Monitoring method of three spontaneous combustion zones in goaf of coal mining face

Abstract

The present application discloses a monitoring method for three spontaneous combustion zones in a goaf of a coal mining face. The coal mining face comprises a goaf, a working face, a cutting eye, an air inlet chute and an air return chute. A roof roadway is provided in the roof of the coal mining face, or a bottom roadway is provided in the bottom of the coal mining face. The roof roadway or the bottom roadway is formed as a drilled roadway. The monitoring method comprises: S1: drilling a plurality of drilling channels from the drilled roadway toward the goaf, wherein the plurality of drilling terminals are all located in the goaf and are distributed in sequence at intervals in a direction parallel to the length direction of the cutting eye; S2: providing a plugging assembly and an exhaust pipe in the drilling channel; S3: periodically sampling the gas in the detection chamber by using a gas sampling device to obtain an oxygen concentration value, and stopping sampling when the oxygen concentration value is detected to be lower than a preset oxygen concentration threshold; S4: determining the distribution range of the three spontaneous combustion zones in the goaf of the coal mining face according to the corresponding change law between the oxygen concentration value obtained by detection and the working face advancement distance.

Description

Technical Field

[0001] The present application relates to the technical field of disaster prevention and control in goaf areas of coal mines, and in particular to a method for monitoring three spontaneous combustion zones in goaf areas of coal mining working faces. Background Art

[0002] With the popularization of high-yield and efficient comprehensive mechanized top coal caving technology, the efficiency of coal mining has been greatly improved. Limited by the mining process, a large amount of floating coal will inevitably be left in the goaf during the mining process, and the distribution is uneven. Under the condition of long-term air leakage and oxygen supply, oxidation and spontaneous combustion are very likely to occur, which brings huge fire safety hazards to the goaf of the coal mining working face and seriously threatens the health and safety of mine workers. Therefore, it is very important to master the distribution of the "three zones" of spontaneous combustion in the goaf of the coal mining working face to guide the safe advancement speed of the working face and select reasonable goaf nitrogen injection and grouting parameters, as well as to take other timely and effective fire prevention and extinguishing measures.

[0003] There is no unified standard and basis for the division of the "three zones" in goaf areas. There are three main division methods, namely the critical oxygen concentration method, the goaf air leakage velocity method, and the goaf temperature rise rate method. The above methods all have their own advantages and disadvantages. In combination with the actual application of most mines, the critical oxygen concentration method is mostly used. This method is the most widely used division method with good effect and on-site consistency.

[0004] In the related technologies, the "three zones" measurement scheme of the goaf is carried out in the mining face, which can be mainly divided into two measurement methods: Method 1: Setting measurement points in the air inlet and return chute of the coal mining face, and taking gas samples for detection after the measurement points enter the goaf; Method 2: Setting measurement points along the conveyor at the rear of the working face, and taking gas samples for detection after the measurement points enter the goaf. After the measurement points are arranged in the above two methods, a protective casing is laid, and a bundle pipe for connecting the measurement points and the gas sampling device is set in the casing. As the working face is mined, gas samples are drawn from each measurement point at regular intervals every day for analysis, and finally the distribution of the "three zones" of spontaneous combustion in the goaf of the coal mining face is obtained according to the change range of oxygen concentration.

[0005] However, it was found on site that as the working face continued to move forward, the protective casing was easily damaged and compacted by the coal gangue that collapsed from the roof of the goaf, causing the bundle pipe to break, which in turn caused the collected sampled gas to fail to truly reflect the gas composition at the measuring point, resulting in inaccurate division of the "three zones" of spontaneous combustion in the goaf of the coal mining working face. In addition, the coal sludge formed after the working face production water, roof water and other water sources entered the goaf easily flooded or blocked the sampling point. The protective casing and bundle pipes laid in the two lanes of the working face were relatively long, occupying a lot of manpower, and there were many joints in the pipeline, which was prone to blockage and gas leakage, and the maintenance workload was large during use.

[0006] In order to overcome the above problems, the existing patent with the publication number CN115949465A discloses a method for measuring the three spontaneous combustion zones in the goaf of the fully-mechanized mining face of a spontaneous combustion mine. By arranging several ground wells above the working face to be tested, the gas extraction pump and the wellhead of the ground well are sealed and connected by a gas extraction pipeline to extract gas, and the oxygen concentration in the gas extraction pipeline is monitored. In theory, this method can be applied to the monitoring of the "three spontaneous combustion zones" in the goaf of shallow buried depth and single coal seam, but for the monitoring of the "three spontaneous combustion zones" in the goaf of coal seams with deeper buried depth, the construction of the ground well will inevitably consume a lot of time, manpower, cost, etc. Secondly, most coal mines are multi-horizontal coal seams. When extracting gas through the ground well, it is inevitable that it will be affected by the gas in other mined goafs, making it difficult to ensure the accuracy of gas collection.

[0007] The existing patent with publication number CN116398238A discloses a method for realizing three-zone division of spontaneous combustion and fire prevention and extinguishing by using large-diameter boreholes. A row of large-diameter boreholes with a diameter range of 500 to 800 mm are designed near the tunnel to penetrate the coal seam to the goaf for monitoring. By continuously advancing the borehole depth, two positions with oxygen concentrations of 18% and 7% respectively inside the goaf are found, and then the "three zones" of spontaneous combustion are divided. During the mining process of the working face, as the working face continues to advance, the oxygen concentration in the goaf is bound to be in a state of constant change. The inclination length of the working face is basically around 200m or more. The borehole advancement depth is large, and the angle of the borehole offset increases with the increase in advancement depth, which leads to a large error in the correspondence between the oxygen concentration monitoring and the measured position, thereby affecting the accuracy of the three-zone monitoring. In addition, the large-diameter drilling requirement has high requirements for underground construction, and in many cases, the conditions cannot be met for drilling construction. Summary of the invention

[0008] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the present application is to propose a monitoring method for the three spontaneous combustion zones in the goaf of a coal mining face, wherein the monitoring method for the three spontaneous combustion zones in the goaf of a coal mining face has a short drilling distance, can ensure the accuracy of the position of the gas measuring point in the goaf, and the gas extraction pipe will not be damaged by the falling coal gangue, can ensure the authenticity of the sampled gas, the number of drill holes required to be opened is small, and the division accuracy of the three spontaneous combustion zones is high.

[0009] This application also proposes another method for monitoring the three spontaneous combustion zones in the goaf of a coal mining face.

[0010] According to the monitoring method of the three spontaneous combustion zones in the goaf of a coal mining face in the first aspect of the embodiment of the present application, the coal mining face comprises a goaf, a working face, a cut eye, an air inlet chute and a return air chute, the cut eye is located between the goaf and the working face, the cut eye is suitable for arranging a working face support, the air inlet chute and the return air chute are respectively arranged at both ends of the length direction of the cut eye and are connected to each other through the cut eye, a top plate roadway is arranged in the top plate of the coal mining face, or a bottom plate roadway is arranged in the bottom plate of the coal mining face, the top plate roadway or the bottom plate roadway is formed as a drilling roadway for drilling construction, the projection of the drilling roadway in the first reference plane is located between the projection of the air inlet chute in the first reference plane and the projection of the return air chute in the first reference plane, wherein the first reference plane is a plane parallel to the length extension direction of the air inlet chute, the length extension direction of the return air chute and the length extension direction of the cut eye; the monitoring method comprises:

[0011] S1: Drilling a plurality of drilling channels from the inner wall surface of the drilling tunnel toward the goaf, the two ends of each drilling channel in the length direction are respectively a drilling start end and a drilling end end, each drilling end end is located in the goaf, each drilling start end is located on the inner wall surface of the drilling tunnel, and the plurality of drilling ends are sequentially spaced along a first direction, wherein the first direction is a direction parallel to the length extension direction of the cut eye;

[0012] S2: a plugging assembly and an exhaust pipe are arranged in the drilling channel, the plugging assembly is used to plug the open opening at the starting end of the drilling hole so as to form a sealed detection cavity in the drilling channel, one end of the exhaust pipe passes through the plugging assembly to extend into the detection cavity, and the other end of the exhaust pipe is located in the drilling tunnel and connected to a gas sampling device;

[0013] S3: During the mining process of the working face, the gas in each detection cavity is sampled periodically by using the gas sampling device, and the components of the sampled gas in each detection cavity are detected to obtain the oxygen concentration value in each detection cavity, and the oxygen concentration value of each detection cavity and the distance of the corresponding drilling terminal from the working face are recorded. As the working face is continuously mined, the oxygen concentration value of the sampled gas will decrease until the sampling is stopped when it is detected that the oxygen concentration value in the sampled gas is lower than the preset oxygen concentration threshold value;

[0014] S4: Determine the distribution range of the three spontaneous combustion zones in the goaf of the coal mining working face based on the corresponding change pattern between the oxygen concentration value in each detection chamber and the corresponding distance between the drilling terminal and the working face.

[0015] In addition, the method for monitoring the three spontaneous combustion zones in the goaf of a coal mining face according to the embodiment of the present application may also have the following additional technical features:

[0016] According to one embodiment of the present application, when the drilled tunnel is the roof tunnel, the vertical distance between the drilled tunnel and the coal mining face is greater than 15 times the mining height.

[0017] According to one embodiment of the present application, multiple drilling terminals are evenly spaced in the first direction; and / or the distance L1 between the centers of two adjacent drilling terminals in the first direction ranges from 40m to 70m; and / or the centers of multiple drilling terminals are located on the same straight line; and / or the distance L2 between the center of each drilling terminal and the wall of the goaf facing the cutting eye in the second direction ranges from 5m to 10m, wherein the second direction is a direction parallel to the length extension direction of the inlet chute and the length extension direction of the return air chute; and / or the length of the part of each drilling channel located in the goaf in the third direction is greater than or equal to 0.5m, wherein the third direction is a direction perpendicular to both the first direction and the second direction; and / or the axis of each drilling channel is parallel to a second reference plane, wherein the second reference plane is a plane perpendicular to the second direction.

[0018] According to one embodiment of the present application, one of the multiple drilling terminals is located in the air inlet chute of the goaf, and one of the multiple drilling terminals is located in the air return chute of the goaf.

[0019] According to one embodiment of the present application, the plugging assembly includes: a first plugging member and a second plugging member, the first plugging member and the second plugging member are arranged at intervals in the drilling channel, and the first plugging member is located on the side of the second plugging member away from the starting end of the drilling; a grouting pipe, one end of the grouting pipe passes through the second plugging member to extend into the gap between the first plugging member and the second plugging member, and the other end of the grouting pipe is located in the drilling tunnel and is suitable for connecting a grouting device; a return grouting pipe, one end of the return grouting pipe passes through the second plugging member to extend into the gap between the first plugging member and the second plugging member, and the other end of the return grouting pipe is located in the drilling tunnel, and the length of the return grouting pipe between the first plugging member and the second plugging member is greater than the length of the grouting pipe between the first plugging member and the second plugging member; a grouting filling layer, the grouting filling layer is arranged in the drilling channel and between the first plugging member and the second plugging member, and is used to fill the gap between the first plugging member and the second plugging member.

[0020] According to one embodiment of the present application, the sealing assembly also includes a slurry layer, which is arranged in the drilling channel and located on the side of the second sealing member away from the first sealing member, and the surface of the slurry layer away from the second sealing member is flush with the periphery of the open mouth at the starting end of the drilling.

[0021] According to an embodiment of the present application, an auxiliary air extraction hole is formed on the circumferential side wall of one end of the air extraction tube located in the detection cavity.

[0022] According to the monitoring method of the three spontaneous combustion zones in the goaf of a coal mining face in the second aspect of the embodiment of the present application, the coal mining face includes a goaf, a working face, a cut eye, an air inlet chute and a return air chute, the cut eye is located between the goaf and the working face, the cut eye is suitable for arranging a working face support, the air inlet chute and the return air chute are respectively arranged at both ends of the length direction of the cut eye and are connected to each other through the cut eye; a first lane is formed on the side of the air inlet chute away from the return air chute, and the length extension direction of the first lane is parallel to the length extension direction of the air inlet chute, and a second lane is formed on the side of the return air chute away from the air inlet chute, and the length extension direction of the second lane is parallel to the length extension direction of the return air chute, and the monitoring method includes:

[0023] S1: drilling a first drilling channel from the first tunnel toward the goaf, wherein two ends of the first drilling channel in the length direction are respectively a first drilling start end and a first drilling end end, the first drilling start end is located on the inner wall surface of the first tunnel, and the first drilling end end is located in the goaf,

[0024] A second drilling channel is drilled from the second tunnel toward the goaf, the two ends of the second drilling channel in the length direction are respectively a second drilling start end and a second drilling end end, the second drilling start end is located on the inner wall surface of the second tunnel, the second drilling end end is located in the goaf, and the first drilling end end and the second drilling end end are spaced apart in the goaf along the length extension direction of the cut eye;

[0025] S2: a first plugging component and a first exhaust pipe are arranged in the first drilling channel, the first plugging component is used to plug the open opening at the starting end of the first drilling hole so as to form a sealed first detection cavity in the first drilling channel, one end of the first exhaust pipe passes through the first plugging component to extend into the first detection cavity, and the other end of the first exhaust pipe is located in the first lane and connected to a first gas sampling device,

[0026] A second plugging component and a second gas extraction pipe are arranged in the second drilling channel, the second plugging component is used to plug the open opening at the starting end of the second drilling hole so as to form a sealed second detection cavity in the second drilling channel, one end of the second gas extraction pipe passes through the second plugging component to extend into the second detection cavity, and the other end of the second gas extraction pipe is located in the second laneway and connected to a second gas sampling device;

[0027] S3: During the mining process of the working face, the first gas sampling device and the second gas sampling device are used to periodically sample the gases in the first detection chamber and the second detection chamber respectively, and the components of the sampled gases in the first detection chamber and the second detection chamber are detected to obtain the oxygen concentration values ​​in the first detection chamber and the second detection chamber, and the detected oxygen concentration value of the first detection chamber and the distance from the first drilling terminal to the working face, as well as the detected oxygen concentration value of the second detection chamber and the distance from the second drilling terminal to the working face are recorded respectively. As the working face is continuously mined, the oxygen concentration value of the sampled gas will decrease until the oxygen concentration value in the sampled gas is detected to be lower than a preset oxygen concentration threshold, and sampling is stopped;

[0028] S4: Based on the corresponding change law between the oxygen concentration value in the first detection chamber and the distance between the first drilling terminal and the working face, as well as the corresponding change law between the oxygen concentration value in the second detection chamber and the distance between the second drilling terminal and the working face, the distribution range of the three spontaneous combustion zones in the goaf of the coal mining working face is determined.

[0029] In addition, the method for monitoring the three spontaneous combustion zones in the goaf of a coal mining face according to the embodiment of the present application may also have the following additional technical features:

[0030] According to one embodiment of the present application, the first drilling terminal is located in the air inlet chute of the goaf, and the second drilling terminal is located in the air return chute of the goaf.

[0031] According to one embodiment of the present application, the straight line formed by the center of the first drilling terminal and the center of the second drilling terminal is parallel to a first direction, wherein the first direction is a direction parallel to the length extension direction of the cutting eye; and / or the range of the distance D1 between the center of the first drilling terminal and the wall of the goaf facing the cutting eye in the second direction and the range of the distance D2 between the center of the second drilling terminal and the wall of the goaf facing the cutting eye in the second direction are both 5m~10m, wherein the second direction is a direction parallel to the length extension direction of the inlet chute and the length extension direction of the return air chute; and / or the length of the part of the first drilling channel located in the goaf along the third direction is greater than or equal to 0.5m, and the length of the part of the second drilling channel located in the goaf along the third direction is greater than or equal to 0.5m, wherein the third direction is a direction perpendicular to both the first direction and the second direction; and / or the axis of the first drilling channel and the axis of the second drilling channel are both parallel to a second reference plane, wherein the second reference plane is a plane perpendicular to the second direction.

[0032] Compared with the prior art, the monitoring method of the three spontaneous combustion zones in the goaf of the coal mining face of the embodiment of the present application has at least the following beneficial effects:

[0033] 1. Directional drilling is carried out into the goaf through the adjacent tunnels (which may be the roof tunnel, floor tunnel, or the first tunnel and the second tunnel) of the goaf of the coal mining face to form a drilling channel for gas sampling. This can avoid the mixing of gases from other locations into the drilling channel under conditions such as multiple coal seams, complex geological structures, and ventilation disorders, which may affect the composition of the sampled gas. The length of the drilling channel is greatly shortened, thereby greatly shortening the drilling distance, and the drilling direction will not deviate significantly, thereby ensuring the accuracy of the gas measurement point position in the goaf. In addition, drilling in adjacent tunnels can also reduce drilling costs and save drilling time, thereby improving monitoring efficiency.

[0034] 2. Drilling construction is carried out through the adjacent tunnels of the goaf of the coal mining face, which will not affect the pushing and mining work of the working face and ensure the pushing and mining efficiency.

[0035] 3. The exhaust pipe is installed in the borehole channel to avoid the risk of being damaged by the collapsed coal gangue during the mining process on the working face, and to ensure the authenticity of the sampled gas. In addition, the exhaust pipe required in the embodiment of the present application only needs to introduce the gas in the borehole channel into the adjacent tunnel and connect it to the gas sampling device. The length of the exhaust pipe only needs to ensure that it can extend from the borehole channel to the adjacent tunnel, which is much shorter than the length of the bundle pipe pre-buried in the air inlet chute and the return air chute in the related art.

[0036] 4. By arranging multiple drilling terminals in the goaf at intervals along the length extension direction of the cut eye, as the work of pushing and mining on the working face proceeds, the position of the drilling terminal in the goaf will change, the drilling terminal gradually enters the depth of the goaf, and the distance between the drilling terminal and the working face becomes farther and farther. By regularly sampling and analyzing the gas in each drilling channel, the corresponding relationship between the oxygen concentration value in the goaf gas at the location of each drilling terminal and the distance between the drilling terminal and the working face can be obtained, thereby determining the distribution range of the three spontaneous combustion zones in the goaf of the coal mining working face. That is to say, in this application, it is only necessary to drill multiple drilling channels from the adjacent tunnels toward the goaf, and the drilling terminals of the multiple drilling channels are arranged at intervals in the goaf along the length extension direction of the cut eye. By regularly sampling and analyzing the gas in each drilling channel, the distribution range of the three spontaneous combustion zones in the goaf of the coal mining working face can be obtained. In the embodiment of the present application, the number of boreholes required to be opened is small, and the accuracy of the division of the three spontaneous combustion zones is related to the gas sampling frequency in each drilling channel. During the working face mining work, the accuracy of the division of the three spontaneous combustion zones can be improved by increasing the gas sampling frequency in the drilling channel without increasing the number of drilling channels in the mining direction.

[0037] 5. When the adjacent tunnel where the drilling construction is carried out is a roof tunnel, the influence of water on the borehole can be eliminated; when the adjacent tunnel where the drilling construction is carried out is a floor tunnel (such as a bottom extraction tunnel), in addition to being used to extract gas samples, the drilling channel itself can also be used for drainage, avoiding the risk of coal sludge formed by water accumulation in the goaf flooding or blocking the sampling point; when the adjacent tunnels where the drilling construction is carried out are the first tunnel and the second tunnel mentioned above, the influence of water accumulation on the borehole can also be eliminated by arranging the drill holes at a high position.

[0038] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0040] Figure 1 It is a top view of a coal mining face according to an embodiment of the present application, in which a hole is drilled from a floor tunnel toward a goaf to form a drilling channel for gas sampling;

[0041] Figure 2 for Figure 1 A cross-sectional view of a portion of the structure of a coal mining face shown in ;

[0042] Figure 3 for Figure 1Schematic diagram of the coordination between the drilling channel of the coal mining face, the plugging assembly and the exhaust pipe shown in FIG.

[0043] Figure 4 It is a top view of a coal mining face according to an embodiment of the present application, in which holes are drilled from a first tunnel and a second tunnel toward a goaf to form a first drilling channel and a second drilling channel for gas sampling;

[0044] Figure 5 It is a schematic diagram of the “three zones” division of the goaf area of ​​a coal mining face according to an embodiment of the present application;

[0045] Figure 6 It is a trend chart of the change between the oxygen concentration in each drilling channel and the distance between the drilling terminal and the working surface.

[0046] Reference numerals:

[0047] Coal mining face 100; goaf 10; working face 20; cut eye 30; air inlet chute 40; return air chute 50; working face support 60; heat dissipation belt 10a; oxidation belt 10b; suffocation belt 10c; drilling channel 70; drilling start end 71; open mouth 711; drilling terminal 72; detection chamber 73; first drilling channel 70a; first drilling start end 70a1; first drilling terminal 70a2; second drilling channel 70b; first The second drilling starting end 70b1; the second drilling terminal 70b2; the plugging assembly 80; the first plugging part 81; the second plugging part 82; the grouting pipe 83; the return grouting pipe 84; the grouting filling layer 85; the slurry layer 86; the exhaust pipe 90; the exhaust hole 91; the auxiliary exhaust hole 92; the bottom plate tunnel 200; the gas sampling device 201; the first tunnel 300; the first gas sampling device 301; the second tunnel 400; the second gas sampling device 401. DETAILED DESCRIPTION

[0048] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0049] See below Figure 1-Figure 3 as well as Figure 5 A method for monitoring three spontaneous combustion zones in the goaf 10 of a coal mining face 100 according to an embodiment of the first aspect of the present application is described.

[0050] See also Figure 1The coal mining working face 100 includes a goaf 10, a working face 20, a cutting eye 30, an air inlet chute 40 and a return air chute 50. The cutting eye 30 is located between the goaf 10 and the working face 20. The cutting eye 30 is suitable for arranging a working face support 60 and coal mining equipment. The air inlet chute 40 and the return air chute 50 are respectively arranged at both ends of the cutting eye 30 in the length direction and are connected to each other through the cutting eye 30, thereby forming an air inlet and return system.

[0051] It is understandable that during coal mining, the mining method is generally adopted, that is, before mining, the air inlet chute 40 and the return air chute 50 are first opened deep into the coal seam, and then the air inlet chute 40 and the return air chute 50 are opened through the cut to form an air inlet and return system. The coal body surrounded by the air inlet chute 40, the return air chute 50 and the cut forms the initial working face 20, and the working face support 60 and the coal mining equipment are set at the cut position, and the working face 20 can be continuously pushed forward from the cut position along the length extension direction of the air inlet chute 40 and the return air chute 50.

[0052] During the mining process of the working face 20, the area where the coal body where the mining is completed will be covered by the coal gangue of the roof collapse to form the goaf 10. As the working face 20 is continuously mined, the area of ​​the goaf 10 becomes larger and larger, and the area of ​​the working face 20 becomes smaller and smaller. The area between the goaf 10 and the working face 20 constitutes the cut eye 30. As the working face 20 is continuously mined, the position of the cut eye 30 is also constantly changing, and the position of the cut eye 30 is constantly moving forward along the length extension direction of the air inlet chute 40 and the return air chute 50. The working face support 60 and the coal mining equipment are located in the cut eye 30, and the working face support 60 and the coal mining equipment will also change with the change of the position of the cut eye 30.

[0053] It is understandable that in the actual mining process of the working face 20, not only the area where the coal body where the mining is completed is located will be covered by the coal gangue of the collapsed roof, but also the area of ​​the air intake chute 40 and the return air chute 50 corresponding to the part of the coal body and the position of the opening of the cutting eye will be covered by the collapsed coal gangue. Therefore, the "mined-out area 10" described in the embodiment of the present application includes not only the area where the coal body where the mining is completed is located, but also the area of ​​the air intake chute 40 and the return air chute 50 corresponding to the area where the part of the coal body is located, and the area where the opening of the cutting eye is located.

[0054] A roof roadway is provided in the roof of the coal mining face 100, or a floor roadway 200 is provided in the floor of the coal mining face 100. Optionally, the roof roadway may be a high extraction roadway; the floor roadway 200 may be a bottom extraction roadway, a drainage roadway, a transport roadway or a ventilation roadway.

[0055] The top plate tunnel or the bottom plate tunnel 200 is formed as a drilled tunnel for drilling construction, and the projection of the drilled tunnel in the first reference plane is located between the projection of the inlet chute 40 in the first reference plane and the projection of the return air chute 50 in the first reference plane, wherein the first reference plane is a plane parallel to the length extension direction of the inlet chute 40, the length extension direction of the return air chute 50 and the length extension direction of the cutting eye 30.

[0056] The method for monitoring the three spontaneous combustion zones of the goaf 10 of the coal mining face 100 according to the embodiment of the present application comprises the following steps:

[0057] S1: Please refer to Figure 1 and Figure 2 , multiple drilling channels 70 are drilled from the inner wall of the drilling tunnel toward the goaf 10, and the two ends of each drilling channel 70 in the length direction are respectively a drilling start end 71 and a drilling terminal 72, each drilling terminal 72 is located in the goaf 10, and each drilling start end 71 is located on the inner wall of the drilling tunnel, and multiple drilling terminals 72 are sequentially spaced along the first direction, wherein the first direction is a direction parallel to the length extension direction of the cut eye 30. The position where the center of the "drilling terminal 72" of each drilling channel 70 is located is the position where the gas sampling point of the goaf 10 is located.

[0058] It should be noted that in the present application, the drilling of the "drilling channel 70" is performed after a certain range of the goaf 10 is formed, and the specific range of the goaf 10 to be drilled after the formation needs to be selected according to the actual situation. For example, the drilling of the drilling channel 70 can be performed when the length of the goaf 10 along the length extension direction of the air inlet chute 40 and the air return chute 50 reaches 20m, 30m or 50m.

[0059] S2: Please refer to Figure 3 A plugging assembly 80 and an air extraction pipe 90 are arranged in the drilling channel 70. The plugging assembly 80 is used to plug the open port 711 of the drilling start end 71 so as to form a sealed detection cavity 73 in the drilling channel 70. One end of the air extraction pipe 90 passes through the plugging assembly 80 to extend into the detection cavity 73. The other end of the air extraction pipe 90 is located in the drilling tunnel and connected to the gas sampling device 201. The gas sampling device 201 can be arranged in the drilling tunnel. Optionally, the gas sampling device 201 can be a gas sampling pump.

[0060] S3: During the mining process of the working face 20, the gas in each detection cavity 73 is sampled regularly by using the gas sampling device 201, and the components of the sampled gas in each detection cavity 73 are detected to obtain the oxygen concentration value in each detection cavity 73, and the oxygen concentration value of each detection cavity 73 and the distance between the corresponding drilling terminal 72 and the working face 20 are recorded. As the working face 20 is continuously mined, the area range of the goaf 10 will gradually increase, and the area range of the working face 20 will gradually decrease. Therefore, the distance between the drilling terminal 72 and the working face 20 will continue to increase, and the drilling terminal 72 will gradually enter the depth of the goaf 10. The oxygen concentration value of the sampled gas will gradually decrease until the sampling is stopped when it is detected that the oxygen concentration value in the sampled gas is lower than the preset oxygen concentration threshold.

[0061] The oxygen concentration threshold can be selected according to actual needs. For example, the oxygen concentration threshold can be 5%. Of course, the present application is not limited thereto. In some other examples, the oxygen concentration threshold can also be 8%.

[0062] In addition, before using the gas sampling device 201 to take gas from each detection chamber 73, the gas in the detection chamber 73 can be discharged first, and then sampling and analysis can be performed 5 minutes after the discharge. This can avoid the influence of residual gas in the drilling channel 70 on the mixing of gas in the goaf 10, thereby ensuring that the sampled gas can truly reflect the oxygen concentration in the gas at the measuring point position in the goaf 10.

[0063] S4: According to the corresponding variation law between the oxygen concentration value in each detection cavity 73 and the distance between the corresponding drilling terminal 72 and the working face 20, the distribution range of the three spontaneous combustion zones of the goaf 10 of the coal mining working face 100 is determined. How to determine the division of the three zones by the corresponding variation law between the oxygen concentration value and the distance between the corresponding drilling terminal 72 and the working face 20 is common knowledge to those skilled in the art and will not be described here.

[0064] See also Figure 5The "three zones" of the goaf 10 include the heat dissipation zone 10a, the oxidation zone 10b and the asphyxiation zone 10c. The heat dissipation zone 10a has sufficient oxygen supply conditions, but due to the large air leakage, the small heat generated in the early stage of coal oxidation and spontaneous combustion is lost with the wind. The coal oxidation process always stays in the slow development stage, and it is not easy for coal spontaneous combustion to occur. It should be pointed out that the oxygen concentration is used as an indicator to define the heat dissipation zone 10a and the oxidation zone 10b. It is not because the oxygen concentration is greater than a certain value and cannot spontaneously ignite, but because the leakage wind speed in this area is too high to take away the heat generated by oxidation. Therefore, the heat dissipation zone 10a is often called the "cooling zone" or "heat dissipation zone 10a"; the oxidation zone 10b has sufficient oxygen supply conditions, and because of the small air leakage, the oxidation heat storage environment is better, the coal oxidation self-heating process can continue, and finally leads to the occurrence of coal spontaneous combustion. Due to the lack of oxygen in the asphyxiation zone 10c, the coal oxidation and spontaneous combustion process will not be able to proceed.

[0065] The "three zones" of the goaf 10 are divided by the oxygen concentration critical value index parameter, and the oxygen concentration critical value can be selected as needed. Optionally, the oxygen concentration critical value can be 5% and 15%. Specifically, the oxygen concentration value greater than 15% is the heat dissipation zone 10a; the oxygen concentration value greater than or equal to 5% and less than or equal to 15% is the oxidation zone 10b; the oxygen concentration value less than 5% is the asphyxiation zone 10c. In some other examples, the oxygen concentration critical value can be 8% and 18%.

[0066] According to the monitoring method of the three spontaneous combustion zones of the goaf 10 of the coal mining face 100 of the embodiment of the present application, by implementing directional drilling construction from the roof roadway or the floor roadway 200 into the goaf 10 to form a drilling channel 70 for gas sampling, it is possible to avoid the mixing of gases from other locations into the drilling channel 70 under conditions such as multiple coal seams, complex geological structures, and ventilation disorders, thereby affecting the sampled gas composition, and greatly shorten the length of the drilling channel 70, thereby greatly shortening the drilling distance, and the drilling direction will not have a large deviation, thereby ensuring the accuracy of the gas measurement point position in the goaf 10. In addition, construction drilling in the roof roadway or the floor roadway 200 can also reduce drilling costs and save drilling time, thereby improving monitoring efficiency.

[0067] Furthermore, by performing drilling construction from the roof tunnel or the floor tunnel 200 toward the goaf 10, the mining work of the working face 20 will not be affected, thereby ensuring the mining efficiency.

[0068] Furthermore, the exhaust pipe 90 is installed in the drilling channel 70, which can avoid the risk of being damaged by the collapsed coal gangue during the mining process of the working face 20, and can ensure the authenticity of the sampled gas. In addition, the exhaust pipe 90 required in the embodiment of the present application only needs to introduce the gas in the drilling channel 70 into the roof roadway or the floor roadway 200 and connect it to the gas sampling device 201. The length of the exhaust pipe 90 only needs to ensure that it can extend from the drilling channel 70 to the roof roadway or the floor roadway 200. Compared with the length of the bundle pipe pre-buried in the air inlet chute 40 and the return air chute 50 in the related art, it is greatly shortened.

[0069] Furthermore, by arranging multiple drilling terminals 72 in the goaf 10 at intervals along the length extension direction of the cutting eye 30, as the mining operation of the working face 20 proceeds, the position of the drilling terminal 72 in the goaf 10 will change, and the drilling terminal 72 gradually enters the depth of the goaf 10. By regularly sampling and analyzing the gas in each drilling channel 70, it is possible to obtain the corresponding change relationship between the oxygen concentration value in the gas in the goaf 10 at the location of each drilling terminal 72 and the mining distance of the working face 20, thereby determining the distribution range of the three spontaneous combustion zones in the goaf 10 of the coal mining working face 100. That is to say, in the present application, it is only necessary to drill multiple borehole channels 70 from the roof tunnel or the floor tunnel 200 toward the goaf 10, and make the borehole terminals 72 of the multiple borehole channels 70 spaced apart in the goaf 10 along the length extension direction of the cut eye 30, and by regularly sampling and analyzing the gas in each borehole channel 70, the distribution range of the three spontaneous combustion zones in the goaf 10 of the coal mining working face 100 can be obtained. In the embodiment of the present application, the number of boreholes required to be opened is small, and the division accuracy of the three spontaneous combustion zones is related to the gas sampling frequency in each borehole channel 70. In the mining work of the working face 20, by increasing the gas sampling frequency in the borehole channel 70, the division accuracy of the three spontaneous combustion zones can be improved without increasing the number of borehole channels 70 in the mining direction.

[0070] Furthermore, when the drilling tunnel for drilling construction is a roof tunnel, the influence of water on the drilling can be eliminated; when the drilling tunnel for drilling construction is a floor tunnel 200, in addition to being used to extract gas samples, the drilling channel itself can also be used for drainage, avoiding the risk of coal sludge formed by water accumulation in the goaf 10 flooding or blocking the sampling point.

[0071] In some embodiments of the present application, when the drilled tunnel is a roof tunnel, the vertical distance between the drilled tunnel and the coal mining face 100 is greater than 15 times the mining height. In most cases, the working face 20 adopts retreat mining, and the roof of the rear goaf 10 will continue to collapse with the impact of mining. Generally, 3 to 5 times the mining height above the roof is the collapse zone, and 10 to 15 times the mining height above the roof is the fracture zone. The rock fragments and voids in the collapse zone and the fracture zone may become channels or storage spaces for harmful substances such as gas and water. In order to reduce the impact on the extracted gas composition and concentration, the vertical distance between the roof tunnel and the working face 20 is preferably greater than 15 times the mining height. In some other examples, the vertical distance between the drilled tunnel and the coal mining face 100 can also be less than 15 times the mining height.

[0072] When the drilled tunnel is the floor tunnel 200, the collapse of the roof of the goaf 10 will cause damage to the support system of the floor tunnel 200. The vertical distance between the floor tunnel 200 and the working face 20 varies depending on the specific conditions of the coal mine, and some may be closer (such as tens of meters) and some may be farther (such as hundreds of meters). Therefore, when the distance between the floor tunnel 200 and the working face 20 is closer, the support strength of the floor tunnel 200 needs to be strengthened.

[0073] In some embodiments of this application, please refer to Figure 1 , the plurality of drilling terminals 72 are evenly spaced in the first direction. That is, the distance between the centers of each two adjacent drilling terminals 72 in the first direction is equal.

[0074] For further information, please refer to Figure 1 , the distance L1 between the centers of two adjacent drilling terminals 72 in the first direction ranges from 40m to 70m. That is, the distance L1 between the centers of two adjacent drilling terminals 72 in the first direction may be greater than or equal to 40m and less than or equal to 70m. Exemplarily, the distance L1 may be 40m, 50m, 60m or 70m, etc. By making the distance L1 range from 40m to 70m, the accuracy of the division of the spontaneous combustion "three zones" is ensured while reducing the number of boreholes. In some other examples, the distance L1 may also be less than 40m or greater than 70m.

[0075] For further information, please refer to Figure 1, the centers of multiple drilling terminals 72 are located on the same straight line, and the straight line extends along the first direction. That is to say, the centers of multiple drilling terminals 72 are arranged at the same horizontal position after the goaf 10 racks. It can be understood that the position where the center of the drilling terminal 72 is located is the position where the measuring point of the goaf 10 is located, by making the centers of multiple drilling terminals 72 located at the same horizontal position after the goaf 10 racks, that is, making multiple measuring points located at the same horizontal position after the goaf 10 racks. In this way, during the mining process of the working face 20, the distances between multiple measuring points and the working face 20 are the same, and it is only necessary to detect the distance between one of the measuring points and the working face 20, and there is no need to detect the distance between each measuring point and the working face 20.

[0076] For further information, see Figure 1 , the distance L2 between the center of each drilling terminal 72 and the wall of the goaf 10 facing the cut eye 30 in the second direction is in the range of 5m~10m, that is, the distance L2 can be greater than or equal to 5m and less than or equal to 10m. Exemplarily, the distance L2 can be 5m, 6m, 7m, 8m, 9m or 10m, etc. The second direction is a direction parallel to the length extension direction of the inlet chute 40 and the length extension direction of the return air chute 50. That is to say, the horizontal position of the center of each drilling terminal 72 is located 5m~10m from the goaf behind the working face 20, so that the critical value of the oxygen concentration described above can be detected more quickly. In some other examples, the distance L2 can also be less than 5m or greater than 10m.

[0077] Furthermore, the length of the portion of each drilling channel 70 located in the goaf 10 in the third direction is greater than or equal to 0.5 m, wherein the third direction is a direction perpendicular to both the first direction and the second direction. In other words, the drilling terminal 72 vertically penetrates the goaf 10 by no less than 0.5 m. This can ensure the authenticity of the sampled gas, thereby ensuring the accuracy of the spontaneous combustion "three zones" division. In some other examples, the length of the portion of each drilling channel 70 located in the goaf 10 in the third direction can also be less than 0.5 m.

[0078] Furthermore, the axis of each drilling channel 70 is parallel to the second reference plane, wherein the second reference plane is a plane perpendicular to the second direction, thereby shortening the length of the drilling channel 70 and reducing the difficulty of construction.

[0079] In one embodiment of the present application, see Figure 1 One of the multiple drilling terminals 72 is located in the air inlet chute 40 of the goaf 10, and one of the multiple drilling terminals 72 is located in the return air chute 50 of the goaf 10. This can improve the accuracy of the division of the spontaneous combustion "three zones".

[0080] In the present application, the number of drilling channels 70 can be determined according to the inclined length of the working surface 20, so as to take into account the difficulty of drilling construction and the accuracy of the division of the spontaneous combustion "three zones". Figure 1 The inclination length of the working face 20 is 200m, the number of drilling channels 70 can be five, one of which is located in the air inlet chute 40 of the goaf 10, one is located in the return air chute 50 of the goaf 10, and the other three are evenly distributed in the goaf 10 between the air inlet chute 40 and the return air chute 50. The distance L1 between the centers of two adjacent drilling terminals 72 in the first direction is 50m.

[0081] The following describes a method for monitoring the spontaneous combustion "three zones" of the goaf 10 of a coal mining face 100 by taking a specific embodiment as an example.

[0082] In this embodiment, the drilling tunnel is a floor tunnel 200 located in the floor of the coal mining working face 100, and the distance between the floor tunnel 200 and the working face 20 is 40m, the inclination length of the working face 20 is 264m, and five drilling tunnels are drilled from the drilling tunnel toward the goaf 10. The distance L1 between the centers of two adjacent drilling terminals 72 in the first direction is 66m, and the distance L2 between the center of each drilling terminal 72 and the wall of the goaf 10 facing the cut eye 30 in the second direction is 6m, that is, the horizontal position of the drilling terminal 72 is 6m away from the goaf 10 behind the working face 20, and the drilling terminal 72 vertically penetrates the goaf 10 by no less than 0.5m. The five drilling channels 70 are marked as 1#, 2#, 3#, 4# and 5# respectively. The layout parameters of each drilling channel 70 are shown in Table 1 below:

[0083]

[0084] The corresponding relationship between the oxygen concentration of the sampled gas in each drilling channel 70 and the distance between the corresponding drilling terminal 72 and the working surface 20 is shown in Table 2 below:

[0085]

[0086] According to the data in Table 2 above, we can conclude that Figure 6 The variation trend diagram between the oxygen concentration in each drilling channel 70 and the distance between the drilling terminal 72 and the working surface 20 is shown in FIG. Figure 6 (a) is a graph showing the change trend between the oxygen concentration in the drilling channel 1# and the distance between the drilling terminal 72 and the working surface 20. Figure 6 (b) is a graph showing the variation trend between the oxygen concentration in the drilling channel 2# and the distance between the drilling terminal 72 and the working surface 20. Figure 6 (c) is a graph showing the variation trend between the oxygen concentration in the drilling channel 3# and the distance between the drilling terminal 72 and the working surface 20. Figure 6(d) is a graph showing the variation trend between the oxygen concentration in the drilling channel 4# and the distance between the drilling terminal 72 and the working surface 20. Figure 6 (e) is a graph showing the variation trend of the oxygen concentration in the borehole channel 5# and the distance between the borehole terminal 72 and the working face 20. Through the variation trend of the oxygen concentration in each borehole channel 70, the distribution of the spontaneous combustion "three zones" in the goaf 10 of the coal mining working face 100 can be obtained as shown in Table 3:

[0087]

[0088] In one embodiment of the present application, see Figure 3 The plugging assembly 80 includes: a first plugging member 81, a second plugging member 82, a grouting pipe 83, a return grouting pipe 84 and a grouting filling layer 85. The first plugging member 81 and the second plugging member 82 are arranged at intervals in the drilling channel 70. The first plugging member 81 is located on the side of the second plugging member 82 away from the drilling starting end 71, one end of the grouting pipe 83 passes through the second plugging member 82 to extend into the gap between the first plugging member 81 and the second plugging member 82, and the other end of the grouting pipe 83 is located in the drilling tunnel and is suitable for connecting a grouting device. One end of the return grouting pipe 84 passes through the second plugging member 82 to extend into the gap between the first plugging member 81 and the second plugging member 82, and the other end of the return grouting pipe 84 is located in the drilling tunnel. The length of the return grouting pipe 84 between the first plugging member 81 and the second plugging member 82 is greater than the length of the grouting pipe 83 between the first plugging member 81 and the second plugging member 82. The grouting filling layer 85 is arranged in the drilling channel 70 and between the first plugging member 81 and the second plugging member 82, and is used to fill the gap between the first plugging member 81 and the second plugging member 82. The plugging assembly 80 in this embodiment of the present application has good sealing performance and high reliability. Optionally, the first plugging member 81 and the second plugging member 82 can both be expansion capsules.

[0089] The grouting pipe 83 is used to inject grout between the first plugging piece 81 and the second plugging piece 82. That is, the grouting device transports the grouting slurry to the space between the first plugging piece 81 and the second plugging piece 82 through the grouting pipe 83. The return grouting pipe 84 is used to remind that the slurry is full. Specifically, when the grouting slurry fills the gap between the first plugging piece 81 and the second plugging piece 82, part of the slurry will overflow from the return grouting pipe 84 into the drilled tunnel. When the grouting staff finds that the grouting slurry overflows from the return grouting pipe 84, it means that the slurry is full and the grouting can be stopped. The grouting filling layer 85 is formed by the grouting device injecting grout between the first plugging piece 81 and the second plugging piece 82 through the grouting pipe 83. After solidification, the grouting filling layer 85 plays a role in sealing the hole and fixing the pipe. The grouting slurry can be an expansive cement slurry.

[0090] For further information, please refer to Figure 3The plugging assembly 80 further includes a slurry layer 86, which is disposed in the drilling channel 70 and located on the side of the second plugging member 82 away from the first plugging member 81, and the surface of the slurry layer 86 away from the second plugging member 82 is flush with the periphery of the open opening 711 of the drilling start end 71. The slurry layer 86 can be formed by applying slurry on the side of the second plugging member 82 away from the first plugging member 81. The applied slurry can be an expansive cement slurry. During the specific construction process, before grouting is performed between the first sealing piece 81 and the second sealing piece 82 to form the grouting filling layer 85, a grouting layer 86 can be first set on the side of the second sealing piece 82 away from the first sealing piece 81. After the grouting layer 86 solidifies, grouting is performed to form the grouting filling layer 85. After the grouting layer 86 solidifies, it can fix the second sealing piece 82 to prevent the second sealing piece 82 from moving out of the drilling channel 70. Therefore, the risk of the second sealing piece 82 being unstable in positioning and squeezed out of the drilling channel 70 by the slurry during grouting can be avoided.

[0091] It can be understood that the axial port of one end of the exhaust pipe 90 located in the detection chamber 73 forms an exhaust hole 91, and the gas in the detection chamber 73 enters the exhaust pipe 90 through the exhaust hole 91 and is transported to the gas sampling device 201 through the exhaust pipe 90. In order to improve the exhaust efficiency of the exhaust pipe 90, in one embodiment of the present application, refer to Figure 3 An auxiliary air extraction hole 92 is formed on the circumferential side wall of one end of the air extraction pipe 90 located in the detection chamber 73. In this way, the gas in the detection chamber 73 can not only enter the air extraction pipe 90 through the air extraction port, but also enter the air extraction pipe 90 through the auxiliary air extraction hole 92, thereby improving the air extraction efficiency of the air extraction pipe 90. Figure 3 The auxiliary air extraction holes 92 include a plurality of them, and the plurality of auxiliary air extraction holes 92 are evenly distributed on the circumferential side wall of the air extraction pipe 90 so that the end of the air extraction pipe 90 located in the detection chamber 73 forms a flower tube structure. Furthermore, the end of the air extraction pipe 90 located in the detection chamber 73 is covered with a filter screen, and the filter screen can filter the gas entering the air extraction pipe 90, that is, the gas in the detection chamber 73 is filtered by the filter screen, and then enters the air extraction pipe 90 through the air extraction holes 91 and the auxiliary air extraction holes 92, so that the debris in the drilling channel 70 can be prevented from entering the air extraction pipe 90.

[0092] Refer to the following Figure 4The monitoring method of the three spontaneous combustion zones in the goaf 10 of the coal mining face 100 according to the second aspect embodiment of the present application is described. The monitoring method of the three spontaneous combustion zones in the goaf 10 of the coal mining face 100 according to the second aspect embodiment of the present application is similar to the monitoring method of the three spontaneous combustion zones in the goaf 10 of the coal mining face 100 according to the first aspect embodiment described above, with the only difference being that in the monitoring method of the three spontaneous combustion zones in the goaf 10 of the coal mining face 100 according to the second aspect embodiment of the present application, the tunnels used for drilling construction are the first tunnel 300 and the second tunnel 400.

[0093] Specifically, a first lane 300 is formed on the side of the air inlet chute 40 away from the return air chute 50, and the length extension direction of the first lane 300 is parallel to the length extension direction of the air inlet chute 40. A second lane 400 is formed on the side of the return air chute 50 away from the air inlet chute 40, and the length extension direction of the second lane 400 is parallel to the length extension direction of the return air chute 50. It should be noted that in the present application, the "first lane 300" and the "second lane 400" can be coal lanes or rock lanes, which can be used for transportation, ventilation, drainage, gas extraction or preparation of working face lanes, etc. The "first lane 300" and the "second lane 400" can be lanes of adjacent coal mining working faces 100, or they can be dedicated lanes of the coal mining working face 100.

[0094] The monitoring method includes the following steps:

[0095] S1: A first drilling channel 70a is drilled from the first tunnel 300 toward the goaf 10. The two ends of the first drilling channel 70a in the length direction are respectively the first drilling start end 70a1 and the first drilling terminal 70a2. The first drilling start end 70a1 is located on the inner wall surface of the first tunnel 300. The first drilling terminal 70a2 is located in the goaf 10. The center of the first drilling terminal 70a2 in the goaf 10 is one of the measuring point positions. A second drilling channel 70b is drilled from the second tunnel 400 toward the goaf 10. The two ends of the second drilling channel 70b in the length direction are respectively the second drilling start end 70b1 and the second drilling terminal 70b2. The second drilling start end 70b1 is located on the inner wall surface of the second tunnel 400. The second drilling terminal 70b2 is located in the goaf 10. The center of the second drilling terminal 70b2 in the goaf 10 is another measuring point position. The first drilling terminal 70 a 2 and the second drilling terminal 70 b 2 are spaced apart from each other in the goaf 10 along the lengthwise extension direction of the cut eye 30 .

[0096] S2: A first plugging component and a first exhaust pipe are arranged in the first drilling channel 70a, the first plugging component is used to plug the open mouth of the starting end 70a1 of the first drilling hole so that a sealed first detection cavity is formed in the first drilling channel 70a, one end of the first exhaust pipe passes through the first plugging component to extend into the first detection cavity, the other end of the first exhaust pipe is located in the first lane 300 and is connected to the first gas sampling device 301, and a second plugging component and a second exhaust pipe are arranged in the second drilling channel 70b, the second plugging component is used to plug the open mouth of the starting end 70b1 of the second drilling hole so that a sealed second detection cavity is formed in the second drilling channel 70b, one end of the second exhaust pipe passes through the second plugging component to extend into the second detection cavity, the other end of the second exhaust pipe is located in the second lane 400 and is connected to the second gas sampling device 401.

[0097] It should be noted that the structure and function of the "first plugging assembly" and the "second plugging assembly" described here are the same as the structure and function of the "plugging assembly 80" described above, the structure and function of the "first exhaust pipe" and the "second exhaust pipe" described here are the same as the structure and function of the "exhaust pipe 90" described above, and the "first gas sampling device 301" and the "second gas sampling device 401" described here have the same function as the "gas sampling device 201" described above, and they will not be repeated here.

[0098] S3: During the mining process of the working face 20, the first gas sampling device 301 and the second gas sampling device 401 are used to periodically sample the gas in the first detection chamber and the second detection chamber, respectively, and the components of the sampled gas in the first detection chamber and the second detection chamber are detected to obtain the oxygen concentration values ​​in the first detection chamber and the second detection chamber, and the oxygen concentration value of the first detection chamber and the distance from the first drilling terminal 70a2 to the working face 20, as well as the oxygen concentration value of the second detection chamber and the distance from the second drilling terminal 70b2 to the working face 20 are recorded respectively. As the working face 20 is continuously mined, the oxygen concentration value of the sampled gas will decrease until the oxygen concentration value in the sampled gas is lower than the preset oxygen concentration threshold, and sampling is stopped. The "preset oxygen concentration threshold" mentioned here has been explained in detail above and will not be repeated here.

[0099] S4: Based on the corresponding change law between the oxygen concentration value in the first detection chamber and the distance between the first drilling terminal 70a2 and the working face 20, as well as the corresponding change law between the oxygen concentration value in the second detection chamber and the distance between the second drilling terminal 70b2 and the working face 20, the distribution range of the three spontaneous combustion zones in the goaf 10 of the coal mining working face 100 is determined.

[0100] In summary, in the monitoring method for the three spontaneous combustion zones in the goaf 10 of the coal mining face 100 in the first aspect of the present application, the drilled roadway is a bottom plate roadway 200 or a roof plate roadway, and in the monitoring method for the three spontaneous combustion zones in the goaf 10 of the coal mining face 100 in the second aspect of the present application, the drilled roadway is a first roadway 300 and a second roadway 400, and the bottom plate roadway 200, the roof plate roadway, the first roadway 300 and the second roadway 400 are all adjacent roadways of the goaf 10 of the coal mining face 100. In other words, the monitoring method for the three spontaneous combustion zones in the goaf 10 of the coal mining face 100 in the first aspect of the present application and the monitoring method for the three spontaneous combustion zones in the goaf 10 of the coal mining face 100 in the second aspect of the present application are both based on drilling a drilling channel 70 for gas sampling from the adjacent roadways of the goaf 10 of the coal mining face 100 toward the goaf 10. The advantages of drilling a borehole channel 70 for gas sampling toward the goaf 10 based on the adjacent tunnel of the goaf 10 of the coal mining face 100 have been described in detail above and will not be repeated here.

[0101] In one embodiment of the present application, see Figure 4 , the first drilling terminal 70a2 is located in the air inlet chute 40 of the goaf 10, and the second drilling terminal 70b2 is located in the return air chute 50 of the goaf 10. In this way, not only can the drilling distance between the first drilling channel 70a and the second drilling channel 70b be shortened, the drilling efficiency can be improved, but also the division accuracy of the spontaneous combustion "three zones" can be improved. Of course, the present application is not limited to this. In some other embodiments, the first drilling terminal 70a2 and the second drilling terminal 70b2 can also be located in the area between the air inlet chute 40 and the return air chute 50 of the goaf 10.

[0102] For further information, please refer to Figure 4 , the straight line formed by the center of the first drilling terminal 70a2 and the center of the second drilling terminal 70b2 is parallel to the first direction, wherein the first direction is a direction parallel to the length extension direction of the cut eye 30. In this way, the center of the first drilling terminal 70a2 and the center of the second drilling terminal 70b2 are at the same distance from the working surface 20, that is, the center of the first drilling terminal 70a2 and the center of the second drilling terminal 70b2 are located at the same horizontal position after 10 frames of the goaf. Since the position where the center of the first drilling terminal 70a2 and the center of the second drilling terminal 70b2 are located is the position where the measuring point of the goaf 10 is located, by making the center of the first drilling terminal 70a2 and the center of the second drilling terminal 70b2 located at the same horizontal position after 10 frames of the goaf, that is, making multiple measuring points located at the same horizontal position after 10 frames of the goaf. In this way, during the mining process of the working face 20 , the distances between multiple measuring points and the working face 20 are the same, and it is only necessary to detect the distance between one of the measuring points and the working face 20 , without detecting the distance between each measuring point and the working face 20 .

[0103] For further information, see Figure 4 , the range of the distance D1 between the center of the first drilling terminal 70a2 and the wall of the goaf 10 facing the cut eye 30 in the second direction, and the range of the distance D2 between the center of the second drilling terminal 70b2 and the wall of the goaf 10 facing the cut eye 30 in the second direction are both 5m~10m. That is to say, the distance D1 and the distance D2 can be greater than or equal to 5m and less than or equal to 10m. Exemplarily, the distance D1 and the distance D2 can be 5m, 6m, 7m, 8m, 9m or 10m, etc. Among them, the second direction is a direction parallel to the length extension direction of the inlet chute 40 and the length extension direction of the return air chute 50. That is to say, the horizontal positions of the center of the first drilling terminal 70a2 and the center of the second drilling terminal 70b2 are both located 5m~10m behind the working face 20 frame in the goaf, so that the critical value of the oxygen concentration described above can be detected more quickly. In some other examples, the distance D1 and the distance D2 can also be less than 5m or greater than 10m.

[0104] Furthermore, the length of the portion of the first drilling channel 70a located in the goaf 10 along the third direction is greater than or equal to 0.5m, and the length of the portion of the second drilling channel 70b located in the goaf 10 along the third direction is greater than or equal to 0.5m, wherein the third direction is a direction perpendicular to both the first direction and the second direction. In other words, the first drilling terminal 70a2 and the second drilling terminal 70b2 vertically penetrate into the goaf 10 by no less than 0.5m. In this way, the authenticity of the sampled gas can be ensured, thereby ensuring the accuracy of the spontaneous combustion "three zones" division. In some other examples, the length of the portion of the first drilling channel 70a and the second drilling channel 70b located in the goaf 10 in the third direction can also be less than 0.5m.

[0105] Furthermore, the axis of the first drilling channel 70a and the axis of the second drilling channel 70b are both parallel to the second reference plane, wherein the second reference plane is a plane perpendicular to the second direction, thereby shortening the length of the first drilling channel 70a and the second drilling channel 70b and reducing the construction difficulty.

[0106] In the description of the present application, “plurality” means two or more than two, unless otherwise clearly and specifically defined.

[0107] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0108] In the description of this application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0109] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0110] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A method for monitoring the three spontaneous combustion zones in the goaf of a coal mining face, characterized in that: The coal mining working face comprises a goaf, a working face, a cut-out, an air inlet chute and a return air chute. The cut-out is located between the goaf and the working face. A working face support is suitable for being arranged in the cut-out. The air inlet chute and the return air chute are respectively arranged at both ends of the cut-out in the length direction and are connected to each other through the cut-out. A roof roadway is provided in the roof of the coal mining working face, or a bottom roadway is provided in the bottom of the coal mining working face, the roof roadway or the bottom roadway is formed as a drilling roadway for drilling construction, the projection of the drilling roadway in the first reference plane is located between the projection of the air inlet chute in the first reference plane and the projection of the return air chute in the first reference plane, wherein the first reference plane is a plane parallel to the length extension direction of the air inlet chute, the length extension direction of the return air chute and the length extension direction of the cut eye; The monitoring method comprises: S1: Drilling a plurality of drilling channels from the inner wall surface of the drilling tunnel toward the goaf, the two ends of each drilling channel in the length direction are respectively a drilling start end and a drilling end end, each drilling end end is located in the goaf, each drilling start end is located on the inner wall surface of the drilling tunnel, and the plurality of drilling ends are sequentially spaced along a first direction, wherein the first direction is a direction parallel to the length extension direction of the cut eye; S2: a plugging assembly and an exhaust pipe are arranged in the drilling channel, the plugging assembly is used to plug the open opening at the starting end of the drilling hole so as to form a sealed detection cavity in the drilling channel, one end of the exhaust pipe passes through the plugging assembly to extend into the detection cavity, and the other end of the exhaust pipe is located in the drilling tunnel and connected to a gas sampling device; S3: During the mining process of the working face, the gas in each detection cavity is sampled periodically by using the gas sampling device, and the components of the sampled gas in each detection cavity are detected to obtain the oxygen concentration value in each detection cavity, and the oxygen concentration value of each detection cavity and the distance of the corresponding drilling terminal from the working face are recorded. As the working face is continuously mined, the oxygen concentration value of the sampled gas will decrease until the sampling is stopped when it is detected that the oxygen concentration value in the sampled gas is lower than the preset oxygen concentration threshold value; S4: Determine the distribution range of the three spontaneous combustion zones in the goaf of the coal mining working face based on the corresponding change pattern between the oxygen concentration value in each detection chamber and the distance between the corresponding drilling terminal and the working face.

2. The method for monitoring the three spontaneous combustion zones in the goaf of a coal mining face according to claim 1 is characterized in that: When the drilled tunnel is the roof tunnel, the vertical distance between the drilled tunnel and the coal mining working face is greater than 15 times the mining height.

3. The method for monitoring the three spontaneous combustion zones in the goaf of a coal mining face according to claim 1 or 2, characterized in that: The plurality of drilling terminals are evenly spaced apart in the first direction; and / or The distance L1 between the centers of two adjacent drilling terminals in the first direction ranges from 40m to 70m; and / or The centers of the plurality of drilling terminals are located on the same straight line; and / or The distance L2 between the center of each drilling terminal and the wall of the goaf facing the cut-out in the second direction is in the range of 5m to 10m, wherein the second direction is a direction parallel to the length extension direction of the air inlet chute and the length extension direction of the air return chute; and / or The length of the portion of each of the drilled channels located in the goaf in the third direction is greater than or equal to 0.5 m, wherein the third direction is a direction perpendicular to both the first direction and the second direction; and / or The axis of each drilling channel is parallel to a second reference plane, wherein the second reference plane is a plane perpendicular to the second direction.

4. The method for monitoring the three spontaneous combustion zones in the goaf of a coal mining face according to claim 1 is characterized in that: One of the multiple drilling terminals is located in the air inlet chute of the goaf, and one of the multiple drilling terminals is located in the air return chute of the goaf.

5. The method for monitoring the three spontaneous combustion zones in the goaf of a coal mining face according to claim 1 is characterized in that: The blocking component comprises: a first blocking member and a second blocking member, wherein the first blocking member and the second blocking member are arranged in the drilling channel at an interval, and the first blocking member is located on a side of the second blocking member away from the starting end of the drilling; A grouting pipe, one end of which passes through the second plugging member to extend into the gap between the first plugging member and the second plugging member, and the other end of which is located in the drilled tunnel and is suitable for connecting a grouting device; a return slurry pipe, one end of which passes through the second plugging piece to extend into the gap between the first plugging piece and the second plugging piece, the other end of which is located in the drilled tunnel, and the length of the return slurry pipe between the first plugging piece and the second plugging piece is greater than the length of the grouting pipe between the first plugging piece and the second plugging piece; A grouting filling layer is arranged in the drilled channel and between the first plugging member and the second plugging member, and is used to fill the gap between the first plugging member and the second plugging member.

6. The method for monitoring the three spontaneous combustion zones in the goaf of a coal mining face according to claim 5 is characterized in that: The sealing assembly also includes a slurry layer, which is arranged in the drilling channel and located on the side of the second sealing member away from the first sealing member, and the surface of the slurry layer away from the second sealing member is flush with the periphery of the open mouth at the starting end of the drilling.

7. The method for monitoring the three spontaneous combustion zones in the goaf of a coal mining face according to claim 1 is characterized in that: An auxiliary air extraction hole is formed on the circumferential side wall of one end of the air extraction tube located in the detection cavity.

8. A method for monitoring the three spontaneous combustion zones in the goaf of a coal mining face, characterized in that: The coal mining working face comprises a goaf, a working face, a cut-out, an air inlet chute and a return air chute. The cut-out is located between the goaf and the working face. A working face support is suitable for being arranged in the cut-out. The air inlet chute and the return air chute are respectively arranged at two ends of the cut-out in the length direction and are connected to each other through the cut-out. A first lane is formed on a side of the air inlet chute away from the return air chute, and a length extension direction of the first lane is parallel to the length extension direction of the air inlet chute; a second lane is formed on a side of the return air chute away from the air inlet chute, and a length extension direction of the second lane is parallel to the length extension direction of the return air chute. The monitoring method comprises: S1: drilling a first drilling channel from the first tunnel toward the goaf, wherein two ends of the first drilling channel in the length direction are respectively a first drilling start end and a first drilling end end, the first drilling start end is located on the inner wall surface of the first tunnel, and the first drilling end end is located in the goaf, A second drilling channel is drilled from the second tunnel toward the goaf, the two ends of the second drilling channel in the length direction are respectively a second drilling start end and a second drilling end end, the second drilling start end is located on the inner wall surface of the second tunnel, the second drilling end end is located in the goaf, and the first drilling end end and the second drilling end end are spaced apart in the goaf along the length extension direction of the cut eye; S2: a first plugging component and a first exhaust pipe are arranged in the first drilling channel, the first plugging component is used to plug the open opening at the starting end of the first drilling hole so as to form a sealed first detection cavity in the first drilling channel, one end of the first exhaust pipe passes through the first plugging component to extend into the first detection cavity, and the other end of the first exhaust pipe is located in the first lane and connected to a first gas sampling device, A second plugging component and a second gas extraction pipe are arranged in the second drilling channel, the second plugging component is used to plug the open opening at the starting end of the second drilling hole so as to form a sealed second detection cavity in the second drilling channel, one end of the second gas extraction pipe passes through the second plugging component to extend into the second detection cavity, and the other end of the second gas extraction pipe is located in the second laneway and connected to a second gas sampling device; S3: During the mining process of the working face, the first gas sampling device and the second gas sampling device are used to periodically sample the gases in the first detection chamber and the second detection chamber respectively, and the components of the sampled gases in the first detection chamber and the second detection chamber are detected to obtain the oxygen concentration values ​​in the first detection chamber and the second detection chamber, and the detected oxygen concentration value of the first detection chamber and the distance from the first drilling terminal to the working face, as well as the detected oxygen concentration value of the second detection chamber and the distance from the second drilling terminal to the working face are recorded respectively. As the working face is continuously mined, the oxygen concentration value of the sampled gas will decrease until the oxygen concentration value in the sampled gas is detected to be lower than a preset oxygen concentration threshold, and sampling is stopped; S4: Based on the corresponding change law between the oxygen concentration value in the first detection chamber and the distance between the first drilling terminal and the working face, as well as the corresponding change law between the oxygen concentration value in the second detection chamber and the distance between the second drilling terminal and the working face, the distribution range of the three spontaneous combustion zones in the goaf of the coal mining working face is determined.

9. The method for monitoring the three spontaneous combustion zones in the goaf of a coal mining face according to claim 8 is characterized in that: The first drilling terminal is located in the air inlet chute of the goaf, and the second drilling terminal is located in the air return chute of the goaf.

10. The method for monitoring the three spontaneous combustion zones in the goaf of a coal mining face according to claim 8 or 9, characterized in that: The straight line formed by the center of the first drilling terminal and the center of the second drilling terminal is parallel to a first direction, wherein the first direction is a direction parallel to the length extension direction of the cut eye; and / or The range of the distance D1 in the second direction between the center of the first drilling terminal and the wall of the goaf facing the cut-eye and the range of the distance D2 in the second direction between the center of the second drilling terminal and the wall of the goaf facing the cut-eye are both 5m~10m, wherein the second direction is a direction parallel to the length extension direction of the inlet chute and the length extension direction of the return air chute; and / or The length of the portion of the first drilling channel located in the goaf along the third direction is greater than or equal to 0.5 m, and the length of the portion of the second drilling channel located in the goaf along the third direction is greater than or equal to 0.5 m, wherein the third direction is a direction perpendicular to both the first direction and the second direction; and / or The axis of the first drilling channel and the axis of the second drilling channel are both parallel to a second reference plane, wherein the second reference plane is a plane perpendicular to the second direction.

Images