Corrugated power battery liquid cooling plate structure optimization design method

Abstract

The invention discloses a corrugated power battery liquid cooling plate structure optimization design method, which comprises the following steps: constructing a three-dimensional model of a battery liquid cooling plate connected with a battery module through a heat conduction pad, obtaining related structure parameters of the model, and determining variable parameters to be optimized; establishing a multi-objective optimization calculation model; carrying out simulation analysis on the three-dimensional model, and calculating to obtain performance data of the battery liquid cooling plate with a corresponding value; and a Pareto solution set of multi-objective optimization is obtained, an optimal solution is searched in the Pareto frontier solution set, and the optimal value of each structure parameter is obtained. The method has the beneficial effects that the method analyzes the influence of different structure parameters on a plurality of evaluation indexes through the combination of the fine design of the structure parameters and the multi-objective optimization algorithm, and determines the required optimal optimization scheme structure parameter combination, and the finally obtained optimization scheme is small in pressure drop change, can eliminate the heat dissipation dead angle, and can improve the heat dissipation efficiency. Uniform flow distribution of each runner is ensured, and the heat exchange capability is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of battery thermal management, and particularly relates to an optimized design method for the structure of a corrugated power battery liquid cooling plate. Background Art

[0002] With the continuous development of electric vehicles, as the main energy source, the performance, endurance, and safety of power batteries have attracted more and more attention from people and the market. In order to ensure the stable output, long-term endurance, and lifespan of power batteries, it is very important to promptly remove a large amount of waste heat generated during the charging or operation of power batteries. There are relatively high requirements for the ideal operating temperature range of power batteries. Taking lithium-ion batteries, which are most favored by the market, as an example, their optimal operating temperature range is 20°C to 40°C, and the temperature difference between batteries does not exceed 5°C. Therefore, a suitable cooling system is needed to ensure and improve the performance, lifespan, and safety of power batteries, preventing a large amount of waste heat generated by power batteries from not being dissipated in time, resulting in too high battery temperatures, accelerating the attenuation of battery materials, reducing the cycle life and safety of batteries, and even causing thermal runaway and combustion accidents.

[0003] Currently, common cooling methods include air cooling, liquid cooling, and phase change material cooling. Although air cooling has advantages such as low cost, flexible space layout, and light weight, as the demand for battery charging and discharging power continues to rise, the heat dissipation capacity of air cooling gradually becomes difficult to meet actual needs. Although phase change material cooling can achieve a relatively high cooling efficiency in a limited space, its long-term stable heat dissipation capacity is not high. Under high heat dissipation pressure, once the phase change material reaches the thermal saturation state, its heat dissipation capacity will be greatly reduced and cannot meet subsequent heat dissipation requirements. In contrast, liquid cooling can achieve a good balance in terms of performance, energy consumption, cost, safety, functionality, and compatibility, and is therefore widely used in the cooling systems of power batteries.

[0004] However, as the core component of liquid cooling, the liquid cooling plate is usually designed as a simple parallel direct flow channel or a serpentine flow channel. On the one hand, in this conventional design, it is difficult to effectively cover the edge areas of the cooling part, resulting in dead corners in heat dissipation; on the other hand, it is prone to the problem of uneven flow distribution, which in turn leads to conditions such as local overheating of the battery, low heat dissipation efficiency, and uneven heat dissipation, seriously affecting the performance, lifespan, and safety of power batteries. Summary of the Invention

[0005] The purpose of the present invention is to provide an optimized design method for the structure of a corrugated power battery liquid cooling plate in view of the deficiencies of the prior art, aiming to solve the problems of dead corners in heat dissipation and uneven flow distribution existing in the prior art.

[0006] The technical solution adopted by the present invention is as follows: An optimized design method for the corrugated power battery liquid cooling plate structure. The method includes the following steps: constructing a three-dimensional model in which the battery liquid cooling plate is connected to the battery module through a heat conduction pad, obtaining relevant structural parameters of the model, and determining the variable parameters to be optimized; taking maximizing the heat transfer coefficient of the cold plate and minimizing the pressure drop at the inlet and outlet of the cold plate as the optimization objectives, and taking the temperature difference of the heat transfer surface as the constraint condition to establish a multi-objective optimization calculation model; performing simulation analysis on the three-dimensional model under different values of the variable parameters, and combining with the multi-objective optimization calculation model to calculate the performance data of the battery liquid cooling plate corresponding to the corresponding values, including the heat transfer coefficient and the pressure drop; analyzing the performance data of the liquid cooling plate to obtain the Pareto solution set of multi-objective optimization, and selecting the Pareto front solution set; introducing a comprehensive evaluation score to find the optimal solution in the Pareto front solution set and obtain the best values of each variable parameter.

[0007] According to the above solution, the battery liquid cooling plate includes a stamping plate and a bottom plate. Liquid inlets and outlets are respectively arranged at both ends of the stamping plate, and a plurality of downward grooves are arranged on the stamping plate between the liquid inlets and outlets; the stamping plate is stacked on the bottom plate, and the bottom of the groove of the stamping plate is fixedly connected to the upper surface of the bottom plate. A coolant flow area is formed between the stamping plate and the bottom plate. One end of the coolant flow area is an inlet area communicated with the liquid inlet on the stamping plate, and the other end of the coolant flow area is an outlet area communicated with the liquid outlet on the stamping plate; the grooves divide the coolant flow area into a plurality of flow channels, and both ends of each flow channel are communicated with the inlet area and the outlet area respectively; Along the direction from the inlet area to the outlet area, the grooves are divided into a groove front section, a groove middle section and a groove rear section that are successively connected end to end; the groove middle section is in a corrugated shape; the groove rear section and the groove front section are symmetrically arranged at both ends of the groove middle section; each groove front section is symmetrically arranged with the inlet area as the center, and each groove middle section is arranged in parallel with each other.

[0008] According to the above solution, the corrugated shape of each groove middle section is consistent with the image of a trigonometric function; taking the center of the stamping plate as the origin, taking the width direction of the stamping plate as the Y direction, and taking the length direction of the stamping plate as the X direction to establish a coordinate system, then the corrugated shape of the groove middle section satisfies the following trigonometric function relation: (1); wherein, y is the Y-direction coordinate of the groove, with the unit of mm; x is the X-direction coordinate of the groove, with the unit of mm; A is the amplitude, with the unit of mm; λ is the wavelength, with the unit of mm; h i is the Y-direction distance from the i-th groove to the center of the stamping plate, with the unit of mm.

[0009] According to the above solution, the starting positions of each groove are all located on a circle with the foot of the perpendicular from the center of the liquid inlet on the edge of the stamping plate as the center and a radius of 80-90 mm.

[0010] According to the above - mentioned scheme, there are two liquid inlets. The starting position of the partial groove is set at the center of the lower liquid inlet, and the rest are symmetrically arranged with respect to the mid - line in the width direction of the stamping plate. The front section of the groove includes an arc section and a horizontal section. The starting position of the arc section is also the starting position of the front section of the groove. The end of the arc section is horizontally tangent to the starting point of the horizontal section, and the end of the horizontal section is horizontally connected to the starting point of the middle section of the groove.

[0011] According to the above - mentioned scheme, the first groove to the sixth groove are successively arranged on the stamping plate along the width direction; the multi - objective optimization calculation model is: (3); In the formula, represents the variable parameters to be optimized, where x 1 represents the incident angle of the first groove; x 2 is the incident angle of the second groove; x 3 is the incident angle of the third groove; x 4 is the distance between the third groove and the fourth groove, in mm; x 5 is the distance between the second groove and the third groove, in mm; x 6 is the distance between the first groove and the second groove, in mm; x 7 is the wave - peak height, in mm; x 8 is the wave - trough height; the unit is mm; DP represents the pressure drop between the inlet and the outlet, the unit is mbar; HTC represents the heat transfer coefficient, the unit ; represents the temperature difference of the heat transfer surface, the unit is ℃; limits the maximum temperature difference of the heat transfer surface.

[0012] According to the above - mentioned scheme, the method for simulating and analyzing the three - dimensional model under different values of the variable parameters is as follows: Import the three - dimensional model into Star - CCM +, then mesh it, set the boundary conditions, and combine the multi - objective optimization calculation model and the SHERPA hybrid adaptive algorithm to simulate and analyze the three - dimensional model under different values of the variable parameters, and calculate the corresponding data.

[0013] According to the above - mentioned scheme, the comprehensive evaluation score R is obtained from the following equation: (6); In the formula: is the comprehensive evaluation score, without unit; is the weight matrix, L 1 、L 2 、L 3 are the weight coefficients of the pressure drop, the heat transfer coefficient, and the temperature difference of the heat transfer surface in sequence, without unit, L 1 、L 2 、L3 takes values of 0.5, 0.5, and 0 in sequence; is the normalized evaluation index matrix; are the corresponding indexes of pressure drop, heat transfer coefficient, and heat transfer surface temperature difference respectively, and the calculation formula is: (7); In formula (4), i i = 1, 2, 3, respectively represent the three corresponding indexes of pressure drop, heat transfer coefficient, and heat transfer surface temperature difference; is the value corresponding to the index; is the minimum value corresponding to the index; is the maximum value corresponding to the index.

[0014] According to the above scheme, the heat transfer coefficient HTC is calculated by the following formula: (4); In the formula refers to the heat source power, W; refers to the heat transfer surface area, m 2 ; , respectively represent the average temperature of the heat transfer surface and the average temperature of the fluid under the heat transfer surface, °C.

[0015] According to the above scheme, the pressure drop DP at the inlet and outlet of the battery liquid cooling plate is calculated by the following formula: (5); In the formula, , respectively represent the pressures at the inlet and outlet of the battery liquid cooling plate, mbar.

[0016] The beneficial effects of the present invention are as follows: The method of the present invention combines the refined design of structural parameters with a multi-objective optimization algorithm, analyzes the influence of different structural parameters such as channel width, corrugation amplitude, etc. on multiple evaluation indexes, and determines the combination of the best optimized scheme structural parameters by comparing the comprehensive evaluation scores, realizing the rapid and effective design of each structural parameter of the battery liquid cooling plate, shortening the design cycle, and improving the effectiveness of the design; the pressure drop of the finally obtained optimized scheme changes little, which can eliminate the heat dissipation dead angle, ensure uniform flow distribution in each channel, and improve the heat transfer capacity. Description of the Drawings

[0017] Figure 1 is the overall structural schematic diagram of Embodiment 1.

[0018] Figure 2 is the split schematic diagram of the stamping plate and the bottom plate in Embodiment 1.

[0019] Figure 3Schematic diagram of the positions of the grooves in Embodiment 1.

[0020] Figure 4 Schematic diagram of the grooves in Embodiment 1.

[0021] Figure 5 For Figure 4 Enlarged view of part C (showing relevant structural parameters).

[0022] Figure 6 Schematic diagram of the three-dimensional model constructed in Embodiment 2.

[0023] Figure 7 Exploded view of the three-dimensional model in Embodiment 2.

[0024] Figure 8 Pareto solution set and Pareto front solution set of multi-objective optimization in Embodiment 2 of this example.

[0025] Figure 9 Temperature nephogram of the heat transfer surface before and after optimization in Embodiment 2 of this example.

[0026] Figure 10 Comparison chart of pressure drop and heat transfer coefficient before and after optimization in Embodiment 2 of this example.

[0027] Wherein: 1. Stamping plate 1; 2. Groove; 2.1 to 2.6 are the first groove to the sixth groove in sequence; 2.7, front section 2.7 of the groove; 2.7.1, arc section; 2.7.2, horizontal section; 2.8, middle section of the groove; 2.9, rear section of the groove; 3. Bottom plate; 3.1, flow channel; 3.2, connection position between the groove and the bottom plate; 4. Thermal pad; 5. Battery module; 6. Liquid inlet; 7. Liquid outlet. Specific implementation method

[0028] In order to better understand the present invention, the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0029] A method for optimizing the design of a corrugated power battery liquid cooling plate structure, the method is as follows: construct a three-dimensional model in which the battery liquid cooling plate is connected to the battery module 5 through the thermal pad 4, obtain the relevant structural parameters of the model, and determine the variable parameters to be optimized; take maximizing the heat transfer coefficient of the battery liquid cooling plate and minimizing the pressure drop at the inlet and outlet of the battery liquid cooling plate as the optimization objectives, and take the temperature difference of the heat transfer surface as the constraint condition to establish a multi-objective optimization calculation model; perform simulation analysis on the three-dimensional model with different values of the variable parameters, and combine with the multi-objective optimization calculation model to calculate the performance data of the battery liquid cooling plate corresponding to the values, including the heat transfer coefficient and the pressure drop; analyze the performance data of the liquid cooling plate to obtain the Pareto solution set of multi-objective optimization, and select the Pareto front solution set; introduce a comprehensive evaluation score, find the optimal solution in the Pareto front solution set, and obtain the best values of each variable parameter.

[0030] As shown Figures 1-3 in the figure, a battery liquid cooling plate member, specifically a corrugated power battery liquid cooling plate member based on trigonometric functions, includes a stamping plate 1 and a bottom plate 3; Liquid inlet 6 and liquid outlet 7 are respectively arranged at both ends of the stamping plate 1; A plurality of downward grooves 2 are arranged on the stamping plate 1 between the liquid inlet 6 and the liquid outlet 7; The stamping plate 1 is stacked on the bottom plate 3, and the bottom of the groove 2 of the stamping plate 1 is fixedly connected to the upper surface of the bottom plate 3. A coolant flow area is formed between the stamping plate 1 and the bottom plate 3. One end of the coolant flow area is an inlet area communicating with the liquid inlet 6 on the stamping plate 1, and the other end of the coolant flow area is an outlet area communicating with the liquid outlet 7 on the stamping plate 1; The groove 2 divides the coolant flow area into a plurality of flow channels 3.1, and both ends of each flow channel 3.1 communicate with the inlet area and the outlet area respectively.

[0031] In the present invention, the connection position 3.2 between the groove 2 and the bottom plate 3 is as Figure 2 shown in the figure.

[0032] Preferably, as Figure 4 shown in the figure, along the direction from the inlet area to the outlet area, the groove 2 is divided into a groove front section 2.7, a groove middle section 2.8, and a groove rear section 2.9 that are connected end to end in sequence; the groove middle section 2.8 is in a corrugated shape; the groove rear section 2.9 and the groove front section 2.7 are symmetrically arranged at both ends of the groove middle section 2.8; each groove front section 2.7 is symmetrically arranged with the inlet area as the center, and each groove middle section 2.8 is arranged in parallel with each other.

[0033] Preferably, the corrugated shape of each groove middle section 2.8 is consistent with the image of the trigonometric function.

[0034] In the present invention, taking the center of the stamping plate 1 as the origin, taking the width direction of the stamping plate 1 as the Y direction, and taking the length direction of the stamping plate 1 as the X direction, a coordinate system is established. Then the corrugated shape of the groove middle section 2.8 satisfies the following trigonometric function relationship: (1); where y is the Y-direction coordinate of the groove 2, in mm; x is the X-direction coordinate of the groove 2, in mm; A is the amplitude, in mm; λ is the wavelength, in mm; h i is the Y-direction distance from the i-th groove to the center of the stamping plate 1, in mm. As Figure 3 shown in the figure, the first groove 2.1 to the sixth groove 2.6 are sequentially arranged along the width direction of the stamping plate 1, forming 7 flow channels 3.1.

[0035] Preferably, the ripple amplitude A of the middle section 2.8 of the groove is 0 to 30 mm, and the wavelength λ is 400 mm.

[0036] In the present invention, the middle sections 2.8 of the grooves are parallel to each other, and the middle sections 2.8 of the grooves on the width center of the stamping plate 1 (i.e., when x = 0) are simultaneously at the wave crest or at the wave trough; and at least one wave crest or wave trough appears in the middle sections 2.8 before and after the width center of the stamping plate 1, that is, each middle section 2.8 of the groove includes at least two wave crests and one wave trough, or at least two wave troughs and one wave crest.

[0037] As Figure 5 shown, the starting positions of the grooves 2 (i.e., the starting positions of the front sections 2.7 of the grooves) are all located on a circle with the foot of the perpendicular from the center of the liquid inlet 6 to the edge of the stamping plate 1 as the center and a radius of 80 to 90 mm (specifically, it can be 85 mm). As Figure 5 shown in, the incident angles of the first groove 2.1 to the third groove 2.3 (i.e., the angle between the line connecting the starting position and the center of the circle and the width direction of the stamping plate 1) are 15 to 30°, 30 to 60°, and 45 to 90° respectively. The fourth groove 2.4, the fifth groove 2.5, and the sixth groove 2.6 are symmetrically arranged with the third groove 2.3, the second groove 2.2, and the first groove 2.1 in sequence, that is, the incident angles of the fourth groove 2.4, the fifth groove 2.5, and the sixth groove 2.6 are -90 to -45°, -60 to -30°, and -30 to -15° respectively. The design of each groove 2 should be based on non-interference; if there is interference between the grooves 2, it will be excluded in the subsequent parameter optimization design process.

[0038] In this embodiment, there are two liquid inlets 6. The starting positions of some grooves (i.e., three grooves) are set with the center of the lower liquid inlet 6, and the remaining grooves (i.e., the other three grooves) are symmetrically arranged with the middle line of the width direction of the stamping plate 1 as the axis. The front section 2.7 of the groove includes an arc section 2.7.1 and a horizontal section 2.7.2. The starting position of the arc section 2.7.1 is also the starting position of the front section 2.7 of the groove; the end of the arc section 2.7.1 is horizontally tangent to the starting point of the horizontal section 2.7.2, and the end of the horizontal section 2.7.2 is horizontally connected to the starting point of the middle section 2.8 of the groove. The incident angle of the first groove 2.1 is 25°, and the angle β1 between the tangent line at the starting point of the corresponding arc section and the X-axis is 90°; the incident angle of the second groove 2.2 is 45°, and the angle β2 between the tangent line at the starting point of the corresponding arc section and the X-axis is 60°; the incident angle of the third groove 2.3 is 65°, and the angle β3 between the tangent line at the starting point of the corresponding arc section and the X-axis is 30°. If N grooves 2 are designed, the difference between the incident angles of two adjacent grooves 2 does not exceed 180° / N; the difference between the angles between the tangent lines at the starting points of the arc sections of two adjacent grooves 2 and the X-axis is 180° / N.

[0039] Preferably, the distance between two adjacent grooves 2 is 35 - 60 mm. In the present invention, the specific distance between two adjacent grooves 2 can be adjusted according to the actual situation.

[0040] Preferably, the width of the groove 2 is 6 - 10 mm. In the present invention, the width of the groove 2 is set to ensure the connection strength after brazing the stamping plate 1 and the bottom plate 3.

[0041] In the present invention, the corrugated power battery liquid cooling plate member is connected to the battery module 5 through a heat conducting pad 4 to export the heat of the battery module 5.

[0042] As Figure 6 and Figure 7 shown in a power assembly, which includes the battery liquid cooling plate member as described above, as well as a heat conducting pad 4 and a battery module 5. The bottom plate 3 of the battery liquid cooling plate member is connected to the battery module 5 through the heat conducting pad 4.

[0043] Embodiment 1 As Figures 1-3 shown in the corrugated power battery liquid cooling plate member, which includes a stamping plate 1 and a bottom plate 3; the bottom plate 3 of the battery liquid cooling plate member is connected to the battery module 5 through a heat conducting pad 4.

[0044] Embodiment 2 In this embodiment, an optimization design is carried out on the structural parameters of Embodiment 1. A method for optimizing the design of the structure of a corrugated power battery liquid cooling plate member is as follows: Step 1: Construct a three-dimensional model in which the battery liquid cooling plate member is connected to the battery module 5 through a heat conducting pad 4, obtain relevant model parameters, and determine the variable parameters to be optimized.

[0045] In this embodiment, the relevant model parameters are shown in Table 1; the structural parameters of the battery liquid cooling plate member include the starting position of the groove 2, the distance between the grooves 2, the corrugation amplitude of the groove 2, etc.; the variable parameters to be optimized are shown in Table 2. By optimizing the relevant parameters of the battery liquid cooling plate member, the flow of the coolant can be changed, thereby changing the performance parameters of the liquid cooling plate and optimizing the performance of the battery liquid cooling plate member.

[0046] Table 1 Relevant model parameters

[0047] Table 2 Variable parameters to be optimized and their value ranges

[0048] The conversion relationship of the relevant parameters is: (2).

[0049] In Table 1 and formula (2), as Figure 5As shown in the figure, Angle1 is the incident angle α1 of the first groove 2.1; Angle2 represents the incident angle α2 of the second groove 2.2; Angle3 represents the incident angle α3 of the third groove 2.3; AngleIncrument1 represents the increment of Angle2 relative to Angle1, and AngleIncrument2 represents the increment of Angle3 relative to Angle2. Width1 represents the spacing A1 between the third groove 2.3 and the fourth groove 2.4, Width2 represents the spacing A2 between the second groove 2.2 and the third groove 2.3, in mm; Width3 represents the spacing A3 between the first groove 2.1 and the second groove 2.2, in mm; WidthIncrument1 represents the increment of Width2 relative to Width1, and WidthIncrument2 represents the increment of Width3 relative to Width2, in mm. High is the peak height h1, in mm; Low is the trough height h2, in mm; the initial values and value ranges of the relevant parameters are shown in Table 2. Step 2: Taking the maximization of the heat transfer coefficient HTC of the cold plate and the minimization of the pressure drop DP at the inlet and outlet of the cold plate as the optimization objectives, and taking the temperature difference of the heat transfer surface as the constraint condition, a multi-objective optimization calculation model is established.

[0050] In the present invention, the multi-objective optimization calculation model is: (3); In the formula, represents the variable parameters to be optimized, where x 1 represents the incident angle of the first groove 2.1; x 2 is the incident angle of the second groove 2.2; x 3 is the incident angle of the third groove 2.3; x 4 is the spacing between the third groove 2.3 and the fourth groove 2.4, in mm; x 5 is the spacing between the second groove 2.2 and the third groove 2.3, in mm; x 6 is the spacing between the first groove 2.1 and the second groove 2.2, in mm; x 7 is the peak height, in mm; x 8 is the trough height; the unit is mm; DP represents the pressure drop at the inlet and outlet, the unit is mbar; HTC represents the heat transfer coefficient, the unit ; represents the temperature difference of the heat transfer surface, the unit is °C; Restrict the maximum temperature difference of the heat transfer surface, and take 5 °C in this embodiment.

[0051] In the present invention, the heat transfer coefficient HTC is calculated by the following formula: (4); In the formula refers to the heat source power, in W; Refers to the heat transfer surface area, m 2 ; and represent the average temperature of the heat transfer surface and the average temperature of the fluid under the heat transfer surface, °C, respectively.

[0052] In the present invention, the pressure drop DP at the inlet and outlet of the battery liquid cooling plate is calculated by the following formula: (5); In the formula, and represent the pressures at the inlet and outlet of the battery liquid cooling plate, mbar, respectively.

[0053] In the present invention, the calculation methods of the heat transfer coefficient HTC and the pressure drop DP at the inlet and outlet of the battery liquid cooling plate are both existing mature technologies and will not be elaborated here.

[0054] Step 3: Import the 3D model into Star-CCM+ and then mesh it, set the boundary conditions, and combine the multi-objective optimization calculation model and the SHERPA hybrid adaptive algorithm (Simultaneous Hybrid Exploration that is Robust, Progressive, and Adaptive) to perform a simulation analysis on the 3D model under different variable parameter values, and calculate the corresponding battery liquid cooling plate performance data, including the heat transfer coefficient HTC and the pressure drop DP.

[0055] In the present invention, the model is imported into STAR-CCM+ and the grid is obtained using its built-in automatic mesh generator. When performing relevant settings, the boundary conditions need to be defined. The mass flow rate and the inlet temperature of the coolant at the inlet 6 of the battery liquid cooling plate are 0.4 kg / s and 30 °C respectively, and the ambient temperature is set to 30 °C. The outlet type is a pressure outlet and is set to 0 Pa, ignoring the heat exchange between the liquid cooling plate and the air; by applying a constant uniform heat source of 1000 W to the bottom of the thermal pad 4 to replace the heat generation of the battery constant heat source, and using the temperature change of the heating surface of the thermal pad 4 to replace its influence on the cooling performance of the battery; the flow model selects the Realizable k-ε turbulence model. A steady-state calculation is adopted with 2000 iteration steps. To ensure the cooling effect and considering the actual situation, the material of the battery liquid cooling plate is aluminum, and the coolant is a 50% ethylene glycol solution. The relevant parameters are shown in Table 3 below. To simplify the analysis, the following assumptions are made during the simulation process: 1) The flow rate and heat of the coolant are always in a stable state during the transfer process; 2) The fluid is incompressible, and the thermophysical properties of the coolant and the liquid cooling plate material are independent of temperature; 3) The no-slip boundary condition is applied at the solid-liquid interface; 4) The influence of gravity is ignored.

[0056] Table 3 Relevant parameters of the coolant and materials

[0057] In this embodiment, some of the performance data of the battery liquid cooling plate obtained are shown in Table 4.

[0058] Table 4 Performance data of the battery liquid cooling plate under partial value conditions of the variable parameters

[0059] In the present invention, the evaluation quantity of the SHERPA algorithm is usually 50 × the number of objective functions × the number of design variables; in this embodiment, 800 groups of data are taken.

[0060] Step Four: Analyze the performance data of the battery liquid cooling plate to obtain the Pareto solution set of multi-objective optimization, and select the Pareto front solution set.

[0061] In this embodiment, as Figure 8 shown is the obtained Pareto solution set, where the red dots are the Pareto front solution set. The Pareto front solution set is a subset of the Pareto solution set and is the boundary or front part formed by the objective function values corresponding to all Pareto optimal solutions in the objective function space, representing all optimal trade-off solutions in the multi-objective optimization problem. In the present invention, the obtaining of the Pareto solution set and the Pareto front solution set are both prior arts and will not be elaborated here.

[0062] Step Five: Introduce the comprehensive evaluation score , and find the optimal solution in the Pareto front solution set to obtain the best values of each variable parameter.

[0063] In the present invention, the comprehensive evaluation score is introduced, calculate the comprehensive evaluation scores introduced for each group of data in the Pareto front solution set and compare them. The values of each variable parameter in the group of data with the highest comprehensive evaluation score R are the best values.

[0064] The comprehensive evaluation score R is obtained from the following equation: (6); In the formula: is the comprehensive evaluation score, without unit; is the weight matrix, L 1 、L 2 、L 3 are the weight coefficients of the pressure drop, heat transfer coefficient, and heat transfer surface temperature difference in sequence, without unit. In the present invention, a design scheme in which the pressure drop and the heat transfer coefficient each account for half of the weight is selected; at the same time, the smaller the pressure drop, the better, so its weight coefficient needs to be negative; then the weight matrix takes =[-0.5, 0.5, 0], that isL 1 、L 2 、L 3 takes values of 0.5, 0.5, and 0 in sequence; at the same time, due to the difference in the order of magnitude between different objective functions, normalization processing of the evaluation index is required. is the normalized evaluation index matrix; are the corresponding indicators of pressure drop, heat transfer coefficient, and temperature difference of the heat transfer surface respectively, and the calculation formula is: (7); In formula (4), i = 1, 2, 3, which respectively represent the three corresponding indicators of pressure drop, heat transfer coefficient, and temperature difference of the heat transfer surface in sequence; is the value corresponding to the index; is the minimum value corresponding to the index; is the maximum value corresponding to the index. The maximum value and the minimum value are respectively the maximum value and the minimum value in all the data obtained for the corresponding index.

[0065] In the present invention, in the Pareto front solution set, the fifth group of data and the sixth group of data in Table 4 are selected, and the calculated performance indicators are respectively: pressure drop 463.08 mbar, 480.52 mbar, heat transfer coefficient 2405.48 , 2422.03 ; the maximum value and the minimum value of the pressure drop are 583.25 mbar and 360.89 mbar respectively, and the maximum value and the minimum value of the heat transfer coefficient are 2581.98 and 1664.46 . Then the comprehensive evaluation scores and are respectively: =-0.5×(463.08 - 360.89) / (583.25 - 360.89)+0.5×(2405.48 - 1664.46) / (2581.98 - 1664.46)=0.174; =-0.5×(480.52 - 360.89) / (583.25 - 360.89)+0.5×(2422.03 - 1664.46) / (2581.98 - 1664.46)=0.144.

[0066] Therefore, select =0.174 corresponding parameters, that is, Angle1 = 28°, Angle2 = 44°, Angle3 = 62°, Width1 = 40 mm, Width2 = 40 mm, Width3 = 40 mm, High = 22 mm, Low = 24 mm, as the relative optimization scheme.

[0067] Table 5 Structural parameters and performance indicators before and after optimization

[0068] In this embodiment, by comparing the comprehensive evaluation scores of each group of data in the Pareto front solution set R , the optimal values of each optimization parameter in this embodiment are obtained. The values of relevant structural parameters before and after optimization and the corresponding performance indicators are shown in Table 5. The temperature nephograms of the heat transfer surface before and after optimization are as Figure 9 shown, and the pressure drop and heat transfer coefficient before and after optimization are as Figure 10 shown. According to Table 5 Figure 9 and Figure 10 , it can be seen that the optimized scheme finally obtained has a relatively small change in the pressure drop of the original cold plate, the heat transfer coefficient increases by 10.66%, and the thermal uniformity of the heat transfer surface is still within the range of the uniformity requirement. The heat transfer effect is greatly improved while the pressure drop only increases by 2.4%, meeting the design requirements; at the same time, the energy consumption ratio of the optimized scheme is greatly improved compared with the original scheme, and it is relatively more economical and more efficient.

[0069] The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

[0070] Although the present invention has been described here with reference to the illustrative embodiments of the present invention, the above embodiments are only the preferred embodiments of the present invention, and the embodiments of the present invention are not limited by the above embodiments. It should be understood that those skilled in the art can design many other modifications and embodiments, and these modifications and embodiments will fall within the scope and spirit of the principles disclosed in this application.

Claims

1. An optimized design method for the structure of a corrugated power battery liquid cooling plate, characterized in that, The method includes the following steps: constructing a three-dimensional model in which a battery liquid cooling plate is connected to a battery module through a heat conduction pad, obtaining relevant structural parameters of the model, and determining variable parameters to be optimized; taking maximizing the heat transfer coefficient of the cold plate and minimizing the pressure drop at the inlet and outlet of the cold plate as optimization objectives, and taking the temperature difference of the heat transfer surface as a constraint condition to establish a multi-objective optimization calculation model; performing a simulation analysis on the three-dimensional model under different values of the variable parameters, and combining with the multi-objective optimization calculation model to calculate and obtain the performance data of the battery liquid cooling plate under the corresponding values, including the heat transfer coefficient and the pressure drop; analyzing the performance data of the liquid cooling plate to obtain a Pareto solution set for multi-objective optimization, and selecting a Pareto front solution set; introducing a comprehensive evaluation score to find the optimal solution in the Pareto front solution set and obtain the best values of the variable parameters.

2. The optimized design method for the corrugated power battery liquid cooling plate structure according to claim 1, characterized in that, The battery liquid cooling plate includes a stamping plate and a bottom plate. Liquid inlets and outlets are respectively arranged at both ends of the stamping plate, and a plurality of downward grooves are arranged on the stamping plate between the liquid inlets and outlets; the stamping plate is stacked on the bottom plate, and the bottom of the groove of the stamping plate is fixedly connected to the upper surface of the bottom plate, and a coolant flow area is formed between the stamping plate and the bottom plate. One end of the coolant flow area is an inlet area communicated with the liquid inlet on the stamping plate, and the other end of the coolant flow area is an outlet area communicated with the liquid outlet on the stamping plate; the grooves divide the coolant flow area into a plurality of flow channels, and both ends of each flow channel are communicated with the inlet area and the outlet area respectively; Along the direction from the inlet area to the outlet area, the grooves are divided into a groove front section, a groove middle section and a groove rear section that are sequentially connected end to end; the groove middle section is in a corrugated shape; the groove rear section is symmetrically arranged with the groove front section at both ends of the groove middle section; each groove front section is symmetrically arranged with the inlet area as the center, and each groove middle section is arranged in parallel with each other.

3. The optimized design method for the corrugated power battery liquid cooling plate structure according to claim 2, characterized in that, The corrugated shape of each groove middle section is consistent with the image of a trigonometric function; taking the center of the stamping plate as the origin, taking the width direction of the stamping plate as the Y direction, and taking the length direction of the stamping plate as the X direction to establish a coordinate system, then the corrugated shape of the groove middle section satisfies the following trigonometric function relation: （1）； Among them, y is the Y - coordinate of the groove, with the unit of mm; x is the X - coordinate of the groove, with the unit of mm; A is the amplitude, with the unit of mm; λ is the wavelength, with the unit of mm; h i is the Y - direction distance from the i - th groove to the center of the stamping plate, with the unit of mm.

4. The optimized design method of the corrugated power battery liquid cooling plate structure according to claim 3, characterized in that, The starting positions of each groove are all located on a circle with a radius of 80-90 mm centered on the foot of the perpendicular of the center of the liquid inlet on the edge of the stamping plate.

5. The optimized design method for the corrugated power battery liquid cooling plate structure according to claim 4, characterized in that There are two liquid inlets. The starting positions of some grooves are set at the center of the lower liquid inlet, and the rest are symmetrically arranged with the midline in the width direction of the stamping plate as the axis of symmetry; the groove front section includes an arc section and a horizontal section, and the starting position of the arc section is also the starting position of the groove front section; the end of the arc section is horizontally tangent to the starting point of the horizontal section, and the end of the horizontal section is horizontally connected to the starting point of the groove middle section.

6. The optimized design method for the corrugated power battery liquid cooling plate structure according to claim 5, characterized in that, The first groove to the sixth groove are sequentially arranged on the stamping plate in the width direction; the multi-objective optimization calculation model is: （3）； In the formula, represents the variable parameters to be optimized, where x 1 represents the incident angle of the first groove; x 2 is the incident angle of the second groove; x 3 is the incident angle of the third groove; x 4 is the distance between the third groove and the fourth groove, in mm; x 5 is the distance between the second groove and the third groove, in mm; x 6 is the distance between the first groove and the second groove, in mm; x 7 is the wave crest height, in mm; x 8 is the wave trough height; the unit is mm; DP represents the pressure drop between the inlet and outlet, the unit is mbar; HTC represents the heat transfer coefficient, the unit ; represents the temperature difference of the heat transfer surface, the unit is °C; limits the maximum temperature difference of the heat transfer surface.

7. The optimized design method for the corrugated power battery liquid cooling plate structure according to claim 6, characterized in that, The method for performing a simulation analysis on the three-dimensional model under different values of the variable parameters is: importing the three-dimensional model into Star -CCM + for meshing, setting boundary conditions, and combining with the multi-objective optimization calculation model and the SHERPA hybrid adaptive algorithm to perform a simulation analysis on the three-dimensional model under different values of the variable parameters and calculate and obtain the corresponding data.

8. The optimized design method for the corrugated power battery liquid cooling plate structure according to claim 6, characterized in that, Comprehensive evaluation score R Obtained from the following equation: （6）； where: is the comprehensive evaluation score, without unit; is the weight matrix, L 1 、L 2 、L 3 are the weight coefficients of pressure drop, heat transfer coefficient and temperature difference of heat transfer surface in sequence, without unit, L 1 、L 2 、L 3 take values of 0.5, 0.5, 0 in sequence; is the normalized evaluation index matrix; are the corresponding indexes of pressure drop, heat transfer coefficient and temperature difference of heat transfer surface in sequence, and the calculation formula is: （7）； In formula (4), i = 1, 2, 3, respectively represent the three corresponding indicators of pressure drop, heat transfer coefficient, and temperature difference of the heat transfer surface in sequence; is the value corresponding to the indicator; is the minimum value corresponding to the indicator; is the maximum value corresponding to the indicator.

9. The optimized design method for the corrugated power battery liquid cooling plate structure according to claim 6, characterized in that, The heat transfer coefficient HTC is calculated using the following formula: （4）； where denotes the heat source power, W; denotes the heat transfer surface area, m 2 ; , respectively represent the average temperature of the heat transfer surface and the average temperature of the fluid below the heat transfer surface, °C.

10. The optimized design method for the corrugated power battery liquid cooling plate structure according to claim 6, characterized in that, The pressure drop DP at the inlet and outlet of the battery liquid cooling plate is calculated using the following formula: （5）； Wherein, and represent the pressures at the inlet and outlet of the battery liquid cooling plate member, respectively, in mbar.

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