Coal seam pressure relief and outburst elimination method and device

Abstract

The invention discloses a coal seam pressure relief and outburst elimination method and device, and belongs to the technical field of coal seam pressure relief and outburst elimination. According to the method, coal seam outburst elimination is achieved by cutting a coal seam through a rope saw, forming seams, relieving pressure, increasing permeability and discharging gas. The coal seam pressure relief outburst elimination device comprises a drilling machine and a rope saw machine with a rope saw, four drill holes are formed in a coal rock mass in front of a coal uncovering working face through the drilling machine, and it is ensured that the control range of the four drill holes is larger than a first control distance outside a coal uncovering roadway contour line; the minimum distance from the outer edge of the control range of the four drill holes to the contour line of the coal uncovering roadway is not smaller than a second control distance, and the rope sawing machine cuts and communicates the drill holes based on the drill holes to form a target space, the rope sawing machine firstly adopts a reverse cutting method to cut the top surface and two side surfaces of the target space through a rope saw, and then adopts a sleeve cutting method to cut the pressure-relief and permeability-increasing target space; the drilling angle is determined based on the coal seam occurrence condition. The coal seam extraction efficiency is improved, the cost is low, and the efficiency is high.

Description

Technical Field

[0001] The invention belongs to the technical field of coal seam pressure relief and outburst elimination, and in particular relates to a method and device for coal seam pressure relief and outburst elimination. Background Art

[0002] As coal mining gradually extends to deeper areas, the ground stress and gas pressure further increase, and the risk of coal and gas outburst disasters continues to increase, especially the high risk of outburst during the stone gate coal mining process, which seriously restricts the safe and efficient mining of deep coal resources. Coal and gas outburst is basically the result of the combined effects of ground stress, gas pressure and the physical properties of coal and rock.

[0003] At present, the anti-blowout measures of Shimen coal mining working face mainly include pre-extraction of gas and discharge drilling to reduce gas pressure; hydraulic measures such as hydraulic cutting and punching to relieve pressure and increase permeability of coal seams; metal skeletons, coal body solidification and other measures to improve the hardness of coal rock mass. Although the above measures have achieved the effect of eliminating coal seam blowouts, it takes a long time to drain gas through drilling, and the costs of hydraulic cutting, punching and installation of metal skeletons are relatively high.

[0004] Therefore, new coal mining and coal outburst prevention technologies are urgently needed, which can economically and efficiently solve the problem of coal and gas outburst during coal mining in mines.

[0005] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0006] In order to solve the technical problems that the existing technology has achieved the effect of eliminating coal seam outbursts, but the extraction and drainage of gas through drilling holes takes a long time, and the measures such as hydraulic cutting, punching and installation of metal frames are costly, a method and device for decompressing and eliminating coal seam outbursts is provided.

[0007] In a first aspect, the present invention provides a method for decompressing and eliminating coal seam outbursts, comprising the following steps: Use a drilling rig to configure four boreholes on the coal seam, and ensure that the control range of the four boreholes is greater than the first control distance outside the coal mining tunnel contour line, and the minimum distance from the outer edge of the control range of the four boreholes to the coal mining tunnel contour line is not less than the second control distance; the angle of the boreholes in the coal seam is determined based on the coal seam occurrence, and the coal seam occurrence includes the direction, dip, inclination and thickness of the coal seam, and the coal seam occurrence is explored by conducting geological drilling in the coal seam in the extraction tunnel; A wire saw machine with a wire saw is used to cut out a target space connected to the coal seam borehole based on the borehole in the coal seam, wherein the wire saw machine first uses a reverse cutting method to cut out the top surface and two side surfaces of the target space and then uses a sleeve cutting method to cut out the target space for pressure relief and permeability enhancement.

[0008] In some embodiments, the specific steps of cutting out the top surface and two surfaces of the target space by the reverse cutting method include: First, adjusting the angles of the corresponding two sets of wire saw positioning guides so that the central planes of the two sets of wire saw positioning guides are parallel to the plane of the target space; Then the wire saw is passed around the two wire saw positioning guide parts, and the wire saw and the two wire saw positioning guide parts are pushed into the corresponding boreholes by using the corresponding position adjustment parts, and fixed at the pre-cutting point, and the wire saw is connected to the two wire saw movement direction adjustment parts, the two wire saw tensioning parts and the wire saw machine; Then determine the reverse switching circuit; Finally, the wire saw machine is started to cut the coal seam at a uniform speed. At the same time, through the backward movement of the wire saw machine and the coordination of the wire saw tensioning part, the wire saw is kept tensioned and continuous forward cutting is achieved to complete the reverse cutting process.

[0009] In some embodiments, the reverse cutting circuit is in the following order: a rope saw machine, a group of rope saw tensioning parts, a group of rope saw movement direction adjustment parts, a group of rope saw positioning guide parts, a rock mass at one point, another rock mass at another point, another group of rope saw positioning guide parts, another group of rope saw movement direction adjustment parts, another group of rope saw tensioning parts, and a rope saw machine.

[0010] In some embodiments, before cutting, the wire saw needs to be in a pre-tensioned state by adjusting the wire saw tensioning part and the position of the wire saw machine.

[0011] In some embodiments, after the rope saw cuts beyond the coal seam, the rope saw is retracted along the original path, the rope saw is kept in a tensioned state, the rope saw machine is retracted, and the rope saw cuts out of the rock mass to the tunnel working surface, and then the speed is reduced and the rope is retracted to prepare for the next cutting.

[0012] In some embodiments, cutting out the target space for pressure relief and anti-reflection by using the sleeve cutting method includes: Step S341, winding the rope saw around the positioning guide wheel 5a, the positioning guide wheel 5b, the positioning guide wheel 5c, and the positioning guide wheel 5d at the same time, adjusting the center planes of the positioning guide wheels 5a and 5d in the boreholes aA and dD to be parallel to the side AadD, and the center planes of the positioning guide wheels 5b and 5c in the boreholes bB and cC to be parallel to the side BbcC, and keeping the rope saw taut; Step S342, using the hydraulic telescopic rod 6a, hydraulic telescopic rod 6b, hydraulic telescopic rod 6c, hydraulic telescopic rod 6d and moving the rope saw machine to slowly push the four positioning guide wheels 5a, positioning guide wheels 5b, positioning guide wheels 5c, positioning guide wheels 5d to the pre-cutting surface ABCD, so that the distal ends of the four positioning guide wheels 5a, positioning guide wheels 5b, positioning guide wheels 5c, positioning guide wheels 5d are in the same plane as the pre-cutting surface ABCD, and then contracting the hydraulic telescopic rod 6a, hydraulic telescopic rod 6b in the borehole aA and the borehole bB to withdraw the upper two positioning guide wheels 5a, positioning guide wheels 5b, and the rope operation is completed at this time; Step S343, connect the outer end of the rope saw to the rotary wheel 4d, the rotary wheel 4c, the tension wheel 3d, and the tension wheel 3c at the bottom surface DdcC and connect the rope saw machine; Step S344, determining the sleeve cutting loop, which is in the following order: rope saw machine, tension wheel 3d, rotary wheel 4d, positioning guide wheel 5d, coal rock mass at point A, coal rock mass at point B, positioning guide wheel 5c, rotary wheel 4c, tension wheel 3c, rope saw machine; Step S345, before cutting, the rope saw needs to be in a pre-tensioned state by adjusting the tension wheel 3d, the tension wheel 3c and the position of the rope saw machine to prevent the rope from falling off; Step S346, turning on the wire saw machine, cutting the coal and rock mass at a uniform speed, and continuously tightening the wire saw to achieve cutting from top to bottom by moving the wire saw machine backward and coordinating the tensioning wheels 3d and 3c; Step S347, when the rope saw cuts to the line connecting the lower ends of the two positioning guide wheels 5d and the positioning guide wheel 5c in the borehole cC and the borehole dD, the positioning guide wheels in the borehole lose their function, and the two rotary wheels 4d and the rotary wheel 4c at the exit of the borehole cC and the borehole dD serve as the positioning guide wheels; Step S348, at this time, the rope saw is retracted and still in the cutting state, the rope saw is in a tensioned state, and the rope saw machine is retracted to prevent the rope from falling off; Step S349, the rope saw cuts from the bottom surface DdcC position to the working surface of the stone gate tunnel, and decelerates and retracts the rope; Among them, the rotary wheel is the rope saw movement direction adjustment part, the tensioning wheel is the rope saw tensioning part, the positioning guide wheel is the rope saw positioning guide part, and the hydraulic telescopic rod is the position adjustment part.

[0013] In some embodiments, the method of cutting out the target space for pressure relief and anti-reflection by using the sleeve cutting method further comprises: Repeat the steps S341 to S349, and control the position of the slot cut inside the coal seam by shortening the advancing distance of the four sets of rope saw positioning guide parts, cut the coal seam multiple times from far to near, and inspect the effect of the coal seam after multiple cuttings, and highlight that the maximum expansion deformation of the unloaded coal seam in the mine is greater than 0.3%, which meets the requirements of unloading and permeability enhancement; By monitoring the subsidence Q1 of the upper boundary of the coal seam and the expansion Q2 of the lower boundary, the maximum expansion deformation rate ζ of the coal body is calculated. The determination formula is:

[0014] H represents the original thickness of the coal seam; h represents the width of the slot (the diameter of the rope saw); and n represents the number of cuts.

[0015] In a second aspect, the present invention provides a coal seam pressure relief and outburst elimination device, which is applicable to any one of the coal seam pressure relief and outburst elimination methods described in the first aspect, and the coal seam pressure relief and outburst elimination device comprises: A drilling machine is arranged before the minimum normal distance between the coal mining working face and the coal seam; the drilling machine is configured with four boreholes on the coal seam, and ensures that the control range of the four boreholes is greater than the first control distance outside the contour line of the coal mining roadway, and the minimum distance from the outer edge of the control range of the four boreholes to the contour line of the coal mining roadway is not less than the second control distance; A wire saw machine with a wire saw cuts out a target space connected to the coal seam borehole based on the borehole in the coal seam, wherein the wire saw machine first cuts out the top surface and two side surfaces of the target space of the coal seam borehole by a reverse cutting method through the wire saw and then cuts out the target space for pressure relief and permeability enhancement by a sleeve cutting method; The angle of the drilling hole in the coal seam is determined based on the occurrence of the coal seam, and the occurrence of the coal seam includes the direction, dip, inclination and thickness of the coal seam. The occurrence of the coal seam is explored by conducting geological drilling into the coal seam in the extraction lane.

[0016] In some embodiments, the wire saw machine is a diamond bead wire saw machine.

[0017] In some embodiments, the coal seam pressure relief and outburst elimination device further comprises: A wire saw traction unit, arranged on the wire saw machine and connected to the wire saw, for driving the wire saw to run along a cutting track; Four or more rope saw movement direction adjustment parts, which are arranged on the rope saw machine and connected to the rope saw, and are used to adjust the movement direction of the rope saw; More than four rope saw tensioning parts, connected to the rope saw, for adjusting the tension of the rope saw; Four or more rope saw positioning guides, connected to the rope saw, for fixing the movement track of the rope saw; A position adjustment unit is connected to the four or more rope saw tensioning units and the four or more rope saw positioning guide units to adjust the positions of the four or more rope saw tensioning units and the four or more rope saw positioning guide units; the position adjustment unit is electrically connected to the rope saw machine so that the movement of the position adjustment unit is regulated by the rope saw machine.

[0018] Compared with the prior art, the technical effects achieved by the present invention are as follows: The present invention can carry out positioning cutting of coal seams, and the rope saw slit pressure relief and permeability enhancement technology can continuously cut slits inside the coal seam with a large cutting range, and can often achieve the purpose of stress release through several cuttings, thereby realizing the purpose of large-area permeability enhancement of the coal seam; at the same time, the rope saw cutting process has a strong water carrying capacity, and this water can moisten the coal rock mass, weaken the brittleness of the coal rock mass, increase its plasticity, and reduce its elastic energy. In addition, the water brought into the coal mass during the sleeve cutting process can reduce the desorption rate of residual gas in the coal mass after the water moistens the coal mass, thereby reducing the gas expansion energy; according to the requirements of stone gate coal uncovering and burst prevention, the control range of the through-layer drilling hole is often larger than the contour line of the roadway at the coal uncovering location, so the coal seam rock mass cut by the present invention presents the shape characteristics of "large inside and small outside", and can still retain the protective effect of the safety rock pillar, providing a barrier for preventing gas burst energy; the coal seam is cut multiple times and multiple slits, and the cut coal dust is removed by adjusting the cutting direction of the rope saw and its own water carrying capacity, thereby providing conditions for the expansion and deformation of the coal seam. The invention has fast construction speed, low cost, safety and high efficiency, and solves the technical problems in the prior art that the coal seam has achieved the effect of eliminating sudden coal seams, but the extraction and drainage of gas through drilling is time-consuming, and the measures such as hydraulic cutting, punching and installation of metal frames are costly. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a working schematic diagram of a coal seam pressure relief and outburst elimination device provided in one embodiment of the present invention; Figure 2 is a schematic diagram of the operation of a coal seam pressure relief and outburst elimination device provided in one embodiment of the present invention at a first viewing angle; Figure 3 is a schematic diagram of the operation of the coal seam pressure relief and outburst elimination device provided in one embodiment of the present invention at a second viewing angle; Figure 4 is a schematic diagram of the operation of the coal seam pressure relief and outburst elimination device provided in one embodiment of the present invention at a third viewing angle; Figure 5 It is a schematic structural diagram of a support frame and its associated parts provided in one embodiment of the present invention. DETAILED DESCRIPTION

[0020] The technical solution of the present invention is described below by specific embodiments in conjunction with the accompanying drawings. It should be understood that the one or more than four steps mentioned in the present invention do not exclude the existence of other methods and steps before and after the combination step, or other methods and steps can be inserted between these explicitly mentioned steps. It should also be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. Unless otherwise specified, the numbering of each method step is only for the purpose of identifying each method step, and is not intended to limit the order of arrangement of each method or to define the scope of implementation of the present invention. Changes or adjustments in their relative relationships can also be regarded as the scope of implementation of the present invention without substantial changes in the technical content.

[0021] The sources of the raw materials and instruments used in the examples are not particularly limited and can be purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0022] Example: The present invention provides a method and device for decompressing and eliminating coal seam outbursts. The present invention has fast construction speed, low cost, safety and high efficiency, and solves the technical problems in the prior art that the coal seam outbursts are eliminated, but the extraction and drainage of gas through drilling is time-consuming, and measures such as hydraulic cutting, punching and installation of metal frames are costly.

[0023] like Figure 1-5 In some embodiments, a method for coal seam pressure relief and outburst elimination is provided, and a coal seam pressure relief and outburst elimination device is used during the implementation of the method for coal seam pressure relief and outburst elimination.

[0024] The coal seam pressure relief and outburst elimination device comprises: a drilling rig and a wire saw machine 1 with a wire saw. In some embodiments, the wire saw machine 1 is a diamond bead wire saw machine. During the cutting process of the diamond bead wire saw, the disturbance to the coal body is small, which can effectively reduce the damage to the coal seam rock body to ensure its integrity, maintain the good mechanical stability and bearing capacity of the coal rock body, not easy to collapse the hole, and ensure the integrity of the entire safety rock column.

[0025] In some embodiments, the coal seam pressure relief and outburst elimination device further includes: a rope saw traction unit 2, a rope saw movement direction adjustment unit, a rope saw tensioning unit, a rope saw positioning guide unit and a position adjustment unit.

[0026] The wire saw traction unit 2 is arranged on the wire saw machine 1 and connected to the wire saw 8, so as to drive the wire saw 8 to run along the cutting track; The number of the rope saw movement direction adjusting parts is more than four and all are arranged on the rope saw machine 1 and connected to the rope saw 8, so as to adjust the movement direction of the rope saw 8; in some embodiments, the rope saw 8 movement direction adjusting parts are rotating wheels and the number is four; The number of the rope saw tensioning parts is more than four and all are connected to the rope saw 8 to adjust the tightness of the rope saw 8; in some embodiments, the rope saw tensioning parts are tensioning wheels and the number is four; The number of the rope saw positioning guide parts is more than four and all are connected to the rope saw 8 to fix the movement trajectory of the rope saw 8; in some embodiments, the rope saw positioning guide parts are positioning guide wheels and the number is four; The position adjustment part is connected to the four or more rope saw tensioning parts and the four or more rope saw positioning guide parts to adjust the positions of the four or more rope saw tensioning parts and the four or more rope saw positioning guide parts; the position adjustment part is electrically connected to the rope saw machine 1, so that the action of the position adjustment part is controlled by the rope saw machine 1. In some embodiments, the position adjustment part is a hydraulic telescopic rod and the number is four; In some embodiments, the coal seam pressure relief and outburst elimination device also includes a support frame, which serves as the base of the entire coal seam pressure relief and outburst elimination device and is used to support the entire coal seam pressure relief and outburst elimination device. The support frame and the axis of the positioning guide wheel are fixed together at the front end of the hydraulic telescopic rod. The length of a single tripod of the support frame is 68 mm. The triangular leg design can maintain the stability of the hydraulic telescopic rod and the positioning guide wheel during rope saw cutting. And it is fixed on both sides of the positioning guide wheel at the same time, and the tripod on the lower inner side is removed to avoid the rope saw from being entangled when the rope is returned during the rope cutting process. Compared with conventional marble mining and cutting technology, the implementation of this method requires the design of the drilling angle and length according to the "Regulations on the Prevention and Control of Coal and Gas Outbursts". Since the drilling length is greater than the marble cutting drilling hole, the hydraulic telescopic rod is often unstable when subjected to force cutting. A triangular support frame is provided on both sides of the guide wheel to prevent the telescopic rod from shaking due to excessive force during cutting, and provide stable support for the positioning guide wheel.

[0027] The coal seam pressure relief and outburst elimination method comprises the following steps: Step S1, drilling geological holes in the coal seam in the extraction roadway to find out the coal seam occurrence, which includes the direction, dip and thickness of the coal seam, so as to determine the angle between the roadway and the direction of the coal seam and the angle between the roadway and the dip of the coal seam; Step S2, according to the "Regulations on the Prevention and Control of Coal and Gas Outbursts", a certain thickness of safety rock pillars needs to be reserved before the stone gate tunnel is excavated and does not touch the coal, and the drilling rig is set before the minimum normal distance between the coal-excavating working face and the coal seam as required; in some embodiments, the minimum normal distance is 7m; through the above-mentioned measured data, and in accordance with the drilling control area required by the "Regulations on the Prevention and Control of Coal and Gas Outbursts", the drilling rig is configured with 4 boreholes on the coal seam, and the 4 boreholes need to ensure that the control range of the boreholes is greater than the first control distance outside the contour line of the coal-excavating tunnel, and the minimum distance from the outer edge of the control range to the contour line of the tunnel (including the contour line of the pre-excavated coal-excavating tunnel) is not less than the second control distance; in some embodiments, the first control distance is 12m, and the second control distance is 5m, and the above distances are the safety distances required in the regulations on preventing outbursts; Therefore, the angles of directional drilling are determined as follows: the minimum upward elevation angle of borehole aA and the minimum deviation angle of borehole to the left; the minimum upward elevation angle of borehole bB and the minimum deviation angle of borehole to the right; the minimum downward depression angle of borehole cC and the minimum deviation angle of borehole to the left; the minimum downward depression angle of borehole dD and the minimum deviation angle of borehole to the right. Based on the angular arrangement of the boreholes, the lengths of the four boreholes are calculated on this basis, and the lengths need to ensure that the distal end of the positioning guide wheel passes through the coal seam; in some embodiments, the diameter of the borehole is set to 160 mm.

[0028] The following data are calculated based on the coal seam occurrence data and tunnel width and height detected by drilling rigs, combined with the maximum or minimum distance required for burst prevention. There are two situations: the first situation is when the coal seam dip is not in line with the tunnel direction; the second situation is when the coal seam dip is in line with the tunnel direction, it is a vertical coal seam (special case). The two situations have different general formulas.

[0029] The first case: the coal mining tunnel is usually set to an angle of 90° with the coal seam direction in consideration of cost. Here, the minimum normal distance between the working face of the coal mining tunnel and the coal seam is set to M, the first control distance is N, the second control distance is W, the coal seam inclination is α, the height and width of the tunnel are both D; the width of the coal seam is H.

[0030] Calculate the corresponding drilling angle and length as follows: Minimum upward elevation angle of borehole aA i aA for: Formula (1); Minimum deviation angle of drilling hole aA to the left e aA for: Formula (2); Length of drilling hole aA L aA for: Formula (3).

[0031] Similarly: Minimum upward elevation angle of borehole bB i bB for: Formula (4); Minimum rightward deviation angle of borehole bB e bB for: Formula (5); Length of drilling hole bB L bB for: Formula (6).

[0032] The corresponding solution is: Minimum downward angle of drilling hole cC i cC for: Formula (7).

[0033] Minimum right deviation angle of borehole cC e cC for: Formula (8); Length of drilling hole cC L cC for: Formula (9); Similarly, we can obtain: Minimum downward angle of drilling hole dD i dD for: Formula (10).

[0034] Minimum left deviation of drilling hole dD e dD for: Formula (11); Length of drilling hole dD L cC for: Formula (12); At the same time, it is also necessary to ensure that: Formula (13).

[0035] The second case, special case - vertical coal seam: Minimum upward elevation angle of borehole aA i aA , Minimum upward elevation angle of borehole bB i bB 、Minimum downward depression angle of borehole cC i cC 、Minimum downward depression angle of drilling hole dD i dD Same as the minimum left deviation angle of borehole aA e aA , Minimum deviation angle of drilling hole bB to the right e bB 、Minimum deviation angle of drilling hole cC to the left e cC , the minimum deviation angle of drilling hole dD to the right e dD The same are: Formula (14); Length of drilling hole bB L bB , length of drilling hole bB L bB , length of drilling hole cC L cC , the length of the drilling hole dD L dD Both are: Formula (15).

[0036] According to the implementation technology of this invention, the target area for drilling control covers the drilling control range in the Provisions on Prevention and Control of Coal and Gas Outbursts, so that the target range for coal seam pressure relief and permeability enhancement by rope saw cutting can meet the requirements for coal seam gas pressure relief and permeability enhancement. At the same time, the design of this inclined drilling is different from the parallel drilling design of marble mining and traditional reverse cutting method, and it can completely retain the rock mass in front of the stone gate coal uncovering working face to act as a safety rock pillar, preventing the release of the elastic energy of the coal body and the expansion energy of the gas.

[0037] In one embodiment, under the premise that the angle between the coal mining tunnel and the coal seam is set to 90°, the minimum normal distance between the coal mining tunnel working face and the coal seam is 7m, the first control distance is 12m, the second control distance is 5m, the coal seam inclination is 80°, the height and width of the tunnel are 4m; the width of the coal seam is 3m, and when the above formula is substituted to calculate the non-vertical coal seam (the first case), the angles of each drill hole are: Minimum upward elevation angle of borehole aA i aA is: 52°; Minimum deviation angle of drilling hole aA to the left e aA is: 59.4°; Length of drilling hole aA L aA Length: 32.5m; Minimum upward elevation angle of borehole bB i bB is: 52°; Minimum rightward deviation angle of borehole bB e bB is: 59.4°; Length of drilling hole bB L bB Length: 32.5m; Minimum downward angle of drilling hole cC i cC is: 50°; Minimum right deviation angle of borehole cC e cC is: 59.4°; Length of drilling hole cC L cC Length: 48.3m; Minimum downward angle of drilling hole dD i dD is: 50°; Minimum left deviation of drilling hole dD e dD is: 59.4°; Length of drilling hole dD L cC is: 48.3m.

[0038] Verify that the calculated value is: 5.79m>5m.

[0039] In another embodiment, under the premise that the angle between the coal mining tunnel and the coal seam is set to 90°, the minimum normal distance between the working face of the coal mining tunnel and the coal seam is 7m, the first control distance is 12m, the second control distance is 5m, the coal seam inclination is 90°, the height and width of the tunnel are 4m; the width of the coal seam is 3m, and the angles of each drill hole are substituted into the above formula to calculate the special case - vertical coal seam (second case): ; The length of each drill hole is: .

[0040] Step S3, using a wire saw machine with a wire saw to cut out a target space connected to the coal seam borehole based on the coal seam borehole, wherein the wire saw machine first uses the reverse cutting method to cut out the top surface AabB and two side surfaces (side surface AadD and side surface BbcC) of the target space, and then uses the sleeve cutting method to cut out the bottom surface DdcC of the target space of the coal seam borehole. In some embodiments, in the borehole space, in order to facilitate the subsequent sleeve cutting method rope operation, the diameter of the wire saw used in the reverse cutting method needs to be larger than the diameter of the wire saw used in the sleeve cutting method.

[0041] In some embodiments, the specific steps of cutting out the top surface AabB of the target space of the coal seam drilling hole by the reverse cutting method include: Step S311, adjusting the angles of the support frame 7a, support frame 7b and the positioning guide wheels 5a, positioning guide wheels 5b in the drilling holes aA and bB, so that the center planes of the positioning guide wheels 5a, positioning guide wheels 5b are in the same plane with the cutting surface AabB; Step S312, winding the rope saw 8 around the positioning guide wheel 5a, the positioning guide wheel 5b, and using the hydraulic telescopic rod 6a, the hydraulic telescopic rod 6b to push the rope saw 8 and the positioning guide wheel 5a, the positioning guide wheel 5b into the borehole aA and the borehole bB, and fix them at the pre-cutting point; Step S313, at this time, the outer end of the rope saw 8 is connected to the rotary wheel 4a, the rotary wheel 4b, the tension wheel 3a, the tension wheel 3b and the rope saw machine 1; Step S313, determining the reverse cutting loop, which is: rope saw machine 1→tensioning wheel 3b→rotating wheel 4b→positioning guide wheel 5b→point b rock mass→point a rock mass→positioning guide wheel 5a→rotating wheel 4a→tensioning wheel 3a→rope saw machine 1; Step S314: before cutting, the rope saw 8 needs to be in a pre-tensioned state by adjusting the positions of the tensioning wheel 3a, the tensioning wheel 3b and the rope saw machine 1 to prevent the rope from falling off.

[0042] Step S315, turning on the wire saw machine 1, cutting the coal seam rock mass at a uniform speed, and the wire saw machine 1 moves backward and coordinates the tensioning wheels 3a and 3b to continuously tighten the wire saw 8 to achieve forward cutting, so as to achieve the purpose of reverse cutting; Step S316, after the rope saw 8 cuts beyond the coal seam, in order to avoid the seam being damaged, the rope saw needs to be retracted along the original path to keep the rope saw in a tensioned state. The rope saw machine 1 slowly retreats, and the rope saw 8 slowly cuts out the rock mass to the working surface of the tunnel, and then slows down and retracts the rope to prepare for the next cutting.

[0043] In some embodiments, the specific steps of cutting out the side surface AadD of the target space of the coal seam drilling hole by the reverse cutting method include: Step S321, adjusting the angles of the support frame 7a, support frame 7d and the positioning guide wheel 5a, positioning guide wheel 5d in the drilling hole aA, drilling hole dD, so that the center plane of the positioning guide wheel 5a, positioning guide wheel 5d is in the same plane with the cutting surface AadD; Step S322, winding the rope saw 8 around the positioning guide wheel 5a and the positioning guide wheel 5d, and using the hydraulic telescopic rod 6a and the hydraulic telescopic rod 6d to push the rope saw 8 and the positioning guide wheel 5a and the positioning guide wheel 5d into the borehole aA and the borehole dD, and fix them at the pre-cutting point; Step S323, at this time, the outer end of the rope saw is connected to the rotary wheel 4a, the rotary wheel 4d, the tension wheel 3a, the tension wheel 3d and the rope saw machine 1; Step S323, determining the reverse cutting loop, which is: rope saw machine 1→tensioning wheel 3a→rotating wheel 4a→positioning guide wheel 5a→point a rock mass→point d rock mass→positioning guide wheel 5d→rotating wheel 4d→tensioning wheel 3d→rope saw machine 1; Step S324: before cutting, the rope saw is put in a pre-tensioned state by adjusting the positions of the tensioning wheel 3a, the tensioning wheel 3d and the rope saw machine 1 to prevent the rope from coming off.

[0044] Step S325, turning on the wire saw machine 1, cutting the coal seam rock mass at a uniform speed, and continuously tightening the wire saw 8 to achieve forward cutting by moving the wire saw machine 1 backward and coordinating the tensioning wheels 3a and 3d, so as to achieve the purpose of reverse cutting; Step S326, after the rope saw 8 cuts through the coal seam, in order to avoid the seam being damaged, the rope saw needs to be retracted along the original path to keep the rope saw in a tensioned state. The rope saw machine 1 slowly retreats, and the rope saw 8 slowly cuts out the rock mass to the working surface of the tunnel, and then slows down and retracts the rope to prepare for the next cutting.

[0045] In some embodiments, the specific steps of cutting out the side surface BbcC of the target space of the coal seam drilling hole by the reverse cutting method include: Step S331, adjusting the angles of the support frame 7b, support frame 7c and the positioning guide wheel 5b, positioning guide wheel 5c in the borehole bB, borehole cC, so that the center plane of the positioning guide wheel 5b, positioning guide wheel 5c is in the same plane with the cutting surface BbcC; Step S332, winding the rope saw 8 around the positioning guide wheel 5b and the positioning guide wheel 5c, and using the hydraulic telescopic rod 6b and the hydraulic telescopic rod 6c to push the rope saw 8 and the positioning guide wheel 5b and the positioning guide wheel 5c into the borehole bB and the borehole cC, and fix them at the pre-cutting point; Step S333, at this time, the outer end of the rope saw is connected to the rotary wheel 4b, the rotary wheel 4c, the tension wheel 3b, the tension wheel 3c and the rope saw machine 1; Step S333, determining the reverse cutting loop, which is: rope saw machine 1→tensioning wheel 3b→rotating wheel 4b→positioning guide wheel 5b→rock mass at point b→rock mass at point c→positioning guide wheel 5c→rotating wheel 4c→tensioning wheel 3c→rope saw machine 1; Step S334, before cutting, the rope saw needs to be in a pre-tensioned state by adjusting the positions of the tension wheel 3b, the tension wheel 3c and the rope saw machine 1 to prevent the rope from falling off; Step S335, turning on the wire saw machine 1, cutting the coal seam rock mass at a uniform speed, and by moving the wire saw machine 1 backward and coordinating the tensioning wheels 3b and 3c to continuously tighten the wire saw 8 to achieve forward cutting, so as to achieve the purpose of reverse cutting; Step S336, after the rope saw 8 cuts beyond the coal seam, in order to avoid the seam being damaged, the rope saw needs to be retracted along the original path to keep the rope saw in a tensioned state. The rope saw machine 1 slowly retreats, slowly cuts the rope saw out of the rock mass to the working surface of the tunnel, slows down and retracts the rope to prepare for the next cutting.

[0046] During the reverse cutting process, it is necessary to install a water inlet device at the rope feed end. When performing side cutting, the upper drill hole needs to be adjusted to the rope feed end to utilize the water's own gravity, increase the rope saw's water-carrying capacity, discharge the coal and rock cuttings cut by the rope saw, and moisten the coal seam rock mass.

[0047] Install local ventilators in the tunnels to enhance ventilation, and install a remote gas monitoring system at the working face to monitor the gas concentration of the working face in real time. If the gas concentration is too high, the speed of the rope saw can be adjusted remotely at any time to reduce the cutting speed in order to control the gas concentration and prevent the gas from exceeding the limit.

[0048] In some embodiments, based on the above-mentioned reverse cutting of the top surface AabB, the side surface AadD, and the side surface BbcC slot space, the specific steps of cutting out the target space ABCD for coal seam pressure relief and permeability enhancement by using the sleeve cutting method include: Step S341, the rope saw 8 is wound around the positioning guide wheel 5a, the positioning guide wheel 5b, the positioning guide wheel 5c, and the positioning guide wheel 5d at the same time, and the center planes of the positioning guide wheels 5a and 5d in the boreholes aA and dD are adjusted to be parallel to the side AadD, and the center planes of the positioning guide wheels 5b and 5c in the boreholes bB and cC are adjusted to be parallel to the side BbcC, and the rope saw is kept taut. At this time, the center planes of the positioning guide wheels 5a and 5b in the boreholes aA and bB are adjusted to be parallel to the side AadD and the side BbcC respectively, which not only plays a positioning role for the rope saw cutting, but also cooperates with the removed inner support frame tripod legs to avoid the triangular legs of the support frame 7a and 7b from intersecting and hanging with the rope saw 8 when the hydraulic telescopic rods 6a and 6b are retracted, thereby affecting the cutting position; and also avoids the triangular legs of the support frame 7c and 7d from hanging on the rope saw 8 when the rope saw cuts out after the rope saw sleeve cutting is completed.

[0049] Step S342, using the hydraulic telescopic rod 6a, hydraulic telescopic rod 6b, hydraulic telescopic rod 6c, hydraulic telescopic rod 6d and moving the rope saw machine 1 to slowly push the four positioning guide wheels 5a, positioning guide wheels 5b, positioning guide wheels 5c, positioning guide wheels 5d to the pre-cutting surface ABCD, so that the distal ends of the four positioning guide wheels 5a, positioning guide wheels 5b, positioning guide wheels 5c, positioning guide wheels 5d are in the same plane as the pre-cutting surface ABCD, and then contracting the hydraulic telescopic rod 6a, hydraulic telescopic rod 6b in the borehole aA and the borehole bB to withdraw the upper two positioning guide wheels 5a, positioning guide wheels 5b, and the rope operation is completed at this time; Step S343, the outer end of the rope saw 8 is connected to the rotary wheel 4d, the rotary wheel 4c, the tension wheel 3d, and the tension wheel 3c at the bottom surface DdcC and connected to the rope saw machine 1; Step S344, determine the sleeve cutting loop, which is: rope saw machine 1→tensioning wheel 3d→rotating wheel 4d→positioning guide wheel 5d→coal rock mass at point A→coal rock mass at point B→positioning guide wheel 5c→rotating wheel 4c→tensioning wheel 3c→rope saw machine 1.

[0050] Step S345, before cutting, the rope saw 8 needs to be in a pre-tensioned state by adjusting the tension wheel 3d, the tension wheel 3c and the position of the rope saw machine 1 to prevent the rope from coming off; Step S346, turning on the wire saw machine 1, cutting the coal and rock mass at a uniform speed, and continuously tightening the wire saw 8 to achieve upward and downward cutting by moving the wire saw machine 1 backward and coordinating the tensioning wheels 3d and 3c; Step S347, when the rope saw cuts to the line connecting the lower ends of the two positioning guide wheels 5d and the positioning guide wheel 5c in the borehole cC and the borehole dD, the positioning guide wheels in the borehole lose their function, and the two rotary wheels 4d and the rotary wheel 4c at the exit of the borehole cC and the borehole dD serve as the positioning guide wheels; Step S348, at this time, the rope saw 8 is still in the cutting state after the rope is retracted, the rope saw is in the tensioned state, and the rope saw machine 1 is slowly retracted to prevent the rope from falling off; Step S349, the rope saw cuts from the bottom surface DdcC position to the working surface of the stone gate tunnel, and slows down and retracts the rope to prepare for the next cutting.

[0051] During the cutting process, it is necessary to install a water inlet device in the drill hole at the upper rope inlet end, and also install a local ventilator in the tunnel to monitor the gas concentration at the working face so as to adjust the cutting speed of the rope saw at any time, control the gas concentration and prevent the gas from exceeding the limit.

[0052] After the coal-rock mass is cut, the coal-rock mass sinks due to gravity, compressing or even closing the seams cut on the bottom surface and the seams cut by rope collection. Subsequent cutting operations need to be carried out using two side surfaces AadD, side surface BbcC and top surface AabB to facilitate rope collection.

[0053] Repeat the above-mentioned cutting steps, and control the pre-cut surface ABCD cut inside the coal seam by shortening the advancing distance of the four positioning guide wheels 5a, 5b, 5c, and 5d. Cut the coal seam multiple times from far to near, and inspect the effect of the coal seam after multiple cuttings. According to the "Regulations on Prevention and Control of Coal and Gas Outbursts", the maximum expansion deformation of the unloaded coal seam in the outburst mine is greater than 0.3%, which meets the requirements of pressure relief and permeability increase.

[0054] Therefore, the subsidence of the upper boundary of the coal seam can be monitored Q 1 and the expansion amount of the lower boundary Q 2, to calculate the maximum expansion deformation rate ζ of the coal body, the determination formula is: Formula (16); H represents the original thickness of the coal seam; h represents the width of the slot (the diameter of the rope saw); and n represents the number of cuts.

[0055] At this point, it can be considered that multiple rope saw cuttings provide sufficient space for the deformation of the coal body and the pressure relief is sufficient.

[0056] By cutting the coal seam with a diamond beaded wire saw and continuously creating seams, space is provided for the stress release of the coal seam, the channels for gas release are increased, and the exposed area of ​​the coal body is increased, which can ultimately effectively release the gas pressure and ground stress. The cutting process has a relatively small degree of damage to the coal rock body, and the cut coal rock body has irregular hexahedral characteristics. The cut coal body surface is much larger than the working surface of the excavation tunnel. This "large inside and small outside" geometric feature provides a natural barrier to prevent the energy of gas outburst.

[0057] The present invention positions and cuts the coal seam rock mass by adjusting the drilling angle and the length of the telescopic rod. The rope saw cutting and pressure relief permeability enhancement technology can continuously cut inside the coal seam with a large cutting range. It can often achieve the purpose of stress release through several cuttings, thereby realizing large-area permeability enhancement of the coal seam.

[0058] At the same time, the rope saw cutting process has a strong ability to carry water, which can moisten the coal rock mass, reduce the brittleness of the coal rock mass, increase its plasticity, and reduce its elasticity. In addition, the water brought into the coal mass during the sleeve cutting process can reduce the desorption rate of residual gas in the coal mass and reduce the gas expansion energy after the water moistens the coal mass. According to the requirements of the stone gate coal outburst prevention, the control range of the through-layer drilling hole is often larger than the contour line of the roadway at the coal outburst. Therefore, the coal seam rock mass cut by the present invention presents the shape characteristics of "large inside and small outside", and can still retain the protective effect of the safety rock column, providing a barrier to prevent gas outburst energy. The coal seam is cut multiple times and multiple seams, and the cut coal dust is removed by adjusting the cutting direction of the rope saw and its own water-carrying capacity, which provides conditions for the expansion and deformation of the coal seam. According to the requirements of the "Regulations on the Prevention and Control of Coal and Gas Outbursts", combined with the measurement of actual projects, the pressure relief and permeability enhancement effect is judged to determine the number of cutting seams. The present invention can be remotely controlled during cutting, realizing unmanned working face, fast construction speed, low cost, safety and high efficiency, and solving the technical problems in the prior art that the coal seam has achieved the effect of eliminating sudden coal seams, but the extraction and discharge of gas from drilling holes takes a long time, and the measures such as hydraulic cutting, punching and installation of metal frames are costly.

[0059] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. A method for relieving coal seam pressure and eliminating outbursts, characterized in that: The following steps are involved: Use a drilling rig to configure four boreholes on the coal seam, and ensure that the control range of the four boreholes is greater than the first control distance outside the coal mining tunnel contour line, and the minimum distance from the outer edge of the control range of the four boreholes to the coal mining tunnel contour line is not less than the second control distance; the angle of the boreholes in the coal seam is determined based on the coal seam occurrence, and the coal seam occurrence includes the direction, dip, inclination and thickness of the coal seam, and the coal seam occurrence is explored by conducting geological drilling in the coal seam in the extraction tunnel; A wire saw machine (1) with a wire saw (8) is used to cut out a target space connected to the borehole in the coal seam based on the borehole in the coal seam, wherein the wire saw machine (1) first uses a reverse cutting method to cut out the top surface and two side surfaces of the target space through the wire saw (8) and then uses a sleeve cutting method to cut out the target space for pressure relief and permeability enhancement.

2. The method for relieving coal seam pressure and eliminating outbursts according to claim 1, characterized in that: The specific steps of cutting out the top surface and two side surfaces of the target space by the reverse cutting method include: First, adjusting the angles of the corresponding two sets of wire saw positioning guides so that the central planes of the two sets of wire saw positioning guides are parallel to the plane of the target space; Then, the rope saw (8) is passed around the two sets of rope saw positioning guide parts, and the rope saw (8) and the two sets of rope saw positioning guide parts are pushed into the corresponding boreholes together using the corresponding position adjustment parts, and fixed at the pre-cutting point, and the rope saw (8) is connected to the two sets of rope saw movement direction adjustment parts, the two sets of rope saw tensioning parts and the rope saw machine (1); Then determine the reverse switching circuit; Finally, the wire saw machine (1) is started to cut the coal seam at a uniform speed. At the same time, through the backward movement of the wire saw machine (1) and the coordination of the wire saw tensioning unit, the wire saw (8) is kept tensioned and continuous forward cutting is achieved, thereby completing the reverse cutting process.

3. The method for relieving coal seam pressure and eliminating outbursts according to claim 2, characterized in that: The reverse cutting loop comprises, in order: a rope saw machine (1), a set of rope saw tensioning parts, a set of rope saw movement direction adjusting parts, a set of rope saw positioning guide parts, a rock mass at one point, another rock mass at another point, another set of rope saw positioning guide parts, another set of rope saw movement direction adjusting parts, another set of rope saw tensioning parts, and a rope saw machine (1).

4. The method for relieving coal seam pressure and eliminating outburst according to claim 3, characterized in that: Before cutting, the rope saw (8) needs to be in a pre-tensioned state by adjusting the position of the rope saw tensioning part and the rope saw machine (1).

5. The method for relieving coal seam pressure and eliminating outbursts according to claim 3, characterized in that: After the rope saw (8) has cut through the coal seam, the rope saw (8) is retracted along the original path, the rope saw (8) is kept in a tensioned state, the rope saw machine (1) is retracted, and the rope saw (8) is cut out of the rock mass to the working surface of the tunnel, and then the speed is reduced and the rope is retracted to prepare for the next cutting.

6. The method for relieving coal seam pressure and eliminating outbursts according to claim 2, characterized in that: The rope saw movement direction adjustment part is a rotary wheel, the rope saw tensioning part is a tensioning wheel, the rope saw positioning guide part is a positioning guide wheel, and the position adjustment part is a hydraulic telescopic rod; The method of cutting out the target space for pressure relief and anti-reflection by using the sleeve cutting method comprises: Step S341, winding the rope saw (8) around the positioning guide wheel (5a), the positioning guide wheel (5b), the positioning guide wheel (5c), and the positioning guide wheel (5d) at the same time, adjusting the center plane of the positioning guide wheel (5a) and the positioning guide wheel (5d) in the drill hole (aA) and the drill hole (dD) to be parallel to the side surface (AadD), and the center plane of the positioning guide wheel (5b) and the positioning guide wheel (5c) in the drill hole (bB) and the drill hole (cC) to be parallel to the side surface (BbcC), and keeping the rope saw taut; Step S342, using the hydraulic telescopic rod (6a), the hydraulic telescopic rod (6b), the hydraulic telescopic rod (6c), and the hydraulic telescopic rod (6d) and moving the rope saw machine (1) to slowly push the four positioning guide wheels (5a), the positioning guide wheel (5b), the positioning guide wheel (5c), and the positioning guide wheel (5d) to the pre-cutting surface (ABCD), so that the distal ends of the four positioning guide wheels (5a), the positioning guide wheels (5b), the positioning guide wheels (5c), and the positioning guide wheels (5d) are in the same plane as the pre-cutting surface (ABCD), and then the hydraulic telescopic rod (6a) and the hydraulic telescopic rod (6b) in the drilling hole (aA) and the drilling hole (bB) are retracted to withdraw the upper two positioning guide wheels (5a) and the positioning guide wheels (5b), and the rope-roping operation is now completed; Step S343, connecting the outer end of the rope saw (8) to the rotating wheel (4d), the rotating wheel (4c), the tensioning wheel (3d), and the tensioning wheel (3c) at the bottom surface (DdcC) and connecting the rope saw machine (1); Step S344, determining the cutting loop, which is in the following order: rope saw machine (1), tension wheel (3d), rotary wheel (4d), positioning guide wheel (5d), coal rock mass at point A, coal rock mass at point B, positioning guide wheel (5c), rotary wheel (4c), tension wheel (3c), rope saw machine (1); Step S345, before cutting, the rope saw (8) needs to be placed in a pre-tensioned state by adjusting the tension wheel (3d), the tension wheel (3c) and the rope saw machine (1) to prevent the rope from coming off; Step S346, turning on the wire saw machine (1) to cut the coal and rock mass at a uniform speed, and by moving the wire saw machine (1) backward and coordinating the tensioning wheel (3d) and the tensioning wheel (3c) to continuously tighten the wire saw (8) to achieve upward and downward cutting; Step S347, when the rope saw cuts to the line connecting the lower ends of the two positioning guide wheels (5d) and the positioning guide wheel (5c) in the drill hole (cC) and the drill hole (dD), the positioning guide wheels in the drill hole lose their function, and the two rotary wheels (4d) and the rotary wheel (4c) at the exit of the drill hole (cC) and the drill hole (dD) serve as the positioning guide wheels; Step S348, at this time, the rope saw (8) is retracted while still maintaining the cutting state, and the rope saw (8) is in a tensioned state, so that the rope saw machine (1) moves backward to prevent the rope from falling off; Step S349, the rope saw (8) cuts from the bottom surface (DdcC) to the working surface of the stone gate tunnel, and decelerates and retracts the rope.

7. The method for relieving coal seam pressure and eliminating outbursts according to claim 6, characterized in that: The method of cutting out the target space for pressure relief and anti-reflection by using the sleeve cutting method also includes: Repeat the steps S341 to S349, and control the position of the slot cut inside the coal seam by shortening the advancing distance of the four sets of rope saw positioning guide parts, cut the coal seam multiple times from far to near, and inspect the effect of the coal seam after multiple cuttings, and highlight that the maximum expansion deformation of the unloaded coal seam in the mine is greater than 0.3%, which meets the requirements of unloading and permeability enhancement; By monitoring the subsidence Q1 of the upper boundary of the coal seam and the expansion Q2 of the lower boundary, the maximum expansion deformation rate ζ of the coal body is calculated. The determination formula is: H represents the original thickness of the coal seam; h represents the width of the slot; and n represents the number of cuts.

8. A coal seam pressure relief and outburst elimination device, characterized in that: The method for relieving coal seam pressure and eliminating outbursts according to any one of claims 1 to 7, wherein the device for relieving coal seam pressure and eliminating outbursts comprises: A drilling machine is arranged before the minimum normal distance between the coal mining working face and the coal seam; the drilling machine is configured with four boreholes on the coal seam, and ensures that the control range of the four boreholes is greater than the first control distance outside the contour line of the coal mining roadway, and the minimum distance from the outer edge of the control range of the four boreholes to the contour line of the coal mining roadway is not less than the second control distance; A wire saw machine (1) with a wire saw (8) is used to cut out a target space connected to the coal seam borehole based on the borehole in the coal seam, wherein the wire saw machine (1) first uses a reverse cutting method to cut out the top surface and two side surfaces of the target space of the coal seam borehole and then uses a sleeve cutting method to cut out the target space for pressure relief and permeability enhancement; The angle of the drilling hole in the coal seam is determined based on the occurrence of the coal seam, and the occurrence of the coal seam includes the direction, dip, inclination and thickness of the coal seam. The occurrence of the coal seam is explored by conducting geological drilling into the coal seam in the extraction lane.

9. The coal seam pressure relief and outburst elimination device according to claim 8, characterized in that: The wire saw machine (1) is a diamond bead wire saw machine.

10. The coal seam pressure relief and outburst elimination device according to claim 8, characterized in that: Also includes: A wire saw traction unit (2), arranged on the wire saw machine (1) and connected to the wire saw (8), for driving the wire saw (8) to run along a cutting track; Four or more rope saw movement direction adjustment parts, which are arranged on the rope saw machine (1) and connected to the rope saw (8) to adjust the movement direction of the rope saw; Four or more rope saw tensioning parts connected to the rope saw (8) for adjusting the tightness of the rope saw (8); Four or more rope saw positioning guides, connected to the rope saw, for fixing the movement track of the rope saw; A position adjustment unit is connected to the four or more rope saw tensioning units and the four or more rope saw positioning guide units to adjust the positions of the four or more rope saw tensioning units and the four or more rope saw positioning guide units; the position adjustment unit is electrically connected to the rope saw machine (1) so that the movement of the position adjustment unit is regulated by the rope saw machine (1).

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