A coal spontaneous combustion danger area monitoring and preventing system based on communication lane sealing

Abstract

The application provides a coal spontaneous combustion danger area monitoring and preventing system based on a communication lane sealing, which comprises three subsystems: a precise gas collection system, which uses a gas suction pump to stably extract the gas in a goaf through the communication lane sealing, so as to ensure the stability and accuracy of the gas collection; a coal spontaneous combustion danger area precise determination system, which is used for arranging temperature monitoring and gas determination devices to fully cover the large goaf through the communication lane sealing, so as to finely grade and early warn the coal spontaneous combustion danger area in the large goaf, and combine the monitoring and the prevention of the coal spontaneous combustion danger area in the goaf; and a fire preventing and extinguishing effect real-time evaluation system, which is used for monitoring the change of the gas and the temperature in the large goaf in real time at the communication lane sealing after the fire preventing and extinguishing measures are implemented, so as to reflect the fire extinguishing effect in a whole process in real time.

Description

Technical Field

[0001] The invention relates to the field of monitoring technology for coal spontaneous combustion hazard areas in large goaf areas, and more particularly to a monitoring and prevention system for coal spontaneous combustion hazard areas based on the closed connecting roadway. Background Technology

[0002] In the overall layout of mining operations, western mines have auxiliary transport roadways, which are connected to the working face intake airway via connecting roadways. This facilitates the transportation of equipment, materials, and personnel. The connection roadway also provides a stable environment for determining the risk zone of spontaneous combustion of coal in the goaf.

[0003] Currently, Chinese invention patent CN114460260A discloses a method for monitoring the spontaneous combustion hazard zone of residual coal in the goaf of a fully mechanized longwall mining face. This method achieves overall monitoring of the temperature, gas composition, and gas pressure variations within the goaf from the upper and lower corners to the middle area along the dip direction. However, gas extraction at the upper and lower corners is unstable, resulting in inaccurate data. Invention patent CN115013032A discloses a dynamic observation method for the "three zones" of the goaf, mainly by extracting gas from the goaf and analyzing it with a chromatograph. However, the obtained gas data is inaccurate and does not consider monitoring the internal temperature of the goaf. Chinese invention patent CN110700875A discloses a system and method for measuring the three zones of spontaneous combustion in goaf areas. It mainly divides the three zones of goaf areas through gas monitoring devices and temperature monitoring devices. However, the gas data it extracts is inaccurate and it is difficult to achieve early warning and prevention of coal spontaneous combustion hazard areas in goaf areas. Chinese patent document CN105863714A describes a monitoring system for the three zones of spontaneous combustion in goaf areas. It includes horizontal and vertical monitoring equipment for monitoring the three zones of spontaneous combustion in the horizontal direction and vertical direction of the goaf area. However, when applied to large goaf areas, the monitoring results are not accurate enough due to the limited number of sampling points.

[0004] In summary, existing methods for determining the risk zone of spontaneous combustion of coal in goaf areas have provided guidance for fire prevention and extinguishing efforts to some extent. However, these methods are all implemented at the corners of the intake and return airways. Due to the complex construction conditions and severe air leakage at these corners, and the fact that the location of the work arrangement constantly shifts with the progress of mining, the collected gas samples are inaccurate, resulting in imprecise monitoring data. In contrast, the sealed connecting roadway provides a stable and fixed working environment for on-site construction, effectively improving the accuracy of data collection. Therefore, designing a coal spontaneous combustion risk zone monitoring and prevention system based on the sealed connecting roadway is particularly important. Summary of the Invention

[0005] This invention provides a monitoring and prevention system for coal spontaneous combustion hazard areas based on a sealed connecting roadway. It considers deploying the monitoring system from the sealed part of the connecting roadway to the goaf, thus avoiding the technical problem of inaccurate monitoring data caused by inaccurate air extraction at the corner of the intake and return air.

[0006] The objective of this invention can be achieved through the following technical solution: a monitoring and prevention system for coal spontaneous combustion hazard areas based on the closed connection roadway, including a precise gas acquisition system, a precise coal spontaneous combustion hazard area determination system, and a real-time evaluation system for fire prevention and extinguishing effects;

[0007] The precision gas acquisition system is equipped with an extraction device, which includes a multi-core bundle tube, an extraction pump, and a gas storage belt. The precision gas acquisition system is used to extract and detect gas from the goaf area.

[0008] The coal spontaneous combustion hazard zone accurate determination system is equipped with a gas chromatograph, a temperature monitoring device and the gas extraction device. The temperature monitoring device includes a temperature sensor, an optical fiber and a reading instrument. Based on the detection results of the extracted gas and temperature in the goaf, the range of the coal spontaneous combustion hazard zone in the goaf is further refined.

[0009] The real-time fire prevention and extinguishing effect evaluation system is equipped with a grouting pipe, a nitrogen injection pipe, a gas chromatograph, an air extraction device, and a temperature monitoring device. It monitors and tracks the internal conditions of the goaf in real time and evaluates the fire extinguishing effect.

[0010] Once the connecting roadway enters the goaf area, it becomes sealed, thus forming a sealed connecting roadway.

[0011] Several sampling points are arranged sequentially from the sealed section of the connecting roadway toward the goaf to form a sampling column, and the distance between any two adjacent sampling points in the column is equal.

[0012] Furthermore, the gas extraction device, gas chromatograph, temperature monitoring device, grouting pipe, and nitrogen injection pipe are all arranged with multiple sampling points in a vertical direction from the sealed connecting roadway to the goaf, forming a sampling column, and the distance between any two adjacent sampling points is equal.

[0013] Furthermore, the number of branch tubes within the multi-core bundle tube is determined based on the number of sampling points in the sampling column, and the multi-core bundle tube has several perforations at each sampling point position.

[0014] Furthermore, the gas pump extracts gas from the goaf sampling point to the sealed area of ​​the connecting roadway through the multi-core bundle tube, and transfers it to the gas chromatograph using the gas storage belt for determining the concentrations of O2, CO, C2H4, and C2H2 gases.

[0015] Furthermore, the temperature sensor reads the temperature of the goaf sampling point in the sealed area of ​​the connecting roadway through the optical fiber, and each optical fiber is placed in the gap between adjacent branch bundles.

[0016] Furthermore, the grouting pipe and nitrogen injection pipe are used to prevent spontaneous combustion of coal in the goaf. Based on the results of the precise determination system for the coal spontaneous combustion hazard area, fire prevention and extinguishing materials are injected into the designated coal spontaneous combustion area in the goaf through the grouting pipe and nitrogen injection pipe.

[0017] Furthermore, the grouting pipe is positioned at a height of 0.6m above the bottom plate; the nitrogen injection pipe is positioned at a high-temperature location 1.6m above the bottom plate.

[0018] Furthermore, the air extraction device, gas chromatograph, and temperature monitoring device in the real-time fire prevention and extinguishing effect evaluation system monitor and track the situation inside the goaf in real time, and then make a reasonable evaluation of the effect of the implemented fire prevention and extinguishing measures based on the measured gas concentrations and temperatures.

[0019] Furthermore, the specific steps for the on-site deployment method of the monitoring and prevention system for coal spontaneous combustion hazard areas based on the closed connecting roadway are as follows:

[0020] Monitoring devices and tubing were installed in the enclosed areas of the connecting alley.

[0021] Step 1: Using the centerline of the coal pillar between adjacent connecting roadways as the baseline, as the working face is mined, when the left side surface of the goaf moves away from the baseline, grouting pipes and nitrogen injection pipes are arranged at equal intervals along the surface of the goaf from the sealed part of the connecting roadway.

[0022] Step 2: As the working face is mined, when the left side surface of the goaf reaches the middle of the connecting roadway, sampling points are arranged at equal intervals along the surface of the goaf from the sealed part of the connecting roadway to form a sampling line;

[0023] Step 3: Install extraction pipes and temperature sensors at each sampling point, and obtain monitoring data in the sealed area of ​​the connecting tunnel using a gas chromatograph and temperature monitoring device.

[0024] The beneficial effects of this invention are:

[0025] (1) The present invention extracts gas from the sealed part of the connecting roadway to the gas sampling point in the goaf, providing a stable and fixed gas extraction environment, avoiding the unstable gas extraction phenomenon in the corner of the intake and return air under the traditional situation, and effectively improving the accuracy of data monitoring.

[0026] (2) This invention uses a gas chromatograph to analyze the concentration of gases such as O2, CO, C2H4, and C2H2 at each gas sampling point in the sealed area of ​​the connecting roadway, and monitors the temperature at each temperature sampling point, thereby achieving precise monitoring and graded early warning of the spontaneous combustion hazard area in a large-scale goaf.

[0027] (3) Based on the results of the coal spontaneous combustion hazard zone accurate determination system, the present invention takes timely preventive measures for coal spontaneous combustion hazard zones in the closed area of ​​the connecting roadway through grouting pipes and nitrogen injection pipes. At the same time, it can also rely on the coal spontaneous combustion hazard zone accurate determination system to continuously track the fire prevention and extinguishing effect. Attached Figure Description

[0028] The invention will now be further described with reference to the accompanying drawings.

[0029] Figure 1 This is a schematic diagram of the on-site layout of the system for arranging the system from the sealed connecting roadway to the goaf area according to the present invention;

[0030] Figure 2 A cross-sectional view showing the arrangement of grouting pipes and nitrogen injection pipes in the goaf area according to the present invention;

[0031] Figure 3 This is a side view of the multi-core bundle tube of the present invention.

[0032] In the diagram, the labels represent: 1. Monitoring and sampling column, 2. Prevention arrangement column, 3. Multi-core bundled tube, 4. Branch bundled tube within the multi-core bundled tube, 5. Optical fiber, 6. Grouting tube, and 7. Nitrogen injection tube. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] To facilitate understanding of this invention, through Figure 1 The structural diagram is used to briefly illustrate the construction of a mine working face with connecting roadways. For example... Figure 1 As shown, coal mining is always carried out using a return mining method. Before mining, two roadways are typically dug deep into the coal seam: an intake airway and a return airway. Then, these two roadways are connected along the surface of the deepest coal seam to form the working face. However, coal mining proceeds gradually from the rightmost side of the working face to the left. After mining, the working face eventually forms a goaf due to roof collapse. Connecting roadways are formed by digging several roadways at equal intervals between the intake airway and the auxiliary transport roadways through the coal pillars.

[0035] The coal spontaneous combustion hazard monitoring and prevention system provided in this embodiment of the invention includes an extraction device, a temperature measuring device, and an early warning and prevention device. By extracting and detecting gas from the goaf, the scope of the coal spontaneous combustion hazard area in the goaf can be refined. The temperature measuring device obtains the temperature changes inside the goaf. The early warning and prevention device injects fire-fighting materials into the goaf to prevent coal spontaneous combustion from occurring in the goaf.

[0036] Based on the on-site conditions of the working face, a method for the on-site deployment of a monitoring and prevention system for coal spontaneous combustion hazard areas in the closed connecting roadway was adopted:

[0037] Monitoring devices and tubing were installed in the enclosed areas of the connecting alley.

[0038] (1) Take the centerline of the coal pillar between adjacent connecting roadways as the baseline. As the working face is mined, when the left side surface of the goaf is away from the baseline, grouting pipes and nitrogen injection pipes are arranged at equal intervals along the surface of the goaf from the sealed part of the connecting roadway.

[0039] (2) As the working face is mined, when the left side surface of the goaf reaches the middle of the connecting roadway, sampling points are arranged at equal intervals along the surface of the goaf from the sealed part of the connecting roadway to form a sampling line.

[0040] (3) Install extraction pipes and temperature sensors at each sampling point, and obtain monitoring data at the sealed area of ​​the connecting roadway using a gas chromatograph and temperature monitoring device. Specific implementation examples:

[0042] like Figures 1 to 3 As shown, the specific steps of this invention are as follows: A monitoring and prevention system for coal spontaneous combustion hazard areas based on a sealed connecting roadway, the specific steps of an implementation example are as follows:

[0043] A. Selection of construction materials

[0044] The equipment for determining the risk zone of spontaneous combustion of coal in goaf areas according to the present invention includes: a multi-core bundled tube 3, a vacuum pump, a temperature sensor, an optical fiber 5, a gas chromatograph, a grouting pipe 6, a nitrogen injection pipe 7, and a gas storage belt.

[0045] The number of branch tubes 4 in the multi-core tube is determined according to the number of sampling points in the sampling column, and the multi-core tube has multiple perforations at each sampling point.

[0046] B. Determine the construction location

[0047] First, the width of the connecting roadway is determined on-site, and the midpoint of the coal pillar between adjacent connecting roadways is extended into the goaf as the baseline. Monitoring and prevention devices are then installed at the sealed sections of the connecting roadways.

[0048] In the Chahasu Coal Mine, some coal seams contain one to two layers of interbedded rock. These interbedded rock and the coal seam floor are prone to mudification when exposed to water, causing bottom swelling. Therefore, bottom coal must be reserved during tunneling. The thickness of the bottom coal should not exceed 0.5m. Accordingly, the sampling point should be arranged at a height higher than 0.5m, and 0.6m is a suitable height in this case.

[0049] C. Sampling point layout

[0050] Sampling columns were arranged in the goaf according to the on-site layout method of the monitoring and prevention system for coal spontaneous combustion hazard areas based on the closed connecting roadway, with the distance between adjacent sampling points in each sampling column being equal.

[0051] Gas and temperature samples were taken at the same sampling point, and each sampling point was arranged along the leftmost surface of the goaf from the middle of the sealed connecting roadway.

[0052] D. Install the air extraction device

[0053] First, determine the number of independent branch tubes 4 in the multi-core bundle tube and the distance between each sampling point. Pass the multi-core bundle tube through each sampling point sequentially, and at each sampling point, remove a single branch tube 4 of the multi-core bundle tube by drilling. After the connecting roadway is sealed, install a vacuum pump, connect the multi-core bundle tube to the vacuum pump, extract gas from the goaf and load it into a gas storage belt, and then inject the extracted gas into a gas chromatograph for analysis and detection.

[0054] E. Install temperature monitoring devices

[0055] Preferably, the number of independent branch bundles 4 in the multi-core bundle is determined, and then the number of gaps between adjacent branch bundles is determined.

[0056] The optical fiber 5 is sequentially passed through the gap between adjacent branch bundles 4 to each sampling point. At each sampling point, the optical fiber 5 is removed through a drilled hole, and a temperature sensor is placed at each sampling point to monitor the temperature of the goaf in real time. The temperature sensor is connected to the optical fiber 5, passes through each individual branch bundle 4, and finally, at the sealed part of the connecting roadway, a data reader is placed and connected to the sensing optical fiber to obtain the temperature of the goaf.

[0057] F. Deploy early warning and prevention devices

[0058] Prioritize green as the color for the bundled tubes used for early warning and prevention. Based on the arrangement of sampling points using extraction and temperature monitoring devices, grouting pipes 6 and nitrogen injection pipes 7 are deployed into the goaf area. An opening is drilled at each point to transport gas or liquid into the goaf.

[0059] Specifically, the grouting pipe 6 is arranged at a height of 0.6m from the bottom plate; the nitrogen injection pipe 7 is arranged at a height of 1.6m from the bottom plate.

[0060] In summary, this invention provides a monitoring and prevention system for coal spontaneous combustion hazard areas based on a sealed connecting roadway. By deploying the coal spontaneous combustion hazard detection system from the sealed connecting roadway towards the goaf, it avoids the technical problem of inaccurate monitoring data caused by inaccurate air extraction at the intake and return air corners, effectively improving the accuracy of monitoring data and enabling precise reduction of the spontaneous combustion range in large goaf areas. Furthermore, by combining monitoring and prevention, it achieves continuous tracking of fire prevention and extinguishing effects.

[0061] The above description is merely an example and illustration of the structure of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the structure of the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A monitoring and prevention system for coal spontaneous combustion hazard areas based on sealed connecting roadways, characterized in that, This includes a precise gas acquisition system, a precise coal spontaneous combustion hazard zone determination system, and a real-time fire prevention and extinguishing effectiveness evaluation system; The precision gas acquisition system is equipped with an extraction device, which includes a multi-core bundle tube, an extraction pump, and a gas storage belt. The precision gas acquisition system is used to extract and detect gas from the goaf area. The coal spontaneous combustion hazard zone accurate determination system is equipped with a gas chromatograph, a temperature monitoring device and the gas extraction device. The temperature monitoring device includes a temperature sensor, an optical fiber and a reading instrument. Based on the detection results of the extracted gas and temperature in the goaf, the range of the coal spontaneous combustion hazard zone in the goaf is further refined. The real-time fire prevention and extinguishing effect evaluation system is equipped with a grouting pipe, a nitrogen injection pipe, a gas chromatograph, an air extraction device, and a temperature monitoring device. It monitors and tracks the internal conditions of the goaf in real time and reflects the fire extinguishing effect. Once the connecting roadway enters the goaf area, it becomes sealed, thus forming a sealed connecting roadway. Several sampling points are arranged sequentially from the sealed section of the connecting roadway toward the goaf area to form a sampling column, and the distance between any two adjacent sampling points in the several sampling points is equal; The specific steps for the on-site deployment of the monitoring and prevention system for coal spontaneous combustion hazard areas in enclosed connecting roadways are as follows: Monitoring devices and tubing were installed in the enclosed areas of the connecting alley. Step 1: Using the centerline of the coal pillar between adjacent connecting roadways as the baseline, as the working face is mined, when the left side surface of the goaf moves away from the baseline, grouting pipes and nitrogen injection pipes are arranged at equal intervals along the surface of the goaf from the sealed part of the connecting roadway. Step 2: As the working face is mined, when the left side surface of the goaf reaches the middle of the connecting roadway, sampling points are arranged at equal intervals along the surface of the goaf from the sealed part of the connecting roadway to form a sampling line; Step 3: Install extraction pipes and temperature sensors at each sampling point, and obtain monitoring data in the sealed area of ​​the connecting tunnel using a gas chromatograph and temperature monitoring device.

2. The monitoring and prevention system for coal spontaneous combustion hazard areas based on a sealed connecting roadway as described in claim 1, characterized in that, The extraction device, gas chromatograph, temperature monitoring device, grouting pipe, and nitrogen injection pipe are all arranged with multiple sampling points in a vertical direction from the sealed connecting roadway to the goaf, forming a sampling column, and the distance between any two adjacent sampling points is equal.

3. The monitoring and prevention system for coal spontaneous combustion hazard areas based on a sealed connecting roadway as described in claim 2, characterized in that, The number of branch tubes in the multi-core tube is determined according to the number of sampling points in the sampling column, and the multi-core tube has several perforations at each sampling point position.

4. The monitoring and prevention system for coal spontaneous combustion hazard areas based on a sealed connecting roadway as described in claim 3, characterized in that, The gas pump extracts gas from the sampling point in the goaf through the multi-core bundle tube to the sealed area of ​​the connecting roadway, and then transfers it to the gas chromatograph using the gas storage belt to determine the concentrations of O2, CO, C2H4, and C2H2 gases.

5. A monitoring and prevention system for coal spontaneous combustion hazard areas based on a sealed connecting roadway, as described in claim 4, is characterized in that... The temperature sensor reads the temperature of the goaf sampling point in the sealed area of ​​the connecting roadway through the optical fiber, and each optical fiber is placed in the gap between adjacent branch bundles.

6. A monitoring and prevention system for coal spontaneous combustion hazard areas based on a sealed connecting roadway, as described in claim 5, is characterized in that... The grouting pipe and nitrogen injection pipe are used to prevent spontaneous combustion of coal in the goaf. Based on the results of the coal spontaneous combustion hazard area determination system, fire prevention and extinguishing materials are injected into the designated coal spontaneous combustion area in the goaf through the grouting pipe and nitrogen injection pipe.

7. A monitoring and prevention system for coal spontaneous combustion hazard areas based on a sealed connecting roadway, as described in claim 6, is characterized in that... The grouting pipe is positioned at a height of 0.6m from the bottom plate; the nitrogen injection pipe is positioned at a high-temperature location 1.6m from the bottom plate.

8. A monitoring and prevention system for coal spontaneous combustion hazard areas based on a sealed connecting roadway, as described in claim 7, is characterized in that... The real-time fire prevention and extinguishing effect evaluation system includes an air extraction device, a gas chromatograph, and a temperature monitoring device to monitor and track the situation inside the goaf in real time, and then evaluates the effectiveness of the implemented fire prevention and extinguishing measures based on the detected gas concentrations and temperatures.

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