A monitoring system and early warning method for spontaneous combustion of water-soaked air-dried coal in underground coal mine goaf

Abstract

The present invention relates to a spontaneous combustion monitoring system for water-soaked air-dried coal in underground coal mine goafs, including a coal sample temperature monitor, a water body monitoring mechanism, a pressure monitoring mechanism, a gas monitoring device, a pressure monitor and a main control system. The coal sample temperature monitor is embedded in the residual coal in the goaf, the water body monitoring mechanism is embedded in the retained water body in the goaf, the gas monitoring device is embedded in the goaf and connected to the goaf roof through a connecting mechanism, the pressure monitoring mechanism is embedded in the supporting rock pile in the collapse area of ​​the goaf, and the pressure monitor is distributed along the axis direction of the goaf roof. Its operation method includes three steps: system assembly, data collection and spontaneous combustion judgment. The system of the present invention has good versatility, strong system adjustment and expansion capabilities, and can effectively meet the needs of coal seam spontaneous combustion detection and early warning operations in goafs of various geological structures and environments, and the detection data acquisition during the detection operation is comprehensive and the data collection accuracy is high.

Description

Technical Field

[0001] The invention relates to a spontaneous combustion monitoring system for water-soaked air-dried coal in an underground coal mine goaf and a use method thereof, belonging to the technical field of coal mine fire prevention. Background Art

[0002] Coal has always been one of the main energy sources in my country. Among the three major fossil energy sources, my country's coal reserves are far higher than oil and natural gas. In the future, coal will always occupy the most important position in the proportion and consumption of primary energy for a long period of time. In the shallow coal seams in Northwest my country, there is a large amount of groundwater influx in the goaf after mining. When the underlying coal seams are mined again, it is necessary to drain the overlying goaf. In this process, the overlying goaf is prone to water withdrawal and oxygen inflow. The coal samples in the goaf are prone to spontaneous combustion accidents of water-soaked coal after air drying, such as the spontaneous combustion accident of water-soaked coal that occurred in the Bulianta Coal Mine. Another possibility is that after the pre-oxidized coal sample is soaked in water in the goaf, the pre-oxidized coal sample may naturally dry due to the drop in the groundwater level, causing a coal spontaneous combustion accident.

[0003] At present, most of the prevention and control methods for mining the underlying coal seam are to use water exploration and water release to prevent water damage, but these measures often accelerate the occurrence of spontaneous combustion of waterlogged coal in the overlying goaf, ignoring the following problems that will promote the occurrence of coal spontaneous combustion: 1. Changes in the amount of water immersion and duration of the coal in the overlying goaf, 2. The amount of heat accumulation of the accumulated coal after the water recedes, 3. The gas content in the overlying goaf (mainly gas and oxygen), 4. The natural disaster characteristics of waterlogged air-dried loose coal under strong mine pressure, 5. The impact of residual harmful substances on coal heat accumulation after the water recedes in the goaf. Therefore, exploring the test system and implementation method of spontaneous combustion of waterlogged coal in the goaf is an issue that needs to be urgently solved.

[0004] Therefore, in order to improve the accuracy of early warning judgment of deep coal seam spontaneous combustion risk, it is urgent to develop an early warning system for deep coal spontaneous combustion and its use method to meet the needs of actual use. Summary of the invention

[0005] In order to solve the deficiencies in the prior art, the present invention provides a spontaneous combustion monitoring system for water-soaked air-dried coal in goaf areas of underground coal mines and a method for using the system.

[0006] A spontaneous combustion monitoring system for air-dried coal immersed in water in underground coal mine goafs, comprising a coal sample temperature monitor, a water monitoring mechanism, a pressure monitoring mechanism, a gas monitoring device, a pressure monitor and a main control system, wherein the main control system is electrically connected to the coal sample temperature monitor, the water monitoring mechanism, the pressure monitoring mechanism, the gas monitoring device and the pressure monitor respectively and establishes data connection through a communication network, a plurality of coal sample temperature monitors are embedded in the residual coal in the goaf, at least one water monitoring mechanism is embedded in the retained water body in the goaf and connected to the goaf bottom plate corresponding to the retained water body in the goaf, at least one gas monitoring device is embedded in the goaf and connected to the goaf top plate through a connecting mechanism, and the spacing between the gas monitoring device and the goaf axis is not greater than 1 / 3 of the goaf height, a plurality of pressure monitoring mechanisms are embedded in the supporting rock block pile in the collapse area of ​​the goaf, and a plurality of pressure monitors are embedded in the top of the goaf and distributed along the axis direction of the goaf top plate.

[0007] Furthermore, the coal sample temperature monitor includes an anchor head, a bearing column, a positioning frame, a bearing side plate, a temperature and humidity sensor, a pressure strain gauge, an electronic tag, a terminal block and an auxiliary circuit, wherein the bearing column is a hollow cylindrical structure, and its upper and lower end faces are both provided with sealing plugs, and the lower end face of the bearing column is connected to the anchor head and coaxially distributed, the terminal block is embedded in its upper end face, the outer surface of the bearing column is provided with at least two guide grooves which are parallel to its axis and evenly distributed around its axis, an auxiliary circuit is arranged in the top of the bearing column, the positioning frame is a frame structure with a rectangular cross section, which is covered on the outside of the bearing column and slidably connected to the bearing column through the guide groove, and the spacing between the lower end face of the positioning frame and the lower end face of the bearing column is not less than 2 / 3 of the height of the positioning frame, 1-2 electronic tags are arranged in the positioning frame, and the electronic tags are electrically connected to the terminal block; the bearing A plurality of side plates are slidably connected to the outer surface of the bearing column through guide grooves, and each bearing side plate is located below the positioning frame, and its plate surface forms an angle of 30°-90° with the axis of the bearing column. A plurality of temperature and humidity sensors are respectively embedded in the bearing column and evenly distributed from top to bottom along the axis of the bearing column. Two adjacent temperature and humidity sensors are isolated from each other by a sealing plate. The side walls of the bearing column corresponding to the temperature and humidity sensors are at least two through holes distributed on both sides of the axis of the bearing column, and the through holes on both sides of the axis of the bearing column are coaxially distributed, and the axis of the through holes intersects with the axis of the bearing column and forms an angle of 30°-90°. The front end surface of the bearing side plate is provided with a bearing groove coaxially distributed therewith, and a pressure strain gauge is provided in the bearing groove. The temperature and humidity sensor and the pressure strain gauge are connected in parallel with each other, and are electrically connected to the auxiliary circuit respectively, and the auxiliary circuit is also electrically connected to the main control system through the wiring terminal.

[0008] Furthermore, the water body monitoring mechanism includes a floating block, a bearing keel, a counterweight block, a bearing platform, a guide tube, a liquid level sensor, a water quality sensor, a water quality detection device and an auxiliary circuit. The bearing keel is a frame structure with a rectangular axial cross-section, and its lower end face is connected to the counterweight block, and is abutted and connected to the bottom of the water body through the counterweight block. The upper end face of the bearing keel is connected to the floating block through a traction rope, and the upper end face of the floating block is connected to the bearing platform. The bearing platform is a closed cavity structure with a rectangular cross-section, and its lower half is embedded in the upper end face of the floating block. The water quality detection device and the auxiliary circuit are both embedded in the bearing platform, and the auxiliary circuit is respectively connected to the liquid level sensor, the water quality detection device and the main control system circuit. Gas connection, the water quality detection device is also electrically connected with the water quality sensor, the guide tube is embedded in the load-bearing keel, coaxially distributed with the load-bearing keel and connected to the inner surface of the side wall of the load-bearing keel through a number of ribs, the side wall of the guide tube is evenly distributed with a number of through holes with an aperture of 1-5 mm, the liquid level sensor is embedded in the guide tube and coaxially distributed with the guide tube, and the upper end face of the liquid level sensor is connected to the upper end face of the guide tube, and the lower end face is against the upper end face of the counterweight block, there are at least three water quality sensors, two of which are embedded in the upper end face of the counterweight block and are evenly distributed around the axis of the guide tube and are located in the guide tube, and the remaining water quality sensors are embedded in the outer side of the guide tube and distributed around the axis of the guide tube.

[0009] Furthermore, the pressure monitoring mechanism includes a bearing base, a pressure sensor, a detection fin, an auxiliary circuit and a wiring terminal. There are at least two bearing bases, and two adjacent bearing bases are connected by 1-2 pressure sensors and coaxially distributed. The bearing base is a closed cavity structure with a rectangular cross-section, and at least two detection fins are provided on the outer surface of each bearing base. The detection fin is a plate-like structure with a rectangular cross-section, and the front ends of the detection fins of two adjacent bearing bases are connected by a pressure sensor. The bearing base is a closed cavity structure with a rectangular cross-section, and an auxiliary circuit is provided in each bearing base. At least one wiring terminal is provided on the outer side of the bearing base. The auxiliary circuit is electrically connected to the wiring terminal, and is electrically connected to the main control system and the auxiliary circuits of adjacent bearing bases through the wiring terminals.

[0010] Furthermore, the gas monitoring device includes a detection ring, a supporting column, an air environment monitoring mechanism, and an auxiliary circuit. The supporting column is a hollow cylindrical structure with an axis perpendicular to the horizontal plane, and its upper end face is hinged to the outer surface of a detection ring through a ratchet mechanism. The axis of the detection ring is perpendicular to and intersects with the axis of the supporting column. The detection ring includes a guide tube with a length of at least 1.5 times the diameter of the supporting column. The guide tubes are coaxially distributed and adjacent two guide tubes are connected to each other by at least three ribs. A number of air environment monitoring mechanisms are respectively embedded in the inner surface of each guide tube and evenly distributed around the axis of the guide tube. The air quality sensors are connected in parallel and electrically connected to the auxiliary circuit respectively. The auxiliary circuit is embedded in the supporting column and electrically connected to the main control system.

[0011] Furthermore, the pressure monitor includes an auxiliary circuit, a guide rail, an elastic hinge, a load-bearing spring, a tension sensor, a test bench, a pressure sensor, a pulley, a universal hinge, a slider and an elastic telescopic rod. The guide rails are several and distributed along the axis of the goaf and connected to the top plate of the goaf. The front end and rear end faces of the guide rails are connected to a load-bearing spring, and the guide rail and the load-bearing spring are hinged by an elastic hinge. The load-bearing springs connected to two adjacent guide rails are also connected by a tension sensor, and the load-bearing spring and the tension sensor are coaxially distributed. The test bench is cross-sectional. The surface is a rectangular plate-like structure, the upper end face of which is hinged to the slider through a universal hinge, and forms an angle of 0°-60° with the top plate of the goaf. The slider is also slidably connected to the guide rail, and the upper end face of the detection platform is also hinged to two elastic telescopic rods through an elastic hinge, and the axis of the elastic telescopic rod forms an angle of 30°-90° with the upper end face of the detection platform, the upper end face of the elastic telescopic rod is also connected to 1-2 pulleys through a pressure sensor, and the pulley is abutted against and slidably connected to the top plate of the goaf, and the auxiliary circuit is also embedded in the detection platform, and is electrically connected to the pressure sensor, tension sensor and main control system respectively.

[0012] Furthermore, the auxiliary circuit is a circuit system based on any one of DSP and FPGA chips, and the auxiliary circuit is further provided with a charge and discharge control circuit, an overload protection circuit and a driving battery pack.

[0013] Furthermore, the main control system is a data server based on big data, and the main control system is also provided with a number of control terminals based on PC computers and mobile intelligent communication terminals.

[0014] An operating method of a spontaneous combustion monitoring system for water-soaked air-dried coal in a coal mine goaf, comprising the following steps:

[0015] S1, system assembly, the axis is set up in the coal mine machine room to set up the main control system, and then set up a number of pressure monitors on the roof of the stepping area, set up at least one pressure monitoring mechanism in the supporting rock pile in each collapse area of ​​the goaf, set up at least one coal sample temperature monitor in each residual coal area of ​​the goaf, set up a water body monitoring mechanism in the residual water body of the goaf, and set up a number of gas monitoring devices in sequence along the exhaust direction of the goaf, and a coal sample temperature monitor, a water body monitoring mechanism, a pressure monitoring mechanism, a gas monitoring device, and a pressure monitor constitute a detection group, and set the detection groups in parallel and distributed along the axis of the goaf, and the distance between two adjacent detection groups is not less than 10 meters; finally, the coal sample temperature monitor, water body monitoring mechanism, pressure monitoring mechanism, gas monitoring device, and pressure monitor of each detection group are respectively connected with the main control system to establish data connection, and each detection group is assigned an independent communication address to complete the system configuration;

[0016] S2, data collection, after completing step S1, the main control system drives each detection group to run. When the detection group is running:

[0017] Coal sample temperature monitor: detects the internal temperature and accumulation temperature of the coal, and assists in detecting the internal structural pressure of the coal, and determines the natural risk of the coal based on the temperature and pressure of the coal;

[0018] Pressure monitoring mechanism: detect the internal pressure of the rock pile that has collapsed in the goaf and supports the operation at the top of the goaf, and assist in obtaining the pressure value of the coal left in the goaf. According to the pressure value of the coal left in the goaf, the natural risk of the coal left can be determined;

[0019] Pressure monitor: detects the deformation of the roof of the goaf during collapse and the pressure generated by the deformation, and cooperates with the pressure monitoring mechanism to further detect and determine the pressure value of the coal left in the goaf, so as to assist in judging the natural risk of the coal left;

[0020] Water monitoring agencies: Detect the depth and quality of the water remaining in the goaf. On the one hand, through the detection of suspended and dissolved matter in the water, the oxidation state of the coal residue is indirectly collected and analyzed; on the other hand, the water volume in the goaf is judged by the depth of the overflow water body, and the natural risk of the coal residue in the goaf is indirectly judged based on the water volume;

[0021] Gas monitoring device: measures the concentration of oxygen, carbon monoxide, methane and carbon dioxide in the air environment of the goaf, and determines the natural risk of coal residue based on the gas composition and content.

[0022] S3, spontaneous combustion judgment, based on the parameters collected in step S2, the main control system summarizes and analyzes the data collected by each detection group in step S2, so as to obtain the registration and judgment result of the spontaneous combustion risk of the coal sample.

[0023] The system of the present invention has good versatility and strong system adjustment and expansion capabilities. It can effectively meet the needs of coal seam spontaneous combustion detection and early warning operations in goafs of various geological structures and environments. The detection data during the detection operation is comprehensive and the data collection accuracy is high. It can simultaneously conduct comprehensive detection, collection and analysis of the coal seam temperature, coal seam stress state, goaf water content and goaf air composition in the goaf, thereby realizing the needs of accurate analysis of the storage state and spontaneous combustion state of the coal seam in the goaf and remote early warning operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments;

[0025] Figure 1 It is a schematic diagram of the system structure of the present invention;

[0026] Figure 2 This is a schematic diagram of the structure of a coal sample temperature monitor;

[0027] Figure 3 This is a schematic diagram of the water monitoring organization structure;

[0028] Figure 4 This is a schematic diagram of the water monitoring organization structure;

[0029] Figure 5 It is a schematic diagram of the structure of the pressure monitor;

[0030] Figure 6 It is a schematic diagram of the local structure of the pressure monitor;

[0031] Figure 7 It is a schematic diagram of the partial structure of the cross section of the pressure monitor;

[0032] Figure 8 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0033] In order to facilitate the construction of the technical means, creative features, objectives and effects achieved by the present invention, the present invention is further described below in conjunction with specific implementation methods.

[0034] like Figure 1As shown in FIG. 7 , a spontaneous combustion monitoring system for water-soaked air-dried coal in a goaf of an underground coal mine comprises a coal sample temperature monitor 1, a water body monitoring mechanism 2, a pressure monitoring mechanism 3, a gas monitoring device 4, a pressure monitor 5 and a main control system 6. The main control system 6 is electrically connected to the coal sample temperature monitor 1, the water body monitoring mechanism 2, the pressure monitoring mechanism 3, the gas monitoring device 4, and the pressure monitor 5, and establishes a data connection through a communication network. A plurality of coal sample temperature monitors 1 are embedded in the coal residue 7 in the goaf. The water body monitoring mechanism 2, the pressure monitoring mechanism 3, the gas monitoring device 4, and the pressure monitor 5 are electrically connected to the main control system 6. There is at least one mechanism 2, which is embedded in the retained water body 8 in the goaf and connected to the goaf bottom plate corresponding to the retained water body 8 in the goaf. There is at least one gas monitoring device 4, which is embedded in the goaf and connected to the goaf top plate through a connecting mechanism, and the distance between the gas monitoring device 4 and the axis of the goaf is not greater than 1 / 3 of the height of the goaf. There are several pressure monitoring mechanisms 3, which are embedded in the supporting rock block 9 pile in the collapsed area of ​​the goaf. There are several pressure monitors 5, which are embedded in the top of the goaf and distributed along the axis of the goaf top plate.

[0035] In this embodiment, the coal sample temperature monitor 1 includes an anchor head 101, a bearing column 102, a positioning frame 103, a bearing side plate 104, a temperature and humidity sensor 105, a pressure strain gauge 106, an electronic tag 107, a terminal block 108 and an auxiliary circuit 10, wherein the bearing column 102 is a hollow cylindrical structure, and its upper and lower end surfaces are both provided with sealing plugs 109, and the lower end surface of the bearing column 102 is connected to the anchor head 101 and coaxially distributed, the terminal block 108 is embedded in its upper end surface, and the outer surface of the bearing column 102 is provided with a sealing plug 109. At least two guide slots 11 are arranged parallel to the axis of the bearing column 102 and are evenly distributed around the axis of the bearing column 102. An auxiliary circuit 10 is arranged on the top of the bearing column 102. The positioning frame 103 is a frame structure with a rectangular cross section, which is covered outside the bearing column 102 and is slidably connected to the bearing column 102 through the guide slots 11. The spacing between the lower end surface of the positioning frame 103 and the lower end surface of the bearing column 102 is not less than 2 / 3 of the height of the positioning frame 103. One to two electronic tags 107 are arranged in the positioning frame 103, and the electronic tags 107 are electrically connected to the wiring terminal 108. The bearing side plates 104 are several, and are slidably connected to the outer surface of the bearing column 102 through the guide groove 11, and each bearing side plate 104 is located below the positioning frame 103, and its plate surface is at an angle of 30°-90° with the axis of the bearing column 102. The temperature and humidity sensors 105 are several, respectively embedded in the bearing column 102 and evenly distributed from top to bottom along the axis of the bearing column 102. The adjacent two temperature and humidity sensors 105 are isolated from each other by the sealing plate 12. The side walls of the bearing column 102 corresponding to the temperature and humidity sensors 105 are at least two distributed on the bearing column 102. There are through holes 13 on both sides of the axis of the column 102, and the through holes 13 on both sides of the axis of the bearing column 102 are coaxially distributed, and the axis of the through hole 13 intersects with the axis of the bearing column 102 and forms an angle of 30°-90°. The front end surface of the bearing side plate 104 is provided with a bearing groove 14 coaxially distributed therewith, and a pressure strain gauge 106 is provided in each of the bearing grooves 14. The temperature and humidity sensor 105 and the pressure strain gauge 106 are connected in parallel with each other and are electrically connected to the auxiliary circuit 10 respectively, and the auxiliary circuit 10 is also electrically connected to the main control system 6 through the wiring terminal 108.

[0036] Among them, the front end surface of the bearing side plate 104 exceeds the outer surface of the positioning frame 103 by at least 5 mm, and each bearing side plate 104 is distributed in a spiral structure around the axis of the bearing column 102. At the same time, the through hole 13 is located between two adjacent bearing side plates 104 distributed from top to bottom along the axis of the bearing column 102.

[0037] For further optimization, the anchor head 101 and the bearing column 102 are connected by a sleeve 14, and the sleeve 16 is respectively covered on the outside of the anchor head 101 and the bearing column 102, and is coaxially distributed with the anchor head 101 and the bearing column 102, and a pre-tensioning spring 15 is arranged in the sleeve 16, and the pre-tensioning spring 15 is respectively against the anchor head 101 and the bearing column 102 and is coaxially distributed.

[0038] In this embodiment, the water body monitoring mechanism 2 includes a floating block 21, a bearing keel 22, a counterweight block 23, a bearing platform 24, a guide tube 25, a liquid level sensor 26, a water quality sensor 27, a water quality detection device 28 and an auxiliary circuit 10. The bearing keel 22 is a frame structure with a rectangular axial section, and its lower end face is connected to the counterweight block 23, and is abutted and connected to the bottom of the water body through the counterweight block 23. The upper end face of the bearing keel 22 is connected to the floating block 21 through a traction rope 20, and the upper end face of the floating block 21 is connected to the bearing platform 24. The bearing platform 24 is a closed cavity structure with a rectangular cross-section, and its lower half is embedded in the upper end face of the floating block 21. The water quality detection device 28 and the auxiliary circuit 29 are both embedded in the bearing platform 24, and the auxiliary circuit 10 is respectively connected to the liquid level sensor 26, the water quality detection device 27 and the main control System 6 is electrically connected, and the water quality detection device 28 is also electrically connected to the water quality sensor 27. The guide tube 25 is embedded in the load-bearing keel 22, coaxially distributed with the load-bearing keel 22 and connected to the inner surface of the side wall of the load-bearing keel 22 through a number of ribs. The side wall of the guide tube 25 is evenly distributed with a number of through holes 13 with an aperture of 1-5 mm. The liquid level sensor 26 is embedded in the guide tube 25 and coaxially distributed with the guide tube 25, and the upper end face of the liquid level sensor 26 is connected to the upper end face of the guide tube 25, and the lower end face is against the upper end face of the counterweight block 23. There are at least three water quality sensors 27, two of which are embedded in the upper end face of the counterweight block 23 and are evenly distributed around the axis of the guide tube 25 and are located in the guide tube 25, and the remaining water quality sensors 27 are embedded in the outer side of the guide tube 25 and distributed around the axis of the guide tube 25.

[0039] The lower end surface of the floating block 21 is further provided with a guide sleeve 211 , which is covered on the outer surface of the bearing keel 22 and is slidably connected with the outer surface of the bearing keel 22 through the guide sleeve 211 .

[0040] At the same time, the water quality sensor 27 includes any one or a combination of a TOC sensor, a PH sensor, a conductivity sensor, an ORP sensor, a turbidity sensor, and a dissolved oxygen sensor;

[0041] Further optimized, the water quality sensor 27 includes a turbidity sensor, a dissolved oxygen sensor and any one or more of a TOC sensor, a PH sensor, a conductivity sensor, and an ORP sensor for use in combination.

[0042] In this embodiment, the pressure monitoring mechanism 3 includes a bearing base 31, a pressure sensor 32, a detection fin plate 33, an auxiliary circuit 10 and a wiring terminal 108. There are at least two bearing bases 31, and two adjacent bearing bases 31 are connected by 1-2 pressure sensors 32 and coaxially distributed. The bearing base 31 is a closed cavity structure with a rectangular cross-section, and at least two detection fin plates 33 are arranged on the outer surface of each bearing base 31. The detection fin plate 33 is a plate-like structure with a rectangular cross-section. The front ends of the detection fin plates 33 of two adjacent bearing bases 31 are connected by a pressure sensor 32. The bearing base 31 is a closed cavity structure with a rectangular cross-section, and an auxiliary circuit 10 is arranged in each bearing base 31. At least one wiring terminal 108 is arranged on the outer side of the bearing base 31. The auxiliary circuit 10 is electrically connected to the wiring terminal 108, and is electrically connected to the main control system 6 and the auxiliary circuit 10 of the adjacent bearing base 31 through the wiring terminal 108.

[0043] The plate surface of the detection fin plate 33 and the side surface of the supporting base 31 form an angle of 60°-90°, and the two detection fin plates 33 connected by the pressure sensor 32 between two adjacent supporting bases 31 form an isosceles triangle structure.

[0044] As a further optimization, in the bearing base 31 , two adjacent bearing bases 31 are connected via an auxiliary spring 34 , and the auxiliary spring 34 is wrapped around the pressure sensor 32 and coaxially distributed with the pressure sensor 32 .

[0045] In this embodiment, the gas monitoring device 4 includes a detection ring 41, a supporting column 42, an air environment monitoring mechanism 43, and an auxiliary circuit 10. The supporting column 42 is a hollow cylindrical structure with an axis perpendicular to the horizontal plane, and its upper end face is hinged to the outer surface of a detection ring 41 through a ratchet mechanism. The axis of the detection ring 41 is perpendicularly distributed and intersects with the axis of the supporting column 42. The detection ring 41 includes a guide tube 411 with a length of at least 1.5 times the diameter of the supporting column 42. The guide tubes 411 are coaxially distributed and adjacent two guide tubes 411 are connected to each other by at least three ribs 412. There are a number of air environment monitoring mechanisms 43, which are respectively embedded in the inner surface of each guide tube 411 and evenly distributed around the axis of the guide tube 411. The air quality sensors 43 are connected in parallel and are respectively electrically connected to the auxiliary circuit 10. The auxiliary circuit 10 is embedded in the supporting column 42 and is electrically connected to the main control system 6.

[0046] The air environment monitoring mechanism 43 includes any one or a combination of an air quality sensor, an air flow sensor, and an air pressure sensor.

[0047] In this embodiment, the pressure monitor 5 includes an auxiliary circuit 10, a guide rail 51, an elastic hinge 53, a load-bearing spring 54, a tension sensor 55, a detection platform 56, a pressure sensor 32, a pulley 59, a universal hinge 57, a slider 58 and an elastic telescopic rod 52. The guide rails 52 are multiple and distributed along the axis of the goaf and connected to the top plate of the goaf. The front end and rear end faces of the guide rail 51 are both connected to a load-bearing spring 54, and the guide rail 51 and the load-bearing spring 54 are hinged by an elastic hinge 53, and the load-bearing springs 54 connected to two adjacent guide rails 51 are connected by a tension sensor 55, and the load-bearing spring 54 and the tension sensor 55 are coaxially distributed. The platform 56 is a plate-like structure with a rectangular cross-section, and its upper end surface is hinged to the slider 58 through a universal hinge 57, and forms an angle of 0°-60° with the top plate of the goaf. The slider 58 is also slidably connected to the guide rail 51. The upper end surface of the detection platform 56 is also hinged to two elastic telescopic rods 52 through an elastic hinge 53, and the axis of the elastic telescopic rod 52 forms an angle of 30°-90° with the upper end surface of the detection platform 56. The upper end surface of the elastic telescopic rod 52 is also connected to 1-2 pulleys 59 through a pressure sensor 32, and the pulley 59 is abutted against and slidably connected to the top plate of the goaf. The auxiliary circuit 10 is also embedded in the detection platform 56, and is electrically connected to the pressure sensor 32, the tension sensor 55 and the main control system 6 respectively.

[0048] In this embodiment, the auxiliary circuit 10 is a circuit system based on any one of DSP and FPGA chips, and the auxiliary circuit 10 is further provided with a charge and discharge control circuit, an overload protection circuit and a driving battery pack.

[0049] In this embodiment, the main control system 6 is a data server based on big data, and the main control system is also provided with a number of control terminals based on PC computers and mobile intelligent communication terminals.

[0050] like Figure 8 As shown, a method for operating a spontaneous combustion monitoring system for water-soaked air-dried coal in a coal mine goaf includes the following steps:

[0051] S1, system assembly, the axis is set up in the coal mine machine room to set up the main control system, and then set up a number of pressure monitors on the roof of the stepping area, set up at least one pressure monitoring mechanism in the supporting rock pile in each collapse area of ​​the goaf, set up at least one coal sample temperature monitor in each residual coal area of ​​the goaf, set up a water body monitoring mechanism in the residual water body of the goaf, and set up a number of gas monitoring devices in sequence along the exhaust direction of the goaf, and a coal sample temperature monitor, a water body monitoring mechanism, a pressure monitoring mechanism, a gas monitoring device, and a pressure monitor constitute a detection group, and set the detection groups in parallel and distributed along the axis of the goaf, and the distance between two adjacent detection groups is not less than 10 meters; finally, the coal sample temperature monitor, water body monitoring mechanism, pressure monitoring mechanism, gas monitoring device, and pressure monitor of each detection group are respectively connected with the main control system to establish data connection, and each detection group is assigned an independent communication address to complete the system configuration;

[0052] S2, data collection, after completing step S1, the main control system drives each detection group to run. When the detection group is running:

[0053] Coal sample temperature monitor: detects the internal temperature and accumulation temperature of the coal, and assists in detecting the internal structural pressure of the coal, and determines the natural risk of the coal based on the temperature and pressure of the coal;

[0054] Pressure monitoring mechanism: detect the internal pressure of the rock pile that has collapsed in the goaf and supports the operation at the top of the goaf, and assist in obtaining the pressure value of the coal left in the goaf. According to the pressure value of the coal left in the goaf, the natural risk of the coal left can be determined;

[0055] Pressure monitor: detects the deformation of the roof of the goaf during collapse and the pressure generated by the deformation, and cooperates with the pressure monitoring mechanism to further detect and determine the pressure value of the coal left in the goaf, so as to assist in judging the natural risk of the coal left;

[0056] Water monitoring agencies: Detect the depth and quality of the water remaining in the goaf. On the one hand, through the detection of suspended and dissolved matter in the water, the oxidation state of the coal residue is indirectly collected and analyzed; on the other hand, the water volume in the goaf is judged by the depth of the overflow water body, and the natural risk of the coal residue in the goaf is indirectly judged based on the water volume;

[0057] Gas monitoring device: measures the concentration of oxygen, carbon monoxide, methane and carbon dioxide in the air environment of the goaf, and determines the natural risk of coal residue based on the gas composition and content.

[0058] S3, spontaneous combustion judgment, based on the parameters collected in step S2, the main control system summarizes and analyzes the data collected by each detection group in step S2, so as to obtain the registration and judgment result of the spontaneous combustion risk of the coal sample.

[0059] During the evaluation process:

[0060] The pre-oxidation degree of the underground coal is collected through the coal sample temperature monitor, and then the pre-oxidation temperature (low-temperature oxidation (below 200°C), high-temperature oxidation) is established; the gas monitoring device is used to measure the index gas (CH4, C2H4, CO) and the coal temperature changes to inhibit its further oxidation and spontaneous combustion.

[0061] The water body monitoring mechanism monitors the real-time water level changes, and collects data together with the pressure monitor to the signal collection system to make periodic judgments on the susceptibility to spontaneous combustion of coal samples that have been immersed in water for 180 days (Class I), one year (Class II), and more than one year (Class III).

[0062] The pressure monitor is transmitted to the signal collection system through the sensor track after the overlying roof collapses. According to the simulated axial pressure experiment, we avoid the roof to press the 4-6MP self-ignition pressure category.

[0063] The multiple sensor monitors in the upper goaf are distributed in a multi-mode, multi-node, multi-region, and multi-network manner at the location. Each monitor monitors the spontaneous combustion mechanism of coal under single or multi-field coupling such as temperature field, stress field, flow field, etc. in the upper goaf in real time.

[0064] The system of the present invention has good versatility and strong system adjustment and expansion capabilities. It can effectively meet the needs of coal seam spontaneous combustion detection and early warning operations in goafs of various geological structures and environments. The detection data during the detection operation is comprehensive and the data collection accuracy is high. It can simultaneously conduct comprehensive detection, collection and analysis of the coal seam temperature, coal seam stress state, goaf water content and goaf air composition in the goaf, thereby realizing the needs of accurate analysis of the storage state and spontaneous combustion state of the coal seam in the goaf and remote early warning operations.

[0065] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A system for monitoring spontaneous combustion of water-soaked air-dried coal in underground coal mine goaf, characterized in that: The spontaneous combustion monitoring system for water-soaked air-dried coal in the goaf of an underground coal mine comprises a coal sample temperature monitor, a water body monitoring mechanism, a pressure monitoring mechanism, a gas monitoring device, a pressure monitor and a main control system. The main control system is electrically connected to the coal sample temperature monitor, the water body monitoring mechanism, the pressure monitoring mechanism, the gas monitoring device and the pressure monitor, respectively, and establishes a data connection through a communication network. A plurality of coal sample temperature monitors are embedded in the residual coal in the goaf. There is at least one water body monitoring mechanism, which is embedded in the retained water body in the goaf and is connected to the goaf floor corresponding to the retained water body in the goaf. There is at least one gas monitoring device, which is embedded in the goaf and connected to the goaf floor through a connecting mechanism. The coal sample temperature monitor comprises an anchor head, a bearing column, a positioning frame, a bearing side plate, a temperature and humidity sensor, a pressure strain gauge, an electronic tag, a wiring terminal and an auxiliary circuit, wherein the bearing column is a hollow cylindrical structure, and its upper and lower end faces are both provided with sealing plugs, and the lower end face of the bearing column is connected to the anchor head and coaxially distributed, and the wiring terminal is embedded in its upper end. The outer surface of the bearing column is provided with at least two guide grooves which are parallel to the axis of the bearing column and evenly distributed around the axis of the bearing column. An auxiliary circuit is arranged in the top of the bearing column. The positioning frame is a frame structure with a rectangular cross section, which is covered on the outside of the bearing column and slidably connected to the bearing column through the guide groove. The spacing between the lower end surface of the positioning frame and the lower end surface of the bearing column is not less than 2 / 3 of the height of the positioning frame. 1-2 electronic tags are arranged in the positioning frame, and the electronic tags are electrically connected to the wiring terminals. Several bearing side plates are slidably connected to the outer surface of the bearing column through the guide groove, and each bearing side plate is located below the positioning frame, and its plate surface forms an angle of 30°-90° with the axis of the bearing column. The temperature A plurality of humidity sensors are respectively embedded in the bearing column and evenly distributed from top to bottom along the axis of the bearing column. Two adjacent temperature and humidity sensors are isolated from each other by a sealing plate. The side walls of the bearing column corresponding to the temperature and humidity sensors are at least two through holes distributed on both sides of the axis of the bearing column, and the through holes on both sides of the axis of the bearing column are coaxially distributed, and the axis of the through hole intersects with the axis of the bearing column and forms an angle of 30°-90°. The front end surface of the bearing side plate is provided with a bearing groove coaxially distributed therewith, and a pressure strain gauge is provided in each of the bearing grooves. The temperature and humidity sensors and the pressure strain gauges are connected in parallel with each other and are electrically connected to the auxiliary circuit respectively, and the auxiliary circuit is electrically connected to the main control system through a wiring terminal;The water body monitoring mechanism includes a floating block, a bearing keel, a counterweight block, a bearing platform, a guide tube, a liquid level sensor, a water quality sensor, a water quality detection device and an auxiliary circuit. The bearing keel is a frame structure with a rectangular axial cross-section, and its lower end face is connected to the counterweight block, and is abutted and connected to the bottom of the water body through the counterweight block. The upper end face of the bearing keel is connected to the floating block through a traction rope, and the upper end face of the floating block is connected to the bearing platform. The bearing platform is a closed cavity structure with a rectangular cross-section, and its lower half is embedded in the upper end face of the floating block. The water quality detection device and the auxiliary circuit are both embedded in the bearing platform, and the auxiliary circuit is electrically connected to the liquid level sensor, the water quality detection device and the main control system respectively. The water quality detection device is also respectively connected to the water quality sensor Electrical connection, the guide tube is embedded in the load-bearing keel, coaxially distributed with the load-bearing keel and connected to the inner surface of the side wall of the load-bearing keel through a number of ribs, the side wall of the guide tube is evenly distributed with a number of through holes with an aperture of 1-5 mm, the liquid level sensor is embedded in the guide tube and coaxially distributed with the guide tube, and the upper end face of the liquid level sensor is connected to the upper end face of the guide tube, and the lower end face is against the upper end face of the counterweight block, there are at least three water quality sensors, two of which are embedded in the upper end face of the counterweight block and are evenly distributed around the axis of the guide tube and are located in the guide tube, and the remaining water quality sensors are embedded in the outer side of the guide tube and distributed around the axis of the guide tube; the pressure monitoring mechanism includes a load-bearing base, a pressure sensor, a detection fin plate, an auxiliary circuit and a wiring terminal , there are at least two supporting bases, and two adjacent supporting bases are connected and coaxially distributed by 1-2 pressure sensors. The supporting base is a closed cavity structure with a rectangular cross section, and at least two detection fins are arranged on the outer surface of each supporting base. The detection fin is a plate-like structure with a rectangular cross section. The front ends of the detection fins of two adjacent supporting bases are connected by a pressure sensor. The supporting base is a closed cavity structure with a rectangular cross section, and an auxiliary circuit is arranged in each supporting base. At least one wiring terminal is arranged on the outer side of the supporting base. The auxiliary circuit is electrically connected to the wiring terminal, and is electrically connected to the main control system and the auxiliary circuit of the adjacent supporting base through the wiring terminal; the gas monitoring device The device includes a detection ring, a bearing column, an air environment monitoring mechanism, and an auxiliary circuit. The bearing column is a hollow columnar structure with an axis perpendicular to the horizontal plane, and its upper end surface is hinged to the outer surface of a detection ring through a ratchet mechanism. The axis of the detection ring is perpendicular to and intersects with the axis of the bearing column. The detection ring includes a guide tube with a length of at least 1.5 times the diameter of the bearing column. The guide tubes are coaxially distributed and two adjacent guide tubes are connected to each other through at least three ribs. The air environment monitoring mechanisms are several, respectively embedded in the inner surface of each guide tube and evenly distributed around the axis of the guide tube. The air quality sensors are connected in parallel and electrically connected to the auxiliary circuit respectively. The auxiliary circuit is embedded in the bearing column and electrically connected to the main control system. ; 2. A coal mine goaf submerged air-dried coal spontaneous combustion monitoring system according to claim 1, characterized in that: The pressure monitor includes an auxiliary circuit, a guide rail, an elastic hinge, a load-bearing spring, a tension sensor, a test bench, a pressure sensor, a pulley, a universal hinge, a slider and an elastic telescopic rod. The guide rails are several and distributed along the axis of the goaf and connected to the top plate of the goaf. The front end and rear end faces of the guide rails are connected to a load-bearing spring, and the guide rails and the load-bearing spring are hinged by an elastic hinge. The load-bearing springs connected to two adjacent guide rails are connected by a tension sensor, and the load-bearing spring and the tension sensor are coaxially distributed. The test bench is a rectangular cross-section. shaped plate structure, the upper end face of which is hinged to the slider through a universal hinge and forms an angle of 0°-60° with the top plate of the goaf, the slider is also slidably connected to the guide rail, the upper end face of the detection platform is also hinged to two elastic telescopic rods through an elastic hinge, the axis of the elastic telescopic rod forms an angle of 30°-90° with the upper end face of the detection platform, the upper end face of the elastic telescopic rod is also connected to 1-2 pulleys through a pressure sensor, and the pulley is abutted against and slidably connected to the top plate of the goaf, the auxiliary circuit is also embedded in the detection platform, and is electrically connected to the pressure sensor, tension sensor and main control system respectively.

3. The system for monitoring spontaneous combustion of air-dried coal in water-logged goaf of underground coal mine according to claim 1, characterized in that: The auxiliary circuit is a circuit system based on any one of DSP and FPGA chips, and the auxiliary circuit is further provided with a charge and discharge control circuit, an overload protection circuit and a driving battery pack.

4. The system for monitoring spontaneous combustion of air-dried coal in water-logged goaf of underground coal mines according to claim 1 is characterized by: The main control system is a data server based on big data, and the main control system is also equipped with several control terminals based on PC computers and mobile intelligent communication terminals.

5. The method for operating a system for monitoring spontaneous combustion of air-dried coal in water-logged goaf areas of underground coal mines according to claim 1, characterized in that: The operation method of the spontaneous combustion monitoring system for water-soaked air-dried coal in the goaf of an underground coal mine comprises the following steps: S1, system assembly, the axis sets the main control system in the coal mine machine room, and then sets a plurality of pressure monitors on the roof of the goaf area, sets at least one pressure monitoring mechanism in the supporting rock pile in each collapsed area of ​​the goaf, sets at least one coal sample temperature monitor in each coal residue area of ​​the goaf, sets a water body monitoring mechanism in the residual water body of the goaf, and sets a plurality of gas monitoring devices in sequence along the exhaust direction of the goaf, and sets a coal sample temperature monitor, a water body monitoring mechanism, a pressure monitoring mechanism, and a gas monitoring mechanism. A device and a pressure monitor constitute a detection group, and the detection groups are connected in parallel and distributed along the axis of the goaf, and the distance between two adjacent detection groups is not less than 10 meters; finally, the coal sample temperature monitor, water monitoring mechanism, pressure monitoring mechanism, gas monitoring device, and pressure monitor of each detection group are connected to the main control system respectively, and an independent communication address is assigned to each detection group to complete the system configuration; S2, data acquisition, after completing step S1, the main control system drives each detection group to run at the same time. When the detection group is running: Coal sample temperature monitor: detects the internal temperature of the coal accumulation temperature, and assists in the detection of the coal. Auxiliary detection of the internal structure pressure of the coal, and the natural risk of the coal is determined based on the temperature and pressure of the coal. Pressure monitoring mechanism: detect the internal pressure of the rock pile that collapses in the goaf and supports the operation at the top of the goaf, and assist in obtaining the pressure value of the coal in the goaf, and judge the natural risk of the coal according to the pressure value of the coal in the goaf; pressure monitor: detect the deformation amount of the goaf roof when it collapses and the pressure generated by the deformation, and cooperate with the pressure monitoring mechanism to further detect and determine the pressure value of the coal in the goaf, so as to assist in judging the natural risk of the coal; water monitoring mechanism: residual in the goaf The depth and quality of water bodies are detected. On the one hand, the oxidation state of the coal residue is indirectly collected and analyzed by detecting suspended and dissolved matter in the water body. On the other hand, the water volume in the goaf is judged by the depth of the overflow water body, and the natural risk of the coal residue in the goaf is indirectly judged based on the water volume. Gas monitoring device: the concentration of oxygen, carbon monoxide, methane and carbon dioxide in the air environment of the goaf, and the natural risk of the coal residue is judged based on the gas composition and content. S3, spontaneous combustion judgment, according to the parameters collected in step S2, the main control system summarizes and analyzes the data collected by each detection group in step S2, so as to obtain the registration and evaluation results of the spontaneous combustion risk of the coal sample.

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