An intelligent identification method for influencing factors of gas emission volume in a mining face

Abstract

The present invention discloses an intelligent identification method for influencing factors of gas emission amount in the excavation face, which includes the following steps: creating 10 layers in the mine CAD drawing; respectively using closed spline curves to divide the closed areas on the corresponding layers of the mine CAD drawing according to five factors including major faults, coal seam dip angle, coal seam thickness, equivalent lithology, and syncline and anticline basins, and using the ray method to determine the specific factor values of these five factors; taking the elevation of the coal seam floor contour line passing through the predicted excavation face as the depth of the predicted excavation face; determining the small fault factor value according to the number of small faults within the range of the excavation face; calculating the fold ratio for each contour line within the excavation face to determine the fold ratio factor value; searching for the gob area overlapping with the predicted excavation face to determine the gob area factor value. The present invention can effectively improve the prediction efficiency of gas emission amount, improve the prediction accuracy, and provide very valuable guidance for the prevention and control of mine gas disasters and the efficient ventilation of mines.

Description

Technical Field

[0001] The present invention relates to the field of coal mine safety, and in particular to an intelligent determination method for influencing factors of gas emission volume in the excavation and mining face. Background Art

[0002] For a long time, in the research on the prediction of gas emission volume in the excavation and mining face at home and abroad, the compatibility in aspects such as pertinence and generality, timeliness and accuracy, theoreticality and practicability has always been a problem that has not been solved. Aiming at the technical defects existing in the application of coal mine gas prediction, Kailuan (Group) Co., Ltd. and Hunan University of Science and Technology cooperated to carry out the research project on non-contact dynamic prediction and its correction technology for gas emission volume in the excavation and mining face. Based on the establishment of the equivalent layer theory of coal seam gas emission and the quantification method of influencing factors, the dynamic prediction and dynamic correction technology was further determined. Among them, the equivalent layer division is carried out between the equivalent lithologies of adjacent boreholes, and the influencing factors (19 - 20 items) are all non-contact options, and the quantification range covers coal seam occurrence, geological structure, mining technology and production environment; there are 20 items in 60 sections for tunneling and 19 items in 62 sections for coal mining. In the process of using this method to predict the gas emission volume, the determination of these factors by different personnel will bring a certain degree of fluctuation, thus affecting the accuracy of the prediction results and having an adverse impact on the high-efficiency energy conservation of the mine ventilation system. Summary of the Invention

[0003] In order to solve the above technical problems, the present invention provides an intelligent determination method for influencing factors of gas emission volume in the excavation and mining face, which is convenient to operate and has accurate prediction results.

[0004] The purpose of the present invention and the main technical problems to be solved are achieved by adopting the following technical solutions: An intelligent identification method for influencing factors of gas emission volume in the excavation and mining face, comprising the following steps:

[0005] 1) Establish 10 new layers in the mine CAD drawing, and the layer names are major fault, coal seam dip angle, coal seam thickness, equivalent lithology, syncline and basin, floor contour line, minor fault, fold, goaf annual and prediction range respectively;

[0006] 2) In the major fault layer of the mine CAD drawing, divide it into three closed areas of <50m, 50 - 100m, >100m with a closed spline curve according to the distance from the major fault intersection line; and mark <50m, 50 - 100m, >100m respectively in the three closed areas of <50m, 50 - 100m, >100m;

[0007] 3) In the coal seam dip angle layer of the mine CAD drawing, use a closed spline curve to draw a closed area for the area where the coal seam dip angle < 15°, and mark the text "<15°" within this area. Use a closed spline curve to draw a closed area for the area where the coal seam dip angle is 15 - 25°, and mark the text "15 - 25°" within this area. Use a closed spline curve to draw a closed area for the area where the coal seam dip angle > 25°, and mark the text ">25°" within this area;

[0008] 4) In the coal seam thickness layer of the mine CAD drawing, use a closed spline curve to draw a closed area for the area where the coal seam thickness < 2m, and mark the text "<2m" within this area. Use a closed spline curve to draw a closed area for the area where the coal seam thickness is 2 - 4m, and mark the text "2 - 4m" within this area. Use a closed spline curve to draw a closed area for the area where the coal seam thickness > 4m, and mark the text ">4m" within this area;

[0009] 5) In the equivalent lithology layer of the mine CAD drawing, according to the different equivalent lithologies, use a closed spline curve to divide the mine CAD drawing into seven closed areas: silt, fine sand, medium - fine, medium sand, coarse sand, clay, and thick mud; and mark the text "silt", "fine sand", "medium - fine", "medium sand", "coarse sand", "clay", "thick mud" within the corresponding closed areas respectively;

[0010] 6) In the syncline - anticline basin zoning layer of the mine CAD drawing, use a closed spline curve to connect all the points with the shortest distance to the syncline - anticline axis = 100m to form a closed area, and mark the text "<100m" within the closed area. Use a closed spline curve to connect all the points with the shortest distance to the syncline - anticline axis satisfying = 200m to form a closed area, and mark the text "100 - 200m" within the closed area where the shortest distance to the syncline - anticline axis is between 100 - 200m. Mark the text ">200m" within the closed area where the shortest distance to the syncline - anticline axis > 200m; Use a closed spline curve to draw the basin boundary, and mark the text "inside the basin" within the closed area;

[0011] 7) In the coal seam floor contour layer of the mine CAD drawing, mark the elevation of each floor contour near its endpoints;

[0012] 8) In the goaf layer of the mine CAD drawing, the goaf ranges of different years are all represented by closed areas, and each area is marked with the year;

[0013] 9) In the forecast range layer of the mine CAD drawing, draw a rectangular closed area representing the boundary of the mining and excavation face;

[0014] 10) Use the ray method to sequentially determine the relative positional relationships between the corner points of the working face boundary and the major faults, coal seam dip angle, coal seam thickness, equivalent lithology, and each closed area in the syncline and anticline basin strata. When any corner point of the predicted working face boundary is within a certain closed area, the predicted working face is affected by the factor corresponding to that closed area, and the factor value is the specific value marked in that closed area; if any corner point of the predicted working face boundary is not within all the closed areas of a certain type of factor, the predicted working face is not affected by that type of factor;

[0015] 11) Take the average value H of the elevation of the coal seam floor contour within the working face avg , and combine it with the ground elevation H0 to calculate the burial depth H of this working face: H = H0 - H avg ;

[0016] 12) In the small fault layer of the mine CAD drawing, use the ray method to determine which small faults are within the working face range. When the number of small faults within the working face range is 1 - 2, the small fault factor value is taken as "1 - 2"; when the number of small faults within the working face range is 3, the small fault factor value is taken as "3"; when the number of small faults within the working face range is greater than or equal to 4, the small fault factor value is taken as "≥4";

[0017] 13) In the fold layer of the mine CAD drawing, use the ray method to determine all the contour lines passing through the working face. For each contour line, calculate the fold ratio of each point from its starting point to the end point to another point about 100 meters away from this point in sequence, and take the maximum value of the fold ratios of all contour lines as the fold ratio of the predicted working face; when the maximum value of the fold ratio < 2, the influencing factor value of the fold ratio of the predicted working face is " < 2"; when the maximum value of the fold ratio is 2 - 3, the influencing factor value of the fold ratio of the predicted working face is "2 - 3"; when the maximum value of the fold ratio > 3, the influencing factor value of the fold ratio of the predicted working face is " > 3";

[0018] 14) In the goaf layer of the mine CAD drawing, Using the ray method Determine whether the corner points of the working face boundary are within a certain goaf closed area. If any corner point is within a certain goaf closed area, calculate the idle years of this goaf according to the marked years in this goaf. If the idle years are 1 year, the goaf factor value corresponding to this predicted working face is "1 year"; if the idle years are 2 years, the goaf factor value corresponding to this predicted working face is "2 years"; if the idle years are 3 - 5 years, the goaf factor value corresponding to this predicted working face is "3 - 5 years"; if the idle years are > 5 years, the goaf factor value corresponding to this predicted working face is " > 5 years".

[0019] Compared with the prior art, the present invention has the following beneficial effects: The present invention is simple to operate, realizes the standardization and intellectualization of the identification of multiple factors of mine gas emission, and improves the prediction accuracy; The present invention changes the existing prediction method of gas emission that subjectively determines the range of each factor manually, which is conducive to the coal mine management to timely master the gas emission information of the excavation and working faces, provides decision-making support for gas disaster prevention and control and the determination of mine ventilation air volume, and improves the gas prevention and control ability of the mine and the high efficiency and energy conservation of the mine ventilation system. Brief Description of the Drawings

[0020] Figure 1 is the operation flow chart of the present invention.

[0021] Figure 2 is the zoning map of the influence range of large faults in the embodiment of the present invention.

[0022] Figure 3 is the zoning map of the influence range of coal seam thickness in the embodiment of the present invention.

[0023] Figure 4 is the zoning map of the influence range of coal seam dip angle in the embodiment of the present invention.

[0024] Figure 5 is the equivalent lithology zoning map in the embodiment of the present invention.

[0025] Figure 6 is the syncline and anticline basin zoning map in the embodiment of the present invention.

[0026] Figure 7 is the buried depth method map in the embodiment of the present invention.

[0027] Figure 8 is the small fault determination method map in the embodiment of the present invention.

[0028] Figure 9 is the gob number method map in the embodiment of the present invention. Detailed Embodiment

[0029] The present invention will be further described below with reference to the drawings and embodiments.

[0030] As Figure 1 shown, an intelligent identification method for influencing factors of gas emission in an excavation and working face includes the following steps:

[0031] 1) Establish 10 new layers in the mine CAD drawing, and the layer names are large faults, coal seam dip angle, coal seam thickness, equivalent lithology, syncline and anticline and basin, floor contour line, small faults, folds, gob annual and forecast range respectively; Prepare for the subsequent steps. Since all the 10 new layers are visible in the mine CAD drawing, the operations of the following steps can be realized.

[0032] 2) In the major fault layer of the mine CAD drawing, it is divided into three enclosed areas of <50m, 50 - 100m, and >100m by using a closed spline curve according to the distance from the intersection line of the major fault; and <50m, 50 - 100m, and >100m are respectively marked in the three enclosed areas of <50m, 50 - 100m, and >100m.

[0033] 3) In the coal seam dip angle layer of the mine CAD drawing, the area with a coal seam dip angle <15° is drawn as an enclosed area with a closed spline curve and the text "<15°" is marked in this area. The area with a coal seam dip angle of 15 - 25° is drawn as an enclosed area with a closed spline curve and the text "15 - 25°" is marked in this area. The area with a coal seam dip angle >25° is drawn as an enclosed area with a closed spline curve and the text ">25°" is marked in this area.

[0034] 4) In the coal seam thickness layer of the mine CAD drawing, the area with a coal seam thickness <2m is drawn as an enclosed area with a closed spline curve and the text "<2m" is marked in this area. The area with a coal seam thickness of 2 - 4m is drawn as an enclosed area with a closed spline curve and the text "2 - 4m" is marked in this area. The area with a coal seam thickness >4m is drawn as an enclosed area with a closed spline curve and the text ">4m" is marked in this area.

[0035] 5) In the equivalent lithology layer of the mine CAD drawing, according to different equivalent lithologies, the mine CAD drawing is divided into seven enclosed areas of silt, fine sand, medium - fine, medium sand, coarse sand, clay, and thick mud by using a closed spline curve; and the text "silt", "fine sand", "medium - fine", "medium sand", "coarse sand", "clay", and "thick mud" are respectively marked in the corresponding enclosed areas.

[0036] 6) In the syncline - anticline basin zoning layer of the mine CAD drawing, all points with the shortest distance to the syncline - anticline axis = 100m are connected by a closed spline curve to form an enclosed area, and the text "<100m" is marked in the enclosed area. All points with the shortest distance to the syncline - anticline axis satisfying = 200m are connected by a closed spline curve to form a closed area, and the text "100 - 200m" is marked in the closed area where the shortest distance to the syncline - anticline axis is between 100 - 200m. The text ">200m" is marked in the closed area where the shortest distance to the syncline - anticline axis >200m; the basin boundary is drawn with a closed spline curve, and the text "inside the basin" is marked in the enclosed area;

[0037] 7) In the coal seam floor contour line layer of the mine CAD drawing, the elevation of each floor contour line is marked near its endpoints.

[0038] 8) In the goaf layer of the mine CAD drawing, the goaf ranges of different years are all represented by enclosed areas, and each area is marked with the year.

[0039] 9) In the prediction range layer of the mine CAD drawing, draw a rectangular closed area representing the boundary of the mining and excavation working face.

[0040] 10) Use the ray method to sequentially determine the relative position relationship between the corner points of the mining and excavation working face boundary and the closed areas in the major fault, coal seam dip angle, coal seam thickness, equivalent lithology, syncline and anticline basin maps. When any corner point of the predicted mining and excavation working face boundary is within a certain closed area, the predicted mining and excavation working face is affected by the factor corresponding to this closed area, and the factor value is the specific value marked in this closed area; if any corner point of the predicted mining and excavation working face boundary is not within all the closed areas of a certain type of factor, the predicted mining and excavation working face is not affected by this type of factor.

[0041] 11) Take the average value H of the elevation of the coal seam floor contour line within the mining and excavation working face avg , and combine it with the ground elevation H0 to calculate the buried depth H of this mining and excavation working face: H = H0 - H avg .

[0042] 12) In the small fault layer of the mine CAD drawing, use the ray method to determine which small faults are within the mining and excavation working face. When the number of small faults within the mining and excavation working face is 1 - 2, the small fault factor value is taken as "1 - 2"; when the number of small faults within the mining and excavation working face is 3, the small fault factor value is taken as "3"; when the number of small faults within the mining and excavation working face is greater than or equal to 4, the small fault factor value is taken as "≥4".

[0043] 13) In the fold layer of the mine CAD drawing, use the ray method to determine all the contour lines passing through the mining and excavation working face. For each contour line, calculate the fold ratio of each point from its starting point to the end point and another point about 100 meters away from this point in sequence. Take the maximum value of the fold ratios of all contour lines as the fold ratio of this predicted mining and excavation working face; when the maximum value of the fold ratio < 2, the fold ratio influencing factor value is taken as "<2"; when the maximum value of the fold ratio is 2 - 3, the fold ratio influencing factor value is taken as "2 - 3"; when the maximum value of the fold ratio > 3, the fold ratio influencing factor value is taken as ">3".

[0044] 14) In the goaf layer of the mine CAD drawing, Using the ray methodDetermine whether the boundary corner points of the mining face are within the closed area of a goaf. If any corner point is within the closed area of a goaf, calculate the idle years of the goaf according to the marked age in the goaf. If the idle years are 1 year, the goaf factor value corresponding to the forecast working face is "1 year"; if the idle years are 2 years, the goaf factor value corresponding to the forecast working face is "2 years"; if the idle years are 3 - 5 years, the goaf factor value corresponding to the forecast working face is "3 - 5 years"; if the idle years are >5 years, the goaf factor value corresponding to the forecast working face is ">5 years". Embodiment

[0045] The present invention takes a certain coal mine in Hebei as an example. Generally, the mine is a single - inclined structure with an approximate east - west direction and an "S" - shaped north - dipping angle. Tensional faults and secondary folds are particularly developed. The change in the direction of the strata within the mine field is also very large. The direction in the eastern section is south - northeast, and the dip angle becomes steeper, generally ranging from 25° to 55°, locally up to 70° to 80°, and even vertical; while the direction in the western section is nearly east - west, and the dip angle is about 10° to 15°. There are 268 faults with a throw greater than 5m found in this mine, including 261 normal faults and 7 reverse faults. Small structures in this mine are particularly developed. Through production disclosure, a total of 799 faults with a throw less than 5m have been found.

[0046] The following combines the drawings and embodiments to detail the specific implementation manner, features, and effects of an intelligent identification method for influencing factors of gas emission amount in the mining face proposed according to the present invention as follows.

[0047] 1. As Figure 2 shown, the boundary corner point 1 of the mining face is within 100 meters of the major fault. According to corner point 1, the influence factor value of the major fault for the forecast mining face is "100 meters from the major fault".

[0048] 2. As Figure 3 shown, the boundary corner point 1 of the mining face is within the range of coal thickness >4 meters. According to corner point 1, the influence factor value of the coal thickness for the forecast mining face is ">4 meters".

[0049] 3. As Figure 4 shown, the boundary corner point 1 of the mining face is within the area where the coal seam dip angle is 15 - 25 degrees. According to corner point 1, the influence category of the coal seam dip angle for the forecast mining face is "15 - 25 degrees".

[0050] 4. As Figure 5 shown, the boundary corner point 1 of the mining face is within the range of medium - fine sandstone of equivalent lithology. According to corner point 1, the equivalent lithology of the forecast mining face is "medium - fine sandstone".

[0051] 5. As Figure 6As shown in the figure, the boundary corner point 1 of the mining face is not within the closed area of the syncline. According to corner point 1, it is predicted that the mining face is not affected by the syncline.

[0052] 6. As Figure 7 shown in the figure, the coal seam floor contour line passed by the mining face is the contour line with an elevation of -450. A straight line is drawn through two points A and B on this contour line and extended to the vicinity of point C. A perpendicular line to the straight line passing through points A and B is drawn from point C. The length of line CE is h = 19.9, and the included angle between BC and BE is α = 4°. The fold ratio corresponding to point B is h / α = 5. The above calculations are repeated for all points on this contour line within the predicted mining face range, and the maximum value among all fold ratios is taken as the fold ratio of the predicted mining face.

[0053] The coal seam floor contour line passed by the mining face is the contour line with an elevation of -450, and the ground elevation is 0. Therefore, the predicted depth of the mining face is 450 meters, and the corresponding depth range is "≤500m".

[0054] 7. As Figure 8 shown in the figure, there is no small fault mark in the mining face, and the mining face is not affected by small faults.

[0055] 8. As Figure 9 shown in the figure, the boundary corner point 1 of the mining face is within the goaf area of 9 years, and the goaf factor value of the predicted mining face is ">5 years".

Claims

1. An intelligent identification method for influencing factors of gas emission volume in the mining face, comprising the following steps: 1) Establish 10 new layers in the mine CAD drawing, and the layer names are major faults, coal seam dip angle, coal seam thickness, equivalent lithology, syncline and anticline and basin, floor contour line, minor faults, folds, goaf years and prediction range respectively; 2) In the major fault layer of the mine CAD drawing, divide it into three closed areas of <50m, 50 - 100m, and >100m with closed spline curves according to the distance from the intersection line of major faults; and mark <50m, 50 - 100m, and >100m respectively in the three closed areas of <50m, 50 - 100m, and >100m; 3) In the coal seam dip angle layer of the mine CAD drawing, draw a closed area with a closed spline curve for the area where the coal seam dip angle < 15° and mark the text "<15°" in this area, draw a closed area with a closed spline curve for the area where the coal seam dip angle is 15 - 25° and mark the text "15 - 25°" in this area, draw a closed area with a closed spline curve for the area where the coal seam dip angle > 25° and mark the text ">25°" in this area; 4) In the coal seam thickness layer of the mine CAD drawing, draw a closed area with a closed spline curve for the area where the coal seam thickness < 2m and mark the text "<2m" in this area, draw a closed area with a closed spline curve for the area where the coal seam thickness is 2 - 4m and mark the text "2 - 4m" in this area, draw a closed area with a closed spline curve for the area where the coal seam thickness > 4m and mark the text ">4m" in this area; 5) In the equivalent lithology layer of the mine CAD drawing, divide the mine CAD drawing into seven closed areas of silt, fine sand, medium - fine, medium sand, coarse sand, clay, and thick mud with closed spline curves according to different equivalent lithologies; and mark the text "silt", "fine sand", "medium - fine", "medium sand", "coarse sand", "clay", and "thick mud" respectively in the corresponding closed areas; 6) In the syncline and anticline and basin layer of the mine CAD drawing, connect all points with the shortest distance to the syncline axis = 100m with a closed spline curve to form a closed area, and mark the text "<100m" in the closed area, connect all points with the shortest distance to the syncline axis satisfying = 200m with a closed spline curve to form a closed area, and mark the text "100 - 200m" in the closed area where the shortest distance to the syncline axis is between 100 - 200m, mark the text ">200m" in the closed area where the shortest distance to the syncline axis > 200m; draw the basin boundary with a closed spline curve and mark the text "inside the basin" in the closed area; 7) In the coal seam floor contour line layer of the mine CAD drawing, mark the elevation of each floor contour line near its endpoints; 8) In the goaf layer of the mine CAD drawing, the goaf ranges of different years are all represented by closed areas, and each area is marked with the year; 9) In the prediction range layer of the mine CAD drawing, draw a rectangular closed area representing the boundary of the mining face; 10) Use the ray method to sequentially determine the relative positional relationships between the corner points of the mining face boundary and the major faults, coal seam dip angle, coal seam thickness, equivalent lithology, syncline and anticline, and each closed area in the basin strata. When any corner point of the predicted mining face boundary is within a certain closed area, the predicted mining face is affected by the factor corresponding to the closed area, and the factor value is the specific value marked in the closed area; if any corner point of the predicted mining face boundary is not within all the closed areas of a certain type of factor, the predicted mining face is not affected by that type of factor; 11) Take the average value H of the elevation of the coal seam floor contour line within the working face of coal mining avg , and calculate the depth H of the working face of coal mining by combining with the ground elevation H0, where H = H0 - H avg ; 12) In the small fault layer of the mine CAD drawing, use the ray method to determine which small faults are within the mining face range. When the number of small faults within the mining face range is 1 - 2, the small fault factor value is taken as "1 - 2"; when the number of small faults within the mining face range is 3, the small fault factor value is taken as "3"; when the number of small faults within the mining face range is greater than or equal to 4, the small fault factor value is taken as "≥4"; 13) In the fold layer of the mine CAD drawing, use the ray method to determine all the contour lines passing through the mining face. For each contour line, calculate the fold ratio of each point and another point 100 meters away from this point in sequence from its starting point to the ending point, and take the maximum value of the fold ratios of all the contour lines as the fold ratio of the predicted mining face; when the maximum value of the fold ratio < 2, the fold ratio influencing factor value is taken as "<2"; when the maximum value of the fold ratio is 2 - 3, the fold ratio influencing factor value is taken as "2 - 3"; when the maximum value of the fold ratio > 3, the fold ratio influencing factor value is taken as ">3"; 14) In the goaf layer of the mine CAD drawing, use the ray method to determine whether the corner points of the mining face boundary are within a certain goaf closed area. If any corner point is within a certain goaf closed area, calculate the idle years of the goaf according to the marked years in the goaf. If the idle years are 1 year, the goaf factor value corresponding to the predicted working face is "1 year"; if the idle years are 2 years, the goaf factor value corresponding to the predicted working face is "2 years"; if the idle years are 3 - 5 years, the goaf factor value corresponding to the predicted working face is "3 - 5 years"; if the idle years are > 5 years, the goaf factor value corresponding to the predicted working face is ">5 years".

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