Extraction system and extraction method for corner gas block on coal face

Abstract

The invention discloses a coal face upper corner gas block extraction system which comprises an advancing mechanism, an extraction mechanism and a control mechanism. The extraction mechanism realizes goaf state monitoring and gas extraction; and the control mechanism controls the received signal to perform data analysis and processing, and reasonably issues an extraction instruction. The invention further discloses a coal face upper corner gas block extraction method. The method comprises the steps that coal face goaf extraction parameters are determined; installing an extraction system on site; starting each electric appliance part; completing information collection and processing to obtain an analysis result; a related action instruction is given according to the analysis result, adjustment of the extraction position is completed, and then gas extraction of the current area is completed; when the gas concentration of the goaf meets the safety standard, it is confirmed that extraction is completed. The invention belongs to the technical field of coal mine gas extraction and solves the problems that existing extraction equipment is unreasonable in structure and cannot extract gas in time.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of coal mine gas extraction, and relates to a gas block extraction system for an upper corner of a coal mining face. BACKGROUND

[0002] Article 498 of Coal Mine Safety Regulations stipulates that the gas alarm concentration of the return air corner of the coal mining face is greater than or equal to 1%. In recent years, the production scale of the mine is continuously developing towards large-scale and scale, and under the influence of the mining capacity improvement and the adjustment of the ventilation mode, the upper corner of the working face is prone to gas overrun problems under the interference of the superimposed mining effect, which hides hidden dangers for the safety production of the mine.

[0003] The coal mine gas extraction is a fundamental measure for preventing and treating coal mine gas disasters, and is a reliable means for preventing gas overrun, gas explosion and other disasters. At present, the most commonly used technical measures for the gas extraction of the upper corner of the coal mining face are the pipe insertion extraction and the pipe embedding extraction, but in the field application, the pipe insertion extraction has a small gas control area of the goaf and poor extraction effect, and the pipe embedding extraction embeds the pipeline in the goaf, which causes material waste, and at the same time, the range of the spontaneous combustion three zones is expanded due to the goaf extraction, which increases the difficulty of the mine fire prevention and extinguishing work.

[0004] Therefore, it is urgent to develop a gas block extraction system and method for the upper corner of the coal mining face to solve the problems existing in the safety production of the mine. SUMMARY

[0005] The application aims to provide a gas block extraction system for the upper corner of the coal mining face, and solves the problems of the unreasonable structure of the extraction equipment and the untimely extraction of gas in the prior art.

[0006] Another object of the application is to provide a gas block extraction method for the upper corner of the coal mining face, and solve the problems of the unreasonable technical measures and the poor gas control effect of the upper corner of the mining face in the prior art.

[0007] The technical solution adopted by the application is a gas block extraction system for the upper corner of the coal mining face, which comprises a traveling mechanism, an extraction mechanism and a control mechanism, the traveling mechanism realizes the walking movement of the whole system, the extraction mechanism realizes the goaf state monitoring and gas extraction, the extraction dry pipe in the extraction mechanism is connected with the working face extraction pipeline to realize gas transportation, and the control mechanism controls each functional unit, receives signals for data analysis and processing, and reasonably issues extraction instructions.

[0008] Another technical solution adopted by the application is a gas block extraction method for the upper corner of the coal mining face, which utilizes the above-mentioned gas block extraction system for the upper corner of the coal mining face and is implemented according to the following steps: Step 1: determining the extraction parameters of the goaf of the coal mining face; Step 2: installing the extraction system on site; Step 3: starting the various electrical components, unfolding the travelling mechanism, performing inspection and collecting relevant data information and image information; Step 4: the control mechanism completes information collection and processing, and obtains analysis results; Step 5: the control mechanism gives relevant action instructions according to the analysis results, the travelling mechanism completes adjustment of the extraction position, and the extraction mechanism completes gas extraction in the current area; Step 6: when the gas concentration in the goaf is reduced by extraction and meets the safety standard, it is confirmed that the extraction is completed, and the relevant components are withdrawn.

[0009] The beneficial effects of the present application are as follows: 1) the extraction system of the present application can automatically monitor the gas information in the goaf, carry out accurate extraction of the goaf according to the gas distribution, the control mechanism can reasonably control the extraction range and extraction negative pressure, realize accurate treatment of the goaf gas, and the goaf inspection assembly can perform real-time inspection on the internal conditions of the goaf and timely adjust the extraction parameters. 2) the extraction method of the present application, by establishing a model, on-site inspection and analysis, according to the internal conditions of the goaf, the corresponding extraction parameters are taken, and the problem of goaf gas extraction is effectively solved. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 is a schematic diagram of the overall structure of the extraction system of the present application; Figure 2 is a structural block diagram of the travelling mechanism in the extraction system of the present application; Figure 3 is a structural block diagram of the extraction mechanism in the extraction system of the present application; Figure 4 is a structural block diagram of the goaf extraction assembly in the extraction system of the present application; Figure 5 is a structural block diagram of the control mechanism in the extraction system of the present application.

[0011] In the figure, 1. traveling mechanism, 2. extraction mechanism, 3. control mechanism, 11. universal wheel, 12. support column, 13. traction assembly, 14. hydraulic prop, 15. top support plate, 16. sealing assembly, 161. compressed air pipe, 162. electric control valve one, 163. air bag, 17. base; 21. extraction main pipe, 22. extraction branch pipe, 23. goaf inspection assembly, 231. multi-parameter inspection instrument, 232. three-dimensional laser scanner, 233. three-dimensional rotating camera, 24. goaf extraction assembly, 241. air suction head, 242. guide motor, 243. electric control valve two; 31. information acquisition unit, 32. traveling control unit, 33. extraction control unit, 34. network cable, 35. power cable, 36. communication optical cable, 37. explosion-proof box, 38. electrical cabinet, 4. industrial ring network switch. DETAILED DESCRIPTION

[0012] The application will be described in detail below with reference to the drawings and specific embodiments.

[0013] Referring to Figure 1 , the structure of the coal mining face upper corner gas block extraction system of the application is composed of a traveling mechanism 1, an extraction mechanism 2 and a control mechanism 3. The traveling mechanism 1 mainly realizes the walking movement of the whole system. The extraction mechanism 2 mainly realizes the goaf state monitoring and gas extraction. The extraction main pipe 21 in the extraction mechanism 2 is connected with the working face extraction pipeline to realize gas transportation. The control mechanism 3 controls each functional unit, receives signals for data analysis and processing, and reasonably issues extraction instructions.

[0014] Referring to Figure 2 , the structure of the traveling mechanism 1 is composed of a base 17 as a support foundation, a set of universal wheels 11 installed on both sides of the base 17, support columns 12 installed on the upper surface of the base 17 and capable of realizing lifting, a total of four support columns 12 jointly connected with a support truss upward, a top support plate 15 capable of realizing opening and closing arranged above the support truss, and a plurality of tracks arranged on the upper surface of the support truss for installing each monitoring instrument in the goaf inspection assembly 23. A traction assembly 13 is installed at the front of the base 17 and is fixedly connected with the hydraulic prop 14 in the working face. The traction assembly 13 itself can step in and out, and the traction assembly 13 moves together with the traveling mechanism 1 along with the movement of the hydraulic prop 14. A sealing assembly 16 is installed at the most front end of the base 17 for sealing the goaf.

[0015] The structure of the sealing assembly 16 is composed of a compressed air pipe 161. The inlet end of the compressed air pipe 161 is communicated with the mine compressed air system and is provided with an electric control valve one 162. The outlet end of the compressed air pipe 161 is communicated with an air bag 163.

[0016] The top support plate 15 is a double-layer frame capable of opening and closing, and the double-layer frame is driven to expand or fold back by a separate hydraulic device. Each layer of the frame is composed of steel pipes, and each layer of the frame is uniformly distributed with air gaps (preferably 30 cm x 30 cm). All air gaps are fully installed with metal nets, which not only satisfy the shielding effect of the falling stones above the top support plate 15, but also protect the traveling mechanism 1, the extraction mechanism 2 and the control mechanism 3 below the top support plate 15. The gas in the goaf can also flow normally through the metal nets, ensuring that the gas measured by the monitoring instrument belongs to the area.

[0017] Referring to Figure 3 , Figure 4 , the structure of the extraction mechanism 2 comprises an extraction main pipe 21 and a goaf inspection assembly 23. The outlet end of the extraction main pipe 21 is in communication with the extraction pipeline in the roadway. A plurality of extraction branch pipes 22 are installed on the extraction main pipe 21. Each extraction branch pipe 22 is provided with a set of goaf extraction assembly 24. Each set of goaf extraction assembly 24 comprises an air suction head 241, a guide motor 242 and an electric control valve 243. The air suction head 241 is arranged at the end of the extraction branch pipe 22, and the air suction head 241 is fixed at the end of the transmission shaft of the guide motor 242. The air suction head 241 is in communication with the electric control valve 243 through the guide motor 242. The electric control valve 243 is arranged in the extraction branch pipe 22 close to the extraction pipeline. Each goaf extraction assembly 24 is used for accurate extraction of different blocks in the goaf. The goaf inspection assembly 23 comprises a multi-parameter inspection instrument 231, a three-dimensional laser scanner 232 and a three-dimensional rotating camera 233. A plurality of guide rails are installed on the support truss below the top support plate 15. The multi-parameter inspection instrument 231, the three-dimensional laser scanner 232 and the three-dimensional rotating camera 233 are respectively arranged on the guide rails and move along the set paths and monitor upward through the metal nets. The goaf inspection assembly 23 is used for monitoring the state of the goaf and the gas in the goaf.

[0018] Referring to Figure 5 , the structure of the control mechanism 3 comprises an explosion-proof box 37. The explosion-proof box 37 is internally provided with a power adapter and a PLC. The PLC is configured with an interactive interface and a switch. The PLC in the explosion-proof box 37 is respectively connected with the information acquisition unit 31, the traveling control unit 32 and the extraction control unit 33 through the network cable 34. The power adapter in the explosion-proof box 37 is respectively connected with the information acquisition unit 31, the traveling control unit 32 and the extraction control unit 33 through the power supply line 35. The power adapter in the explosion-proof box 37 is connected with the electrical cabinet 38 through the power supply line 35. The electrical cabinet 38 supplies power to the whole system. The switch of the PLC is connected with the industrial ring network switch 4 through the communication optical cable 36, transmits signals to the industrial ring network of the terminal, and realizes remote monitoring and operation. The information acquisition unit 31, the travel control unit 32 and the extraction control unit 33 are signal connected with each other through the network cable 34; in addition, the information acquisition unit 31 is signal connected with the goaf inspection assembly 23 in the extraction mechanism 2, collects the monitoring information of the goaf inspection assembly 23, analyzes the monitoring information and carries out three-dimensional modeling; the travel control unit 32 is signal connected with the action component in the travel mechanism 1, controls the closed state of the sealing assembly 16, controls the lifting of the four support columns 12 and the opening and closing of the top support plate 15, controls the instruments in the goaf inspection assembly 23 to move along the respective tracks to carry out the monitoring without dead angle, controls the step operation of the traction assembly 13 to realize the pulling of the base 17 to move.

[0019] The working principle of the extraction system is as follows: 1) The travel mechanism 1 mainly provides the movement of the whole system, two universal wheels 11 are arranged on the two sides of the base 17 respectively, the base 17 is connected with the hydraulic support 14 on the working face through the traction assembly 13, and synchronous movement of the travel mechanism 1 is driven along with the movement of the hydraulic support 14; the support columns 12 capable of lifting are arranged on the two sides of the base 17 respectively, the top ends of the four support columns 12 are provided with the openable and closable top support plate 15 through the support truss, for protecting all the equipment inside the goaf extraction space; the sealing assembly 16 is installed at the front end of the base 17, the goaf is closed after the sealing assembly 16 expands, the electric control valve 162 in the sealing assembly 16 is used for controlling the gas conveying state (opening, closing and valve opening degree) of the compressed air pipe 161, the compressed air pipe 161 provides the air source for the air bag 163, see Figure 1 and Figure 2 .

[0020] 2) The extraction mechanism 2 mainly realizes the goaf state monitoring and partitioned gas extraction, the extraction main pipe 21 is communicated with the working face (tunnel) extraction pipeline, to realize the gas conveying; a plurality of extraction branch pipes 22 are additionally installed on the extraction main pipe 21, and a set of goaf extraction assemblies 24 is installed on each extraction branch pipe 22, see Figure 3 and Figure 4 .

[0021] The different regions of the goaf are precisely extracted; in the goaf inspection assembly 23, the multi-parameter inspection instrument 231 is used for continuously inspecting the gas concentration inside the goaf, the three-dimensional laser scanner 232 is used for high-speed scanning inside the goaf, complete information in the goaf is collected, and the three-dimensional rotating camera 233 is used for video collection inside the goaf.

[0022] In the gob extraction assembly 24, the electric control valve two 243 is used to control the extraction negative pressure of the suction head 241; the guide motor 242 can realize 360° rotation and extension of the suction head 241 according to the instruction of the control mechanism 3, so as to realize accurate extraction in the gob. A plurality of small suction holes are arranged on the suction head 241, so as to realize the suction of the gas in the gob. The electric connection realizes the power supply and signal interaction of each component and the control mechanism 3 through the circuit, and the electric connection includes a power supply link and a signal transmission link, which are described as follows: a) Power supply link: in the control mechanism 3, the electric cabinet 38 transmits power to the extraction control unit 33 through the explosion-proof box 37 and the power line 35, and then the extraction control unit 33 is connected to the electric control valve two 243 and the guide motor 242 through branch connection, so as to provide working power for the two, and provide switch driving power for the electric control valve two 243 and provide rotation and extension power for the guide motor 242; b) Signal transmission link: the extraction control unit 33 sends instructions to the electric control valve two 243 through the signal line, controls the switch state and opening degree, so as to adjust the extraction negative pressure; the extraction control unit 33 sends the angle rotation and extension length instructions to the guide motor 242 through the signal line, and the guide motor 242 drives the suction head 241 to realize rotation and extension, so as to realize accurate positioning of the suction head 241; the real-time opening degree, rotation angle and extension position of the electric control valve two 243 and the guide motor 242 are fed back to the extraction control unit 33 through the signal line, forming a closed loop control.

[0023] c) The extraction process realizes the flow of gas through the sealed pipeline, so as to ensure that the gas is efficiently transported from the suction head 241 to the extraction branch pipe 22, which is divided into airflow path and sealing requirement, which are described as follows: Airflow path: a plurality of small holes are arranged on the surface of the suction head 241, which directly sucks the gas in the gob; the suction head 241 is communicated with the guide motor 242 through the hollow connection pipe, and the gas enters the hollow channel of the guide motor 242 through the suction head 241; the other end of the guide motor 242 is connected with the inlet end of the electric control valve two 243 through the pipeline, and the gas flows into the electric control valve two 243 through the guide motor 242; the outlet end of the electric control valve two 243 is connected with the extraction branch pipe 22, and finally the gas is transported to the extraction pipeline of the roadway through the extraction main pipe 21; Sealing requirement: all channel connection parts are treated with sealing elements to ensure air tightness and avoid gas leakage affecting extraction efficiency or causing safety hazards.

[0024] 3) For the control mechanism 3, see Figure 5, the information acquisition unit 31, the travel control unit 32 and the extraction control unit 33 realize two-way data intercommunication through data interface and software protocol. The information acquisition unit 31 transmits the processed information to the travel control unit 32 and the extraction control unit 33 through the data bus, providing decision information. The travel control unit 32 and the extraction control unit 33 exist state feedback and collaborative control interaction. The travel control unit 32 state information, such as moving to the signal, closed signal feedback to the extraction control unit 33, to ensure the extraction assembly work in stable environment. The extraction control unit 33 sends collaborative adjustment instructions to the travel control unit 32, such as driving traction assembly 13, base 17 fine-tune position, cooperate with extraction.

[0025] The three units are connected with the related components in the extraction mechanism 2 and the travel mechanism 1 through the network cable 34 and the power cable 35, and on the other hand, through the switch in the explosion-proof box 37, they are connected with the industrial ring network switch 4 through the communication optical cable 36 (flame-retardant communication optical cable) to realize remote data interaction with the ground terminal. The specific description is as follows: The information acquisition unit 31 is connected with the extraction mechanism 2 through the network cable 34, collects the monitoring information obtained by the goaf inspection assembly 23, analyzes the monitoring information and makes three-dimensional modeling; the travel control unit 32 is connected with the travel mechanism 1 through the network cable 34, controls the closed state of the sealing assembly 16, controls the lifting of the support column 12 and the opening and closing of the top support plate 15, controls the movement of each monitoring instrument in the goaf inspection assembly 23, and controls the traction assembly 13 to pull the base 17 to move; the extraction control unit 33 has a pre-stored gas extraction model of the mine, controls the goaf extraction assembly 24 in the extraction mechanism 2 according to the analysis result of the information acquisition unit 31, adjusts the azimuth angle of the suction head 241 and the extraction parameters by changing the state of the electric control valve 243 and the guide motor 242, and realizes reasonable adjustment of the extraction parameters and the extraction position.

[0026] 4) The control mechanism 3 includes not only information processing hardware (computer related configuration), but also pre-stored information processing software, which is described as follows: a) The three-dimensional laser scanner 232 and the three-dimensional rotating camera 233 are used to obtain the shape of the goaf and the image of the goaf, and the information is transmitted to the information acquisition unit 31 to make three-dimensional simulation modeling of the goaf.

[0027] b) The multi-parameter inspection instrument 231 is used to monitor the gas concentration (methane, carbon monoxide, oxygen) in the goaf in real time, and the measurement results are transmitted to the information acquisition unit 31 to finally form a three-dimensional gas cloud chart of the goaf.

[0028] c) The display screen of the interactive interface or terminal system of the PLC displays the information inside the goaf in real time (including but not limited to the shape of the goaf, the image inside the goaf, etc.), or manually remote operation (multi-angle scanning and adjusting the angle of the image), supports historical query according to time, gas concentration warning, etc., supports report generation and export, supports generating a three-dimensional state diagram, and supports remote modification of the control parameters of the multi-parameter inspection instrument 231, the three-dimensional laser scanner 232, and the three-dimensional rotating camera 233 (such as scanning period, scanning frequency, and scanning mode).

[0029] 5) Explanation of the control signals sent by the travel control unit 32 and the extraction control unit 33.

[0030] The travel control unit 32 is connected to the travel mechanism 1 through the network cable 34, sends control signals to the base movement, support protection, and goaf sealing three types of actions, controls the extension and retraction amount of the traction assembly 13 according to the coordination requirements of the extraction control unit 33, drives the base 17 to move synchronously with the hydraulic support 14, performs fine adjustment, and ensures that the extraction assembly is aligned with the target area. The "stop command" is sent, the base 17 moves to the preset position is judged by the displacement sensor on the base 17, and the stop signal is sent to avoid overtravel. The "lifting command" is sent to the support column 12, the four support columns 12 are controlled to be lifted / sunk synchronously, the height of the top support plate 15 is adjusted to adapt to the height of the goaf roof, and the protection range is ensured to cover the extraction area. The "opening / closing command" is sent to the top support plate 15, which is controlled to be expanded / closed to prevent the top plate from being damaged by the extraction assembly. Before the travel mechanism 1 moves, the "deflation command" is sent, the electric control valve one 162 is controlled to exhaust in reverse, the air bag 163 is contracted, and the movement is avoided to be blocked. The "opening degree adjustment command" is sent to the sealing assembly 16, the opening and closing of the electric control valve one 162 and the size of the passage are adjusted, the inflation amount of the compressed air pipe 161 to the air bag 163 is controlled, the air bag 163 is inflated to seal the gap between the goaf and the working face, and the gas leakage or fresh air mixing is reduced.

[0031] The extraction control unit 33 sends control signals to the goaf extraction assembly 24 according to the analysis results of the information acquisition unit 31, realizes precise positioning and flow regulation. The "rotation angle command" is sent to the guide motor 242, the 360° rotation of the guide motor 242 is controlled, and the air suction head 241 is aligned with the gas enrichment area. The "extension length command" is sent to control the extension amount of the guide motor 242, the depth of the air suction head 241 in the goaf is adjusted, and the high-concentration gas area is ensured to be close. The "opening degree command" is sent to the electric control valve two 243, the extraction negative pressure is controlled by adjusting the valve opening, the extraction efficiency is ensured, and the spontaneous combustion of residual coal in the goaf caused by excessive negative pressure is avoided. The "on / off command" is sent, the closing signal is sent when the gas concentration is lower than the critical value, the extraction is stopped; the emergency opening signal is sent when the gas is over-limit, and the extraction is intensified.

[0032] The coal mining face upper corner gas block extraction method of the application utilizes the above-mentioned coal mining face upper corner gas block extraction system and is implemented according to the following steps: Step 1: A comprehensive method of numerical simulation, similar simulation, theoretical analysis and engineering experiment is adopted to determine the reasonable parameters (extraction negative pressure and extraction range) of the goaf extraction of the coal mining face under the conditions of taking into account the requirements of mine fire prevention and the needs of upper corner gas prevention and control, specifically as follows: Numerical simulation: Based on the geological conditions and mining parameters of the goaf, a three-dimensional flow field model is established to simulate the gas migration law under different negative pressures and extraction ranges, analyze the gas concentration distribution, flow velocity and air leakage intensity, and focus on simulating the influence of extraction negative pressure on the "combustion three zones" of the goaf to avoid the expansion of the oxidation zone caused by the influx of oxygen due to excessive negative pressure; Similar simulation: A 1:50 physical model is built in proportion to simulate the caving morphology and gas seepage characteristics of the goaf, the extraction port position and negative pressure value are changed, and the relationship between gas extraction efficiency and residual coal oxidation rate is observed; Theoretical analysis: Based on the gas migration equation and the theory of coal spontaneous combustion kinetics, the critical extraction negative pressure is calculated to obtain the minimum negative pressure, the maximum negative pressure and the extraction range calculation value; Engineering experiment: Select a typical area for trial extraction on site, arrange sensors to monitor gas concentration, negative pressure and oxygen content, compare the extraction efficiency and fire prevention effect under different parameters, and finally determine the parameters suitable for the mine; Finally, the extraction negative pressure and extraction range are determined, the extraction negative pressure includes avoiding excessive extraction of air in the low-gas area, improving the extraction efficiency in the high-gas area, and controlling the air leakage in the near-spontaneous combustion risk area. The extraction range includes the gas gathering area along the strike, avoiding the main airflow field along the inclination, and avoiding the blockage area of the goaf across the falling material along the vertical direction.

[0033] Step 2: Install the extraction system of the application on site and connect the related components: Arrange the gas block extraction system in the goaf of the working face, firmly connect the extraction main pipe 21 with the extraction pipeline laid in the roadway, and firmly connect the base 17 with the hydraulic support 14 of the working face through the traction assembly 13.

[0034] Step 3: Start each electrical component, perform inspection and collect related data information and image information: Expand the traveling mechanism 1, and the goaf inspection assembly 23 in the extraction mechanism 2 starts inspection and collects related data and image information, the support columns 12 around the base 17 are synchronously raised, the top support plate 15 is opened, and it is ensured that the related components in the system are not damaged by the falling of roof debris, the multiple parameter inspection instruments 231, three-dimensional laser scanners 232 and three-dimensional rotating cameras 233 in the goaf inspection assembly 23 continuously inspect according to the established route on their respective guide rails and collect related data and image information.

[0035] Step 4: The control mechanism 3 completes information collection and processing, and obtains analysis results: The goaf inspection assembly 23 transmits the real-time collected data and image information to the control mechanism 3 through the network cable 34. The information collection unit 31 in the control mechanism 3 records all the information and analyzes and solves these information. According to the latest information collected from the goaf, the information collection unit 31 completes three-dimensional modeling of the internal situation of the current monitored goaf.

[0036] Step 5: The control mechanism 3 gives relevant action instructions according to the analysis results. The travel control unit 32 controls the travel mechanism 1 to first complete the adjustment of the extraction position, and the extraction control unit 33 controls the goaf extraction assembly 24 in the extraction mechanism 2 to complete the gas extraction of the current area: Adjusting the extraction position: first, the travel control unit 32 controls the travel mechanism 1 to act. The travel control unit 32 receives the coordinates sent by the information collection unit 31, and sends instructions to the traction assembly 13 to control the traction assembly 13 to stretch and retract, thereby driving the base 17 to move synchronously with the hydraulic support 14. Then, the "elongation instruction" is sent to the support column 12, so that the four support columns 12 are synchronously raised, the top support plate 15 is lifted close to the roof of the goaf, the extraction position is fixed, and the falling of the roof debris is avoided; Protecting the extraction space: according to the height of the goaf, the "opening and closing instruction" is sent to the top support plate 15 to control the expansion angle and expand the protection range, so as to ensure that the goaf extraction assembly 24 and the goaf inspection assembly 23 work reliably in the protection area; Sealing the goaf: the "opening degree instruction" is sent to the electric control valve 162 of the sealing assembly 16, the air bag 163 is inflated by the compressed air pipe 161, the air bag 163 is inflated and adheres to the goaf wall, the goaf where the base 17 is located is sealed from other areas, and the mixing of fresh air or gas leakage is reduced.

[0037] Secondly, the extraction control unit 33 positions the target extraction area: the extraction control unit 33 receives the three-dimensional coordinates of the gas enrichment area generated by the information collection unit 31, and sends the rotation and / or extension instruction (or "rotation + extension instruction") to the guide motor 242; adjusting the extraction parameters: the extraction control unit 33 sends the "opening degree instruction" to the electric control valve 243, adjusts the valve opening degree according to the gas concentration, and controls the extraction negative pressure; real-time receiving of the opening degree signal and the position signal of the guide motor 242 of the electric control valve 243 feedback, and sending the correction instruction when deviating; multi-area collaborative extraction: sending instructions to the goaf extraction assemblies 24 on different extraction branch pipes 22, differentially adjusting the angle, extension length and opening degree of the electric control valve 243 of the guide motor 242 in each assembly, and avoiding mutual interference.

[0038] Step 6: When the gas concentration in the gob is reduced by extraction and meets the safety standard, it is confirmed that the extraction is completed, the related components are removed, and the next working face is entered: After the extraction operation continues for a certain period of time, the information acquisition unit 31 acquires information in real time through the gob inspection assembly 23, and the extraction control unit 33 can confirm that the gas concentration in the working face is reduced to meet the safety standard, that is, the extraction is completed; then, the travel control unit 32 issues an instruction to the travel mechanism 1, the travel mechanism 1 closes the top support plate 15, lowers the four support columns 12, and shrinks the air bag 163, and the travel mechanism 1 and the extraction mechanism 2 are restored to the initial shrinkage state; After the travel mechanism 1 is repositioned, the gas extraction of the next working face can be started, and the cycle is repeated.

[0039] The coal mining working face upper corner gas block extraction system and method has the characteristics of real-time monitoring, accurate extraction, safety warning, autonomous movement and the like, makes up the extraction efficiency problem and safety problem of the current high-yield and high-efficiency mine easy-to-self-ignite coal seam coal mining working face upper corner gas extraction, plays an important role in the gob upper corner gas control, has a good use prospect, and can be widely applied to the coal mining technical field, and provides strong support for mine safety and efficient production.

[0040] Example 1 According to the method of the present application, the coal mining working face upper corner gas block extraction system is used, and the following steps are implemented: Step 1: numerical simulation, similar simulation, theoretical analysis and engineering experiment are used to determine that the reasonable interval of the gob extraction of a certain mine coal mining working face is 20 m, and the extraction negative pressure is 7 KPa; Step 2: the extraction system of the present application is arranged in the working face gob, the initial control distance is 20 m, the extraction negative pressure is 7 KPa, and the extraction dry pipe 21 is connected with the extraction pipeline in the roadway.

[0041] Step 3: the support columns 12 around the base 17 are raised, the top support plate 15 is opened, the multi-parameter inspection instrument 231, the three-dimensional laser scanner 232 and the three-dimensional rotating camera 233 are continuously inspected on the respective guide rails according to the predetermined route.

[0042] Step 4: through the observation of the three-dimensional rotating camera 233, the gob roof is relatively complete and presents a rectangular shape, the three-dimensional laser scanner 232 scans to determine that the extraction area of the gob has a depth of 20 m, a height of 4 m and a width of 3 m, the information acquisition unit 31 receives the monitoring signals in real time and models the interior of the gob, divides the interior of the gob into 100 unit cells, and numbers and coordinates each unit cell.

[0043] Step 5: The multi-parameter inspection instrument 231 monitors the gas concentration (methane, carbon monoxide, oxygen) in the goaf in real time and transmits the monitoring results to the information acquisition unit 31 to form a methane three-dimensional cloud map, a carbon monoxide three-dimensional cloud map, and an oxygen three-dimensional cloud map respectively based on the modeling of the goaf.

[0044] Step 6: The extraction control unit 33 issues instructions to the extraction mechanism 2, and the goaf extraction assembly 24 performs block-type precise extraction on the gas enrichment area (gas concentration > 3%) according to the number and coordinates provided by the information acquisition unit 31, greatly improving the goaf gas extraction concentration and effectively controlling the upper corner gas.

[0045] Embodiment 2 According to the method of the present application, the upper corner gas block extraction system of the coal mining face is used to implement the following steps: Step 1: The reasonable extraction step distance of the goaf is determined by theoretical analysis, numerical simulation, similar simulation, and laboratory analysis.

[0046] Step 2: The extraction system of the present application is arranged in the goaf of the working face. The multi-parameter inspection instrument 231, the three-dimensional laser scanner 232, and the three-dimensional rotating camera 233 continuously inspect along the established route on the guide rail, and the modeling and precise extraction process in the goaf is omitted.

[0047] Step 3: The mine stoping face advances to the structure area, and the gas appears abnormal fluctuation. The working face upper corner gas sensor monitors that the gas concentration is close to 0.7%, and the multi-parameter inspection instrument 231 monitors that the variation range of the methane gas concentration in the goaf increases. The gas concentration near the upper corner position exceeds the set critical value. The information acquisition unit 31 timely transmits the information to the extraction mechanism, and the extraction mechanism 2 increases the extraction negative pressure by 3KPa by adjusting the guide motor 242 and the electric control valve two 243 of the goaf extraction assembly. The extraction is focused on the gas enrichment area (concentration exceeding 3%), and the control mechanism 3 transmits the gas abnormal information to the ground technical personnel through the industrial ring network.

[0048] Step 4: The technical personnel comprehensively analyze and judge that the main reason for the gas source is that the sudden increase of the gas in the structure area flows into the goaf through the return air flow, causing the increase of the upper corner gas concentration. The operator immediately disposes, reduces the coal cutting speed, adjusts the air bag pressure in the sealing assembly 16 to ensure the sealing of the goaf, and increases the extraction intensity of the goaf extraction assembly 24. The multi-parameter inspection instrument 231 continuously monitors the gas condition in the goaf and timely issues adjustment instructions.

[0049] Step 5: Through reasonable measures, the multi-parameter inspection instrument 231 monitors that the methane gas concentration in the goaf gradually decreases to the critical value range, and the working face upper corner gas sensor monitors that the gas concentration decreases to 0.4%.

[0050] Embodiment 3 According to the method of the present application, the gob of a certain mine is extracted and controlled by using the aforementioned gas block extraction system in the upper corner of the coal mining face, and the following steps are implemented: Step 1: Through comprehensive methods such as theoretical analysis, numerical simulation, similar simulation and laboratory analysis, the reasonable extraction step distance of the gob is determined.

[0051] Step 2: The extraction system of the present application is arranged in the gob of the working face. The multi-parameter inspection instrument 231, the three-dimensional laser scanner 232 and the three-dimensional rotating camera 233 continuously inspect along the established route on their respective guide rails, and the modeling and accurate extraction process in the gob is omitted.

[0052] Step 3: When the multi-parameter inspection instrument 231 detects that the carbon monoxide gas concentration and the oxygen concentration in the gob exceed the set critical value, the information acquisition unit 31 timely transmits the information to the extraction mechanism 2, and the extraction mechanism 2 reduces the extraction negative pressure by 5KPa and reduces the extraction range by 5m by adjusting the guide motor 242 and the electric control valve two 243 of the gob extraction assembly 24. The control mechanism 3 transmits the abnormal information to the technical personnel on the ground through the industrial ring network.

[0053] Step 4: The technical personnel comprehensively analyze and judge the spontaneous combustion condition of the coal seam in the gob, and prepare the fire prevention and extinguishing scheme. The multi-parameter inspection instrument 231 continuously monitors the gas condition in the gob, the closed assembly 16 adjusts the air pressure of the air bag to ensure the sealing of the gob, and the extraction negative pressure is adjusted to reduce the air pressure difference between the inside and outside of the gob, thereby reducing the air leakage in the gob.

[0054] Step 5: Through reasonable measures, the multi-parameter inspection instrument 231 monitors that the carbon monoxide gas concentration and the oxygen concentration in the gob gradually recover to the critical value range, and the system starts the modeling and accurate extraction in the gob again.

[0055] Embodiment 4 According to the method of the present application, the following steps are implemented by using the aforementioned gas block extraction system in the upper corner of the coal mining face: Step 1: For the coal mining face with fault structure in a certain mine, a gob gas migration model with fault influence is established by using numerical simulation combined with field detection, the extraction step distance is determined to be 15m, the initial extraction negative pressure is 5KPa, and a 20m range near the fault is designated as the key monitoring area.

[0056] Step 2: When the extraction system is arranged in the working face, two groups of gob inspection assemblies are additionally arranged at 5m on both sides of the fault to ensure real-time monitoring of abnormal gas seepage of the fault zone; when the extraction main pipe is connected with the roadway extraction pipeline, a reinforced sealing interface is used to prevent gas leakage under high negative pressure.

[0057] Step 3: During system operation, the three-dimensional laser scanner 232 detects that the goaf near the fault has an irregular collapse shape, forming a local gas accumulation space (height 2.5 m, width 4 m); the multi-parameter inspection instrument 231 shows that the methane concentration in this area reaches 4.2%, far exceeding the critical value.

[0058] Step 4: The information acquisition unit 31 superimposes and analyzes the gas data of the fault area with the three-dimensional model, and the extraction control unit 33 issues instructions to the goaf extraction assembly 24 in the corresponding area: the guide motor 242 rotates to the direction of the fault inclination of 30°, the telescopic length increases by 1.2 m, and the center of the accumulation area is aligned; the opening of the electric control valve two 243 is adjusted to 80%, and the extraction negative pressure is increased to 8 KPa.

[0059] Step 5: After 30 minutes of continuous extraction, the multi-parameter inspection instrument 231 monitors that the methane concentration in the fault area decreases to 1.8%, and the upper corner gas sensor shows that the concentration stabilizes at 0.6%; the extraction control unit 33 gradually adjusts the negative pressure back to 5 KPa, maintains normal extraction, and ensures that the gas in the fault zone does not accumulate again.

[0060] Example 5 According to the method of the present application, using the aforementioned upper corner gas block extraction system of the coal mining face, the following steps are implemented: Step 1: According to the characteristics of the roof collapse and easy falling of the goaf in a certain mine, the protection parameters of the extraction system are determined through similar simulation experiments: the top support plate 15 needs to cover a range of 1.5 m above the extraction assembly in the expansion angle, and the lifting response time of the support column 12 does not exceed 10 seconds to quickly respond to roof falling.

[0061] Step 2: When installing the extraction system, wear-resistant steel plates are added to the surface of the top support plate 15, and buffer springs can be installed on the top surface of the top support plate 15; Step 3: After the system is started, the three-dimensional rotating camera 233 transmits the roof image in real time, and the information acquisition unit 31 identifies that a piece of about 0.3 m³ of rubble is about to fall 0.8 m away from the extraction assembly, and immediately issues a warning to the travel control unit 32.

[0062] Step 4: The travel control unit 32 synchronously executes the protection instructions: the support column 12 is raised by 0.5 m within 5 seconds, and the top support plate 15 is quickly expanded to the maximum angle to form a protective barrier; at the same time, the extraction control unit 33 suspends extraction in this area, and the guide motor 242 drives the air suction head 241 to retract into the protection range.

[0063] Step 5: After the rock falls to the top support plate 15, the buffer spring effectively absorbs the impact force, and the system has no component damage; after the top support plate 15 is stable, the travel control unit 32 controls the support column 12 to fall back and the top support plate 15 to reset, the extraction control unit 33 restarts the extraction, and the guide motor 242 repositions to the original extraction point, and the extraction parameters are restored to the set values (negative pressure 6 KPa, extraction range 3 m x 2 m).

[0064] Example 6 According to the method of the present application, the gas extraction system in the upper corner of the coal mining face is used according to the following steps: Step 1: According to the mining progress plan of the mine, the gas migration law during the advance of the working face is calculated by theoretical analysis: when the daily advance of the working face is 2.5 m, the gas enrichment zone in the goaf will migrate 0.8 m / day to the deep part of the goaf, and the extraction area needs to be adjusted synchronously.

[0065] Step 2: When the extraction system is deployed, a set of movable extraction branch pipes 22 are arranged on the extraction main pipe 21 at intervals of 5 m, each set of extraction branch pipes 22 is equipped with an independent goaf extraction assembly 24, and an extraction zone along the strike is formed.

[0066] Step 3: When the working face advances to the 5th day, the goaf inspection assembly 23 inspects according to the preset route and finds that the gas concentration in the original extraction area (30 m away from the working face) decreases to 1.2%, while a new enrichment zone (methane concentration 3.5%) appears at a depth of 35 m, and it is in a continuous distribution state.

[0067] Step 4: The information acquisition unit 31 matches and analyzes the gas migration data with the advance progress to generate a dynamic extraction area adjustment scheme; the travel control unit 32 controls the traction assembly 13 to move the base 17 forward with the hydraulic support 14 by 5 m synchronously, and the support column 12 is automatically adjusted to 2.3 m according to the new position of the roof height.

[0068] Step 5: The extraction control unit 33 coordinates the cooperative action of multiple goaf extraction assemblies 24: closes the electric control valve two 243 of the original 30 m extraction branch pipe 22, and opens the extraction assembly of the 35 m branch pipe; the guide motors 242 in the left 3 groups of extraction assemblies are uniformly rotated by 15°, and the guide motors 242 in the right 2 groups of extraction assemblies are rotated by -10°, forming a fan-shaped extraction area covering the migrated enrichment zone; the extraction negative pressure of each assembly is set to 6-7.5 KPa according to the concentration difference, realizing differential and accurate extraction.

[0069] Step 6: Continuous monitoring shows that the multi-region cooperative extraction makes the gas concentration in the goaf controlled below 1.5% and the gas concentration in the upper corner stable at 0.5%, meeting the safety requirements for continuous advance of the working face.

Claims

1. The gas extraction system for the upper corner of the coal mining face is characterized by: The system comprises three parts: a travelling mechanism (1), an extraction mechanism (2) and a control mechanism (3). The travelling mechanism (1) realizes the movement of the entire system; the extraction mechanism (2) realizes goaf status monitoring and gas extraction. The extraction main pipe (21) in the extraction mechanism (2) is connected to the extraction pipeline of the working face to realize gas transportation; the control mechanism (3) controls each functional unit, receives signals for data analysis and processing, and reasonably issues extraction instructions.

2. The coal mining face corner gas block extraction system according to claim 1 is characterized in that: The structure of the traveling mechanism (1) is as follows: it includes a base (17), universal wheels (11) are respectively installed on both sides of the base (17), liftable support columns (12) are respectively installed on both sides of the upper surface of the base (17), a total of four support columns (12) are connected upwardly to a supporting truss, a top supporting plate (15) that can be opened and closed is provided above the supporting truss, and a plurality of tracks are provided on the upper surface of the supporting truss; a traction assembly (13) is installed at the front of the base (17), the traction assembly (13) is fixedly connected to the hydraulic support (14) in the working surface, the traction assembly (13) can be stepped and retracted, and the traction assembly (13) drives the traveling mechanism (1) to move together with the movement of the hydraulic support (14); a sealing assembly (16) is installed at the front end of the base (17).

3. The coal mining face corner gas block extraction system according to claim 2 is characterized in that: The structure of the enclosed component (16) is that it includes a compressed air pipe (161), the inlet end of the compressed air pipe (161) is connected to the mine compressed air system and is provided with an electric control valve (162), and the outlet end of the compressed air pipe (161) is connected to the air bag (163).

4. The coal mining face corner gas block extraction system according to claim 1 is characterized in that: The structure of the extraction mechanism (2) is that it includes an extraction main pipe (21) and a goaf inspection component (23). The outlet end of the extraction main pipe (21) is connected to the extraction pipeline in the tunnel. A plurality of extraction branches (22) are installed on the extraction main pipe (21). Each extraction branch pipe (22) is provided with a set of goaf extraction components (24); each set of goaf extraction components (24) includes an air suction head (241), a guide motor (242), and an electric control valve 2 (243). The air suction head (241) is provided at the very end of the extraction branch pipe (22), and the air suction head (241) is fixed to the end of the transmission shaft of the guide motor (242). The air suction head (241) is connected to the electric control valve 2 (243) through the guide motor (242). The electric control valve 2 (243) is provided in the extraction branch pipe (22) close to the extraction pipeline.

5. The coal mining face corner gas block extraction system according to claim 4 is characterized in that: The goaf inspection component (23) includes a multi-parameter inspection instrument (231), a three-dimensional laser scanner (232), and a three-dimensional rotating camera (233). A plurality of guide rails are installed on the support truss below the top support plate (15), and the multi-parameter inspection instrument (231), the three-dimensional laser scanner (232), and the three-dimensional rotating camera (233) are respectively moved and set on their respective guide rails.

6. The coal mining face corner gas block extraction system according to claim 1, characterized in that: The structure of the control mechanism (3) is as follows: it includes an explosion-proof box (37), a power adapter and a PLC are provided inside the explosion-proof box (37), the PLC is configured with an interactive interface and a switch, the PLC in the explosion-proof box (37) is respectively connected to the information acquisition unit (31), the travel control unit (32), and the extraction control unit (33) through a network cable (34); the power adapter in the explosion-proof box (37) is respectively electrically connected to the information acquisition unit (31), the travel control unit (32), and the extraction control unit (33) through a power line (35); the power adapter in the explosion-proof box (37) is connected to the electrical cabinet (38) through the power line (35), and the PLC switch is externally connected to the industrial ring network switch (4) through a communication optical cable (36).

7. A method for extracting gas blocks from the upper corners of a coal mining face, using the system for extracting gas blocks from the upper corners of a coal mining face according to any one of claims 1 to 6, characterized in that: Follow these steps to implement: Step 1: Determine the extraction parameters of the goaf of the coal mining face; Step 2: Install the extraction system on site; Step 3: Start each electrical component, unfold the travel mechanism (1), conduct inspections and collect relevant data and image information; Step 4: The control mechanism (3) completes information collection and processing and obtains analysis results; Step 5: The control mechanism (3) gives relevant action instructions based on the analysis results, the travel mechanism (1) completes the adjustment of the extraction position, and the extraction mechanism (2) then completes the gas extraction in the current area; Step 6: When the gas concentration in the goaf is reduced by extraction and meets the safety standards, confirm that the extraction is completed and remove the relevant components.

8. The method for extracting gas blocks in the upper corner of a coal mining face according to claim 7, characterized in that: In step 1, a comprehensive approach of numerical simulation, similarity simulation, theoretical analysis, and engineering experiments is used. Taking into account the requirements of mine fire prevention and extinguishing and the need for upper corner gas prevention and control, the specific process is as follows: Numerical simulation: Based on the geological conditions and mining parameters of the goaf, a three-dimensional flow field model is established to simulate the gas migration pattern under different negative pressures and extraction ranges, and analyze the gas concentration distribution, flow velocity, and air leakage intensity; Similarity simulation: Build a 1:50 physical model to simulate the collapse morphology and gas seepage characteristics of the goaf, change the location of the extraction port and the negative pressure value, and observe the relationship between gas extraction efficiency and the oxidation temperature rise rate of the residual coal; Theoretical analysis: Based on the gas migration equation and coal spontaneous combustion dynamics theory, the critical drainage negative pressure is calculated to obtain the minimum negative pressure, maximum negative pressure, and drainage range calculation values; Engineering experiment: Conduct trial extraction in a typical area on site, deploy sensors to monitor gas concentration, negative pressure, and oxygen content, compare extraction efficiency and fire prevention and extinguishing effects under different parameters, and determine the parameters; Finally, the extraction negative pressure and extraction range are determined. The extraction negative pressure includes low-gas areas to avoid excessive air extraction, high-gas areas to improve extraction efficiency, and near-spontaneous combustion risk areas to control air leakage; the extraction range includes areas where gas is prone to accumulate along the strike, avoiding the mainstream ventilation field along the dip, and avoiding blockage of fallen objects across the goaf in the vertical direction.

9. The method for extracting gas blocks in the upper corner of a coal mining face according to claim 7, characterized in that: In step 4, the specific process is: The goaf inspection component (23) transmits the real-time collected data and image information to the control mechanism (3) via the network cable (34). The information collection unit (31) in the control mechanism (3) records all the information and analyzes and solves the information. Based on the latest information collected about the goaf, the information collection unit (31) completes three-dimensional modeling of the internal situation of the currently monitored goaf.

10. The method for extracting gas blocks from the upper corner of a coal mining face according to claim 7, characterized in that: In step 5, the specific process is: Adjusting the extraction position: First, the travel control unit (32) controls the movement of the travel mechanism (1), the travel control unit (32) receives the coordinates sent by the information acquisition unit (31), and the travel control unit (32) sends a command to the traction component (13) to control the traction component (13) to extend and retract, driving the base (17) to move synchronously with the hydraulic support (14); then, a command is sent to the support column (12), so that the four support columns (12) are raised synchronously, and the top support plate (15) is raised close to the top plate of the goaf; Protecting the extraction space: according to the height of the goaf, issuing an expansion command to the top support plate (15) to control its expansion angle; Sealing the goaf: sending an opening instruction to the electric control valve 1 (162) of the sealing component (16), controlling the air pressure pipe (161) to inflate the air bag (163), so that the air bag (163) expands and fits the rock wall of the goaf; Secondly, the extraction control unit (33) locates the extraction target area: the extraction control unit (33) receives the three-dimensional coordinates of the gas-rich area generated by the information acquisition unit (31), and the extraction control unit (33) issues a rotation and / or extension instruction to the guide motor (242); adjusts the extraction parameters: the extraction control unit (33) issues an opening instruction to the electric control valve 2 (243), adjusts the valve opening according to the gas concentration, and controls the extraction negative pressure; receives the opening signal feedback from the electric control valve 2 (243) and the position signal of the guide motor (242) in real time, and issues a correction instruction when there is deviation; multi-area coordinated extraction: sends instructions to the extraction components (24) of the goaf on different extraction branches (22), and differentially adjusts the angle, extension length and opening of the guide motor (242) and the electric control valve 2 (243) in each component to avoid mutual interference.

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