Method and device for determining molded line of valve element of regulating valve

Abstract

The invention discloses a method and a device for determining a molded line of a valve core of a regulating valve. The method comprises the following steps: determining main parameters for calculating the valve core of the regulating valve; the main parameters comprise a flow characteristic type, a caliber, a flow state type, a calculation boundary and a processing mode of a boundary layer; selecting a theoretical calculation mathematical model of valve core design based on the flow characteristic type, and calculating a theoretical molded line of the valve core and theoretical values of the flow characteristics under different opening degrees based on the mathematical model and the main parameters; based on the caliber of the regulating valve and the theoretical molded line of the valve element, constructing a three-dimensional model of the regulating valve under different opening degrees; for the three-dimensional model of the regulating valve under each opening degree, extracting a three-dimensional model of a fluid domain under the opening degree from the three-dimensional model of the regulating valve, and performing grid division on the three-dimensional model of the fluid domain; performing simulation calculation on the fluid domain three-dimensional model after grid division based on CFD simulation to obtain a simulation value of the flow characteristic of the regulating valve under the theoretical molded line; and on the basis of the difference between the theoretical value and the simulation value under each opening degree, the theoretical molded line of the valve element is corrected, and the corrected molded line of the valve element is obtained. The design period of the valve element can be shortened, and the designed valve element has the good flow characteristic.

Description

Technical Field

[0001] The invention relates to the technical field of valve design, and in particular to a method and a device for determining a valve core profile of a regulating valve. Background Art

[0002] The valve core design of the 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] At present, when designing the valve core, the relevant technology mainly uses a large number of tests to correct the theoretical profile after obtaining the theoretical profile of the valve core. This method requires the production of a prototype. After the prototype is produced, the design deviation can only be obtained by repeated tests on the prototype. After the design deviation is adjusted, a new prototype test piece needs to be produced to test and verify the optimization plan. On the one hand, this method has a long waiting period for prototype production, which not only leads to a long valve development cycle and high development costs, but also easily misses market opportunities. On the other hand, the regulating valve flow test platform uses water as the test medium for testing. After the valve sample is tested, even if it is cleaned and dried, it is not allowed to be used in liquid helium, liquid nitrogen and other media scenarios, so the prototype cannot be reused, and the economic cost of test verification is also high.

[0004] Based on this, there is an urgent need for a method and device for determining the valve core profile of a regulating valve to solve the above-mentioned problem. Summary of the invention

[0005] The present invention provides a method and device for determining the profile of a regulating valve core, which can greatly shorten the design cycle of the valve core, and the designed valve core has better flow characteristics. The technical solution is as follows:

[0006] In a first aspect, a method for determining a valve core profile of a regulating valve is provided, the method comprising:

[0007] Based on the application scenario of the regulating valve, determine the main parameters for calculating the regulating valve core; the main parameters include: flow characteristic type, caliber, flow pattern type, calculation boundary and boundary layer processing method;

[0008] Based on the type of flow characteristics, a theoretical calculation mathematical model for valve core design is selected, and based on the mathematical model and the main parameters, a theoretical profile of the valve core and theoretical values ​​of flow characteristics of the regulating valve at different openings are calculated;

[0009] Based on the caliber of the regulating valve and the theoretical profile of the valve core, constructing a three-dimensional model of the regulating valve at different openings;

[0010] For each three-dimensional model of the regulating valve at each opening, the following steps are performed: extracting a three-dimensional model of the fluid domain at the opening from the three-dimensional model of the regulating valve, and meshing the three-dimensional model of the fluid domain; performing simulation calculation on the meshed three-dimensional model of the fluid domain based on CFD simulation technology to obtain a simulation value of the flow characteristic of the regulating valve at the theoretical profile and the opening;

[0011] Based on the difference between the theoretical value and the simulation value at each opening, the theoretical profile of the valve core is corrected until a corrected valve core profile is obtained.

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

[0013] A determination unit, used to determine the main parameters for calculating the valve core of the regulating valve based on the application scenario of the regulating valve; the main parameters include: flow characteristic type, caliber, flow state type, calculation boundary and boundary layer processing method;

[0014] A calculation unit, used for selecting a theoretical calculation mathematical model for valve core design based on the type of flow characteristic, and calculating a theoretical profile of the valve core and theoretical values ​​of flow characteristics of the regulating valve at different openings based on the mathematical model and the main parameters;

[0015] A construction unit, used to construct a three-dimensional model of the regulating valve at different openings based on the caliber of the regulating valve and the theoretical profile of the valve core;

[0016] The simulation unit is used to perform, for each three-dimensional model of the regulating valve at each opening degree: extracting a three-dimensional model of the fluid domain at the opening degree from the three-dimensional model of the regulating valve, and meshing the three-dimensional model of the fluid domain; performing simulation calculation on the meshed three-dimensional model of the fluid domain based on CFD simulation technology to obtain a simulation value of the flow characteristic of the regulating valve at the theoretical profile and the 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 simulation value at each opening, until a corrected valve core profile is obtained.

[0018] In a third aspect, an embodiment of the present invention further provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the method described in any embodiment of this specification is implemented.

[0019] In a fourth aspect, a computer-readable storage medium is provided, wherein a computer program is stored in the storage medium, and when the computer program is executed by a processor, the steps of the method for determining a valve core profile of a regulating valve described above are implemented.

[0020] In a fifth aspect, a computer program product is provided, comprising a computer program, which, when executed by a processor, implements the steps of the method for determining a valve core profile of a regulating valve as described above.

[0021] The embodiment of the present invention provides a method for determining the profile of a regulating valve core. First, a theoretical calculation mathematical model is determined based on the type of flow characteristic, so as to calculate the theoretical profile of the valve core and the theoretical value of the flow characteristic under each opening based on the mathematical model. Then, on the basis of the theoretical profile of the valve core, a three-dimensional model of the regulating valve is constructed, and a three-dimensional model of the fluid domain under different openings is extracted, and then the extracted fluid domain is meshed, so as to simulate and calculate the meshed fluid domain based on the CFD simulation technology to obtain the simulation value of the flow characteristic of the regulating valve. Since the simulation value can characterize the flow characteristic of the theoretical profile of the valve core in actual application, the advantages and disadvantages of the theoretical profile of the valve core can be judged based on the difference between the simulation value and the theoretical value, so as to correct the theoretical profile of the valve core based on the difference between the two, until the profile of the valve core has a good effect in both the theoretical value and the simulation value, and the corrected valve core profile is obtained. It can be seen that the method of the present application does not need to make a real prototype, but only needs to obtain a valve core that meets the flow characteristic requirements through multiple theoretical calculations and multiple simulations. Therefore, the design cycle of the valve core can be greatly shortened, and the designed valve core has a good flow characteristic. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 This is a flow chart of a method for determining a valve core profile of a regulating valve provided by an embodiment of the present invention;

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

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

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

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

[0028] Figure 6 is a schematic diagram of a local structure of a sub-region provided by an embodiment of the present invention;

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

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

[0031] Fig. 9 is a velocity cloud map before optimization provided by an embodiment of the present invention;

[0032] Fig.10 is an optimized velocity cloud map provided by an embodiment of the present invention;

[0033] Fig.11 is a residual curve diagram provided by an embodiment of the present invention;

[0034] Fig.12 is an outlet mass flow curve diagram provided by an embodiment of the present invention;

[0035] Fig.13 is an inlet and outlet mass flow curve diagram provided by an embodiment of the present invention;

[0036] Fig.14 is an outlet volume flow curve diagram provided by an embodiment of the present invention;

[0037] Fig.15 is a velocity field distribution cloud map provided by an embodiment of the present invention;

[0038] Fig.16 is a flow chart provided by an embodiment of the present invention;

[0039] Fig.17 is a pressure field distribution cloud map provided by an embodiment of the present invention;

[0040] Fig.18 It is a comparison chart of calculation results of the present application method and the existing method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0042] The specific implementation of the above concept is described below.

[0043] Please refer to Figure 1 , an embodiment of the present invention provides a method for determining a valve core profile of a regulating valve, the method comprising:

[0044] Step 100, based on the application scenario of the regulating valve, determine the main parameters for calculating the valve core of the regulating valve; the main parameters include: flow characteristic type, caliber, flow pattern type, calculation boundary and boundary layer processing method;

[0045] Step 102, based on the type of flow characteristics, select a theoretical calculation mathematical model for valve core design, and calculate the theoretical profile of the valve core and the theoretical value of the flow characteristics of the regulating valve at different openings based on the mathematical model and main parameters;

[0046] Step 104, constructing a three-dimensional model of the regulating valve at different openings based on the caliber of the regulating valve and the theoretical profile of the valve core;

[0047] Step 106, for each three-dimensional model of the regulating valve at each opening, the following steps are performed: extracting a three-dimensional model of the fluid domain at the opening from the three-dimensional model of the regulating valve, and meshing the three-dimensional model of the fluid domain; performing simulation calculation on the meshed three-dimensional model of the fluid domain based on CFD simulation technology to obtain a simulation value of the flow characteristic of the regulating valve at the theoretical profile and the opening;

[0048] Step 108 , based on the difference between the theoretical value and the simulation value at each opening, the theoretical profile of the valve core is corrected until a corrected valve core profile is obtained.

[0049] In this embodiment, firstly, a theoretical calculation mathematical model is determined based on the type of flow characteristic, so as to calculate the theoretical profile of the valve core and the theoretical value of the flow characteristic under each opening based on the mathematical model. Then, on the basis of the theoretical profile of the valve core, a three-dimensional model of the regulating valve is constructed, and the three-dimensional model of the fluid domain under different openings is extracted, and then the extracted fluid domain is meshed, so as to simulate and calculate the meshed fluid domain based on the CFD simulation technology, and obtain the simulation value of the flow characteristic of the regulating valve. Since the simulation value can characterize the flow characteristic of the valve core theoretical profile in actual application, the advantages and disadvantages of the valve core theoretical profile can be judged based on the difference between the simulation value and the theoretical value, so as to correct the theoretical profile of the valve core based on the difference between the two, until the profile of the valve core has a good effect in both the theoretical value and the simulation value, and the corrected valve core profile is obtained. It can be seen from this that the method of the present application does not need to make a real prototype, but only needs to obtain a valve core that meets the flow characteristic requirements through multiple theoretical calculations and multiple simulations, so that the design cycle of the valve core can be greatly shortened, and the designed valve core has a good flow characteristic.

[0050] Described below Figure 1 How the various steps are performed.

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

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

[0053] For example, when the flow rate of the control valve changes slightly, that is, less than the flow threshold, select the linear flow characteristic; when the flow rate of the control valve changes significantly, that is, greater than the flow threshold, select the equal percentage flow characteristic; when the response speed of the control valve is required to be greater than the preset speed, that is, the control valve needs to meet the working condition of fast response, select the fast opening flow characteristic. Users can select the appropriate flow characteristic type according to the actual application scenario of the control valve.

[0054] In addition, the caliber of the regulating valve is determined based on the pipeline resistance of the regulating valve and the maximum flow rate that needs to be controlled. In addition, the calculation boundary includes the inlet, outlet and wall of the medium. When the regulating valve is a symmetrical structure, the symmetry surface is also included.

[0055] It should also be noted that the flow states include laminar flow and turbulent flow. Due to the throttling characteristics of the regulating valve, the turbulent flow state is selected here. The boundary layer processing method corresponds to the turbulent flow state and will not be repeated here.

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

[0057] In addition, the number of openings can be determined according to user needs, such as 3%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100% and other 12 kinds of openings. It can be understood that the more the number of openings, the more accurate the calculation results, but the amount of calculation also increases significantly.

[0058] With respect to step 104 , a three-dimensional model of the regulating valve at different openings is constructed based on the caliber of the regulating valve and the theoretical profile of the valve core.

[0059] In this step, the three-dimensional model of the regulating valve is composed of the valve core model and the valve body model. Therefore, after the theoretical profile of the valve core is designed, the 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 regulating valve.

[0060] After building the three-dimensional model of the regulating valve, adjust the three-dimensional model of the regulating valve to the required opening by adjusting the opening height of the valve core.

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

[0062] In some embodiments, the fluid domain range at each opening is determined by:

[0063] The fluid domain has clear boundaries, and each boundary has physical parameters that meet the requirements; the physical parameters include mass flow, pressure and velocity;

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

[0065] In this step, the fluid domain has a clear starting position and end position, and when determining the scope of the fluid domain, it is necessary to analyze whether there is reasonable boundary condition information on the boundary, whether the boundary condition can match the physical problem to be analyzed, and determine the boundary of the calculation domain at a location with reasonable data. Secondly, analyze whether the problem can be simplified into a two-dimensional problem or an axisymmetric problem. In order to ensure that the fluid mechanics calculation and analysis results of the medium in the regulating valve are correct and have reference value, the fluid boundary stability requirements must also be met when determining the calculation range of the fluid domain. The flow of fluid in a pipeline is generally referred to as pipeline flow. The flow field gradually transitions from the initial stage of the inlet to a relatively stable fully developed stage as the flow state changes. Therefore, the intercepted 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 inlet and outlet pipelines of the valve. For example, the inlet pipe length is 10 times the valve diameter, and the outlet pipe length is 5 times the pipe diameter. After obtaining the flow field calculation results, observe whether there is backflow at the flow field outlet. It is reasonable if there is no backflow, and the flow field is complete. If there is backflow, adjust the inlet and outlet pipe lengths to the appropriate lengths step by step.

[0066] In some embodiments, meshing the fluid domain three-dimensional model includes:

[0067] Step A1, based on the flow direction and flow characteristics of the medium in the fluid domain, the fluid domain is divided into a plurality of continuous sub-regions; the sub-regions at least include an inlet pipe region, an outlet pipe region, and an inlet and outlet pipe intersection region;

[0068] Step A2, for each sub-region, determining the grid size and grid shape based on the severity of the change of the flow field parameters in the sub-region and its geometric shape;

[0069] Step A3, meshing the sub-area based on the mesh size and mesh shape.

[0070] In this step, the process of discretizing the fluid domain requires specific analysis of specific locations. For example, locations where geometric parameters or physical parameters change sharply need to be encrypted, while locations where physical parameters or geometric parameters are relatively flat can use a slightly sparse grid. In addition, in the initial stage of the simulation, such as Figure 4 As shown, the specific number of grids can be determined by combining the grid independence verification simultaneously.

[0071] Based on the above principles, this application first divides the fluid domain into multiple sub-areas, and adopts different grid shapes and grid numbers based on the geometric dimensions and medium flow characteristics of each sub-area, so as to maximize the reasonable allocation of computing resources, obtain reasonable calculation results, and promote the rapid development of control valve flow characteristics.

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

[0073] In some embodiments, for each sub-region, the grid size and grid shape are determined based on the severity of the change in the flow field parameters in the sub-region and its geometric shape, including:

[0074] B1, based on the severity of the change in flow field parameters in each sub-area, the size of the grid is reduced in order from small to large;

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

[0076] B3, for the grids where the drastic degree of flow field parameter change is less than the second preset value, and the sub-regions where the grid lines are inconsistent with the medium flow direction, a tetrahedral grid is used; the second preset value is less than the first preset value;

[0077] B4, hexahedral mesh is used for the inlet and outlet pipe areas;

[0078] B5, using tetrahedral mesh for the intersection area of ​​inlet and outlet pipes;

[0079] B6, a pyramidal pentahedral mesh is used for the sub-region where the mesh transitions from hexahedral to tetrahedral.

[0080] In this step, the grid generation technology is a very critical step. The quality of the grid has a direct impact on the calculation accuracy and efficiency. For the calculation of complex problems, grid division is extremely time-consuming and error-prone, and may even take up 80% of the total time of the entire calculation process. Therefore, it is necessary to reasonably design and generate the grid to ensure the calculation accuracy requirements while using the computing power in the key positions.

[0081] Based on the above reasons, step B1 can save computing power by using the densest grid for the sub-region where the flow field parameters change more dramatically, and the sparsest grid for the sub-region where the flow field parameters change most slowly.

[0082] In addition, different mesh shapes also directly affect the calculation results. Figure 5 The commonly used grid shapes are shown in FIG. 1 , and different grid shapes have different effects on computing power. This embodiment can effectively reduce the dissipation in the computing process and improve the adaptability of the model to complex geometry through the grid division form of steps B2 to B6.

[0083] In addition, for areas where the difference in geometric dimensions between two continuous sub-areas exceeds a preset order of magnitude, discontinuous grids can also be used. Each sub-area generates a grid according to its own scale, and then the two areas are connected with a discontinuous grid interface. The physical quantities will be interpolated on this interface during calculation. Figure 6 As shown in the figure, for a certain opening condition of a certain specification of the regulating valve, the throttling surface width d1 is only at the level of 10e-2mm, while the downstream d2 size is at the level of 10e2mm. From d1 to d2, in the area of ​​height h of about 1mm, the geometric size differs by 4 orders of magnitude. For such problems with large local size spans, discontinuous grids can be used, starting with local densification, and increasing the size of the grid division outward according to a suitable gradient. The grid should be as slow as possible from dense to sparse to ensure that the flow field details can be fully and correctly captured, such as pressure gradient, velocity gradient, and the integrity of the velocity direction change trend, etc. Otherwise, the calculation is very likely to diverge.

[0084] It should also be noted that for the mesh of the boundary layer, due to the reduction in velocity caused by the throttling surface, the Reynolds number Re of the medium flow state will usually decrease sharply here, closer to the laminar state, and the wall effect caused by the fluid viscosity will also be amplified accordingly. Therefore, in the direction away from the wall, the density of the mesh is reduced in sequence, and the meshes before and after optimization are as follows: Figure 7 and Figure 8 As shown in the figure, the speed cloud diagrams before and after optimization are as follows: Fig. 9 and Fig.10 As shown in the figure, it can be seen that the flow field velocity obtained by using the grid division method of the present application is more accurate.

[0085] In addition, in step 106, the three-dimensional model of the fluid domain after meshing is simulated and calculated based on the CFD simulation technology to obtain the simulation value of the flow characteristic of the regulating valve under the theoretical profile and the opening, including:

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

[0087] S2, determining the initial value of the current physical parameter of the current calculation round;

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

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

[0090] S5, determining whether the first absolute residual is not greater than the first residual threshold; if so, executing S6; if not, taking the sum of the new physical parameter value and the set step length as the initial value of the next calculation round, and returning to execute S3 to S5, until the calculated first absolute residual is not greater than the first residual threshold, and executing S6;

[0091] S6, using the new physical parameter value as a simulation value of the flow characteristic of the regulating valve under the theoretical profile and the opening.

[0092] In this embodiment, by analyzing the dimensionless parameter Re of the fluid medium flow in the regulating valve, it is determined whether the working condition that needs CFD calculation is turbulent or laminar, and the corresponding flow state calculation model, wall function model, etc. are input. The physical property parameters of the fluid medium include density, viscosity, temperature, etc. The boundary conditions determine whether the calculation results are reasonable and correct, and analyze the physical problems of the working condition. The inlet boundary conditions include: at least one of the inlet pressure, inlet velocity and inlet mass flow rate; the outlet boundary conditions include: at least one of the outlet pressure, outlet velocity, outlet mass flow rate and free outlet. The wall conditions include moving without slip and slip. When uncertain, the calculation results of several groups of schemes can be compared to determine the most reasonable scheme.

[0093] In addition, for each opening, steps S1 to S6 can be used until the calculation converges to obtain the simulation results of the flow characteristics under the opening. The calculation formula for the first absolute residual is |Q1-Q0|, where Q0 is the initial value of the physical parameter at the beginning of this round of calculation, and Q1 is the new physical parameter value obtained in this round of calculation. When the absolute residual is less than the set first residual threshold, it means that the calculation has converged. The first residual threshold can be 1e-3. Of course, the relative residual can also be used as a criterion for convergence. The calculation formula for 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, speed, etc.) is very stable, it can also be considered to have converged, such as Figure 11-14 As shown, the obtained residual curve, outlet mass flow curve, inlet and outlet mass flow curves and outlet volume flow curve can be used as the judgment criteria for convergence.

[0094] It should also be noted that the simulation results output by CFD calculation 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 import mass flow, average export mass flow, etc.

[0098] The schematic diagrams of velocity field distribution cloud map, streamline map and pressure field distribution cloud map are as follows: Figure 15-17 shown.

[0099] Finally, for step 108, by sorting and analyzing the simulation results at each opening, data can generally be extracted through color cloud maps, contour maps, streamline maps and numerical reports of specific physical quantities, such as inlet and outlet mass flow rates, average velocity, inlet and outlet pressures, etc. The extracted data can show whether the global flow state is reasonable, whether there is separation in certain areas, and whether the key flow characteristics are accurately calculated. When performing specific analysis, it is necessary to be based on the basic knowledge of fluid mechanics, and specific physical quantities also require quantitative analysis. The calculation model of the present invention can extract parameters such as outlet mass flow rate and inlet and outlet average pressure, summarize and draw the flow characteristic curve of the regulating valve, and compare it with the theoretical value. When the second absolute residual at all openings is less than the second residual threshold (such as ±5%), the corrected theoretical valve core profile can be used as the corrected valve core profile.

[0100] It should be noted that after a certain simulation calculation, if the simulation results at an opening of 40% to 100% meet the deviation requirements from the theoretical simulation results. Then the valve core profile can be corrected based on the simulation results of a small opening of 30%, and the theoretical calculation and simulation calculation of the 0-30% opening are re-performed for the corrected valve core until each opening meets the requirements. This is because the valve core profile has little effect on the total throttling surface of the fluid domain. After adjusting the valve core profile, the effect on the flow characteristics at a large opening is small, so it can be ignored. This optimization method can greatly improve the correction speed while ensuring the calculation accuracy. Of course, the user can also recalculate all openings, and this application does not make specific restrictions.

[0101] In order to verify the effect of the method of the present application, the inventors compared the deviations of the calculation results of the method of the present application and the calculation results of the existing method with the theoretical results at various openings of the regulating valve (0-100%). Fig.18 As shown in the figure, it can be seen that the deviation between the calculation results of the existing method and the theoretical results is 5% to 28%, while the deviation between the calculation results of the method of the present application and the theoretical results is ±5%.

[0102] It can be seen that the method of the present application can significantly improve the calculation accuracy of the valve core profile.

[0103] It should also be noted that after the theoretical profile is corrected through CFD simulation, its flow characteristics can also be verified through experiments. If the test results do not meet the requirements, the method of this application is used to re-calculate the theory and CFD calculations to obtain a new valve core profile until the test results meet the requirements and the final valve core profile is obtained. In this way, a valve core profile with more accurate control accuracy can be obtained, the design goal of the flow characteristics of the regulating valve can be achieved, the qualified rate of prototype verification can be improved, and the development cost can be reduced.

[0104] like Figure 2 , Figure 3 As shown, an embodiment of the present invention provides a device for determining the valve core profile of a regulating valve. The device embodiment can be implemented by software, or by hardware or a combination of software and hardware. From the hardware level, Figure 2 As shown, it is a hardware architecture diagram of a computing device where a device for determining a valve core profile of a regulating valve provided by an embodiment of the present invention is located, except Figure 2 In addition to the processor, memory, network interface, and non-volatile memory shown in the figure, the computing device in which the device is located in the embodiment may also generally include other hardware, such as a forwarding chip responsible for processing messages, etc. Taking software implementation as an example, Figure 3 As shown, as a device in a logical sense, the CPU of the computing device in which it is located reads the corresponding computer program in the non-volatile memory into the internal memory and runs it.

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

[0106] The determination unit 300 is used to determine the main parameters of the valve core calculation of the regulating valve based on the application scenario of the regulating valve; the main parameters include: flow characteristic type, caliber, flow state type, calculation boundary and boundary layer processing method;

[0107] The calculation unit 302 is used to select a theoretical calculation mathematical model for valve core design based on the type of flow characteristic, and calculate the theoretical profile of the valve core and the theoretical value of the flow characteristic of the regulating valve at different openings based on the mathematical model and main parameters;

[0108] A construction unit 304 is used to construct a three-dimensional model of the regulating valve at different openings based on the diameter of the regulating valve and the theoretical profile of the valve core;

[0109] The simulation unit 306 is used to perform the following steps for each three-dimensional model of the regulating valve at each opening: extracting a three-dimensional model of the fluid domain at the opening from the three-dimensional model of the regulating valve, and meshing the three-dimensional model of the fluid domain; performing simulation calculation on the meshed three-dimensional model of the fluid domain based on the CFD simulation technology to obtain a simulation value of the flow characteristic of the regulating valve at the theoretical profile and the opening;

[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, until a corrected valve core profile is obtained.

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

[0112] The calculation boundary includes the inlet, outlet and wall of the medium.

[0113] In some embodiments, meshing the fluid domain three-dimensional model includes:

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

[0115] For each sub-region, the grid size and grid shape are determined based on the severity of the change of flow field parameters in the sub-region and its geometric shape;

[0116] The sub-region is meshed based on the mesh size and mesh shape.

[0117] In some embodiments, for each sub-region, the grid size and grid shape are determined based on the severity of the change in the flow field parameters in the sub-region and its geometric shape, including:

[0118] Based on the severity of the change in flow field parameters in each sub-area, the size of the grid is reduced in order from small to large;

[0119] For the sub-regions where the drastic degree of change of the flow field parameters exceeds the first preset value, and the sub-regions where the grid lines are consistent with the medium flow direction, a quadrilateral grid or a hexahedral grid is used;

[0120] For the grids whose flow field parameter changes are less than the second preset value and the sub-regions whose grid lines are inconsistent with the medium flow direction, a tetrahedral grid is used; the second preset value is less than the first preset value;

[0121] For the inlet and outlet pipe regions, hexahedral meshes are used;

[0122] For the intersection area of ​​the inlet and outlet pipes, a tetrahedral mesh is used;

[0123] For the sub-region where the mesh transitions from hexahedral to tetrahedral, a pyramid-shaped pentahedral mesh is used.

[0124] In some embodiments, the fluid domain range at each opening is determined by:

[0125] The fluid domain has clear boundaries, and each boundary has physical parameters that meet the requirements; the physical parameters include mass flow, pressure and velocity;

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

[0127] In some implementations, a simulation calculation is performed on the meshed three-dimensional model of the fluid domain based on CFD simulation technology to obtain a simulation value of the flow characteristic of the regulating valve under the theoretical profile and the opening, including:

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

[0129] S2, determining the initial value of the current physical parameter of the current calculation round;

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

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

[0132] S5, determining whether the first absolute residual is not greater than the first residual threshold; if so, executing S6; if not, taking the sum of the new physical parameter value and the set step length as the initial value of the next calculation round, and returning to execute S3 to S5, until the calculated first absolute residual is not greater than the first residual threshold, and executing S6;

[0133] S6, using the new physical parameter value as a simulation value of the flow characteristic of the regulating valve under the theoretical profile and the opening.

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

[0135] S7, respectively calculating the second absolute residual between the theoretical value and the simulation value at each opening, and determining whether there is at least one second absolute residual greater than the second residual threshold; if so, executing S8, if not, executing S9;

[0136] S8, select the largest opening from the openings corresponding to the second absolute residual greater than the second residual threshold; based on the simulation result corresponding to the largest opening, re-use the mathematical model to calculate the new theoretical profile of the valve core and the new theoretical result corresponding to the new theoretical profile; for the largest opening and other openings less than the largest opening, re-execute: extract the three-dimensional model of the fluid domain under the opening from the three-dimensional model of the regulating valve, and mesh the three-dimensional model of the fluid domain; re-simulate and calculate the meshed three-dimensional model of the fluid domain based on the CFD simulation technology to obtain a new simulation value of the flow characteristic of the regulating valve under the new theoretical profile and the opening; for the new theoretical value and the new simulation value, re-execute S7 and S8 until the second absolute residual corresponding to each opening is not greater than the second residual threshold, and execute S9;

[0137] S9, taking 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 embodiment is only illustrated by the division of the above functional modules. In actual 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 embodiment and the embodiment of the method for determining the valve core profile of the regulating valve belong to the same concept. The specific implementation process is detailed in the method embodiment and will not be repeated here.

[0139] The embodiment of the present application also provides a computer device, please refer to Figure 3 The computer device includes a processor and a memory, in which at least one instruction, at least one program, a code set or an instruction set is stored, and the at least one instruction, at least one program, a code set or an 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-mentioned method embodiments.

[0140] An embodiment of the present application also provides a computer-readable storage medium, on which is stored at least one instruction, at least one program, code set or instruction set, and 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 a regulating valve provided in the above-mentioned method embodiments.

[0141] An embodiment of the present application also provides 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 the processor executes the computer program, so that the computer device executes the method for determining the valve core profile of a regulating valve described in any of the above embodiments.

[0142] For the convenience of description, the above system or device is described by dividing it into various modules or units according to its functions. Of course, when implementing the present application, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0143] It can be known from the description of the above implementation methods that those skilled in the art can clearly understand that the present application can be implemented by means of software plus a necessary general hardware platform. Based on such an understanding, the technical solution of the present application can be essentially or partly contributed to the prior art in the form of a software product, which can be stored in a storage medium such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in the various embodiments of the present application or certain parts of the embodiments.

[0144] Finally, it should be noted that, in this article, relational terms such as first, second, third and fourth are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0145] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A method for determining a valve core profile of a regulating valve, characterized in that: The method comprises: Based on the application scenario of the regulating valve, determine the main parameters for calculating the regulating valve core; the main parameters include: flow characteristic type, caliber, flow pattern type, calculation boundary and boundary layer processing method; Based on the type of flow characteristics, a theoretical calculation mathematical model for valve core design is selected, and based on the mathematical model and the main parameters, a theoretical profile of the valve core and theoretical values ​​of flow characteristics of the regulating valve at different openings are calculated; Based on the caliber of the regulating valve and the theoretical profile of the valve core, constructing a three-dimensional model of the regulating valve at different openings; For each three-dimensional model of the regulating valve at each opening, the following steps are performed: extracting a three-dimensional model of the fluid domain at the opening from the three-dimensional model of the regulating valve, and meshing the three-dimensional model of the fluid domain; performing simulation calculation on the meshed three-dimensional model of the fluid domain based on CFD simulation technology to obtain a simulation value of the flow characteristic of the regulating valve at the theoretical profile and the opening; Based on the difference between the theoretical value and the simulation value at each opening, the theoretical profile of the valve core is corrected until a corrected valve core profile is obtained.

2. The method according to claim 1, characterized in that The caliber is determined based on the pipeline resistance of the regulating valve and the maximum flow rate that needs to be controlled; The calculation boundary includes the inlet, outlet and wall of the medium.

3. The method according to claim 1, characterized in that Meshing of the 3D model of the fluid domain, including: Based on the flow direction and flow characteristics of the medium in the fluid domain, the fluid domain is divided into a plurality of continuous sub-regions; the sub-regions at least include an inlet pipe region, an outlet pipe region, and an inlet and outlet pipe intersection region; For each of the sub-regions, the grid size and grid shape are determined based on the severity of the change in the flow field parameters in the sub-region and its geometric shape; The sub-region is meshed based on the mesh size and the mesh shape.

4. The method according to claim 3, characterized in that For each of the sub-regions, the grid size and grid shape are determined based on the severity of the change in the flow field parameters in the sub-region and its geometric shape, including: Based on the severity of the change in flow field parameters in each sub-area, the size of the grid is reduced in order from small to large; For the sub-regions where the drastic degree of change of the flow field parameters exceeds the first preset value, and the sub-regions where the grid lines are consistent with the medium flow direction, a quadrilateral grid or a hexahedral grid is used; For the grids whose flow field parameter variation is less than the second preset value and the sub-regions whose grid lines are inconsistent with the medium flow direction, a tetrahedral grid is used; the second preset value is less than the first preset value; For the inlet pipe area and the outlet pipe area, a hexahedral grid is used; For the intersection area of ​​the inlet and outlet pipes, a tetrahedral grid is used; For the sub-region where the mesh transitions from hexahedral to tetrahedral, a pyramid-shaped pentahedral mesh is used.

5. The method according to claim 3, characterized in that: The fluid domain range at each opening is determined as follows: The fluid domain has clear boundaries, and each boundary has physical parameters that meet the requirements; the physical parameters include mass flow, pressure and velocity; There is no backflow at the flow field outlet of the fluid domain and the fluid domain meets the boundary stability requirements.

6. The method according to claim 1, characterized in that The CFD simulation technology is used to simulate and calculate the three-dimensional model of the fluid domain after meshing to obtain the simulation value of the flow characteristic of the regulating valve under the theoretical profile and the opening, including: S1, determining the input parameters of the CFD simulation calculation; the input parameters include the time state of the three-dimensional model of the fluid domain, the type of flow state, the fluid medium parameters, the physical parameters of the flow field that need to be calculated and monitored, the inlet boundary conditions and the outlet boundary conditions; S2, determining the initial value of the current physical parameter of the current calculation round; S3, based on the input parameter and the initial value of the current physical parameter, iteratively calculate each grid in the three-dimensional model of the fluid domain in turn according to the NS equation along the flow direction of the medium until the last grid is traversed to obtain a new physical parameter value of the current calculation round; S4, calculating the first absolute residual between the new physical parameter value and the current initial value of the physical parameter; S5, determining whether the first absolute residual is not greater than the first residual threshold; if so, executing S6; if not, taking the sum of the new physical parameter value and the set step length as the initial value of the next calculation round, and returning to execute S3 to S5, until the calculated first absolute residual is not greater than the first residual threshold, and executing S6; S6, using the new physical parameter value as a simulation value of the flow characteristic of the regulating valve under the theoretical profile and the opening.

7. The method according to claim 6, characterized in that The method of correcting the theoretical profile of the valve core based on the difference between the theoretical value and the simulation value at each opening until a corrected valve core profile is obtained includes: S7, respectively calculating the second absolute residual between the theoretical value and the simulation value at each opening, and determining whether there is at least one second absolute residual greater than a second residual threshold; if so, executing S8; if not, executing S9; S8, selecting the maximum opening from the openings corresponding to the second absolute residual being greater than the second residual threshold; based on the simulation result corresponding to the maximum opening, re-using the mathematical model to calculate the new theoretical profile of the valve core and the new theoretical result corresponding to the new theoretical profile; for the maximum opening and other openings less than the maximum opening, re-execute: extracting the three-dimensional model of the fluid domain under the opening from the three-dimensional model of the regulating valve, and meshing the three-dimensional model of the fluid domain; re-simulating and calculating the meshed three-dimensional model of the fluid domain based on the CFD simulation technology to obtain a new simulation value of the flow characteristic of the regulating valve under the new theoretical profile and the opening; re-execute S7 and S8 for the new theoretical value and the new simulation value until the second absolute residual corresponding to each opening is not greater than the second residual threshold, and execute S9; S9, taking the final theoretical profile of the valve core as the final profile of the valve core.

8. A device for determining a valve core profile of a regulating valve, characterized in that: The device comprises: A determination unit, used to determine the main parameters for calculating the valve core of the regulating valve based on the application scenario of the regulating valve; the main parameters include: flow characteristic type, caliber, flow state type, calculation boundary and boundary layer processing method; A calculation unit, used for selecting a theoretical calculation mathematical model for valve core design based on the type of flow characteristic, and calculating a theoretical profile of the valve core and theoretical values ​​of flow characteristics of the regulating valve at different openings based on the mathematical model and the main parameters; A construction unit, used to construct a three-dimensional model of the regulating valve at different openings based on the caliber of the regulating valve and the theoretical profile of the valve core; The simulation unit is used to perform, for each three-dimensional model of the regulating valve at each opening degree: extracting a three-dimensional model of the fluid domain at the opening degree from the three-dimensional model of the regulating valve, and meshing the three-dimensional model of the fluid domain; performing simulation calculation on the meshed three-dimensional model of the fluid domain based on CFD simulation technology to obtain a simulation value of the flow characteristic of the regulating valve at the theoretical profile and the opening degree; The correction unit 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, until a corrected valve core profile is obtained.

9. A computer device, characterized in that: The computer device includes 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 in the memory to implement the steps of any one of the methods described in claims 1-7.

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

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