Optimization method for cooling performance of liquid cooling plate of power battery

Abstract

The invention relates to the field of thermal management of power batteries, in particular to a method for optimizing the cooling performance of a liquid cooling plate of a power battery. The optimization method comprises the following steps: firstly, calculating an estimated value of a heat dissipation demand of the power battery pack, and determining a size range of a liquid cooling pipeline in a liquid cooling plate and a peripheral size of the liquid cooling plate; determining the topological form of the liquid cooling loop, and constructing an optimization model by taking the size parameters and topological position parameters of each section of the liquid cooling plate pipeline as variables; turbulence enhancement and heat transfer enhancement are realized by utilizing the enhanced heat transfer unit, the heat transfer efficiency of the liquid cooling pipeline is improved, and then step-by-step optimization is carried out on the liquid cooling pipeline, the arrangement mode of the enhanced heat transfer unit and the size of the enhanced heat transfer unit by adopting a multi-layer optimization method, so that the NP problem is prevented from being solved, and the solution efficiency is relatively high; and an optimization scheme meeting engineering requirements can be obtained. According to the invention, multi-objective optimization can be carried out for different performance indexes of the liquid cooling pipeline, so that the method has wide applicability.

Description

Technical Field

[0001] The present invention relates to the field of thermal management of power batteries, and in particular to a method for optimizing the cooling performance of a liquid cooling plate of a power battery. Background Art

[0002] With the rapid development of electric vehicles and energy storage systems, the energy density of power batteries has increased year by year, and the rapid development of fast charging technology has led to an increasing demand for heat dissipation in power batteries. The performance of its thermal management system has increasingly become a bottleneck technology that restricts the development of the new energy vehicle industry. An efficient heat dissipation system is not only conducive to improving the performance of power batteries, but also extends the service life of power batteries and ensures safety.

[0003] Automotive power batteries usually use a liquid cooling system for thermal management. Liquid cooling pipes are arranged inside the liquid cooling plate, and most liquid cooling pipes adopt an S-shaped topology. On the one hand, it has the characteristics of a simple structure and can be stamped and formed in one step. On the other hand, it can basically guarantee the heat dissipation requirements of the entire battery pack. It is also possible to arrange multiple parallel liquid cooling pipes or optimize the pipe topology to avoid excessive temperature differences between the pipe inlet and outlet, thereby improving the temperature consistency of the battery pack.

[0004] Most of the current liquid cooling plates used in electric vehicles use smooth cooling pipes. Arranging heat transfer enhancement units such as pits, convex humps, and fins in the liquid cooling pipes can significantly improve the heat transfer efficiency and meet the heat dissipation requirements of the new generation of power batteries with large capacity and high energy density. However, due to the introduction of enhanced heat transfer units, the design variables have increased significantly. In fact, the optimization problem of this type of liquid cooling plate belongs to the NP problem, which has problems such as high solution complexity and low efficiency. Summary of the invention

[0005] The purpose of the present invention is to address the deficiencies in the prior art and provide a method for optimizing the cooling performance of a liquid cooling plate with an enhanced heat transfer unit for automotive power batteries. The enhanced heat transfer unit is used to achieve turbulence enhancement and heat transfer enhancement, thereby improving the heat transfer efficiency of the liquid cooling pipeline. A multi-layer optimization method is then used to optimize the liquid cooling pipeline, the arrangement of the enhanced heat transfer unit, and the size of the enhanced heat transfer unit in steps, which not only avoids solving the NP problem but also meets the actual needs of the project.

[0006] The technical solution provided by the present invention is:

[0007] A method for optimizing the cooling performance of a power battery liquid cooling plate comprises the following steps:

[0008] Step 1: Calculate the estimated heat dissipation requirements of the power battery pack and determine the size range of the liquid cooling pipe inside the liquid cooling plate and the outer size of the liquid cooling plate;

[0009] Step 2: Determine the topology of the liquid cooling circuit, use the size parameters and topological position parameters of each section of the liquid cooling plate pipeline as variables, build a first optimization model, and use the first optimization model to obtain the smooth pipeline solution with the best performance;

[0010] Step 3: Using the optimal smooth pipeline solution obtained in step 2 as the initial solution, a combination of enhanced heat transfer units is arranged on the pipeline wall, and the type of enhanced heat transfer units and the combination of units are used as variables to construct a second optimization model. The second optimization model is used to obtain the enhanced heat transfer unit combination solution with the best performance;

[0011] Step 4: Take the optimal smooth pipeline solution obtained in step 2 as the initial solution, adopt the optimal enhanced heat transfer unit combination solution obtained in step 3, and use the geometric dimensions of the enhanced heat transfer unit monomer and the arrangement dimensions of the unit combination as variables to construct a third optimization model. Use the third optimization model to obtain the pipeline solution with the optimal cooling performance of the power battery liquid cooling plate.

[0012] The above method further comprises: calculating the estimated heat dissipation demand of the power battery pack in step 1, selecting an RC equivalent circuit model to construct a power battery model, then obtaining battery data using an HPPC experiment, and then obtaining model parameters of the RC equivalent circuit model using parameter identification.

[0013] The term "heat transfer enhancement unit" in the optimization method is used to represent functional elements such as pits, convex humps, fins, vortex generators, etc. with various shapes that can achieve turbulence enhancement. "Heat transfer enhancement unit combination" and "arrangement of unit combination" are used to represent the combination of heat transfer enhancement units that can achieve turbulence enhancement, and have the same meaning, including the combination and arrangement of the same type of heat transfer enhancement units with the same shape and size, the combination of the same type of heat transfer enhancement units with different shapes and sizes, and the combination of different types of heat transfer enhancement units.

[0014] In the above method, further, the calculation method of the power battery pack heat dissipation demand estimation in step 1 is:

[0015]

[0016] Where n is the order of the RC equivalent circuit model, R i (i=0,1,2…,n) is the resistance of each level of the RC equivalent circuit model, I is the maximum operating current of the RC equivalent circuit model, and S is the safety factor.

[0017] In the above method, further, in steps 2 to 4, maximizing the average Nusselt number of the wall of the liquid cooling pipe is used as the objective function, and the cooling performance of the liquid cooling plate is maximized by using an orthogonal test.

[0018] In the above method, further, in steps 2 to 4, the cooling performance of each scheme and the optimized scheme is analyzed by fluid-heat coupling simulation.

[0019] In the above method, further, in step three, the optimization design is no longer performed, but a combination scheme of enhanced heat transfer units with alternating straight line arrangements of concave pits and convex hulls is directly adopted.

[0020] The above method, further, in step 4, when the heat transfer enhancement unit is a pit, the pit width and the ratio of depth to width are selected as optimization variables; the pit width W d The value range is: 0.5W≤W d ≤0.83W, where W is the channel width, the ratio of the depth and width of the pit δ d The value range is: 0.1≤δ d ≤0.3.

[0021] In the above method, further, in step 4, when the heat transfer enhancement unit is a convex hull, a fin, and a vortex generator, the incident flow width, i.e., the dimension of the heat transfer enhancement unit in a direction perpendicular to the flow direction, and the ratio of the depth to the width are selected as optimization variables;

[0022] When the enhanced heat transfer unit arranged in the upstream region is a pit, the width of the enhanced heat transfer unit ranges from:

[0023] 1.2W d ≤W p ≤W, where W d is the width of the pit, W is the flow channel width, W p is the width of the convex hull;

[0024] For other working conditions, the width of the enhanced heat transfer unit is in the range of 0.5W≤W p ≤W;

[0025] When the enhanced heat transfer unit is a convex hull, the ratio of its height to width δ p The value range is 0.1 to 0.3.

[0026] Compared with the prior art, the present invention has the following characteristics:

[0027] (1) The present invention utilizes a heat transfer enhancement unit to achieve turbulence enhancement and heat transfer enhancement, greatly improving the heat transfer efficiency of the liquid cooling pipeline, and can better meet the growing energy density and heat dissipation requirements of power batteries.

[0028] (2) The present invention utilizes two-layer to three-layer orthogonal experiments to solve the optimization problem of the enhanced heat transfer pipeline, avoiding the original solution method of combined optimization and nested parameter optimization. Instead, the present invention uses three-layer orthogonal optimization to optimize the liquid cooling pipeline, the arrangement of the enhanced heat transfer unit, and the size of the enhanced heat transfer unit in steps. This not only avoids solving the NP problem, but also has a high solution efficiency and can obtain an optimization solution that meets engineering needs.

[0029] (3) The present invention can perform multi-objective optimization on different performance indicators of liquid cooling pipelines, and therefore has wide applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The figure is a schematic diagram of the process of the optimization method of the present invention.

[0031] Figure 2 A schematic diagram of a power battery liquid cooling system is used when executing the optimization method of the present invention.

[0032] Figure 3 The invention relates to a liquid cooling pipeline inside a liquid cooling plate used when executing the optimization method of the present invention.

[0033] Figure 4 This is a schematic diagram of arranging fins as enhanced heat transfer units inside a liquid cooling pipeline in Example 1.

[0034] Figure 5 This is a schematic diagram of the geometric dimensions and arrangement dimension parameters of the fin monomer in Example 1.

[0035] Figure 6 This is a schematic diagram of the geometric dimensions and arrangement size parameters of the individual pits in Example 2.

[0036] Figure 7 This is a schematic diagram of the geometric dimensions and arrangement dimension parameters of the monomers of the convex hull in Example 3.

[0037] Figure 8 This is a schematic diagram of the arrangement of the fin-dimple alternating linear arrangement as the enhanced heat transfer unit combination solution in the liquid cooling pipeline in Example 4.

[0038] Fig. 9 This is a schematic diagram of the arrangement of the fin-convex hull alternating linear arrangement as the enhanced heat transfer unit combination solution in the liquid cooling pipeline in Example 5.

[0039] Fig.10 This is a schematic diagram of Example 6, in which an alternating straight line arrangement of concave and convex humps is selected as a combination scheme for enhancing the heat transfer unit arrangement inside a liquid cooling pipeline.

[0040] Fig.11This is a schematic diagram of Example 7, in which the alternating straight line arrangement of fins, dimples and convex humps is selected as the enhanced heat transfer unit combination solution for arrangement inside the liquid cooling pipeline.

[0041] Description of the reference numerals in the figures: 1. Power battery pack, 2. Liquid cooling plate, 3. Fin, 4. Pits, 5. Convexities. DETAILED DESCRIPTION

[0042] The following is a further detailed description of the invention in conjunction with the accompanying drawings and embodiments, but it is not intended to be a basis for any limitation of the invention. The advantages of the present invention can be further illustrated by the following simulation examples:

[0043] Example 1

[0044] In the design stage, the heat dissipation requirements of the power battery pack are estimated by the second-order RC model. In the optimization stage, the orthogonal test model is used to optimize the liquid cooling pipeline to obtain the optimal performance solution and arrange fins in the liquid cooling pipeline as an enhanced heat transfer unit to improve the heat dissipation performance of the liquid cooling system. This embodiment has the advantages of simple structure, high efficiency, and good heat dissipation effect.

[0045] Optimization method reference Figure 1 , the specific steps are as follows:

[0046] Step 1: Calculate the estimated heat dissipation demand of the power battery pack and determine the size range of the liquid cooling pipe inside the liquid cooling plate and the outer size of the liquid cooling plate;

[0047] A second-order RC model is constructed, and the model parameters are obtained using HPPC experimental data and parameter identification. For the second-order RC equivalent circuit model, the calculation method for estimating the heat dissipation demand of the power battery pack is:

[0048] Q=S(R0+R1+R2)I 2

[0049] Among them, R0 is the ohmic internal resistance of the second-order RC equivalent circuit model, R i is the resistance parameter of the high-order RC equivalent circuit model;

[0050] according to Figure 2 The size of the battery pack is 1.2 times larger, and the outer dimensions of the liquid cooling plate and the size range of the liquid cooling pipes inside the liquid cooling plate are determined;

[0051] Step 2: Determine the topology of the liquid cooling circuit, use the size parameters and topological position parameters of each section of the liquid cooling plate pipeline as variables, build a first optimization model, and use the first optimization model to obtain the smooth pipeline solution with the best performance;

[0052] Liquid cooling plate piping topology Figure 3As shown, the inlet height H, inlet width W of the liquid cooling plate, and the width D of each internal liquid cooling pipeline are selected. i The parameters of are variables, and the objective function is to maximize the average Nusselt number of the liquid cooling pipe wall. The orthogonal test table of the liquid cooling plate pipe is constructed, as shown in Table 1. After solving, the optimal smooth pipe optimization scheme is obtained;

[0053] Table 1 Orthogonal test table of liquid cooling plate pipeline

[0054]

[0055]

[0056] Step 3: Using the optimal smooth pipe optimization solution obtained in step 2 as the initial solution, fins are arranged inside the pipe as an enhanced heat transfer unit, such as Figure 4 As shown;

[0057] Step 4: If Figure 5 As shown, the fin length L, height ratio λ, layout angle α and other size parameters and layout spacing D and other topological parameters are selected as optimization variables. The average Nusselt number of the liquid cooling pipeline wall is maximized as the objective function to build an orthogonal test model. The orthogonal test table is shown in Table 2. After solving, the pipeline solution with the best performance is obtained.

[0058] Table 2 Orthogonal test table of fins as enhanced heat transfer units

[0059]

[0060]

[0061] Example 2

[0062] In the design stage, the heat flux is used to estimate the heat dissipation requirements of the power battery pack. In the optimization stage, the liquid cooling pipeline is optimized to obtain the optimal performance solution and pits are arranged in the liquid cooling pipeline as enhanced heat transfer units, thereby improving the heat dissipation performance of the liquid cooling system. This embodiment has the advantages of simplicity and high efficiency.

[0063] Optimization method reference Figure 1 , the specific steps are as follows:

[0064] Step 1: The heat flux applied on the surface of the liquid cooling plate is used as an estimate of the heat dissipation demand of the power battery pack. The calculation method is:

[0065] Q=qAΔt

[0066] Where Q is the estimated heat dissipation demand of the power battery pack, q is the heat flux per unit area, A is the surface area of ​​the liquid cooling plate, and Δt is the time interval for heat transfer;

[0067] Step 2 is the same as in Example 1;

[0068] Step 3: Take the optimal smooth pipe optimization solution obtained in step 2 as the initial solution and select the pit as the enhanced heat transfer unit, such as Figure 6 As shown;

[0069] Step 4: If Figure 6 As shown, the width W of the pit is selected d , the depth of the pit H d and width W d The ratio δ d As the size parameter, the layout spacing D is selected as the topological parameter as the variable, and the average Nusselt number of the liquid cooling pipeline wall is maximized as the objective function to build an orthogonal test model. The orthogonal test table is shown in Table 3. After solving, the pipeline solution with the best performance is obtained;

[0070] Table 3 Orthogonal test table of pits as enhanced heat transfer units

[0071]

[0072] In step five, the HPPC experimental data is imported into the second-order RC equivalent circuit model to estimate the heat dissipation demand of the power battery pack, which is applied to the initial liquid cooling plate solution, the optimal smooth pipeline optimization solution in step two, the optimal enhanced heat transfer combination solution in step three, and the pipeline solution with the best performance in step four, and the average Nusselt number of the liquid cooling pipeline wall is maximized to verify the effectiveness of the optimization method.

[0073] Example 3

[0074] In the design stage, the heat source is used as an estimate of the heat dissipation demand of the power battery pack. In the optimization stage, the liquid cooling pipeline is optimized to obtain the optimal performance solution and fins are arranged in the liquid cooling pipeline as an enhanced heat transfer unit to improve the heat dissipation performance of the liquid cooling system. This embodiment has the advantages of simple structure, high efficiency, and good heat dissipation effect.

[0075] Optimization method reference Figure 1 , the specific steps are as follows:

[0076] Step 1: The heat flux applied on the surface of the liquid cooling plate is used as an estimate of the heat dissipation demand of the power battery pack. The calculation method is:

[0077]

[0078] Among them, I is the current intensity of the battery during charging and discharging, R is the internal resistance of the battery, T is the battery temperature, Temperature influence coefficient;

[0079] Step 2 is the same as in Example 1;

[0080] Step 3: Using the optimal smooth pipeline optimization solution obtained in step 2 as the initial solution, a convex hull is arranged inside the pipeline as an enhanced heat transfer unit, such as Figure 7 As shown;

[0081] Step 4: If Figure 7 As shown, select the width W of the convex hull p , the height of the convex hull H P and width W p The ratio δ p As the size parameter, the layout spacing D is selected as the topological parameter as the variable, and the average Nusselt number of the liquid cooling pipeline wall is maximized as the objective function to build an orthogonal test model. The orthogonal test table is shown in Table 4 below. After solving, the pipeline solution with the best performance is obtained;

[0082] Table 4 Orthogonal test table of convex hull as enhanced heat transfer unit

[0083]

[0084] The verification part is the same as Example 2.

[0085] Example 4

[0086] In the optimization stage, the liquid cooling pipeline is optimized to obtain the optimal performance solution and a combination solution of enhanced heat transfer units with alternating straight line arrangement of fins and pits is adopted in the liquid cooling pipeline, thereby improving the heat dissipation performance of the liquid cooling system. This embodiment has the advantages of simple structure, high efficiency, good heat dissipation effect, etc.

[0087] Optimization method reference Figure 1 Steps 3 and 4 are implemented according to the following process, and the other steps are the same as those in Example 1:

[0088] Step 3: Using the optimal smooth pipeline optimization solution obtained in step 2 as the initial solution, a heat transfer enhancement unit combination solution with alternating straight lines of fins and dimples is arranged inside the pipeline, such as Figure 8 As shown;

[0089] Step 4: Select the fin length L, fin height ratio λ, fin layout angle α, and pit width W d , the ratio of the depth and width of the pit δ d As the size parameter, the layout spacing D is selected as the topological parameter as the variable, and the average Nusselt number of the liquid cooling pipeline wall is maximized as the objective function to build an orthogonal test model. The orthogonal test table is shown in Table 5. After solving, the pipeline scheme with the best performance is obtained;

[0090] Table 5 Orthogonal test table of fin-pit alternating linear arrangement

[0091]

[0092]

[0093] The verification part is the same as Example 2.

[0094] Example 5

[0095] In the optimization stage, the liquid cooling pipeline is optimized to obtain the optimal performance solution and a combination solution of enhanced heat transfer units with alternating straight line arrangement of fins and convex hulls is adopted in the liquid cooling pipeline, thereby improving the heat dissipation performance of the liquid cooling system. This embodiment has the advantages of simple structure, high efficiency, good heat dissipation effect, etc.

[0096] Optimization method reference Figure 1 Steps 3 and 4 are implemented according to the following process, and the other steps are the same as those in Example 1:

[0097] Step 3: Using the optimal smooth pipeline optimization solution obtained in step 2 as the initial solution, a heat transfer enhancement unit combination solution with alternating straight line arrangements of fins and convex hulls is arranged inside the pipeline, such as Fig. 9 As shown;

[0098] Step 4: Select the length L of the fin, the height ratio λ of the fin, the arrangement angle α of the fin, and the width W of the convex hull p , the ratio of the height and width of the convex hull δ p As the size parameter, the layout spacing D is selected as the topological parameter as the variable, and the average Nusselt number of the liquid cooling pipeline wall is maximized as the objective function to build an orthogonal test model. The orthogonal test table is shown in Table 6. After solving, the pipeline scheme with the best performance is obtained;

[0099] Table 6 Orthogonal test table of fin-convex hull alternating linear arrangement

[0100]

[0101]

[0102] The verification part is the same as Example 2.

[0103] Example 6

[0104] In the optimization stage, the liquid cooling pipeline is optimized to obtain the optimal performance solution and a combination solution of enhanced heat transfer units with alternating straight line arrangement of pits and convex hulls is adopted in the liquid cooling pipeline, thereby improving the heat dissipation performance of the liquid cooling system. This embodiment has the advantages of simple structure, high efficiency, good heat dissipation effect, etc.

[0105] Optimization method reference Figure 1 Steps 3 and 4 are implemented according to the following process, and the other steps are the same as those in method embodiment 1:

[0106] Step 3: Using the optimal smooth pipeline optimization solution obtained in step 2 as the initial solution, a combination solution of heat transfer enhancement units with alternating straight lines of concave and convex hulls is arranged inside the pipeline, such as Fig.10 As shown;

[0107] Step 4: Select the width W of the pit d , the ratio of the depth and width of the pit δ d , the width of the convex hull W p , the ratio of the height and width of the convex hull δ p As the size parameter, the layout spacing D is selected as the topological parameter as the variable, and the average Nusselt number of the liquid cooling pipeline wall is maximized as the objective function to build an orthogonal test model. The orthogonal test table is shown in Table 7. After solving, the pipeline scheme with the best performance is obtained;

[0108] Table 7 Orthogonal test table of alternating straight line arrangement of pits and convex hulls

[0109]

[0110] The verification part is the same as Example 2.

[0111] Example 7

[0112] In the optimization stage, the liquid cooling pipeline is optimized to obtain the optimal performance solution and a combination solution of enhanced heat transfer units with alternating straight line arrangement of fins, pits and convex hulls is adopted in the liquid cooling pipeline, thereby improving the heat dissipation performance of the liquid cooling system. This embodiment has the advantages of simple structure, high efficiency, good heat dissipation effect, etc.

[0113] Optimization method reference Figure 1 , the other steps are the same as those in method embodiment 1, and step 3 is implemented according to the following process:

[0114] Step 3: Using the optimal smooth pipeline optimization solution obtained in step 2 as the initial solution, a heat transfer enhancement unit combination solution of alternating straight lines of fins, dimples, and convex hulls is arranged inside the pipeline, such as Fig.11 As shown;

[0115] Step 4: Select the length L of the fin, the height ratio λ of the fin, the arrangement angle α of the fin, and the width W of the pit. d , the ratio of the depth and width of the pit δ d , the width of the convex hull W p , the ratio of the height and width of the convex hull δ p As the size parameter, the layout spacing D is selected as the topological parameter as the variable, and the average Nusselt number of the liquid cooling pipeline wall is maximized as the objective function to build an orthogonal test model. The orthogonal test table is shown in Table 8. After solving, the pipeline solution with the best performance is obtained;

[0116] Table 8 Orthogonal test table of fin-dimple-convex hull alternating linear arrangement

[0117]

[0118]

[0119] The verification part is the same as Example 2.

[0120] The present invention is not limited to the above-mentioned embodiments. On the basis of the technical solution disclosed in the present invention, technicians in this field can make some substitutions and deformations to some technical features therein according to the disclosed technical content without creative labor, and these substitutions and deformations are all within the protection scope of the present invention.

Claims

1. A method for optimizing the cooling performance of a power battery liquid cooling plate, characterized in that: The following steps are involved: Step 1: Calculate the estimated heat dissipation requirements of the power battery pack and determine the size range of the liquid cooling pipe inside the liquid cooling plate and the outer size of the liquid cooling plate; Step 2: Determine the topology of the liquid cooling circuit, use the size parameters and topological position parameters of each section of the liquid cooling plate pipeline as variables, build a first optimization model, and use the first optimization model to obtain the smooth pipeline solution with the best performance; Step 3: Using the optimal smooth pipeline solution obtained in step 2 as the initial solution, a combination of enhanced heat transfer units is arranged on the pipeline wall, and the type of enhanced heat transfer units and the combination of units are used as variables to construct a second optimization model. The second optimization model is used to obtain the enhanced heat transfer unit combination solution with the best performance; The heat transfer enhancement unit is used to represent pits, convex humps, fins and vortex generators with various shapes that can achieve turbulence enhancement; Step 4: Take the optimal smooth pipeline solution obtained in step 2 as the initial solution, adopt the optimal enhanced heat transfer unit combination solution obtained in step 3, and use the geometric dimensions of the enhanced heat transfer unit monomer and the arrangement dimensions of the unit combination as variables to construct a third optimization model. Use the third optimization model to obtain the pipeline solution with the optimal cooling performance of the power battery liquid cooling plate.

2. The method for optimizing the cooling performance of a power battery liquid cooling plate according to claim 1, characterized in that: In step 1, the heat dissipation demand of the power battery pack is estimated, an RC equivalent circuit model is selected to construct a power battery model, and then battery data is obtained by HPPC experiment, and model parameters of the RC equivalent circuit model are obtained by parameter identification; The calculation method for estimating the heat dissipation demand of the power battery pack is: Where n is the order of the RC equivalent circuit model, R i is the resistance parameter of the high-order RC equivalent circuit model, i=0,1,2,…n, I is the maximum operating current of the RC equivalent circuit model, and S is the safety factor.

3. The method for optimizing the cooling performance of a power battery liquid cooling plate according to claim 1, characterized in that: In step 3, the enhanced heat transfer unit combination is arranged on the pipe wall surface, and the fin-pit alternating linear arrangement is selected as the enhanced heat transfer unit combination scheme.

4. The method for optimizing the cooling performance of a power battery liquid cooling plate according to claim 1, characterized in that: In step 3, the enhanced heat transfer unit combination is arranged on the pipeline wall surface, and the fin-convex hull alternating linear arrangement is selected as the enhanced heat transfer unit combination scheme.

5. The method for optimizing the cooling performance of a power battery liquid cooling plate according to claim 1, characterized in that: In step 3, the enhanced heat transfer unit combination is arranged on the pipeline wall surface, and a concave-convex hull alternating linear arrangement is selected as the enhanced heat transfer unit combination scheme.

6. The method for optimizing the cooling performance of a power battery liquid cooling plate according to claim 1, characterized in that: In step 3, the enhanced heat transfer unit combination is arranged on the pipeline wall surface, and the fin-pit-convex hull alternating linear arrangement is selected as the enhanced heat transfer unit combination scheme.

7. The method for optimizing cooling performance of a power battery liquid cooling plate according to claim 1, characterized in that: In steps 2 to 4, the objective function is to maximize the average Nusselt number of the wall of the liquid cooling pipe, and the orthogonal test is used to maximize the cooling performance of the liquid cooling plate.

8. The method for optimizing cooling performance of a power battery liquid cooling plate according to claim 1, characterized in that: In steps 2 to 4, the cooling performance of each solution and the optimized solution is analyzed by fluid-heat coupling simulation.

9. The method for optimizing cooling performance of a power battery liquid cooling plate according to claim 1, characterized in that: In step 4, when the heat transfer enhancement unit is a pit, the pit width and the ratio of depth to width are selected as optimization variables; Width of pit W d The value range is: 0.5W≤W d ≤0.83W, where W is the channel width, the ratio of the depth and width of the pit δ d The value range is: 0.1≤δ d ≤0.

3.

10. The method for optimizing cooling performance of a power battery liquid cooling plate according to claim 1, characterized in that: In step 4, when the heat transfer enhancement unit is a convex hull, a fin, and a vortex generator, the incident flow width, i.e., the dimension of the heat transfer enhancement unit in the direction perpendicular to the flow direction, and the ratio of the depth to the width are selected as optimization variables; When the enhanced heat transfer unit arranged in the upstream area is a pit, the width of the enhanced heat transfer unit ranges from: 1.2W d ≤W p ≤W, where W d is the width of the pit, W is the flow channel width, W p is the width of the convex hull; For other working conditions, the width of the enhanced heat transfer unit is in the range of 0.5W≤W p ≤W; When the enhanced heat transfer unit is a convex hull, the ratio of its height to width δ p The value range is 0.1 to 0.3.

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