Numerical simulation method for breathing hemisphere of driver of coal mining machine on fully mechanized coal mining face

Abstract

The invention discloses a numerical simulation method for a breathing hemisphere of a driver of a coal mining machine on a fully mechanized coal mining face. The numerical simulation method comprises the following steps: S1, establishing a geometric model of a construction site; s2, taking air flow as a continuous phase, and simulating a fully mechanized coal mining face fluid movement track; s3, the dust particles are regarded as discrete phases, and the fog dust diffusion process of the fully mechanized coal mining face is simulated; and S4, analyzing data and adjusting parameters. Multi-field coupling simulation of an underground air flow field, a dust field and the like can be realized, and spatial three-dimensional measurement and analysis of the dust field under influence factors of different air flow sizes, dust migration positions and the like are facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of underground coal mine fluid mechanics, and particularly relates to a numerical simulation method for the breathing hemisphere of shearer drivers in fully mechanized coal mining faces. Background Art

[0002] The fully mechanized coal mining face is one of the important sources of coal dust in coal mines. With the improvement of the mechanization and automation levels of coal mines and the increase in the mining degree, the dust pollution in the mine working places and the occupational health risks of miners have been exacerbated. During the actual mining process, a large amount of coal dust is generated during operations such as coal mining, transportation, and blasting. In such an environment, workers face a huge risk of pneumoconiosis. The harm of pneumoconiosis lies in its incurable nature. Patients have inhaled a large amount of dust in the dust working environment for a long time, and the dust accumulates in the lungs, resulting in the formation of local pulmonary fibrosis accompanied by nodular changes in the lungs. These pathological changes are irreversible. After the appearance of pulmonary fibrosis, the dust remaining in the lung tissue can still continue to act on macrophages. Even if the patient leaves the dust environment, the fibrosis will still continue to develop.

[0003] Currently, the existing related numerical simulation studies generally focus on the distribution and pollution of dust with the airflow during coal mining operations. Compared with the dust simulation results in fully mechanized coal mining faces, the research on the dust migration and diffusion law of shearer drivers is relatively lacking. Summary of the Invention

[0004] The present invention aims to solve the technical problems existing in the prior art, and particularly innovatively proposes a numerical simulation method for the breathing hemisphere of shearer drivers in fully mechanized coal mining faces, which can realize the multi-field coupling simulation of the underground airflow field, dust field, etc., and is convenient for the three-dimensional measurement and analysis of the dust field under influencing factors such as different airflow magnitudes and dust migration positions.

[0005] To achieve the above object, the present invention provides a numerical simulation method for the breathing hemisphere of shearer drivers in fully mechanized coal mining faces, including the following steps:

[0006] S1: Establish a geometric model of the construction site;

[0007] S1-1: Draw the geometric model; use Solidworks drawing software to establish an equi-proportioned geometric model of the fully mechanized coal mining face. This model is drawn according to requirements, and the geometric model consists of the working space of the working face, hydraulic supports, shearers, and scraper conveyors;

[0008] S1-2: In the large environment of the fully mechanized coal mining face, establish a driver breathing hemisphere model in the working area of the shearer driver; the breathing hemisphere is a hemispherical range with the mouth and nose of the shearer driver as the center of the sphere and in the front side of the face, representing the inhalable dust within the driver's breathing range;

[0009] S1-3: Determine the grid scheme for simulation;

[0010] S2: Treat the air current as a continuous phase and simulate the fluid movement trajectory of the fully mechanized coal mining face;

[0011] S3: Treat the dust particles as a discrete phase and simulate the fog dust diffusion process of the fully mechanized coal mining face;

[0012] S4: Analyze data and adjust parameters.

[0013] In the above solution: In steps S1-2, the sphere radius range of the respiratory hemisphere described is 0.4 m to 0.9 m, and the length, width, and height of the working space described in step S1-1 are respectively: 120 m×10 m×6.8 m.

[0014] In the above solution: Step S1-3 further includes the following steps:

[0015] S1-3-1: Conduct mesh division in the overall environment of the fully mechanized coal mining face and inside the respiratory hemisphere respectively, and formulate multiple mesh schemes; Adopt the polyhedra type mesh, optimize the poor-quality local meshes by eliminating the fragmented parts, and add multiple boundary layers;

[0016] Import the file of the geometric model into Mesh, use the tetrahedral mesh for mesh division through the curvature size of the mesh and the minimum size between adjacent meshes, and at the same time set mesh schemes with a variety of different mesh sizes to conduct mesh independence tests to ensure that the best mesh scheme is adopted during calculation;

[0017] S1-3-2: Select measurement points, and use the data of the measurement points as the verification parameters for mesh independence tests;

[0018] Select multiple measurement points at equal intervals at the breathing zone height in the sidewalk area of the working face to obtain the air current velocity, and use the air current velocity as the verification parameter for mesh independence tests;

[0019] S1-3-3: Compare the four mesh schemes according to the data of the measurement points, and adopt the mesh division scheme when the calculation results no longer change as the final mesh scheme;

[0020] S1-3-4: Import the final mesh scheme into Fluent, first adjust the scale to ensure that the size of the physical model is consistent with the actual size, and check the mesh quality.

[0021] In the above solution: Step S2 further includes the following steps:

[0022] S2-1: Open the steady-state environment in the fluid simulation software and enable the turbulence model; Among them, the fluid simulation software is Fluent;

[0023] S2-2: Set the initial conditions of the air current;

[0024] S2-3: Simulate the air flow state. After the simulation is completed, export the simulation data of the air flow field and the corresponding files.

[0025] S2-4: Import the simulation data of the air flow field and the corresponding files into the fluid simulation software again, convert the steady-state environment into a transient environment, and set the gravitational acceleration according to the model direction.

[0026] In the above solution: Step S2-2 further includes the following steps:

[0027] S2-2-1: Select the Pressure-Based Solver and set it for transient simulation.

[0028] S2-2-2: Select the coordinate positions of the velocity inlet and pressure outlet of the air flow, relative atmospheric pressure, 0 Pa, and set the corresponding velocity, temperature, and turbulence parameters.

[0029] S2-2-3: Define the wall type and set the boundary conditions of the air flow. The boundary conditions include no-slip state, non-deformable collision, and no heat exchange considered.

[0030] In the above solution: Step S3 further includes the following steps:

[0031] S3-1: Turn on the discrete phase model of the fluid simulation software and define it as a two-way coupling, the interaction mode between particles and fluid.

[0032] S3-2: Define the properties of the dust particles. The properties of the dust particles include particle material, density of the dust particles, and shape.

[0033] S3-3: Set the sides and rear of the front and rear drums of the shearer as dust-emitting surfaces and set the parameters of the dust-emitting surfaces.

[0034] S3-4: Define the collision behavior, bounce coefficient, adhesion probability, and fragmentation model of the particles with the wall.

[0035] S3-5: Turn on the two-way coupling and define the influence of the particles on the fluid momentum, energy, and chemical components.

[0036] S3-6: Set the solution control parameters; select the numerical method in "Solution Methods", and select SIMPLEC for the pressure-velocity coupling algorithm; define the relaxation factor in "Solution Controls" and set the residual convergence criterion to 1e -06 ;

[0037] S3-7: Set the time interval for automatic saving according to the simulation time.

[0038] S3-8: Set the simulation duration.

[0039] S3-9: Set the number of iterations or time steps;

[0040] S3-10: Simulate the generated dust particles, monitor the changes in the residual curve and key variables to ensure the calculation convergence; after the simulation is completed, export the dust particle simulation data. The specific dust particle simulation data includes the data and case files of the simulation results.

[0041] In the above solution: Step S3-3 further includes the following steps:

[0042] S3-3-1: Determine the coordinates of any dust-emitting surface;

[0043] S3-3-2: Select the dust type and dust-emitting direction of the dust-emitting surface, define the initial temperature of the dust particles, and set the mass flow rate and wind speed pressure of the dust particles;

[0044] S3-3-3: Repeat steps S3-3-1 to S3-3-2 until all dust-emitting surfaces are set.

[0045] In the above solution: Step S4 further includes the following steps:

[0046] S4-1: Import the simulation data of the air flow field and dust particles into the post-processing software. The post-processing software in this embodiment is CFD-Post, draw the flow field distribution, analyze the flow field characteristics, and export the continuous phase data;

[0047] S4-2: View the discrete phase results, draw the particle trajectories, analyze the particle deposition distribution, statistically output the particle-related data, and generate a simulation animation;

[0048] S4-3: Analyze the air flow trace diagram, air flow cloud diagram, dust spatio-temporal evolution diagram, XY plane diagram of dust concentration distribution, and ZX plane diagram of dust concentration distribution in the post-processing software;

[0049] S4-4: Compare the simulation live diagram and data diagram with the actual situation. If the difference exceeds the error tolerance range, repeat steps S2 to S4 and adjust the corresponding air flow and dust particle parameters until the difference is within the error tolerance range.

[0050] In summary, the beneficial effects of the present invention are as follows: Through numerical simulation using the turbulent flow mathematical model and the DPM mathematical model, the air flow is first regarded as a continuous phase, and the Euler method is used to describe the fluid motion in the fully mechanized coal mining face. Subsequently, the dust particles are regarded as a discrete phase, and a mathematical model is established using the Euler-Lagrange method to simulate the diffusion process of fog dust in the fully mechanized coal mining face. By performing numerical simulation on the fully mechanized tunneling face, the diffusion of dust under the action of air flow disturbance is studied, providing a guarantee for proposing more reasonable dust reduction measures and providing theoretical guidance for dust prevention and mine environmental protection. It can achieve multi-field coupling simulation of the underground air flow field, dust field, etc., and realize the three-dimensional spatial measurement and analysis of the dust field under the influence of factors such as different air flow magnitudes and dust migration positions. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is the flow chart of the present invention.

[0052] Figure 2 is the schematic diagram of the geometric model.

[0053] Figure 3 is the grid division diagram of the geometric model.

[0054] Figure 4 is the bar chart of the model grid quality distribution.

[0055] Figure 5 is the independence test of 4 grid schemes.

[0056] Figure 6 is the simulated streamline diagram of the air flow.

[0057] Figure 7 is the air flow velocity contour map.

[0058] Figure 8 is the XZ plane diagram of the dust concentration distribution.

[0059] Figure 9 is the ZX plane diagram of the dust concentration distribution.

[0060] Figure 10 is the particle size distribution diagram of the working face dust.

[0061] Figure 11 is Figure 10 the bar chart of the proportion of each particle size in

[0062] Figure 12 is the dust concentration distribution map. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0063] The present invention will be further described below through embodiments in conjunction with the drawings:

[0064] As Figures 1 to 12As shown in the figure, a numerical simulation method for the breathing hemisphere of a shearer driver in a fully mechanized coal mining face includes the following steps:

[0065] S1: Establish a geometric model of the construction site;

[0066] S1-1: Draw the geometric model; Use SolidWorks software to establish an equiscale geometric model, which is drawn according to requirements. The geometric model consists of the working space of the face, hydraulic supports, shearers, and scraper conveyors. The length, width, and height of the working space are 120m×10m×6.8m respectively;

[0067] S1-2: In the large environment of the fully mechanized coal mining face, establish a driver breathing hemisphere model in the working area of the shearer driver; The breathing hemisphere is a hemispherical range with the mouth and nose of the shearer driver as the center of the sphere and the front side of the face, representing the inhalable dust within the driver's breathing range;

[0068] S1-3: Determine the grid scheme during simulation;

[0069] S1-3-1: Conduct grid division in the large environment of the fully mechanized coal mining face and within the breathing hemisphere respectively, and formulate multiple grid schemes; Adopt polyhedra type grids, optimize the poor-quality local grids by eliminating the fragmented parts, and add 6 boundary layers;

[0070] Import the file of the geometric model into Mesh, and use tetrahedral grids for grid division through the curvature size of the grids and the minimum size between adjacent grids. At the same time, set 4 grid schemes with different grid sizes for grid independence test to ensure the best grid scheme is adopted during calculation;

[0071] S1-3-2: Select measurement points and use the data of the measurement points as the verification parameters for grid independence test;

[0072] Select 10 measurement points at equal intervals at the breathing zone height in the sidewalk area of the working face to obtain the air flow velocity, and use the air flow velocity as the verification parameter for grid independence test;

[0073] S1-3-3: Compare the four grid schemes according to the data of the measurement points, and adopt the grid division scheme when the calculation results no longer change as the final grid scheme;

[0074] S1-3-4: Import the final grid scheme into Fluent, first adjust the scale to ensure that the size of the physical model is consistent with the actual size, and check the grid quality.

[0075] S2: Regard the air flow as a continuous phase and simulate the fluid movement trajectory of the fully mechanized coal mining face;

[0076] S2-1: Open the steady-state environment in the fluid simulation software and enable the turbulence model; among them, the fluid simulation software is Fluent;

[0077] S2-2: Set the initial conditions of the air flow;

[0078] S2-2-1: Select the Pressure-Based Solver and set it for transient simulation;

[0079] S2-2-2: Select the coordinate positions of the velocity inlet and pressure outlet of the air flow, relative to the atmospheric pressure, 0 Pa, and set the corresponding velocity, temperature, and turbulence parameters (5e -08 kg / s);

[0080] S2-2-3: Define the wall type and set the boundary conditions of the air flow, and the boundary conditions include no-slip state, collision non-deformation, and no heat exchange considered;

[0081] S2-3: Simulate the air flow state. After the simulation is completed, export the simulation data and corresponding files of the air flow field;

[0082] S2-4: Import the simulation data and corresponding files of the air flow field into the fluid simulation software again, convert the steady-state environment into a transient environment, and set the gravitational acceleration to 9.81 m / s according to the model direction 2 ;

[0083] S3: Regard the dust particles as the discrete phase and simulate the diffusion process of the fog dust in the fully-mechanized coal mining face;

[0084] S3-1: Enable the discrete phase model of the fluid simulation software and define it as a two-way coupling, the interaction mode between particles and fluid;

[0085] S3-2: Define the properties of the dust particles; the properties of the dust particles include particle material, density of the dust particles, shape, among which, the density of the dust particles is 1390 kg / m 3 , and the shape factor is spherical particles;

[0086] S3-3: Set the side and back of the front and rear drums of the shearer as the dust generation surfaces and set the parameters of the dust generation surfaces;

[0087] S3-3-1: Determine the coordinates of any dust generation surface;

[0088] S3-3-2: Select the dust type and dust generation direction of the dust generation surface, define the initial temperature of the dust particles, and set the mass flow rate, wind speed pressure of the dust particles;

[0089] S3-3-3: Repeat steps S3-3-1 to S3-3-2 until all dust-emitting surfaces are set up;

[0090] S3-4: Define the collision behavior, bounce coefficient, adhesion probability, and fragmentation model of particles with the wall in "Wall Interaction";

[0091] S3-5: Turn on two-way coupling and define the influence of particles on fluid momentum, energy, and chemical components;

[0092] S3-6: Set the solution control parameters; select the numerical method in "Solution Methods", and choose SIMPLEC for the pressure-velocity coupling algorithm; define the relaxation factor in "Solution Controls" and set the residual convergence criterion to 1e -06 ;

[0093] S3-7: Set the time interval for automatic saving according to the simulation time; specifically: open the Autosave tab in CalculationActivities, set Save Data File Every in combination with the numerical simulation time, and set Save Associated Case Files to Each Time;

[0094] S3-8: Set the simulation duration; set the Time Step Size and Numberof Time Steps in Calculation Activities, and select an appropriate simulation duration on the premise of ensuring simulation accuracy;

[0095] S3-9: Set the number of iterations or time steps in Run Calculation;

[0096] S3-10: Simulate the generated dust particles, monitor the changes in the residual curve and key variables to ensure calculation convergence; after the simulation is completed, export the dust particle simulation data, and the specific dust particle simulation data includes the data and case files of the simulation results;

[0097] S4: Data analysis;

[0098] S4-1: Import the simulation data of the air flow field and dust particles into the post-processing software. The post-processing software in this embodiment is CFD-Post, draw the flow field distribution, analyze the flow field characteristics, and export the continuous phase (gas phase) data;

[0099] S4-2: View the discrete phase results, draw the particle trajectories, analyze the particle deposition distribution, statistically output the particle-related data (such as velocity, morphology, etc.), and generate a simulation animation;

[0100] S4-3: Analyze the air flow trace diagram, air flow cloud diagram, dust spatio-temporal evolution diagram, XY plane diagram of dust concentration distribution, and ZX plane diagram of dust concentration distribution in the post-processing software;

[0101] S4-4: Compare the simulation live diagram and data diagram with the actual situation. If the difference exceeds the allowable error range, repeat steps S2 - S4 and adjust the parameters of the corresponding air flow and dust particles until the difference is within the allowable error range.

[0102] Among them, Specific Heat Capacity is set to 1200 J / (kg·K), Thermal Conductivity is set to 0.3 W / (m·K), Sliding and Rolling Behavior is set to 0.08, Sticking Probability is set to 0.3, Friction Coefficient is set to 0.6, and Restitution Coefficient is set to 0.4.

[0103] The mathematical model of this method is as follows:

[0104] Since the Reynolds number of the fully mechanized coal mining face is generally greater than 1×10^6, the air flow state is turbulent. The air flow-dust migration process in the fully mechanized coal mining face is very complex, and the specific equations are as follows:

[0105] (1) Continuity equation:

[0106]

[0107] In the formula: ρ - density (kg·m^-3); x - coordinate (m); u - velocity vector (m·s^-1); t - time (s); i - tensor index symbol.

[0108] (2) Standard equation

[0109] Turbulent pulsation kinetic energy equation:

[0110]

[0111] Turbulent pulsation kinetic energy dissipation rate equation:

[0112]

[0113] In the formula: k is the turbulent kinetic energy, m 2 / s 2 ; G k - Influence coefficient of the change rate of turbulent kinetic energy affected by the change of shear force, [kg·(s^-3·m^-1)]; G b - Turbulent kinetic energy caused by the influence of buoyancy; C 1ε, C 2ε , σ ε , σ k - constant; μ eff is the viscosity coefficient; a k is the reciprocal of the effective Prandtl of the turbulent kinetic energy, taking 1.0; ε is the turbulent kinetic energy, m 2 / s 3 ; j is the tensor index symbol.

[0114] The force balance equation of the particle phase is as follows:

[0115]

[0116] In the formula, m p — dust mass (mg); u p — dust migration velocity (m·s-1); ∑F — resultant force on the dust (N); F d — resistance force on the dust (N); F g — gravitational force on the dust (N); F f — buoyancy force on the dust (N); F X — other forces on the dust, (N).

Claims

1. A method for numerically simulating the breathing hemisphere of a coal mining machine driver in a fully mechanized working face, characterized in that: The following steps are involved: S1: Establish geometric model of construction site; S1-1: Draw the geometric model; Solidworks drawing software is used to establish a proportional geometric model of the fully mechanized coal mining face. The model is drawn according to the requirements. The geometric model consists of the working space of the working face, hydraulic support, coal mining machine, and scraper conveyor. S1-2: In the environment of fully mechanized mining face, a driver breathing hemisphere model is established in the working area of ​​the coal mining driver. The breathing hemisphere is a hemispherical range on the front side of the face with the mouth and nose of the coal mining driver as the center, representing the dust that can be inhaled within the driver's breathing range. S1-3: Determine the grid scheme for simulation; S2: The wind flow is regarded as a continuous phase to simulate the fluid movement trajectory of the fully mechanized mining working face; S3: Dust particles are regarded as discrete phases to simulate the fog and dust diffusion process in the fully mechanized mining face; S4: Data analysis and parameter adjustment.

2. The method for numerically simulating the breathing hemisphere of a coal mining machine driver in a fully mechanized working face according to claim 1 is characterized in that: The radius of the breathing hemisphere in step S1-2 is in the range of 0.4m to 0.9m; The length, width and height of the working space described in step S1-1 are respectively 120m×10m×6.8m.

3. The method for numerically simulating the breathing hemisphere of a coal mining machine driver in a fully mechanized working face according to claim 2 is characterized in that: Step S1-3 also includes the following steps: S1-3-1: Grids are divided in the large environment and breathing hemisphere of the fully mechanized mining face, and multiple grid schemes are formulated; polyhedra type grids are used to optimize local grids with poor quality by eliminating fragments and adding multiple boundary layers; Import the geometry model file into Mesh, use tetrahedral mesh to divide the mesh according to the curvature size of the mesh and the minimum size between adjacent meshes, set up multiple mesh schemes with different mesh sizes, and perform mesh independence tests to ensure that the best mesh scheme is used during calculation; S1-3-2: Select measurement points and use the data from the measurement points as verification parameters for grid independence test; A plurality of measuring points are equidistantly selected at the breathing zone height of the pedestrian area of ​​the working face to obtain the wind flow velocity, and the wind flow velocity is used as a verification parameter for the grid independence test; S1-3-3: Compare the four grid schemes based on the data of the measurement points, and use the grid division scheme when the calculation results no longer change as the final grid scheme; S1-3-4: Import the final mesh solution into Fluent. First, adjust the scale to ensure that the size of the physical model is consistent with the actual size and check the mesh quality.

4. The method for numerically simulating the breathing hemisphere of a coal mining machine driver in a fully mechanized working face according to claim 1 is characterized in that: Step S2 also includes the following steps: S2-1: Open the steady-state environment in the fluid simulation software and turn on the turbulence model; the fluid simulation software is Fluent; S2-2: Set the initial conditions of wind flow; S2-3: Simulate the wind flow state, and after the simulation is completed, export the simulation data of the wind flow field and the corresponding files; S2-4: Import the simulation data of the wind flow field and the corresponding files into the fluid simulation software again, convert the steady-state environment into a transient environment, and set the gravity acceleration according to the model direction.

5. The method for numerically simulating the breathing hemisphere of a coal mining machine driver in a fully mechanized working face according to claim 1 is characterized in that: Step S2-2 also includes the following steps: S2-2-1: Select Pressure-Based Solver and set it to transient simulation; S2-2-2: Select the coordinate positions of the velocity inlet and pressure outlet of the wind flow, relative to atmospheric pressure, 0Pa, and set the corresponding velocity, temperature and turbulence parameters; S2-2-3: Define the wall type and set the boundary conditions of the wind flow, which include no slip state, no deformation due to collision, and no consideration of heat exchange.

6. The method for numerically simulating the breathing hemisphere of a coal mining machine driver in a fully mechanized working face according to claim 1 is characterized by: Step S3 also includes the following steps: S3-1: Open the discrete phase model of the fluid simulation software, which is defined as a two-way coupling, particle and fluid interaction mode; S3-2: define the properties of dust particles; the properties of the dust particles include particle material, density and shape of the dust particles; S3-3: Assume that the sides and rear of the front and rear drums of the coal mining machine are dust generating surfaces, and set the parameters of the dust generating surfaces; S3-4: Define the collision behavior between particles and walls, rebound coefficient, adhesion probability and breakup model; S3-5: Turn on the two-way coupling to define the effect of particles on the fluid momentum, energy and chemical composition; S3-6: Set solution control parameters; select the numerical method in "Solution Methods" and select SIMPLEC for the pressure-velocity coupling algorithm; define the relaxation factor in "Solution Controls" and set the residual convergence criterion to 1e -06 ; S3-7: Set the time interval for automatic saving according to the simulation time; S3-8: Set simulation duration; S3-9: Set the number of iterations or time steps; S3-10: Simulate the generated dust particles and monitor the changes in the residual curve and key variables to ensure the convergence of the calculation; after the simulation is completed, export the dust particle simulation data, which includes the data and case files of the simulation results.

7. The method for numerically simulating the breathing hemisphere of a coal mining machine driver in a fully mechanized working face according to claim 1 is characterized by: Step S3-3 also includes the following steps: S3-3-1: Determine the coordinates of any dust-generating surface; S3-3-2: Select the dust type and dust direction of the dust generating surface, define the initial temperature of the dust particles, and set the mass flow rate, wind speed and pressure of the dust particles; S3-3-3: Repeat steps S3-3-1 to S3-3-2 until all dust generating surfaces are set.

8. The method for numerically simulating the breathing hemisphere of a coal mining machine driver in a fully mechanized working face according to claim 1 is characterized by: Step S4 also includes the following steps: S4-1: Import the simulation data of the wind flow field and dust particles into the post-processing software. The post-processing software in this embodiment is CFD-Post, draw the flow field distribution, analyze the flow field characteristics, and export the continuous phase data; S4-2: View discrete phase results, draw particle trajectories, analyze particle deposition distribution, statistically output particle-related data, and generate simulation animations; S4-3: Analyze the wind flow trace map, wind flow cloud map, dust space-time evolution map, dust concentration distribution XY plane map, and dust concentration distribution ZX plane map in the post-processing software; S4-4: Compare the simulated actual situation graph and the data graph with the actual situation. If the difference exceeds the allowable error range, repeat steps S2 to S4 and adjust the corresponding wind flow and dust particle parameters until the difference is within the allowable error range.

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