High-precision simulation method for filtering performance of mining dustproof mask fiber structure

Abstract

The invention provides a high-precision simulation method for filtering performance of a mining dustproof mask fiber structure. The high-precision simulation method comprises the following steps: establishing a randomly distributed fiber aggregate model; a transient state is activated in Fluent, a turbulence model Realizable k-epsilon is selected, the pressure drop of a mining dust mask and the flow field characteristics of nanoscale fiber gaps are simulated and predicted, a DPM model is activated, the migration track of 0.3-10 [mu] m inhalable particles is tracked, and the dust trapping process of a fiber structure is simulated in the transient state environment. By simulating the influence of different fiber diameters, fiber volume fractions, airflow flows and the like on the filtering performance of the fiber structure of the mining dust mask, the research and development of the high-filtering-performance mining dust mask can be guided in a targeted manner, and the influence of the internal fiber structure of the dust mask on the filtering performance of the dust mask is mastered.

Description

Technical Field

[0001] The present invention relates to the technical field related to fluid mechanics, and in particular to a high-precision simulation method for the filtering performance of a fiber structure of a mining dust mask. Background Art

[0002] With the increasing mechanization of industrial production, dust hazards have gradually become a global occupational health crisis, especially in coal mines with high dust concentrations. After coal dust is inhaled into miners, it is deposited in different areas of the respiratory tract during breathing, posing a serious threat to their health. Dust with an aerodynamic diameter of less than 10μm can penetrate deep into the respiratory tract and deposit in the lower respiratory tract, while dust particles with a particle size of less than 5μm can enter the alveolar region of the human body. Long-term accumulation can cause irreversible damage to lung cells. As engineering measures fail to effectively reduce dust concentrations in the working environment, wearing a high-filtration-efficiency dust mask becomes the last line of defense to prevent dust from entering the human body. Therefore, testing the filtration performance of dust masks has become a hot topic.

[0003] Traditional filtration performance testing experiments often use NaCl and oily aerosols as media, making it difficult to truly restore the filtration performance of coal dust particles. To address this situation, some scholars have begun to use numerical simulation to study the filtration efficiency and pressure drop of dust masks. Most of these studies simulate the external flow field of dust masks and obtain the pressure drop changes inside and outside the dust masks. However, due to the relatively small number of simulations of dust mask filtration efficiency and the lack of clarity on the dust capture patterns and pressure drop changes of the internal fiber structure of dust masks, it is difficult to understand the impact of the internal fiber structure of dust masks on the filtration performance of dust masks. Summary of the Invention

[0004] The present invention aims to provide a high-precision simulation method for the filtration performance of the fiber structure of a mining dust mask, so as to solve the above-mentioned problem that it is difficult to grasp the influence of the internal fiber structure of the dust mask on the filtration performance of the dust mask.

[0005] To this end, the technical solution adopted by the present invention is: a high-precision simulation method for the filtration performance of the fiber structure of a mining dust mask, comprising the following steps:

[0006] S1. Using Material Designer in Workbench software to establish a randomly distributed fiber assembly model, and saving the established randomly distributed fiber assembly model as an xt format file;

[0007] S2. Import the xt format file into Geometry software, name each part of the randomly distributed fiber assembly model, set the fluid domain, save the file, and close the Geometry software window;

[0008] S3, the completed random distribution of the fiber assembly model is imported into Mesh software for mesh division, and the mesh file after division is imported into Fluent software for wind flow simulation;

[0009] S4, activate transient, select Realizable k-epsilon as the turbulence model, and set the boundary conditions;

[0010] S5, select SIMPLE algorithm as the solving algorithm, set the time step, and start calculation. After the calculation is completed, the case and data files of the wind flow simulation are exported;

[0011] S6, the case and data files are imported into the Fluent software, the DPM model is activated, and the DPM emitter is created;

[0012] S7, compile the real-time filtration efficiency conditions of the fiber structure through Python software, and input the compiled instructions into the Fluent software through UDF;

[0013] S8, select the SIMPLE algorithm as the solving algorithm, set the time step, and start dust simulation;

[0014] S9, after the calculation is completed, the simulated data and case files are exported, and the xml files of dust particles of different particle sizes are also exported. The data file and the xml file are imported into the CFD-POST software, and the filtration effect of the fiber structure is viewed.

[0015] As a preferred embodiment of the above scheme, in the step S1, when establishing the random distribution of the fiber assembly model, open the Material Designer in the component system of the Workbench software, select RVE Model in Short Fiber Composite, select Geometry in the Outline interface, and input parameters including fiber diameter and fiber volume fraction, click to create a fiber assembly, delete the generated Fiber component in the Structure interface, and click File to save the xt format file.

[0016] Further preferably, in the step S3, when performing the mesh division, in order to ensure the accuracy of the simulation results, a mesh with an average quality higher than 0.9 is used to calculate the process.

[0017] Further preferably, in the step S4, when the transient state is activated, the fluid domain is set to be transient simulation and the size and direction of gravity are defined; the inlet face is set to be velocity-inlet, the outlet face is set to be pressure-outlet, the fiber wall face is set to be wall, and the surrounding wall face is set to be symmetry; calculation is performed under the transient environment, and the data and case files are exported after the simulation is completed.

[0018] Further preferably, in the step S6, when the DPM model is activated, the DPM emitter is created by clicking Models in the Fluent software, selecting Discrete Phase, and then clicking Injections; in the Injection interface, the Injection Type is set to be surface, and the inlet is set to be the emission face; then parameters including particle size, emission time, and total flow are set.

[0019] Further preferably, in the step S7, when the compiled instructions are input into the Fluent software through the UDF, the UDF is compiled by clicking Define in the Fluent software, selecting User-Defined, and then clicking Compile; in the Add interface, the UDF source file is selected and loaded by clicking Load; and in the Boundary Conditions interface, the target boundary is selected to set the UDF parameters.

[0020] The beneficial effects of the present application are as follows:

[0021] 1. The turbulent flow model can accurately measure the pressure gradient change between the fibers, observe the gas flow migration law and the formation area of the circulation, and clearly understand the pressure drop change of the fiber structure inside the dust mask.

[0022] 2. Combined with the DPM model and the UDF, the motion trajectory of the dust can be tracked, including particle size, concentration, and deposition position information; the filtration efficiency of the fiber structure can also be monitored in real time, so as to deeply study the interception and capture mechanism of the mine dust mask fiber structure, and clearly understand the dust capture law of the fiber structure inside the dust mask.

[0023] 3. By simulating the influence of different fiber diameters, fiber volume fractions, and airflow flow rates on the filtration performance of the mine dust mask fiber structure, the research and development of the mine dust mask with high filtration performance can be targetedly guided, and the influence of the fiber structure inside the dust mask on the filtration performance of the dust mask can be mastered. BRIEF DESCRIPTION OF DRAWINGS

[0024] Fig. 1 is the flowchart of the present application.

[0025] Fig. 2 Figure 1 is a schematic diagram of the fiber structure of the mine dust mask of the present application.

[0026] Fig. 3 Figure 2 is a filter effect diagram of the fiber structure of the mine dust mask of the present application. DETAILED DESCRIPTION

[0027] The present application will be further described below in conjunction with the accompanying drawings and examples.

[0028] As shown in Figure 3, a high-precision simulation method for the filtering performance of the fiber structure of the mine dust mask, comprising the following steps: Figs. 1-3

[0029] S1, use Material Designer in Workbench software to establish a random distribution fiber assembly model, and save the established random distribution fiber assembly model as an xt format file.

[0030] In step S1, when establishing the random distribution fiber assembly model, open Material Designer in the component system of Workbench software, select RVE Model in Short Fiber Composite. In the Outline interface, select Geometry and input fiber diameter and fiber volume fraction and other parameters, and click to create the fiber assembly. Delete the generated Fiber component in the Structure interface. Click File to save as an xt format file.

[0031] S2, import the xt format file into Geometry software, name each part of the random distribution fiber assembly model, and set the fluid domain, then save and close the Geometry software window.

[0032] S3, import the completed random distribution fiber assembly model into Mesh software for meshing, and import the mesh file divided into Fluent software for wind flow simulation.

[0033] In step S3, when meshing, considering that the fiber diameter is in the nanometer level, in order to ensure the accuracy of the simulation results, fine mesh needs to be used to calculate this process, and mesh with an average quality higher than 0.9 is preferably selected for calculation.

[0034] S4, activate transient, select Realizable k-ε as the turbulence model, and set the boundary conditions.

[0035] ​In step S4, when the transient state is activated, the fluid domain is set to transient simulation and the size and direction of gravity are specified. The inlet face is set to velocity-inlet, the outlet face is set to pressure-outlet, the fiber wall face is set to wall, and the surrounding wall face is set to symmetry. The calculation is performed in the transient environment, and after the simulation is completed, the data and case files are exported.

[0036] S5, the SIMPLE algorithm is selected as the solving algorithm, and after the time step is set, the calculation is started. After the calculation is completed, the case and data files of the air flow simulation are exported.

[0037] S6, the case and data files are imported into the Fluent software, the DPM model is activated, and the DPM emitter is created.

[0038] In step S6, when the DPM model is activated, click Models in the Fluent software, select Discrete Phase, and then click Injections to start creating the DPM emitter. In the Injection interface, set Injection Type to surface and the inlet to the emission face. Then set the particle size, emission time, and total flow, etc.

[0039] S7, compile the real-time filtration efficiency conditions of the fiber structure through the Python software, and input the compiled instructions into the Fluent software through UDF.

[0040] In step S7, when the compiled instructions are input into the Fluent software through UDF, click Define in the Fluent software, select User-Defined, and then click Compile to compile the UDF. In the Add interface, select the UDF source file and click Load to load it. Enter the Boundary Conditions interface to select the target boundary and set the UDF parameters.

[0041] S8, the SIMPLE algorithm is selected as the solving algorithm, and after the time step is set, the dust simulation is started.

[0042] S9, after the calculation is completed, the simulated data and case files are exported, and the xml files of dust particles of different particle sizes are also exported. The data files and xml files are imported into the CFD-POST software to view the filtration effect of the fiber structure.

[0043] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely divergences of the principles and application of the present application and that numerous modifications, changes, substitutions, and alterations can be made thereto without departing from the spirit and scope of the present application, which is defined by the following claims and their equivalents.

Claims

1. A high-precision simulation method for the filtration performance of the fiber structure of a mining dust mask, characterized in that: The following steps are involved: S1. Using Material Designer in Workbench software to establish a randomly distributed fiber assembly model, and saving the established randomly distributed fiber assembly model as an xt format file; S2. Import the xt format file into Geometry software, name each part of the randomly distributed fiber assembly model, set the fluid domain, save the file, and close the Geometry software window; S3, importing the completed randomly distributed fiber assembly model into Mesh software for mesh division, and importing the divided mesh file into Fluent software for wind flow simulation; S4. Activate the transient state, select the turbulence model as Realizable k–ε, and set the boundary conditions; S5. Select SIMPLE algorithm as the solution algorithm, set the time step and start the calculation. After the calculation is completed, export the case and data files of the wind flow simulation; S6. Import the case and data files into the Fluent software, activate the DPM model, and create a DPM transmitter; S7, compiling the real-time filtration efficiency condition of the fiber structure through Python software, and inputting the compiled instructions into the Fluent software through UDF; S8. Select the SIMPLE algorithm as the solution algorithm, set the time step and start the dust simulation; S9. After the calculation is completed, export the simulated data and case files, and export the xml files of dust particles with different particle sizes. Import the data files and xml files into CFD-POST software to check the filtering effect of the fiber structure.

2. A high-precision simulation method for the filtration performance of the fiber structure of a mining dust mask according to claim 1, characterized in that: In the step S1, when establishing the randomly distributed fiber aggregate model, open Material Designer in the component system of the Workbench software and select RVE Model in Short Fiber Composite; select Geometry in the Outline interface and enter parameters, including fiber diameter and fiber volume fraction, and click Create Fiber Aggregate; delete the generated Fiber component in the Structure interface; click File to save as the xt format file.

3. The high-precision simulation method for the filtration performance of the fiber structure of a mining dust mask according to claim 1 is characterized in that: In step S3, when performing the mesh division, in order to ensure the accuracy of the simulation results, it is necessary to use a mesh with an average quality higher than 0.9 to calculate the process.

4. The high-precision simulation method for the filtration performance of the fiber structure of a mining dust mask according to claim 1 is characterized in that: In step S4, when the transient state is activated, the fluid domain is set to a transient simulation and the magnitude and direction of gravity are specified; the air inlet surface is set to velocity-inlet, the air outlet surface is set to pressure-outlet, the fiber wall surface is set to wall, and the surrounding walls are set to symmetry; calculations are performed in a transient environment, and the data and case files are exported after the simulation is completed.

5. The high-precision simulation method for the filtration performance of the fiber structure of a mining dust mask according to claim 1 is characterized in that: In step S6, when the DPM model is activated, click Models in the Fluent software, select Discrete Phase, and then click Injections to start creating the DPM emitter; in the Injection interface, set the Injection Type to surface and the air inlet to the emission surface; then set parameters, including particle size, emission time, and total flow rate.

6. The high-precision simulation method for the fiber structure and filtration performance of a mining dust mask according to claim 1 is characterized in that: In step S7, when the compiled instructions are input into the Fluent software through the UDF, click Define in the Fluent software, select User-Defined, and then click Compile to compile the UDF; in the Add interface, select the UDF source file and click Load to load it; enter the Boundary Conditions interface to select the target boundary and set the UDF parameters.

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