Fire preventing and extinguishing method for large goaf of coal-pillar-free island working face

Abstract

The invention discloses a fire preventing and extinguishing method for a large goaf of a coal-pillar-free island working face, and belongs to the field of working face fire preventing and extinguishing. A fire preventing and extinguishing method for a large goaf of a coal-pillar-free island working face comprises the steps that before working face stoping, the CO concentration of the goaf is detected in the modes of real-time online monitoring, regular manual detection and gas sample chromatographic analysis, and early warning is conducted on potential fire hazards; according to the concentration of CO in the air, a pressure-equalizing air control technology, a goaf guniting and leaking stoppage technology, a goaf grouting and nitrogen injection technology, a stopping agent spraying fire prevention and extinguishing technology or a combination of multiple technologies are adopted for prevention and control. Corresponding measures are taken according to the CO concentration of the goaf, on the premise that the mining safety of the working face is guaranteed, excessive prevention and control are avoided, waste of resources is reduced, the economical efficiency of coal mine enterprises is guaranteed, and the safety and the economical efficiency in the working face stoping process are both considered.

Description

Technical Field

[0001] The invention belongs to the field of fire prevention and extinguishing of working faces, and in particular relates to a fire prevention and extinguishing method for a large goaf area of ​​a coal pillar-free isolated island working face. Background Art

[0002] When conducting tunneling and coal mining operations underground in coal mines, according to Article 135 of the Coal Mine Safety Regulations, the concentration of carbon monoxide in the air underground shall not exceed 0.0024%. Many mines are coal and gas outburst and spontaneous combustion mines, with multiple coal seams mined together, and gas and fire compound disasters are serious. The scope of fire prevention and control in goaf areas is three times that of traditional mining work surfaces. The scope of spontaneous combustion prevention and control in goaf areas is large, the difficulty of governance is high, and there are many risk points of spontaneous combustion in goaf areas, which are difficult to identify.

[0003] Spontaneous combustion of coal in coal mines is one of the five major disasters in coal mines. Spontaneous combustion of coal has a long or short process of occurrence and development, and it is not easy to detect early because of the poor thermal conductivity of coal and rock. Most spontaneous combustion sources of coal are hidden, often occurring in goafs that are difficult for people to enter or in coal pillars that cannot be entered, making it difficult to extinguish them in time. Once a fire is formed, it comes with great force, even forcing the working face to stop mining and close, tens of millions or even hundreds of millions of yuan of mechanical equipment sealed in the fire area are damaged, and the amount of coal that has been developed and prepared is frozen, which directly affects the normal production and continuation of the mine. At the same time, the underground of the coal mine is a semi-enclosed space. During the occurrence and development of the fire, a large amount of toxic and harmful gases such as CO, CO2, SO2 and toxic smoke are produced, which seriously threatens the lives of miners. The water vapor and water gas produced during the fire extinguishing can only move in one direction. The working space and maneuvering room of the rescuers are small, which poses a great threat to the rescuers.

[0004] The coal pillar-free isolated island working face is more likely to cause spontaneous combustion of coal residue in the goaf due to the easy air leakage in the roadway, especially in the large goaf of the coal pillar-free isolated island working face, where the amount of coal residue is greater and the roadway air leakage is more serious. Therefore, it is urgent to provide a fire prevention and extinguishing method and technology for the large goaf of the coal pillar-free isolated island working face, reduce the risk of oxidation and spontaneous combustion of coal residue in the large goaf of the coal pillar-free isolated island working face, and ensure the safe and efficient recovery of the isolated island working face. Summary of the invention

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a fire prevention and extinguishing method for large goaf areas in coal pillar-free isolated island working faces, which solves the problems in the prior art.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A fire prevention and extinguishing method for a large goaf area in a coal pillar-free isolated island working face comprises the following steps:

[0008] S1, before the working face is mined, the CO concentration in the goaf is tested by real-time online monitoring, regular manual testing and gas sample chromatographic analysis to provide early warning of potential fire hazards;

[0009] S2, according to the concentration of CO in the air, adopt the following technologies: equalizing pressure and controlling wind technology, goaf spraying plugging technology, goaf grouting and nitrogen injection technology, spraying inhibitor fire prevention and extinguishing technology or a combination of multiple technologies for prevention and control.

[0010] Furthermore, the real-time online monitoring step is: installing CO sensors and temperature sensors on the air intake and return lanes and extraction pipelines in the goaf of the working face to achieve real-time online monitoring;

[0011] The regular manual inspection step is: setting fire observation holes for goafs every 100 to 200 meters in the machine tunnel and ventilation tunnel, and conducting regular manual inspections;

[0012] The gas sample chromatographic analysis steps are: laying a bundle pipe in the oxidation zone of the goaf, and extracting gas samples for chromatographic analysis.

[0013] Furthermore, when the CO concentration in the goaf is less than 14.4ppm, the equalizing pressure wind control technology is adopted; when the CO concentration is between 14.4ppm and 16.8ppm, the goaf spraying plugging technology is adopted; when the CO concentration is between 16.8ppm and 19.2ppm, the goaf grouting and nitrogen injection technology is adopted; when the CO concentration is between 19.2ppm and 21.6ppm, the spraying inhibitor fire prevention and extinguishing technology is adopted; when the CO concentration is greater than 21.6ppm, the above-mentioned multiple technologies are adopted for combined prevention and control.

[0014] Furthermore, the pressure-equalizing wind control technology includes: increasing the resistance of the air leakage channel by adjusting the angle of the fan blades in the air shaft and forcibly lowering the top, and reducing the resistance by expanding and repairing the return air channel.

[0015] Furthermore, the adjusting of the wind shaft fan blade angles refers to: adjusting the fan blade angles of two adjacent wind shafts according to the CO concentration in the goaf to reduce the wind pressure difference on both sides of the working face;

[0016] The forced roof release to increase the resistance of the air leakage channel means: taking shallow hole blasting measures to force the roof release of the working face machine and the air channel roof. If the roof release is not solid, the stacking belt is used to seal it to increase the resistance of the air leakage channel between the inlet and return air corners of the goaf.

[0017] Furthermore, the goaf spraying plugging technology includes: filling and sealing between the permanent closed wall and the riot-proof closed wall of the machine tunnel with water glass and yellow mud to plug air leakage in the goaf, reduce the air leakage pressure difference between the closed wall of the machine tunnel and the retained tunnel side, and perform full-section mesh spraying grouting on the retained tunnel side of the machine tunnel.

[0018] Furthermore, the goaf grouting and nitrogen injection technology includes: grouting in the coal waste area and nitrogen injection in the remaining pipelines in the machine tunnel.

[0019] Furthermore, the grouting of the coal-residual area refers to: during the mining period of the working face, a 4-inch fireproof pipeline is laid in the machine lane of the working face; during the initial mining period, the goaf opening and fault coal-residual area and the high-value CO area of ​​the original goaf are grouted by using the lane-retaining intubation pipe;

[0020] The nitrogen injection in the remaining pipelines in the machine lane means that during the period when the working face passes through the fault, the advancement speed of the working face slows down, and nitrogen is injected into the goaf using the pre-buried pipelines in the machine lane.

[0021] Furthermore, the fire prevention and extinguishing technology of spraying an inhibitor includes: spraying an inhibitor on the remaining coal after the working face is mined;

[0022] The inhibitor is a JD-MZH-1 type inhibitor, and the inhibitor and water are mixed at a concentration of not less than 10%, and the inhibitory rate is 45%-60%.

[0023] A fire prevention and extinguishing system for large goaf areas in coal pillar-free isolated island working faces, comprising:

[0024] Air detection module: Before the working face is mined, the CO concentration in the goaf is detected by real-time online monitoring, regular manual testing, and gas sample chromatographic analysis to provide early warning of potential fire hazards;

[0025] Fire extinguishing and prevention module: According to the concentration of CO in the air, the following technologies are used: pressure-equalizing wind control technology, goaf spraying plugging technology, goaf grouting and nitrogen injection technology, spraying inhibitor fire extinguishing technology or a combination of multiple technologies for prevention and control.

[0026] Beneficial effects of the present invention:

[0027] 1. Early warning and rapid response to fire hazards: Real-time online monitoring, regular manual testing, and gas sample chromatography analysis are used to detect gas in goafs for many years, which can provide early warning for potential fire hazards and take corresponding measures based on the CO content in the goaf, thereby achieving early warning and rapid response to fire hazards.

[0028] 2. Take into account both safety and economy. By detecting the gas in the goaf, potential fire hazards can be warned and corresponding measures can be taken according to the CO content in the goaf. Multiple technologies are used for joint prevention and control. Under the premise of ensuring the safety of the working face mining, excessive prevention and control is avoided, the waste of resources is reduced, and the economy of the coal mining enterprise is guaranteed. The safety and economy of the working face mining process are taken into account. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 It is a flow chart of the fire prevention and extinguishing method of the present invention;

[0031] Figure 2 It is a flow chart of fire prevention prediction and forecasting of the present invention;

[0032] Figure 3 It is a flow chart of fire prevention and extinguishing measures in the working face mining process of the present invention;

[0033] Figure 4 This is a table of fire prevention measures corresponding to CO concentration of the present invention. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] like Figure 1 As shown, a fire prevention and extinguishing method for a large goaf area of ​​a coal pillar-free isolated island working face comprises the following steps:

[0036] S1, before the working face is mined, the CO concentration in the goaf is detected using fire prevention prediction technology to provide early warning of potential fire hazards;

[0037] like Figure 2 As shown, the fire prevention prediction and forecasting technology includes: real-time online monitoring, regular manual detection and gas sample chromatographic analysis;

[0038] The steps of real-time online monitoring are as follows: install CO sensors and temperature sensors on the extraction pipelines of the working face intake, return air lanes, and goaf areas for real-time online monitoring;

[0039] The steps for regular manual inspection are as follows: set up fire observation holes for goaf every 100 to 200 meters in the machine tunnel and ventilation tunnel, and conduct regular manual inspection;

[0040] The steps of chromatographic analysis of gas samples are as follows: laying bundle pipes in the oxidation zone of the goaf and extracting gas samples for chromatographic analysis.

[0041] S2, according to the concentration of CO in the air, adopt the following technologies: pressure-equalizing wind control technology, goaf spraying plugging technology, goaf grouting and nitrogen injection technology, spraying inhibitor fire prevention and extinguishing technology or a combination of multiple technologies for prevention and control;

[0042] Specifically, if Figure 3 As shown in the figure, when the CO concentration in the goaf is less than 14.4ppm, the pressure-equalizing air control technology is used; when the CO concentration is between 14.4ppm and 16.8ppm, the goaf spraying plugging technology is used; when the CO concentration is between 16.8ppm and 19.2ppm, the goaf grouting and nitrogen injection technology is used; when the CO concentration is between 19.2ppm and 21.6ppm, the spraying inhibitor fire prevention and extinguishing technology is used; when the CO concentration is greater than 21.6ppm, the above-mentioned multiple technologies are used for joint prevention and control. Thus, early warning and rapid response to fire hazards are achieved, and the effect of fire prevention measures can be evaluated and fed back according to the gas detection in the goaf, which effectively prevents and controls the risk of spontaneous combustion caused by the slow oxidation of the coal left in the goaf during the mining process of the working face, and ensures the safe and efficient mining of the working face.

[0043] like Figure 4 As shown, the pressure-equalizing wind control technology includes: increasing the resistance of the air leakage channel by adjusting the angle of the fan blades in the air shaft, forcibly lowering the top, and expanding and repairing the return air channel to reduce the resistance;

[0044] Among them, adjusting the angle of the fan blades of the wind shaft means: adjusting the angles of the fan blades of two adjacent wind shafts according to the CO concentration in the goaf to reduce the wind pressure difference on both sides of the working face;

[0045] Forced roof caving to increase resistance to air leakage channels means: taking shallow hole blasting measures to force roof caving on the working face machine and airway roof. If the caving is not solid, the stacking belt is used to block the air leakage channel between the inlet and return air corners of the goaf to increase resistance;

[0046] Expanding and repairing the return air channel to reduce resistance means: expanding and repairing the return air channel, increasing the ventilation cross-section, and reducing ventilation resistance.

[0047] The goaf spraying plugging technology includes: filling and sealing between the permanent closed wall and the riot-proof closed wall of the machine tunnel with water glass and yellow mud to plug the air leakage in the goaf, reduce the air leakage pressure difference between the closed wall of the machine tunnel and the retained tunnel side, and perform full-section mesh spraying grouting on the retained tunnel side of the machine tunnel.

[0048] The goaf grouting and nitrogen injection technology includes: grouting in the coal waste area and nitrogen injection in the pipelines left behind in the machine lane;

[0049] Grouting of the coal-residue area means: during the mining period of the working face, a 4-inch fireproof pipeline is laid in the machine lane of the working face. During the initial mining period, the goaf opening and fault coal-residue area and the high-value CO area of ​​the original goaf are grouted by using the reserved lane intubation pipe;

[0050] Nitrogen injection in the remaining pipelines in the machine lane means that during the period when the working face passes through the fault, the advancement speed of the working face slows down, and nitrogen is injected into the goaf using the pre-buried pipelines in the machine lane.

[0051] The fire prevention and extinguishing technology of spraying inhibitor includes: spraying inhibitor on the remaining coal after the working face is mined;

[0052] The inhibitor can be JD-MZH-1 type inhibitor, 25kg per bag, the inhibitor and water are mixed at a concentration of not less than 10%, and the inhibitory rate is 45%-60%.

[0053] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0054] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A fire prevention and extinguishing method for large goaf areas in coal pillar-free isolated island working faces, characterized in that: The following steps are involved: S1, before the working face is mined, the CO concentration in the goaf is tested by real-time online monitoring, regular manual testing and gas sample chromatographic analysis to provide early warning of potential fire hazards; S2, according to the concentration of CO in the air, adopt the following technologies: equalizing pressure and controlling wind technology, goaf spraying plugging technology, goaf grouting and nitrogen injection technology, spraying inhibitor fire prevention and extinguishing technology or a combination of multiple technologies for prevention and control.

2. A fire prevention and extinguishing method for large goaf in isolated island working face without coal pillars according to claim 1, characterized in that: The real-time online monitoring steps are: installing CO sensors and temperature sensors on the extraction pipelines of the working face intake and return air lanes and goaf areas to achieve real-time online monitoring; The regular manual inspection step is: setting fire observation holes for goafs every 100 to 200 meters in the machine tunnel and ventilation tunnel, and conducting regular manual inspections; The gas sample chromatographic analysis steps are: laying a bundle pipe in the oxidation zone of the goaf, and extracting gas samples for chromatographic analysis.

3. A fire prevention and extinguishing method for large goaf in isolated island working face without coal pillars according to claim 1, characterized in that: When the CO concentration in the goaf is less than 14.4ppm, the equalized pressure wind control technology is adopted; when the CO concentration is between 14.4ppm and 16.8ppm, the goaf spraying plugging technology is adopted; when the CO concentration is between 16.8ppm and 19.2ppm, the goaf grouting and nitrogen injection technology is adopted; when the CO concentration is between 19.2ppm and 21.6ppm, the spraying inhibitor fire prevention and extinguishing technology is adopted; when the CO concentration is greater than 21.6ppm, the above-mentioned multiple technologies are adopted for combined prevention and control.

4. A fire prevention and extinguishing method for large goaf in isolated island working face without coal pillars according to claim 1, characterized in that: The pressure-equalizing wind control technology includes: increasing the resistance of the air leakage channel by adjusting the angle of the fan blades in the air shaft, forcibly lowering the top, and reducing the resistance by expanding and repairing the return air channel.

5. A fire prevention and extinguishing method for large goaf in isolated island working face without coal pillars according to claim 4, characterized in that: The adjusting of the blade angle of the wind shaft fan refers to: adjusting the blade angles of the two adjacent wind shaft fans according to the CO concentration in the goaf to reduce the wind pressure difference on both sides of the working face; The forced roof release to increase the resistance of the air leakage channel means: taking shallow hole blasting measures to force the roof release of the working face machine and the air channel roof. If the roof release is not solid, the stacking belt is used to seal it to increase the resistance of the air leakage channel between the inlet and return air corners of the goaf.

6. A fire prevention and extinguishing method for large goaf in isolated island working face without coal pillars according to claim 1, characterized in that: The goaf spraying plugging technology includes: filling and sealing between the permanent closed wall and the riot-proof closed wall of the machine tunnel with water glass and yellow mud to plug the air leakage in the goaf, reduce the air leakage pressure difference between the closed wall of the machine tunnel and the retained tunnel side, and perform full-section mesh spraying grouting on the retained tunnel side of the machine tunnel.

7. A fire prevention and extinguishing method for large goaf in isolated island working face without coal pillars according to claim 1, characterized in that: The goaf grouting and nitrogen injection technology includes: grouting in the coal waste area and nitrogen injection in the remaining pipelines in the machine tunnel.

8. A fire prevention and extinguishing method for large goaf in isolated island working face without coal pillars according to claim 7, characterized in that: Grouting of the coal-residual area refers to: during the mining period of the working face, a 4-inch fireproof pipeline is laid in the machine lane of the working face; during the initial mining period, the goaf opening and fault coal-residual area and the high-value CO area of ​​the original goaf are grouted by using the reserved lane intubation pipe; The nitrogen injection in the remaining pipelines in the machine lane means that during the period when the working face passes through the fault, the advancement speed of the working face slows down, and nitrogen is injected into the goaf using the pre-buried pipelines in the machine lane.

9. A fire prevention and extinguishing method for large goaf in isolated island working face without coal pillars according to claim 1, characterized in that: The fire prevention and extinguishing technology of spraying inhibitor includes: spraying inhibitor on the remaining coal after the working face is mined; The inhibitor is a JD-MZH-1 type inhibitor, and the inhibitor and water are mixed at a concentration of not less than 10%, and the inhibitory rate is 45%-60%.

10. A fire prevention and extinguishing system for large goaf areas in isolated island working faces without coal pillars, characterized in that: include: Air detection module: Before the working face is mined, the CO concentration in the goaf is detected by real-time online monitoring, regular manual testing, and gas sample chromatographic analysis to provide early warning of potential fire hazards; Fire extinguishing and prevention module: According to the concentration of CO in the air, the following technologies are used: pressure-equalizing wind control technology, goaf spraying plugging technology, goaf grouting and nitrogen injection technology, spraying inhibitor fire extinguishing technology or a combination of multiple technologies for prevention and control.

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