A thermal simulation meshing method

Abstract

The application discloses a thermal simulation grid division method, which divides a lithium ion battery module simulation model into a battery, a connecting sheet, a flow field and a component; determines the battery grid, the connecting sheet grid, the connecting sheet grid and the component size; and performs grid division on the lithium ion battery module through software according to the determined size, so that the grid quantity can be effectively reduced, the simulation efficiency is improved, and convenience is provided for application of a simulation result in a later period.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of battery thermal management, and particularly relates to a thermal simulation grid division method. BACKGROUND

[0002] In the application process of a lithium ion battery module, battery thermal management is an important guarantee for stable operation of an energy storage system.

[0003] At present, a battery thermal management strategy is mainly formulated through a thermal simulation result, and therefore the accuracy of the simulation result is related to the effectiveness of the thermal management strategy and the safety of the system. In order to obtain an accurate thermal simulation result of the energy storage module, the following conditions are required: 1, an accurate 3D physical model; 2, accurate physical parameters; 3, correct grid division; and 4, suitable equation sets. The grid division is a difficulty, and whether the grid division is appropriate directly affects the simulation result. The grid division is closely related to grid division parameters. Different division methods can obtain different grid numbers, and the grid number directly affects the accuracy of the simulation result. In theory, the greater the grid number, the more accurate the simulation structure, but the greater the grid number, the greater the required computing resources and the longer the calculation time, and therefore how to find a balance point between the grid number and the computing resources has always been a difficulty in simulation work.

[0004] However, in the existing method (such as fluent mesh), the minimum grid size given in the grid division is small, and when the grid is generated, only a set of grid standards is often used. When this set of standards is used for the entire model, the overall grid number of the model is large, the calculation amount is huge, the calculation time is long, and the simulation efficiency is affected.

[0005] Therefore, a suitable grid division method will effectively improve the simulation accuracy, improve the simulation accuracy, and provide convenience for the application of the simulation result in the later stage. SUMMARY

[0006] To overcome the problems in the prior art, the purpose of the present application is to provide a thermal simulation grid division method.

[0007] To achieve the above-mentioned purpose, the technical solution adopted by the present application is as follows:

[0008] A thermal simulation grid division method, comprising the following steps:

[0009] dividing a lithium ion battery module simulation model into a battery, a connecting piece, a flow field and a component;

[0010] determining the battery grid, the connecting piece grid, the connecting piece grid and the component grid size;

[0011] grid dividing the lithium ion battery module according to the battery grid, the connecting piece grid, the connecting piece grid and the component grid size;

[0012] According to the grid division result, the thermal simulation of the lithium ion battery module is realized.

[0013] Further, when the battery thickness is alpha mm, the minimum value of the battery grid size is alpha / N mm, and the maximum value is alpha mm, N is a positive integer.

[0014] Further, when the thickness of the connecting piece is sigma mm, the minimum value of the connecting piece grid size is sigma / M mm, and the maximum value is sigma mm, M is a positive integer.

[0015] Further, when the gap between the batteries is beta mm, the minimum value of the flow field grid size is beta / L mm, and the maximum value is beta mm, L is a positive integer.

[0016] Further, when the minimum size of the component is theta, the minimum value of the component grid size is theta / L mm, and the maximum value is theta mm, L is a positive integer.

[0017] Further, N+M+L=6.

[0018] Further, N=1, M=2, L=3, or N=1, M=3, L=2.

[0019] Further, N=2, M=1, L=3, or N=2, M=3, L=1.

[0020] Further, N=3, M=2, L=1, or N=3, M=1, L=2.

[0021] Further, the grid division of the lithium ion battery module according to the battery grid, the connecting piece grid, the connecting piece grid and the component grid size is realized by the fluent mesh software.

[0022] Compared with the prior art, the present application has the beneficial effects:

[0023] The present application determines the battery grid, the connecting piece grid, the connecting piece grid and the component size by dividing the simulation model of the lithium ion battery module; according to the determined size characteristic parameters, the grid division of the model is realized by software, and the optimization of the grid number of the energy storage module is realized. The grid division method in the present application can reduce the calculation amount in the thermal simulation process and improve the simulation efficiency. The method of the present application can greatly reduce the grid number, and the division method of the present application can shorten the grid division time from 119 min to 18 min, saving time. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The lithium ion battery module is divided into a schematic diagram.

[0025] Figure 2Grid diagram divided by prior art.

[0026] Figure 3 Grid diagram divided by the method of the present application.

[0027] Figure 4 Temperature curves simulated by different grid division methods.

[0028] In the figure, 1 is a battery, 2 is a connecting piece. DETAILED DESCRIPTION

[0029] The present application will be described in detail below with reference to the accompanying drawings.

[0030] The meanings of the terms involved in the present application are explained as follows:

[0031] Fluent mesh: a grid division software.

[0032] Grid division: dividing a physical model into several regions by the finite element method.

[0033] By analyzing the lithium ion battery module simulation model, the characteristic parameters in the model are extracted, the size of the grid is determined by calculation, and the grid division of the model is realized by software.

[0034] Specifically, the lithium ion battery module simulation model is divided into a battery 1, a connecting piece 2, a flow field and other components (i.e. components, the total of components other than the battery, connecting piece and flow field) 4 parts, wherein the spatial grid characteristic value is closely related to the battery gap, and when the thickness of the battery 1 is α mm, the thickness of the connecting piece 2 is σ mm, and the battery gap β mm is a known quantity.

[0035] Therefore, the minimum and maximum values of the grid size of the three parts can be determined:

[0036] The minimum value of the battery grid size is α / N mm, and the maximum value is α mm;

[0037] The minimum value of the connecting piece grid size is σ / M mm, and the maximum value is σ mm;

[0038] The minimum value of the flow field grid size is β / L mm, and the maximum value is β mm;

[0039] Wherein, N, M, L are positive integers.

[0040] In the process of determining the grid size, the present application provides a set of calculation formulas:

[0041] N+M+L=6 (1)

[0042] f(N,M,L)=1 (2)

[0043] g(N,M,L)=0 (3)

[0044] By the above formula, the N, M and L values can be calculated, specifically, N=1, M=2, L=3, or N=1, M=3, L=2, or N=2, M=1, L=3, or N=2, M=3, L=1, or N=3, M=2, L=1, or N=3, M=1, L=2.

[0045] Further, the grid size range of the battery 1, the connecting piece 2 and the flow field is obtained.

[0046] The grid of other components is greatly related to the size of the flow field, so the grid range of other components can use the same setting as the flow field grid. That is, the minimum value of the grid size of other components (i.e. components) is θ / L mm, and the maximum value is θ mm; θ is the minimum size of other components (i.e. components), which can be determined according to the actual situation.

[0047] Thus, the grid size range of the four parts in the lithium ion battery module is determined, and by setting the grid division through the software fluentmesh, the number of grids can be effectively reduced and the simulation efficiency can be improved.

[0048] The present application determines the grid division size of each part of the energy storage module, and since the grid sizes of each part are related to each other, a set of relatively reasonable grid size data can be obtained by calculation. According to the grid division result, the thermal simulation of the lithium ion battery module is realized.

[0049] Referring to Figure 2 , the prior art divides the grid using the default parameters of the software, and the number of grids is about 20 million.

[0050] Referring to Figure 3 , in the following examples, N=4, M=1, L=1, and the specific values of α, σ and β and θ are 25 mm, 3 mm, 4 mm, 3 mm, respectively. The grid is divided by the software Fluent mesh, and the number of grids is about 2 million. By Figure 2 and Figure 3 comparison, it can be seen that the method of the present application can greatly reduce the number of grids, and the division method of the present application shortens the grid generation time from 119 min to 18 min, saving time.

[0051] The present application compares different grid generation methods, and the comparison results are shown in Table 1.

[0052] Table 1: Grid number and grid generation time of different methods

[0053]

[0054] The simulation process is modeling, meshing, boundary condition setting, and finally calculating the results. For the same example, the model, boundary condition, and calculation are the same, only the mesh can be modified, and different meshing will have different simulation results.

[0055] Referring to Figure 4 From the curve data, it can be seen that the simulation result of the meshing method has a maximum error of about 0.6% compared with the simulation result of other meshing methods.

[0056] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application and not to limit them. Although the present application has been described in detail with reference to the above examples, those skilled in the art should understand that the specific embodiments of the present application can still be modified or replaced equivalently without departing from the spirit and scope of the present application, and any modification or equivalent replacement without departing from the spirit and scope of the present application should be covered within the protection scope of the claims of the present application.

Claims

1. A thermal simulation meshing method, characterized in that, The method comprises the following steps: The lithium ion battery module simulation model is divided into a battery, a connecting piece, a flow field and a component; The battery grid, the connecting piece grid, the flow field grid and the component grid size are determined, the minimum value of the battery grid size is α / N mm and the maximum value is α mm when the battery thickness is α mm, N is a positive integer, the minimum value of the connecting piece grid size is σ / M mm and the maximum value is σ mm when the connecting piece thickness is σ mm, M is a positive integer, the minimum value of the flow field grid size is β / L mm and the maximum value is β mm when the gap between the batteries is β mm, L is a positive integer, the minimum value of the component grid size is θ / L mm and the maximum value is θ mm when the minimum size of the component is θ, L is a positive integer, and N+M+L=6; The lithium ion battery module is meshed according to the battery grid, the connecting piece grid, the flow field grid and the component grid size; According to the meshing result, the thermal simulation of the lithium ion battery module is realized.

2. The method of claim 1, wherein, N=1, M=2, L=3, or N=1, M=3, L=2.

3. The method of claim 1, wherein N=2, M=1, L=3, or N=2, M=3, L=1.

4. The method of claim 1, wherein, N=3, M=2, L=1, or N=3, M=1, L=2.

5. The method of claim 1, wherein, The meshing of the lithium ion battery module according to the battery grid, the connecting piece grid, the flow field grid and the component grid size is realized by using the fluentmesh software.

Images