A battery pack liquid cooling plate structure based on trapezoidal cross-section flow channel

Abstract

The utility model discloses a kind of battery pack liquid cooling plate structures based on trapezoidal section flow channel, including liquid cooling plate main body, several trapezoidal flow channels are sequentially penetrated in liquid cooling plate main body, and the width-height ratio b / a of trapezoidal flow channel is 1.6~2.0;The height ratio h / a of trapezoidal flow channel is 1.2~1.6;The angle θ of trapezoidal flow channel side wall and lower bottom is 30 °~60 °;The flow channel wall thickness d of trapezoidal flow channel is 1.8mm~3.0mm, it is related to new energy power battery thermal management technical field, adopt trapezoidal section flow channel design, by optimizing width-height ratio, height ratio, angle and flow channel wall thickness etc. Parameter, maximum bearing capacity, heat dissipation efficiency and temperature uniformity are improved. The gradually expanding section configuration of trapezoidal flow channel can induce secondary flow phenomenon, enhance thermal boundary layer disturbance, and improve heat transfer efficiency. Meanwhile, the design reduces frictional resistance by width-height ratio optimization, and regulates turbulent kinetic energy by height ratio, effectively balances pressure drop and heat transfer performance.

Description

Technical Field

[0001] This utility model belongs to the field of thermal management technology for new energy power batteries, specifically a battery pack liquid cooling plate structure based on a trapezoidal cross-section flow channel. Background Technology

[0002] With the continuous improvement of power battery energy density, the heat dissipation performance of battery thermal management systems has become a core factor restricting battery pack safety and lifespan. Traditional liquid cooling plates mostly adopt a rectangular cross-section flow channel design, which can easily lead to local overheating of the battery module due to uneven coolant flow velocity distribution. At the same time, the flow separation phenomenon caused by abrupt changes in the rectangular flow channel cross-section can significantly increase pressure drop loss and energy consumption. In existing technologies, key parameters such as the aspect ratio and height ratio of the flow channel lack systematic optimization. Often, the pursuit of heat transfer area leads to flow velocity decay and a decrease in convective heat transfer coefficient. Moreover, conventional structures cannot balance the contradictory relationship between heat dissipation efficiency and pressure drop loss. At the manufacturing process level, traditional welded flow channels have the risk of weld defects, while rectangular flow channel extrusion molding presents significant mold stress concentration problems, resulting in low yield and insufficient mold life. In addition, existing liquid cooling plates generally face fatigue failure problems caused by thermal stress concentration, and are prone to structural cracks and sealing failures during long-term charge-discharge cycles. To address the aforementioned technical bottlenecks, there is an urgent need to develop a novel liquid cooling plate flow channel design that combines efficient heat transfer characteristics, excellent structural reliability, and process adaptability, in order to meet the stringent heat dissipation requirements of high-power-density battery modules and reduce the total life-cycle cost. Utility Model Content

[0003] The purpose of this invention is to provide a battery pack liquid cooling plate structure based on a trapezoidal cross-section flow channel to solve the problems mentioned in the background art.

[0004] The technical solution adopted in this utility model is as follows:

[0005] A battery pack liquid cooling plate structure based on trapezoidal cross-section flow channels includes a liquid cooling plate body. The liquid cooling plate body has several trapezoidal flow channels that are sequentially connected end-to-end. The width-to-height ratio b / a of the trapezoidal flow channels is 1.6–2.0; the height ratio h / a of the trapezoidal flow channels is 1.2–1.6; the angle θ between the sidewall and the bottom of the trapezoidal flow channel is 30°–60°; and the wall thickness d of the trapezoidal flow channels is 1.8 mm–3.0 mm.

[0006] Where a is the width of the upper base of the trapezoidal flow channel, b is the width of the lower base of the trapezoidal flow channel, h is the height of the trapezoidal flow channel, d is the wall thickness of the trapezoidal flow channel, and θ is the angle between the side wall and the lower base of the trapezoidal flow channel.

[0007] Preferably, the liquid cooling plate body is made of high-strength aluminum alloy through a precision extrusion process, the trapezoidal flow channel runs through its front and rear ends, and several trapezoidal flow channels are connected end to end in sequence to form a continuous coolant circulation channel, and the inner wall surface of the trapezoidal flow channel is smooth.

[0008] Preferably, the liquid cooling plate body is provided with side beams on both the left and right sides, and the liquid cooling plate body is provided with front beams and rear beams on the front and rear sides respectively. The front beam is provided with two water nozzles, and the two water nozzles are respectively connected to the trapezoidal flow channels on the two outer sides of the liquid cooling plate body.

[0009] Preferably, the liquid cooling plate body is provided with several central beams on both the upper and lower sides for fixing the liquid cooling plate structure body.

[0010] Preferably, the bottom front and rear ends of the liquid cooling plate body are respectively provided with a front sealing block and a rear sealing block, and the front sealing block is provided with two water nozzles, which are respectively connected to the trapezoidal flow channels on the two outer sides of the liquid cooling plate body.

[0011] Preferably, the bottom of the liquid cooling plate body is provided with several load-bearing base supports parallel to the front sealing block, and the top of the liquid cooling plate body is provided with several crossbeams parallel to the front sealing block. Both the load-bearing base supports and the crossbeams adopt an embedded structure.

[0012] In summary, due to the adoption of the above technical solution, the beneficial effects of this utility model are:

[0013] This invention employs a trapezoidal cross-section flow channel design. By optimizing parameters such as aspect ratio, height ratio, included angle, and channel wall thickness, it improves maximum load-bearing capacity, heat dissipation efficiency, and temperature uniformity. The gradually expanding cross-section configuration of the trapezoidal flow channel induces secondary flow phenomena, enhances thermal boundary layer disturbance, and improves heat transfer efficiency. Simultaneously, this design reduces frictional resistance through aspect ratio optimization and effectively balances pressure drop and heat transfer performance by controlling turbulent kinetic energy through height ratio regulation. Furthermore, the sectional moment of inertia characteristics of the trapezoidal cross-section disperse cyclic thermal loads, improving load-bearing capacity and structural strength. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a partial flow channel structure of the present invention;

[0015] Figure 2 This is a schematic diagram of the liquid cooling plate structure of this utility model;

[0016] Figure 3 This is a cross-sectional view of the liquid cooling plate structure of this utility model;

[0017] Figure 4 This is a schematic diagram of another embodiment of the liquid cooling plate structure of this utility model.

[0018] Figure 5This is a schematic diagram of the liquid cooling plate structure of this utility model;

[0019] Figure 6 This is a two-section view of the liquid cooling plate structure of this utility model;

[0020] In the diagram: 1. Liquid cooling plate main body; 2. Side beam; 3. Front beam; 4. Rear beam; 5. Middle beam; 6. Water nozzle; 7. Front sealing block; 8. Rear sealing block; 9. Load-bearing base; 10. Crossbeam. Detailed Implementation

[0021] The specific embodiments of this utility model are described in detail below.

[0022] The "range" disclosed in this utility model is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 10–50 is listed for a specific parameter, it is also expected that ranges of 10–40 and 20–50 are also included. Furthermore, if the minimum range values ​​are listed as 1 and 2, and the maximum range values ​​are listed as 3, 4, and 5, then the following ranges are all expected: 1–3, 1–4, 1–5, 2–3, 2–4, and 2–5. In this application, unless otherwise stated, the numerical range "a–b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0–5" means that all real numbers between "0–5" have been listed herein; "0–5" is merely a shortened representation of these numerical combinations.

[0023] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0024] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0025] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0026] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0027] Unless otherwise specified, the reaction will proceed under normal temperature and pressure conditions.

[0028] Unless otherwise specified, all parts or percentages are by weight or by weight percentage.

[0029] In this invention, all the substances used are known substances that can be purchased or synthesized by known methods.

[0030] In this invention, all the devices or equipment used are conventional devices or equipment known in the art and are readily available.

[0031] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0032] Example 1:

[0033] A battery pack liquid cooling plate structure based on a trapezoidal cross-section flow channel, such as Figure 1 As shown, the device includes a liquid cooling plate body 1, which contains several trapezoidal flow channels that are sequentially connected end to end. The width-to-height ratio b / a of the trapezoidal flow channels is 1.6 to 2.0; the height ratio h / a of the trapezoidal flow channels is 1.2 to 1.6; the angle θ between the sidewall and the bottom of the trapezoidal flow channels is 30° to 60°; and the wall thickness d of the trapezoidal flow channels is 1.8 mm to 3.0 mm.

[0034] Where a is the width of the upper base of the trapezoidal flow channel, b is the width of the lower base of the trapezoidal flow channel, h is the height of the trapezoidal flow channel, d is the wall thickness of the trapezoidal flow channel, and θ is the angle between the side wall and the lower base of the trapezoidal flow channel.

[0035] In one possible implementation, the width-to-height ratio b / a of the trapezoidal flow channel is 1.6; the height ratio h / a of the trapezoidal flow channel is 1.2; the angle θ between the sidewall and the bottom of the trapezoidal flow channel is 30°; and the wall thickness d of the trapezoidal flow channel is 1.8 mm.

[0036] In one possible implementation, the width-to-height ratio b / a of the trapezoidal flow channel is 1.8; the height ratio h / a of the trapezoidal flow channel is 1.4; the angle θ between the sidewall and the bottom of the trapezoidal flow channel is 50°; and the wall thickness d of the trapezoidal flow channel is 2.9 mm.

[0037] In one possible implementation, the width-to-height ratio b / a of the trapezoidal flow channel is 2.0; the height ratio h / a of the trapezoidal flow channel is 1.6; the angle θ between the sidewall and the bottom of the trapezoidal flow channel is 60°; and the wall thickness d of the trapezoidal flow channel is 3.0 mm.

[0038] In one possible implementation, the liquid cooling plate body 1 is made of high-strength aluminum alloy through a precision extrusion process, with trapezoidal flow channels running through its front and rear ends, and several trapezoidal flow channels being connected end to end in sequence to form a continuous coolant circulation channel, and the inner wall surface of the trapezoidal flow channels is smooth.

[0039] In one possible implementation, the liquid cooling plate body 1 is provided with side beams 2 on both the left and right sides, and the liquid cooling plate body 1 is provided with front beams 3 and rear beams 4 on the front and rear sides respectively. The front beam 3 is provided with two water nozzles 6, and the two water nozzles 6 are respectively connected to the trapezoidal flow channels on the two outer sides of the liquid cooling plate body 1.

[0040] Furthermore, several central beams 5 are provided on both the upper and lower sides of the liquid cooling plate body 1 to fix the liquid cooling plate structure body.

[0041] In one possible implementation, the bottom front and rear ends of the liquid cooling plate body 1 are respectively provided with a front sealing block 7 and a rear sealing block 8. The front sealing block 7 is provided with two water nozzles 6, which are respectively connected to the trapezoidal flow channels on the two outer sides of the liquid cooling plate body 1.

[0042] Furthermore, the bottom of the liquid cooling plate body 1 is provided with several load-bearing base supports 9 parallel to the front sealing block 7, and the top of the liquid cooling plate body 1 is provided with several crossbeams 10 parallel to the front sealing block 7. Both the load-bearing base supports 9 and the crossbeams 10 adopt an embedded structure.

[0043] Example 2:

[0044] A liquid-cooled plate structure includes a liquid-cooled plate body 1, side beams 2, water nozzles 6, front beams 3, rear beams 4, and a middle beam 5, as shown below. Figure 2 As shown, the liquid cooling plate illustrated is suitable for 48 / 52 cell battery packs. The water nozzle 6 is formed using precision machining, ensuring the dimensional and shape accuracy of all components. The main flow channel 5 is formed from high-strength aluminum alloy profiles through a precision extrusion process, creating a continuous, interconnected coolant circulation channel within. Figure 3As shown, the liquid cooling plate's flow channel cross-section adopts a trapezoidal design. The trapezoidal cross-section parameters satisfy the aspect ratio b / a = 1.8 ± 0.2, the height ratio h / a = 1.4 ± 0.2, the included angle θ = 45° ± 15°, and the flow channel wall thickness d = 1.8 mm - 3.0 mm. This structure has been optimized for fluid dynamics, which can significantly reduce the pressure drop loss during coolant flow while ensuring high-efficiency heat exchange performance. The front beam 3, rear beam 4, and middle beam 5 are all manufactured through secondary processing of profiles, and their cross-sectional shapes are specially designed, which not only ensures the processing accuracy of the components but also effectively reduces production costs and improves production efficiency. In addition, the liquid cooling plate body 1, side beam 2, water nozzle 6, front beam 3, rear beam 4, and middle beam 5 are welded together using argon arc welding, thereby ensuring the mechanical strength, sealing performance, and long-term reliability of the overall liquid cooling plate structure. The battery module is fixed to the rear beam 4 and the middle beam 5 by bolts. Different numbers of battery cells can be accommodated by adjusting the extrusion length of the liquid cooling plate body 1 and the distance between the middle beam 5 and the rear beam 4. The cross-sectional shapes of the front beam 3, middle beam 5, and rear beam 4 have been optimized, which not only improves the overall rigidity and strength of the structure but also reduces the amount of material used, thereby lowering production costs.

[0045] In practical applications, the liquid cooling plate of this embodiment can be widely used in the cooling systems of various battery modules, especially in electric vehicles and energy storage systems, where it has broad application prospects. Figure 4 As shown, the liquid cooling plate structure of this embodiment can be flexibly adapted to different specifications and quantities of battery cells by adjusting the extrusion length of the profile of the liquid cooling plate body 1, the distance between the middle beam 5 and the rear beam 4, as well as the number and position of the middle beam 5, to meet diverse application needs. Furthermore, the application of argon arc welding ensures the sealing and reliability of the overall structure of the liquid cooling plate, maintaining good performance even during long-term use. The liquid cooling plate of this embodiment not only has excellent heat dissipation performance and good economy, but also high structural strength and reliability, making it suitable for the cooling needs of various high-power-density battery modules.

[0046] like Figure 1As shown, the main flow channel in this embodiment adopts a trapezoidal structure design, specifically a gradually expanding cross-section configuration, where the width of the lower base b is greater than the width of the upper base a. This design significantly improves the uniformity of the cooling medium distribution within the flow channel, effectively suppressing the formation of local flow dead zones, thereby enhancing overall heat dissipation performance. The inclined sidewall configuration of the flow channel can induce secondary flow phenomena such as Dean vortices. This flow characteristic not only enhances the disturbance effect of the thermal boundary layer but also significantly improves heat transfer efficiency. The trapezoidal inclined surface configuration design of this embodiment effectively suppresses flow separation phenomena, avoiding the flow instability problem caused by abrupt changes in cross-section in traditional flow channels. By optimizing the cross-sectional parameters of the flow channel to match the dynamic operating conditions, this embodiment ensures a stable linear correspondence between flow velocity and heat transfer efficiency. This design fundamentally avoids the pressure oscillation problem that is prone to occur in traditional variable cross-section flow channels under conditions of sudden changes in flow rate, thereby improving the stability and reliability of the system. Specifically, the trapezoidal flow channel design in this embodiment achieves performance optimization through the following mechanisms: First, the gradually expanding cross-section configuration makes the flow of the cooling medium within the channel more uniform, reducing the formation of local high-temperature regions; second, the secondary flow phenomenon induced by the inclined sidewalls enhances the fluid mixing effect, further improving heat transfer efficiency; finally, the design of constant cross-sectional parameters ensures a linear relationship between flow velocity and heat transfer efficiency under different operating conditions, avoiding pressure fluctuations and energy losses caused by sudden changes in flow rate in traditional variable cross-section flow channels. The trapezoidal flow channel design in this embodiment, through its gradually expanding cross-section configuration, the secondary flow phenomenon induced by the inclined sidewalls, and the optimization of constant cross-sectional parameters, not only significantly improves heat transfer efficiency and flow uniformity but also effectively reduces frictional resistance and pressure oscillations, demonstrating significant engineering application value and market potential.

[0047] In terms of structural reliability, the trapezoidal cross-section design adopted in this embodiment has significant mechanical advantages. The moment of inertia characteristics of the trapezoidal cross-section are superior to those of the traditional rectangular structure, which can effectively disperse the periodic thermal load generated by the battery pack during charge-discharge cycles. At the same time, the local stress peak of the trapezoidal cross-section structure is reduced by 30%-40% compared with the rectangular structure, thereby significantly improving the fatigue resistance and long-term reliability of the structure. Furthermore, the main flow channel 5 is manufactured using a high-strength aluminum alloy extrusion molding process, which ensures the integrity and consistency of the inner wall of the flow channel and avoids weld or joint defects common in traditional welded structures. Experimental data shows that the flow channel structure using a single extrusion molding process has a fatigue life that is more than three times longer than that of the traditional welded structure, meeting the reliability requirements of more than 100,000 charge-discharge cycles. This performance improvement is mainly due to the high-quality inner wall surface and uniform material distribution achieved by the single extrusion molding process, which effectively reduces the risk of stress concentration and crack initiation. In addition, the trapezoidal cross-section design also has good deformation resistance and structural stability, enabling it to withstand large thermal and mechanical stresses during the charge-discharge process of the battery pack. This invention, through a combination of trapezoidal cross-section design and single-extrusion molding process, not only significantly reduces local stress peaks but also greatly improves the fatigue life and reliability of the structure, meeting the long-term use requirements under high-frequency charge-discharge cycles. This design has significant practical implications for improving the overall performance and lifespan of battery modules.

[0048] At the engineering implementation level, the structural design of this embodiment fully considers the feasibility and economy of industrial production, and is particularly suitable for extrusion molding processes. This design significantly reduces the complexity of the mold structure by optimizing the cross-sectional shape and dimensional parameters of the flow channel, resulting in a substantial reduction in mold manufacturing and maintenance costs. Data shows that using extrusion molding, the yield rate of a single molding cycle can be increased to over 90%, approximately 20% higher than traditional processes. Furthermore, because extrusion molding wastes very little material, the material utilization rate is as high as 95%, while the material utilization rate of traditional milling processes is only around 60%, thus significantly reducing raw material costs. Further, this embodiment can flexibly adapt to the differentiated heat dissipation requirements of different types of battery modules by adjusting core parameters such as the top bottom width 'a' and the aspect ratio 'k'. This design is compatible with square batteries, cylindrical batteries, and pouch battery modules, covering more than 90% of mainstream power battery specifications. For example, for square battery modules, the heat dissipation contact area can be increased by increasing the width 'a' of the top base; for cylindrical battery modules, the fit between the flow channel and the battery surface can be optimized by adjusting the aspect ratio 'k'; and for pouch battery modules, the cross-sectional shape can be fine-tuned to adapt to their flexible characteristics. This highly flexible design makes this embodiment widely applicable in practical applications.

[0049] In terms of large-scale production, the structural design of this embodiment not only reduces the production cost per unit but also significantly improves production efficiency. Due to the continuous production characteristics of extrusion molding, combined with the optimized design of this embodiment, efficient and stable batch production can be achieved. According to actual production data, the liquid cooling plate designed in this embodiment reduces the large-scale production cost by approximately 30% compared to traditional processes, while shortening the production cycle by more than 25%. These advantages give this embodiment significant economic benefits and market competitiveness in industrial applications. At the engineering implementation level, this embodiment, through optimized structural design and process parameters, not only improves production efficiency and product yield but also significantly reduces material waste and production costs. Its flexible design parameters allow the liquid cooling plate to adapt to various types of battery modules, covering the vast majority of mainstream power battery specifications, demonstrating significant industrial application value and market promotion potential.

[0050] Example 3:

[0051] like Figure 5 As shown, this embodiment provides a highly efficient integrated liquid cooling plate structure, including a liquid cooling plate body 1, a crossbeam 10, a water nozzle 6, a front sealing block 7, a rear sealing block 8, and a load-bearing base 9. Figure 6 As shown, the internal cross-section of the liquid-cooled plate profile adopts a trapezoidal structure design. The trapezoidal cross-section parameters meet the following requirements: width-to-height ratio b / a = 1.8 ± 0.2, height ratio h / a = 1.4 ± 0.2, included angle θ = 45° ± 15°, and flow channel wall thickness d = 1.8 mm - 3.0 mm. By optimizing the flow channel geometry, the flow efficiency and heat exchange performance of the coolant are significantly improved, while effectively reducing the pressure drop within the flow channel, ensuring uniform distribution of the coolant and preventing localized overheating. Two crossbeams are embedded in the front of the liquid-cooled plate profile and are firmly connected to it through welding, enhancing the rigidity and deformation resistance of the overall structure. This ensures stability under external loads and prevents deformation or damage caused by vibration or impact. The inlet and outlet water nozzles are directly connected to the internal flow channels of the liquid-cooled plate and fixed by welding, ensuring efficient coolant input and output while improving the sealing and reliability of the connection points, preventing coolant leakage under high-pressure conditions. The front and rear sealing blocks are respectively located at both ends of the liquid cooling plate. Through precision machining and assembly, they connect and seal the internal flow channels, forming a complete sealed liquid cooling circuit. This effectively prevents coolant leakage and ensures the circulation efficiency of the coolant within the flow channels. Three parallel load-bearing base supports, made of high-strength materials, are installed at the bottom of the liquid cooling plate. By optimizing their distribution and fixing method, the load-bearing capacity and stability of the liquid cooling plate are significantly improved, enabling it to withstand greater external loads while reducing fatigue damage caused by long-term use.

[0052] This embodiment simplifies the production process, shortens the production cycle, and effectively reduces manufacturing costs through integrated design and modular assembly, while improving the overall performance and service life of the liquid cooling plate. Furthermore, the structural design of this embodiment fully considers assembly convenience and maintenance ease, making the installation and disassembly of the liquid cooling plate more efficient and facilitating subsequent maintenance and repair. The liquid cooling plate structure of this embodiment is suitable for the high-efficiency thermal management needs in fields such as new energy vehicles, energy storage systems, and industrial equipment. It effectively solves the problems of complex structures, high costs, and insufficient load-bearing capacity of traditional liquid cooling plates, and has broad application prospects and market value. Through actual testing, the liquid cooling plate of this embodiment outperforms traditional designs in terms of thermal management performance, structural strength, and service life, and can meet the requirements of high reliability, high efficiency, and high stability in thermal management.

[0053] Example 4:

[0054] A liquid cooling plate structure for a battery pack that enables uniform flow distribution includes a main flow channel profile, a water nozzle, and a crossbeam for fixing the battery; the cross section of the flow channel satisfies the following geometric parameter definitions:

[0055] Top base width: a (2.5~6.5)

[0056] Width of the bottom base: b = k·a (k = 1.6~2.0)

[0057] Channel height: h = m·a (m = 1.2~1.6)

[0058] Flow channel wall thickness: d = 1.8mm - 3.0mm

[0059] Included angle: θ = 45° ± 15°

[0060] Invariant cross-section characteristic: The geometric parameters (a, b, h, θ, d) of the flow channel cross-section are constant along the flow direction.

[0061] Regarding the optimization of the aspect ratio (k = b / a), experimental data shows that when the aspect ratio k is in the range of 1.6-2.0, the heat transfer contact area of ​​the liquid cooling plate increases significantly, and the thermal resistance decreases significantly, thereby effectively improving the temperature uniformity and heat dissipation efficiency of the liquid cooling plate. Specifically, increasing the aspect ratio k expands the contact area between the flow channel and the battery module, enhancing the heat conduction effect, and optimizing the flow distribution of the cooling medium, allowing heat to be transferred and dissipated more evenly. However, when the aspect ratio k exceeds the threshold, the increase in the equivalent diameter of the cross-section leads to a linear decrease in the flow velocity of the cooling medium, while also causing a decrease in the convective heat transfer coefficient, thus weakening the overall heat dissipation performance. Furthermore, from the perspective of molding process adaptability, setting the upper limit of the aspect ratio k to 2.0 can control the stress concentration factor of the extrusion die within a safe and reasonable range (usually below 1.5), thereby effectively extending the die's service life and improving production efficiency. At the same time, this restriction also helps to ensure molding quality and dimensional accuracy, avoid deformation, cracking or other defects caused by excessive mold stress, and ensure product consistency and reliability.

[0062] For optimizing the height ratio (m = h / a) parameter, experimental data show that when the height ratio m is in the range of 1.2-1.6, increasing the channel height can significantly improve the turbulent kinetic energy of the coolant, while reducing the vortex scale in the near-wall region and decreasing the thermal boundary layer thickness, thereby significantly improving the temperature uniformity and heat transfer efficiency of the liquid cooling plate. Increasing the channel height enhances the flow disturbance effect of the cooling medium, promoting the disruption and renewal of the thermal boundary layer, allowing heat to be transferred more efficiently from the battery module to the cooling medium. When the height ratio m exceeds 2.0, the nonlinear growth of the wetted perimeter causes a surge in frictional resistance, resulting in a pressure drop rate that significantly exceeds the improvement in heat transfer performance. This phenomenon not only deteriorates the flow stability of the liquid cooling plate but also accelerates the fatigue failure of the channel, reducing the system's reliability and service life. Excessive increases in the height ratio m lead to a significant increase in the contact area between the inner wall of the channel and the cooling medium, thereby significantly increasing flow resistance.

[0063] In the strategy for controlling the included angle θ, when θ is in the range of 30°-60°, the tapering structure of the trapezoidal sidewall can significantly enhance the intensity of the transverse secondary flow and improve fluid mixing efficiency. This design allows the cooling medium to form stronger vortex disturbances within the flow channel, thereby enhancing the disruption and renewal capability of the thermal boundary layer. Optimized design of the included angle θ achieves a fine balance between pressure drop and energy consumption, while significantly improving heat dissipation efficiency and temperature uniformity. However, when the included angle θ is less than 30°, flow separation intensifies, leading to an expansion of the low-speed vortex region and subsequently a surge in local pressure drop. This phenomenon creates a dead zone effect, causing a significant decrease in heat transfer efficiency, as well as an imbalance between pressure drop and energy consumption and a deterioration in temperature uniformity. If the included angle θ is too small, the guiding effect of the flow channel sidewall weakens, resulting in uneven flow distribution of the cooling medium within the flow channel, the formation of low-speed vortices in local areas, and ineffective heat transfer. On the other hand, when the included angle θ is greater than 60°, the boundary layer renewal frequency decreases, the wall thermal resistance increases, the formation of transverse secondary flow is suppressed, and the destructive ability of the thermal boundary layer is reduced. This leads to a decrease in heat transfer efficiency and may cause local overheating, increasing the risk of thermal failure. An excessively large included angle θ results in an overly strong guiding effect of the flow channel sidewalls, shortening the flow path of the cooling medium within the flow channel, reducing the opportunity for fluid mixing, and thus reducing heat transfer efficiency.

[0064] Regarding the control strategy for the channel wall thickness d, this invention achieves the optimal balance between mechanical properties and thermal management efficiency by establishing a quantitative relationship between wall thickness and structural parameters. Specifically, based on mechanical strength criteria, heat dissipation performance requirements, and fluid dynamics characteristics, the preferred range for wall thickness d is determined: d = 1.8 mm - 3.0 mm. In practical implementation, the wall thickness optimization design of this invention exhibits three significant technical features: First, by precisely controlling the wall thickness parameter, it not only effectively alleviates the problem of periodic thermal stress concentration during charge-discharge cycles but also achieves synergistic optimization of cooling efficiency and load-bearing capacity. Experimental data shows that the trapezoidal channel designed using this scheme maintains structural integrity after 100,000 charge-discharge cycles, while the traditional rectangular channel shows significant failure after 30,000 cycles. Second, a scientific wall thickness selection standard is established. When the channel wall thickness is less than the critical value of 1.8 mm, stress concentration will occur in local areas of the liquid cooling plate under maximum working pressure conditions, causing the actual working stress to exceed the allowable stress limit of the material, thereby triggering the risk of structural failure. When the channel wall thickness is within the preferred range of 1.8mm-3.0mm, the liquid cooling plate achieves the best balance between safety and economy. However, when the wall thickness exceeds the critical value of 3.0mm, although the structural strength is further improved, it leads to material waste and has limited practical engineering value. Simultaneously, excessively thick walls increase thermal resistance, hindering heat conduction and thus reducing the overall heat dissipation efficiency of the liquid cooling system. Thirdly, the preferred wall thickness range provided by this invention is compatible with current mainstream 280AH and 314AH square batteries, forming liquid-cooled battery packs capable of supporting 48, 52, and 104 cells, demonstrating wide applicability. This wall thickness design method based on quantitative analysis, verified through both finite element simulation (using Miner's linear cumulative damage theory) and physical testing, confirms that it can increase the fatigue life of the trapezoidal channel to three times that of traditional designs. More importantly, this solution not only resolves the contradiction between strength and heat dissipation but also significantly extends service life through stress optimization, providing a complete engineering solution for the efficient and reliable design of liquid cooling plates.

[0065] Based on the above analysis, the optimal structural parameters for the trapezoidal cross-section are:

[0066] The aspect ratio kb / a = 1.8 ± 0.2;

[0067] The height ratio mh / a = 1.4 ± 0.2;

[0068] Angle θ = 45° ± 15°;

[0069] The flow channel wall thickness d = 1.8mm-3.0mm.

[0070] By adopting the above technical solution:

[0071] By systematically optimizing and carefully adjusting multiple key parameters such as the cross-sectional shape and geometric dimensions of the flow channels, a uniform distribution of coolant was achieved as it flowed through the liquid cooling plate. This uniform flow velocity distribution effectively avoids the phenomenon of excessively fast or slow local coolant flow velocities common in traditional designs, thus ensuring uniform and efficient cooling of the battery module during charging and discharging. The flow channel design significantly improved the flow characteristics of the coolant by optimizing the cross-sectional shape. For example, the trapezoidal cross-section design not only improved the structural strength of the flow channel but also enhanced the disturbance effect of the thermal boundary layer by inducing secondary flow phenomena (such as Dean vortices), thereby improving heat transfer efficiency. Simultaneously, precise control of the flow channel dimensions effectively reduced pressure drop losses during coolant flow, further improving the system's energy efficiency ratio.

[0072] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A battery pack liquid cooling plate structure based on a trapezoidal cross-section flow channel, characterized in that: The system includes a liquid cooling plate body (1), which has a plurality of trapezoidal flow channels that are connected end to end. The width-to-height ratio b / a of the trapezoidal flow channels is 1.6 to 2.0; the height ratio h / a of the trapezoidal flow channels is 1.2 to 1.6; the angle θ between the side wall and the bottom of the trapezoidal flow channels is 30° to 60°; and the wall thickness d of the trapezoidal flow channels is 1.8 mm to 3.0 mm. Where a is the width of the upper base of the trapezoidal flow channel, b is the width of the lower base of the trapezoidal flow channel, h is the height of the trapezoidal flow channel, d is the wall thickness of the trapezoidal flow channel, and θ is the angle between the side wall and the lower base of the trapezoidal flow channel.

2. The battery pack liquid cooling plate structure based on a trapezoidal cross-section flow channel as described in claim 1, characterized in that: The liquid cooling plate body (1) is made of high-strength aluminum alloy through precision extrusion process. The trapezoidal flow channel runs through its front and rear ends, and several trapezoidal flow channels are connected end to end in sequence to form a continuous coolant circulation channel. The inner wall surface of the trapezoidal flow channel is smooth.

3. The battery pack liquid cooling plate structure based on a trapezoidal cross-section flow channel as described in claim 1, characterized in that: The liquid cooling plate body (1) is provided with side beams (2) on both the left and right sides. The liquid cooling plate body (1) is provided with front beam (3) and rear beam (4) on the front and rear sides respectively. The front beam (3) is provided with two water nozzles (6), and the two water nozzles (6) are respectively connected to the trapezoidal flow channels on the two outer sides of the liquid cooling plate body (1).

4. The battery pack liquid cooling plate structure based on a trapezoidal cross-section flow channel as described in claim 3, characterized in that: The liquid cooling plate body (1) is provided with several middle beams (5) on both the upper and lower sides for fixing the liquid cooling plate structure body.

5. The battery pack liquid cooling plate structure based on a trapezoidal cross-section flow channel as described in claim 1, characterized in that: The liquid cooling plate body (1) has a front sealing block (7) and a rear sealing block (8) at the bottom front and rear ends respectively. The front sealing block (7) has two water nozzles (6), which are connected to the trapezoidal flow channels on the two outer sides of the liquid cooling plate body (1).

6. The battery pack liquid cooling plate structure based on a trapezoidal cross-section flow channel as described in claim 5, characterized in that: The liquid cooling plate body (1) has several load-bearing base supports (9) parallel to the front sealing block (7) at the bottom, and several crossbeams (10) parallel to the front sealing block (7) at the top. Both the load-bearing base supports (9) and the crossbeams (10) adopt an embedded structure.

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