Structure and method for underground gas overrun control

Abstract

The invention discloses a structure and method for underground gas overrun treatment, and relates to the field of mine gas treatment. The at least two first drill holes obliquely extend upwards from a first drill hole arrangement area of the roadway, and the vertical distances between the tail ends of the two first drill holes and the first drill hole arrangement area are the first height and the second height respectively; the second drill hole extends in the axial direction of the first drill hole from the first drill hole arrangement area, the second drill hole and the first drill hole are coaxial, and the inner diameter of the second drill hole is larger than that of the first drill hole; the pipeline sequentially penetrates through the second drill hole and the first drill hole, the tail end of the pipeline extends to the first height position or the second height position, the head end of the pipeline is externally connected with an air extractor, and an air inlet hole is formed in the side wall of the pipeline; the plugging piece is fixedly arranged in the second drill hole and can plug the second drill hole, and the head end of the pipeline penetrates through the plugging piece. According to the structure and method for underground gas overrun control, gas accumulation overrun of the corner on the working face can be avoided.

Description

Technical Field

[0001] The invention relates to the technical field of mine gas control, and in particular to a structure and method for controlling excessive gas in a mine. Background Art

[0002] Gas disasters are one of the important factors that affect the normal production of mines. During the mining process of the working face, in addition to the basic gas outflow of the coal seam, the roof collapse causes the pressure relief and permeability increase of the adjacent layer, resulting in the connection between the mining area and the adjacent layer, causing the gas to flow into the goaf. Affected by the normal ventilation of the coal mining working face, a negative pressure is formed between the working face and the goaf. Due to the pressure difference, gas flows into the working face from the adjacent layer and the goaf. At the corner of the working face, the top coal is in a suspended state, gas accumulates, resulting in gas exceeding the limit, affecting the normal production of the working face.

[0003] At present, the methods for dealing with gas flowing from the goaf to the working face mainly include low-level drilling, buried pipe extraction, gas extraction from adjacent layers, etc., which have certain defects in the negative pressure gas flow. Some mines adopt the layout of multiple lanes, set up gas extraction lanes, and extract gas from the goaf after sealing. This method consumes a lot of resources and requires the setting of connecting lanes. During the mining process, there are certain difficulties in the support and sealing of the connecting lanes. There is no good solution for the gas accumulation in the upper corner. Summary of the invention

[0004] The purpose of the present invention is to provide a structure and method for controlling excessive gas in underground mines, so as to solve the problems existing in the above-mentioned prior art and avoid excessive gas accumulation in the corners of the working face.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a structure for controlling excessive gas in a mine, comprising:

[0007] First boreholes, at least two of which extend obliquely upward from a first borehole arrangement area of ​​the tunnel, and vertical distances between ends of the two first boreholes and the first borehole arrangement area are a first height and a second height, respectively;

[0008] a second borehole extending from the first borehole arrangement area along the axial direction of the first borehole, the second borehole being coaxial with the first borehole, and an inner diameter of the second borehole being larger than an inner diameter of the first borehole;

[0009] A pipeline passes through the second borehole and the first borehole in sequence, the end of the pipeline extends to the first height or the second height, the head end of the pipeline is externally connected to an air extraction device, and an air inlet hole is opened on the side wall of the pipeline;

[0010] A plugging piece is fixedly disposed in the second borehole and can plug the second borehole, and the first end of the pipeline passes through the plugging piece.

[0011] Preferably, the first height is the vertical distance between the collapse zone above the tunnel and the first drilling arrangement area, and the second height is the vertical distance between the fracture zone above the tunnel and the first drilling arrangement area.

[0012] Preferably, the end of the second borehole extends axially along the first borehole to a first length, and the first length is the axial length from the head end of the second borehole to the position of the hard rock area of ​​the tunnel.

[0013] Preferably, the sealing member comprises a first sealing layer and a second sealing layer, the axial length of the first sealing layer is a first sealing length, the axial length of the second sealing layer is a second sealing length; the sum of the first sealing length and the second sealing length is less than the first length.

[0014] Preferably, the first blocking layer is made of foamed polymer material, and the second blocking layer is made of quick-setting cement material.

[0015] Preferably, the pipeline includes a coaxially arranged support tube and an air intake pipe, the support tube is fixed in the first drill hole, the air intake pipe is passed through the support tube, a plurality of anti-collapse holes are opened on the support tube, and a plurality of the air intake holes are opened on the air intake pipe; the head end of the air intake pipe passes through the blocking member.

[0016] Preferably, a horizontal distance between the first drilling arrangement area and the working surface is a first spacing.

[0017] Preferably, a second drilling arrangement area is provided at one end of the first drilling arrangement area away from the working surface, and the horizontal distance between the second drilling arrangement area and the first drilling arrangement area is a second spacing; the second drilling arrangement area is provided with a first drill hole, a second drill hole, a pipeline and a sealing piece with the same structure as the first drilling arrangement area.

[0018] Preferably, the ratio of the second spacing to the first spacing is 0.2:1 to 0.5:1.

[0019] The present invention also provides a method for controlling excessive gas in a mine, comprising the following steps:

[0020] Setting a first drilling site at a first borehole arrangement area, and drilling a first borehole and a second borehole;

[0021] The pipeline is penetrated axially from the first end of the second borehole, and a plugging member is arranged in the second borehole;

[0022] Roof cracks and subsidence appear in the goaf and upper corners, and gas in the goaf and upper corners diffuses along the cracks to the first and second heights. The exhaust device is started to extract the diffused gas through the first borehole and the corresponding pipeline.

[0023] Compared with the prior art, the present invention has achieved the following technical effects:

[0024] In the present invention, at least two first boreholes are arranged in different layers, and the first boreholes in different layers can effectively ensure the extraction of gas. The plugging piece can ensure that when extracting gas, gas can enter the pipeline, and the extracted gas will not enter the tunnel or working surface; when the roof cracks and sinking appear in the goaf and the upper corner, the gas in the goaf and the upper corner diffuses along the cracks to the first height and the second height position, the gas extraction device is started, and the gas enters the pipeline corresponding to the first borehole, so as to realize the extraction of diffused gas and avoid the accumulation of gas in the upper corner. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 A schematic diagram of the arrangement of a structure for controlling excessive gas in a well in one or some embodiments of the present invention;

[0027] Figure 2 A schematic diagram of a pipeline for underground gas over-limit control in one or some embodiments of the present invention;

[0028] Figure 3 The present invention is a schematic diagram of the arrangement of plugging parts for underground gas excess control structure in one or some embodiments of the present invention.

[0029] In the figure: 1-support pipe; 2-air intake pipe; 3-anti-collapse hole; 4-air intake hole; 5-tunnel; 6-first drilling site; 7-working face; 8-goaf; 9-first borehole; 10-coal rock mass; 11-second borehole. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] The purpose of the present invention is to provide a structure and method for controlling excessive gas in underground mines, so as to solve the problems existing in the above-mentioned prior art and avoid excessive gas accumulation in the corners of the working face.

[0032] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] During the mining process of the working face of the mine, the roof collapse relieves pressure on the adjacent layers and increases permeability, resulting in the connection between the mining area and the adjacent layers, causing gas to gush into the goaf. Affected by the normal ventilation of the coal mining working face, negative pressure is formed between the working face and the goaf. Due to the pressure difference, gas flows into the working face from the adjacent layers and the goaf. At the corner of the working face, the top coal is suspended in the air, and gas accumulates here, resulting in gas exceeding the limit. Combined with the basic gas outburst of the coal seam, it seriously affects the normal production of the working face.

[0034] In order to solve the problem of excessive gas in the working face of a mine, an embodiment of the present invention provides a structure for controlling excessive gas in a mine, such as Figure 1 , Figure 2 , Figure 3As shown, it includes a first borehole 9, a second borehole 11, a pipeline and a plugging member, at least two first boreholes 9 extend obliquely upward from the first borehole 9 arrangement area of ​​the lane 5, and the vertical distances between the two first boreholes 9 ends and the first borehole 9 arrangement area are respectively the first height and the second height; the second borehole 11 extends from the first borehole 9 arrangement area along the axial direction of the first borehole 9, the second borehole 11 is coaxial with the first borehole 9, and the inner diameter of the second borehole 11 is larger than the inner diameter of the first borehole 9, that is, the second borehole 11 is formed by expanding the first borehole 9 at the head end of the first borehole 9; the pipeline passes through the second borehole 11 and the first borehole 9 in sequence, and the pipeline in this embodiment adopts a PVC pipeline, the end of the pipeline extends to the first height or the second height, the head end of the pipeline is externally connected to the exhaust device, and an air inlet 4 is opened on the side wall of the pipeline; the plugging member is fixedly arranged in the second borehole 11, can plug the second borehole 11, and the head end of the pipeline passes through the plugging member , the air inlet 4 is located in the first borehole 9; the sealing member of this embodiment adopts a first sealing layer and a second sealing layer, the first sealing layer is made of a foamed polymer material, and the second sealing layer is made of a quick-setting cement material; the axial length of the first sealing layer is a first closed length L1, and the axial length of the second sealing layer is a second closed length L2, L1 is determined according to the thickness of the sealing layer formed by the foamed polymer material actually used, and L2 is determined according to the thickness of the sealing layer formed by the quick-setting cement material actually used, and the specific values ​​of the two are not limited, and it is necessary to satisfy that the sum of L1 and L2 is less than the length of the second borehole, and at the same time meet the requirements of double-layer sealing; the sum of the first closed length and the second closed length is less than the first length; by setting two sealing layers, on the basis of preventing the first borehole 9 from collapsing and the gas gas from flowing to the working face 7, the gas gas at the first height or the second height above the top plate of the tunnel 5 is extracted and discharged, and the gas exceeding the limit in the tunnel 5 is further controlled.

[0035] The first height of this embodiment is the vertical distance between the collapse zone above the tunnel 5 and the area where the first borehole 9 is arranged, and the second height is the vertical distance between the fracture zone above the tunnel 5 and the area where the first borehole 9 is arranged. The end of the second borehole 11 extends axially along the first borehole 9 to a first length, and the first length is the axial length from the head end of the second borehole 11 to the position of the hard rock area of ​​the tunnel 5.

[0036] In order to make the gas extraction smoother, the pipeline of this embodiment adopts a rotatable double-layer tube structure, which includes a coaxially arranged support tube 1 and an air inlet pipe 2. The support tube 1 is fixed in the first borehole 9, and the air inlet pipe 2 is inserted into the support tube 1. A plurality of anti-collapse holes 3 are randomly opened on the support tube 1, and a plurality of air inlet holes 4 are randomly opened on the air inlet pipe 2. The anti-collapse holes 3 and the air inlet holes 4 are both located in the first borehole 9. The air inlet pipe 2 ensures the extraction of gas, and the support tube 1 prevents the collapse of the first borehole 9 and affects the extraction of gas. The purpose of the anti-collapse hole 3 is to allow the gas to enter the support tube 1 through the hole, and then enter the air inlet hole 4 through the support tube 1. The head end of the air inlet pipe 2 passes through the sealing member, and then the gas is extracted through the exhaust device connected to the head end of the air inlet pipe 2.

[0037] In one embodiment, a first distance L is provided in front of the working surface 7 of the tunnel 5. c The first drilling site 6 is arranged at a position behind the return air slot drilling arrangement area of ​​the working face 7, that is, behind the arrangement area of ​​the first drilling hole 9. For example, the first spacing L c 100-300m away from the cut hole, which is 2-4 times the height of the fracture zone; the height of the first drilling site 6 is not less than 3500mm, and the arrangement distance of the first drilling site 6 is 50000mm. At least two first drilling holes 9 are arranged in the coal rock mass 10 along the first drilling hole 9 arrangement area, wherein the first drilling hole 9 is a drilling hole extending upwardly obliquely from the first drilling hole 9 arrangement area, and the vertical distance between the end of one of the first drilling holes 9 and the position of the first drilling hole 9 arrangement area is the first height L a The vertical distance between the remaining drilling end of the first drilling hole 9 and the location of the first drilling hole 9 arrangement area is the second height L b .

[0038] In this embodiment, after the construction of the first drilling hole 9 arrangement area is completed, the distance between the first drilling hole 9 arrangement area and the second distance L d The second drilling hole 11 arrangement area and the second drilling field are arranged at the position, and the ratio of the second spacing to the first spacing is 0.2:1 to 0.5:1; the construction steps at the arrangement area of ​​the first drilling hole 9 are repeated. With the mining of the working face 7, the roof cracks and sinking appear in the goaf 8 and the upper corner, and the gas in the goaf 8 and the upper corner diffuses along the cracks to the first height and the second height position. The diffused gas is extracted through the first drilling hole 9 and the corresponding pipeline, so as to reduce the gas exceeding the limit in the goaf 8 and the upper corner.

[0039] The present invention also provides a method for controlling excessive gas in a mine, comprising the following steps:

[0040] A first drilling site 6 is set at the first borehole 9 arrangement area, and the first borehole 9 and the second borehole 11 are drilled;

[0041] The pipeline is penetrated axially from the first end of the second borehole 11, and a plugging member is arranged in the second borehole 11;

[0042] Roof cracks and subsidence appear in goaf 8 and the upper corner, and gas in goaf 8 and the upper corner diffuses along the cracks to the first height and the second height positions. The exhaust device is started to extract the diffused gas through the first borehole 9 and the corresponding pipeline, so as to reduce the excessive gas in goaf 8 and the upper corner.

[0043] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A structure for controlling excessive gas in underground mines, characterized by: include: First boreholes, at least two of which extend obliquely upward from a first borehole arrangement area of ​​the tunnel, and vertical distances between ends of the two first boreholes and the first borehole arrangement area are a first height and a second height, respectively; a second borehole extending from the first borehole arrangement area along the axial direction of the first borehole, the second borehole being coaxial with the first borehole, and an inner diameter of the second borehole being larger than an inner diameter of the first borehole; A pipeline passes through the second borehole and the first borehole in sequence, the end of the pipeline extends to the first height or the second height, the head end of the pipeline is externally connected to an air extraction device, and an air inlet hole is opened on the side wall of the pipeline; A plugging piece is fixedly disposed in the second borehole and can plug the second borehole, and the first end of the pipeline passes through the plugging piece.

2. The structure for controlling excessive gas in underground mines according to claim 1 is characterized in that: The first height is the vertical distance between the collapse zone above the tunnel and the first drilling arrangement area, and the second height is the vertical distance between the fracture zone above the tunnel and the first drilling arrangement area.

3. The structure for controlling excessive gas in underground mines according to claim 1 is characterized in that: The second borehole end extends axially along the first borehole to a first length, and the first length is an axial length from the head end of the second borehole to a position in a hard rock area of ​​the tunnel.

4. The structure for controlling excessive gas in underground mines according to claim 3 is characterized in that: The blocking member comprises a first blocking layer and a second blocking layer, wherein the axial length of the first blocking layer is a first sealing length, and the axial length of the second blocking layer is a second sealing length; the sum of the first sealing length and the second sealing length is less than the first length.

5. The structure for controlling excessive gas in underground mines according to claim 4 is characterized in that: The first blocking layer is made of foamed polymer material, and the second blocking layer is made of quick-setting cement material.

6. The structure for controlling excessive gas in underground mines according to claim 1 is characterized in that: The pipeline includes a coaxially arranged support pipe and an air intake pipe, the support pipe is fixed in the first drill hole, the air intake pipe is passed through the support pipe, a plurality of anti-collapse holes are opened on the support pipe, and a plurality of air intake holes are opened on the air intake pipe; the head end of the air intake pipe passes through the blocking member.

7. The structure for controlling excessive gas in underground mines according to claim 1 is characterized by: The horizontal distance between the first drilling arrangement area and the working surface is a first spacing.

8. The structure for controlling excessive gas in underground mines according to claim 7 is characterized in that: A second drilling arrangement area is provided at one end of the first drilling arrangement area away from the working surface, and the horizontal distance between the second drilling arrangement area and the first drilling arrangement area is a second spacing; the second drilling arrangement area is provided with a first drill hole, a second drill hole, a pipeline and a plugging piece with the same structure as the first drilling arrangement area.

9. The structure for controlling excessive gas in underground mines according to claim 8 is characterized in that: The ratio of the second spacing to the first spacing is 0.2:1 to 0.5:

1.

10. A method for controlling excessive gas in underground mines, characterized by: The steps include: Setting a first drilling site at a first borehole arrangement area, and drilling a first borehole and a second borehole; The pipeline is penetrated axially from the first end of the second borehole, and a plugging member is arranged in the second borehole; Roof cracks and subsidence appear in the goaf and upper corners, and gas in the goaf and upper corners diffuses along the cracks to the first and second heights. The exhaust device is started to extract the diffused gas through the first borehole and the corresponding pipeline.

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