Simulation driving-based flow battery pile end plate design method
By optimizing the endplate of the flow battery stack using a simulation-driven design method, the problems of high weight and cost were solved, achieving lightweighting and cost reduction of the stack, and improving design efficiency and structural reliability.
Patent Information
- Application Number
- CN202511268830.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-06
- Publication Date
- 2025-12-19
AI Technical Summary
Existing flow battery stack endplate designs suffer from high weight and cost, and are deficient in lightweight design and refined cost control.
A simulation-driven design approach is adopted to optimize the structure of the fuel cell stack endplate by defining design variables, constructing a response surface model, performing topology optimization modeling, setting manufacturing feasibility constraints, conducting simulation verification and response surface fitting, thereby achieving lightweighting and cost reduction.
This effectively shortens the design cycle, reduces the overall weight of the fuel cell stack, lowers production costs, improves the structural reliability and manufacturing efficiency of the fuel cell stack, and achieves lightweight design of the fuel cell stack.
Smart Images
Figure CN121168031A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of flow battery stack endplate technology, and in particular to a simulation-driven flow battery stack endplate design method. Background Technology
[0002] A vanadium redox flow battery (VRB) is a redox battery in which the active material is in a circulating liquid state. The stack endplates are used to press and seal the multi-layer single-cell modules using fastening devices (such as screws). These endplates must withstand the pressure during stack assembly and the tightening pressure during operation to prevent leakage due to insufficient rigidity or localized plastic deformation failure due to insufficient strength. Furthermore, there is a risk of contact with the electrolyte. Therefore, the endplate materials tend to be rigid, low-deformation metal alloys or composite materials to ensure long-term stability.
[0003] The shortcomings of existing technologies lie in the fact that, in the past few years, the entire flow battery industry has focused on cost reduction driven by the industrial upgrading of core materials (membranes, carbon felts, bipolar plates) and the technological iteration of fuel cell stacks: optimizing flow channels, improving electrical density, and increasing electrolyte utilization. As a non-core component, the fuel cell stack endplate still adopts a bulky, cumbersome, and functional design philosophy. With technological advancements and policy support, my country's vanadium redox flow battery industry has entered the early stages of commercial operation. The resulting capacity release will create a virtuous cycle of "technological innovation - cost reduction - demand expansion." In terms of weight, the fuel cell stack endplate accounts for 30% to 40% of the total weight of the stack, and in terms of cost, it accounts for 5% to 8% of the stack cost. Lightweight design and refined cost control are essential for the future research and development of fuel cell stacks, and the design of flow battery stack endplates will become one of the core technical aspects of stack structural engineering.
[0004] In conclusion, the existing technology obviously has inconveniences and defects in practical use, so it is necessary to improve it. Summary of the Invention
[0005] To address the aforementioned shortcomings, the present invention aims to provide a simulation-driven design method for the endplate of a flow battery stack, thereby solving the problems of high weight and high cost associated with simulation-driven endplate design methods for flow battery stacks.
[0006] To achieve the above objectives, this invention provides a simulation-driven method for designing endplates of a flow battery stack, comprising the following steps:
[0007] Step 1: Define design variables and determine optimization objectives;
[0008] Step 2: Construct the response surface model of the central composite design;
[0009] Step 3: Prepare for topology optimization modeling based on each set of sample points;
[0010] Step 4: Define manufacturing feasibility constraints;
[0011] Step 5, build the topology space;
[0012] Step 6: Set the constraints for equivalent stress and displacement, and define the topology optimization objective;
[0013] Step 7: Determine whether the equivalent stress and deformation results calculated by the topology optimization target meet the constraints of equivalent stress and displacement set in Step 6; if not, proceed to Step 5; if yes, proceed to Step 8.
[0014] Step 8: Obtain the topology optimization objective result and convert it into a solid model.
[0015] Step 9: Determine whether the equivalent stress and deformation results of the entity model meet the constraints of equivalent stress and displacement set in Step 6; if not, further fit the topology optimization target result and the entity model, and then execute Step 8; if yes, execute Step 10.
[0016] Step 10: Obtain the final optimization result of the sample point; that is, the entity model obtained in step 8 is used as the final result of the response surface analysis for that sample point.
[0017] Step 11: Based on the solid model obtained in Step 10, extract the strength and stiffness simulation results data of the sample points, namely the deformation of the center point and corner points of the fuel cell stack end plate, and the maximum equivalent stress of the fuel cell stack end plate.
[0018] Step 12: Conduct cost analysis for mold casting of fuel cell stack end plates;
[0019] Step 13: Generate a dataset of response surface sample points;
[0020] Step 14: Response surface fitting and multi-objective optimization;
[0021] Step 15: Determine if the design is feasible for casting and production; if not, proceed to step 14; if yes, proceed to step 16.
[0022] Step 16 yields the lightweight fuel cell stack endplate structure scheme with the highest material utilization rate.
[0023] As a preferred technical solution, in step 1, the outer dimensions of the fuel cell stack plate frame, the position of the inlet and outlet liquid ports and the size of the inlet and outlet liquid ports are determined, and the preliminary position of the screw is established to create a preliminary flat plate structure for the fuel cell stack plate.
[0024] The stacking force and holding force of the fuel cell stack were calculated to determine the diameter of the screws, the number of screws and the screw spacing were preliminarily determined, and the number of screws and the screw spacing were used as design variables.
[0025] The weight and cost of the fuel cell stack endplates were used as optimization objectives.
[0026] As a preferred technical solution, the external dimensions of the fuel cell stack end plate are:
[0027] L×W×TR
[0028] Where L is the length, W is the width, T is the thickness, and R is the chamfer;
[0029] The initial position of the screw is the center line of the screw assembly hole outline;
[0030] Number of screws: The screws are located around the end plates of the fuel cell stack, so the number of screws N is: N = 2 × N L +2×N w
[0031] Where N represents the number of screws, N L N represents the number of screws along a single row length. w Indicates the number of screws in the width direction of a single column;
[0032] Screw pitch: includes the pitch L between adjacent screws along the length direction. i The spacing W between adjacent screws in the width direction j The number of screws includes the number N of screws along the length direction. L The number N of screws in the width direction w ;
[0033] The lightest weight of the fuel cell stack endplate is represented by Min(G). m The lowest cost is represented by Min(W).
[0034] As a preferred technical solution, step 2 involves constructing a response surface model of the central composite design, including the following steps:
[0035] (21) Determine the initial values of the design variables, and verify the step size and direction of each design variable through preliminary simulation;
[0036] Each design variable is configured with 6 to 8 sample points;
[0037] (22) The center point composite design consists of three parts:
[0038] Center point: All design variables are taken at the median level;
[0039] Cube points: used to estimate main effects and interactions; 16 cube points are required for the 4-factor model.
[0040] Star points: Set along the axes of each variable to estimate the coefficients of quadratic terms. For example, a 4-factor model requires 8 star points.
[0041] The total number of sample points is 25.
[0042] As a preferred technical solution, step 3, the preparation of the topology optimization numerical model, includes:
[0043] Based on each set of sample points, a geometric model is imported to ensure that the topology optimization model has no geometric defects.
[0044] Before preparing the topology optimization model, the maximum envelope space for topology optimization in the thickness direction of the fuel cell stack endplate is determined.
[0045] As a preferred technical solution, in step 4, the manufacturing feasibility constraints include: geometric boundaries and minimum unit size.
[0046] As a preferred technical solution, the steps for constructing the topology space in step 5 are as follows:
[0047] (51) Based on the geometric model, ensure that the design interface of the stack end plate is invariable and expand the thickness direction dimension to more than twice the original dimension;
[0048] (52) Assign materials and properties, and define material parameters;
[0049] (53) Assign the PSOLID attribute to the design area and the PMASS attribute to the non-design area;
[0050] PSOLID is the identifier for solid elements, used to define the type of 3D solid element; PMASS is the identifier for mass elements, used to define lumped mass elements.
[0051] (54) Set two working conditions, namely working condition and pressing condition;
[0052] (55) Apply load and constraint, constrain the contact surface of the bolt hole washer on the outer side of the stack end plate by SPC, and apply the stack pressure load P to the area of the inner side plate frame of the stack end plate.
[0053] As a preferred technical solution, in (55), the axial load Max(P)-Min(P) of each screw is ≤10%.
[0054] As a preferred technical solution, in step 6, constraints on equivalent stress and displacement are set, and a topology optimization objective is defined. The steps are as follows:
[0055] (61) Set the constraint conditions for equivalent stress: the equivalent stress σ of the fuel cell stack endplate under different operating conditions eqv ≤[σ], where [σ] represents the allowable stress;
[0056] (62) Displacement constraint: The displacement of the center point of the fuel cell stack end plate is less than L / 1000, where L is the length of the fuel cell stack end plate;
[0057] (63) Topology optimization design variables: cell density, default 0~1;
[0058] (64) Topology optimization objectives: lightest weight, maximum stiffness, and minimum volume fraction.
[0059] As a preferred technical solution, step 14 involves response surface fitting and multi-objective optimization, including the following steps:
[0060] (141) Test the model using analysis of variance, and require R0. 2 >0.9 to ensure reliability;
[0061] (142) Use multinomial regression or Kriging model to fit the relationship between input design variables and response;
[0062] (143) Through response surface analysis, the cost-optimal solution that satisfies the conditions of equivalent stress, stiffness and screw load difference is obtained.
[0063] This invention provides a simulation-driven method for designing endplates of flow battery stacks, which has the following advantages:
[0064] 1. By moving simulation verification from the traditional post-stage to the conceptual design stage, and integrating it throughout the entire process of scheme demonstration, preliminary design, and detailed design, the R&D and design cycle of fuel cell stacks is effectively shortened;
[0065] 2. By integrating response surface methodology and topology optimization, the endplates of the fuel cell stack can effectively reduce the overall weight of the stack while ensuring structural reliability, thus facilitating hoisting and transportation;
[0066] 3. Through topology optimization and model generation technology, the industrial design effect of the endplate is achieved by itself, eliminating the need for appearance design and packaging of the fuel cell stack, thus reducing the external promotion cost of industrial design in the market.
[0067] 4. It greatly reduces the trial production cost, and at the same time, the fuel cell stack is mass-produced and delivered. The end plate is finally realized through the casting process, which reduces the BOM cost of the fuel cell stack. Attached Figure Description
[0068] Figure 1 This is a flowchart of the simulation-driven design method for the endplate of a flow battery stack according to the present invention;
[0069] Figure 2 This is a schematic diagram of the end plate of the fuel cell stack. Detailed Implementation
[0070] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0071] Example 1:
[0072] See Figure 1 This invention provides a simulation-driven design method for the endplate of a flow battery stack, which moves simulation verification from the traditional post-stage to the conceptual design stage, running through the entire process of scheme demonstration, preliminary design, and detailed design, forming a closed-loop iterative mechanism of "design-simulation".
[0073] Specifically, it includes the following steps:
[0074] Step 1: Define design variables and determine optimization objectives.
[0075] Based on the dimensions of the fuel cell stack frame outline, the location and dimensions of the inlet and outlet liquid ports, the external dimensions of the fuel cell stack end plates and the preliminary position of the screws are determined, and a preliminary flat plate structure for the fuel cell stack end plates is established. A schematic diagram of the preliminary flat plate structure for the fuel cell stack end plates is shown below. Figure 2 As shown.
[0076] The dimensions of the fuel cell stack endplates are as follows:
[0077] L×W×TR
[0078] Where L is the length, W is the width, T is the thickness, and R is the chamfer.
[0079] The initial position of the screw is the center line of the screw assembly hole outline, with four screws connected end to end, forming a rectangular frame. The screw assembly consists of multiple screws. The center points of the multiple screws are connected sequentially to form the center line of the screw assembly hole outline.
[0080] Based on the preliminary flat plate structure of the fuel cell stack endplate, and combined with historical data on fuel cell stack loading, the stack loading force and holding force are calculated to determine the diameter of the screws, the number of screws and the screw spacing are preliminarily confirmed, and the number of screws and the screw spacing are used as design variables (i.e. factors).
[0081] Number of screws: The screws are located around the end plates of the fuel cell stack, so the number of screws N is: N = 2 × N L +2×N w
[0082] Where N represents the number of screws, N L N represents the number of screws along a single row length. w Indicates the number of screws in the width direction of a single column;
[0083] Screw pitch: includes the pitch L between adjacent screws along the length direction.i The spacing W between adjacent screws in the width direction j The number of screws includes the number N of screws along the length direction. L The number N of screws in the width direction w See Figure 2 . Figure 2 In the diagram, 1 represents the inlet / outlet liquid port, and 2 represents the center line of the screw assembly hole profile.
[0084] Spacing L between adjacent screws along the length direction i Where i is 12, 23, 34…(N) L -1)N L i = 12 indicates the first and second screws along the length direction; i = 23 indicates the second and third screws along the length direction, and so on, i = (N) L -1)N L Indicates the Nth direction along the length. L -1 screw and the Nth L Root screw.
[0085] Spacing W between adjacent screws in the width direction j Where j is 12, 23, 34…(N) w -1)N w ; j=12 indicates the first and second screws in the width direction; j=23 indicates the second and third screws in the width direction, and so on, j=(N) L -1)N L Indicates the Nth position in the width direction. w -1 screw and the Nth w Root screw.
[0086] The weight and cost of the fuel cell stack endplates are used as optimization objectives. Through optimization, the goal is to achieve the lightest weight and lowest cost for the fuel cell stack endplates. The lightest weight for the fuel cell stack endplates is represented as Min(G). m The lowest cost is represented by Min(W).
[0087] Step 2, construct the response surface model of the central composite design, including the following steps:
[0088] (21) Determine the initial values of the design variables and verify the step size and direction of each design variable through preliminary simulation.
[0089] Each design variable is set with 6 to 8 sample points.
[0090] (22) The center point composite design consists of three parts:
[0091] Center point: All design variables are taken at the median level;
[0092] Cube points: used to estimate main effects and interactions; 16 cube points are required for the 4-factor model.
[0093] Star points: Set along the axes of each variable to estimate the coefficients of the quadratic term. For example, a 4-factor model requires 8 star points.
[0094] The total number of sample points in this invention is 25.
[0095] Step 3, based on each set of sample points, prepare for topology optimization mathematical modeling; including:
[0096] For each set of sample points, import a geometric model (such as a CAD model) to ensure that the topology optimization model has no geometric defects;
[0097] Before preparing the topology optimization model, the maximum envelope space for topology optimization in the thickness direction of the fuel cell stack endplate is determined.
[0098] Step 4: Define manufacturing feasibility constraints.
[0099] Manufacturing feasibility constraints include: geometric boundaries and minimum unit size.
[0100] Transform the draft angle requirement into a geometric boundary condition to avoid the appearance of structures that cannot be demolded in the optimization results.
[0101] Define a minimum unit size to avoid designing small structures or regions. The unit size is preferably less than 1 / 5 of the minimum feature size.
[0102] Step 5, build the topology space. This includes the following steps:
[0103] (51) Based on the geometric model, ensure that the design interface of the stack end plate is invariable, and appropriately expand the thickness direction dimension to more than twice the original dimension.
[0104] (52) Assign materials and properties, and define material parameters.
[0105] Material parameters include elastic modulus, Poisson's ratio, and density.
[0106] (53) Assign the PSOLID attribute to the design area and the PMASS attribute to the non-design area;
[0107] PSOLID is the identifier for solid elements, used to define the type of 3D solid element; PMASS is the identifier for mass elements, used to define lumped mass elements.
[0108] (54) Set two working conditions, namely working condition and pressing condition.
[0109] (55) Apply loads and constraints (boundary conditions), constrain the contact surface of the bolt hole washer on the outer side of the stack end plate by SPC, and apply the stack pressure load P to the area of the inner side plate frame of the stack end plate.
[0110] The axial load of each screw, Max(P) - Min(P), is ≤10%.
[0111] Step 6: Set the constraints for equivalent stress and displacement, and define the topology optimization objective. The steps are as follows:
[0112] (61) Set the constraint conditions for equivalent stress: the equivalent stress σ of the fuel cell stack endplate under different operating conditions eqv ≤[σ], where [σ] represents the allowable stress;
[0113] (62) Displacement constraint: The displacement of the center point of the fuel cell stack end plate is less than L / 1000, where L is the length of the fuel cell stack end plate;
[0114] (63) Topology optimization design variables: cell density, default 0~1;
[0115] (64) Topology optimization objectives: lightest weight, maximum stiffness, and minimum volume fraction.
[0116] Step 7: Determine whether the equivalent stress and deformation results calculated by the topology optimization target meet the constraints of equivalent stress and displacement set in Step 6; if not, proceed to Step 5; if yes, proceed to Step 8.
[0117] Step 8: Obtain the topology optimization target result and convert it into a solid digital model; that is, reconstruct the equivalent stress and deformation results that meet the requirements, and convert them into a 3D digital model with similar shape and rounded size through design software;
[0118] The design software used in step 8 is existing technology. Examples include SpaceClaim, Solidworks, and UG.
[0119] Step 9: Determine whether the equivalent stress and deformation results of the entity model meet the constraints of equivalent stress and displacement set in Step 6; if not, further fit the topology optimization target result and the entity model, and then execute Step 8; if yes, execute Step 10.
[0120] Step 10: Obtain the final optimization result of the sample point; that is, the entity model obtained in step 8 is used as the final result of the sample point in the response surface analysis.
[0121] Step 11: Based on the solid model obtained in Step 10, extract the strength and stiffness simulation results data of the sample points, namely the deformation of the center point and corner points of the fuel cell stack end plate, and the maximum equivalent stress of the fuel cell stack end plate.
[0122] Step 12: Conduct mold casting cost analysis for fuel cell stack end plates. The mold casting cost analysis includes: material costs, which are directly related to the weight of the fuel cell stack end plates; and mold cost allocation.
[0123] Step 13: Generate a response surface sample point dataset.
[0124] The reaction forces at the bolt hole locations of each sample point were analyzed, and the axial loads Max(P)-Min(P) of each screw were statistically calculated.
[0125] All data from each sample point are collected and summarized to obtain the response surface sample point data.
[0126] Step 14, Response Surface Fitting and Multi-Objective Optimization. This includes the following steps:
[0127] (141) Test the model using analysis of variance (ANOVA), requiring R0 to be equal to the variance of the model. 2 >0.9 to ensure reliability;
[0128] (142) Use multinomial regression (such as a quadratic model) or Kriging model to fit the relationship between input design variables and response;
[0129] (143) Through response surface analysis, the cost-optimal solution that satisfies the conditions of equivalent stress, stiffness and screw load difference is obtained.
[0130] Step 15: Determine if the design is feasible for casting and production; if not, proceed to step 14; if yes, proceed to step 16.
[0131] Step 16 yields the lightweight fuel cell stack endplate structure scheme with the highest material utilization rate.
[0132] This invention provides a simulation-driven design method for endplates of flow battery stacks, reducing prototyping costs and enabling mass production and delivery of the stack, significantly lowering the stack's BOM cost. Through the fusion of response surface methodology and topology optimization, the endplates effectively reduce the overall weight of the stack while maintaining structural reliability, achieving lightweight design and facilitating subsequent hoisting and transportation. By moving simulation verification from the traditional later stage to the conceptual design phase, spanning the entire process from scheme demonstration and preliminary design to detailed design, the stack R&D and design cycle is effectively shortened by up to 50%. Through topology optimization and model generation technologies, the industrial design effect of the endplates is achieved, eliminating the need for external design and packaging of the stack, thus reducing the marketing costs associated with industrial design.
[0133] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.
Claims
1. A simulation-driven design method for endplates of a flow battery stack, characterized in that, Includes the following steps: Step 1: Define design variables and determine optimization objectives; Step 2: Construct the response surface model of the central composite design; Step 3: Prepare for topology optimization modeling based on each set of sample points; Step 4: Define manufacturing feasibility constraints; Step 5, build the topology space; Step 6: Set the constraints for equivalent stress and displacement, and define the topology optimization objective; Step 7: Determine whether the equivalent stress and deformation results calculated by the topology optimization target meet the constraints of equivalent stress and displacement set in Step 6; If not, proceed to step 5; If so, proceed to step 8; Step 8: Obtain the topology optimization objective result and convert it into a solid model. Step 9: Determine whether the results of the entity number simulation of the true equivalent stress and deformation meet the constraints of equivalent stress and displacement set in Step 6; If not, then after further fitting the topology optimization target result and the solid model, proceed to step 8; If so, proceed to step 10; Step 10: Obtain the final optimization result of the sample point; that is, the entity model obtained in step 8 is used as the final result of the response surface analysis for that sample point. Step 11: Based on the solid model obtained in Step 10, extract the strength and stiffness simulation results data of the sample points, namely the deformation of the center point and corner points of the fuel cell stack end plate, and the maximum equivalent stress of the fuel cell stack end plate. Step 12: Conduct cost analysis for mold casting of fuel cell stack end plates; Step 13: Generate a response surface sample point dataset; Step 14: Response surface fitting and multi-objective optimization; Step 15: Determine whether the design is feasible for casting and production; If not, proceed to step 14; if yes, proceed to step 16. Step 16 yields the lightweight fuel cell stack endplate structure scheme with the highest material utilization rate.
2. The simulation-driven design method for endplates of a flow battery stack according to claim 1, characterized in that, In step 1, based on the dimensions of the outer contour of the fuel cell stack frame, the position and size of the inlet and outlet liquid ports, the outer dimensions of the fuel cell stack end plate and the initial position of the screw are determined, and the initial flat plate structure of the fuel cell stack end plate is established. The stacking force and holding force of the fuel cell stack were calculated to determine the diameter of the screws, the number of screws and the screw spacing were preliminarily determined, and the number of screws and the screw spacing were used as design variables. The weight and cost of the fuel cell stack endplates were used as optimization objectives.
3. The simulation-driven design method for endplates of a flow battery stack according to claim 2, characterized in that, The dimensions of the fuel cell stack endplates are as follows: L×W×TR Where L is the length, W is the width, T is the thickness, and R is the chamfer; The initial position of the screw is the center line of the screw assembly hole outline; Number of screws: The screws are located around the end plates of the fuel cell stack, so the number of screws N is: N = 2 × N L +2×N w Where N represents the number of screws, N L N represents the number of screws along a single row length direction. w Indicates the number of screws in the width direction of a single column; Screw pitch: includes the pitch L between adjacent screws along the length direction. i The spacing W between adjacent screws in the width direction j The number of screws includes the number N of screws along the length direction. L The number N of screws in the width direction w ; The lightest weight of the fuel cell stack endplate is represented by Min(G). m The lowest cost is represented by Min(W).
4. The simulation-driven design method for endplates of a flow battery stack according to claim 1, characterized in that, Step 2 involves constructing the response surface model of the central composite design, including the following steps: (21) Determine the initial values of the design variables, and verify the step size and direction of each design variable through preliminary simulation; Each design variable is configured with 6 to 8 sample points; (22) The center point composite design consists of three parts: Center point: All design variables are taken at the median level; Cube points: used to estimate main effects and interactions; 16 cube points are required for the 4-factor model. Star points: Set along the axes of each variable to estimate the coefficients of quadratic terms. For example, a 4-factor model requires 8 star points. The total number of sample points is 25.
5. The simulation-driven design method for endplates of a flow battery stack according to claim 1, characterized in that, Step 3, the preparation of the topology optimization numerical model includes: Based on each set of sample points, a geometric model is imported to ensure that the topology optimization model has no geometric defects. Before preparing the topology optimization model, the maximum envelope space for topology optimization in the thickness direction of the fuel cell stack endplate is determined.
6. The simulation-driven design method for endplates of a flow battery stack according to claim 1, characterized in that, In step 4, the manufacturing feasibility constraints include: geometric boundaries and minimum unit size.
7. The simulation-driven design method for endplates of a flow battery stack according to claim 1, characterized in that, In step 5, the steps for constructing the topology space are as follows: (51) Based on the geometric model, ensure that the design interface of the stack end plate is invariable and expand the thickness direction dimension to more than twice the original dimension; (52) Assign materials and properties, and define material parameters; (53) Assign the PSOLID attribute to the design area and the PMASS attribute to the non-design area; PSOLID is the identifier for solid elements, used to define the type of 3D solid element; PMASS is the identifier for mass elements, used to define lumped mass elements. (54) Set two working conditions, namely working condition and pressing condition; (55) Apply load and constraint, constrain the contact surface of the bolt hole washer on the outer side of the stack end plate by SPC, and apply the stack pressure load P to the area of the inner side plate frame of the stack end plate.
8. The simulation-driven design method for endplates of a flow battery stack according to claim 7, characterized in that, In (55), the axial load Max(P)-Min(P) of each screw is ≤10%.
9. The simulation-driven design method for endplates of a flow battery stack according to claim 1, characterized in that, In step 6, constraints on equivalent stress and displacement are set, and the topology optimization objective is defined. The steps are as follows: (61) Set the constraint conditions for equivalent stress: the equivalent stress σ of the fuel cell stack endplate under different operating conditions eqv ≤[σ], where [σ] represents the allowable stress; (62) Displacement constraint: The displacement of the center point of the fuel cell stack end plate is less than L / 1000, where L is the length of the fuel cell stack end plate; (63) Topology optimization design variables: cell density, default 0~1; (64) Topology optimization objectives: lightest weight, maximum stiffness, and minimum volume fraction.
10. The simulation-driven design method for endplates of a flow battery stack according to claim 1, characterized in that, Step 14, perform response surface fitting and multi-objective optimization, including the following steps: (141) Test the model using analysis of variance, and require R0. 2 >0.9 to ensure reliability; (142) Use multinomial regression or Kriging model to fit the relationship between input design variables and response; (143) Through response surface analysis, the cost-optimal solution that satisfies the conditions of equivalent stress, stiffness and screw load difference is obtained.