Method for determining average wind speed distribution position of section of mine laneway

Abstract

The invention provides a method for determining an average wind speed distribution position of a mine laneway section. The method comprises the steps of 3D MAX geometric modeling, model mesh generation, ANSYS Fluent boundary condition setting and analogue simulation, geometry and flow field data dimensionless, and determination of a dimensionless distance between a wall surface and a constant-speed ring distribution position and a constant-speed ring approximate circle equation. According to the method, the conclusion obtained through nondimensionalization of the wind speed and the common arched roadway size is more universal, and the nondimensional distance between the vault and the roadway side wall and the constant-speed ring in the laminar flow state and the turbulent flow state, the nondimensional circle center coordinates of the constant-speed ring in the turbulent flow state and the equation of the nondimensional circle formed through fitting according to the four corners of the roadway are obtained; an experiment basis is provided for on-site roadway wind speed sensor installation. By adopting the method for determining the mounting positions of the wind speed sensors suitable for the arched roadways of different sizes in different wind speed flow states, an efficient mine roadway wind speed monitoring system can be established, and the method has important practical significance in accurate measurement of the wind quantity of a mine ventilation roadway and safety production.

Description

Technical Field

[0001] The present invention relates to a method for determining the average wind speed distribution position, and in particular to a method for determining the average speed distribution position of a mine tunnel section, and belongs to the technical field of mine tunnel ventilation measurement. Background Art

[0002] As mining progresses deeper, ventilation networks become more complex. The measurement of average wind speed in ventilation tunnels is a guarantee for safe operation of personnel and equipment underground. At present, the main method for measuring wind speed in mine tunnels is online monitoring, which involves hanging wind speed sensors vertically on the tunnel wall for real-time measurement. At present, wind speed measurement products used in mines are mainly designed based on ultrasonic, impeller and hot wire principles, and they all need to be calibrated when used. The accuracy of wind speed measurement depends on the sensor accuracy, installation location and wall roughness.

[0003] In the traditional manual measurement method of underground wind speed, it is difficult to accurately measure the average wind speed on the tunnel section due to human subjectivity and the human body affecting the distribution of wind flow. In addition, the air environment underground is poor. In some tunnels, especially the return air tunnel, it is difficult to measure manually. Online wind speed detection can avoid the disadvantages of difficult manual measurement, reduce the consumption of manpower and material resources, and has high measurement accuracy. At present, the accuracy of mine wind speed sensors can meet the requirements of industrial applications. With the popularization of computer and other technologies, online monitoring methods have dominated the measurement of tunnel air volume, but the determination of the installation position that can reflect the average speed of the tunnel section is still a problem. Summary of the invention

[0004] The present invention provides a method for determining the average wind speed distribution position of a mine arch tunnel section, so as to solve the problem that it is difficult to determine the specific installation position of a wind speed sensor in the arch tunnel and establish an efficient mine tunnel wind speed monitoring system.

[0005] The technical solution of the present invention is achieved in this way:

[0006] A method for determining the average wind speed distribution position of a mine tunnel section, characterized by comprising the following technologies:

[0007] J1. Establishment of the roadway geometry model: Use 3D MAX to model the measured roadway and ensure that the model length is greater than or equal to the turbulence fully developed length;

[0008] J2. Discretize the geometric model: discretize the model into hexahedral grids, and ensure that the grid in the center of the tunnel is dense and the grid near the wall is relatively sparse;

[0009] J3. Set boundary conditions and import the model into the software for calculation: Import the model into ANSYS Fluent, select the standard k-epsilon model and enhanced wall functions, set the inlet as velocity inlet, the outlet as pressure outlet, and the wall as no-slip wall; set the inlet flow velocity to laminar flow and turbulent flow in the Reynolds number partition of the model, and obtain the flow field results under different partitions;

[0010] J4. Make the model size and flow velocity dimensionless: divide the model length and width by the actual length and width, and divide the velocity by the set inlet velocity;

[0011] J5. Determine the dimensionless distance of the average velocity distribution ring from the top and sidewall of the roadway: export the data through ANSYS Fluent and obtain the dimensionless distance by arithmetic mean method;

[0012] J6. Determine the center coordinates and radius of the dimensionless constant velocity ring: define the dimensionless coordinates at the maximum value of the dimensionless velocity of the cross section of the model as the center coordinates, and fit the scattered points of the constant velocity rings at the four corners of the roadway into a circle by the least squares method to obtain the dimensionless radius;

[0013] J7. When applying, roughly measure the actual wind speed in the tunnel to determine the Reynolds number partition: use hot wire anemometer and other wind speed measuring equipment to roughly measure the wind speed in the tunnel section, and use 2100 as the boundary to determine the flow state;

[0014] J8. Calculate the actual distance between the average velocity distribution ring of the tunnel cross section and the tunnel top and side wall: Use the dimensionless distance obtained in J5 to reversely calculate the actual distance;

[0015] J9, determine the actual center coordinates and actual radius of the constant velocity ring: by using the dimensionless center coordinates and radius of the constant velocity ring determined by J6, calculate the actual center coordinates and actual radius;

[0016] J10, install wind speed sensor: calculate the actual distance through J8 and the actual center coordinates and actual radius through J9, and install it at the top, side wall or four corners of the tunnel by custom.

[0017] A method for determining the average wind speed distribution position of a mine tunnel section is characterized by comprising the following steps:

[0018] S1, with Reynolds number 2100 as the boundary, less than 2100 is defined as laminar flow, and greater than 2100 is defined as turbulent flow;

[0019] S2. Use 3D MAX modeling software to establish the geometric model of the tunnel according to the actual situation of the tunnel to be studied and ensure that the model length is greater than or equal to the turbulent full development length;

[0020] S3, discretizing the geometric model generated in step S2 into a hexahedral grid based on the finite volume method; the grid at the geometric center is encrypted, and the grid near the wall is relatively sparse;

[0021] S4, import the geometric model discretized in step S3 into ANASYS Fluent, set the boundary conditions of the computational domain; set the turbulence model to the standard k-epsilon model, select enhanced wall functions for the wall function, the inlet to the velocity inlet, the outlet to the pressure outlet, and the wall to the no-slip wall;

[0022] S5, repeat step S4, and perform multiple groups of numerical experiments in the partitions described in S1;

[0023] S6. Analyze the average velocity distribution position law of different partitions in S1 at the fully developed turbulence according to the numerical calculation results of steps S4 and S5; the analysis process firstly converts the cross-sectional dimensions of the geometric model into dimensionless according to the length and width, and converts the flow velocity obtained by the numerical simulation into dimensionless respectively;

[0024] S7, according to the result of step S6, respectively obtain the dimensionless distances h(-) and d(-) of the average velocity distribution ring in the partition described in S1 from the top and side wall of the roadway;

[0025] S8. According to the results of S6, the dimensionless coordinates of the maximum dimensionless velocity in the transverse and longitudinal directions of the cross section of the S2 model are determined respectively. The coordinates are the dimensionless coordinates of the center of the constant velocity ring (a, b);

[0026] S9, according to the results of steps S6 and S8, the dimensionless coordinates of the scattered points of the isovelocity rings at the four corners of the roadway are fitted into a circle using the least squares method to obtain the dimensionless radius r(-);

[0027] S10. When applied on site, roughly measure the wind speed in the tunnel, calculate and determine the Reynolds number partition described in S1;

[0028] S11, according to the result of S7, reversely calculate the actual distance d, h;

[0029] S12, according to the results of S8 and S9, determine the actual center coordinates (A, B) and the actual radius R;

[0030] S13. Customize the installation of wind speed sensors at the distribution positions of the constant velocity rings.

[0031] Compared with the prior art, the advantages of the present invention are obvious, mainly manifested in:

[0032] 1. The wind speed and the common arched tunnel dimensions are dimensionless, and the conclusions obtained are more universal;

[0033] 2. The dimensionless distances between the vault and the sidewall of the tunnel and the constant velocity ring under laminar and turbulent flow conditions, the dimensionless center coordinates of the constant velocity ring under turbulent flow conditions, and the equation of the dimensionless circle fitted according to the four corners of the tunnel were obtained, which provided an experimental basis for the installation of on-site tunnel wind speed sensors;

[0034] 3. The influence of the real tunnel wall (such as the influence of different support methods on the dimensionless constant velocity ring) is considered. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The present invention has attached Figure 5 Of which:

[0036] Figure 1 It is the flow chart of the present invention and the actual engineering application flow chart;

[0037] Figure 2 is a schematic cross-sectional view of an arched tunnel of the present invention;

[0038] Figure 3 is a three-dimensional schematic diagram of the arched tunnel of the present invention;

[0039] Figure 4 It is a schematic diagram of the dimensionless distances d(-), h(-) between the arch and the side wall of the roadway and the constant velocity ring of the present invention;

[0040] Figure 5 It is a schematic diagram of the dimensionless constant velocity ring distribution at the four corners of the laneway of the present invention; DETAILED DESCRIPTION

[0041] like Figure 1 , 2 A method for determining the average wind speed distribution position of a mine tunnel section shown in , 3, 4, and 5 is characterized by including the following technologies:

[0042] J1. Establishment of the roadway geometry model: Use 3D MAX to model the measured roadway and ensure that the model length is greater than or equal to the turbulence fully developed length;

[0043] J2. Discretize the geometric model: discretize the model into hexahedral grids, and ensure that the grid in the center of the tunnel is dense and the grid near the wall is relatively sparse;

[0044] J3. Set boundary conditions and import the model into the software for calculation: Import the model into ANSYS Fluent, select the standard k-epsilon model and enhanced wall functions, set the inlet as velocity inlet, the outlet as pressure outlet, and the wall as no-slip wall; set the inlet flow velocity to laminar flow and turbulent flow in the Reynolds number partition of the model, and obtain the flow field results under different partitions;

[0045] J4. Make the model size and flow velocity dimensionless: divide the model length and width by the actual length and width, and divide the velocity by the set inlet velocity;

[0046] J5. Determine the dimensionless distance of the average velocity distribution ring from the top and sidewall of the roadway: export the data through ANSYS Fluent and obtain the dimensionless distance by arithmetic mean method;

[0047] J6. Determine the center coordinates and radius of the dimensionless constant velocity ring: define the dimensionless coordinates at the maximum value of the dimensionless velocity of the cross section of the model as the center coordinates, and fit the scattered points of the constant velocity rings at the four corners of the roadway into a circle by the least squares method to obtain the dimensionless radius;

[0048] J7. When applying, roughly measure the actual wind speed in the tunnel to determine the Reynolds number partition: use hot wire anemometer and other wind speed measuring equipment to roughly measure the wind speed in the tunnel section, and use 2100 as the boundary to determine the flow state;

[0049] J8. Calculate the actual distance between the average velocity distribution ring of the tunnel cross section and the tunnel top and side wall: Use the dimensionless distance obtained in J5 to reversely calculate the actual distance;

[0050] J9, determine the actual center coordinates and actual radius of the constant velocity ring: by using the dimensionless center coordinates and radius of the constant velocity ring determined by J6, calculate the actual center coordinates and actual radius;

[0051] J10, install wind speed sensor: calculate the actual distance through J8 and the actual center coordinates and actual radius through J9, and install it at the top, side wall or four corners of the tunnel by custom.

[0052] A method for determining the average wind speed distribution position of a mine tunnel section is characterized by comprising the following steps:

[0053] S1, with Reynolds number 2100 as the boundary, less than 2100 is defined as laminar flow, and greater than 2100 is defined as turbulent flow;

[0054] S2. Use 3D MAX modeling software to establish the geometric model of the tunnel according to the actual situation of the tunnel to be studied and ensure that the model length is greater than or equal to the turbulent full development length;

[0055] S3, discretizing the geometric model generated in step S2 into a hexahedral grid based on the finite volume method; the grid at the geometric center is encrypted, and the grid near the wall is relatively sparse;

[0056] S4, import the geometric model discretized in step S3 into ANASYS Fluent, set the boundary conditions of the computational domain; set the turbulence model to the standard k-epsilon model, select enhanced wall functions for the wall function, the inlet to the velocity inlet, the outlet to the pressure outlet, and the wall to the no-slip wall;

[0057] S5, repeat step S4, and perform multiple groups of numerical experiments in the partitions described in S1;

[0058] S6. Analyze the average velocity distribution position law of different partitions in S1 at the fully developed turbulence according to the numerical calculation results of steps S4 and S5; the analysis process firstly converts the cross-sectional dimensions of the geometric model into dimensionless according to the length and width, and converts the flow velocity obtained by the numerical simulation into dimensionless respectively;

[0059] S7, according to the result of step S6, respectively obtain the dimensionless distances h(-) and d(-) of the average velocity distribution ring in the partition described in S1 from the top and side wall of the roadway;

[0060] S8. According to the results of S6, the dimensionless coordinates of the maximum dimensionless velocity in the transverse and longitudinal directions of the cross section of the S2 model are determined respectively. The coordinates are the dimensionless coordinates of the center of the constant velocity ring (a, b);

[0061] S9, according to the results of steps S6 and S8, the dimensionless coordinates of the scattered points of the isovelocity rings at the four corners of the roadway are fitted into a circle using the least squares method to obtain the dimensionless radius r(-);

[0062] S10. When applied on site, roughly measure the wind speed in the tunnel, calculate and determine the Reynolds number partition described in S1;

[0063] S11, according to the result of S7, reversely calculate the actual distance d, h;

[0064] S12, according to the results of S8 and S9, determine the actual center coordinates (A, B) and the actual radius R;

[0065] S13. Customize the installation of wind speed sensors at the distribution positions of the constant velocity rings.

Claims

1. A method for determining the average wind speed distribution position of a mine tunnel section, characterized in that: The following technologies are included: J1. Establishment of the roadway geometry model: Use 3D MAX to model the measured roadway and ensure that the model length is greater than or equal to the turbulence fully developed length; J2. Discretize the geometric model: discretize the model into hexahedral grids, and ensure that the grid in the center of the tunnel is dense and the grid near the wall is relatively sparse; J3. Set boundary conditions and import the model into the software for calculation: Import the model into ANSYS Fluent, select the standard k-epsilon model and enhanced wall functions, set the inlet as velocity inlet, the outlet as pressure outlet, and the wall as no-slip wall; set the inlet flow velocity to laminar flow and turbulent flow in the Reynolds number partition of the model, and obtain the flow field results under different partitions; J4. Make the model size and flow velocity dimensionless: divide the model length and width by the actual length and width, and divide the velocity by the set inlet velocity; J5. Determine the dimensionless distance of the average velocity distribution ring from the top and sidewall of the roadway: export the data through ANSYS Fluent and obtain the dimensionless distance by arithmetic mean method; J6. Determine the center coordinates and radius of the dimensionless constant velocity ring: define the dimensionless coordinates at the maximum value of the dimensionless velocity of the cross section of the model as the center coordinates, and fit the scattered points of the constant velocity rings at the four corners of the roadway into a circle by the least squares method to obtain the dimensionless radius; J7. When applying, roughly measure the actual wind speed in the tunnel to determine the Reynolds number partition: use hot wire anemometer and other wind speed measuring equipment to roughly measure the wind speed in the tunnel section, and use 2100 as the boundary to determine the flow state; J8. Calculate the actual distance between the average velocity distribution ring of the tunnel cross section and the tunnel top and side wall: Use the dimensionless distance obtained in J5 to reversely calculate the actual distance; J9, determine the actual center coordinates and actual radius of the constant velocity ring: by using the dimensionless center coordinates and radius of the constant velocity ring determined by J6, calculate the actual center coordinates and actual radius; J10, install wind speed sensor: calculate the actual distance through J8 and the actual center coordinates and actual radius through J9, and install it at the top, side wall or four corners of the tunnel by custom. A method for determining the average wind speed distribution position of a mine tunnel section is characterized by comprising the following steps: S1, with Reynolds number 2100 as the boundary, less than 2100 is defined as laminar flow, and greater than 2100 is defined as turbulent flow; S2. Use 3D MAX modeling software to establish the geometric model of the tunnel according to the actual situation of the tunnel to be studied and ensure that the model length is greater than or equal to the turbulent full development length; S3, discretizing the geometric model generated in step S2 into a hexahedral grid based on the finite volume method; the grid at the geometric center is encrypted, and the grid near the wall is relatively sparse; S4, import the geometric model discretized in step S3 into ANASYS Fluent, set the boundary conditions of the computational domain; set the turbulence model to the standard k-epsilon model, select enhanced wall functions for the wall function, the inlet to the velocity inlet, the outlet to the pressure outlet, and the wall to the no-slip wall; S5, repeat step S4, and perform multiple groups of numerical experiments in the partitions described in S1; S6. Analyze the average velocity distribution position law of different partitions in S1 at the fully developed turbulence according to the numerical calculation results of steps S4 and S5; the analysis process firstly converts the cross-sectional dimensions of the geometric model into dimensionless according to the length and width, and converts the flow velocity obtained by the numerical simulation into dimensionless respectively; S7, according to the result of step S6, respectively obtain the dimensionless distances h(-) and d(-) of the average velocity distribution ring in the partition described in S1 from the top and side wall of the roadway; S8. According to the results of S6, the dimensionless coordinates of the maximum dimensionless velocity in the transverse and longitudinal directions of the cross section of the S2 model are determined respectively. The coordinates are the dimensionless coordinates of the center of the constant velocity ring (a, b); S9, according to the results of steps S6 and S8, the dimensionless coordinates of the scattered points of the isovelocity rings at the four corners of the roadway are fitted into a circle using the least squares method to obtain the dimensionless radius r(-); S10. When applied on site, roughly measure the wind speed in the tunnel, calculate and determine the Reynolds number partition described in S1; S11, according to the result of S7, reversely calculate the actual distance d, h; S12, according to the results of S8 and S9, determine the actual center coordinates (A, B) and the actual radius R; S13. Customize the installation of wind speed sensors at the distribution positions of the constant velocity rings.

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