temperature cloud diagram of the double-layer staggered channel liquid cooling device of the present invention.

[0063] Figure 13 This is a comparison chart of the highest temperatures of the three liquid cooling devices in Embodiment 4 of the present invention;

[0064] Figure 14 This is a comparison diagram of the cell temperature difference of the three liquid cooling devices in Embodiment 4 of the present invention.

[0065] The diagram is labeled as follows: 1. Shell; 2. Main inlet; 3. Main outlet; 4. First liquid cooling layer; 5. Second liquid cooling layer; 6. First biomimetic spider web liquid cooling unit; 61. First main channel; 62. First flow channel; 63. First center frame; 7. Second biomimetic spider web liquid cooling unit; 8. First biomimetic topology guiding unit; 81. Flow guiding main channel; 82. Inlet channel; 83. Outlet channel; 9. First inlet branch; 10. First outlet branch; 11. First module; 12. Second module; 13. Liquid cooling device; 14. Heat insulation plate; 15. Third biomimetic spider web liquid cooling unit; 151. Second main channel; 152. Second flow channel; 153. Second center frame; 16. Fourth biomimetic spider web liquid cooling unit; 17. Second biomimetic topology guiding unit; 18. Second inlet branch; 19. Second outlet branch. Detailed Implementation

[0066] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0067] It should be noted that in the description of this invention, the terms "front", "rear", "left", "right", "upper", "lower", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and do not require that this invention must be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0068] In the description of this invention, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0069] Example 1

[0070] like Figures 1-6 As shown, this embodiment provides a liquid cooling device for battery heat dissipation, including a housing 1, a first liquid cooling layer 4, a second liquid cooling layer 5, and a heat insulation plate 14. The first liquid cooling layer 4 and the second liquid cooling layer 5 are separated by the heat insulation plate 14 and disposed within the housing 1. The first liquid cooling layer 4 includes a first biomimetic topology flow guiding unit 8 and a first biomimetic spider web liquid cooling unit 6 and a second biomimetic spider web liquid cooling unit 7 connected to both sides of the first biomimetic topology flow guiding unit 8. The first biomimetic spider web liquid cooling unit 6 and the second biomimetic spider web liquid cooling unit 7 have the same structure, including a first central frame 63 and a first biomimetic spider web flow channel disposed around the first central frame 63. The second liquid cooling layer 5 includes a second biomimetic topology flow guiding unit 17 and a third biomimetic spider web liquid cooling unit 15 and a fourth biomimetic spider web liquid cooling unit 16 disposed on both sides of the second biomimetic topology flow guiding unit 17. The liquid flow channel of the second liquid cooling layer 5 completely covers the non-liquid flow channel area of ​​the first liquid cooling layer 4 except for the first central frame 63.

[0071] like Figures 1-3 As shown, the shell 1 has a main water inlet 2 and a main water outlet 3 at its two ends, respectively. The first biomimetic spider web liquid cooling unit 6 and the third biomimetic spider web liquid cooling unit 15 are respectively provided with a first water inlet branch 9 and a second water inlet branch 18 connected to the main water inlet 2. The second biomimetic spider web liquid cooling unit 7 and the fourth biomimetic spider web liquid cooling unit 16 are respectively provided with a first water outlet branch 10 and a second water outlet branch 19 connected to the main water outlet 3, thereby forming two independent flow channels at the top and bottom. Figure 7As shown, the cooling medium is introduced from the main water inlet 2 of the housing 1, and then flows into the first liquid cooling layer 4 and the second liquid cooling layer 5 through the first water inlet 9 of the first liquid cooling layer 4 and the second water inlet 18 of the second liquid cooling layer 5, respectively, to dissipate heat from the upper and lower battery modules. Then, it flows out through the first water outlet 10 and the second water outlet 19 of the two liquid cooling layers, respectively, to the main water outlet 3 of the housing 1. This can effectively avoid local hot spots and further equalize the temperature field.

[0072] like Figure 2 , Figure 8 and Figure 9 As shown, the first biomimetic spiderweb flow channel includes a first main flow channel 61 and a first secondary flow channel 62. The first main flow channel 61 is symmetrically distributed on both sides of the first central frame 63 and extends radially. Between the first main flow channels 61 on both sides of the first central frame 63, there is a spiderweb-shaped first secondary flow channel 62 symmetrically distributed relative to the first central frame 63. This forms a spiderweb-like topology of "central node + radial main flow channel + radial secondary flow channel". The cooling medium enters the first main flow channel 61 from the first water inlet branch 9 and then flows radially along the first secondary flow channel 62, which greatly improves the heat exchange area and temperature uniformity, while reducing the flow resistance. Compared with the traditional straight channel, the temperature difference can be reduced by 20% to 25%.

[0073] like Figure 2 and Figure 5 As shown, the width of the first main channel 61 gradually increases outward from the first central frame 63. The angle γ at the junction of the first flow channel 62 and the first main channel 61 is 85°~110°, and the angle δ between the centerline of the first flow channel 62 and the centerline of the first main channel 61 is 87°~113°. This design of the first flow channel 62 allows the cooling medium to flow into the first flow channel 62 / first main channel 61 at a gentle angle, effectively reducing local resistance and pressure loss in the confluence area, weakening the impact of the fluid on the inner wall of the channel and suppressing cavitation. Compared with the honeycomb structure, the pressure drop can be reduced by more than 60%, reducing water pump power consumption and improving endurance. In addition, this angle can ensure flow stability, avoid backflow and strong turbulence, achieve uniform flow distribution in the biomimetic spider web secondary flow channel, improve the uniformity of the battery temperature field, and reduce the difficulty of processing and molding.

[0074] In some specific embodiments, the angle γ at the junction of the first flow channel 62 and the first main flow channel 61 can be set to 98°, and the angle δ between the center lines of the first flow channel 62 and the first main flow channel 61 can be set to 100°. This angle can minimize the flow resistance and achieve the best temperature field uniformity.

[0075] like Figure 2 and Figure 4As shown, the first biomimetic topology flow guiding unit 8 includes a main flow guiding channel 81 and an inlet flow channel 82 and an outlet flow channel 83 respectively disposed on both sides of the main flow guiding channel 81. The inlet flow channel 82 is connected to the first flow channel 62 of the first biomimetic spider web liquid cooling unit 6, and the outlet flow channel 83 is connected to the first flow channel of the second biomimetic spider web liquid cooling unit 7. The angle α between the inlet flow channel 82 and the first flow channel 62 of the first biomimetic spider web liquid cooling unit 6 is 75°~90°. The near-right angle design allows the cooling medium to flow smoothly into the main flow guiding channel 81, effectively reducing local flow resistance and pressure loss in the inlet area, suppressing eddies and reverse backflow, ensuring the unidirectional flow guiding function of the structure, and reducing the impact and wear resistance of the fluid on the inner wall of the channel. The angle β between the outlet flow channel 83 and the first flow channel of the second biomimetic spider web liquid cooling unit 7 is 95°~110°. This slightly obtuse angle design enables directional jetting of the cooling medium, precisely connecting to the first flow channel of the second biomimetic spider web liquid cooling unit 7, optimizing the jet diffusion pattern, and eliminating flow dead zones and secondary turbulence. The coordinated cooperation of angles α and β ensures uniform flow distribution and stable flow in the first biomimetic topology guiding unit 8, achieving efficient connection between the first biomimetic topology guiding unit 8 and the biomimetic spider web liquid cooling unit, improving the overall flow field and temperature field distribution, and enhancing the overall heat dissipation performance and structural reliability of the battery.

[0076] In some specific embodiments, the angle α between the inlet channel 82 and the first channel 62 of the first biomimetic spider web liquid cooling unit 6 is designed to be 80°, and the angle β between the outlet channel 83 and the first channel of the second biomimetic spider web liquid cooling unit 7 is designed to be 100°. This angle design can maximize the aforementioned effects and further improve the flow stability, temperature field distribution uniformity and structural reliability.

[0077] like Figure 1 and Figure 3As shown, the third biomimetic spider web liquid cooling unit 15 and the fourth biomimetic spider web liquid cooling unit 16 have the same structure, including a second central frame 153 and a second biomimetic spider web flow channel disposed around the second central frame 153; the second biomimetic spider web flow channel includes a second main flow channel 151 and a second flow channel 152. The second main flow channel 151 is symmetrically distributed on both sides of the second central frame 153 and extends radially. Between the second main flow channels 151 on both sides of the second central frame 153, there are multiple second flow channels 152 symmetrically distributed relative to the second central frame 153 in a spider web shape; the second biomimetic topology guiding unit 17 includes a guide plate disposed corresponding to the guiding main flow channel 81, so that guiding channels are formed on both sides of the guide plate. The liquid flow channels of the second liquid cooling layer 5 completely cover the non-liquid flow channel areas of the first liquid cooling layer 4 except for the first central frame 63. Specifically, the second main flow channel 151 covers the first main flow channel 61, and the second flow channel 152 is staggered with the first flow channel 62, so that the second flow channel 152 covers the non-first flow channel 62 areas on both sides of the first main flow channel 62. The flow channel formed by the second biomimetic topology flow guiding unit 17 can cover the non-flow channel areas of the first biomimetic topology flow guiding unit 8 as well as the inlet flow channel 82 and outlet flow channel 83 areas. This achieves an innovative dual-layer differentiated staggered flow channel structure, breaking through the design limitations of traditional straight channels, serpentine channels, and single-layer biomimetic spider web flow channels. By utilizing the complementary coverage of the upper and lower flow channels, it eliminates heat exchange blind spots and local hot spots in the battery module, significantly improving the temperature uniformity of the entire battery pack under high-rate discharge conditions. Under continuous high-rate discharge conditions of 3C to 5C, the maximum temperature difference of the entire pack can be controlled within 3.5 to 5℃, fundamentally avoiding the risk of inconsistent cell aging and thermal runaway induced by local overheating.

[0078] like Figure 6 As shown, the thickness b of the first liquid cooling layer 4 and the second liquid cooling layer 5 is 2.8~3.2mm, and the thickness a of the heat insulation plate 14 is 1.8~2.2mm. In some specific embodiments, the thickness a of the heat insulation plate 14 is 2mm, the thickness b of the first liquid cooling layer 4 and the second liquid cooling layer 5 is 3mm, and the total thickness c of the liquid cooling device is 12mm. The thickness of the liquid cooling layer accounts for more than 50% of the total thickness of the liquid cooling device, which significantly improves the heat dissipation efficiency.

[0079] Example 2

[0080] This embodiment provides a design method for the liquid cooling device for battery heat dissipation described in Embodiment 1, the steps of which are as follows:

[0081] Step 1: Obtain the dimensions of the battery module (e.g., length L, width W, unit: mm) and the continuous discharge rate C. rate Maximum permissible installation thickness (H) of liquid cooling unit max (Unit: mm)

[0082] Step 2: Determine the heat dissipation conditions based on the continuous discharge rate, and match different flow channel design benchmark constraints for different heat dissipation conditions, as follows:

[0083] If the continuous discharge rate C rate If the temperature is ≤2C, it is considered a low-speed energy storage condition. The core design constraints are low flow resistance and reduced pumping energy consumption.

[0084] If 2C < C rate ≤3C indicates the medium-rate operating condition of in-vehicle fast charging, and the core design constraint is the balance between temperature uniformity and flow resistance;

[0085] If 3C < C rate ≤5C indicates a high-rate, high-power operating condition, and the core design constraints are to enhance local convection and reduce the overall temperature difference of the package.

[0086] Step 3: Determine the flow channel parameters of the first biomimetic spider web liquid cooling unit and the second biomimetic spider web liquid cooling unit in the first liquid cooling layer, as well as the flow channel parameters of the first biomimetic topology guiding unit, based on the heat dissipation conditions and the size of the battery module, to obtain the first liquid cooling layer.

[0087] Step 3.1: Determine the position of the first center frame of the first bionic spider web liquid cooling unit and the second bionic spider web liquid cooling unit according to the size of the battery module.

[0088] The position of the first center frame can be designed according to the actual size of the battery module. For example, if the position of the first center frame can be set at 0.25L, then the first biomimetic topology flow guiding unit can be set in the middle of the two first center frames.

[0089] Step 3.2: Determine the inlet width D1 of the first main flow channel, the width D2 of the first flow channel, and the flow channel size D3 of the first biomimetic topology guiding unit based on the heat dissipation conditions.

[0090] If it is a low-speed energy storage condition, then D1∈[3.5,4.0] mm, D2∈[12,15] mm, and D3= D2;

[0091] If it is a vehicle fast charging medium rate condition, then D1∈[3.0,3.5] mm, D2∈[10,12] mm, D3= D2;

[0092] If it is a high-rate, high-power operating condition, then D1∈[2.5,3.0] mm, D2∈[7,10] mm, and D3= D2.

[0093] Step 3.3: Determine the number of first flow channels n1 based on the size of the battery module and the width D2 of the first flow channel.

[0094] Step 3.4: Determine the angle α between the inlet channel 82 and the first channel 62 of the first biomimetic spider web liquid cooling unit 6, the angle β between the outlet channel 83 and the first channel of the second biomimetic spider web liquid cooling unit 7, and the angle γ between the first channel 62 and the first main channel 61.

[0095] Regarding α: The uniform value range is 75°≤α≤90°, and the near-right-angle structure smoothly introduces the coolant and suppresses eddy backflow; among them, the range is 85°~90° for low-speed energy storage conditions and 75°~80° for high-rate and high-power conditions.

[0096] Regarding β: The unified value range is 95°≤β≤110°, and the micro-obtuse angle directional jet docks with the secondary flow channel; among them, the range is 95°~100° for low-rate energy storage conditions and 105°~110° for high-rate and high-power conditions.

[0097] Regarding γ: The uniform value range is 85°≤γ≤110°, which smooths the flow and reduces local pressure loss.

[0098] Step 4: Based on the first liquid cooling layer, a second liquid cooling layer is obtained using differentiated topology parameters, so that the liquid flow channels of the second liquid cooling layer completely cover the non-liquid flow channel area of ​​the first liquid cooling layer except for the first central frame.

[0099] Projection coverage verification criteria: The blank area of ​​the upper flow channel projection is 100% covered by the lower flow channel projection, and the blank area of ​​the lower flow channel projection is 100% covered by the upper flow channel projection, with no heat exchange blind spots; if the verification is not met, the width of the lower second flow channel is slightly adjusted by 5% to 10% and re-verified until the full coverage condition is met.

[0100] Step 5: Based on the maximum allowable installation thickness H of the liquid cooling device max The thicknesses of the first liquid cooling layer, the second liquid cooling layer, and the heat insulation plate are determined to obtain the liquid cooling device.

[0101] The base thickness of the single-layer flow channel is 3mm, the thickness of the heat-insulating plates on both sides of the double-layer flow channel and the layer is 2mm, and the total theoretical thickness of the double-layer flow channel substrate is H. theory =2+3+2+3+2=12mm.

[0102] Thickness verification logic: If H max ≥12mm, adopting a standard integrated double-layer structure, i.e., a thickness design of 12mm; if H max <12mm, simultaneously and proportionally reduce the width of the single-layer flow channel and the thickness of the insulation board to ensure that the reduction ratio of the interlayer heat exchange area is less than 10%.

[0103] Once the liquid cooling device is designed, it can be mass-produced using precision CNC milling and separate brazing, or manufactured using a metal 3D printing integrated molding process.

[0104] Example 3

[0105] like Figure 10 and Figure 11 As shown, this embodiment provides a battery, including a battery box, several layers of battery modules disposed within the battery box, and a liquid cooling device 13 for battery heat dissipation as described in Embodiment 1 disposed between each layer of battery modules.

[0106] In this embodiment, a two-layer module is used as an example, namely a first module 11 and a second module 12. Each module is composed of multiple battery cells. A liquid cooling device 13 is installed between the first module 11 and the second module 12 to dissipate heat from the first module 11 and the second module 12. In order to further reduce the contact thermal resistance, a thermally conductive material is coated or a thermally conductive pad is provided on the contact surface between the module and the liquid cooling device 13.

[0107] During operation, the cooling medium is introduced from the main water inlet 2 of the housing 1, and then flows into the first liquid cooling layer 4 and the second liquid cooling layer 5 through the first water inlet 9 of the first liquid cooling layer 4 and the second water inlet 18 of the second liquid cooling layer 5, respectively. It then flows sequentially through the first biomimetic spider web liquid cooling unit 6, the first biomimetic topology flow guiding unit 8 and the second biomimetic spider web liquid cooling unit 7 of the first liquid cooling layer 4, and the third biomimetic spider web liquid cooling unit 15, the second biomimetic topology flow guiding unit 17 and the fourth biomimetic spider web liquid cooling unit 16 of the second liquid cooling layer 5. Finally, it flows out through the first water outlet 10 and the second water outlet 19 of the two liquid cooling layers to the main water outlet 3 of the housing 1, thus dissipating heat for the two modules.

[0108] Example 4

[0109] This embodiment uses the method in Embodiment 2, targeting a battery module with dimensions L=1000mm, W=514mm, and a continuous discharge rate C. rate Under the condition of 3C, the double-layer staggered channel liquid cooling device of Example 1 was designed. The center of the first central frame is located at 0.25L, D1=3.5 mm, D2=D3=10 mm, n1=24, α=80°, β=100°, γ=98°; the base thickness of the single-layer flow channel is 3mm, the thickness of the heat-insulating plates on both sides of the double-layer flow channel and the layer is 2mm, and the total thickness of the liquid cooling device is 12mm.

[0110] To verify the cooling and temperature uniformity control effects of the liquid cooling device provided by the present invention on power batteries, this embodiment builds a fluid-solid coupled thermal simulation model under the same working conditions, and compares the above-mentioned double-layer staggered channel liquid cooling device with a single-layer flow channel cold plate (i.e., adopting the first liquid cooling layer structure of the present invention) and a double-layer isomorphic channel cold plate (i.e., both upper and lower cold plates adopt the first liquid cooling layer structure of the present invention) through benchmark simulation.

[0111] This simulation experiment uniformly sets boundary conditions and physical parameters to ensure that the simulation environment for the three comparative structures is completely consistent, eliminating variable interference. Specific simulation parameters are shown in Table 1 below. Temperature data was extracted after the simulation conditions reached a stable state. The results are as follows: Figures 12-14 .

[0112] Table 1 Simulation Operating Conditions

[0113]

[0114] Depend on Figures 12-14 It can be seen that when using a single-layer flow channel cold plate heat dissipation scheme, the highest steady-state temperature of the battery cell is 31℃; when using a double-layer isomorphic channel cold plate heat dissipation scheme, the highest steady-state temperature of the battery cell is 30.2℃; and when using the heat dissipation scheme of the double-layer staggered channel liquid cooling device of this invention, the highest steady-state temperature of the battery cell is only 29.4℃. The simulation data comparison shows that, compared with single-layer flow channel cold plates and double-layer isomorphic channel cold plates, the double-layer staggered channel structure of this invention has significant technical advantages:

[0115] Firstly, this invention effectively reduces the maximum temperature limit of the power battery cell, with a temperature reduction of 2°C compared to the single-layer flow channel structure and 1°C compared to the double-layer isomorphic channel structure. This can effectively suppress the temperature rise accumulation during the continuous high-power heat release process of the power battery, reduce the risk of thermal runaway of the cell, and improve the safety of the battery system at high temperatures.

[0116] Secondly, the special flow channel layout of the double-layer staggered channel of the present invention breaks through the limitations of fluid heat exchange in double-layer isomorphic channels and single-layer channels. The staggered flow channel can achieve full coverage of the entire heat exchange area of ​​the cold plate, optimize the contact heat exchange path between the cold plate and the power battery cell, improve the flow velocity distribution and heat exchange uniformity of the cooling medium inside the flow channel, avoid the problem of local heat exchange blind spots and uneven fluid heat exchange that exist in traditional structures, and significantly improve the temperature uniformity of the entire power battery pack.

[0117] In summary, by setting up a double-layer staggered channel structure, this invention balances heat dissipation and cooling capacity with overall temperature uniformity under the same cooling medium, flow rate, and cell heating conditions. It effectively solves the technical defects of low heat exchange efficiency of traditional single-layer cold plates and poor temperature uniformity of double-layer isomorphic cold plates, significantly improving the overall heat dissipation performance of the power battery liquid cooling system. It can effectively adapt to the heat dissipation requirements of continuous high-rate operation of power batteries and ensure the long-term safe and stable operation of batteries.

[0118] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A liquid cooling device for battery heat dissipation, characterized in that, It includes a housing and a first liquid cooling layer and a second liquid cooling layer disposed within the housing; The first liquid cooling layer includes a first biomimetic topology flow guiding unit and a first biomimetic spider web liquid cooling unit and a second biomimetic spider web liquid cooling unit connected to both sides of the first biomimetic topology flow guiding unit; the first biomimetic spider web liquid cooling unit and the second biomimetic spider web liquid cooling unit have the same structure, including a first central frame and a first biomimetic spider web flow channel disposed around the first central frame. The second liquid cooling layer includes a second biomimetic topology flow guiding unit and a third biomimetic spider web liquid cooling unit and a fourth biomimetic spider web liquid cooling unit disposed on both sides of the second biomimetic topology flow guiding unit; The first liquid cooling layer and the second liquid cooling layer are separated by a heat insulation plate, and the liquid flow channel of the second liquid cooling layer completely covers the non-liquid flow channel area of ​​the first liquid cooling layer except for the first central frame.

2. The liquid cooling device for battery heat dissipation according to claim 1, characterized in that, The first biomimetic spider web flow channel includes a first main flow channel and a first flow channel. The first main flow channel is symmetrically distributed on both sides of the first central frame and extends radially. Between the first main flow channels on both sides of the first central frame, there are multiple first flow channels in a spider web shape that are symmetrically distributed relative to the first central frame.

3. The liquid cooling device for battery heat dissipation according to claim 2, characterized in that, The width of the first main channel gradually increases from the first center frame outwards, and the angle between the first main channel and the first flow channel is 85°~110°.

4. The liquid cooling device for battery heat dissipation according to claim 2, characterized in that, The first biomimetic topology flow guiding unit includes a main flow guiding channel and an inlet flow channel and an outlet flow channel respectively disposed on both sides of the main flow guiding channel. The inlet flow channel is connected to the first flow channel of the first biomimetic spider web liquid cooling unit, and the outlet flow channel is connected to the first flow channel of the second biomimetic spider web liquid cooling unit. The angle between the inlet channel and the first channel of the first biomimetic spider web liquid cooling unit is 75°~90°. The angle between the outlet channel and the first channel of the second biomimetic spider web liquid cooling unit is 95°~110°.

5. The liquid cooling device for battery heat dissipation according to claim 4, characterized in that, The third and fourth biomimetic spider web liquid cooling units have the same structure, including a second central frame and a second biomimetic spider web flow channel located around the second central frame. The second biomimetic spider web flow channel includes a second main flow channel and a second flow channel. The second main flow channel is symmetrically distributed on both sides of the second central frame and extends radially. Between the second main flow channels on both sides of the second central frame, there are multiple second flow channels in a spider web pattern that are symmetrically distributed relative to the second central frame. The second main channel covers the first main channel, and the second channel is staggered with the first channel, so that the second channel covers the non-first channel areas on both sides of the first main channel; And / or, the second biomimetic topology flow guiding unit includes a flow guiding plate disposed corresponding to the main flow guiding channel, so that flow guiding channels are formed on both sides of the flow guiding plate.

6. The liquid cooling device for battery heat dissipation according to claim 1, characterized in that, The shell is provided with a main water inlet and a main water outlet at both ends. The first bionic spider web liquid cooling unit and the third bionic spider web liquid cooling unit are respectively provided with a first water inlet branch and a second water inlet branch connected to the main water inlet. The second bionic spider web liquid cooling unit and the fourth bionic spider web liquid cooling unit are respectively provided with a first water outlet branch and a second water outlet branch connected to the main water outlet. And / or, the thickness of the first liquid cooling layer and the second liquid cooling layer is 2.8~3.2mm, and the thickness of the heat insulation plate is 1.8~2.2mm.

7. A design method for a liquid cooling device for battery heat dissipation as described in any one of claims 1 to 6, characterized in that, include: Obtain the dimensions of the battery module, the continuous discharge rate, and the maximum allowable installation thickness of the liquid cooling device; Determine heat dissipation conditions based on continuous discharge rate; Based on the heat dissipation conditions and the size of the battery module, the flow channel parameters of the first biomimetic spider web liquid cooling unit and the second biomimetic spider web liquid cooling unit in the first liquid cooling layer, as well as the flow channel parameters of the first biomimetic topology guiding unit, are determined to obtain the first liquid cooling layer. Based on the first liquid cooling layer, a second liquid cooling layer is obtained by using differentiated topology parameters, so that the liquid flow channels of the second liquid cooling layer completely cover the non-liquid flow channel area of ​​the first liquid cooling layer except for the first central frame. The thicknesses of the first liquid cooling layer, the second liquid cooling layer, and the insulation plate are determined based on the maximum allowable installation thickness of the liquid cooling device, thus obtaining the liquid cooling device.

8. The design method of the liquid cooling device for battery heat dissipation according to claim 7, characterized in that, The method of determining the heat dissipation condition based on the continuous discharge rate includes: If the continuous discharge rate C rate If the temperature is ≤2C, it is considered a low-speed energy storage condition. The core design constraints are low flow resistance and reduced pumping energy consumption. If 2C < C rate ≤3C indicates the medium-rate operating condition of onboard fast charging, and the core design constraint is the balance between temperature uniformity and flow resistance; If 3C < C rate ≤5C indicates a high-rate, high-power operating condition, and the core design constraints are to enhance local convection and reduce the overall temperature difference of the package.

9. The design method of the liquid cooling device for battery heat dissipation according to claim 7, characterized in that, The determination of the flow channel parameters of the first biomimetic spiderweb liquid cooling unit and the second biomimetic spiderweb liquid cooling unit, as well as the flow channel parameters of the first biomimetic topology guiding unit in the first liquid cooling layer, based on the heat dissipation conditions and the size of the battery module, includes: The positions of the first center frames of the first and second biomimetic spider web liquid cooling units are determined based on the size of the battery module. The width of the first main channel inlet D1, the width of the first flow channel D2, and the flow channel size D3 of the first biomimetic topological flow guiding unit are determined according to the heat dissipation conditions: If it is a low-speed energy storage condition, then D1∈[3.5,4.0] mm, D2∈[12,15] mm, D3= D2; if it is a medium-rate vehicle fast charging condition, then D1∈[3.0,3.5] mm, D2∈[10,12] mm, D3= D2; if it is a high-rate high-power condition, then D1∈[2.5,3.0] mm, D2∈[7,10] mm, D3= D2. The number of first flow channels n1 is determined based on the size of the battery module and the width D2 of the first flow channel.

10. A battery, characterized in that, It includes a battery box, several layers of battery modules disposed within the battery box, and a liquid cooling device for battery heat dissipation as described in any one of claims 1 to 6 disposed between the layers of battery modules.

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