Goaf foam fixed-point injection air leakage stoppage device and air leakage stoppage method

Abstract

The invention relates to a goaf foam fixed-point injection air leakage stoppage device and method, the air leakage stoppage device comprises two foam generating devices and a foam injection pipe, the two foam generating devices are arranged in an air inlet roadway and an air return roadway respectively and connected with forepoling hydraulic supports in the air inlet roadway and the air return roadway, and the foam injection pipe is connected with the forepoling hydraulic supports in the air inlet roadway and the air return roadway. The forepoling hydraulic support can drive the foam generating device to move forwards; coal wall pipe grooves extending in the front-back direction are formed in the protective coal pillars on the left side and the right side of the goaf, foam injection pipes are laid in the coal wall pipe grooves, the output end of the foam generation device communicates with the ends, away from the goaf, of the foam injection pipes, and a plurality of foam release openings are formed in the foam injection pipes at equal intervals in the length direction; and an old channel can be automatically closed and a new injection point can be opened along with collapse of overlying strata. According to the air leakage stoppage device, the foam injection pipe is laid on the coal wall of the protection coal pillar, the construction cost is low, the air leakage stoppage device cannot be crushed by fallen rocks, and meanwhile, the released foam can effectively block an air leakage channel in a triangular area.

Description

Technical Field

[0001] The invention relates to the technical field of coal mine goaf area air leakage plugging devices, and in particular to a goaf area foam fixed-point injection air leakage plugging device and an air leakage plugging method. Background Art

[0002] See also Figure 1 During the mining process of the coal seam working face, affected by the mining action, cracks connected to the adjacent working face, the upper working face and even the surface are often generated, which leads to air leakage in goaf 2, increases the ventilation demand of the working face, and may lead to a low oxygen environment, increasing the risk of spontaneous combustion of the coal in goaf 2. The coal in goaf 2 usually exists in the form of broken piles. Under the condition of continuous air leakage and oxygen supply, heat continues to accumulate, which can easily cause spontaneous combustion, seriously threatening the safe production of the mine and the life and health of workers. In addition, with the gradual collapse and compaction of the overlying rock strata, the air leakage channels in goaf 2 are mainly concentrated in the triangular area close to the protective coal pillar 5.

[0003] The existing coal mine goaf air leakage plugging device includes an isolation wall 6, a grouting pipe 7 and a nitrogen injection pipe 8. The air leakage plugging method based on the existing coal mine goaf air leakage plugging device includes: step S1, before the end of mining, according to the three-zone division standard of the goaf spontaneous combustion, the coal seam during the end-of-mining-stop-withdrawal period is divided into an isolation wall construction area, a grouting area and a nitrogen injection area for fire prevention and extinguishing in the end-of-mining stage; step S2, pre-burying grouting pipes 7 and nitrogen injection pipes 8 in the bottom plates of the air inlet tunnel 3 and the return air tunnel 4; step S3, constructing an isolation wall 6 in the isolation wall construction area; step S4, in the process of advancing the coal mining working face, grouting is injected into the goaf through the grouting pipe 7, and nitrogen is injected into the goaf 2 through the nitrogen injection pipe 8, so as to seal and inertate the gas in the goaf 2 to prevent the spontaneous combustion of the residual coal in the goaf 2. The defects and shortcomings of the existing coal mine goaf air leakage plugging devices and methods are as follows: (1) The grouting pipe 7 and the nitrogen injection pipe 8 are pre-buried in the tunnel floor, but the grouting effect is poor and the air leakage channel in the triangular area cannot be effectively plugged; (2) As the overlying rock layer in the goaf gradually collapses, the grouting pipe 7 and the nitrogen injection pipe 8 pre-buried in the tunnel floor are at risk of being crushed; (3) The buried pipe injection method is to place the pipeline on the tunnel floor. As the coal mining face advances forward, the pipeline is gradually pressed into the goaf, but it requires manual placement of the pipeline continuously, and there are overlapping areas between the pipelines, which leads to a lot of waste of consumables and high labor costs; (4) In the process of rapid advancement of the coal mining face, how to achieve the synchronous follow-up of plugging air leakage in the goaf 2 still faces many technical difficulties.

[0004] Therefore, there is an urgent need to provide a goaf area foam fixed-point injection plugging air leakage device and a plugging air leakage method with low cost and good plugging effect. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a device and method for plugging air leakage by fixed-point foam injection in goaf, which solves the technical problems that the existing device for plugging air leakage by fixed-point foam injection in goaf is complex in technology, has high construction cost, and is easily crushed by overlying rock strata.

[0007] (II) Technical solution

[0008] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0009] In a first aspect, an embodiment of the present invention provides a device for plugging air leakage by fixed-point foam injection in goaf, comprising two foam generating devices and a foam injection pipe;

[0010] The two foam generating devices are respectively arranged in the air inlet tunnel and the return air tunnel of the coal mining face, and are connected to the advance support hydraulic supports in the air inlet tunnel and the return air tunnel. The advance support hydraulic supports can drive the foam generating devices to move forward.

[0011] Coal wall pipe grooves extending in the front-to-back direction are opened on the protective coal pillars on the left and right sides of the goaf, and foam injection pipes are laid in the coal wall pipe grooves. The output end of the foam generating device is connected to the end of the foam injection pipe away from the goaf, and the foam injection pipe is provided with multiple foam release ports at equal intervals along the length direction.

[0012] Optionally, the foam generating device comprises a carrier vehicle, a gas-liquid mixing mechanism, a foam mixing mechanism, a foam storage tank and a foaming agent pump;

[0013] The front end of the advance support hydraulic support is hinged to the rear end of the carrying vehicle. The carrying vehicle is installed with a gas-liquid mixing mechanism, a foam mixing mechanism, a foam storage box and a foam pump. The gas-liquid mixing mechanism has an air inlet end, a liquid inlet end and a mixing output end connected to the air inlet end and the liquid inlet end. The mixing output end of the gas-liquid mixing mechanism is connected to the first input end of the foam mixing mechanism. The foam storage box is connected to the second input end of the foam mixing mechanism through the foam pump. The foam output end of the foam mixing mechanism is connected to the foam injection pipe.

[0014] Optionally, a metal mesh is provided at the connection between the foam output end of the foam mixing mechanism and the foam injection pipe.

[0015] Optionally, the advance support hydraulic support and the carrier vehicle are hinged via a flexible connection device.

[0016] Optionally, the advance support hydraulic support is provided with a tunnel compressed air pipeline and a tunnel water supply pipeline. The tunnel compressed air pipeline is connected to the air inlet end of the gas-liquid mixing mechanism to supply inert gas to the gas-liquid mixing mechanism, and the tunnel water supply pipeline is connected to the liquid inlet end of the gas-liquid mixing mechanism.

[0017] Optionally, the foam injection pipe has a plurality of sub-pipelines connected in sequence, and adjacent sub-pipelines are detachably connected via quick connectors.

[0018] Optionally, each foam release port is provided with an automatic opening assembly, the automatic opening assembly comprising a casing, a bevel gear 1, a bevel gear 2, a throttle plate and a pressure plate;

[0019] The outer wall of the foam injection pipe is provided with a casing at the foam release port, and the interior of the casing is used for positioning and supporting the first bevel gear and the second bevel gear, and the first bevel gear is meshed with the second bevel gear;

[0020] One end of the pressure plate is fixedly connected to the rotating shaft of bevel gear one, and the other end of the pressure plate extends into the goaf. The throttle plate is located in the foam injection pipe and is fixedly connected to the rotating shaft of bevel gear two, wherein the throttle plate can rotate between a closed position and a throttling position. In the closed position, the throttle plate closes the corresponding foam release port; and in the throttling position, the throttle plate opens the corresponding foam release port and prevents the foam from moving toward the rear along the foam injection pipe.

[0021] In a second aspect, an embodiment of the present invention provides a method for plugging air leakage by using the above-mentioned goaf area fixed-point foam injection plugging air leakage device, the method comprising the following steps: S1, trenching construction, comprising: digging a coal wall pipe trench extending in the front-to-back direction on the protective coal pillars on the left and right sides of the goaf; laying a foam injection pipe in the coal wall pipe trench;

[0022] S2. Air leakage detection to determine the location of the air leakage channel and the amount of air leakage;

[0023] S3. Determine the foam injection position according to the air leakage detection result in step S2: if there is an air leakage channel in the triangular area on one side of the air inlet tunnel, the foam generating device in the air inlet tunnel enters step S4; if there is an air leakage channel in the triangular area on one side of the return air tunnel, the foam generating device in the return air tunnel enters step S4; if there are air leakage channels in the triangular areas on both sides of the goaf, the foam generating devices in both the air inlet tunnel and the return air tunnel enter step S4;

[0024] S4, foam preparation, including: connecting the foam generating device with the advance support hydraulic support; connecting the output end of the foam generating device with the foam injection pipe in a one-to-one correspondence; the foam generating device prepares and generates foam;

[0025] S5. Foam injection: The foam generating device delivers the prepared foam to the foam injection pipe. The foam moves toward the rear side along the foam injection pipe and is released into the triangular area through the foam release port to block the air leakage channel in the triangular area.

[0026] Optionally, the air leakage plugging method further comprises:

[0027] S6, synchronous follow-up, including: disconnecting the foam generating device and the foam injection pipe, advancing the coal mining face forward, and the advanced support hydraulic support synchronously drives the foam generating device forward, and repeating steps S1-S5 until the coal mining operation is stopped.

[0028] Optionally, the trenching construction position of the coal wall pipe trench is 1-2m away from the tunnel floor.

[0029] (III) Beneficial effects

[0030] The beneficial effects of the present invention are as follows: the goaf area fixed-point foam injection plugging air leakage device of the present invention comprises two foam generating devices and a foam injection pipe; the two foam generating devices are respectively arranged in the air intake tunnel and the return air tunnel of the coal mining working face, and are connected to the advance support hydraulic supports in the air intake tunnel and the return air tunnel, and the advance support hydraulic supports can drive the foam generating device to move forward; coal wall pipe grooves extending in the front-to-back direction are provided on the protective coal pillars on the left and right sides of the goaf, and foam injection pipes are laid in the coal wall pipe grooves, the output end of the foam generating device is connected to the end of the foam injection pipe away from the goaf, and the foam injection pipe is provided with a plurality of foam release ports at equal intervals along the length direction, and when working, the foam generating device Generate foam, and the foam enters the goaf through the foam injection pipe on the protective coal pillar, thereby blocking the air leakage channel in the triangular area of ​​the protective coal pillar. Compared with the prior art, firstly, the goaf fixed-point foam injection and air leakage blocking device lays the foam injection pipe on the protective coal pillar, and its on-site construction is simple and low-cost, and the foam injection pipe in the protective coal pillar will not be crushed when the overlying rock stratum falls; secondly, the foam injection pipe is closer to the triangular area of ​​the coal pillar, so the foam released by the foam injection pipe can effectively block the air leakage channel; finally, when the coal mining working face advances forward, the advanced support hydraulic support can drive the foam generating device to move forward, and the goaf air leakage blocking device can be synchronously followed up without manual operation.

[0031] The method for plugging air leakage based on the goaf area foam fixed-point injection plugging air leakage device of the present invention adopts the coal wall groove-digging type foam fixed-point injection method. Compared with the adjacent tunnel and buried pipe injection methods, the method greatly reduces the cost and process difficulty and has high feasibility; the method can not only significantly reduce the oxygen concentration in the goaf, but also effectively alleviate the problem of hypoxia in the corners, thereby preventing coal spontaneous combustion and improving the safety of mining operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the layout structure of the isolation wall, grouting pipe and nitrogen injection pipe of the existing coal mine goaf area air leakage plugging device;

[0033] Figure 2 It is a top view schematic diagram of the goaf area fixed-point foam injection plugging air leakage device of the present invention when it is arranged on the coal mining working face;

[0034] Figure 3 for Figure 2 A cross-sectional schematic diagram of the goaf foam fixed-point injection plugging air leakage device at the goaf;

[0035] Figure 4 It is a schematic diagram of the connection structure between the foam generating device and the advanced support hydraulic support of the present invention;

[0036] Figure 5 It is a top view schematic diagram of the foam injection pipe of the present invention being laid in a protective coal pillar.

[0037] [Description of Reference Numerals]

[0038] 1: waiting area for mining; 2: goaf area; 3: air inlet tunnel; 4: return air tunnel; 5: protective coal pillar; 6: isolation wall; 7: grouting pipe; 8: nitrogen injection pipe;

[0039] 9: foam generating device; 10: foam injection pipe; 11: coal wall pipe groove; 12: foam release port; 13: advanced support hydraulic support; 14: tunnel compressed air pipeline; 15: tunnel water supply pipeline; 16: flexible connection device; 17: connecting tunnel; 18: carrier vehicle; 19: gas-liquid mixing mechanism; 20: foam mixing mechanism; 21: foam storage box; 22: metal mesh; 23: foam agent pump; 24: gear set one; 25: gear set two; 26: throttle plate; 27: pressure plate; 28: limit part; 29: overlying rock formation. DETAILED DESCRIPTION

[0040] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below in conjunction with the accompanying drawings through specific embodiments. Figure 2 It should be noted that, in this embodiment, the direction approaching the mining area 1 is "front", and the direction approaching the goaf 2 is "back", and the coal mining face is always moving forward to mine the coal in the mining area 1.

[0041] Please refer to Figure 2 and Figure 3 , Figure 2 The schematic diagram of the top view of the goaf area fixed-point foam injection plugging device of this embodiment when it is arranged on the coal mining working face is shown. Figure 3 for Figure 2 A partial cross-sectional schematic diagram of the goaf foam fixed-point injection plugging air leakage device in the goaf.

[0042] This embodiment provides a device for plugging air leakage in goaf by fixed-point foam injection, which includes two foam generating devices 9 and a foam injection pipe 10 .

[0043] The two foam generating devices 9 are respectively arranged in the air inlet tunnel 3 and the return air tunnel 4 of the coal mining face, and are connected to the advance support hydraulic support 13 in the air inlet tunnel 3 and the return air tunnel 4. The advance support hydraulic support 13 can drive the foam generating device 9 to move forward;

[0044] Coal wall pipe grooves 11 extending in the front-to-back direction are provided on the protective coal pillars 5 on the left and right sides of the goaf 2, and foam injection pipes 10 are laid in the coal wall pipe grooves 11. The output end of the foam generating device 9 is connected to the end of the foam injection pipe 10 away from the goaf 2. The foam injection pipe 10 is provided with a plurality of foam release ports 12 at equal intervals along the length direction. Preferably, the interval between adjacent foam release ports 12 is 3m.

[0045] The goaf area fixed-point foam injection and air leakage plugging device of this embodiment is implemented by laying the foam injection pipe 10 on the protective coal pillars 5 on the left and right sides of the goaf 2. When working, the foam generating device 9 generates foam, and the foam enters the goaf through the foam injection pipe 10 on the protective coal pillar 5, thereby plugging the air leakage channel at the triangular area of ​​the protective coal pillar 5. Compared with the existing coal mine goaf area air leakage plugging device, its on-site construction is simple and low in cost, and the overlying rock stratum 29 above the goaf 2 will not crush the foam injection pipe 10 when it falls. In addition, when the coal mining working face advances forward, the advance support hydraulic support 13 can drive the foam generating device 9 to move forward, and the synchronous follow-up of goaf air leakage plugging can be achieved without manual operation.

[0046] In this embodiment, the foam injection pipe 10 has a plurality of sub-pipelines connected in sequence, and adjacent sub-pipelines are detachably connected through quick connectors. The purpose of adopting the above structure is that when the coal mining face advances forward, a sub-pipeline can be added to the end of the foam injection pipe 10 away from the goaf 2 to increase the length of the foam injection pipe 10, which is convenient to use.

[0047] See also Figure 4 , Figure 4 The figure shows a schematic diagram of the connection structure between the foam generating device and the advance support hydraulic support of the present embodiment.

[0048] The foam generating device 9 of the present embodiment includes a carrier vehicle 18 , a gas-liquid mixing mechanism 19 , a foam mixing mechanism 20 , a foam storage tank 21 and a foaming agent pump 23 .

[0049] The front end of the advance support hydraulic support 13 is hinged to the rear end of the carrier vehicle 18. The carrier vehicle 18 is installed with a gas-liquid mixing mechanism 19, a foam mixing mechanism 20, a foam storage tank 21 and a foam agent pump 23. The gas-liquid mixing mechanism 19 has an air inlet end, a liquid inlet end and a mixing output end connected to the air inlet end and the liquid inlet end. The mixing output end of the gas-liquid mixing mechanism 19 is connected to the first input end of the foam mixing mechanism 20. The foam storage tank 21 is connected to the second input end of the foam mixing mechanism 20 through the foam agent pump 23. The foam output end of the foam mixing mechanism 20 is connected to the foam injection pipe 10.

[0050] When the foam generating device 9 is working, the gas and liquid enter the gas-liquid mixing mechanism 19 to mix, and then enter the foam mixing mechanism 20; at the same time, the foaming agent pump 23 pumps the foaming agent stored in the foam storage tank 21 into the foam mixing mechanism 20, and then the foaming agent and the gas-liquid mixture are mixed to generate a large amount of foam, and a large amount of foam finally enters the foam injection pipe 10 through the foam output end of the foam mixing mechanism 20, and enters the goaf 2 along the foam injection pipe 10. It should be noted that the foam mixing mechanism 20 can quantitatively calculate the foaming agent extraction rate after calibrating the wind pressure and water pressure entering the foam generating device 9, and the high-pressure water flow and air flow are mixed with the foaming agent in the pipeline of the foam mixing mechanism 20.

[0051] Furthermore, a metal mesh 22 is provided at the connection between the foam output end of the foam mixing mechanism 20 and the foam injection pipe 10. The metal mesh 22 is provided to generate stable foam.

[0052] In this embodiment, the advance support hydraulic support 13 and the carrier vehicle 18 are hinged by a flexible connection device 16. Preferably, the flexible connection device 16 is a connection device between train carriages, such as a James-type coupler. The purpose of such a setting is to ensure that the carrier vehicle 18 can turn relative to the advance support hydraulic support 13 on special sections to adapt to complex underground environments.

[0053] Furthermore, a connecting tunnel 17 is opened on the protective coal pillar 5 for connecting adjacent coal mining working faces, and the foam generating device 9 is arranged in the connecting tunnel 17 .

[0054] In this embodiment, a tunnel compressed air pipeline 14 and a tunnel water supply pipeline 15 are provided on the advance support hydraulic support 13. The tunnel compressed air pipeline 14 is connected to the air inlet end of the gas-liquid mixing mechanism 19, and the tunnel water supply pipeline 15 is connected to the liquid inlet end of the gas-liquid mixing mechanism 19.

[0055] It should be noted that the input ends of the tunnel compressed air pipeline 14 and the tunnel water supply pipeline 15 are laid along the coal mine tunnel to the ground, and are connected to the air supply equipment and water supply equipment on the ground respectively. In addition, the tunnel compressed air pipeline 14 is introduced with inert gas, which not only has pressure to provide power for the foam mixing mechanism 20 and promote the discharge of foam to the goaf 2, but also can inertize the gas in the goaf 2 to prevent the spontaneous combustion of the abandoned coal.

[0056] Combination Figure 3 and Figure 5 As shown, each foam release port 12 is provided with an automatic opening assembly, which includes a casing (not shown in the figure), a bevel gear 1 24 , a bevel gear 25 , a throttle plate 26 and a pressure plate 27 .

[0057] A casing is provided on the outer wall of the foam injection pipe 10 at the foam release port 12, and the casing is used for positioning and supporting bevel gear 1 24 and bevel gear 2 25, and bevel gear 1 24 is meshed with bevel gear 2 25; one end of a pressure plate 27 is fixedly connected to the rotating shaft of bevel gear 1 24, and the other end of the pressure plate 27 extends into the goaf 2, and a throttle plate 26 is located in the foam injection pipe 10 and is fixedly connected to the rotating shaft of bevel gear 25, and the throttle plate 26 can rotate between a closed position and a throttling position, and in the closed position, the throttle plate 26 closes the corresponding foam release port 12; and in the throttling position, the throttle plate 26 opens the corresponding foam release port 12 and prevents the foam from moving toward the rear along the foam injection pipe 10.

[0058] It should be noted that, initially, the throttle plate 26 is in the closed position, at which time the foam can move toward the rear along the foam injection pipe 10; when the overlying rock stratum 29 above the goaf 2 collapses, the rock presses the pressure plate 27 downward, and the pressure plate 27 drives the bevel gear 1 24 and the bevel gear 2 25 to rotate, and the rotation of the bevel gear 25 drives the throttle plate 26 to rotate from the closed position to the throttling position, opening the corresponding foam release port 12 while closing the rear foam injection pipe 10, thereby preventing the foam from moving toward the rear along the foam injection pipe 10.

[0059] Furthermore, the inner wall of the foam injection tube 10 is provided with a limiting portion 28 at the throttling position, and the limiting portion 28 is used to limit the rotation angle of the throttle plate 26. It should be noted that when the throttle plate 26 abuts against the limiting portion 28, the axial direction of the foam injection tube 10 is perpendicular to the plate surface of the throttle plate 26.

[0060] This embodiment also provides a method for plugging air leakage based on the above-mentioned goaf area foam fixed-point injection plugging air leakage device, and the plugging air leakage method comprises the following steps:

[0061] S1, trenching construction, including: digging a coal wall pipe trench 11 extending in the front-rear direction on the protective coal pillars 5 on the left and right sides of the goaf 2; laying a foam injection pipe 10 in the coal wall pipe trench 11;

[0062] S2. Air leakage detection, including: quantitatively releasing SF6 gas at a distance of 50m from the coal mining face in the air intake tunnel 3, and recording the release time; arranging sampling points at equal distances in the coal mining face and the return air tunnel 4, and monitoring the change of SF6 gas concentration in real time through the SF6 detector; according to the change of SF6 gas concentration at each sampling point, by comparing the SF6 gas concentration at different positions, combining the time parameter and the position parameter, the position of the air leakage channel and the amount of air leakage are obtained;

[0063] The air leakage calculation formula is:

[0064]

[0065] Where Q is the air leakage, m 3 / s; M is the total amount of SF6 gas injected, g; Δc is the SF6 gas concentration increment measured at the detection point, g / m 3 ; t is the time required for the gas to reach the detection point, s.

[0066] S3. Determine the foam injection position according to the air leakage detection result in step S2: if there is an air leakage channel in the triangular area on one side of the air inlet tunnel 3, the foam generating device 9 in the air inlet tunnel 3 enters step S4; if there is an air leakage channel in the triangular area on one side of the return air tunnel 4, the foam generating device 9 in the return air tunnel 4 enters step S4; if there are air leakage channels in the triangular areas on both sides of the goaf 2, the foam generating devices 9 in both the air inlet tunnel 3 and the return air tunnel 4 enter step S4;

[0067] S4, foam preparation, including: connecting the foam generating device 9 with the advance support hydraulic support 13; connecting the output end of the foam generating device 9 with the foam injection pipe 10 one by one; the foam generating device 9 prepares and generates foam;

[0068] S5, foam injection: the foam generating device 9 delivers the prepared foam to the foam injection pipe 10, the foam moves to the rear side along the foam injection pipe 10, and is released into the triangular area through the foam release port 12 on the foam injection pipe 10, thereby blocking the air leakage channel in the triangular area. As the overlying rock stratum 29 collapses, the rock presses the pressure plate 27 downward, driving the bevel gear 1 24 and the bevel gear 2 25 to rotate, and the throttle plate 26 rotates from the closed position to the throttling position, opening the foam release port 12 while closing the rear foam injection pipe 10, and the foam can be injected into the triangular area of ​​the coal wall close to the protective coal pillar 5 at a fixed point, blocking the air leakage channel between the goaf 2 and the outside.

[0069] In this embodiment, the trenching construction position of the coal wall pipe trench 11 is 1-2 m away from the tunnel floor. At this height, the construction is easiest and the diffusion range of the foam injection is maximized.

[0070] In this embodiment, the air leakage plugging method further includes:

[0071] S6, synchronous follow-up, including: disconnecting the foam generating device 9 and the foam injection pipe 10, the coal mining working face moves forward, and the advanced support hydraulic support 13 synchronously drives the foam generating device 9 to move forward to achieve synchronous follow-up, and finally repeating steps S1-S5 until the coal mining operation is stopped.

[0072] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0073] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 the present invention can be understood according to specific circumstances.

[0074] In the present invention, unless otherwise clearly specified and limited, when a first feature is “on” or “below” a second feature, it may be that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, when a first feature is “above”, “above” or “above” a second feature, it may be that the first feature is directly above or obliquely above the second feature, or it may simply mean that the first feature is higher in level than the second feature. When a first feature is “below”, “below” or “below” a second feature, it may be that the first feature is directly below or obliquely below the second feature, or it may simply mean that the first feature is lower in level than the second feature.

[0075] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" etc. 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 invention. In this specification, the schematic representations of the above terms do 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. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0076] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may alter, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A device for plugging air leakage by fixed-point foam injection in goaf, characterized in that: It comprises two foam generating devices (9) and a foam injection pipe (10); The two foam generating devices (9) are respectively arranged in the air inlet tunnel (3) and the return air tunnel (4) of the coal mining working face, and are connected to the advance support hydraulic support (13) in the air inlet tunnel (3) and the return air tunnel (4), and the advance support hydraulic support (13) can drive the foam generating device (9) to move forward; Coal wall pipe grooves (11) extending in the front-rear direction are provided on the protective coal pillars (5) on the left and right sides of the goaf (2), a foam injection pipe (10) is laid in the coal wall pipe groove (11), an output end of the foam generating device (9) is connected to an end of the foam injection pipe (10) away from the goaf (2), and a plurality of foam release ports (12) are provided on the foam injection pipe (10) at equal intervals along the length direction.

2. The device for plugging air leakage by fixed-point foam injection in goaf as claimed in claim 1, characterized in that: The foam generating device (9) comprises a carrier vehicle (18), a gas-liquid mixing mechanism (19), a foam mixing mechanism (20), a foam storage tank (21) and a foaming agent pump (23); The front end of the advanced support hydraulic support (13) is hinged to the rear end of a carrier vehicle (18); a gas-liquid mixing mechanism (19), a foam mixing mechanism (20), a foam storage box (21) and a foam agent pump (23) are installed on the carrier vehicle (18); the gas-liquid mixing mechanism (19) comprises an air inlet end, a liquid inlet end and a mixing output end connected to the air inlet end and the liquid inlet end; the mixing output end of the gas-liquid mixing mechanism (19) is connected to a first input end of the foam mixing mechanism (20); the foam storage box (21) is connected to a second input end of the foam mixing mechanism (20) via the foam agent pump (23); and the foam output end of the foam mixing mechanism (20) is connected to a foam injection pipe (10).

3. The device for plugging air leakage by fixed-point foam injection in goaf as claimed in claim 2, characterized in that: A metal mesh (22) is provided at the connection between the foam output end of the foam mixing mechanism (20) and the foam injection pipe (10).

4. The device for plugging air leakage by fixed-point foam injection in goaf as claimed in claim 2, characterized in that: The advanced support hydraulic support (13) and the carrier vehicle (18) are hinged via a flexible connection device (16).

5. The device for plugging air leakage by fixed-point foam injection in goaf as claimed in claim 2, characterized in that: The advanced support hydraulic support (13) is provided with a tunnel compressed air pipeline (14) and a tunnel water supply pipeline (15); the tunnel compressed air pipeline (14) is connected to the air inlet end of the gas-liquid mixing mechanism (19) to supply inert gas to the gas-liquid mixing mechanism (19); and the tunnel water supply pipeline (15) is connected to the liquid inlet end of the gas-liquid mixing mechanism (19).

6. The device for plugging air leakage by fixed-point foam injection in goaf as claimed in claim 1, characterized in that: The foam injection pipe (10) has a plurality of sub-pipelines connected in sequence, and adjacent sub-pipelines are detachably connected via quick interfaces.

7. The device for plugging air leakage by fixed-point foam injection in goaf as claimed in claim 1, characterized in that: Each foam release port (12) is provided with an automatic opening component, which comprises a casing, a bevel gear 1 (24), a bevel gear 2 (25), a throttle plate (26) and a pressure plate (27); The outer wall of the foam injection pipe (10) is provided with a casing at the foam release port (12), the interior of the casing is used for positioning and supporting bevel gear 1 (24) and bevel gear 2 (25), and bevel gear 1 (24) is meshed with bevel gear 2 (25); One end of the pressure plate (27) is fixedly connected to the rotating shaft of the bevel gear one (24), and the other end of the pressure plate (27) extends into the goaf (2). The throttle plate (26) is located in the foam injection pipe (10) and is fixedly connected to the rotating shaft of the bevel gear two (25), wherein the throttle plate (26) can rotate between a closed position and a throttling position. In the closed position, the throttle plate (26) closes the corresponding foam release port (12); and in the throttling position, the throttle plate (26) opens the corresponding foam release port (12) and prevents the foam from moving toward the rear along the foam injection pipe (10).

8. A method for plugging air leakage based on the goaf area foam fixed-point injection plugging air leakage device according to any one of claims 1 to 7, characterized in that: The air leakage blocking method comprises the following steps: S1, trenching construction, including: excavating a coal wall pipe trench (11) extending in the front-rear direction on the protective coal pillars (5) on the left and right sides of the goaf (2); laying a foam injection pipe (10) in the coal wall pipe trench (11); S2. Air leakage detection to determine the location of the air leakage channel and the amount of air leakage; S3. Determine the foam injection position according to the air leakage detection result in step S2: if there is an air leakage channel in the triangular area on one side of the air inlet tunnel (3), the foam generating device (9) in the air inlet tunnel (3) enters step S4; if there is an air leakage channel in the triangular area on one side of the return air tunnel (4), the foam generating device (9) in the return air tunnel (4) enters step S4; if there are air leakage channels in the triangular areas on both sides of the goaf (2), the foam generating devices (9) in both the air inlet tunnel (3) and the return air tunnel (4) enter step S4; S4, foam preparation, comprising: connecting the foam generating device (9) with the advance support hydraulic support (13); connecting the output end of the foam generating device (9) with the foam injection pipe (10) in a one-to-one correspondence; the foam generating device (9) generates foam; S5. Foam injection: The foam generating device (9) delivers the prepared foam to the foam injection pipe (10), and the foam moves toward the rear side along the foam injection pipe (10) and is released into the triangular area through the foam release port (12) to block the air leakage channel in the triangular area.

9. The air leakage plugging method according to claim 8, characterized in that: The air leakage blocking method also includes: S6, synchronous follow-up, including: disconnecting the foam generating device (9) and the foam injection pipe (10), the coal mining working face is advanced forward, and the advanced support hydraulic support (13) synchronously drives the foam generating device (9) to move forward, and steps S1-S5 are repeatedly executed until the coal mining operation is stopped.

10. The air leakage plugging method according to claim 8, characterized in that: In step S1, the trenching construction position of the coal wall pipe trench (11) is 1-2m away from the tunnel floor.

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