A visualized simulation device and method for coal and gas outburst in stone gate uncovering coal

Abstract

The application provides a visualized simulation experiment device and method for coal and gas outburst in stone gate coal uncovering, and belongs to the technical field of stone gate coal uncovering. The device simulates a gas-containing coal seam by using a gas bag filled with similar materials of a coal seam, uses an acrylic plate with good perspective as an observation plate and light-transmissive rock stratum materials, combines a light source and a high-speed camera to realize visualized simulation experiment, can measure various indexes of the coal and gas outburst process during the stone gate coal uncovering, realizes visualized quantitative simulation experiment, and provides an experimental basis for studying the outburst mechanism and process of the coal and gas in the stone gate coal uncovering and for proposing targeted outburst prevention measures.

Description

Technical Field

[0001] This invention belongs to the field of coal mine underground rock gate coal exposure technology, specifically relating to a visual simulation experimental device and method for coal and gas outburst in rock gate coal exposure. Background Technology

[0002] As an important roadway in underground coal mining, the excavation of the stone gate will change the bearing structure and gas occurrence state of the coal and rock strata. Under the combined effects of ground stress, gas pressure and tunneling activities, the gas-bearing coal seam is prone to coal and gas outbursts, causing serious safety accidents and posing a great threat to the safe and efficient production of the mine and the life and health of the workers.

[0003] Accurately assessing coal and gas outburst conditions and implementing effective prevention measures during coal seam exposure in rock face mining is crucial for ensuring safe production. Coal mining enterprises primarily explore various outburst prevention methods to achieve optimal results and ensure safe exposure and passage through the coal seam. Researchers focus on the rock mechanics mechanisms of coal and gas outbursts during rock face mining, while simulation experiments more closely related to practical engineering are relatively lacking. Most existing experimental equipment can only explore the mechanisms of coal and gas outbursts during rock face mining from specific aspects, such as coal seam mechanical properties and gas pressure. Additionally, while educational experimental devices can demonstrate the coal and gas outburst process to some extent, their educational value outweighs their research value, lacking quantitative research methods for coal and gas outbursts.

[0004] Chinese patent ZL201110324127.5 discloses a coal and gas outburst simulation test system during coal seam exposure in a rock face. Although it can simulate coal and gas outbursts during coal seam exposure in a rock face to a certain extent, it is difficult to intuitively show the process of coal seam exposure and disaster caused by rock face exposure due to its large box size and the large amount of experimental materials required. In addition, it is complicated to install because it needs to set up diaphragms and other structures at the gap. Summary of the Invention

[0005] To address the aforementioned problems in existing technologies, this invention provides a visual simulation experimental device and method for coal and gas outbursts during coal mine exposure, aiming to achieve quantitative and visual research on the coal and gas outburst process during coal mine exposure and improve the researchability of coal and gas outbursts in underground coal mines.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A visual simulation experimental device for coal and gas outbursts in a tunnel is disclosed. The device includes a frame structure, a tunneling device, a monitoring device, experimental materials, and a controller. The frame structure comprises an experimental platform base, vertical beams, horizontal beams, a hydraulic loading head, protective beams, an observation panel, a ventilation device, and an inflation device. The vertical beams are located on the left and right sides, with their bottom ends fixed to the experimental platform base and their top ends fixedly connected via the horizontal beams. The middle or lower parts of the front and rear sides of the vertical beams are respectively fixedly connected via protective beams. The vertical beams on the left and right sides, together with the protective beams on the front and rear sides, form an accommodating space for accommodating and positioning square observation windows with upper and lower openings. The structure of the square observation window is formed by four transparent observation panels integrated into one piece, with its bottom connected to the experimental platform base and its top covered by a square plate-like crossbeam. Several hydraulic loading heads are installed at the bottom of the crossbeam to apply pressure to the experimental material to simulate geological stress. Exhaust fans are also installed on the left and right sides of the bottom of the crossbeam near the vertical beam. An air extraction hole is provided on the upper part of the experimental platform base. Both the exhaust fans and the air extraction hole are connected to a ventilation device through exhaust pipes. An inflation device is connected to the interior of the accommodating space through pipes. Both the ventilation device and the inflation device are located outside the accommodating space. The experimental material is placed inside the square observation window structure.

[0008] Preferably, the tunneling device includes a tunneling drill bit and a gangue transport device. The tunneling drill bit is mounted on a small spiral drilling robot, which drives the tunneling drill bit to drill. The small spiral drilling robot is connected to a controller via a control signal line, and the controller controls its tunneling.

[0009] Preferably, the gangue transport device includes a conveyor belt, conveyor belt pulleys, and tension springs. The conveyor belt is wound around the small spiral drilling robot and the small spiral drilling robot provides the conveying power for the conveyor belt. At least two conveyor belt pulleys are provided, and the tension spring is located between the two conveyor belt pulleys. The connection point between the tension spring and the conveyor belt forms a triangular relationship with the two conveyor belt pulleys on both sides.

[0010] Preferably, the monitoring device includes displacement measuring points, stress sensors, air pressure sensors, displacement measuring devices, and high-speed cameras. The displacement measuring points are evenly arranged on the front and back surfaces of the experimental material, the stress sensors are arranged on the top plate, bottom plate, and coal seam of the simulated coal seam, the air pressure sensors are set at the outlet of the air filling device, and the high-speed cameras are set on the front and back sides of the frame structure for recording through the observation plate.

[0011] Preferably, the experimental materials include rock strata simulation materials and coal seam simulation materials. The rock strata simulation materials are made by mixing sand, gypsum, calcium carbonate and other materials in a certain proportion. The coal seam simulation materials are made by mixing sand, gypsum, calcium carbonate, dyeing ink and other materials in a certain proportion. The coal seam simulation materials are encased in an airbag to form a closed strip-shaped coal seam. The gas pressure in the airbag is pressurized and controlled by an external inflation device.

[0012] Preferably, the rock strata simulation material and the coal seam simulation material are set up in a way that the coal seam is laid at an angle.

[0013] As a further preferred embodiment, optical fiber material is added to the rock strata simulation material, making the resulting rock strata simulation material a light-transmitting material; even more preferably, a light source is provided on the side of the frame structure opposite to the high-speed camera in the front and rear directions.

[0014] Preferably, the controller includes a display screen, a gas pressure signal, a tunneling control signal line, a stress sensor signal line, a high-speed camera control line, and a displacement signal line. The controller's function is to control the pressure and displacement of the hydraulic loading head on the frame, control the tunneling of the tunneling device, control the ventilation device, control the gas pressure in the airbag, and receive monitoring data such as stress displacement, gas pressure changes, and images.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects:

[0016] 1) The gas-bearing coal seam of the present invention is a gas-bearing airbag with an interior material similar to that of the coal seam. The process of coal and gas outburst is simulated by the destruction of the airbag by the tunneling machinery, which can more realistically reflect the occurrence of gas in the coal seam and the coal and gas outburst situation reflected is also more realistic. With the airbag, gas is not easy to leak, and gas can be replaced by air after the experiment, reducing the experimental risk. The safety of the experiment is further ensured by setting exhaust fans, air extraction holes and ventilation devices.

[0017] 2) This invention uses a transparent observation plate, a light-transmitting rock stratum simulation material, and a light source, which makes the experiment more intuitive and the collected data more accurate. Combined with stress sensors and displacement measurements, it can improve the accuracy of the experiment and realize the quantitative and visual research on coal and gas outbursts during coal seam exposure. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the coal and gas outburst simulation experimental device for Shimen coal uncovering according to the present invention;

[0019] Figure 2 This is a schematic diagram of the frame structure of the experimental apparatus of the present invention;

[0020] Figure 3This is a schematic diagram of the tunneling device structure of the experimental apparatus of the present invention;

[0021] Figure 4 This is a schematic diagram of the detection device structure of the experimental apparatus of the present invention;

[0022] Figure 5 This is a schematic diagram of the coal seam simulation material structure of the experimental apparatus of the present invention;

[0023] Figure 6 This is a schematic diagram of the controller structure of the experimental apparatus of the present invention;

[0024] In the diagram, 1-frame structure, 2-tunneling device, 3-monitoring device, 4-experimental material, 5-controller, 11-experimental platform base, 12-vertical beam, 13-horizontal beam, 14-hydraulic loading head, 15-protective beam, 16-observation board, 17-ventilation device, 18-inflation device, 21-tunneling drill bit, 22-conveyor belt, 23-conveyor belt pulley, 24-tensioning spring, 25-control signal line, 31-displacement measuring point, 32-stress sensor, 33-air pressure sensor, 34-displacement measuring device, 35-high-speed camera, 41-airbag, 42-valve, 43-coal seam similar simulation material, 51-display screen, 52-gas pressure signal line, 53-tunneling control signal line, 54-stress sensor signal line, 55-high-speed camera control line, 56-displacement signal line. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0026] like Figures 1 to 6As shown, this invention provides a visual simulation experimental device for coal and gas outburst in a rock face. The device includes a frame structure 1, a tunneling device 2, a monitoring device 3, experimental materials 4, and a controller 5. The frame structure 1 is the main body of the entire experimental device, comprising an experimental platform base 11, vertical beams 12, horizontal beams 13, a hydraulic loading head 14, protective beams 15, an observation board 16, a ventilation device 17, and an inflation device 18. The vertical beams 12 are located on the left and right sides, with their bottom ends fixedly mounted on the experimental platform base 11 and their top ends fixedly connected (removably) to the horizontal beams 13. The middle or lower parts of the front and rear sides of the vertical beams 12 are respectively fixedly connected (removably) to the protective beams 15. The vertical beams 12 on the left and right sides and the protective beams 15 on the front and rear sides together form a housing. The space is used to accommodate and position the square observation window structure with openings at the top and bottom. The square observation window structure is integrally formed by four transparent observation plates 16 on the front, back, left, and right sides. Its bottom is connected to the experimental platform base 11, and its top is covered by a square plate-shaped crossbeam 13. Several hydraulic loading heads 14 are set at the bottom of the crossbeam 13 to apply pressure to the experimental material 4 to simulate the stress of the strata. Exhaust fans are also set on the left and right sides of the bottom of the crossbeam 13 near the vertical beam 12. The upper part of the experimental platform base 11 is provided with an air extraction hole. The exhaust fans and air extraction holes are connected to the ventilation device 17 through exhaust pipes. The inflation device 18 is connected to the interior of the accommodating space through pipes. The ventilation device 17 and the inflation device 18 are both located outside the accommodating space. The experimental material 4 is placed inside the square observation window structure.

[0027] Preferably, the tunneling device 2 includes a tunneling drill bit 21 and a gangue transport device. The tunneling drill bit 21 is mounted on a small spiral drilling robot, which drives the drill bit 21 to drill. The small spiral drilling robot is connected to a controller 5 via a control signal line 25, and the controller 5 controls its tunneling. The gangue transport device includes a conveyor belt 22, conveyor belt pulleys 23, and a tension spring 24. The conveyor belt 22 is wound around the small spiral drilling robot, and the small spiral drilling robot provides the conveying power for the conveyor belt 22. At least two conveyor belt pulleys 23 are provided. The tension spring 24 is located between two conveyor belt pulleys 23, and the connection point between the tension spring 24 and the conveyor belt 22 forms a triangular relationship with the two conveyor belt pulleys 23 on both sides (not shown in the figure). In this way, on the one hand, the tension spring 24 always keeps the conveyor belt 22 taut, and on the other hand, the extension and contraction of the tension spring 24 provides the tunneling distance. Specifically, during setup, boreholes can be pre-drilled in the simulated rock strata before the tunneling device is arranged. At this point, the installed tunneling drill bit 21 is close to the simulated coal seam, so the tunneling distance provided by the spring extension and contraction is sufficient to meet the experimental requirements. The purpose of the gangue transport device is to promptly discharge gangue from the boreholes and avoid affecting the control signal line 25. The conveyor belt 22 is located below the control signal line 25. In addition, a gangue discharge chamber is provided between the upright beam 12 and the observation plate 16 on one side (e.g., the left side). The upright beam 12 adopts a plate structure, and the upright beam 12 at the corresponding position of the gangue discharge chamber protrudes outward to form a space between the upright beam 12 and the observation plate 16 (not shown in the figure). The corresponding observation plate 16 has a borehole opening, and the boreholes are arranged horizontally (e.g., horizontally from left to right, and the boreholes are staggered from the protective beam 15 during arrangement). The corresponding upright beam 12 has a control signal line lead-out hole.

[0028] Preferably, the monitoring device 3 includes a displacement measuring point 31, a stress sensor 32, a pressure sensor 33, a displacement measuring device 34, and a high-speed camera 35. The displacement measuring point 31 is evenly arranged on the front and back surfaces of the experimental material 4. The stress sensor 32 is arranged in the top plate, bottom plate, and coal seam of the simulated coal seam. The pressure sensor 33 is set at the outlet of the air filling device 18. The high-speed camera 35 is set in the front and back sides of the frame structure 1 for recording through the observation plate.

[0029] Preferably, experimental material 4 includes rock strata simulation material and coal seam simulation material, both of which are similar simulation materials. The rock strata simulation material is made by mixing sand, gypsum, calcium carbonate and other materials in a certain proportion. The specific proportion can be determined by those skilled in the art based on the actual rock strata conditions (the same below). The coal seam simulation material is made by mixing sand, gypsum, calcium carbonate, dyeing ink and other materials in a certain proportion. The coal seam simulation material is encased in an air bladder to form a closed strip-shaped coal seam. The gas pressure in the air bladder is pressurized and controlled by an external inflation device 18.

[0030] Preferably, the rock strata simulation material and the coal seam simulation material are laid in a way that the coal seam is inclined. The rock strata simulation material can be prepared in advance or formed by pressure applied by a hydraulic loading head.

[0031] As a further preferred embodiment, optical fiber material is added to the rock stratum simulation material, making the resulting rock stratum simulation material a light-transmitting material (e.g., made of translucent concrete). Further preferably, a light source is also provided on the side of the frame structure 1 opposite to the high-speed camera 35 in the front-rear direction. The advantage of this approach is that if the rock stratum is made of an opaque material, drilling tools such as boreholes and drill bits need to be positioned close to the observation plate 16 for easy observation, which limits the realism of the simulation of actual working conditions. However, by using a light-transmitting rock stratum simulation material, this limitation can be completely eliminated, and the actual situation of coal and gas outbursts can be displayed more intuitively through the combination of the light source and the camera.

[0032] Preferably, the controller includes a display screen 51, a gas pressure signal 52, a tunneling control signal line 53, a stress sensor signal line 54, a high-speed camera control line 55, and a displacement signal line 56. The controller functions to control the pressure and displacement of the hydraulic loading head on the frame, control the tunneling of the tunneling device, control the ventilation device, control the gas pressure in the airbag, and receive monitoring data such as stress displacement, gas pressure changes, and images.

[0033] As a further preferred embodiment, the present invention also provides a method for using the above experimental apparatus, specifically including the following steps:

[0034] (1) Prepare materials such as gypsum, calcium carbonate, and sand in a certain proportion to make similar simulation materials, and make similar simulation materials for rock strata and coal seams respectively;

[0035] (2) Laying out the strata on the test bench. The plane of the test bench is parallel to the direction of the stone gate. The coal seam is inclined and long. First, lay the bottom rock layer of the coal seam. Then, pour the coal seam simulation material into the air bag and compact it. Then lay it on the bottom rock layer. Then lay the top rock layer of the coal seam. Lay stress sensors at appropriate positions until all rock layers and stress sensors are laid. Arrange displacement measuring points evenly on one side of the experimental material.

[0036] (3) The inflation device is turned on by the controller, and the ventilation device is turned on at the same time. Air is drawn from the top and bottom of the experimental material to remove the gas that may be spilled during the experiment in time, and the extracted gas is safely treated; a certain amount of gas (or carbon dioxide, nitrogen) is filled into the airbag, the hydraulic loading head is adjusted to apply pressure to the material to the formation stress of the prototype, the inflation device is adjusted to make the gas pressure in the airbag reach the coal seam gas pressure of the prototype. The above formation stress and gas pressure values ​​are detected by the corresponding sensors. A displacement measuring device and a high-speed camera are installed on one side of the model.

[0037] (4) The tunneling device is controlled by the controller to start the excavation of the rock gate, and the excavated gangue is discharged through the gangue transportation device. The sensors start to collect monitoring data and the camera starts recording.

[0038] (5) When the drilling bit touches the airbag and then breaks the airtightness of the airbag, a coal and gas outburst occurs. The sensors continue to collect monitoring data and the camera records the destruction process.

[0039] (6) After the coal is exposed in the stone gate, the tunneling continues and penetrates the top / bottom rock strata until it is no longer affected by the coal seam. The tunneling is stopped. During the tunneling process, the stress, displacement, gas pressure in the rock strata, as well as the morphological changes of the rock strata roadway and coal seam are continuously monitored.

[0040] (7) After the tunnel excavation is stopped, first turn off the monitoring device, then adjust the inflation device to fill the airbag with air to squeeze out the internal gas, then turn off the ventilation pipe, remove the experimental materials, dismantle the square observation window structure and the two side beams, and clean the test table;

[0041] (8) Export the measured data such as stress, displacement, and gas pressure, as well as the video recording of the tunneling process, and organize and analyze the measurement results.

[0042] Preferably, step (3) further includes turning on a light source located on the side opposite to the high-speed camera 35 in the front-rear direction of the frame structure 1.

[0043] This invention employs a similar material simulation method to simulate the coal and gas outburst process during coal seam exposure in a rock-cut mine. An airbag filled with a similar material to the coal seam is used to simulate a gas-bearing coal seam, and the gas pressure within the airbag can be controlled. A spiral drilling robot drives a drill bit to excavate through the simulated rock strata to simulate the coal seam exposure process. When the drill bit destroys the airbag, a coal and gas outburst occurs. The entire experimental setup is designed based on plane strain problems. Stress and displacement measuring lines are arranged in the rock strata near the coal seam exposure location to monitor the stress and displacement characteristics of the rock strata during the coal and gas outburst process. A transparent acrylic plate is used as the observation panel, and the rock strata material is translucent. Visual visualization is achieved by combining a light source and a high-speed camera. The device simulates the entire process of coal seam exposure in a rock face, providing a three-dimensional view of the coal and gas outburst process. By employing a similar material simulation method, various indicators of the coal and gas outburst process can be measured, enabling a visualized quantitative simulation experiment. This provides an experimental basis for studying the outburst mechanism and process of coal and gas in rock face exposure and proposing targeted anti-outburst measures. (Throughout the entire process, only the coal seam where the auger robot, drill bit, and airbag are located is invisible. Under the illumination of the light source, a camera on the other side can accurately capture the position and changes of the auger robot, drill bit, and airbag, while the set displacement measuring points can accurately reflect the changes in the rock strata.)

[0044] The preferred embodiments of the present invention have been described in detail above. While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A method for simulating coal and gas outbursts in a tunnel under visual conditions, the method being implemented using a visual simulation experimental device for coal and gas outbursts in a tunnel under visual conditions, the experimental device comprising a frame structure, a tunneling device, a monitoring device, experimental materials, and a controller, wherein, The frame structure includes an experimental platform base, upright beams, crossbeams, hydraulic loading heads, protective beams, observation panels, ventilation devices, and inflation devices. The upright beams are located on the left and right sides, with their bottom ends fixed to the experimental platform base and their top ends fixedly connected via crossbeams. The middle or lower parts of the front and rear sides of the upright beams are respectively fixedly connected via protective beams. The upright beams on the left and right sides, together with the protective beams on the front and rear sides, form an accommodating space for accommodating and positioning a square observation window structure with open top and bottom. This square observation window structure is integrally formed from four transparent observation panels on the front, back, left, and right sides, with its bottom connected to the experimental platform base and its top covered by the square, plate-like crossbeams. Several hydraulic loading heads are installed at the bottom of the crossbeams to apply pressure to the experimental material to simulate geological stress. Exhaust fans are also installed on the left and right sides of the bottom of the crossbeams near the upright beams. An air extraction hole is provided on the upper part of the experimental platform base. Both the exhaust fans and the air extraction hole are connected to the ventilation device via exhaust pipes. The inflation device is connected to the interior of the accommodating space via pipes. Both the ventilation device and the inflation device are located outside the accommodating space. The experimental material is placed inside the square observation window structure. The experimental materials include rock strata simulation materials and coal seam simulation materials. The coal seam simulation materials are encased in airbags to form a closed strip-shaped coal seam. The gas pressure in the airbags is controlled by an external inflation device. The gas pressure in the airbags is used to simulate the gas pressure of the prototype coal seam. The experimental method is characterized by simulating a coal and gas outburst process by destroying an airbag with a tunneling device.

2. The method for simulating coal and gas outbursts in a visually controlled coal seam as described in claim 1, characterized in that, The tunneling device includes a tunneling drill bit and a gangue transport device. The tunneling drill bit is mounted on a small spiral drilling robot, which drives the tunneling drill bit to drill. The small spiral drilling robot is connected to a controller via a control signal line, and the controller controls its tunneling.

3. The method for simulating coal and gas outbursts in a visually-guided coal seam as described in claim 2, characterized in that, The gangue transport device includes a conveyor belt, conveyor belt pulleys, and tension springs. The conveyor belt is wound around the small spiral drilling robot, and the small spiral drilling robot provides the conveying power for the conveyor belt. At least two conveyor belt pulleys are provided, and the tension spring is located between the two conveyor belt pulleys. The connection point between the tension spring and the conveyor belt forms a triangular relationship with the two conveyor belt pulleys on both sides.

4. The method for simulating coal and gas outbursts in a visually controlled coal seam as described in claim 1, characterized in that, The monitoring device includes displacement measuring points, stress sensors, air pressure sensors, displacement measuring devices, and high-speed cameras. The displacement measuring points are evenly distributed on the front and back surfaces of the experimental material. The stress sensors are arranged in the roof, floor, and coal seam of the simulated coal seam. The air pressure sensors are set at the outlet of the air filling device. The high-speed cameras are set in the front and back sides of the frame structure for recording through the observation plate.

5. The method for simulating coal and gas outbursts in a visually controlled coal seam as described in claim 1, characterized in that, Rock strata simulation materials are made by mixing sand, gypsum, and calcium carbonate in a certain proportion; coal seam simulation materials are made by mixing sand, gypsum, calcium carbonate, and dyeing ink in a certain proportion.

6. The method for simulating coal and gas outbursts in a visually accessible coal seam as described in claim 5, characterized in that, The rock strata simulation materials and coal seam simulation materials are set according to the method of inclined coal seam laying.

7. A method for simulating coal and gas outbursts in a visually controlled coal seam as described in claim 5 or 6, characterized in that, The rock strata simulation material also incorporates optical fiber material, making it a light-transmitting material; furthermore, a light source is provided on the side of the frame structure opposite the high-speed camera.

8. The method for simulating coal and gas outbursts in a visually controlled coal seam as described in claim 1, characterized in that, The controller includes a display screen, gas pressure signal, tunneling control signal line, stress sensor signal line, high-speed camera control line, and displacement signal line. The controller's function is to control the pressure and displacement of the hydraulic loading head on the frame structure, control the tunneling of the tunneling device, control the ventilation device, control the gas pressure in the airbag, and receive stress displacement, gas pressure changes, and image monitoring data.

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