Three-dimensional simulation design method and system for ball valve

Abstract

The invention relates to the technical field of ball valve design and simulation, in particular to a three-dimensional simulation design method and system for a ball valve. The method comprises the following steps: performing reference geometric construction based on a ball valve design specification, and performing geometric parameterization to obtain an initial geometric configuration; importing the initial geometric configuration into a finite element analysis platform, and endowing material attributes to obtain a finite element mesh model; performing ball valve working stress analysis on the finite element mesh model to obtain a stress-strain field; performing model fluid domain grid division according to the initial geometric configuration and the stress-strain field to obtain a fluid domain grid; valve opening change setting is conducted on the fluid domain grids, and a CFD calculation model is obtained; internal flow field transient simulation of the ball valve under different opening degrees is conducted on the CFD calculation model, and fluid dynamic parameters are obtained. The dynamic characteristics of the valve under the complex working conditions are accurately captured, and the working performance of the valve under different working conditions is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of ball valve design and simulation, and particularly to a three-dimensional simulation design method and system for ball valves. Background Art

[0002] As a fluid control device, ball valves are widely used in industries such as petroleum, chemical, natural gas, and water treatment. Especially in pipeline systems with high pressure, high temperature, and corrosive fluids, extremely high requirements are placed on their performance and reliability. Traditional ball valve design mainly relies on empirical formulas, simplified models, and physical experiments. However, with the increasing complexity of industrial systems and the extremeization of operating conditions, these methods have gradually revealed limitations. In order to improve design accuracy and efficiency, three-dimensional simulation design methods have gradually become a research hotspot.

[0003] Existing methods still have some limitations. For example, in simplified models, the accuracy is insufficient. To reduce the computational amount, the geometric model of the ball valve is usually simplified, and some small features such as chamfers and sealing grooves are ignored. These simplifications will affect the simulation accuracy, especially when evaluating performance parameters such as leakage rate.

[0004] Existing methods ignore the thermal-fluid-solid coupling. Temperature changes will affect the physical properties of fluids and solids and cause thermal stress and deformation. Ignoring the thermal-fluid-solid coupling effect will reduce the simulation accuracy, especially under extreme temperature conditions.

[0005] The transient operating conditions are ignored. The opening and closing processes of ball valves are dynamic processes, and the flow field and temperature field will change with time. Most existing simulation methods only perform steady-state simulations and cannot capture the transient characteristics. Summary of the Invention

[0006] Based on this, it is necessary to provide a three-dimensional simulation design method and system for ball valves to solve at least one of the above technical problems.

[0007] To achieve the above object, a three-dimensional simulation design method for ball valves includes the following steps:

[0008] Step S1: Construct a benchmark geometry based on the ball valve design specifications to obtain a preliminary geometric model; perform geometric parameterization on the preliminary geometric model to obtain an initial geometric configuration;

[0009] Step S2: Import the initial geometric configuration into a finite element analysis platform, assign material properties to obtain a finite element mesh model; perform a working stress analysis of the ball valve on the finite element mesh model to obtain a stress-strain field;

[0010] Step S3: Perform mesh generation for the model fluid domain based on the initial geometric configuration and stress-strain field to obtain the fluid domain mesh; set the valve opening change for the fluid domain mesh to obtain the CFD calculation model; perform transient simulation of the internal flow field of the ball valve at different openings for the CFD calculation model to obtain the hydrodynamic parameters;

[0011] Step S4: Perform transient thermal-fluid-solid coupling solution for the CFD calculation model and the finite element mesh model to obtain the transient temperature field and heat flux field; calculate the thermal stress based on the transient temperature field, heat flux field and stress-strain field to obtain the total stress field; perform extreme thermomechanical performance evaluation based on the transient temperature field, heat flux field and total stress field to obtain the thermomechanical performance index;

[0012] Step S5: Perform multi-objective robust optimization based on the thermomechanical performance index, hydrodynamic parameters and stress-strain field to obtain the optimized design scheme of the ball valve.

[0013] Through following the design specifications and establishing a parametric model, the present invention realizes the efficient and accurate construction of the geometric model of the ball valve, and provides a flexible and adjustable geometric basis for subsequent simulation analysis and optimization design. Parametric design makes design modification and scheme iteration very convenient, greatly improving the design efficiency. At the same time, it ensures that the designed ball valve meets industry standards and safety requirements, avoiding design defects and potential safety hazards. By importing the CAD model into the finite element analysis platform, and performing material property assignment, mesh generation, boundary condition application and solution, the stress, strain and displacement distributions of the ball valve under the maximum working pressure are obtained. This information can be used to evaluate the structural strength of the ball valve, identify potential weak links, and provide key input data for subsequent fluid-structure interaction analysis, thermal stress analysis and optimization design. By extracting the fluid domain, considering structural deformation, performing mesh generation, setting the valve opening change and other operations, a CFD calculation model capable of simulating the dynamic opening / closing process of the ball valve is established. The application of the dynamic mesh technology enables the CFD simulation to capture the transient changes of the flow field with the valve movement, and obtain the hydrodynamic parameters (such as flow coefficient, pressure drop, turbulence characteristics, etc.) at different opening degrees, providing an important basis for evaluating the flow performance of the valve and optimizing the design. By performing transient thermal-fluid-structure coupling solution, the temperature field, heat flux field and total stress field of the ball valve under extreme temperature conditions are obtained. This coupling analysis takes into account fluid flow, solid heat transfer and their interaction, and can more accurately simulate the real behavior of the ball valve under thermal conditions. The evaluation of the extreme temperature and mechanical properties based on these data provides a comprehensive basis for evaluating the thermodynamic performance of the valve, predicting the risk of thermal fatigue and optimizing the thermal design. By defining the optimization objectives and constraints, selecting the optimization algorithm, constructing the surrogate model, performing iterative optimization and simulation verification, an optimized design scheme of the ball valve that meets the design requirements and performance indicators is finally obtained. The application of the multi-objective optimization method enables the design scheme to achieve the best balance among multiple performance indicators (such as pressure drop, stress, fatigue life), improving the comprehensive performance and reliability of the ball valve. The use of the surrogate model greatly improves the optimization efficiency, enabling the optimization design to be completed within an acceptable time. Therefore, the present invention provides a three-dimensional simulation design method for ball valves. Through high-fidelity parametric models, fluid-structure coupling and transient simulation, it accurately captures the dynamic characteristics of the valve under complex working conditions, and combines thermal-fluid-structure coupling analysis and multi-objective robust optimization to effectively improve the design accuracy and efficiency of the ball valve, and finally obtain a robust design scheme that maintains excellent performance under various working conditions.

[0014] Preferably, step S1 includes the following steps:

[0015] Step S11: Obtain the design specifications of the ball valve, and define the design variables to obtain a design variable table;

[0016] Step S12: Construct a baseline geometry according to the design variable table to obtain a preliminary geometry model;

[0017] Step S13: Add detailed features to the preliminary geometry model to obtain a complete geometry model;

[0018] Step S14: Establish a parameter association between the complete geometry model and the design variable table to obtain a parametric geometry model;

[0019] Step S15: Validate and export the parametric geometry model to obtain an initial geometric configuration.

[0020] The present invention guides the design by obtaining and relying on authoritative ball valve design specifications (such as API 6D, ASME B16.34), ensuring that the designed ball valve meets industry standards and safety requirements, and avoiding potential safety hazards and performance defects caused by non-standard designs. At the same time, by defining design variables and establishing a design variable table, the design intent is clearly recorded in a structured and tabular form, providing clear input and basis for subsequent geometric modeling and parametric design, improving the orderliness and traceability of the design process, and laying a foundation for subsequent optimization design. Based on the initial values in the design variable table, the basic geometric shapes of the ball valve are quickly constructed using the basic geometric modeling functions of CAD software (such as extrusion, rotation), avoiding the cumbersome and time-consuming process of modeling from scratch and improving the modeling efficiency. The preliminary geometry model provides a basic framework for subsequent detail addition and parametric design, ensuring that the basic geometric proportions and functional requirements of the valve are met. Detail features such as flanges, bolt holes, valve stem holes, and sealing grooves are added to the preliminary geometry model, making the model more completely reflect the structure of the actual ball valve and providing more accurate geometric input for subsequent simulation analysis. As much as possible, the dimensions and positions of these detail features are parameterized, providing greater flexibility and adjustable space for subsequent parametric design and optimization design. By establishing a parameter association between the complete geometry model and the design variable table, full parametric control of the model geometry is achieved. This means that by simply modifying the parameter values in the design variable table, the geometry of the model can be automatically updated, greatly improving the flexibility and modification efficiency of the design. The establishment of parameter associations and constraint relationships ensures the rationality and consistency of the design, avoiding geometric errors and design conflicts caused by manual modification. By modifying the parameter values in the design variable table to verify the model, it is ensured that the model can be updated correctly and stably when the parameters change, guaranteeing the robustness and reliability of the model. The verified model is exported in a common format (such as STEP), providing a unified and standard geometric input for subsequent finite element analysis and computational fluid dynamics analysis, realizing seamless connection between the CAD model and simulation analysis, and improving the overall efficiency of the design process.

[0021] Preferably, step S2 includes the following steps:

[0022] Step S21: Import the initial geometric configuration into finite element analysis software to obtain the imported geometric model;

[0023] Step S22: Define the material properties for the imported geometric model to obtain the material property assignment model;

[0024] Step S23: Perform mesh division on the material property assignment model to obtain the finite element mesh model;

[0025] Step S24: Apply boundary conditions to the finite element mesh model to obtain the loading constraint model;

[0026] Step S25: Solve and post-process the loading constraint model to obtain the stress-strain field.

[0027] In the present invention, by importing the CAD model (initial geometric configuration) into finite element analysis software in a general format (such as STEP), seamless data conversion between design and analysis is achieved, avoiding the work of repeated modeling and improving work efficiency. The imported geometric model is checked and repaired (if necessary) to ensure the integrity and accuracy of the geometric model, providing a reliable basis for subsequent finite element analysis. Assigning correct material properties (such as elastic modulus, Poisson's ratio, density, etc.) to different components of the ball valve (valve body, ball, seat, valve stem, etc.) is a prerequisite for accurate finite element analysis. By selecting standard materials or manually inputting material parameters in the software, it is ensured that the material data used in the simulation analysis is consistent with the actual ball valve material, thereby improving the credibility of the simulation results. Discretizing the continuous geometric model into a finite number of elements and nodes is a necessary step for finite element analysis. By selecting an appropriate mesh type (such as tetrahedron), setting global and local mesh sizes, and performing mesh quality inspection and optimization, a high-quality finite element mesh is generated. A high-quality mesh can capture stress concentration and deformation more accurately, improve simulation accuracy, and avoid calculation errors or non-convergence caused by poor mesh quality. Applying boundary conditions consistent with the actual working conditions (such as fixed constraints, pressure loads, contact relationships, etc.) to the finite element model is the key to simulating the true stress state of the ball valve. By accurately defining these boundary conditions, the simulation model can reflect the true stress situation of the ball valve in the working state, thereby obtaining more realistic simulation results. By calculating the response (stress, strain, displacement) of the model under the given boundary conditions through a finite element solver, key information such as the stress distribution and deformation of the ball valve under the maximum working pressure is obtained. This information can be used to evaluate whether the structural strength of the ball valve meets the design requirements and identify potential weak links. The exported stress-strain field data provides important input for subsequent fluid-structure interaction analysis, thermal stress analysis, and optimization design.

[0028] Preferably, the model fluid domain mesh generation described in step S3 includes:

[0029] Performing fluid domain extraction on the initial geometric configuration to obtain a fluid domain geometric model;

[0030] Mapping the node displacement data in the stress-strain field to the boundary of the fluid domain geometric model, performing fluid domain update considering deformation, and obtaining the deformed fluid domain;

[0031] Performing fluid domain mesh generation on the deformed fluid domain to obtain a fluid domain mesh.

[0032] In the present invention, by extracting the region of fluid flow from the CAD model of the ball valve (i.e., subtracting entities such as the sphere, valve stem, and valve seat from the valve inner cavity), a geometric model dedicated to CFD simulation is created. This fluid domain geometric model accurately represents the fluid flow space inside the valve, avoids using a complete model containing solid components in CFD simulation, simplifies the calculation, and improves the efficiency. At the same time, it ensures that the fluid domain boundary is completely fitted to the inner surface of the solid component, laying a foundation for subsequent fluid-structure interaction analysis. Applying the deformation information (node displacement) of the valve under pressure obtained from the structural analysis to the fluid domain model enables the shape of the fluid domain to reflect the true flow passage shape of the valve under actual working conditions. This approach considering the influence of structural deformation on the flow field embodies the idea of fluid-structure interaction, improves the accuracy of CFD simulation, especially for ball valves under high-pressure and large-deformation conditions. Performing mesh generation on the updated fluid domain generates a mesh suitable for CFD calculation. By selecting an appropriate mesh type (such as polyhedral mesh), generating a prism layer mesh near the wall surface, and performing local mesh refinement in key regions, the obtained fluid domain mesh can accurately capture complex flow phenomena such as velocity gradients and flow separation in the boundary layer, thereby improving the accuracy and reliability of CFD simulation.

[0033] Preferably, the valve opening change setting described in step S3 includes:

[0034] Obtaining the valve type and control parameters, and defining the valve opening change curve to obtain valve opening change data;

[0035] Defining the dynamic mesh region according to the valve opening change data and the fluid domain mesh, and defining the valve opening movement mode of the ball valve to obtain the dynamic mesh movement setting;

[0036] Updating the dynamic mesh parameters according to the dynamic mesh movement setting and the fluid domain mesh to obtain a CFD calculation model.

[0037] The present invention provides accurate valve motion information for CFD simulation by specifying the valve type (rotary ball valve) and control parameters (rotation angle), and defining the variation curve of the valve opening with time (such as linear variation). The opening variation curve is discretized into a series of time points and corresponding opening values, enabling the CFD solver to accurately update the geometric position of the valve at each time step, thereby realizing the simulation of the dynamic opening or closing process of the valve. By dividing the fluid domain into a rigid body motion region (including the sphere and the valve stem) and a deformation region, and defining their motion modes respectively, an accurate simulation of the rotary motion of the ball valve is achieved. The setting of the rigid body rotation region ensures that the sphere can rotate according to the predefined opening curve, while the setting of the deformation region allows the mesh to be adaptively adjusted when the sphere moves, avoiding calculation errors caused by mesh distortion. The application of the dynamic mesh technology enables the CFD simulation to capture the transient changes in the flow field during the opening or closing process of the valve. Updating the mesh according to the dynamic mesh settings at each time step ensures that the CFD calculation is always carried out on the correct geometric model. The initialization and update of the dynamic mesh parameters ensure that the CFD solver can accurately track the motion of the valve throughout the simulation process, thereby obtaining reliable transient flow field data. The CFD calculation model including the dynamic mesh parameters provides complete inputs for subsequent transient flow field simulation and thermal-fluid-solid coupling analysis.

[0038] Preferably, the transient simulation of the internal flow field of the ball valve at different openings in step S3 includes:

[0039] Initialize the flow field of the CFD calculation model to obtain initial flow field data;

[0040] Calculate the rotation matrix of the sphere within each time step based on the initial flow field data, and perform fluid domain partitioning to obtain dynamic mesh data;

[0041] Perform transient flow field calculation based on the dynamic mesh data and the initial flow field data to obtain transient flow field data;

[0042] Calculate the turbulence parameters based on the transient flow field data and the dynamic mesh data to obtain turbulence characteristic data;

[0043] Perform valve flow performance analysis based on the turbulence characteristic data and the transient flow field data to obtain valve performance indicators;

[0044] Perform post-processing of the flow field data based on the valve performance indicators, the turbulence characteristic data, and the transient flow field data to obtain hydrodynamic parameters.

[0045] By providing a reasonable initial state for CFD simulation, the present invention avoids calculation instability or errors caused by unreasonable initial conditions. By setting fluid properties (such as density, viscosity), boundary conditions (such as inlet pressure, outlet pressure), and initial flow field velocity (such as stationary), the CFD solver can start the calculation from a physically reasonable state, improving the calculation convergence and efficiency. The position of the sphere is accurately updated at each time step, realizing the simulation of the dynamic opening or closing process of the ball valve. The calculation of the rotation matrix ensures that the sphere rotates according to the predefined opening curve, while the application of the fluid domain partition processing and mesh deformation algorithm ensures that the mesh maintains good quality during the movement of the sphere, avoiding calculation errors caused by mesh distortion. The generation of dynamic mesh data provides an accurate geometric model for the transient flow field calculation at each time step. By solving the Navier-Stokes equations at each time step, the flow field information (such as velocity, pressure) of the ball valve at different openings is obtained. Transient calculation can capture the change of the flow field over time, especially the unsteady flow phenomenon during the opening or closing process of the valve. These transient flow field data provide a basis for subsequent turbulent parameter calculation, valve performance analysis, and thermal-fluid-solid coupling analysis. By calculating turbulent parameters such as turbulent kinetic energy, turbulent dissipation rate, and turbulent viscosity, the turbulent intensity and distribution of the flow field at different openings are reflected. The application of the turbulence model enables the CFD simulation to more accurately predict turbulent flow, especially for flows with high Reynolds numbers and complex geometries. The turbulent characteristic data provide an important reference for valve flow performance analysis and optimization design. By calculating key parameters such as flow coefficient and pressure drop, the flow performance of the ball valve at different openings is quantified. These performance indicators can be used to evaluate whether the valve design meets the requirements of flow control and identify potential flow problems (such as excessive pressure drop, vortex, flow separation, etc.). The valve performance indicators provide a clear goal and basis for the optimization design of the valve. By visualizing the calculation results in the form of charts, contour maps, etc., the flow field information becomes more intuitive and understandable. The extraction and collation of fluid dynamics parameters provide comprehensive data support for valve performance evaluation, optimization design, and comparison with other design schemes. These parameters also provide the necessary input for subsequent thermal-fluid-solid coupling analysis.

[0046] Preferably, the transient thermal-fluid-solid coupling solution described in step S4 includes:

[0047] Defining the thermal boundary conditions for the CFD calculation model to obtain a thermally loaded CFD model;

[0048] Performing thermal coupling setting at the fluid-solid interface for the thermally loaded CFD model and the finite element mesh model to obtain a coupled calculation model;

[0049] Dividing the calculation domain of the coupled calculation model and performing time step size adaptive processing to obtain a set of coupled calculation parameters;

[0050] Set the initial conditions of multiple physical fields according to the coupling calculation parameter set to obtain the initial state of multiple physical fields;

[0051] Perform fluid domain heat flow coupling calculation based on the initial state of multiple physical fields to obtain the fluid temperature velocity field;

[0052] Perform interface heat exchange calculation based on the fluid temperature velocity field to obtain interface heat exchange data;

[0053] Perform solid domain temperature stress field calculation based on the interface heat exchange data to obtain the solid temperature stress field;

[0054] Perform coupling convergence evaluation and iterative control based on the fluid temperature velocity field, solid temperature stress field and interface heat exchange data to obtain the coupling iteration state;

[0055] Perform time advancement and result integration based on the fluid temperature velocity field, solid temperature stress field and coupling iteration state to obtain the transient temperature field and heat flow field.

[0056] By introducing the thermal effect into the CFD model, the CFD simulation can consider the influence of temperature on fluid flow. By setting thermal boundary conditions such as the fluid inlet temperature, ambient temperature, and convective heat transfer coefficient, the working state of the ball valve under actual thermal conditions is simulated, providing more realistic boundary conditions for subsequent thermal-fluid-solid coupling analysis. Connecting the fluid domain and the solid domain thermodynamically enables two-way heat transfer between the fluid and the solid. This coupling setting allows the simulation to simultaneously consider fluid flow, solid heat transfer, and their interactions, more comprehensively simulating the behavior of the ball valve under thermal conditions. Dividing the entire computational domain into a fluid domain and a solid domain and setting appropriate time steps respectively improves the computational efficiency. The time step adaptive processing can automatically adjust the time step according to the temperature change rates of the fluid and the solid, reducing the computational time while ensuring the computational accuracy. Determining the coupled calculation parameter set provides a unified setting for subsequent multi-physics field coupling calculations. Providing a reasonable initial state for the coupled calculation avoids computational instability or errors caused by unreasonable initial conditions. By setting the initial temperatures of the fluid and the solid, the initial velocity and pressure of the fluid, and the initial stress of the solid, the simulation can start from a state close to the actual situation, improving the convergence and accuracy of the calculation. Solving the Navier-Stokes equation and the energy equation simultaneously obtains the velocity, pressure, and temperature distributions of the fluid considering the temperature influence. This thermal-fluid coupling calculation can more accurately simulate the flow and heat transfer processes of the fluid inside the valve, especially for working conditions with high temperature, high pressure, or large temperature differences. Calculating the heat flux density and total heat exchange amount on the fluid-solid interface quantifies the heat transfer between the fluid and the solid. These data provide accurate boundary conditions for the heat conduction calculation in the solid domain and are the key to realizing thermal-fluid-solid coupling. Calculating the temperature distribution and thermal stress of the solid under thermal loads. By solving the heat conduction equation and the thermoelastic equation, the temperature changes and stress concentration conditions of each component of the valve under thermal conditions are obtained. These data are crucial for evaluating the structural strength and thermal fatigue life of the valve. Ensuring the accuracy of heat transfer and temperature field calculation between the fluid domain and the solid domain. Through iterative calculation until the differences in fluid temperature, solid temperature, and interface heat flux density between two iterations are less than the set value, the convergence and accuracy of the coupled calculation are ensured. By repeating the above coupled calculation process at each time step, the changes in the temperature field, heat flux field, and stress field of the ball valve during the entire transient process are obtained. These data comprehensively reflect the dynamic behavior of the ball valve under thermal conditions and provide an important basis for evaluating the thermodynamic performance of the valve and optimizing the design.

[0057] Preferably, the extreme temperature thermodynamic performance evaluation described in step S4 includes:

[0058] Performing thermodynamic performance evaluation based on the transient temperature field, heat flux field, and total stress field to obtain thermodynamic performance indicators;

[0059] Identify and extract key hot spot areas based on the transient temperature field, heat flux field, and total stress field to obtain key thermodynamic region data;

[0060] Quantitatively calculate thermal performance parameters based on the key thermodynamic region data to obtain a set of thermal performance parameters;

[0061] Evaluate thermal stress intensity and thermal fatigue based on the total stress field, transient temperature field, heat flux field, and key thermodynamic region data to obtain thermal fatigue risk assessment data;

[0062] Analyze the transient temperature response curve based on the transient temperature field, heat flux field, and key thermodynamic region data to obtain a set of temperature response characteristic curves;

[0063] Analyze the influence of thermal deformation on the sealing performance based on the transient temperature field, heat flux field, total stress field, and thermal fatigue risk assessment data to obtain thermal sealing performance assessment data;

[0064] Construct comprehensive performance indicators for the set of thermal performance parameters, thermal fatigue risk assessment data, temperature response characteristic curve set, and thermal sealing performance assessment data to obtain thermodynamic performance indicators.

[0065] Through summarizing the entire thermodynamic performance evaluation process, by comprehensively analyzing the transient temperature field, heat flux field, and total stress field data, a set of indicators that can quantitatively characterize the performance of the ball valve under extreme temperature conditions is obtained. These indicators provide a comprehensive basis for evaluating the thermodynamic performance of the valve and guiding the optimization design. By identifying and extracting the data of high-temperature, high heat flux density, and high-stress regions, the analysis focus is concentrated on the parts of the valve that are most prone to failure. This targeted analysis method improves the efficiency and accuracy of the evaluation and provides key data for subsequent calculation of thermal performance parameters, thermal stress evaluation, and thermal fatigue analysis. By calculating parameters such as the average temperature, maximum temperature, maximum heat flux density, and maximum stress in the key regions, the thermal performance of the valve under extreme temperature conditions is quantified. These parameters provide a direct basis for evaluating whether the thermal design of the valve is reasonable and whether there are risks of overheating or excessive stress. By evaluating whether the thermal stress exceeds the strength limit of the material and the fatigue life under cyclic temperature loads, the possibility of valve failure under extreme temperature conditions is predicted. The thermal fatigue risk assessment data provides an important reference for optimizing the valve design, selecting suitable materials, and formulating reasonable operation and maintenance strategies. By analyzing the temperature change curve of the key region over time, the temperature response characteristics of the valve under transient thermal loads, such as the heating rate and the time to reach the steady state, are understood. This information helps to evaluate the adaptability of the valve under rapid temperature change conditions and provides a basis for optimizing the valve structure and improving the control strategy. By analyzing the influence of thermal deformation on the sealing gap between the valve seat and the ball, the sealing performance of the valve under extreme temperature conditions is evaluated. The thermal sealing performance assessment data provides key information for optimizing the valve sealing structure, selecting suitable sealing materials, and predicting the leakage risk. By integrating the evaluation results of multiple aspects, a set of comprehensive indicators that can comprehensively reflect the thermodynamic performance of the valve is formed. These indicators provide a more intuitive and comprehensive basis for comparing the advantages and disadvantages of different design schemes, guiding the optimization design, and evaluating the overall performance of the valve.

[0066] Preferably, step S5 includes the following steps:

[0067] Step S51: Define the optimization objectives and constraints based on the thermodynamic performance indicators, fluid dynamics parameters, and stress-strain field to obtain the optimization objective and constraint problem;

[0068] Step S52: Select the optimization algorithm and set the parameters according to the optimization objective and constraint problem to obtain the optimization algorithm configuration;

[0069] Step S53: Construct a surrogate model according to the optimization objective and constraint problem to obtain the surrogate model;

[0070] Step S54: Perform optimization iteration and simulation verification according to the surrogate model and the optimization algorithm configuration to obtain the optimization process data;

[0071] Step S55: Select an optimization solution for the optimized process data to obtain an optimized design solution for the ball valve.

[0072] In the present invention, by transforming the design requirements of the ball valve into a clear mathematical optimization problem, a clear direction and goal are provided for subsequent optimized design. By defining optimization objectives (such as minimizing pressure drop, minimizing maximum stress, maximizing fatigue life) and constraint conditions (such as geometric dimension range, maximum stress, minimum wall thickness), it is ensured that the optimized design solution can not only meet the performance requirements but also conform to engineering practice and specification requirements. An algorithm suitable for solving multi-objective optimization problems (such as NSGA-II) is selected, and algorithm parameters are set according to the problem characteristics and experience. Reasonable algorithm selection and parameter setting can improve the optimization efficiency, find the optimal solution or a solution set close to the optimal solution more quickly, and avoid blind search or falling into local optimum. By constructing a surrogate model (such as a radial basis function network) to approximately simulate the performance of the ball valve, the computational cost in the optimization process is greatly reduced. The use of the surrogate model avoids time-consuming CFD and FEA simulations for each iteration, enabling the optimization process to be completed within an acceptable time and improving the efficiency of optimized design. Combining the surrogate model with the optimization algorithm realizes the automatic optimization of the design parameters of the ball valve. Through iterative calculations, the algorithm continuously explores the design space to find a better design solution. At the same time, excellent individuals are verified regularly with CFD and FEA simulations, and the surrogate model is updated to ensure the reliability of the optimization results. Recording the optimization process data provides a basis for subsequent solution selection and analysis. From a set of Pareto optimal solutions obtained by the optimization algorithm, one or more best design solutions that meet the performance requirements are selected according to the design requirements and priorities. Through re-verification with CFD and FEA simulations, the reliability of the selected solution is ensured. The finally obtained optimized design solution for the ball valve realizes the optimization of performance indicators (such as pressure drop, stress, fatigue life) under the premise of meeting the constraint conditions, improving the comprehensive performance and reliability of the ball valve.

[0073] Preferably, the present invention also provides a three-dimensional simulation design system for a ball valve, which is used to execute the three-dimensional simulation design method for a ball valve as described above. The three-dimensional simulation design system for a ball valve includes:

[0074] A geometric parameterization modeling module, which is used to construct a benchmark geometry based on the ball valve design specification to obtain a preliminary geometric model; perform geometric parameterization on the preliminary geometric model to obtain an initial geometric configuration;

[0075] A static structural analysis module, which is used to import the initial geometric configuration into a finite element analysis platform, assign material properties to obtain a finite element mesh model; perform a working stress analysis of the ball valve on the finite element mesh model to obtain a stress-strain field;

[0076] A transient flow field simulation module, which is used to perform mesh generation for the model fluid domain according to the initial geometric configuration and stress-strain field to obtain the fluid domain mesh; set the valve opening change for the fluid domain mesh to obtain a CFD calculation model; perform transient simulation of the internal flow field of the ball valve at different openings on the CFD calculation model to obtain hydrodynamic parameters;

[0077] A coupled thermodynamics analysis module, which is used to perform transient thermal-fluid-solid coupling solution on the CFD calculation model and the finite element mesh model to obtain the transient temperature field and heat flow field; calculate the thermal stress according to the transient temperature field, heat flow field and stress-strain field to obtain the total stress field; perform extreme temperature thermomechanical performance evaluation according to the transient temperature field, heat flow field and total stress field to obtain thermomechanical performance indicators;

[0078] A multi-objective robust optimization module, which is used to perform multi-objective robust optimization according to the thermomechanical performance indicators, hydrodynamic parameters and stress-strain field to obtain an optimized design scheme for the ball valve. Description of the Drawings

[0079] Figure 1 It is a schematic diagram of the step flow of a three-dimensional simulation design method for a ball valve;

[0080] Figure 2 It is a schematic diagram of the detailed implementation steps of step S2 in the present invention.

[0081] The realization of the purpose, functional characteristics and advantages of the present invention will be further described in conjunction with the embodiments with reference to the drawings. Specific Embodiments

[0082] The technical method of the present invention will be clearly and completely described below with reference to the drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0083] In addition, the drawings are only schematic diagrams of the present invention and are not necessarily drawn to scale. The same reference numerals in the drawings represent the same or similar parts, so the repeated description of them will be omitted. Some of the block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. The functional entities can be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor methods and / or microcontroller methods.

[0084] It should be understood that although terms such as "first", "second", etc. may be used herein to describe various units, these units should not be limited by these terms. These terms are only used to distinguish one unit from another. For example, without departing from the scope of the exemplary embodiments, the first unit may be referred to as the second unit, and similarly, the second unit may be referred to as the first unit. The term "and / or" used herein includes any and all combinations of one or more of the listed associated items.

[0085] In an embodiment of the present invention, referring to Figure 1 as shown, it is a schematic flowchart of the steps of a three-dimensional simulation design method for a ball valve according to the present invention. In this example, the three-dimensional simulation design method for the ball valve includes the following steps:

[0086] Step S1: Based on the ball valve design specifications, construct a reference geometry to obtain a preliminary geometric model; perform geometric parameterization on the preliminary geometric model to obtain an initial geometric configuration;

[0087] In an embodiment of the present invention, determine the design parameters of the ball valve (such as pressure rating, diameter, material) according to standards such as API 6D and ASME B16.34, establish a design variable table in Excel, and record in detail the name, symbol, unit, initial value, range, and constraints of each geometric parameter. Using CAD software, through commands such as extrusion and rotation, construct basic geometric shapes such as the valve body, ball, and seat based on the initial values in the design variable table to form a preliminary geometric model. Continue to add detail features such as flanges, bolt holes, valve stem holes, and sealing grooves, and parameterize the dimensions and position parameters of these features. In the CAD environment, use a parameter manager or formula editor to ensure that the dimensions and positions of all geometric features are directly or indirectly controlled by the parameters in the design variable table, and establish constraint relationships between the parameters. Finally, verify the model by modifying the parameter values in the design variable table, confirm that the model is correctly updated when the parameters change, and export it in STEP format as the "initial geometric configuration".

[0088] Step S2: Import the initial geometric configuration into a finite element analysis platform, assign material properties to obtain a finite element mesh model; perform a working stress analysis of the ball valve on the finite element mesh model to obtain a stress-strain field;

[0089] In the embodiment of the present invention, the STEP file (initial geometric configuration) obtained in the previous step is imported into the finite element analysis software to check the integrity of the geometric model and repair minor defects. In the material library of the software, corresponding material properties (such as ASTM A350 LF2, ASTM A182 F316) are assigned to components such as the valve body, sphere, valve seat, and valve stem, and parameters such as the elastic modulus, Poisson's ratio, and density of the materials are confirmed to be consistent with the specifications. The tetrahedral mesh generation method is selected, the global mesh size is set, and local mesh refinement is performed around the contact area between the valve seat and the sphere, around the valve stem hole, and around the flange bolt holes to generate a high-quality finite element mesh. A fixed constraint is applied to the surface of the flange bolt holes, and the maximum working pressure (such as 25 MPa) is applied to the inner surface of the valve. The contact types between the valve body, sphere, valve seat, and valve stem are defined as frictional contact or bonded contact. Finally, a linear static solver is selected for solution, the maximum equivalent stress (von Mises stress) and the maximum displacement are viewed and recorded, and a "stress-strain field" file containing the stress, strain, and displacement data of each node is exported.

[0090] Step S3: Perform mesh generation for the fluid domain of the model according to the initial geometric configuration and the stress-strain field to obtain the fluid domain mesh; set the valve opening change for the fluid domain mesh to obtain a CFD calculation model; perform transient simulation of the internal flow field of the ball valve at different openings for the CFD calculation model to obtain hydrodynamic parameters.

[0091] In the embodiment of the present invention, in the CAD or CFD preprocessing environment, the fluid domain geometric model is extracted from the initial geometric configuration through Boolean operations (subtracting the sphere, valve stem, and valve seat) and exported in STL format. The fluid domain geometric model and the stress-strain field data file obtained in step S2 are imported. The data mapping function is used to interpolate the nodal displacements to the fluid domain boundary, and the boundary is deformed according to the displacements to obtain a more realistic deformed fluid domain. Mesh generation is performed on the deformed fluid domain. The polyhedral mesh is selected, and a prism layer mesh is generated near the wall surface, and local refinement is performed in key areas. The curve of the valve opening change over time (such as linear change) is defined. The area containing the sphere and the valve stem is defined as the rigid body rotation area, and the rest is the deformed area. The axis and angle change of the rigid body rotation, as well as the mesh update method (such as spring smoothing) of the deformed area, are set. In the CFD solver, the fluid properties (such as water), inlet pressure, outlet pressure, wall conditions, and turbulence model (such as k-ω SST) are set to perform transient flow field simulation, calculate the flow field at each time step, update the dynamic mesh, and extract data such as the flow coefficient, pressure drop, and turbulent kinetic energy to form "hydrodynamic parameters".

[0092] Step S4: Perform transient thermal-fluid-solid coupling solution on the CFD calculation model and the finite element mesh model to obtain the transient temperature field and heat flux field; calculate the thermal stress based on the transient temperature field, heat flux field, and stress-strain field to obtain the total stress field; perform extreme thermomechanical performance evaluation based on the transient temperature field, heat flux field, and total stress field to obtain the thermomechanical performance index;

[0093] In the embodiment of the present invention, in the CFD solver, add thermal boundary conditions to the previous CFD calculation model, such as setting the fluid inlet temperature (e.g., 150 °C), ambient temperature (e.g., 25 °C), and convective heat transfer coefficient on the outer surface of the valve. Use a simulation platform that supports thermal-fluid-solid coupling (or connect CFD and FEA software), and set "bidirectional thermal coupling" boundary conditions at the interface between the fluid domain and the solid domain. Set the computational domain division and time step adaptive strategy. Set the initial temperature of the fluid domain and the solid domain, the initial velocity and pressure of the fluid domain, and the initial stress of the solid domain. In each time step, first perform fluid domain heat flux coupling calculation to obtain the fluid temperature velocity field; then calculate the interface heat exchange data; then perform solid domain temperature stress field calculation; finally, perform coupling convergence evaluation and iteration until convergence. Save the data such as the temperature field, heat flux field, and stress field at each time step to obtain the "transient temperature field and heat flux field" and the "total stress field". Based on these data, perform key hot spot area identification, thermal performance parameter calculation, thermal stress and fatigue evaluation, transient temperature response analysis, and analysis of the impact of thermal deformation on sealing performance, and finally integrate to obtain the "thermomechanical performance index".

[0094] Step S5: Perform multi-objective robust optimization based on the thermomechanical performance index, fluid dynamics parameters, and stress-strain field to obtain the optimized design scheme of the ball valve;

[0095] In the embodiment of the present invention, based on the previous analysis results, determine the optimization objectives (such as minimizing pressure drop, minimizing maximum stress, maximizing fatigue life) and constraint conditions (such as geometric dimension range, maximum stress, minimum wall thickness). Select a multi-objective optimization algorithm such as NSGA-II and set the algorithm parameters (such as population size, number of iterations, crossover probability, mutation probability). Construct a surrogate model such as a radial basis function (RBF) network, generate sample points through Latin hypercube sampling, and run CFD and FEA simulations to obtain performance indicators for training the surrogate model. Integrate the surrogate model with the optimization algorithm for iterative optimization. Every certain number of iterations, verify and update the surrogate model with CFD and FEA simulations. After optimization, obtain a set of Pareto optimal solutions, select one or more solutions according to the design requirements, and perform simulation verification again. Finally, determine the "optimized design scheme of the ball valve" including the optimized design variables and performance indicators.

[0096] Preferably, step S1 includes the following steps:

[0097] Step S11: Obtain the design specifications of the ball valve and define the design variables to obtain a design variable table;

[0098] Step S12: Construct the baseline geometry according to the design variable table to obtain a preliminary geometric model;

[0099] Step S13: Add detailed features to the preliminary geometric model to obtain a complete geometric model;

[0100] Step S14: Establish parameter associations for the complete geometric model and the design variable table to obtain a parametric geometric model;

[0101] Step S15: Verify and export the model of the parametric geometric model to obtain an initial geometric configuration.

[0102] In the embodiment of the present invention, according to the API 6D (Pipeline Valve Specification) and ASME B16.34 (Flanged, Threaded and Welded End Valves) standards, the design pressure rating of the target ball valve is determined to be Class 1500, the nominal diameter is DN100 (4 inches), the valve body material is ASTM A350 LF2 low-carbon steel, and the sphere and seat materials are ASTM A182 F316 stainless steel. Based on these specifications, key geometric parameters are extracted as design variables. Use Microsoft Excel to establish a design variable table. The columns in the table include: variable name (such as D_outer, D_inner, D_sphere, etc., consistent with the previous text), variable symbol, unit (uniformly in millimeters mm), initial value (determined according to experience or preliminary calculation), minimum value (set the lower limit according to material strength and sealing requirements), maximum value (set the upper limit according to space limitations and connector dimensions), and remarks (explain the source and constraint conditions of the variable). For example, the initial value of D_outer is set to 250 mm, the minimum value is 230 mm, and the maximum value is 270 mm.

[0103] Utilize the three-dimensional CAD modeling environment to create the basic shape of the ball valve by executing a series of geometric construction commands. First, create two concentric circle sketches in the XY plane, and the diameters of the circles are respectively linked to the D_outer and D_inner parameters in the design variable table. Then, use the "extrusion" command to extrude these two circles along the positive Z-axis direction, and the extrusion length is set to L_body (also defined in the design variable table) to form the basic cylinder of the valve body. Next, create a sphere sketch in the YZ plane, and the circle diameter is linked to the D_sphere parameter. Use the "revolution" command to rotate 360 degrees around the Y-axis to generate the sphere. Finally, create seat reference planes on both sides of the sphere (through sketches and extrusion / revolution commands, the dimensions and angles are controlled by D_seat and A_seat). The model obtained at this time only contains the basic outlines of the valve body, sphere, and seat, without any detailed features.

[0104] Based on the preliminary geometric model, continue to use CAD modeling commands to add the detailed structure of the valve. First, create flanges at both ends of the valve body by sketching the flange contour (the outer diameter and thickness are linked to D_flange and T_flange), and then perform a stretch. Then create bolt holes on the flanges, and evenly distribute multiple hole features along the circumference through the "array" command. The number and distribution angle of the holes are controlled by the newly defined parameters N_holes and A_holes. Next, create a valve stem hole inside the valve body, and the diameter is linked to D_stem. Finally, create a sealing groove in the contact area between the valve seat and the sphere by sketching the sealing groove contour on the valve seat and using the "cut" command to remove the material. The dimensions and positions of all these features are controlled by parameters as much as possible.

[0105] In the CAD environment, open the parameter manager or formula editor. Check one by one the dimensions and positioning parameters of each feature in the complete geometric model. Ensure that each dimension is directly or indirectly linked to the parameters in the design variable table. For example, the wall thickness of the valve body is related to D_outer and D_inner through the formula T_wall=(D_outer - D_inner) / 2. For dimensions that cannot be directly represented by existing parameters, create new parameters and add them to the design variable table. At the same time, add geometric constraints to ensure the rationality of the design. For example, constrain the center line of the valve stem to coincide with the center of the sphere, and constrain the valve seat to be tangent to the inner surface of the valve body. In this way, all features of the geometric model are placed under the control of parameters.

[0106] In the parameter manager of the CAD environment, modify the parameter values in the design variable table. First, increase D_outer by 10 mm, observe whether the outer diameter of the valve body increases correctly, and at the same time check whether the inner diameter and wall thickness of the valve body are automatically updated according to the associated formula. Then, decrease D_sphere by 5 mm, observe whether the sphere shrinks correctly, and check whether a reasonable gap is maintained between the sphere and the valve seat. Repeat this process to test all key parameters, including the limit values of the parameters. Confirm that the model can be correctly updated when the parameters change and no geometric errors or conflicts occur. Finally, export the model as a STEP format file, and this STEP file is the "initial geometric configuration" and serves as the input for subsequent simulation analysis.

[0107] As an example of the present invention, refer to Figure 2 As shown, in this example, step S2 includes the following steps:

[0108] Step S21: Import the initial geometric configuration into the finite element analysis software to obtain the imported geometric model;

[0109] In the embodiment of the present invention, the finite element analysis environment is started, and a new static structural analysis project is created. Using the "import" function, the STEP file (initial geometric configuration) generated in step S15 is selected as the input. In the import options, the unit system is specified as millimeters (mm), which is consistent with the CAD model. After the import is completed, the three-dimensional geometric model of the ball valve is displayed in the graphics window. The geometric inspection tool is used to check whether there are defects such as coincident surfaces, gaps, and sharp corners in the model. For the detected small gaps (less than 0.01 mm), the automatic repair function is used for repair. For larger defects, return to the CAD environment for correction and then re-import. Finally, the geometric model displayed in the graphics window is exactly the same as the CAD model and there are no geometric errors.

[0110] Step S22: Define the material properties of the imported geometric model to obtain a material property assignment model;

[0111] In the embodiment of the present invention, in the finite element analysis environment, the material library is opened. According to the material information determined in step S11, the material properties are assigned to each component of the ball valve. First, ASTM A350 LF2 low-carbon steel is selected from the material library and assigned to the valve body. Then, ASTM A182 F316 stainless steel is selected and assigned to the ball and the seat. The valve stem material is selected as ASTM A182 F316. For each material, confirm that its parameters such as elastic modulus, Poisson's ratio, and density are consistent with the material specifications. If the material data is missing in the material library, these parameters are manually input. For example, the elastic modulus of A350 LF2 is input as 205 GPa, the Poisson's ratio is input as 0.29, and the density is input as 7850 kg / m 3 . After the assignment is completed, each component in the model has clear material properties.

[0112] Step S23: Perform mesh division on the material property assignment model to obtain a finite element mesh model;

[0113] In the embodiment of the present invention, the tetrahedral mesh division method is selected. The global mesh size is set to 10 mm. In order to more accurately capture the stress concentration areas, local mesh refinement is performed on the contact area between the seat and the ball, around the valve stem hole, and around the flange bolt holes. Using the "size control" function, the mesh size is set to 2 mm in these areas. The mesh division program is started. After the division is completed, the mesh quality inspection tool is used to check the aspect ratio, Jacobian determinant, and skewness of the mesh. It is required that the aspect ratio is less than 10, the Jacobian determinant is greater than 0.3, and the skewness is less than 0.9. For the elements that do not meet the quality requirements, the mesh optimization tool is used for local adjustment, or the mesh is further refined until all elements meet the quality requirements. The finally generated mesh contains approximately 500,000 tetrahedral elements.

[0114] Step S24: Apply boundary conditions to the finite element mesh model to obtain a loaded constraint model;

[0115] In the embodiment of the present invention, fixed constraints are applied to the surfaces of the flange bolt holes at both ends of the valve body to simulate the fixing effect of bolt connection. Then, a uniform pressure load is applied to the inner surface of the valve (including the inner surfaces of the valve body, sphere and seat), and the pressure value is set to 25 MPa to simulate the maximum working pressure of a Class 1500 ball valve. The contact types between the valve body and the sphere, the valve body and the seat, and the sphere and the seat are defined as friction contacts, with the static friction coefficient set to 0.15 and the dynamic friction coefficient set to 0.1. The valve stem and the valve body are defined as a bonded contact. All these boundary conditions are completed by setting and parameter input in the corresponding interface of the finite element analysis environment.

[0116] Step S25: Solve and post-process the loaded constraint model to obtain a stress-strain field;

[0117] In the embodiment of the present invention, a linear static solver is selected for solving. Start the solution calculation. After the calculation is completed, view the stress contour map. Find the position of the maximum equivalent stress (von Mises stress) and record its value. For example, the maximum equivalent stress appears in the contact area between the seat and the sphere, with a value of 350 MPa. Then, view the displacement contour map and record the maximum displacement value. For example, the maximum displacement appears on the sphere, with a value of 0.1 mm. Finally, export a text file or binary file containing the stress, strain, and displacement data of each node. This file is the "stress-strain field" and serves as the input for subsequent analysis. Evaluate the results to ensure that the maximum stress is less than the yield strength of the material, ensuring the rationality of the results.

[0118] Preferably, the model fluid domain mesh generation described in step S3 includes:

[0119] Extract the fluid domain from the initial geometric configuration to obtain a fluid domain geometric model;

[0120] Map the node displacement data in the stress-strain field to the boundary of the fluid domain geometric model, and update the fluid domain considering deformation to obtain a deformed fluid domain;

[0121] Perform fluid domain mesh generation on the deformed fluid domain to obtain a fluid domain mesh.

[0122] In the embodiment of the present invention, in the CAD environment or the CFD pre-processing environment, open the initial geometric configuration (STEP file) generated in step S15. Use the Boolean operation tool to subtract the solid parts of the sphere, valve stem, and valve seat from the inner cavity of the valve body. The specific operation is as follows: Select the inner surface of the valve body as the "target body", select the sphere, valve stem, and valve seat as the "tool bodies", and perform the "subtract" operation. After the operation is completed, a solid representing the fluid flow space is obtained, which is the geometric model of the fluid domain. Check the boundaries of the fluid domain to ensure that they fit perfectly with the inner surfaces of the valve body, sphere, and valve seat, without gaps or overlaps. Export the geometric model of the fluid domain as an STL format file.

[0123] In the CFD pre-processing environment, import the geometric model of the fluid domain (STL file) generated in the previous step and the stress-strain field data file generated in step S25. Use the data mapping function to interpolate the nodal displacement data in the stress-strain field to the boundary nodes of the geometric model of the fluid domain. The specific operation is as follows: Select the stress-strain field data file as the "source data", select the boundary nodes of the geometric model of the fluid domain as the "target positions", and select the inverse distance weighted interpolation method. After the interpolation is completed, each boundary node obtains the corresponding displacement vector. Then, use the deformed mesh function to deform the geometric model of the fluid domain according to the displacement vectors of the boundary nodes. During the deformation process, keep the mesh topology unchanged and only change the node positions. After the deformation is completed, the deformed fluid domain is obtained, and its shape is closer to the flow channel shape of the valve under the actual working pressure.

[0124] In the CFD pre-processing environment, perform mesh division on the deformed fluid domain generated in the previous step. Select the polyhedral mesh division method. Set the global mesh size to 5 mm. In order to accurately capture the flow in the boundary layer, generate a prism layer mesh in the area close to the wall surface. Set the number of prism layers to 5 layers, the height of the first layer to 0.1 mm, and the growth rate to 1.2. In the narrow area between the valve seat and the sphere, and in the area where the flow separates, use the local mesh refinement function to set the mesh size to 1 mm. Start the mesh division program. After the division is completed, use the mesh quality inspection tool to check the aspect ratio, skewness, and orthogonality quality of the mesh. It is required that the aspect ratio is less than 20, the skewness is less than 0.95, and the orthogonality quality is greater than 0.1. For the elements that do not meet the quality requirements, use the mesh optimization tool for local adjustment, or further refine the mesh until all elements meet the quality requirements. The finally generated mesh contains approximately 800,000 elements, mainly polyhedral elements and prism layer elements.

[0125] Preferably, the valve opening change setting in step S3 includes:

[0126] Obtain the valve type and control parameters, and define the valve opening change curve to obtain the valve opening change data;

[0127] Define the dynamic mesh region according to the valve opening change data and the fluid domain mesh, and define the movement mode of the ball valve opening to obtain the dynamic mesh movement setting;

[0128] Update the dynamic mesh parameters according to the dynamic mesh movement setting and the fluid domain mesh to obtain the CFD calculation model.

[0129] In the embodiment of the present invention, it is determined that the simulated ball valve is a rotary ball valve, and its opening is defined by the rotation angle of the sphere around the valve stem axis. The total simulation time is set to 1 second, and the process of the valve from fully closed (0 degrees) to fully open (90 degrees) is simulated. Use a linear function to define the change of the valve opening with time: opening (degrees) = 90 * t (seconds). This means that the valve opens uniformly within 1 second. Discretize this function into a series of time points and corresponding opening values. For example, generate a time series containing 101 data points, with time ranging from 0 second to 1 second and a step size of 0.01 second, and each time point corresponds to an opening value (from 0 degrees to 90 degrees). Save these data as a CSV format file, which is the valve opening change data.

[0130] In the CFD pre-processing environment, import the fluid domain mesh generated in the previous step (model fluid domain mesh generation). Use the "dynamic mesh" function to define the region containing the sphere and the valve stem as the rigid body motion region. The remaining fluid domain is defined as the deformed region. For the rigid body motion region, specify its motion mode as "rigid body rotation". The rotation axis is set as the vector passing through the center line of the valve stem. The change of the rotation angle with time is read from the valve opening change data (CSV file) generated in the previous step. This means that the sphere will rotate according to the pre-defined opening curve. For the deformed region, select the "spring smoothing" method to update the mesh. Set the spring constant to 0.5. These settings define the motion mode and parameters of the dynamic mesh, which is the dynamic mesh movement setting.

[0131] Based on the dynamic mesh movement setting in the previous step and the fluid domain mesh, initialize and update the dynamic mesh parameters. In the CFD solver, enable the "dynamic mesh" option. Specify the time step as 0.01 second, which is consistent with the time step of the valve opening change data. At the beginning of each time step, the solver updates the mesh position of the rigid body motion region according to the dynamic mesh movement setting (the rotation angle of the sphere). Then, according to the spring smoothing method, adjust the mesh node positions of the deformed region to adapt to the displacement of the rigid body motion region. This process is repeated at each time step, so as to realize the dynamic opening of the ball valve during the simulation. The updated fluid domain mesh and boundary conditions containing the dynamic mesh parameters constitute the complete CFD calculation model.

[0132] Preferably, the transient simulation of the internal flow field of the ball valve at different openings in step S3 includes:

[0133] Initialize the flow field of the CFD calculation model to obtain the initial flow field data;

[0134] Calculate the sphere rotation matrix within each time step based on the initial flow field data, and perform fluid domain partitioning to obtain the dynamic grid data;

[0135] Perform transient flow field calculation based on the dynamic grid data and the initial flow field data to obtain the transient flow field data;

[0136] Calculate the turbulence parameters based on the transient flow field data and the dynamic grid data to obtain the turbulence characteristic data;

[0137] Perform valve flow performance analysis based on the turbulence characteristic data and the transient flow field data to obtain the valve performance indicators;

[0138] Perform post - processing of the flow field data based on the valve performance indicators, the turbulence characteristic data, and the transient flow field data to obtain the hydrodynamic parameters.

[0139] In the embodiment of the present invention, in the CFD solver, initialize the flow field of the CFD calculation model obtained in the previous step (valve opening change setting). Set the fluid as water, with a density of 998.2 kg / m 3 , and a dynamic viscosity of 0.001003 Pa·s. Set the inlet boundary condition as a pressure inlet, with a gauge pressure of 25 MPa, which is consistent with the pressure load in step S24. Set the outlet boundary condition as a pressure outlet, with a gauge pressure of 0 MPa. Set all wall surfaces as non - slip boundary conditions. Set the initial flow field velocity as 0 m / s, that is, assume the fluid is in a static state before the valve opens. Select the k - ω SST turbulence model. After initialization, obtain a distribution of parameters such as the initial pressure, velocity, turbulent kinetic energy (k), and turbulent dissipation rate (ω) of each grid cell within the entire fluid domain, which is the initial flow field data.

[0140] At the beginning of each time step, calculate the angle that the sphere needs to rotate at the current moment according to the predefined valve opening change data (the output of "valve opening change setting" in step S3). Use the rotation angle and the valve stem axis vector to construct a 4x4 rotation matrix. Apply this rotation matrix to the coordinates of all grid nodes in the rigid body motion region (including the sphere and the valve stem) to realize the rotation of the sphere. Then, re - divide the fluid domain according to the updated grid positions. For the deformed region, use the spring smoothing algorithm or other grid deformation methods to adjust the grid node positions to adapt to the displacement of the rigid body motion region and maintain the grid quality. The updated grid node coordinates and element connection relationships are the dynamic grid data.

[0141] Based on the dynamic grid data and the initial flow field data obtained in the previous step (or the calculation results of the previous time step), the Navier-Stokes equations are solved using the finite volume method. The SIMPLEC algorithm is adopted for pressure-velocity coupling. The convective term is discretized using the second-order upwind scheme, the diffusion term is discretized using the central difference scheme, and the time term is discretized using the second-order implicit scheme. Within each time step, the discretized equations are iteratively solved until the residuals converge to below 1e-5 or the maximum number of iterations (e.g., 20 times) is reached. After the solution is completed, the distributions of parameters such as pressure and velocity of each grid cell within the entire fluid domain at the current time step are obtained, which are the transient flow field data.

[0142] Based on the transient flow field data (velocity field) and the dynamic grid data obtained in the previous step, the source terms of the turbulence model are calculated. For the k-ω SST model, the turbulent kinetic energy generation term and the dissipation term are calculated according to the velocity gradient. The turbulent kinetic energy (k) and the turbulent dissipation rate (ω) of each grid cell are updated. These updated turbulence parameters, including the turbulent kinetic energy, the turbulent dissipation rate, the turbulent viscosity, etc., are the turbulence characteristic data. These data reflect the turbulence intensity and distribution of the flow field at the current moment and the current opening degree.

[0143] Based on the transient flow field data and the turbulence characteristic data, the flow coefficient (Cv) and the pressure drop (ΔP) of the valve are calculated. By integrating the mass flow rates at the inlet and outlet, the instantaneous flow rate through the valve is obtained. According to the flow rate and the pressure difference between the inlet and outlet, the instantaneous flow coefficient is calculated. By integrating the pressure on the inner surface of the valve, the total pressure drop of the valve is obtained. At the same time, parameters such as the vorticity and the turbulent kinetic energy inside the valve can also be calculated to analyze the detailed characteristics of the flow field. These calculated flow coefficients, pressure drops, vorticities, etc., are the valve performance indicators.

[0144] The valve performance indicators (flow coefficient, pressure drop, etc.), the turbulence characteristic data (turbulent kinetic energy, turbulent dissipation rate, etc.), and the transient flow field data (pressure, velocity, etc.) calculated at each time step are saved to a file. Curves of the flow coefficient varying with the opening degree and curves of the pressure drop varying with the opening degree are generated. Using CFD post-processing software, velocity vector diagrams, pressure contour diagrams, streamline diagrams, and turbulent kinetic energy distribution diagrams at different opening degrees are generated. These data and charts, as well as other possible analysis results (such as the vortex intensity, the size of the separation zone, etc.), constitute the complete hydrodynamic parameters for evaluating the flow performance of the valve at different opening degrees.

[0145] Preferably, the transient thermal-fluid-solid coupling solution described in step S4 includes:

[0146] Define the thermal boundary conditions for the CFD calculation model to obtain the thermally loaded CFD model;

[0147] Perform thermal coupling settings at the fluid-structure interface for the thermally loaded CFD model and the finite element mesh model to obtain a coupled calculation model;

[0148] Divide the calculation domain of the coupled calculation model and perform time step adaptive processing to obtain a set of coupled calculation parameters;

[0149] Set the initial conditions of multiple physical fields according to the set of coupled calculation parameters to obtain the initial state of multiple physical fields;

[0150] Perform fluid domain thermal-fluid coupling calculation according to the initial state of multiple physical fields to obtain the fluid temperature velocity field;

[0151] Perform interface heat exchange calculation according to the fluid temperature velocity field to obtain interface heat exchange data;

[0152] Perform solid domain temperature stress field calculation according to the interface heat exchange data to obtain the solid temperature stress field;

[0153] Perform coupled convergence evaluation and iterative control according to the fluid temperature velocity field, the solid temperature stress field, and the interface heat exchange data to obtain the coupled iteration state;

[0154] Perform time advancement and result integration according to the fluid temperature velocity field, the solid temperature stress field, and the coupled iteration state to obtain the transient temperature field and the heat flow field.

[0155] In the embodiment of the present invention, in the CFD solver, open the CFD calculation model obtained in the previous step (transient simulation of the internal flow field of the ball valve at different opening degrees). Assume that the fluid inlet temperature is 150 °C and remains constant. Modify the inlet boundary condition to "temperature inlet" and input the temperature value of 150 °C. Assume that there is natural convection heat transfer between the outer surface of the valve and the ambient air, and the ambient temperature is 25 °C. Set the "convection heat transfer" boundary condition on the outer surface of the valve (including the valve body, flange, etc.), input the ambient temperature of 25 °C, and the convection heat transfer coefficient is set to 10 W / (m 2 ·K) (determined according to empirical values or by looking up tables). Assume that the initial temperature inside the valve is 25 °C. The setting of these thermal boundary conditions introduces thermal effects into the CFD model to obtain the thermally loaded CFD model.

[0156] Use a simulation platform that supports thermal-fluid-solid coupling (or connect CFD and FEA software through an interface). Import the thermal loading CFD model and the finite element mesh model obtained in step S23. Set "thermal coupling" boundary conditions at the interface between the fluid domain and the solid domain (i.e., the inner surface of the valve, including the inner surfaces of the valve body, sphere, and seat). Specify the thermal coupling method as "bidirectional coupling", which allows heat to transfer from the fluid to the solid and also from the solid to the fluid. Ensure good matching of the fluid domain mesh and the solid domain mesh at the interface to guarantee the accuracy of heat transfer. This setting thermally connects the fluid domain and the solid domain to form a complete coupled calculation model.

[0157] Divide the coupled calculation model into two computational domains: the fluid domain and the solid domain. For the fluid domain, use the same time step (0.01 s) as in the previous transient flow field simulation. For the solid domain, since the heat conduction process is relatively slow, the initial time step can be set larger, for example, 0.1 s. Enable the time step adaption function. Set the minimum time step to 0.001 s and the maximum time step to 1 s. The basis for time step adaption is the temperature change rate in the fluid domain and the solid domain. If the temperature change rate exceeds a preset threshold (e.g., 1 °C per step), the time step is decreased; if the temperature change rate is below the threshold, the time step is increased. These time step settings and adaption strategies, along with other solution parameters (such as convergence criteria), constitute the coupled calculation parameter set.

[0158] Based on the coupled calculation parameter set obtained in the previous step, set the initial conditions for the fluid domain and the solid domain. The initial velocity and pressure fields in the fluid domain use the results of the previous transient flow field simulation (or are set to a stationary state with a pressure of 25 MPa). The initial temperatures of both the fluid domain and the solid domain are set to 25 °C (consistent with the ambient temperature). The initial stress state of the solid domain uses the stress-strain field data obtained in step S25. The setting of these initial conditions defines the state of the entire coupled system at the start of the simulation, i.e., the multi-physical field initial state.

[0159] In each time step, first solve the Navier-Stokes equations and the energy equation in the fluid domain. Use the same numerical methods (finite volume method, SIMPLEC algorithm, etc.) as in the previous transient flow field simulation. In addition to calculating the velocity and pressure, also calculate the temperature of the fluid. Consider the viscous dissipation heat generated by fluid flow. Since the valve is dynamically opened, the dynamic mesh technology still needs to be used to handle the rotation of the sphere. After the solution is completed, obtain the temperature, velocity, and pressure distributions in the fluid domain at the current time step, i.e., the fluid temperature velocity field.

[0160] Based on the fluid temperature and velocity field obtained in the previous step, calculate the heat flux density on the interface between the fluid domain and the solid domain. Calculate the heat flux density of each interface element according to the difference between the fluid temperature and the wall temperature (the surface temperature of the solid domain), and the convective heat transfer coefficient on the fluid side (calculated according to the turbulence model). Integrate the heat flux density of all interface elements to obtain the total heat exchange amount. These heat flux density and total heat exchange amount data are the interface heat exchange data.

[0161] Take the interface heat exchange data (heat flux density) obtained in the previous step as the boundary condition and apply it to the inner surface of the solid domain (i.e., the fluid-solid interface). Solve the heat conduction equation in the solid domain to obtain the temperature distribution of the solid domain. Then, based on the temperature distribution and the thermal expansion coefficient of the material, calculate the thermal stress caused by the temperature change. Superimpose the thermal stress with the original mechanical stress (the result of step S25) to obtain the total stress. After the solution is completed, obtain the temperature and stress distribution of the solid domain at the current time step, that is, the solid temperature stress field.

[0162] Within each time step, compare the fluid temperature, solid temperature, and interface heat flux density obtained in this iteration with the results of the previous iteration. If the difference between them is less than the preset convergence criterion (for example, the temperature difference is less than 0.1 °C and the heat flux density difference is less than 1%), it is considered that the coupled calculation converges. If it does not converge, update the boundary condition using the results of this iteration and perform the next iteration until convergence. Record the residual and the number of iterations for each iteration. These convergence information and the number of iterations are the coupled iteration status.

[0163] When the coupled calculation converges at the current time step, advance the time to the next time step. Repeat the above fluid domain calculation, interface heat exchange calculation, solid domain calculation, and coupled iteration process until the total simulation time is reached. Save the fluid temperature field, solid temperature field, and interface heat flux density data calculated at each time step to a file. These data, as well as other possible required analysis results (such as thermal stress, thermal deformation, etc.), constitute the complete transient temperature field and heat flux field for evaluating the thermodynamic performance of the valve under extreme temperature conditions.

[0164] Preferably, the evaluation of the extreme temperature thermodynamic performance in step S4 includes:

[0165] Conduct thermodynamic performance evaluation based on the transient temperature field, heat flux field, and total stress field to obtain thermodynamic performance indicators;

[0166] Identify and extract key hot spot regions based on the transient temperature field, heat flux field, and total stress field to obtain key thermodynamic region data;

[0167] Conduct quantitative calculation of thermal performance parameters based on the key thermodynamic region data to obtain a set of thermal performance parameters;

[0168] Based on the total stress field, transient temperature field, heat flux field, and data of key thermodynamic regions, thermal stress intensity and thermal fatigue are evaluated to obtain thermal fatigue risk assessment data;

[0169] Based on the transient temperature field, heat flux field, and data of key thermodynamic regions, transient temperature response curve analysis is carried out to obtain a set of temperature response characteristic curves;

[0170] Based on the transient temperature field, heat flux field, total stress field, and thermal fatigue risk assessment data, an analysis of the influence of thermal deformation on sealing performance is obtained to obtain thermal sealing performance assessment data;

[0171] Based on the set of thermal performance parameters, thermal fatigue risk assessment data, temperature response characteristic curve set, and thermal sealing performance assessment data, comprehensive performance indicators are constructed to obtain thermodynamic performance indicators.

[0172] In the embodiments of the present invention, based on the transient temperature field and heat flux field (output from transient thermal-fluid-solid coupling solution) and the total stress field (including thermal stress and mechanical stress), a series of analyses and calculations are carried out to evaluate the performance of the valve under extreme temperature conditions. These analyses and calculations include key hot spot region identification, thermal performance parameter calculation, thermal stress and thermal fatigue assessment, transient temperature response analysis, analysis of the influence of thermal deformation on sealing performance, etc. The data obtained through these analyses, after integration and processing, form a set of indicators that can quantitatively characterize the thermodynamic performance of the valve, namely, thermodynamic performance indicators. These indicators include the maximum temperature, maximum thermal stress, maximum thermal deformation, heat loss, time to reach steady state, etc.

[0173] In the CFD and FEA post-processing environment, view the transient temperature field contour plot. Identify the regions with the highest temperature, such as the region where the valve seat contacts the sphere and the part of the valve body near the hot fluid inlet. View the heat flux density contour plot and identify the regions with the highest heat flux density, such as the region where the inner surface of the valve body contacts the hot fluid. View the total stress field contour plot and identify the regions with the maximum total stress (including thermal stress and mechanical stress), such as the region where the valve seat contacts the sphere and the stress concentration regions on the valve body. Define these regions with high temperature, high heat flux density, and high stress as key hot spot regions. Extract the node coordinates, temperature, heat flux density, and stress data of these regions, which are the data of key thermodynamic regions.

[0174] Based on the key thermodynamic region data obtained in the previous step, calculate a series of parameters characterizing the thermal performance of the valve. Calculate the average temperature, the maximum temperature, and the minimum temperature in the key hot spot regions. Calculate the average heat flux density and the maximum heat flux density in the key hot spot regions. Calculate the maximum equivalent stress (von Mises stress) and the maximum principal stress in the key hot spot regions. Calculate the overall heat loss through the valve (by integrating the heat flux density on the outer surface of the valve). These calculated parameters, along with other parameters that may be required (such as temperature gradient, thermal strain, etc.), constitute the set of thermal performance parameters.

[0175] Based on the total stress field data, extract the maximum thermal stress in the key hot spot regions. Compare the maximum thermal stress with the yield strength of the material at the corresponding temperature to evaluate whether the thermal stress exceeds the strength limit of the material. Use the Miner linear cumulative damage rule or other fatigue analysis methods, combined with the transient temperature field and total stress field data, to evaluate the fatigue life of the valve under cyclic temperature loads. For example, calculate the fatigue damage factor according to the amplitude and frequency of the temperature cycle, and the S-N curve (fatigue strength curve) of the material. These evaluation results, including the maximum thermal stress, safety factor, fatigue life, fatigue damage factor, etc., are the thermal fatigue risk assessment data.

[0176] Extract the curves of the temperature change with time in the key hot spot regions from the transient temperature field data. For example, plot the curve of the maximum temperature of the valve seat changing with time, and the curve of the maximum temperature of the valve body changing with time. Analyze the characteristics of these curves, such as the heating rate, the time to reach steady state, the amplitude and frequency of temperature fluctuations, etc. These curves and analysis results are the set of temperature response characteristic curves, which reflect the temperature response characteristics of the valve under transient thermal loads.

[0177] Calculate the thermal deformation of each component of the valve caused by temperature changes from the transient temperature field data. Pay particular attention to the thermal deformation of the valve seat and the sphere, as they directly affect the sealing performance. Calculate the relative displacement between the valve seat and the sphere, and evaluate whether the thermal deformation causes an increase or decrease in the sealing gap. Combine the total stress field data to analyze whether the thermal stress causes plastic deformation of the valve seat or the sphere, thus affecting the sealing performance. If the leakage rate simulation is carried out (which usually requires a more complex model), the change in the leakage rate can be evaluated based on the thermal deformation and stress state. These analysis results, including the amount of thermal deformation, relative displacement, change in sealing gap, change in leakage rate (if any), etc., are the thermal sealing performance assessment data.

[0178] Integrate the thermal performance parameter set, thermal fatigue risk assessment data, temperature response characteristic curve set, and thermal sealing performance assessment data obtained in the previous steps. According to different design objectives and performance requirements, perform weighted averaging or other forms of comprehensive processing on these data to obtain a set of indicators that can comprehensively reflect the thermodynamic performance of the valve. For example, a comprehensive performance indicator can be constructed, including multiple factors such as maximum temperature, maximum thermal stress, fatigue life, thermal deformation, and sealing performance, and different weights are assigned according to the importance of each factor. The final set of indicators obtained is the thermodynamic performance indicator, which is used to guide the subsequent optimization design.

[0179] Preferably, step S5 includes the following steps:

[0180] Step S51: Define the optimization objectives and constraints according to the thermodynamic performance indicators, fluid dynamics parameters, and stress-strain field to obtain the optimization objective and constraint problem;

[0181] Step S52: Select the optimization algorithm and set the parameters according to the optimization objective and constraint problem to obtain the optimization algorithm configuration;

[0182] Step S53: Construct a surrogate model according to the optimization objective and constraint problem to obtain the surrogate model;

[0183] Step S54: Perform optimization iteration and simulation verification according to the surrogate model and the optimization algorithm configuration to obtain the optimization process data;

[0184] Step S55: Select the optimization scheme from the optimization process data to obtain the optimized design scheme of the ball valve.

[0185] In the embodiment of the present invention, based on the analysis results obtained in the previous steps, the optimization objectives and constraints are determined. The optimization objectives are set as follows: 1. Minimize the pressure drop of the valve in the fully open state (from fluid dynamics parameters); 2. Minimize the maximum equivalent stress of the valve under extreme temperature conditions (from thermodynamic performance indicators and stress-strain field); 3. Maximize the fatigue life of the valve under cyclic temperature loads (from thermodynamic performance indicators). The constraint conditions are set as follows: 1. The geometric dimensions of the valve must be within the range specified in the design variable table (step S11); 2. The maximum equivalent stress of the valve under the maximum working pressure must be less than the yield strength of the material (from the stress-strain field); 3. The minimum wall thickness of the valve must meet the requirements of the API 6D standard. Express these objectives and constraint conditions in mathematical formulas to form a clear optimization problem.

[0186] For the multi-objective optimization problem defined in the previous step, the Non-dominated Sorting Genetic Algorithm II (NSGA-II) is selected as the optimization algorithm. NSGA-II is a commonly used multi-objective optimization algorithm, especially suitable for dealing with optimization problems with multiple conflicting objectives. Set the parameters of the algorithm: the population size is set to 100, the maximum number of iterations is set to 50, the crossover probability is set to 0.9, and the mutation probability is set to 0.1. The settings of these parameters are determined based on experience and the complexity of the problem. After the settings are completed, the configuration of the optimization algorithm is obtained to guide the subsequent optimization iteration process.

[0187] Since the computational cost of directly using CFD and FEA models for optimization iteration is too high, a surrogate model is constructed to approximately simulate the performance of the ball valve. The Radial Basis Function (RBF) network is selected as the surrogate model. Using the Latin Hypercube Sampling (LHS) method, 200 sample points are generated in the design variable space. For each sample point, a complete CFD and FEA simulation (including thermal-fluid-solid coupling analysis) is run to obtain the corresponding performance indicators (pressure drop, maximum stress, fatigue life). Using these sample points and performance indicator data, the RBF network is trained. After training is completed, a surrogate model that can quickly predict the performance of the ball valve is obtained, with the design variables as the input and the performance indicators as the output.

[0188] Integrate the surrogate model constructed in the previous step with the NSGA-II algorithm. In each iteration, the NSGA-II algorithm generates a new population based on the current population (a set of design schemes). The surrogate model is used to quickly evaluate the performance indicators (pressure drop, maximum stress, fatigue life) of each design scheme in the new population. Based on these performance indicators, the NSGA-II algorithm performs sorting, selection, crossover, and mutation operations on the population to generate the next generation population. Repeat this process until the maximum number of iterations is reached. During the optimization process, every 10 iterations, select some excellent individuals in the current population (such as individuals on the Pareto front), run complete CFD and FEA simulations for verification, and use the simulation results to update the surrogate model. Record the data of the population, performance indicators, surrogate model error, etc. for each iteration, which is the optimization process data.

[0189] After the optimization iteration is completed, a set of Pareto optimal solutions (non-dominated solutions) are obtained, and these solutions represent different trade-offs among pressure drop, maximum stress, and fatigue life. According to the design requirements and priorities, one or more design schemes are selected from the Pareto optimal solutions. For example, if more attention is paid to reducing the pressure drop, the scheme with the minimum pressure drop is selected; if more attention is paid to improving the fatigue life, the scheme with the longest fatigue life is selected; if multiple objectives need to be considered, a compromise scheme is selected. For the selected design scheme, the complete CFD and FEA simulations are run again for verification to ensure that its performance meets the design requirements. The finally determined design scheme is the optimized design scheme of the ball valve, which includes the optimized design variable values and the corresponding performance indicators.

[0190] Preferably, the present invention further provides a three-dimensional simulation design system for a ball valve, which is used to execute the three-dimensional simulation design method for a ball valve as described above. The three-dimensional simulation design system for a ball valve includes:

[0191] A geometric parameterization modeling module, which is used to construct a benchmark geometry based on the ball valve design specifications to obtain a preliminary geometric model; perform geometric parameterization on the preliminary geometric model to obtain an initial geometric configuration;

[0192] A static structural analysis module, which is used to import the initial geometric configuration into a finite element analysis platform, assign material properties to obtain a finite element mesh model; perform a working stress analysis of the ball valve on the finite element mesh model to obtain a stress-strain field;

[0193] A transient flow field simulation module, which is used to perform model fluid domain mesh generation according to the initial geometric configuration and the stress-strain field to obtain a fluid domain mesh; set the valve opening change for the fluid domain mesh to obtain a CFD calculation model; perform a transient simulation of the internal flow field of the ball valve at different opening degrees on the CFD calculation model to obtain hydrodynamic parameters;

[0194] A coupled thermodynamics analysis module, which is used to perform transient thermal-fluid-solid coupling solution on the CFD calculation model and the finite element mesh model to obtain a transient temperature field and a heat flow field; calculate thermal stress according to the transient temperature field, the heat flow field, and the stress-strain field to obtain a total stress field; perform an extreme thermomechanical performance evaluation according to the transient temperature field, the heat flow field, and the total stress field to obtain thermomechanical performance indicators;

[0195] A multi-objective robust optimization module, which is used to perform multi-objective robust optimization according to the thermomechanical performance indicators, the hydrodynamic parameters, and the stress-strain field to obtain an optimized design scheme of the ball valve.

[0196] Therefore, from any perspective, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Accordingly, all changes that fall within the meaning and scope of the equivalent elements of the application documents are intended to be encompassed within the present invention.

[0197] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features invented herein.

Claims

1. A three-dimensional simulation design method for a ball valve, characterized in that: The following steps are involved: Step S1: constructing a reference geometry based on the ball valve design specification to obtain a preliminary geometry model; Perform geometric parameterization on the preliminary geometric model to obtain an initial geometric configuration; Step S2: importing the initial geometric configuration into the finite element analysis platform, assigning material properties, and obtaining a finite element mesh model; performing ball valve working stress analysis on the finite element mesh model to obtain a stress-strain field; Step S3: meshing the model fluid domain according to the initial geometric configuration and the stress-strain field to obtain a fluid domain mesh; setting the valve opening change on the fluid domain mesh to obtain a CFD calculation model; The CFD calculation model is used to perform transient simulation of the internal flow field of the ball valve at different openings to obtain the fluid dynamics parameters; Step S4: performing transient heat-fluid-solid coupling solution on the CFD calculation model and the finite element mesh model to obtain transient temperature field and thermal flow field; Thermal stress calculation is performed based on transient temperature field, heat flow field and stress-strain field to obtain the total stress field; extreme temperature thermodynamic performance evaluation is performed based on transient temperature field, heat flow field and total stress field to obtain thermodynamic performance indicators; Step S5: Perform multi-objective robust optimization according to thermodynamic performance indicators, fluid dynamics parameters and stress-strain field to obtain an optimized design solution for the ball valve.

2. The three-dimensional simulation design method for a ball valve according to claim 1, characterized in that: Step S1 includes the following steps: Step S11: obtaining the ball valve design specification, and defining the design variables to obtain a design variable table; Step S12: constructing a reference geometry according to the design variable table to obtain a preliminary geometry model; Step S13: adding detailed features to the preliminary geometric model to obtain a complete geometric model; Step S14: establishing parameter association between the complete geometric model and the design variable table to obtain a parameterized geometric model; Step S15: verify and export the parameterized geometric model to obtain an initial geometric configuration.

3. The three-dimensional simulation design method for a ball valve according to claim 1, characterized in that: Step S2 includes the following steps: Step S21: importing the initial geometric configuration into finite element analysis software to obtain an imported geometric model; Step S22: defining material properties for the imported geometric model to obtain a material property allocation model; Step S23: meshing the material property distribution model to obtain a finite element mesh model; Step S24: applying boundary conditions to the finite element mesh model to obtain a loading constraint model; Step S25: Solve and post-process the loading constraint model to obtain the stress-strain field.

4. The three-dimensional simulation design method for a ball valve according to claim 1, characterized in that: The meshing of the model fluid domain described in step S3 includes: Perform fluid domain extraction on the initial geometric configuration to obtain a fluid domain geometric model; The node displacement data in the stress-strain field is mapped to the boundary of the fluid domain geometric model, and the fluid domain is updated considering the deformation to obtain the deformed fluid domain; The fluid domain is meshed for the deformed fluid domain to obtain a fluid domain mesh.

5. The three-dimensional simulation design method for a ball valve according to claim 1, characterized in that: The valve opening change setting in step S3 includes: Obtain valve type and control parameters, define valve opening change curve, and obtain valve opening change data; The dynamic mesh area is defined according to the valve opening change data and the fluid domain mesh, and the ball valve opening movement mode is defined to obtain the dynamic mesh movement setting; The dynamic mesh parameters are updated according to the dynamic mesh motion settings and the fluid domain mesh to obtain the CFD calculation model.

6. The three-dimensional simulation design method for a ball valve according to claim 1, characterized in that: The transient simulation of the internal flow field of the ball valve at different openings described in step S3 includes: Initialize the flow field of the CFD calculation model to obtain initial flow field data; The sphere rotation matrix is ​​calculated in each time step according to the initial flow field data, and the fluid domain is partitioned to obtain dynamic grid data; Perform transient flow field calculation according to dynamic grid data and initial flow field data to obtain transient flow field data; The turbulence parameters are calculated based on the transient flow field data and the dynamic grid data to obtain the turbulence characteristic data; Analyze valve flow performance based on turbulence characteristic data and transient flow field data to obtain valve performance indicators; The flow field data are post-processed according to the valve performance index, turbulence characteristic data and transient flow field data to obtain the fluid dynamics parameters.

7. The three-dimensional simulation design method for a ball valve according to claim 1, characterized in that: The transient thermal-fluid-solid coupling solution described in step S4 includes: Define the thermal boundary conditions for the CFD calculation model to obtain a thermal loading CFD model; Perform fluid-solid interface thermal coupling settings on the thermal loading CFD model and the finite element mesh model to obtain a coupled calculation model; The coupled calculation model is divided into calculation domains, and the time step is adaptively processed to obtain the coupled calculation parameter set; The initial conditions of the multi-physics field are set according to the coupled calculation parameter set to obtain the initial state of the multi-physics field; Perform thermal-fluid coupling calculation in the fluid domain according to the initial state of the multi-physics field to obtain the fluid temperature and velocity field; Calculate the interface heat exchange according to the fluid temperature and velocity field to obtain the interface heat exchange data; The solid domain temperature stress field is calculated based on the interface heat exchange data to obtain the solid temperature stress field; According to the fluid temperature velocity field, solid temperature stress field and interface heat exchange data, coupled convergence evaluation and iterative control are performed to obtain the coupled iterative state; Time advancement and result integration are performed according to the fluid temperature velocity field, solid temperature stress field and coupled iterative state to obtain the transient temperature field and thermal flow field.

8. The three-dimensional simulation design method for a ball valve according to claim 1, characterized in that: The extreme temperature thermodynamic performance evaluation described in step S4 includes: Thermodynamic performance evaluation is performed based on transient temperature field, heat flow field and total stress field to obtain thermodynamic performance indicators; According to the transient temperature field, thermal flow field and total stress field, key hot spot areas are identified and extracted to obtain key thermodynamic area data; Quantitative calculation of thermal performance parameters is performed based on key thermodynamic region data to obtain a thermal performance parameter set; Thermal stress intensity and thermal fatigue assessment are performed based on the total stress field, transient temperature field, thermal flow field and key thermodynamic area data to obtain thermal fatigue risk assessment data; According to the transient temperature field, thermal flow field and key thermodynamic area data, transient temperature response curve analysis is performed to obtain a set of temperature response characteristic curves; According to the transient temperature field and thermal flow field, total stress field and thermal fatigue risk assessment data, the influence of thermal deformation on sealing performance is analyzed and the thermal sealing performance assessment data is obtained; A comprehensive performance index is constructed based on the thermal performance parameter set, thermal fatigue risk assessment data, temperature response characteristic curve set and thermal sealing performance assessment data to obtain the thermodynamic performance index.

9. The three-dimensional simulation design method for a ball valve according to claim 1, characterized in that: Step S5 includes the following steps: Step S51: defining optimization objectives and constraints according to thermodynamic performance indicators, fluid dynamics parameters and stress-strain fields to obtain optimization objectives and constraint problems; Step S52: Select an optimization algorithm and set parameters according to the optimization goal and constraint problem to obtain an optimization algorithm configuration; Step S53: constructing a proxy model according to the optimization goal and the constraint problem to obtain a proxy model; Step S54: performing optimization iteration and simulation verification according to the proxy model and optimization algorithm configuration to obtain optimization process data; Step S55: Select an optimization solution for the optimization process data to obtain an optimized design solution for the ball valve.

10. A three-dimensional simulation design system for a ball valve, characterized in that: For executing the three-dimensional simulation design method for a ball valve as claimed in claim 1, the three-dimensional simulation design system for a ball valve comprises: The geometric parameterization modeling module is used to construct the reference geometry based on the ball valve design specification to obtain a preliminary geometric model; geometric parameterization is performed on the preliminary geometric model to obtain an initial geometric configuration; The static structural analysis module is used to import the initial geometric configuration into the finite element analysis platform, assign material properties, and obtain a finite element mesh model; perform ball valve working stress analysis on the finite element mesh model to obtain the stress-strain field; The transient flow field simulation module is used to divide the model fluid domain grid according to the initial geometric configuration and stress-strain field to obtain the fluid domain grid; set the valve opening change on the fluid domain grid to obtain the CFD calculation model; perform transient simulation of the internal flow field of the ball valve at different openings on the CFD calculation model to obtain the fluid dynamics parameters; The coupled thermodynamic analysis module is used to solve the transient heat-fluid-solid coupling of the CFD calculation model and the finite element mesh model to obtain the transient temperature field and thermal flow field; perform thermal stress calculation based on the transient temperature field, thermal flow field and stress-strain field to obtain the total stress field; perform extreme temperature thermodynamic performance evaluation based on the transient temperature field, thermal flow field and total stress field to obtain thermodynamic performance indicators; The multi-objective robust optimization module is used to perform multi-objective robust optimization based on thermodynamic performance indicators, fluid dynamics parameters and stress-strain fields to obtain the optimal design scheme of the ball valve.

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