Method and apparatus for determining profile of valve plug of control valve

Abstract

Disclosed in the present invention are a method and apparatus for determining the profile of a valve plug of a control valve. The method comprises: determining main parameters for the calculation of a valve plug of a control valve, wherein the main parameters comprise a flow characteristic type, a valve size, a flow regime type, a computational boundary, and a boundary layer treatment mode; on the basis of the flow characteristic type, selecting a theoretical calculation mathematical model for valve plug design, and on the basis of the mathematical model and the main parameters, calculating a theoretical profile of the valve plug and theoretical values of a flow characteristic of the control valve at different opening degrees; on the basis of the valve size of the control valve and the theoretical profile of the valve plug, constructing three-dimensional models of the control valve at different opening degrees; for a three-dimensional model of the control valve at each opening degree, extracting a three-dimensional fluid domain model at the opening degree from the three-dimensional model of the control valve, performing meshing on the three-dimensional fluid domain model, and on the basis of CFD simulation, performing simulation calculation on the three-dimensional fluid domain model, which has been subjected to meshing, so as to obtain a simulation value of the flow characteristic of the control valve under the theoretical profile and the opening degree; and on the basis of the difference between the theoretical value and the simulation value at each opening degree, correcting the theoretical profile of the valve plug to obtain a corrected profile of the valve plug. By means of the present application, the design cycle of a valve plug can be shortened, and the designed valve plug has a better flow characteristic.

Description

A method and apparatus for determining the profile of a control valve core Technical Field

[0001] This invention relates to the field of valve design technology, and in particular to a method and apparatus for determining the profile of a control valve core. Background Technology

[0002] The design of the valve core of a control valve directly affects its flow characteristics. Therefore, designing a suitable valve core profile is particularly important for the flow characteristics of the control valve.

[0003] Currently, in valve core design, after obtaining the theoretical profile, the relevant technologies primarily rely on extensive experimentation to refine it. This method requires prototyping, followed by repeated testing to determine design deviations. Once adjustments are made to these deviations, new prototyping specimens are needed for testing and verification of the optimized design. On one hand, this method involves a lengthy prototyping cycle, leading to prolonged valve development, high development costs, and a risk of missing market opportunities. On the other hand, control valve flow testing platforms use water as the testing medium. After testing, even with cleaning and drying, valve samples cannot be used with liquid helium or liquid nitrogen, rendering the prototyping unusable and resulting in high economic costs for testing and verification.

[0004] Therefore, there is an urgent need for a method and device for determining the profile of the control valve core to solve the above problems. Summary of the Invention

[0005] This invention provides a method and apparatus for determining the profile of a control valve spool, which can significantly shorten the valve spool design cycle and result in a valve spool with better flow characteristics. The technical solution is as follows:

[0006] Firstly, a method for determining the profile of a control valve spool is provided, the method comprising:

[0007] Based on the application scenarios of control valves, the main parameters for calculating the control valve core are determined; the main parameters include: flow characteristic type, diameter, flow regime type, calculation boundary, and boundary layer processing method;

[0008] Based on the types of flow characteristics, a theoretical mathematical model for valve core design is selected, and the theoretical profile of the valve core and the theoretical values ​​of the flow characteristics of the control valve at different opening degrees are calculated based on the mathematical model and the main parameters.

[0009] Based on the valve's orifice diameter and the valve core's theoretical profile, a three-dimensional model of the valve under different opening degrees is constructed.

[0010] For each opening degree of the control valve 3D model, the following steps are performed: extract the fluid domain 3D model at that opening degree from the control valve 3D model and mesh the fluid domain 3D model; perform simulation calculations on the meshed fluid domain 3D model based on CFD simulation technology to obtain the simulated values ​​of the flow characteristics of the control valve at that theoretical profile and opening degree.

[0011] Based on the difference between the theoretical and simulated values ​​at each opening degree, the theoretical profile of the valve core is corrected until the corrected valve core profile is obtained.

[0012] Secondly, a device for determining the profile of a regulating valve core is provided, the device comprising:

[0013] The determination unit is used to determine the main parameters for calculating the control valve core based on the application scenario of the control valve; the main parameters include: flow characteristic type, diameter, flow regime type, calculation boundary and boundary layer processing method;

[0014] The calculation unit is used to select a theoretical calculation mathematical model for valve core design based on the type of flow characteristics, and to calculate the theoretical profile of the valve core and the theoretical values ​​of the flow characteristics of the control valve at different opening degrees based on the mathematical model and the main parameters.

[0015] A construction unit is used to construct a three-dimensional model of the control valve under different opening degrees based on the valve's orifice diameter and the theoretical profile of the valve core.

[0016] The simulation unit is used to perform the following for each opening degree of the three-dimensional model of the control valve: extract the three-dimensional model of the fluid domain at that opening degree from the three-dimensional model of the control valve, and mesh the three-dimensional model of the fluid domain; perform simulation calculations on the meshed three-dimensional model of the fluid domain based on CFD simulation technology to obtain the simulated values ​​of the flow characteristics of the control valve at that theoretical profile and opening degree.

[0017] The correction unit is used to correct the theoretical profile of the valve core based on the difference between the theoretical value and the simulated value at each opening degree, until the corrected valve core profile is obtained.

[0018] Thirdly, embodiments of the present invention also provide an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, it implements the method described in any embodiment of this specification.

[0019] Fourthly, a computer-readable storage medium is provided, wherein a computer program is stored therein, and when executed by a processor, the computer program implements the steps of the method for determining the valve core profile of the control valve described above.

[0020] Fifthly, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps of the method for determining the valve core profile of the control valve described above.

[0021] This invention provides a method for determining the valve core profile of a control valve. First, a theoretical mathematical model is determined based on the type of flow characteristics. Then, based on this mathematical model, the theoretical valve core profile and theoretical values ​​of flow characteristics at various opening degrees are calculated. Next, based on the theoretical valve core profile, a three-dimensional model of the control valve is constructed, and three-dimensional models of the fluid domain at different opening degrees are extracted. The extracted fluid domain is then meshed, and CFD simulation technology is used to simulate and calculate the meshed fluid domain, obtaining simulated values ​​of the control valve's flow characteristics. Since the simulated values ​​can characterize the flow characteristics of the valve core's theoretical profile in practical applications, the difference between the simulated and theoretical values ​​can be used to judge the quality of the valve core's theoretical profile. The theoretical valve core profile is then corrected based on this difference until both the theoretical and simulated values ​​show good performance, resulting in a corrected valve core profile. Therefore, this method does not require the fabrication of a real prototype; it only requires multiple theoretical calculations and simulations to obtain a valve core that meets the flow characteristic requirements. This significantly shortens the valve core design cycle, and the designed valve core exhibits good flow characteristics. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 is a flowchart of a method for determining the profile of a regulating valve core according to an embodiment of the present invention;

[0024] Figure 2 is a structural diagram of a device for determining the profile of a regulating valve core according to an embodiment of the present invention;

[0025] Figure 3 is a hardware architecture diagram of a computer device provided in an embodiment of the present invention;

[0026] Figure 4 is a schematic diagram of the mesh independence verification effect provided by an embodiment of the present invention;

[0027] Figure 5 is a schematic diagram of different grid shapes provided in an embodiment of the present invention;

[0028] Figure 6 is a partial structural diagram of a sub-region provided in an embodiment of the present invention;

[0029] Figure 7 is a schematic diagram of the mesh before optimization provided in an embodiment of the present invention;

[0030] Figure 8 is a schematic diagram of an optimized mesh provided in an embodiment of the present invention;

[0031] Figure 9 is a velocity cloud map before optimization provided in an embodiment of the present invention;

[0032] Figure 10 is an optimized velocity cloud map provided in an embodiment of the present invention;

[0033] Figure 11 is a residual curve provided in an embodiment of the present invention;

[0034] Figure 12 is an outlet mass flow rate curve provided by an embodiment of the present invention;

[0035] Figure 13 is an inlet and outlet mass flow rate curve provided in an embodiment of the present invention;

[0036] Figure 14 is an outlet volume flow rate curve provided by an embodiment of the present invention;

[0037] Figure 15 is a velocity field distribution cloud map provided in an embodiment of the present invention;

[0038] Figure 16 is a streamline diagram provided in an embodiment of the present invention;

[0039] Figure 17 is a pressure field distribution cloud map provided in an embodiment of the present invention;

[0040] Figure 18 is a comparison chart of the calculation results of the method of this application and the existing method according to an embodiment of the present invention. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0042] The following describes the specific implementation of the above concept.

[0043] Please refer to Figure 1. An embodiment of the present invention provides a method for determining the profile of a regulating valve core. The method includes:

[0044] Step 100: Based on the application scenario of the control valve, determine the main parameters for calculating the control valve core; the main parameters include: flow characteristic type, diameter, flow regime type, calculation boundary and boundary layer processing method;

[0045] Step 102: Based on the type of flow characteristics, select the theoretical calculation mathematical model for valve core design, and calculate the theoretical profile of valve core and the theoretical values ​​of flow characteristics of control valve under different opening degrees based on the mathematical model and main parameters.

[0046] Step 104: Based on the valve's diameter and the theoretical profile of the valve core, construct a three-dimensional model of the control valve under different opening degrees.

[0047] Step 106: For each opening degree of the control valve 3D model, perform the following: extract the fluid domain 3D model of the opening degree from the control valve 3D model and mesh the fluid domain 3D model; perform simulation calculations on the meshed fluid domain 3D model based on CFD simulation technology to obtain the simulated values ​​of the flow characteristics of the control valve at the theoretical profile and the opening degree.

[0048] Step 108: Based on the difference between the theoretical and simulated values ​​at each opening degree, the theoretical profile of the valve core is corrected until the corrected valve core profile is obtained.

[0049] In this embodiment, a theoretical mathematical model is first determined based on the types of flow characteristics. This model is then used to calculate the theoretical profile of the valve core and the theoretical values ​​of the flow characteristics at various opening degrees. Next, based on the theoretical valve core profile, a three-dimensional model of the control valve is constructed, and three-dimensional models of the fluid domain at different opening degrees are extracted. The extracted fluid domain is then meshed, and CFD simulation technology is used to perform simulation calculations on the meshed fluid domain to obtain simulated values ​​of the control valve's flow characteristics. Since the simulated values ​​can characterize the flow characteristics of the valve core's theoretical profile in practical applications, the difference between the simulated and theoretical values ​​can be used to judge the quality of the valve core's theoretical profile. The valve core's theoretical profile is then corrected based on this difference until both the theoretical and simulated values ​​show good performance, resulting in a corrected valve core profile. Therefore, the method of this application does not require the fabrication of a real prototype; it only requires multiple theoretical calculations and simulations to obtain a valve core that meets the flow characteristic requirements. This significantly shortens the valve core design cycle, and the designed valve core exhibits good flow characteristics.

[0050] The following describes how each step shown in Figure 1 is performed.

[0051] First, for step 100, based on the application scenario of the control valve, the main parameters for calculating the control valve core are determined.

[0052] In this step, the types of flow characteristics mainly include: linear flow characteristics, equal percentage flow characteristics, and fast-opening flow characteristics; different flow characteristics correspond to different theoretical calculation mathematical models.

[0053] For example, when the flow rate change of the control valve is small, i.e., less than the flow threshold, a linear flow characteristic is selected; when the flow rate change of the control valve is large, i.e., greater than the flow threshold, an equal percentage flow characteristic is selected; when the response speed of the control valve is required to be greater than the preset speed, i.e., the control valve needs to meet the condition of rapid response, a fast-opening flow characteristic is selected. Users can select the appropriate flow characteristic type according to the actual application scenario of the control valve.

[0054] Furthermore, the valve's orifice diameter is determined based on the pipeline resistance and the maximum flow rate to be controlled. Additionally, the calculation boundaries include the medium's inlet, outlet, and wall surface. When the control valve has a symmetrical structure, the plane of symmetry is also included.

[0055] It should also be noted that the flow regime includes laminar and turbulent states. Due to the throttling characteristics of the control valve, the turbulent state is selected here. The boundary layer treatment corresponds to the turbulent state and will not be elaborated here.

[0056] For step 102, this step uses the equal percentage flow characteristic and the corresponding theoretical mathematical model, such as the curve envelope calculation method, to derive the mathematical model of the valve core profile curve. This mathematical model is a commonly used model in this field and will not be elaborated here. The theoretical valve core profile calculated by the mathematical model serves as the basis for subsequent simulation calculations, and the theoretical value of the calculated flow characteristic serves as a reference for the simulation calculation results.

[0057] Furthermore, the number of opening degrees can be determined according to user needs, such as 12 opening degrees including 3%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100%. Understandably, the more opening degrees there are, the more accurate the calculation results will be, but the amount of calculation will also increase significantly.

[0058] For step 104, based on the valve's diameter and the theoretical profile of the valve core, a three-dimensional model of the control valve under different opening degrees is constructed.

[0059] In this step, the three-dimensional model of the control valve consists of a valve core model and a valve body model. Therefore, after designing the theoretical profile of the valve core, a three-dimensional model of the valve core can be generated and assembled into the designed three-dimensional model of the valve body to form a complete three-dimensional model of the control valve.

[0060] After building the 3D model of the control valve, adjust the 3D model of the control valve to the required opening degree by adjusting the opening height of the valve core.

[0061] Regarding step 106, the concept of fluid domain is first introduced: fluid domain is the area through which the medium flows inside the valve when the valve core is opened.

[0062] In some implementations, the fluid domain range at each opening degree is determined as follows:

[0063] The fluid domain has well-defined boundaries, and each boundary has physical parameters that meet the requirements; these physical parameters include mass flow rate, pressure, and velocity.

[0064] There is no backflow at the outlet of the fluid domain and the fluid domain meets the boundary stability requirements.

[0065] In this step, the fluid domain has a clearly defined start and end point. When determining the scope of the fluid domain, it's necessary to analyze whether there are reasonable boundary conditions at the boundary and whether these conditions match the physical problem being analyzed. The boundary of the computational domain should be determined at a location with reasonable data. Secondly, it's crucial to analyze whether the problem can be simplified to a two-dimensional or axisymmetric problem. To ensure the accuracy and reference value of the fluid dynamics calculations of the medium within the control valve, the fluid boundary stability requirements must also be met when determining the computational scope of the fluid domain. Fluid flow within a pipe is generally referred to as pipe flow. The flow field gradually transitions from the initial stage at the inlet to a more stable, fully developed stage as the flow state changes. Therefore, the selected fluid domain needs to ensure that the medium is in the fully developed stage; that is, the fluid domain includes not only the internal cavity of the valve but also the valve's inlet and outlet pipes. For example, the length of the inlet pipe should be 10 times the valve diameter, and the length of the outlet pipe should be 5 times the valve diameter. After obtaining the flow field calculation results, observe whether there is backflow at the flow field outlet. If there is no backflow, it is reasonable and the flow field is complete. If there is backflow, then gradually adjust the length of the inlet and outlet pipes to the appropriate length.

[0066] In some implementations, meshing is performed on the three-dimensional model of the fluid domain, including:

[0067] Step A1: Based on the flow direction and flow characteristics of the medium in the fluid domain, the fluid domain is divided into multiple continuous sub-regions; each sub-region includes at least an inlet pipe region, an outlet pipe region, and an inlet / outlet pipe intersection region.

[0068] Step A2: For each sub-region, determine its grid size and grid shape based on the severity of the flow field parameter changes and its geometry within that sub-region.

[0069] Step A3: Divide the sub-region into grids based on grid size and grid shape.

[0070] In this step, the process of discretizing the fluid domain requires specific analysis at each location. For example, locations where geometric or physical parameters change drastically need to be finer-gridd, while locations with relatively gentle physical or geometric parameters can use a slightly sparser grid. Furthermore, in the initial stage of the simulation, as shown in Figure 4, the specific number of grid cells can be determined simultaneously by checking grid independence.

[0071] Based on the above principles, this application first divides the fluid domain into multiple sub-regions, and then adopts different mesh shapes and mesh numbers based on the geometric dimensions and medium flow characteristics of each sub-region, thereby maximizing the rational allocation of computing resources, obtaining reasonable calculation results, and promoting the rapid development of the flow characteristics of control valves.

[0072] The implementation process of step A2 is described in detail below.

[0073] In some implementations, for each sub-region, the grid size and grid shape are determined based on the drastic changes in the flow field parameters within that sub-region and its geometry, including:

[0074] B1, based on the degree of change of flow field parameters in each sub-region, the size of the grid is reduced in ascending order;

[0075] B2, for sub-regions where the drastic change in flow field parameters exceeds the first preset value, and for sub-regions where the grid lines are consistent with the direction of medium flow, a quadrilateral grid or a hexahedral grid is used;

[0076] B3, for grids where the drastic change in flow field parameters is less than the second preset value, and for sub-regions where the grid lines are not consistent with the direction of medium flow, a tetrahedral grid is used; the second preset value is less than the first preset value;

[0077] B4 uses a hexahedral grid for the inlet and outlet pipe areas;

[0078] B5 uses a tetrahedral grid for the intersection area of ​​inlet and outlet pipes;

[0079] B6 uses a pyramid-shaped pentahedral mesh for sub-regions transitioning from hexahedral to tetrahedral meshes.

[0080] Mesh generation is a crucial step in this process, as mesh quality directly impacts computational accuracy and efficiency. For complex problems, mesh generation is extremely time-consuming and error-prone, sometimes consuming up to 80% of the total computation time. Therefore, it is essential to design and generate meshes strategically to ensure required accuracy while allocating computational resources effectively to critical areas.

[0081] For the reasons mentioned above, step B1 uses the densest grid for sub-regions where the flow field parameters change drastically, and the sparsest grid for sub-regions where the flow field parameters change most gently, which can save computing power.

[0082] Furthermore, different mesh shapes directly affect the calculation results. As shown in Figure 5, these are commonly used mesh shapes, and different mesh shapes have different impacts on computing power. This embodiment, through the mesh generation methods in steps B2 to B6, can effectively reduce dissipation during the calculation process and improve the model's adaptability to complex geometries.

[0083] Furthermore, for regions where the difference in geometric dimensions between two continuous sub-regions exceeds a preset order of magnitude, discontinuous meshes can also be used. Each sub-region generates its own mesh according to its own scale, and then the two regions are connected by a discontinuous mesh interface, where physical quantities are interpolated during calculation. As shown in Figure 6, for a certain opening condition of a control valve of a certain specification, the throttling surface width d1 is only on the order of 10e-2 mm, while its downstream dimension d2 is on the order of 10e2 mm. From d1 to d2, within a region with a height h of about 1 mm, the geometric dimensions differ by four orders of magnitude. For such problems with large local size spans, discontinuous meshes can be used, starting with local refinement and gradually increasing the mesh size outwards with an appropriate gradient. The mesh should gradually decrease in density to ensure that the flow field details, such as pressure gradient, velocity gradient, and the integrity of the velocity direction change trend, can be captured completely and accurately. Otherwise, the calculation is prone to divergence.

[0084] It should also be noted that for the boundary layer mesh, due to the throttling surface causing a velocity reduction, the Reynolds number Re of the medium flow pattern usually decreases sharply at this point, approaching a laminar state. At this time, the wall effect caused by fluid viscosity is also amplified accordingly. Therefore, the mesh density is decreased sequentially in the direction away from the wall. The meshes before and after optimization are shown in Figures 7 and 8, respectively, and the velocity contour maps before and after optimization are shown in Figures 9 and 10, respectively. As can be seen from the figures, the mesh generation method proposed in this application yields more accurate flow field velocities.

[0085] In addition, in step 106, CFD simulation technology is used to perform simulation calculations on the meshed three-dimensional model of the fluid domain to obtain the simulated values ​​of the flow characteristics of the control valve under the theoretical profile and the opening degree, including:

[0086] S1, determine the input parameters for CFD simulation calculation; the input parameters include the temporal state of the three-dimensional model of the fluid domain, the type of flow regime, the fluid medium parameters, the physical parameters of the flow field to be calculated and monitored, the inlet boundary conditions, and the outlet boundary conditions;

[0087] S2, determine the initial values ​​of the current physical parameters for the current calculation round;

[0088] S3, based on the input parameters and the initial value of the current physical parameters, along the flow direction of the medium, iteratively calculates each grid in the three-dimensional model of the fluid domain according to the NS equation until the last grid is traversed, and obtains the new physical parameter value of the current calculation round;

[0089] S4, calculate the first absolute residual between the new physical parameter value and the current initial physical parameter value;

[0090] S5, determine whether the first absolute residual is not greater than the first residual threshold; if yes, execute S6; if no, use the sum of the new physical parameter value and the set step size as the initial value for the next calculation round, and return to execute S3 to S5 until the calculated first absolute residual is not greater than the first residual threshold, and then execute S6.

[0091] S6, use the new physical parameter value as the simulation value of the flow characteristics of the control valve under the theoretical profile and the opening degree.

[0092] In this embodiment, by analyzing the dimensionless parameter Re of the fluid medium flow within the regulating valve, it is determined whether the operating condition requiring CFD calculation is turbulent or laminar. The corresponding flow regime calculation model and wall function model are then input. The physical properties of the fluid medium include density, viscosity, and temperature. Boundary conditions determine the reasonableness and accuracy of the calculation results, and the physical problems of the operating condition are analyzed. Inlet boundary conditions include at least one of inlet pressure, inlet velocity, and inlet mass flow rate; outlet boundary conditions include at least one of outlet pressure, outlet velocity, outlet mass flow rate, and free outlet. Wall conditions include moving without slip and slip, etc. When uncertain, the calculation results of several schemes can be compared to determine the most reasonable scheme.

[0093] Furthermore, for each opening degree, steps S1 to S6 can be used until the calculation converges, yielding the simulation results of the flow characteristics at that opening degree. The formula for calculating the first absolute residual is |Q1-Q0|, where Q0 is the initial value of the physical parameters at the start of this calculation, and Q1 is the new value of the physical parameters obtained in this calculation. When the absolute residual is less than the set first residual threshold, the calculation is considered converged. The first residual threshold can be 1e-3. Of course, the relative residual can also be used as the convergence criterion. The formula for calculating the relative residual is: |Q1-Q0| / Q1. In addition, even if the residual does not reach the set value, as long as the physical quantity of interest (such as temperature, mass flow rate, velocity, etc.) is very stable, convergence can also be considered. As shown in Figure 11-14, the obtained residual curve, outlet mass flow rate curve, inlet and outlet mass flow rate curves, and outlet volumetric flow rate curve can be used as the convergence criterion.

[0094] It should also be noted that the simulation results output by CFD calculations mainly include the following:

[0095] (1) Velocity-related: velocity field distribution cloud map, velocity magnitude cloud map, vector streamline map, streamline map, contour map, etc.;

[0096] (2) Pressure-related: Pressure field distribution cloud map, pressure distribution contour map, etc.;

[0097] (3) Flow-related: average mass flow rate of inlet, average mass flow rate of outlet, etc.

[0098] The schematic diagrams of the velocity field distribution cloud map, streamline map, and pressure field distribution cloud map are shown in Figures 15-17, respectively.

[0099] Finally, regarding step 108, the simulation results at each opening degree are organized and analyzed. Data can generally be extracted using color contour maps, contour plots, streamline diagrams, and numerical reports of specific physical quantities, such as inlet and outlet mass flow rates, average velocity, and inlet and outlet pressures. The extracted data can demonstrate whether the global flow regime is reasonable, whether separation has occurred in certain regions, and whether key flow characteristics have been accurately calculated. Specific analysis requires a foundation in fluid mechanics, and quantitative analysis of specific physical quantities is necessary. The calculation model of this invention can extract parameters such as outlet mass flow rate and inlet and outlet average pressure, summarize and plot the flow characteristic curve of the regulating valve, and compare it with theoretical values. When the second absolute residual at all opening degrees is less than the second residual threshold (e.g., ±5%), the corrected theoretical valve core profile can be used as the corrected valve core profile.

[0100] It should be noted that after a simulation calculation, if the deviations between the simulation results for openings from 40% to 100% and the theoretical simulation results all meet the requirements, the valve core profile can be corrected based on the simulation results for a smaller opening of 30%. For the corrected valve core, theoretical and simulation calculations are then performed again for openings from 0% to 30%, until each opening meets the requirements. This is because the valve core profile has a relatively small impact on the total throttling surface of the fluid domain; adjusting the valve core profile has a negligible impact on the flow characteristics at large openings. This optimization method can significantly improve the correction speed while ensuring calculation accuracy. Of course, users can also recalculate for all openings; this application does not impose specific limitations.

[0101] To verify the effectiveness of the method proposed in this application, the inventors compared the deviations of the calculation results of the proposed method and the calculation results of existing methods from the theoretical results at various valve opening degrees (0-100%), as shown in Figure 18. The figure shows that the deviations between the calculation results of existing methods and theoretical results are 5% to 28%, while the deviations between the calculation results of the proposed method and theoretical results are ±5%.

[0102] Therefore, it can be seen that the method of this application can significantly improve the calculation accuracy of the valve core profile.

[0103] It should also be noted that after correcting the theoretical profile through CFD simulation, its flow characteristics can be verified through experiments. If the experimental results do not meet the requirements, the theoretical and CFD calculations are repeated using the method described in this application to obtain a new valve core profile, until the experimental results meet the requirements, thus obtaining the final valve core profile. This approach yields a valve core profile with more accurate control precision, achieving the design goals for the flow characteristics of the regulating valve, improving the prototype verification pass rate, and reducing development costs.

[0104] As shown in Figures 2 and 3, this embodiment of the invention provides a device for determining the valve core profile of a regulating valve. The device can be implemented in software, hardware, or a combination of both. From a hardware perspective, Figure 2 shows a hardware architecture diagram of the computing device housing the device for determining the valve core profile of a regulating valve provided in this embodiment. Besides the processor, memory, network interface, and non-volatile memory shown in Figure 2, the computing device in this embodiment may also include other hardware, such as a forwarding chip responsible for processing packets. Taking software implementation as an example, as shown in Figure 3, as a logical device, it is formed by the CPU of the computing device reading the corresponding computer program from the non-volatile memory into memory and running it.

[0105] Please refer to Figure 3. An embodiment of the present invention provides a device for determining the profile of a regulating valve core. The device includes:

[0106] Unit 300 is used to determine the main parameters for calculating the control valve core based on the application scenario of the control valve. The main parameters include: flow characteristic type, diameter, flow regime type, calculation boundary and boundary layer processing method.

[0107] The calculation unit 302 is used to select the theoretical calculation mathematical model for valve core design based on the type of flow characteristics, and to calculate the theoretical profile of valve core and the theoretical value of flow characteristics of control valve under different opening degrees based on the mathematical model and main parameters.

[0108] Building unit 304 is used to construct a three-dimensional model of the control valve under different opening degrees based on the valve's orifice diameter and the theoretical profile of the valve core.

[0109] Simulation unit 306 is used to perform the following for each opening degree of the control valve 3D model: extract the fluid domain 3D model at that opening degree from the control valve 3D model and mesh the fluid domain 3D model; perform simulation calculations on the meshed fluid domain 3D model based on CFD simulation technology to obtain the simulated values ​​of the flow characteristics of the control valve at the theoretical profile and the opening degree.

[0110] The correction unit 308 is used to correct the theoretical profile of the valve core based on the difference between the theoretical value and the simulation value at each opening degree, until the corrected valve core profile is obtained.

[0111] In some implementations, the orifice is determined based on the pipeline resistance of the control valve and the maximum flow rate that needs to be controlled;

[0112] The computational boundary includes the medium's inlet, outlet, and wall.

[0113] In some implementations, meshing is performed on the three-dimensional model of the fluid domain, including:

[0114] Based on the flow direction and flow characteristics of the medium in the fluid domain, the fluid domain is divided into multiple continuous sub-regions; each sub-region includes at least an inlet pipe region, an outlet pipe region, and an inlet / outlet pipe intersection region.

[0115] For each sub-region, the grid size and grid shape are determined based on the severity of the flow field parameter changes and the geometry within that sub-region.

[0116] The sub-region is divided into grids based on grid size and grid shape.

[0117] In some implementations, for each sub-region, the grid size and grid shape are determined based on the drastic changes in the flow field parameters within that sub-region and its geometry, including:

[0118] Based on the degree of drastic change in flow field parameters within each sub-region, the grid size is decreased sequentially in ascending order;

[0119] For sub-regions where the drastic changes in flow field parameters exceed the first preset value, and for sub-regions where the grid lines are aligned with the direction of medium flow, quadrilateral or hexahedral grids are used.

[0120] For grids where the drastic change in flow field parameters is less than the second preset value, and for sub-regions where the grid lines are not aligned with the direction of medium flow, tetrahedral grids are used; the second preset value is less than the first preset value.

[0121] A hexahedral grid is used for the inlet pipe area and the outlet pipe area;

[0122] Tetrahedral meshes are used in the areas where inlet and outlet pipes intersect.

[0123] For sub-regions transitioning from hexahedral to tetrahedral meshes, a pyramid-shaped pentahedral mesh is used.

[0124] In some implementations, the fluid domain range at each opening degree is determined as follows:

[0125] The fluid domain has well-defined boundaries, and each boundary has physical parameters that meet the requirements; these physical parameters include mass flow rate, pressure, and velocity.

[0126] There is no backflow at the outlet of the fluid domain and the fluid domain meets the boundary stability requirements.

[0127] In some implementations, CFD simulation technology is used to perform simulation calculations on the meshed three-dimensional model of the fluid domain to obtain simulated values ​​of the flow characteristics of the control valve under the theoretical profile and opening degree, including:

[0128] S1, determine the input parameters for CFD simulation calculation; the input parameters include the temporal state of the three-dimensional model of the fluid domain, the type of flow regime, the fluid medium parameters, the physical parameters of the flow field to be calculated and monitored, the inlet boundary conditions, and the outlet boundary conditions;

[0129] S2, determine the initial values ​​of the current physical parameters for the current calculation round;

[0130] S3, based on the input parameters and the initial value of the current physical parameters, along the flow direction of the medium, iteratively calculates each grid in the three-dimensional model of the fluid domain according to the NS equation until the last grid is traversed, and obtains the new physical parameter value of the current calculation round;

[0131] S4, calculate the first absolute residual between the new physical parameter value and the current initial physical parameter value;

[0132] S5, determine whether the first absolute residual is not greater than the first residual threshold; if yes, execute S6; if no, use the sum of the new physical parameter value and the set step size as the initial value for the next calculation round, and return to execute S3 to S5 until the calculated first absolute residual is not greater than the first residual threshold, and then execute S6.

[0133] S6, use the new physical parameter value as the simulation value of the flow characteristics of the control valve under the theoretical profile and the opening degree.

[0134] In some implementations, the correction unit 308 is used to perform the following operations:

[0135] S7, calculate the second absolute residual between the theoretical value and the simulated value for each opening degree, and determine whether there is at least one second absolute residual greater than the second residual threshold; if there is, proceed to S8; if not, proceed to S9.

[0136] S8: Select the largest opening from the openings corresponding to second absolute residuals greater than the second residual threshold; based on the simulation results corresponding to the largest opening, recalculate the new theoretical profile of the valve core and the new theoretical results corresponding to the new theoretical profile using the mathematical model; for the largest opening and other openings smaller than the largest opening, re-execute: extract the three-dimensional model of the fluid domain under this opening from the three-dimensional model of the control valve, and mesh the three-dimensional model of the fluid domain; re-simulate the three-dimensional model of the meshed fluid domain based on CFD simulation technology to obtain new simulation values ​​of the flow characteristics of the control valve under the new theoretical profile and this opening; for the new theoretical values ​​and the new simulation values, re-execute S7 and S8 until the second absolute residual corresponding to each opening is no greater than the second residual threshold, and then execute S9;

[0137] S9 uses the final theoretical profile of the valve core as the final profile of the valve core.

[0138] It should be noted that the device for determining the valve core profile of the regulating valve provided in the above embodiments is only an example of the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the device for determining the valve core profile of the regulating valve provided in the above embodiments and the method embodiment for determining the valve core profile of the regulating valve belong to the same concept. For details of its implementation process, please refer to the method embodiment, which will not be repeated here.

[0139] The embodiments of this application also provide a computer device, as shown in FIG3. The computer device includes a processor and a memory. The memory stores at least one instruction, at least one program, code set or instruction set. The at least one instruction, at least one program, code set or instruction set is loaded and executed by the processor to implement the method for determining the valve core profile of the regulating valve provided in the above method embodiments.

[0140] Embodiments of this application also provide a computer-readable storage medium storing at least one instruction, at least one program, code set, or instruction set, wherein the at least one instruction, at least one program, code set, or instruction set is loaded and executed by a processor to implement the method for determining the valve core profile of the regulating valve provided in the above-described method embodiments.

[0141] Embodiments of this application also provide a computer program product, which includes a computer program. A processor of a computer device reads the computer program from a computer-readable storage medium and executes the computer program, causing the computer device to perform the method for determining the valve core profile of the regulating valve as described in any of the above embodiments.

[0142] For ease of description, the above systems or devices are described separately as various modules or units based on their functions. Of course, in implementing this application, the functions of each unit can be implemented in one or more software and / or hardware components.

[0143] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that this application can be implemented by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in various embodiments or some parts of the embodiments of this application.

[0144] Finally, it should be noted that in this document, relational terms such as first, second, third, and fourth are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0145] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method of determining a profile of a valve trim of a regulating valve, characterized by, The method includes: Based on the application scenarios of control valves, the main parameters for calculating the control valve core are determined; the main parameters include: flow characteristic type, diameter, flow regime type, calculation boundary, and boundary layer processing method; Based on the types of flow characteristics, a theoretical mathematical model for valve core design is selected, and the theoretical profile of the valve core and the theoretical values ​​of the flow characteristics of the control valve at different opening degrees are calculated based on the mathematical model and the main parameters. Based on the valve's orifice diameter and the valve core's theoretical profile, a three-dimensional model of the valve under different opening degrees is constructed. For each opening degree of the control valve 3D model, the following steps are performed: extract the fluid domain 3D model at that opening degree from the control valve 3D model and mesh the fluid domain 3D model; perform simulation calculations on the meshed fluid domain 3D model based on CFD simulation technology to obtain the simulated values ​​of the flow characteristics of the control valve at that theoretical profile and opening degree. Based on the difference between the theoretical and simulated values ​​at each opening degree, the theoretical profile of the valve core is corrected until the corrected valve core profile is obtained.

2. The method of claim 1, wherein, The diameter is determined based on the pipeline resistance of the regulating valve and the maximum flow rate that needs to be controlled; The computational boundary includes the medium's inlet, outlet, and wall surface.

3. The method of claim 1, wherein, Mesh generation of the 3D model of the fluid domain includes: Based on the flow direction and flow characteristics of the medium in the fluid domain, the fluid domain is divided into multiple continuous sub-regions; the sub-regions include at least an inlet pipe region, an outlet pipe region, and an inlet / outlet pipe intersection region. For each sub-region, the grid size and grid shape are determined based on the severity of the flow field parameter changes and the geometry within that sub-region. The sub-region is divided into grids based on the grid size and the grid shape.

4. The method of claim 3, wherein, For each sub-region, the grid size and grid shape are determined based on the severity of the flow field parameter changes and its geometry within that sub-region, including: Based on the degree of drastic change in flow field parameters within each sub-region, the grid size is decreased sequentially in ascending order; For sub-regions where the drastic changes in flow field parameters exceed the first preset value, and for sub-regions where the grid lines are aligned with the direction of medium flow, quadrilateral or hexahedral grids are used. For grids where the drastic change in flow field parameters is less than the second preset value, and for sub-regions where the grid lines are not consistent with the direction of medium flow, a tetrahedral grid is used; the second preset value is less than the first preset value. A hexahedral mesh is used for the inlet pipe area and the outlet pipe area; A tetrahedral mesh is used for the intersection area of ​​the inlet and outlet pipes; For sub-regions transitioning from hexahedral to tetrahedral meshes, a pyramid-shaped pentahedral mesh is used.

5. The method of claim 3, wherein, The fluid domain range at each opening degree is determined as follows: The fluid domain has well-defined boundaries, and each boundary has physical parameters that meet the requirements; the physical parameters include mass flow rate, pressure, and velocity. The fluid domain has no backflow at the flow field outlet and the fluid domain meets the boundary stability requirements.

6. The method of claim 1, wherein, The CFD simulation technology is used to perform simulation calculations on the meshed three-dimensional fluid domain model to obtain simulated values ​​of the flow characteristics of the control valve under the theoretical profile and opening degree, including: S1, determine the input parameters for CFD simulation calculation; the input parameters include the temporal state of the three-dimensional model of the fluid domain, the type of flow regime, the fluid medium parameters, the physical parameters of the flow field to be calculated and monitored, the inlet boundary conditions, and the outlet boundary conditions; S2, determine the initial values ​​of the current physical parameters for the current calculation round; S3, based on the input parameters and the initial value of the current physical parameters, along the direction of medium flow, iteratively calculate each grid in the three-dimensional model of the fluid domain according to the NS equation until the last grid is traversed, and obtain the new physical parameter value of the current calculation round; S4, calculate the first absolute residual between the new physical parameter value and the current initial physical parameter value; S5, determine whether the first absolute residual is not greater than the first residual threshold; if yes, execute S6; if no, use the sum of the new physical parameter value and the set step size as the initial value for the next calculation round, and return to execute S3 to S5 until the calculated first absolute residual is not greater than the first residual threshold, and then execute S6. S6, use the new physical parameter value as the simulation value of the flow characteristics of the control valve under the theoretical profile and the opening degree.

7. The method of claim 6, wherein, The process of correcting the theoretical profile of the valve core based on the difference between the theoretical and simulated values ​​at each opening degree until a corrected valve core profile is obtained includes: S7, calculate the second absolute residual between the theoretical value and the simulated value for each opening degree, and determine whether there is at least one second absolute residual greater than the second residual threshold; if there is, proceed to S8; if not, proceed to S9. S8: Select the largest opening from the openings corresponding to second absolute residuals greater than the second residual threshold; based on the simulation results corresponding to the largest opening, recalculate the new theoretical profile of the valve core and the new theoretical results corresponding to the new theoretical profile using the mathematical model; for the largest opening and other openings smaller than the largest opening, re-execute: extract the three-dimensional fluid domain model under the opening from the three-dimensional model of the control valve, and mesh the three-dimensional fluid domain model; re-simulate the meshed three-dimensional fluid domain model based on CFD simulation technology to obtain new simulation values ​​of the flow characteristics of the control valve under the new theoretical profile and the opening; for the new theoretical values ​​and the new simulation values, re-execute S7 and S8 until the second absolute residual corresponding to each opening is no greater than the second residual threshold, and then execute S9; S9 uses the final theoretical profile of the valve core as the final profile of the valve core.

8. A device for determining the profile of a regulating valve spool, characterized in that The device includes: The determination unit is used to determine the main parameters for calculating the control valve core based on the application scenario of the control valve; the main parameters include: flow characteristic type, diameter, flow regime type, calculation boundary and boundary layer processing method; The computing unit is configured to select a theoretical calculation mathematical model of the valve core design based on the flow characteristic category, and calculate a theoretical profile of the valve core based on the mathematical model and the main parameters, and adjust theoretical values of the flow characteristics of the regulating valve at different opening degrees; The constructing unit is configured to construct a three-dimensional model of the regulating valve at different opening degrees based on the caliber of the regulating valve and the theoretical profile of the valve core; The simulation unit is configured to, for the three-dimensional model of the regulating valve at each opening degree, extract a three-dimensional model of a fluid domain at the opening degree from the three-dimensional model of the regulating valve, and perform meshing on the three-dimensional model of the fluid domain; perform simulation calculation on the three-dimensional model of the fluid domain after meshing based on a CFD simulation technology, to obtain simulation values of the flow characteristics of the regulating valve at the theoretical profile and the opening degree. The correcting unit is configured to correct the theoretical profile of the valve core based on differences between the theoretical values and the simulation values at each opening degree, until a corrected valve core profile is obtained.

9. A computer device, comprising: The computer device comprises a memory and a processor, the memory is used to store a computer program, and the processor is used to execute the computer program stored on the memory to realize the steps of the method of any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The storage medium stores a computer program, and the computer program is executed by the processor to realize the steps of the method of any one of claims 1-7.

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