Battery pack liquid cooling plate structure based on trapezoidal cross-section runner

Abstract

The battery pack liquid cooling plate structure comprises a liquid cooling plate main body, the liquid cooling plate main body is internally provided with a plurality of trapezoidal flow channels which are sequentially communicated end to end, and the aspect ratio b / a of the trapezoidal flow channels is 1.6-2.0; the height ratio h / a of the trapezoidal runner is 1.2-1.6; the included angle theta between the side wall and the lower bottom of the trapezoidal runner is 30-60 degrees; the flow channel wall thickness d of the trapezoidal flow channel is 1.8 mm-3. 0mm. The heat exchanger relates to the technical field of new energy power battery heat management, adopts the design of the trapezoidal cross-section flow channel, and improves the maximum bearing capacity, the heat dissipation efficiency and the temperature uniformity by optimizing the aspect ratio, the height ratio, the included angle, the flow channel wall thickness and other parameters. The divergent section configuration of the trapezoidal flow channel can induce the secondary flow phenomenon, enhance the disturbance of a thermal boundary layer and improve the heat transfer efficiency. Meanwhile, according to the design, the friction resistance is reduced by optimizing the aspect ratio, the turbulence energy is regulated and controlled through the height ratio, and the pressure drop and heat transfer performance are effectively balanced.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy power battery thermal management, and specifically relates to a liquid cooling plate structure for a battery pack based on a trapezoidal cross-section flow channel. Background Technique

[0002] With the continuous improvement of the energy density of power batteries, the heat dissipation performance of the battery thermal management system has become the core factor restricting the safety and service life of the battery pack. Traditional liquid cooling plates mostly adopt rectangular cross-section flow channel designs. The uneven distribution of the coolant flow velocity in them easily leads to local overheating of the battery module. At the same time, the flow separation phenomenon caused by the sudden change of the rectangular flow channel cross-section will significantly increase the pressure drop loss and energy consumption. In the prior art, key parameters such as the aspect ratio and height ratio of the flow channel lack systematic optimization. Often, due to the excessive pursuit of the heat transfer area, the flow velocity attenuation and the convective heat transfer coefficient decrease, and the conventional structure is difficult to balance the contradictory relationship between the heat dissipation efficiency and the pressure drop loss. At the manufacturing process level, the traditional welded flow channel has the risk of weld defects, and the problem of prominent die stress concentration during the extrusion forming of the rectangular flow channel leads to a low yield rate and insufficient die life. In addition, existing liquid cooling plates generally face the problem of fatigue failure caused by thermal stress concentration, and structural cracks and seal failures are likely to occur during long-term charge and discharge cycles. In view of the above technical bottlenecks, there is an urgent need to develop a new liquid cooling plate flow channel design scheme with both high heat transfer characteristics, excellent structural reliability and process adaptability to meet the stringent heat dissipation requirements of high-power density battery modules and reduce the full-life cycle usage cost. Summary of the Invention

[0003] The purpose of the present invention is to provide a liquid cooling plate structure for a battery pack based on a trapezoidal cross-section flow channel to solve the problems raised in the above background technique.

[0004] The technical solution adopted by the present invention is as follows:

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

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

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

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

[0009] Preferably, a plurality of middle beams are provided on both the upper and lower sides of the liquid cooling plate body for fixing the main body of the liquid cooling plate structure.

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

[0011] Preferably, a plurality of load-bearing bottom supports parallel to the front sealing block are provided at the bottom of the liquid cooling plate body, and a plurality of cross beams parallel to the front sealing block are provided at the top of the liquid cooling plate body, and both the load-bearing bottom supports and the cross beams adopt an embedded structure.

[0012] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows:

[0013] In the present invention, a trapezoidal cross-section flow channel design is adopted. By optimizing parameters such as the width-to-height ratio, height ratio, included angle, and flow channel wall thickness, the maximum load-bearing capacity, heat dissipation efficiency, and temperature uniformity are improved. The gradually expanding cross-section configuration of the trapezoidal flow channel can induce secondary flow phenomena, enhance the disturbance of the thermal boundary layer, and improve the heat transfer efficiency. At the same time, this design reduces the frictional resistance through the optimization of the width-to-height ratio and regulates the turbulent kinetic energy through the height ratio, effectively balancing the pressure drop and heat transfer performance. In addition, the cross-section moment of inertia characteristics of the trapezoidal cross-section disperse the periodic thermal load, improving the load-bearing capacity and structural strength. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0015] Figure 2 It is a schematic diagram of a first liquid cooling plate structure of the present invention;

[0016] Figure 3 It is a cross-sectional view of a first liquid cooling plate structure of the present invention;

[0017] Figure 4 It is a schematic diagram of another form of a first liquid cooling plate structure of the present invention;

[0018] Figure 5 It is a schematic diagram of a second liquid cooling plate structure of the present invention;

[0019] Figure 6 It is a cross-sectional view of a second liquid cooling plate structure of the present invention;

[0020] In the figure: 1. Liquid cooling plate main body; 2. Side beam; 3. Front beam; 4. Rear beam; 5. Middle beam; 6. Water nozzle; 7. Front plugging block; 8. Rear plugging block; 9. Load-bearing bottom bracket; 10. Cross beam. Detailed implementation manners

[0021] The following details the specific implementation manners of the present invention.

[0022] The "range" disclosed in the present invention is defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a specific range. The range defined in this way can include the end values or not include the end values, and can be combined arbitrarily, 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, ranges of 10-40 and 20-50 are also anticipated. In addition, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4, and 5 are listed, the following ranges are all anticipated: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise specified, the numerical range "a-b" represents an abbreviated representation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been fully listed in this article, and "0-5" is only an abbreviated representation of these numerical combinations.

[0023] If there is no special indication, all implementation manners and optional implementation manners of this application can be combined with each other to form a new technical solution.

[0024] If there is no special indication, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0025] If there is no special indication, all steps of this application can be carried out in sequence or randomly, and preferably in sequence. For example, the method includes steps (a) and (b), which means that the method can include steps (a) and (b) carried out in sequence, or can also include steps (b) and (a) carried out in sequence. For example, it is mentioned that the method may further include step (c), which means that step (c) can be added to the method in any order. For example, the method can include steps (a), (b), and (c), or can also include steps (a), (c), and (b), or can also include steps (c), (a), and (b), etc.

[0026] If there is no special indication, the "including" and "comprising" mentioned in this application mean open-ended or can also be closed-ended. For example, the "including" and "comprising" can mean that other components not listed can also be included or comprised, or can only include or comprise the listed components.

[0027] Unless otherwise specified, the reaction is carried out under normal temperature and pressure conditions.

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

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

[0030] In the present invention, the devices or equipment used are all conventional devices or equipment known in the field and can be purchased.

[0031] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0032] Example 1:

[0033] A liquid cooling plate structure for a battery pack based on a trapezoidal cross-section flow channel, as Figure 1 shown, includes a liquid cooling plate main body 1. A number of trapezoidal flow channels that are sequentially connected end to end are provided inside the liquid cooling plate main body 1. The aspect ratio b / a of the trapezoidal flow channel is 1.6 to 2.0; the height ratio h / a of the trapezoidal flow channel is 1.2 to 1.6; the angle θ between the side wall and the lower bottom of the trapezoidal flow channel is 30° to 60°; the wall thickness d of the trapezoidal flow channel is 1.8 mm to 3.0 mm;

[0034] Wherein, a is the width of the upper bottom of the trapezoidal flow channel, b is the width of the lower bottom 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 bottom of the trapezoidal flow channel.

[0035] In a possible implementation manner, the aspect 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 side wall and the lower bottom of the trapezoidal flow channel is 30°; the wall thickness d of the trapezoidal flow channel is 1.8 mm;

[0036] In a possible implementation manner, the aspect 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 side wall and the lower bottom of the trapezoidal flow channel is 50°; the wall thickness d of the trapezoidal flow channel is 2.9 mm;

[0037] In a possible implementation manner, the aspect 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 side wall and the lower bottom of the trapezoidal flow channel is 60°; the wall thickness d of the trapezoidal flow channel is 3.0 mm.

[0038] In a possible implementation, the liquid cooling plate body 1 is formed by precision extrusion of high-strength aluminum alloy. The trapezoidal flow channels penetrate through its front and rear ends, and several trapezoidal flow channels are connected end to end in sequence to form a continuously penetrating coolant circulation flow channel, and the inner wall surface of the trapezoidal flow channel is smooth.

[0039] In a possible implementation, side beams 2 are provided on both the left and right sides of the liquid cooling plate body 1, a front beam 3 and a rear beam 4 are respectively provided on the front and rear sides of the liquid cooling plate body 1, and two water nozzles 6 are provided on the front beam 3. 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 middle beams 5 are provided on both the upper and lower sides of the liquid cooling plate body 1 for fixing the main structure of the liquid cooling plate.

[0041] In a possible implementation, a front plug block 7 and a rear plug block 8 are respectively provided at the front and rear ends of the bottom of the liquid cooling plate body 1. Two water nozzles 6 are provided on the front plug block 7. 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.

[0042] Furthermore, several load-bearing bottom supports 9 parallel to the front plug block 7 are provided at the bottom of the liquid cooling plate body 1, and several cross beams 10 parallel to the front plug block 7 are provided at the top of the liquid cooling plate body 1. Both the load-bearing bottom supports 9 and the cross beams 10 adopt an embedded structure.

[0043] Example 2:

[0044] A liquid cooling plate structure, the liquid cooling plate includes a liquid cooling plate body 1, side beams 2, water nozzles 6, a front beam 3, a rear beam 4 and middle beams 5, as Figure 2 shown. The illustrated liquid cooling plate is applicable to a 48 / 52 cell battery pack. Among them, the water nozzles 6 are formed by precision machining technology, ensuring the dimensional accuracy and shape accuracy of each component of the water nozzles 6. The main flow channel 5 is formed by precision extrusion of high-strength aluminum alloy profiles, and a continuously penetrating coolant circulation flow channel is formed inside. As Figure 3As shown, the cross-section of the liquid cooling plate flow channel adopts a trapezoidal design. The trapezoidal cross-section parameters satisfy the width-to-height ratio b / a = 1.8 ± 0.2, the height ratio h / a = 1.4 ± 0.2, the included angle θ = 45° ± 15°, and the wall thickness of the flow channel satisfies d = 1.8 mm - 3.0 mm. This structure has been optimized by fluid mechanics, which can significantly reduce the pressure drop loss during the coolant flow while ensuring high-efficiency heat transfer performance. The front beam 3, the rear beam 4, and the middle beam 5 are all made by secondary processing of profiles. Their cross-sectional shapes are specially designed, which not only ensures the machining accuracy of the components but also effectively reduces the production cost and improves the production efficiency. In addition, the liquid cooling plate body 1, the side beam 2, the water nozzle 6, the front beam 3, the rear beam 4, and the middle beam 5 are welded and connected by TIG welding process, thus ensuring the mechanical strength, sealing performance, and reliability of the overall structure of the liquid cooling plate. The battery module is fixed between the rear beam 4 and the middle beam 5 by bolt connection. At the same time, the number of cells can also be adapted by adjusting the extrusion length of the profile 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, the middle beam 5, and the rear beam 4 are optimized, which not only improves the overall stiffness and strength of the structure but also reduces the material usage, thus reducing the production cost.

[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 the fields of electric vehicles, energy storage systems, etc. with broad application prospects. As Figure 4 shown, the structure of the liquid cooling plate of this embodiment can flexibly adapt to different specifications and numbers of cells by adjusting the extrusion length of the profile of the liquid cooling plate body 1 and 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 requirements. In addition, the application of the TIG welding process ensures the sealing and reliability of the overall structure of the liquid cooling plate, and it can maintain 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 has high structural strength and reliability, and is suitable for the cooling requirements of various high-power density battery modules.

[0046] As Figure 1As shown, the main flow channel of this embodiment adopts a trapezoidal structure design, specifically manifested as a gradually expanding cross-sectional configuration, where the bottom width b is greater than the top width a. This design significantly improves the distribution uniformity of the cooling medium in the flow channel, effectively inhibits the formation of local flow dead zones, and thus enhances the 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 perturbation effect of the thermal boundary layer but also significantly improves the heat transfer efficiency. The trapezoidal inclined plane configuration design of this embodiment effectively inhibits the flow separation phenomenon and avoids the flow instability problem caused by sudden cross-sectional changes in traditional flow channels. By optimizing the cross-sectional parameters of the flow channel to match the characteristics of dynamic working conditions, this embodiment ensures a stable linear correspondence relationship between the flow velocity and the heat transfer efficiency. This design fundamentally avoids the pressure oscillation problem that is prone to occur in traditional variable cross-section flow channels under sudden flow rate change conditions, thereby improving the stability and reliability of the system. Specifically, the trapezoidal flow channel design of this embodiment achieves performance optimization through the following mechanisms: First, the gradually expanding cross-sectional configuration makes the flow of the cooling medium in the flow channel more uniform, reducing the formation of local high-temperature regions; Second, the secondary flow phenomenon induced by the inclined sidewalls enhances the mixing effect of the fluid, further improving the heat transfer efficiency; Finally, the design of constant cross-sectional parameters ensures the linear relationship between the flow velocity and the heat transfer efficiency under different working conditions, avoiding the pressure fluctuations and energy losses generated by traditional variable cross-section flow channels during sudden flow rate changes. The trapezoidal flow channel design of this embodiment, through the gradually expanding cross-sectional configuration, the secondary flow phenomenon induced by the inclined sidewalls, and the optimization of constant cross-sectional parameters, not only significantly improves the heat transfer efficiency and flow uniformity but also effectively reduces the friction resistance and pressure oscillation, having important engineering application value and market promotion potential.

[0047] In terms of structural reliability, the trapezoidal cross-section design adopted in this embodiment has significant mechanical advantages. The cross-sectional moment of inertia characteristics of the trapezoidal cross-section are superior to those of the traditional rectangular structure, and it can effectively disperse the periodic thermal loads generated during the charge and discharge cycles of the battery pack. At the same time, the local stress peak of the trapezoidal cross-section structure is reduced by 30%-40% compared with the rectangular structure, thus significantly improving the fatigue resistance performance and the reliability of long-term use of the structure. At the same time, the main flow channel 5 is made by the high-strength aluminum alloy extrusion forming process, which ensures the integrity and consistency of the inner wall of the flow channel and avoids the weld or joint defects commonly found in traditional welded structures. Experimental data shows that the fatigue life of the flow channel structure using the single extrusion forming process is increased by more than 3 times compared with the traditional welded structure, and it can meet the reliability requirements of more than 100,000 charge and discharge cycles. This performance improvement is mainly due to the high-quality inner wall surface and uniform material distribution achieved by the single extrusion forming process, thus effectively reducing the risk of stress concentration and crack initiation. In addition, the trapezoidal cross-section design also has good anti-deformation ability and structural stability, and can withstand large thermal stresses and mechanical stresses during the charge and discharge process of the battery pack. Through the combination of the trapezoidal cross-section design and the single extrusion forming process, the present invention not only significantly reduces the local stress peak, but also greatly improves the fatigue life and reliability of the structure, and can meet the long-term use requirements under high-frequency charge and discharge cycles. This design has important practical significance in improving the overall performance and life of the battery module.

[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 the extrusion forming process. By optimizing the cross-sectional shape and size parameters of the flow channel, the complexity of the die structure is significantly reduced, and the die manufacturing and maintenance costs are greatly reduced. Data shows that by using the extrusion forming process, the single forming yield rate can be increased to more than 90%, which is about 20% higher than the traditional process. In addition, due to the extremely low material waste of the extrusion forming process, the material utilization rate is as high as 95%, while the material utilization rate of the traditional milling process is only about 60%, thus significantly reducing the raw material cost. Further, by adjusting the core parameters such as the upper base width a and the width-to-height ratio k in this embodiment, the different heat dissipation requirements of different types of battery modules can be flexibly adapted. This design can be compatible with square batteries, cylindrical batteries and soft-pack battery modules, covering more than 90% of the mainstream power battery specifications. For example, for square battery modules, the heat dissipation contact area can be enlarged by increasing the upper base width a; for cylindrical battery modules, the fitting degree between the flow channel and the battery surface can be optimized by adjusting the width-to-height ratio k; and for soft-pack battery modules, the cross-sectional shape can be finely adjusted to adapt to its flexible characteristics. This highly flexible design makes this embodiment have wide applicability in practical applications.

[0049] In terms of large-scale production, the structural design of this embodiment not only reduces the production cost of a single product but also significantly improves production efficiency. Due to the continuous production characteristics of the extrusion molding process, combined with the optimized design of this embodiment, efficient and stable mass production can be achieved. According to actual production data, for the liquid cooling plate designed in this embodiment, the large-scale production cost is reduced by about 30% compared with the traditional process, and the production cycle is shortened by more than 25%. These advantages make this embodiment have significant economic benefits and market competitiveness in industrial applications. At the engineering implementation level, this embodiment not only improves production efficiency and product yield by optimizing the structural design and process parameters but also greatly reduces material waste and production costs. Its flexible design parameters enable this liquid cooling plate to adapt to various types of battery modules, covering the vast majority of mainstream power battery specifications, and have significant industrial application value and market promotion potential.

[0050] Embodiment 3:

[0051] As Figure 5 shown, this embodiment provides a highly efficient integrated liquid cooling plate structure, including a liquid cooling plate main body 1, cross beams 10, water nozzles 6, a front plugging block 7, a rear plugging block 8, and a load-bearing bottom support 9. As Figure 6 shown, the internal cross-section of the liquid cooling plate profile adopts a trapezoidal structure design, and the trapezoidal cross-section parameters meet: width-to-height ratio b / a = 1.8 ± 0.2, height ratio h / a = 1.4 ± 0.2, included angle θ = 45° ± 15°, and the 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, and at the same time, the pressure drop in the flow channel is effectively reduced, ensuring uniform distribution of the coolant in the flow channel and avoiding local overheating. The two cross beams are arranged on the front of the liquid cooling plate profile in an embedded manner and are firmly connected to the liquid cooling plate profile through the welding process, enhancing the rigidity and anti-deformation ability of the overall structure, enabling it to remain stable when bearing external loads, and avoiding deformation or damage caused by vibration or impact. The inlet and outlet water nozzles are directly connected to the internal flow channel of the liquid cooling plate and are fixed by welding, ensuring efficient input and output of the coolant, improving the sealing performance and reliability of the connection part at the same time, and preventing coolant leakage under high-pressure conditions. The front plugging block and the rear plugging block are respectively arranged at both ends of the liquid cooling plate. Through precision machining and assembly, the connection and sealing of the internal flow channel are realized, forming a complete sealed liquid cooling circuit, effectively preventing coolant leakage, and ensuring the circulation efficiency of the coolant in the flow channel. The three parallel distributed load-bearing bottom supports are installed at the bottom of the liquid cooling plate, made of high-strength materials. By optimizing the distribution position and fixing method, the load-bearing performance and stability of the liquid cooling plate are significantly improved, enabling it to bear greater external loads, and reducing fatigue damage caused by long-term use.

[0052] Through integrated design and modular assembly, this embodiment simplifies the production process, shortens the production period, effectively reduces the manufacturing cost, and at the same time improves the overall performance and service life of the liquid cooling plate. In addition, the structural design of this embodiment also fully considers the assembly convenience and maintenance convenience, 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 applicable to the high-efficiency thermal management requirements in the fields of new energy vehicles, energy storage systems, and industrial equipment, and can effectively solve the problems of complex structure, high cost, and insufficient load-bearing performance of traditional liquid cooling plates, with broad application prospects and market value. Through actual test verification, the liquid cooling plate of this embodiment is superior to the traditional design in terms of thermal management performance, structural strength, and service life, and can meet the thermal management requirements of high reliability, high efficiency, and high stability. Through actual test verification, the liquid cooling plate of this embodiment is superior to the traditional design in terms of thermal management performance, structural strength, and service life, and can meet the thermal management requirements of high reliability, high efficiency, and high stability.

[0053] Embodiment 4:

[0054] A battery pack liquid cooling plate structure capable of achieving uniform flow distribution, including a main flow channel profile, a water nozzle, and a cross beam required for fixing the battery; the cross section of the flow channel satisfies the following geometric parameter definitions:

[0055] Upper bottom width: a (2.5 - 6.5)

[0056] Lower bottom width: b = k·a (k = 1.6 - 2.0)

[0057] Flow channel height: h = m·a (m = 1.2 - 1.6)

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

[0059] Angle: θ = 45° ± 15°

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

[0061] In terms of the optimization of the aspect ratio (k = b / a) parameter, 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, the increase in the aspect ratio k enlarges the contact area between the flow channel and the battery module, enhances the heat conduction effect, and at the same time optimizes the flow distribution of the cooling medium, enabling heat to be transferred and dissipated more evenly. However, when the aspect ratio k exceeds the threshold, the increase in the cross-sectional equivalent diameter will cause the flow velocity of the cooling medium to show a linear decay trend, and at the same time trigger a decrease in the convective heat transfer coefficient, thereby weakening the overall heat dissipation performance. Further, from the perspective of the adaptability of the forming process, when the upper limit of the aspect ratio k is set to 2.0, the stress concentration coefficient of the extrusion die can be controlled within a safe and reasonable range (usually less than 1.5), thereby effectively extending the service life of the die and improving production efficiency. At the same time, this limitation also helps to ensure the forming quality and dimensional accuracy, avoiding deformation, cracking or other defects caused by excessive die stress, and ensuring the consistency and reliability of the product.

[0062] For the optimization of the height ratio (m = h / a) parameter, experimental data shows that when the height ratio m is in the range of 1.2 - 1.6, the increase in the flow channel height can significantly increase the turbulent kinetic energy of the coolant, while reducing the vortex scale in the near-wall region and the thickness of the thermal boundary layer, thereby significantly improving the temperature uniformity and heat transfer efficiency of the liquid cooling plate. The increase in the flow channel height enhances the flow perturbation effect of the cooling medium, promotes the destruction and renewal of the thermal boundary layer, and enables heat to be transferred from the battery module to the cooling medium more efficiently. When the height ratio m exceeds 2.0, the non-linear growth of the wetted perimeter will cause a sharp increase in the frictional resistance, resulting in a significant increase in the pressure drop rate exceeding the improvement amplitude of the heat transfer performance. This phenomenon will not only deteriorate the flow stability of the liquid cooling plate, but also accelerate the fatigue failure of the flow channel, reducing the reliability and service life of the system. The excessive increase in the height ratio m will cause a significant increase in the contact area between the inner wall surface of the flow channel and the cooling medium, thereby significantly increasing the flow resistance.

[0063] In the control strategy of the included angle θ parameter, when the included angle θ is in the range of 30° - 60°, the tapered structure of the trapezoidal sidewall can significantly enhance the intensity of the transverse secondary flow and improve the fluid mixing efficiency. This design enables the cooling medium to form stronger vortex disturbances in the flow channel, thereby enhancing the ability to disrupt and renew the thermal boundary layer. The optimized design of the included angle θ achieves a refined balance between pressure drop and energy consumption, while significantly improving the heat dissipation efficiency and temperature uniformity. However, when the included angle θ is less than 30°, the flow separation phenomenon will intensify, resulting in an increase in the area of the low-speed vortex region, and then causing a sharp increase in the local pressure drop. This phenomenon will form a dead zone effect, resulting in a significant decrease in the heat transfer efficiency, and at the same time leading to an imbalance between pressure drop and energy consumption and deterioration of temperature uniformity. If the included angle θ is too small, the guiding effect of the flow channel sidewall will be weakened, the flow distribution of the cooling medium in the flow channel will be uneven, and low-speed vortices will form in local areas, resulting in 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 the transverse secondary flow is inhibited, and the ability to disrupt the thermal boundary layer is reduced. This will lead to a decline in the heat transfer efficiency and may cause local overheating, increasing the risk of thermal failure. If the included angle θ is too large, the guiding effect of the flow channel sidewall will be too strong, the flow path of the cooling medium in the flow channel will be shortened, reducing the opportunity for fluid mixing, thereby reducing the heat transfer efficiency.

[0064] For the regulation strategy of the wall thickness d of the flow channel, the present invention realizes the best balance between mechanical properties and thermal management efficiency by establishing a quantitative relationship between the wall thickness and structural parameters. Specifically, first, based on the mechanical strength criterion, heat dissipation performance requirements, and fluid dynamics characteristics, the preferred range of the wall thickness d is determined: d = 1.8 mm - 3.0 mm. In the specific implementation process, the wall thickness optimization design of the present invention exhibits three significant technical features: First, by precisely controlling the wall thickness parameters, not only the problem of periodic thermal stress concentration during charge and discharge cycles is effectively alleviated, but also the collaborative optimization of cooling efficiency and load-bearing performance is achieved. Experimental data shows that the trapezoidal flow channel designed by this scheme still maintains its structural integrity after 100,000 charge and discharge cycles, while the traditional rectangular flow channel shows obvious failure after 30,000 cycles. Second, a scientific wall thickness selection criterion is established. When the wall thickness of the flow channel is less than the critical value of 1.8 mm, under the maximum working pressure condition, stress concentration will occur in the local area of the liquid cooling plate, resulting in the actual working stress exceeding the allowable stress limit of the material, thus triggering the risk of structural failure. When the wall thickness of the flow channel is within the preferred range of 1.8 mm - 3.0 mm, the liquid cooling plate can obtain the best balance between safety performance and economy; when the wall thickness is greater than the critical value of 3.0 mm, although the structural strength is further improved, it will cause material waste and the actual engineering value is limited. At the same time, an overly thick wall surface will increase the thermal resistance and hinder heat conduction, thereby reducing the overall heat dissipation efficiency of the liquid cooling system. Third, the preferred wall thickness range provided by the present invention is adapted to the current mainstream 280AH and 314AH square batteries, and can form liquid cooling plate battery packs that can carry 48, 52, and 104 battery cells, showing wide applicability. This wall thickness design method based on quantitative analysis is verified by both finite element simulation (using Miner's linear cumulative damage theory) and physical testing, and it is confirmed that the fatigue life of the trapezoidal flow channel can be increased to 3 times that of the traditional design. More importantly, this scheme not only solves the contradiction between strength and heat dissipation, but also significantly extends the service life through stress optimization, providing a complete engineering technical solution for the efficient and reliable design of liquid cooling plates.

[0065] Through the above analysis, the optimal structural parameters of the trapezoidal cross-section are:

[0066]

[0067] By adopting the above technical solutions:

[0068] Through systematic optimization and careful adjustment of multiple key parameters such as the cross-sectional shape and geometric dimensions of the flow channels, uniform distribution of the coolant during its flow through the liquid cooling plate is achieved. This uniform flow velocity distribution effectively avoids the phenomena of excessively fast or slow local coolant flow velocities commonly seen in traditional designs, thereby ensuring that the battery module can obtain uniform and efficient cooling during the charging and discharging processes. The flow channel design significantly improves the flow characteristics of the coolant by optimizing the cross-sectional shape of the flow channels. For example, the trapezoidal cross-sectional design not only enhances the structural strength of the flow channels but also enhances the perturbation effect of the thermal boundary layer by inducing secondary flow phenomena (such as Dean vortices), thereby improving the heat transfer efficiency. At the same time, through precise control of the flow channel dimensions, the pressure drop loss during the coolant flow is effectively reduced, further improving the energy efficiency ratio of the system.

[0069] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A liquid cooling plate structure for a battery pack based on a trapezoidal cross-section flow channel, characterized in that: It includes a liquid cooling plate body (1). Inside the liquid cooling plate body (1), there are several trapezoidal flow channels that are successively connected end to end. The aspect ratio b / a of the trapezoidal flow channel is 1.6 - 2.0; the height ratio h / a of the trapezoidal flow channel is 1.2 - 1.6; the included angle θ between the side wall and the bottom of the trapezoidal flow channel is 30° - 60°; the wall thickness d of the trapezoidal flow channel is 1.8 mm - 3.0 mm. Among them, 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 included angle between the side wall and the bottom of the trapezoidal flow channel.

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

3. The liquid cooling plate structure of a battery pack based on a trapezoidal cross-section flow channel according to claim 1, wherein: On both the left and right sides of the liquid cooling plate body (1), there are side beams (2). On the front and rear sides of the liquid cooling plate body (1), there are a front beam (3) and a rear beam (4) respectively. On the front beam (3), there are two nozzles (6), and the two nozzles (6) are respectively connected to the trapezoidal flow channels on the two outer sides of the liquid cooling plate body (1).

4. The liquid cooling plate structure of a battery pack based on a trapezoidal cross-section flow channel as described in claim 3, wherein: On both the upper and lower sides of the liquid cooling plate body (1), there are several middle beams (5) for fixing the main structure of the liquid cooling plate.

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

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

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