A simulation analysis method and system for a special control valve for a hydraulic support

Abstract

The present application relates to the field of fluid transmission technology, and specifically to a simulation analysis method and system for a special control valve for a hydraulic support. The method comprises: dividing the control valve flow path into regions according to the valve port distribution of the special control valve for the hydraulic support; analyzing the distribution of the curl of the velocity vectors of all grid cells in each region and the pressure distribution at each time step to obtain the flow field change characteristic values ​​of each region; obtaining the flow field complexity of the flow path inside the control valve; obtaining the truncation error of each time step based on the pressure data of all grid cells in the control valve flow path at each time step; analyzing the difference between the flow field complexities at adjacent time steps, and combining the error threshold of the previous time step to obtain the error threshold of each time step; and adjusting the step size of the flow field solution for the simulation analysis of the special control valve for the hydraulic support. The present application aims to improve the simulation analysis effect of the flow characteristics of the fluid inside the control valve.

Description

Technical Field

[0001] The present application relates to the field of fluid transmission technology, and in particular to a simulation analysis method and system for a special control valve for a hydraulic support. Background Art

[0002] Hydraulic supports are essential equipment for high-yield, efficient, and modern coal mining. They primarily support the roof of fully mechanized mining faces and ensure operational space. The performance and accuracy of the hydraulic transmission and control systems of hydraulic supports directly impact the reliability and safety of the entire fully mechanized mining face. To ensure the safety of underground workers, the performance of key components of hydraulic supports must be accurately evaluated. Using software to simulate and analyze the flow field within hydraulic components enables efficient and accurate calculation of the velocity and pressure distribution of the flow field, thereby determining the flow characteristics of the fluid within the hydraulic component. This is a commonly used technical approach for evaluating the performance of hydraulic supports within the industry.

[0003] The control valve for hydraulic supports switches the fluid supply circuit by controlling the position of the control handle. The flow characteristics of the fluid within the control valve's internal flow path affect the performance of the control valve and the entire hydraulic support, making accurate performance evaluation of the control valve for hydraulic supports crucial. The structure of the control valve for hydraulic supports is complex, with complex boundaries such as sudden expansions, contractions, and curved flow paths. Fluid flow through these complex flow paths can generate vortices, secondary flows, wall detachment, and reattachment, resulting in rapid changes in the internal flow field.

[0004] The choice of flow field simulation step size significantly impacts truncation error and solution efficiency. Excessively large step sizes result in significant truncation errors and reduced flow field simulation accuracy; while too small a step size reduces solution efficiency due to the increased number of calculation steps. In the hydraulic support flow field simulation, using a fixed step size for flow field solution is unable to adapt to the rapid changes in the fluid flow field within the hydraulic support's control valve, resulting in poor simulation results of the fluid flow characteristics within the control valve, which in turn affects the performance evaluation of the hydraulic support's control valve. Summary of the Invention

[0005] In view of the above, it is necessary to provide a simulation analysis method and system for a special control valve for a hydraulic support to solve the above problems.

[0006] A first aspect of the present application provides a simulation analysis method for a hydraulic support dedicated control valve, the method comprising:

[0007] Obtain the flow field data distribution of velocity vector and pressure of fluid in different grid cells at each time step in the simulation analysis of the hydraulic support special control valve;

[0008] Based on the position of the control handle and the distribution of the valve ports of the hydraulic support control valve, the control valve flow channel is divided into regions. The distribution of the curl of the velocity vectors of all grid cells in each region at each time step and the pressure distribution are analyzed. The curl and pressure at a preset number of time steps are fitted to obtain the flow field variation characteristic values ​​of each region. The flow field complexity of the flow channel inside the control valve is obtained based on the difference distribution between the flow field variation characteristic values ​​of adjacent regions.

[0009] Based on the second-order difference distribution of the pressure data of all grid cells in the control valve flow channel at each time step, combined with the step size of the previous time step, the truncation error of each time step is obtained; the difference between the flow field complexity at each time step and the adjacent time step is analyzed, and combined with the error threshold at the previous time step, the error threshold of each time step is obtained;

[0010] Based on the numerical values ​​of the truncation error and the error threshold at each time step, the step size of the flow field solution for the simulation analysis of the hydraulic support control valve is adjusted.

[0011] Among them, the control valve flow path is determined by the valves distributed on both sides of the valve core.

[0012] The control valve flow channel is divided into regions as follows:

[0013] For any control valve flow channel, the control valve flow channel is divided into regions using the first valve port end face, the valve core end face close to the first valve port, the valve core end face close to the second valve port, and the second valve port end face as dividing interfaces.

[0014] The step of obtaining the flow field change characteristic value of each area is as follows:

[0015] Fit the average absolute value of curl and average pressure p of each region in the current time step and the previous preset number of time steps respectively to obtain the slope of the fitting line 、 ;

[0016] The characteristic value of the flow field change in each region at the current time step is recorded as F, and its formula is as follows: , where norm() represents the arctangent normalization function; exp[] represents the exponential function with a natural constant as the base.

[0017] The average absolute value of the curl is specifically the average value of the absolute values ​​of the velocity vectors of all grid cells in each region at the current time step; and the average pressure is specifically the average value of the pressures of all grid cells in each region at the current time step.

[0018] The flow field complexity of the internal flow channel of the control valve is obtained as follows:

[0019] Calculate the average value of the flow field change eigenvalues ​​of all regions at the current time step, and calculate the cumulative sum of the differences between the flow field transformation eigenvalues ​​of each region and its previous region; forwardly fuse the average value of the flow field change eigenvalues ​​with the cumulative sum as the flow field complexity of the internal flow channel of the control valve.

[0020] The specific process of obtaining the truncation error at each time step is as follows:

[0021] The average value of the second-order difference value of the pressure data of all grid cells in the control valve flow channel at each time step is obtained, and forward fused with the step size of the previous time step to obtain the truncation error of each time step.

[0022] The process of obtaining the error threshold for each time step is specifically as follows:

[0023] The difference between the flow field complexity of each time step and the previous time step is normalized and then added to the preset value; the addition result is forward fused with the error threshold of the previous time step to obtain the error threshold of each time step.

[0024] The process of adjusting the time step size of the flow field solution for the hydraulic support control valve simulation analysis based on the numerical values ​​of the truncation error and the error threshold at each time step is specifically as follows:

[0025] If the truncation error of the current time step does not exceed the error threshold, the next step length is adjusted to: ;

[0026] If the truncation error of the current time step is greater than the error threshold, the current time step is backed off and the step size of the current time step is adjusted to: ;

[0027] in, 、 Respectively represent the error threshold and truncation error at the i-th time step; Indicates the minimum time step size; max[] indicates the maximum value function; Indicates the maximum time step length; min[] indicates the minimum function; represents the step size of the i-th time step without backoff adjustment; represents the step size of the i-th time step after backoff adjustment; Indicates the step size of the i+1th time step without backoff adjustment.

[0028] In the second aspect, an embodiment of the present application also provides a simulation and analysis system for a hydraulic support-specific control valve, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor implements the steps of any one of the above-mentioned methods when executing the computer program.

[0029] This application has at least the following beneficial effects:

[0030] This application divides the flow channel of the control valve into regions based on the distribution of flow field data obtained by simulation, based on the position of the control handle and the valve port distribution of the hydraulic support special control valve, so as to facilitate the subsequent further analysis of the influence of the flow channel structure in the hydraulic support special control valve on the evolution of the fluid flow field; analyzes the distribution of the curl of the velocity vector of all grid cells in each region at each time step and the pressure distribution, and fits the curl and pressure at a preset number of time steps respectively to obtain the flow field change characteristic values ​​of each region, which can more accurately understand the flow characteristics in the hydraulic system and help improve the accuracy of the simulation model; according to the difference distribution between the flow field change characteristic values ​​of adjacent regions, the flow channel inside the control valve is obtained. Field complexity helps the simulation model to more realistically reflect the behavior of the hydraulic system; based on the second-order differential distribution of the pressure data of all grid cells in the control valve flow channel at each time step, combined with the step size of the previous time step, the truncation error of each time step is obtained, the difference between the flow field complexity at each time step and the adjacent time step is analyzed, and the error threshold at the previous time step is combined to obtain the error threshold of each time step. By combining the truncation error of each time step, the flow field complexity and the dynamic adjustment of the error threshold, the numerical simulation process can be optimized, and the calculation accuracy, stability and efficiency can be improved. The flow field evolution in the control valve is estimated in both time and space dimensions, and the accuracy of the subsequent adjustment of the simulation step size is improved. This application is based on the estimation of the fluid flow field evolution in the hydraulic support special control valve, and by adaptively adjusting the step size of the flow field simulation, while improving the accuracy of the simulation of the complex flow field in the control valve, it reduces the computational complexity of the flow field data under the stable state of the flow field, improves the simulation analysis effect of the fluid flow characteristics inside the control valve, and thus achieves an accurate performance evaluation of the hydraulic support special control valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A flowchart of a simulation analysis method for a special control valve for a hydraulic support provided in one embodiment of the present application;

[0032] Figure 2 A side view of a control valve provided in accordance with one embodiment of the present application;

[0033] Figure 3 A schematic diagram of the control valve segmentation provided for one embodiment of the present application. DETAILED DESCRIPTION

[0034] In the description of the embodiments of this application, words such as "exemplary," "or," and "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary," "or," and "for example" is intended to present the relevant concepts in a concrete manner.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the art of this application. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0036] It should also be noted that the terms "first" and "second" in this application and the accompanying drawings are used to distinguish similar objects, rather than to describe a specific order or sequence. The methods disclosed in the embodiments of this application or the methods shown in the flowcharts include one or more steps for implementing the methods. Without departing from the scope of protection of this application, the order of executing multiple steps can be interchanged with each other, and some steps can also be deleted.

[0037] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0038] The following describes in detail a simulation analysis method and system for a special control valve for a hydraulic support provided by the present application with reference to the accompanying drawings.

[0039] See also Figure 1 , which shows a flowchart of a simulation analysis method for a hydraulic support dedicated control valve provided by one embodiment of the present application, the method comprising the following steps:

[0040] The first step is to obtain the flow field data distribution of the velocity vector and pressure of the fluid in different grid units at each time step in the simulation analysis of the hydraulic support special control valve.

[0041] This application uses the computational fluid dynamics software FLUENT to perform numerical simulation and analysis on the hydraulic support special control valve, obtain the flow characteristics of the internal emulsion, and realize the performance evaluation of the control valve.

[0042] Taking into account the complex three-dimensional flow channel structure inside the hydraulic support special control valve, this application uses special CAD / CAE software, including but not limited to Pro / E, UG, IDEAS, CATIA, Solidworks, and PATRAN, based on the structural parameters of the control valve to establish the geometric model of the hydraulic support special control valve and obtain the control valve geometric model file.

[0043] The control valve geometry model file was then imported into the GAMBIT module of the FLUENT software. GAMBIT was then used to mesh the control valve geometry model. Tri-triangular meshing was used, and the Pave method was employed. An unstructured mesh was created using the specified mesh type, generating nodes and mesh elements.

[0044] The boundary conditions for the control valve simulation in this application do not consider gravity or the heat transfer of the emulsion within the flow channel. The walls are set to no-slip, adiabatic, and zero turbulent fluctuations. The simulated fluid is incompressible liquid water, the solver type is a standard two-equation model, and the convection term uses a first-order upwind scheme.

[0045] In this embodiment, the ambient pressure is set to one atmosphere, the inlet and outlet boundary conditions are set to pressure inlet 35MPa, pressure outlet 34Mpa, and nominal flow rate 200L / min. The implementer can adjust according to the specific performance evaluation requirements; the initial fixed time step size of the simulation is set to 10 -3 s, the initial fixed time step number is 100, and the minimum time step length is 10 -6 s, the maximum time step length is 1s, and the maximum number of time step iterations is 20.

[0046] At this point, the simulation model of the hydraulic support control valve is completed. The flow field inside the control valve is iteratively solved using FLUENT software to obtain the flow field data distribution of the velocity vector and pressure of the fluid in different grid cells at each time step.

[0047] The second step is to divide the flow field into regions according to the valve port distribution of the hydraulic support special control valve; analyze the distribution of the curl of the velocity vectors of all grid cells in each region at each time step and the pressure distribution, and fit the curl and pressure at a preset number of time steps respectively to obtain the flow field change characteristic values ​​of each region; according to the difference distribution between the flow field change characteristic values ​​of adjacent regions, the flow field complexity of the internal flow channel of the control valve is obtained.

[0048] The hydraulic support special control valve simulated and analyzed in this application has a total of 4 valve ports, distributed on both sides of the valve core. Figure 2 As shown in the figure, the valve port P, valve port A, valve port R, and valve port B. The control valve realizes the reversal of the liquid supply circuit by controlling the position of the control handle.

[0049] When the joystick is in the middle position, no fluid flows and no simulation analysis is required.

[0050] When the control handle is turned upward, fluid is supplied through the PA channel and returned through the RB channel. When the control handle is turned downward, fluid is supplied through the PB channel and returned through the RA channel. This application describes in detail the simulation and analysis process of the control valve fluid flow field, using the control valve flow path structure formed when the control handle is turned upward as an example. Valve ports P and R are located on the same side of the valve core, while valve ports A and B are located on the other side of the valve core.

[0051] It should be further explained that the flow path structure of the control valve when the control handle is turned to the downward position is symmetrical with the flow path structure of the control valve when the control handle is turned to the upward position. The simulation analysis process of the two is the same, and this application will not go into details.

[0052] In the first N initial fixed time steps, the application uses the initial fixed time step size to perform flow field simulation and solve, and obtain the fluid velocity vector and pressure of each grid unit in the PA channel and the RB channel, where the initial fixed time step size is 10 -3 s, and the initial fixed time step number N is 100.

[0053] The internal flow path structure of the control valve for hydraulic supports is relatively complex, with complex boundaries such as sudden expansion, contraction, and curved channels. When the fluid flows through these complex channels, it will produce flow phenomena such as vortices, secondary flow, wall detachment, and reattachment, resulting in rapid changes in the internal fluid flow field.

[0054] Taking into account the changes in the pipe diameter in the control valve flow channel, and the different energy losses caused by the flow resistance along the pipe diameter, the evolution of the fluid flow field in different pipe diameters is different.

[0055] Since the diameter of the control valve spool is larger than that of the other flow channels, in order to accurately obtain the intensity of the evolution of the fluid flow field in different diameter areas of the flow channel over time, when the control handle is turned to the upward position, the PA channel supplies liquid and the RB channel returns liquid, and the fluid flows from the P valve port to the B valve port. At this time, the PA channel is divided into the inlet area, the valve spool area and the outlet area in sequence with the P valve port end face, the valve spool end face in the PA channel close to P, the valve spool end face in the PA channel close to A, and the A valve port end face as the dividing interface. Since the flow channel structures of the PA channel and the RB channel are symmetrical to each other, the same method is used to divide the RB channel into the inlet area, the valve spool area and the outlet area in sequence. Among them, the schematic diagram of the control valve segmentation is shown as follows Figure 3 As shown, Figure 3It includes: P valve port end face 1; the end face 2 of the valve core in the PA channel close to P; the end face 3 of the valve core in the PA channel close to A; the A valve port end face 4; the R valve port end face 5; the end face 6 of the valve core in the RB channel close to R; the end face 7 of the valve core in the RB channel close to B; the B valve port end face 8; the inlet area 9 of the PA channel; the valve core area 10 of the PA channel; the outlet area 11 of the PA channel; the hydraulic execution structure 12 of the hydraulic support; the inlet area 13 of the RB channel; the valve core area 14 of the RB channel; and the outlet area 15 of the RB channel.

[0056] According to the order of the inlet area, valve core area, outlet area of ​​the PA channel, and the inlet area, valve core area, outlet area of ​​the RB channel, the six areas are numbered from 1 to 6 to obtain the serial number of each area; the implementer may choose other numbering methods.

[0057] The vortex motion of the fluid within the control valve, caused by the pressure differential, is a key factor influencing the evolution of the flow field. This vortex motion consumes flow energy, resulting in energy loss and affecting the switching performance of the control valve.

[0058] The curl of the velocity vector of each grid cell in the flow field is calculated, and the average of the absolute values ​​of the curl of all grid cells in the region at each time step is calculated. This is recorded as the average absolute value of the curl of the region, which is used to measure the intensity of the local rotation and circulation of the fluid in the flow field in the corresponding region.

[0059] At the same time, the average pressure of all grid cells in the region at each time step is calculated and recorded as the average pressure of the region.

[0060] To capture more details of the fluid vortex motion in the flow field and thereby improve the performance evaluation of the control valve, it is necessary to set a smaller flow field solution time step when strong vortex motion occurs in the region. Fluid vortex motion changes rapidly over time, and the circulation of vortices within the flow field directly affects the intensity of the flow field evolution. Therefore, the average absolute curl values ​​of the current time step and the N-1 time steps before it are arranged in chronological order into a sequence, recorded as the average absolute curl value sequence of the current time step, to represent the evolution trend of the flow field in the region.

[0061] Furthermore, the mean curl absolute value sequence is used as input, and the least squares fitting method is used to output its fitted line and slope. It should be understood that the larger the slope of the fitted line of the mean curl absolute value sequence, the greater the probability of intensified fluid vortex motion in the corresponding area, and therefore the greater the probability of violent flow field evolution.

[0062] Accordingly, based on the average pressure of the region at each time step, the average pressure sequence of the region at the current time step, as well as its fitted line and slope, are obtained. Since cavitation is more likely to occur in areas with lower pressure within the control valve flow channel, and cavitation within the flow field further exacerbates the evolution of the flow field, causing the average pressure within the flow field to further decrease, the lower the average pressure of the regional flow field, the more cavitation occurs within the flow channel, reflecting a greater degree of flow field evolution.

[0063] In addition, the larger the absolute value of the average curl obtained at the current time step, the more intense the fluid flow in the corresponding area; at the same time, the smaller the slope of the fitting straight line of its average pressure series, indicating that more cavitations have appeared during the evolution of the flow field and the greater the degree of change in the flow field, the smaller the flow field simulation solution time step needs to be set in the future to improve the evaluation performance of the control valve.

[0064] According to the distribution and changes of fluid velocity vector and pressure in the region, the characteristic value of flow field change in each region is calculated: ;in, 、 The slopes of the fitted lines for the region's average curl and average pressure, respectively; norm() represents the arctangent normalization function, whose normalized value range is (-1, 1) to control the calculation range of the flow field variation eigenvalue; exp() represents an exponential function with a natural constant as its base, whose purpose is to ensure that the calculated flow field variation eigenvalue is positive; curl represents the region's average curl absolute value at the current time step; p represents the region's average pressure at the current time step; and F represents the region's flow field variation eigenvalue, reflecting the degree of flow field variation in the region at the current calculation time step. A larger flow field variation eigenvalue indicates a greater degree of flow field variation in the corresponding region at that time step.

[0065] In addition to the impact of the internal flow field evolution trend in each area on the performance evaluation of the control valve, considering that the diameter of the valve core in the control valve is large and there are multiple sudden contraction and expansion parts at the connection with the rest of the flow channel, the flow velocity and direction of the fluid at the connection will undergo multiple changes, and the probability of a complex turbulent state is high.

[0066] When the fluid evolution trends in two adjacent areas differ too much, the probability of violent fluid diversion, collision, and momentum exchange between the two areas increases, and the complexity of the fluid flow in the flow field increases. Subsequently, it is necessary to set a smaller solution step size to obtain more detailed flow field evolution data and improve the evaluation performance of the control valve.

[0067] The flow field complexity of the control valve's internal flow passage is calculated based on the flow field variation eigenvalues ​​of different regions. The following steps are performed: the average of the flow field variation eigenvalues ​​for all regions at the current time step is calculated, and the difference between each region and the previous region's flow field transformation eigenvalue is calculated as the cumulative sum. The average of the flow field variation eigenvalues ​​and the cumulative sum are forward-fused to form the flow field complexity of the control valve's internal flow passage. In this embodiment, the difference in flow field transformation eigenvalues ​​between regions is calculated using the absolute value of the difference; forward fusion of multiple variables is performed using multiplication.

[0068] It should be understood that the average value of the flow field change characteristic values ​​of all regions at the current time step reflects the average degree of change in the flow field of the control valve; the absolute value of the difference between the flow field change characteristic values ​​between regions reflects the difference in the fluid evolution trends of the two regions. Since the first region does not exist in the previous region, the flow field change characteristic values ​​between the regions cannot be calculated, so they are not calculated; in addition, in the process of the fluid flowing from the PA channel back to the RB channel through the execution structure, the probability of flow field change in the last region of the former and the first region of the latter is greater because they are near the valve port. Therefore, the difference in the fluid evolution trends between the two is also used to characterize the complexity of their flow field changes.

[0069] The third step: Based on the second-order differential distribution of the pressure data of all grid cells in the control valve flow channel at each time step, combined with the step size of the previous time step, the truncation error of each time step is obtained; the difference between the flow field complexity at each time step and the adjacent time step is analyzed, and combined with the error threshold at the previous time step, the error threshold at each time step is obtained.

[0070] During the simulation analysis of a hydraulic support control valve, the choice of time-step compensation significantly impacts the accuracy and efficiency of the flow field data solution. When the flow field is highly complex, a smaller time-step size is used to improve the accuracy of the flow field data solution. Furthermore, when the fluid motion within the control valve is relatively small, a larger time-step size is used to minimize the impact on the simulation efficiency.

[0071] This application uses the pressure of the grid unit as a reference and obtains the average truncation error of the grid unit pressure through second-order accuracy approximation. The specific calculation method is: obtain the average value of the second-order difference value of the pressure data of all grid units in the control valve flow channel at each time step, and forward fuse it with the step size of the previous time step to obtain the truncation error of each time step.

[0072] In this embodiment, the formula for truncation error is: ;in, represents the step size of the i-1th time step; represents the average value of the second-order difference of pressure of all grid cells in the control valve flow channel at the i-th time step; Represents the truncation error of the i-th time step, which serves as an estimate of the solution accuracy of the current time step. The larger the truncation error, the lower the solution accuracy of the corresponding time step.

[0073] When the flow field within the control valve flow channel is complex, higher solution accuracy is required to improve the simulation analysis capabilities of the flow field data and enhance the evaluation of the control valve. Therefore, based on the flow field complexity at the current time step, the error threshold is calculated: the difference between the flow field complexity of each time step and the previous time step is normalized and added to the preset value; the result of the addition is forward-fused with the error threshold of the previous time step to obtain the error threshold for each time step.

[0074] In this application, the difference between the flow field complexities is calculated by difference; the forward fusion of multiple variables is calculated by multiplication, and the preset value is 1. The specific formula is as follows: ;in, 、 They represent the flow field complexity at the i-1th time step and the i-th time step respectively; norm() represents the arc tangent normalization, and its normalized value range is (-1,1). The purpose is to control the calculation range of the error threshold. The addition of 1 is to ensure that the error threshold of the next time step can become larger or smaller than that of this time step; and They represent the error thresholds at the i-1th and i-th time steps respectively. In this embodiment, the initial error threshold is set to 0.01.

[0075] It should be understood that when the flow field changes in the control valve flow channel become more complex, the flow field complexity increases, the error threshold decreases, and a smaller solution step size is set subsequently to ensure the accuracy of the flow field solution; when the complexity of the flow field changes in the control valve flow channel gradually decreases, the flow field complexity decreases, the error threshold increases, and a larger solution step size is set subsequently to ensure the efficiency of the flow field solution.

[0076] The fourth step: Based on the numerical values ​​of the truncation error and the error threshold at each time step, adjust the step size of the flow field solution for the hydraulic support control valve simulation analysis.

[0077] In this application, the specific adjustment method of the step size when solving the flow field of the hydraulic support special control valve simulation analysis is as follows:

[0078] If the truncation error of the current time step does not exceed its error threshold, the next step length is adjusted to: ;in, 、 Respectively represent the error threshold and truncation error at the i-th time step; Indicates the maximum time step length. In this embodiment, the value is 1. Its purpose is to prevent the step length of the next solution time step from being too large, which affects the simulation solution accuracy; min[] indicates the minimum value function; 、 They represent the step sizes of the i-th time step and the i+1-th time step without backoff adjustment, respectively.

[0079] If the truncation error of the current time step is greater than its error threshold, then the current time step needs to be backed off and the step size of the current time step is adjusted to: ;in, 、 Respectively represent the error threshold and truncation error at the i-th time step; Indicates the minimum time step length, which is 10 in this embodiment -6 , its purpose is to prevent the time step length of the backstep solution from being too small, which affects the simulation solution efficiency; max[] represents the maximum value function; represents the step size of the i-th time step without backoff adjustment; Represents the step size of the i-th time step after backoff adjustment.

[0080] The above method is used to adjust the simulation solution time step of the control valve flow field in real time, complete the simulation analysis of the hydraulic support special control valve, and realize accurate performance evaluation of the hydraulic support special control valve.

[0081] Based on the same inventive concept as the above-mentioned method, an embodiment of the present application also provides a simulation and analysis system for a hydraulic support-specific control valve, comprising a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, the steps of any one of the above-mentioned simulation and analysis methods for a hydraulic support-specific control valve are implemented.

[0082] In summary, this application divides the control valve flow channel into regions based on the flow field data distribution obtained by simulation, based on the position of the control handle and the valve port distribution of the hydraulic support special control valve, so as to facilitate the subsequent further analysis of the influence of the flow channel structure in the hydraulic support special control valve on the evolution of the fluid flow field; analyzes the distribution of the curl and pressure of the velocity vectors of all grid cells in each region at each time step, and fits the curl and pressure at a preset number of time steps respectively to obtain the flow field change characteristic values ​​of each region, which can more accurately understand the flow characteristics in the hydraulic system and help improve the accuracy of the simulation model; according to the difference distribution between the flow field change characteristic values ​​of adjacent regions, the flow inside the control valve is obtained. The complexity of the flow field in the channel helps the simulation model to more realistically reflect the behavior of the hydraulic system; based on the second-order differential distribution of the pressure data of all grid cells in the control valve flow channel at each time step, combined with the step size of the previous time step, the truncation error of each time step is obtained, the difference between the flow field complexity at each time step and the adjacent time step is analyzed, and the error threshold at the previous time step is combined to obtain the error threshold of each time step. By combining the truncation error, flow field complexity and dynamic adjustment of the error threshold at each time step, the numerical simulation process can be optimized, and the calculation accuracy, stability and efficiency can be improved. The flow field evolution in the control valve is estimated in both time and space dimensions, and the accuracy of subsequent adjustment of the simulation step size is improved. This application is based on the estimation of the fluid flow field evolution in the hydraulic support special control valve, and by adaptively adjusting the step size of the flow field simulation, while improving the accuracy of the simulation of the complex flow field in the control valve, it reduces the computational complexity of the flow field data under the stable state of the flow field, improves the simulation analysis effect of the fluid flow characteristics inside the control valve, and thus achieves accurate performance evaluation of the hydraulic support special control valve.

[0083] The flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the systems, methods and computer program products according to the embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and the part of the module, program segment or code contains one or more executable instructions for realizing the specified logical function. In some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. In the description corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different boxes can also occur in an order different from that disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. Each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified function or action, or may be implemented by a combination of dedicated hardware and computer instructions.

[0084] It is obvious to those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and that the present application can be implemented in other specific forms without departing from the basic features of the present application. Therefore, from any point of view, the above embodiments of the present application should be regarded as exemplary and non-restrictive; modifications to the technical solutions described in the above embodiments, or equivalent replacement of some of the technical features therein, do not deviate from the essence of the corresponding technical solutions within the scope of the technical solutions of the embodiments of the present application, and should be included in the scope of protection of the present application.

Claims

1. A simulation analysis method for a special control valve for a hydraulic support, characterized in that: The method comprises the following steps: Obtain the flow field data distribution of velocity vector and pressure of fluid in different grid cells at each time step in the simulation analysis of the hydraulic support special control valve; Based on the position of the control handle and the distribution of the valve ports of the hydraulic support control valve, the control valve flow channel is divided into regions. The distribution of the curl of the velocity vectors of all grid cells in each region at each time step and the pressure distribution are analyzed. The curl and pressure at a preset number of time steps are fitted to obtain the flow field variation characteristic values ​​of each region. The flow field complexity of the flow channel inside the control valve is obtained based on the difference distribution between the flow field variation characteristic values ​​of adjacent regions. Based on the second-order difference distribution of the pressure data of all grid cells in the control valve flow channel at each time step, combined with the step size of the previous time step, the truncation error of each time step is obtained; the difference between the flow field complexity at each time step and the adjacent time step is analyzed, and combined with the error threshold at the previous time step, the error threshold of each time step is obtained; Based on the numerical values ​​of the truncation error and the error threshold at each time step, the step size of the flow field solution for the hydraulic support control valve simulation analysis is adjusted; The steps of obtaining the flow field change characteristic values ​​of each region are: Fit the average absolute value of curl and average pressure p of each region in the current time step and the previous preset number of time steps respectively to obtain the slope of the fitting line 、 ; The characteristic value of the flow field change in each region at the current time step is recorded as F, and its formula is as follows: , where norm() represents the arctangent normalization function; exp[] represents the exponential function with a natural constant as the base; The average absolute value of the curl is specifically the average value of the absolute value of the velocity vectors of all grid cells in each area at the current time step; the average pressure is specifically the average value of the pressure of all grid cells in each area at the current time step; The flow field complexity of the internal flow channel of the control valve is obtained as follows: Calculate the average value of the flow field change eigenvalues ​​of all regions at the current time step, and calculate the cumulative sum of the differences between the flow field transformation eigenvalues ​​of each region and its previous region; forwardly fuse the average value of the flow field change eigenvalues ​​with the cumulative sum as the flow field complexity of the internal flow channel of the control valve.

2. The simulation analysis method for a special control valve for a hydraulic support according to claim 1, characterized in that: The flow path of the control valve is determined by the valves distributed on both sides of the valve core.

3. The simulation analysis method for a special control valve for a hydraulic support according to claim 2, characterized in that: The control valve flow channel is divided into regions as follows: For any control valve flow channel, the control valve flow channel is divided into regions using the first valve port end face, the valve core end face close to the first valve port, the valve core end face close to the second valve port, and the second valve port end face as dividing interfaces.

4. The simulation analysis method for a special control valve for a hydraulic support according to claim 1, characterized in that: The specific process of obtaining the truncation error of each time step is: The average value of the second-order difference value of the pressure data of all grid cells in the control valve flow channel at each time step is obtained, and forward fused with the step size of the previous time step to obtain the truncation error of each time step.

5. The simulation analysis method for a special control valve for a hydraulic support according to claim 1, characterized in that: The process of obtaining the error threshold for each time step is specifically as follows: The difference between the flow field complexity of each time step and the previous time step is normalized and then added to the preset value; the addition result is forward fused with the error threshold of the previous time step to obtain the error threshold of each time step.

6. The simulation analysis method for a special control valve for a hydraulic support according to claim 1, characterized in that: The process of adjusting the time step length of the flow field solution for the hydraulic support control valve simulation analysis based on the numerical values ​​of the truncation error and the error threshold at each time step is specifically as follows: If the truncation error of the current time step does not exceed the error threshold, the next step length is adjusted to: ； If the truncation error of the current time step is greater than the error threshold, the current time step is backed off and the step size of the current time step is adjusted to: ; in, 、 Respectively represent the error threshold and truncation error at the i-th time step; Indicates the minimum time step size; max[] indicates the maximum value function; Indicates the maximum time step length; min[] indicates the minimum function; represents the step size of the i-th time step without backoff adjustment; represents the step size of the i-th time step after backoff adjustment; Indicates the step size of the i+1th time step without backoff adjustment.

7. A simulation analysis system for a special control valve for a hydraulic support, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

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