Island left coal pillar resource roadway system and fire prevention and extinguishing cooperative re-mining planning method

Abstract

The invention belongs to the technical field of remain coal resource re-mining roadway system planning and fire prevention and extinguishing control, and discloses an island remain coal pillar resource roadway system and a fire prevention and extinguishing cooperative re-mining planning method. According to the method, a mining roadway is arranged in a left coal pillar, and a small coal pillar is reserved; inorganic cured foam is sprayed to the surface of surrounding rock in the roadway tunneling period to form a blocking layer, a macromolecule foaming material is injected into cracks, and gaps of a top beam of a support are filled with a flame-retardant nylon net and fireproof cotton for blocking; in the stoping period, the measure that stopping agent spraying behind a support is combined with goaf nitrogen injection while mining is adopted, and an intelligent system based on the ANFIS-TOPSIS algorithm is constructed to conduct dynamic regulation and control on spraying and nitrogen injection; a double-isolation facility composed of a wind-shield wall and a wind-shield curtain is arranged at an air inlet and return corner. Physical plugging is adopted in the roadway tunneling period, gob dynamic inerting and working face spraying restraining are conducted in the stoping period, and a whole-process intelligent monitoring system is adopted, so that full-period prevention and control of the spontaneous combustion risk of the coal seam are achieved.

Description

Technical Field

[0001] This invention belongs to the field of planning and fire prevention and control technology for roadway systems in the re-mining of abandoned coal resources, and particularly relates to a planning method for roadway systems in isolated abandoned coal pillar resources and coordinated fire prevention and control for re-mining. Background Technology

[0002] Spontaneous combustion of coal seams is one of the major hazards in coal mines, especially in high-gas, isolated working faces. Residual coal in adjacent goaf areas forms a highly concealed spontaneous combustion bed. Mining disturbances inevitably disrupt the original sealed state, creating air leakage channels. The influx of oxygen easily triggers large-scale re-ignition of residual coal in the goaf, producing large amounts of toxic and harmful gases, seriously threatening personnel and production safety. Furthermore, the location of roadways, which are essential for personnel, equipment, and ventilation, and the fire prevention and extinguishing measures within them directly determine the difficulty of fire prevention and extinguishing work, and are also crucial to the success or failure of fire prevention and extinguishing in isolated working faces. Traditional fire prevention and extinguishing technologies include grouting, nitrogen injection, and spraying inhibitors, but these suffer from uneven coverage, poor inerting effects, and material corrosion of equipment, making them unsuitable for complex geological conditions.

[0003] Therefore, in the remining of isolated coal pillar resources, strengthening mine fire prevention and extinguishing work is the core link in building a solid underground safety line and protecting the lives and health of miners. It is necessary to carry out targeted and systematic fire prevention and extinguishing plan design to fundamentally curb the risk of spontaneous combustion and ensure safe mining of the working face.

[0004] Based on the above analysis, the problems and shortcomings of the existing technology are as follows: (1) When remining isolated coal pillars, the planning and design of the roadway system often only considers the convenience of tunneling and mining, resulting in the roadway layout and fire prevention and extinguishing measures being disconnected from each other, lacking systematic source control.

[0005] (2) Traditional grouting, nitrogen injection or spraying inhibitor technology adopts a fixed parameter and continuous operation mode. The fire prevention and extinguishing measures are simple and crude, lack linkage, and it is difficult to achieve precise inerting of the "oxidation zone" in the goaf.

[0006] (3) The existing monitoring system only has data acquisition and threshold alarm functions, and cannot deeply integrate and mine massive monitoring data. It lacks an adaptive intelligent decision-making system and is slow to respond to sudden fires.

[0007] (4) Existing windbreak walls or curtains at the corners of the air inlet and outlet usually only have a simple "windbreak" function and are simple in structure, resulting in weak control of corner and lateral air leakage and single function of sealing facilities.

[0008] (5) In order to improve the resource recovery rate, some working faces need to release coal from both sides. However, the existing technology does not fully understand the risk of lateral air leakage that may be caused by such processes, and lacks a targeted method for constructing "side isolation zone in goaf". This results in the goaf being directly connected to the adjacent working space after coal release, which greatly increases the risk of spontaneous combustion. Summary of the Invention

[0009] To overcome the problems existing in related technologies, the present invention discloses an embodiment of a method for planning the coordinated remining of isolated legacy coal pillar resource roadways with fire prevention and extinguishing, the technical solution of which is as follows: This invention is implemented as follows: a method for coordinating the planning of roadway systems for isolated coal pillar resources with fire prevention and extinguishing, comprising the following steps: S1. Based on the geological data of the mine, assess the conditions for remining the coal seam, arrange the mining roadway in the remaining coal pillar, and reserve a small coal pillar with a width of 2m to 3m. S2. During tunnel excavation, inorganic solidified foam material is sprayed onto the surface of the surrounding rock to form an inorganic solidified foam barrier layer and to seal the cracks in the surrounding rock. S3. During the roadway mining period, a combination of spraying inhibitors after the support frame and injecting nitrogen into the goaf is adopted as mining and prevention measures are implemented. An intelligent system for monitoring and proactive joint prevention of spontaneous combustion of coal in the goaf based on monitoring data is constructed to dynamically regulate the spraying and nitrogen injection measures. S4. Fireproof and sealed double isolation facilities consisting of windbreak walls and / or windbreak curtains shall be installed at the air inlet and return corners of the working face. S5. If coal is discharged from both sides of the working face, a step-like polymer solidified foam isolation wall is constructed behind the support to form a lateral isolation zone in the goaf.

[0010] In step S2, the sealing treatment of the surrounding rock fissures includes: For cracks in the roof and sidewalls of the roadway, inject polymer foam material to form a sealed layer; for the gaps between the roof support and the support beam and the roof, use flame-retardant nylon mesh and fireproof cotton to fill them.

[0011] Furthermore, the expansion ratio of the polymer foam material is 15 to 30 times, the reaction time is 30 to 90 seconds, and the compressive strength of the sealing layer after curing is not less than 0.8 MPa; The flame-retardant nylon mesh has a mesh size of 10mm×10mm to 20mm×20mm and an oxygen index ≥28%; the fireproof cotton is mining-grade aluminosilicate fiber cotton with a filling thickness of 30mm~100mm and a density of 80kg / m³. 3 ~120kg / m 3 .

[0012] In step S3, the intelligent system for monitoring and proactively preventing spontaneous combustion of coal in the goaf includes: The monitoring subsystem is used to collect and analyze the gas composition and concentration in the goaf in real time; The decision control subsystem has a built-in ANFIS-TOPSIS hybrid algorithm. Based on the data from the monitoring subsystem, it calculates the spontaneous combustion risk and selects the best fire prevention and extinguishing strategy from the preset candidate strategy set. The execution subsystem includes: Spraying side: First valve, used to control the flow rate of inhibitor; pressurization equipment, used to provide spraying pressure; inhibitor container, used to store gangue powder-water mixed inhibitor; delivery pipeline, used to connect each spraying component and deliver inhibitor; Nitrogen injection side: Rear spraying device for spraying inhibitor; second valve for controlling nitrogen flow; nitrogen storage chamber for storing high-purity nitrogen; nitrogen injection pipeline for transporting nitrogen to the goaf.

[0013] Furthermore, the monitoring subsystem includes: Signal acquisition bundle tube, used for real-time acquisition of gas samples from the working face; Bundle tubes are used to transport gas to analytical equipment; A multi-gas sensor for analyzing the composition of gases such as O2, CO, C2H4, and CH4; A pressure gauge is used to monitor changes in gas pressure.

[0014] Furthermore, the decision control subsystem includes: The data processor is used to run the ANFIS-TOPSIS algorithm and output the optimal fire prevention and suppression decision. A PLC control system is used to execute the instructions of the data processor and control the execution subsystem. The execution subsystem includes: Spraying side: First valve, used to control the flow rate of inhibitor; pressurization equipment, used to provide spraying pressure; inhibitor container, used to store gangue powder-water mixed inhibitor; delivery pipeline, used to connect each spraying component and deliver inhibitor; Nitrogen injection side: Rear spraying device for spraying inhibitor; second valve for controlling nitrogen flow; nitrogen storage chamber for storing high-purity nitrogen; nitrogen injection pipeline for transporting nitrogen to the goaf.

[0015] Furthermore, the instructions for responding to the decision control subsystem include: When the carbon monoxide concentration is continuously ≥50ppm, the spraying device behind the frame is activated. When an oxygen concentration of ≥18% or ethylene gas is detected, nitrogen injection into the goaf is initiated, with the goal of reducing the oxygen concentration to below 12%.

[0016] Furthermore, the decision control subsystem executes the ANFIS-TOPSIS hybrid algorithm to dynamically assess the risk of spontaneous combustion in the goaf and precisely control prevention and control measures, including the following steps: a. Multivariate data acquisition and preprocessing: Collect gas parameters in the goaf, construct a monitoring parameter vector, and perform normalization processing; (1) The data acquisition cycle is 5s, and the expression is: ; In the formula, For data collection cycle; (2) The physical parameters for the risk of spontaneous combustion of coal in the goaf at any given time are: ; in, Calculated using pressure gradient: ; In the formula, Permeability coefficient, For observation distance, The cross-sectional area of ​​the tunnel. This refers to the air leakage rate. (3) Data normalization processing, performing normalization on the 7-dimensional input. Normalization to : ; In the formula, for exist Time of the first The normalized values ​​of the parameters for exist Time of the first The original monitoring values ​​of each parameter, for In historical data, the first The maximum value of each parameter. for In historical data, the first The minimum value of each parameter. The parameter index has a value range from 1 to 7; in, Concentration detection generates a discrete indicator for triggering: ; In the formula, for The ethylene concentration exceeding the limit indicator variable at time [time]. The detection limit is determined by the equipment. The ANFIS output is: ; In the formula, The input vector is the normalized form. The normalized temperature. The normalized pressure difference The normalized air leakage intensity, The transpose operator converts a row vector into a column vector. b. ANFIS Risk Modeling: Input the normalized parameter vector into the ANFIS model, and the output will be a risk level representing the spontaneous combustion risk. ; (1) Input / output definitions: enter: Output, risk level of spontaneous combustion: ; Define risk level : ; In the formula, Let t represent the risk of spontaneous combustion at time t. Risk level of spontaneous combustion; (2) Fuzzy membership settings; For each input Set three fuzzy sets: low, medium, and high, respectively. Using Gaussian membership functions: ; In the formula, Input variables Belongs to the Fuzzy set membership degree This corresponds to the center value of the Gaussian function. To correspond to the width of the Gaussian function, For fuzzy set index; (3) Rule layer and post-rule; No. Rule 1: ; In the formula, For the first A fuzzy rule, , These are the normalized input variables (such as temperature, gas concentration, etc. mentioned above). , For the first In this rule, the corresponding fuzzy set of input variables ("low", "medium", "high") is represented by ∧, which is a logical AND operation, indicating that all conditions must be true simultaneously. For the first The output function of the rule, For the first Rule number 1 The linear coefficients of the input variables, For the first The constant term of the rule; Rule trigger strength: ; In the formula, For the first The trigger strength of a fuzzy rule; Normalization: ; In the formula, For the first The normalized trigger strength of the rule, For the first The trigger strength of the rule; ANFIS output: ; In the formula, for The risk of spontaneous combustion at any given moment. For the first The consequent of the rule outputs the function value; (4) Training objectives; If there is a historical spontaneous combustion event A, provide the historical fire warning / response records. Minimize the mean square error: ; In the formula, Mean square error, The total number of training samples, For the first The true risk label of each sample For the first The model predicts the risk level for each sample; If there is no historical spontaneous combustion event B, construct pseudo-labels using thresholds, including ethylene veto and O2 / CO thresholds; ; In the formula, for False risk labels at all times for Excessive weighting coefficients for CO out-of-limit state variable at time t. This is the weighting coefficient for oxygen exceeding the limit. The weighting factor for ethylene exceeding the limit. for The indicator variable for ethylene concentration exceeding the limit at any given time; Pick If ethylene is detected, nitrogen injection is initiated. c. TOPSIS Strategy Selection: Based on Risk Level The weights of TOPSIS evaluation indicators are dynamically adjusted to select the optimal fire prevention and suppression strategy from the candidate strategy set. (1) Candidate strategy set : Only observe and issue warnings, without taking any action / or at extremely low intensity; Low-intensity spraying; inhibitor spray flow rate = 20 L / min, duration = 30 min; High-intensity spraying; inhibitor spray flow rate = 50 L / min, duration = 60 min; Low-intensity nitrogen injection; nitrogen injection flow rate = 200 m³ / h, duration = 60 min; High-intensity nitrogen injection to achieve an oxygen concentration of less than 12%; nitrogen injection flow rate = 500 m³ / h, duration = 120 min; Low-intensity spraying combined with nitrogen injection; High-intensity spraying combined with nitrogen injection; Each strategy is associated with adjustable parameters: ; In the formula, For the first The parameter vector of each candidate strategy For spraying intensity, For nitrogen injection flow rate, Duration; (2) Hard constraint clipping; like Then the candidate set must include spraying types. ; like or Then the candidate set must contain nitrogen injection type. ; For all candidate strategies involving nitrogen injection, the objective constraint must be satisfied; therefore, the following must be predicted or set: ; In the formula, This is a predicted value for oxygen concentration. For the current moment, This represents the expected execution time of the strategy. Otherwise, the strategy is deemed infeasible and eliminated; (3) TOPSIS indicator system; For each candidate strategy, construct an index vector. ,in, To achieve the ability to reduce oxygen levels to meet standards, CO inhibition ability, For the time to take effect, For material / energy costs, To mitigate production disruptions, To ensure safety and controllability, a decision matrix is ​​formed. Rows represent strategies, and columns represent metrics; (4) Quantitative indicators; The effect of nitrogen injection on oxygen: Let the effective influence volume be... Mixing efficiency : ; Define the oxygen reduction target indicators: ; In the formula, For strategy The oxygen reduction capacity indicator; The empirical model for the exponential decay of CO suppression by spraying is as follows: ; ; In the formula, This is a predicted value for carbon monoxide concentration. For the spraying of inhibitors Suppression efficiency coefficient For strategy CO inhibition capacity index; Onset time / cost / disruption / safety: ; ; ; ; In the formula, For strategy The onset time indicator. For strategy The expected onset time, For strategy Material / energy cost indicators This is the cost coefficient per unit amount of inhibitor sprayed. The cost coefficient per unit nitrogen injection volume For strategy Production disturbance indicators. The disturbance coefficient of spraying intensity on production. The disturbance factor of nitrogen injection flow rate on production. For strategy Safety and controllability indicators, The penalty coefficient for the safety risks associated with high concentrations of methane. To predict the penalty coefficient for safety risks caused by excessively low oxygen concentration, For high concentration methane threshold, This is the lower limit of safe oxygen concentration for the operation. (5) TOPSIS standard calculation; Positive indicator: ; In the formula, The positiveized index value, The first decision matrix is ​​the first decision matrix. The first strategy The original values ​​of each indicator For indexing indicators, The first of all strategies The maximum value of each indicator. The first of all strategies The minimum value of each indicator; Normalization: ; In the formula, The index value is the normalized value; Weighted: ; In the formula, These are the elements of the weighted decision matrix. For the first Weighting coefficients for each indicator; Positive ideal solution / Negative ideal solution: ; In the formula, For the positive ideal solution, For a negative ideal solution, In the first The maximum value among all strategies for each metric. In the first The minimum value among all strategies for each metric; Distance and application progress: ; ; In the formula, For the first The Euclidean distance between each strategy and the positive ideal solution For the first The Euclidean distance between each strategy and the negative ideal solution. For the positive ideal solution in the th case The value of each indicator For the negative ideal solution in the th case The value of each indicator For the first The relative similarity of the strategies; Pick The strategy with the largest value is the optimal strategy. ; In the formula, for The optimal fire prevention and extinguishing strategy selected by the system at all times. For strategy indexing; (6) Dynamic regulation of ANFIS→TOPSIS; Using ANFIS risk level To dynamically adjust the TOPSIS weights, the remaining weights are supplemented using normalization; When approaching a danger zone, the system selects a combined and high-intensity strategy; ; ; In the formula, The weighting of the oxygen reduction target achievement indicator dynamically changes with the risk level R. The weights of the CO suppression capacity index are dynamically changed with the risk level R. The weights of material / energy cost indicators are dynamically adjusted according to the risk level R. The weights of the production disturbance index are dynamically changed with the risk level R. The spontaneous combustion risk level output by the ANFIS model; d. Instruction Mapping and Execution: Mapping the optimal strategy into specific control instructions and sending them to the execution subsystem; (1) Control output vector and send it to PLC ; In the formula, for Control command vectors sent to the PLC at all times for The required inhibitor spraying intensity as specified in the time instruction. for The nitrogen injection flow rate required by the time command. for The duration of the measures required by the time-based instruction. These correspond to the opening degrees of the first valve, the booster, the rear sprayer, and the second valve in the diagram, with an opening range of 0-100%. (2) Mapping of optimal policy to action; like In the low-pressure spray mode, the first valve is set to 30% opening, the booster equipment is started, the second valve is closed, and the spray lasts for 30 minutes. ; In the formula, The optimal strategy selected by the system. A low-intensity spraying strategy, The execution duration specified in the instruction. For strategy Preset duration; like In this case, low nitrogen injection is implemented, meaning the first valve is closed, the booster equipment stops, and the second valve is opened to 40% for 60 minutes. ; In the formula, For low-intensity nitrogen injection strategy, The nitrogen injection flow rate specified in the instruction. For strategy Preset nitrogen injection flow rate, For strategy Preset duration; like The high-intensity combination involves the first valve opening to 80%, the booster equipment starting, the second valve opening to 90%, and a duration of 120 minutes. ; In the formula, For strategy Preset spray intensity, , for strategy Preset nitrogen injection flow rate, For strategy Preset duration; Other situations: ,valve closure; High-pressure spraying, i.e., the first valve is set to 80% opening, the booster equipment is started, the second valve is closed, and the duration is 60 minutes; High nitrogen injection means that the first valve is closed, the booster equipment is stopped, the second valve is opened to 90%, and the duration is 120 minutes. Low-intensity combination, i.e., the first valve is opened to 30%, the booster equipment is started, the second valve is opened to 40%, and the duration is 60 minutes; (3) Hard trigger forced set overwrite; Regardless of the TOPSIS output, execution is forced as long as the triggering condition is met: ; ; The nitrogen injection target is written as a closed-loop constraint, namely, the first valve is fully open (100%), the booster equipment starts, and the duration is 60 minutes: ; Complete dynamic control of fire prevention and extinguishing.

[0017] In step S4, the windbreak wall is constructed of shale bricks and cement mortar. A thick intumescent fire-retardant coating is applied to the side of the wall facing the goaf to achieve both fire resistance and sealing. A drainage hole is pre-drilled at the bottom of the wall to drain accumulated water from the goaf. A monitoring hole is pre-drilled in the middle for inserting a gas detection device; its height is the same as the roadway, its width is 400mm wider than the roadway, and its thickness is ≥500mm. The main body of the windbreak curtain is made of 0.8mm thick flame-retardant canvas, with galvanized steel wire rope as the suspension load. Wide buttonholes are sewn around the canvas for threading and securing the steel wire rope. An openable observation window is provided in the middle for inspecting the goaf.

[0018] In step S5, step-by-step bypass grouting is adopted. As the working face advances a certain distance, high-polymer solidified foam is injected into the side wall of the goaf through preset boreholes to form an isolation wall. After grouting at that point is completed, the grouting pipe is withdrawn; the working face continues to advance, and when it advances to the next predetermined distance, the next isolation wall is constructed; this cycle is repeated until an isolation zone is formed.

[0019] Combining all the above technical solutions, the beneficial effects of this invention are as follows: First, this invention proposes a collaborative fire prevention and extinguishing method based on the integrated improvement of roadway layout and working face fire prevention and extinguishing system, which combines roadway layout and fire prevention and extinguishing measures under the condition of isolated coal pillar re-mining. Simultaneously, this invention also constructs an intelligent system for monitoring and actively preventing spontaneous combustion of coal in the goaf, integrating fire prevention and extinguishing monitoring, spraying, and nitrogen injection.

[0020] Secondly, this invention proposes a collaborative fire prevention and extinguishing method based on the integrated improvement of roadway layout and working face fire prevention and extinguishing system, which combines "blocking-isolation-inerting". The roadway location is selected based on the characteristics of isolated coal pillars, and an optimized fire prevention and extinguishing system is adopted: physical blocking is used during roadway excavation, dynamic inerting of the goaf and spraying suppression at the working face are carried out during mining, and a full-process intelligent monitoring system is used. The combination of these two methods achieves full-cycle prevention and control of coal seam spontaneous combustion risk.

[0021] Third, this invention can improve resource recovery rate: by arranging the mining roadway within the remaining coal pillar and reserving small coal pillars, combined with the construction of lateral isolation walls during coal release on both sides, the resources of the remaining coal pillar can be recovered by 15% to 25%. This invention reduces fire prevention and extinguishing costs: traditional grouting and nitrogen injection technologies adopt a continuous operation mode, resulting in high material and energy costs. This invention achieves precise spraying and nitrogen injection through the ANFIS-TOPSIS intelligent system, saving more than 30% of inhibitor usage and more than 25% of nitrogen usage compared to traditional methods, resulting in annual direct costs of approximately 2-3 million yuan for fire prevention and extinguishing per working face. This invention can avoid production stoppage losses: once a coal seam spontaneous combustion accident occurs, it can lead to the closure of the working face at best, and the shutdown of the mine at worst. This invention, through full-cycle three-dimensional prevention and control, minimizes the risk of spontaneous combustion, avoiding production stoppage losses (typically tens of millions of yuan per month) and fire extinguishing engineering investment caused by a single accident.

[0022] Fourth, this invention proposes a five-in-one collaborative fire prevention and extinguishing system integrating "roadway layout - tunneling sealing - mining inerting - corner isolation - lateral blocking". In existing technologies at home and abroad, roadway system design (such as coal pillar retention) and fire prevention and extinguishing measures (such as nitrogen injection and grouting) are often separated: mining engineers only consider the convenience of tunneling and mining, while fire prevention and extinguishing engineers passively deal with existing air leakage channels. This invention is the first to arrange roadways inside the remaining coal pillars, reducing coal exposure from the source, and organically integrating spraying / grouting sealing during tunneling, intelligent inerting during mining, double isolation of corners, and lateral isolation walls when coal is released from both sides, forming a systematic prevention and control scheme covering the entire mine cycle, filling the gap in integrated design of "mining and tunneling - fire prevention and extinguishing".

[0023] Fifth, this invention solves the problem of controlling the risk of spontaneous combustion at the source in the re-mining of isolated coal pillars. Isolated coal pillars are surrounded by goaf areas, with concentrated ground pressure and well-developed fissures, making them extremely prone to spontaneous combustion. Traditional methods can only passively seal them after the roadway is formed, often only treating the symptoms, not the root cause. The industry has long desired to "integrate fire prevention and extinguishing concepts into the design stage," but this has not been achieved due to the lack of a systematic layout method. This invention significantly reduces the cutting and exposure of the coal pillar by directly arranging the mining roadway inside the abandoned coal pillar and reserving a 2-3m small coal pillar, thereby reducing the oxidation contact area from the source and achieving, for the first time, the source synergy between "mining design" and "fire prevention and extinguishing design."

[0024] This invention enables "on-demand" rather than "one-size-fits-all" governance measures. The extent and degree of spontaneous combustion in the "oxidation zone" of the goaf dynamically change as the working face advances. Traditional nitrogen injection and spraying, using fixed parameters for continuous operation, are either insufficiently effective or highly wasteful. The industry has long desired an intelligent system that can "measure and control as mining progresses," but due to the closed environment and complex parameter coupling in the goaf, closed-loop control has remained elusive. This invention integrates multi-dimensional gas parameters through an ANFIS model, quantifying expert experience into fuzzy rules and outputting the spontaneous combustion risk level in real time. Then, by dynamically selecting the current optimal strategy through TOPSIS and directly controlling the valve opening, the "on-demand inerting" of the oxidation zone in the goaf was achieved for the first time, overcoming this dynamic control problem. Attached Figure Description

[0025] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure; Figure 1 This is a flowchart of the planning method for coordinated remining of isolated coal pillar resources in roadways and fire prevention and extinguishing, provided in an embodiment of the present invention. Figure 2 This is a tunnel layout diagram provided in an embodiment of the present invention; Figure 3 This is a flowchart of the crack sealing treatment method provided in the embodiments of the present invention; Figure 4 This is a schematic diagram of the method of spraying inhibitors behind the frame and injecting nitrogen into the goaf provided in an embodiment of the present invention; Figure 5 This is an architecture diagram of the isolated coal pillar resource roadway system and the fire prevention and extinguishing collaborative remining planning system provided in the embodiments of the present invention; In the diagram: 1. Residual coal pillar; 2. Goaf; 3. Inorganic solidified foam material; 4. Flame-retardant nylon mesh; 5. Polymer foam material; 6. Roof; 7. Sealed fracture layer; 8. Roof support; 9. Support; 10. Working face; 11. Air intake side; 12. Air return side; 13. Signal acquisition bundle tube; 14. Spraying device behind the support; 15. Pressure gauge; 16. Conveying pipeline; 17. First valve; 18. Pressurization equipment; 19. Inhibitor container; 20. PLC control system; 21. Data processor; 22. Multi-element gas sensor; 23. Bundle tube; 24. Second valve; 25. Nitrogen storage chamber; 26. Nitrogen injection pipeline. Detailed Implementation

[0026] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0027] The innovation of this invention lies in its proposal of an improved integrated "blocking-isolation-inerting" collaborative fire prevention and extinguishing method based on roadway layout and working face fire prevention and extinguishing system. This method integrates roadway layout and fire prevention and extinguishing measures under the condition of isolated coal pillar re-mining. This invention also constructs an intelligent system for monitoring and actively preventing spontaneous combustion of coal in the goaf, integrating fire prevention and extinguishing monitoring, spraying, and nitrogen injection.

[0028] Examples, such as Figure 1 As shown, the method for coordinating the planning of isolated coal pillar resource roadway system and fire prevention and extinguishing for re-mining provided in this embodiment of the invention includes the following steps: S1. Based on the geological data of the mine, assess the conditions of the coal seam to be mined again, arrange the mining roadway in the remaining coal pillar 1, and reserve a small coal pillar with a width of 2m to 3m. S2. During tunnel excavation, inorganic solidified foam material is sprayed onto the surface of the surrounding rock to form an inorganic solidified foam barrier layer and to seal the cracks in the surrounding rock. For the cracks in the roof slab 6 and the sidewalls of the roadway, high-polymer foam material 5 is injected to form a sealed sealing layer 7; for the gap between the roof support 8 and the support 9 top beam and the roof slab 6 of the working face 10, flame-retardant nylon mesh 4 and fireproof cotton are used for filling. S3. During the roadway mining period, a combination of spraying inhibitors after the support frame and injecting nitrogen into the goaf is adopted as mining and prevention measures are implemented. An intelligent system for monitoring and proactive joint prevention of spontaneous combustion of coal in the goaf based on monitoring data is constructed to dynamically regulate the spraying and nitrogen injection measures. During tunnel excavation, the following measures will be implemented: During tunnel excavation, an inorganic solidified foam material will be sprayed into the tunnel interior to form a continuous inorganic solidified foam barrier layer with a certain strength and density, preventing spontaneous combustion of residual coal in goaf 2. If the surrounding rock of the tunnel is severely damaged and the roof 6 shows obvious cracks, the cracks will be sealed.

[0029] S4. Fireproof and sealed double isolation facilities consisting of windbreak walls and / or windbreak curtains shall be installed at the 11th corner of the air inlet side and the 12th corner of the air return side of the working face 10. During the roadway mining, the following measures were taken: During the mining of working face 10, a mining-as-you-go prevention system combining "post-support spraying of inhibitors + nitrogen injection into the goaf" was adopted to cover the "oxidation zone" of working face 10 goaf and suppress the exothermic oxidation reaction of residual coal. An intelligent system for monitoring and proactively preventing spontaneous combustion of coal in the goaf was constructed based on the ANFIS-TOPSIS hybrid algorithm. This system, combined with "post-support spraying + inhibitors," was used to optimize measures and dynamically control the risk of spontaneous combustion in goaf 2.

[0030] S5. If coal is discharged from both sides of working face 10, a stepping polymer solidified foam isolation wall is constructed behind support 9 to form a lateral isolation zone in goaf 2.

[0031] Double isolation facilities consisting of "windbreak walls + windbreak curtains" are installed at the corners of the air intake and return air. When the coal seam thickness is greater than 5 meters, a scheme of releasing coal from both sides will be used to improve the resource recovery rate. This scheme aims to improve the resource recovery rate by ensuring fire prevention, gas control, and support, through scientific technical parameters and strict on-site management. If coal is discharged from both sides of working face 10, a lateral isolation zone is constructed in goaf 2 as a fire prevention and extinguishing design plan for coal discharge from both sides.

[0032] In step S1, the survey of mine data mainly includes the contents shown in Table 1.

[0033] Table 1. Analysis Report on the Tendency of Spontaneous Combustion in Coal Seams

[0034] In step S2, the roadway is arranged on both sides of the remaining coal pillar 1, with 2-3 small coal pillars left. The core reason is that this coal seam has a Class II spontaneous combustion tendency and the shortest spontaneous combustion period is only 63 days. This arrangement aims to minimize the cutting and exposure of the coal pillars, reduce the amount of remaining coal and the oxidation contact area by reducing the size of the coal pillars, thereby controlling the risk of coal spontaneous combustion from the source. It is the most direct and economical fire prevention and extinguishing engineering measure to deal with the spontaneous combustion characteristics of this coal seam.

[0035] In step S31, inorganic solidified foam material 3 is sprayed into the working face roadway to form a continuous inorganic solidified foam barrier layer with a certain strength and density, preventing spontaneous combustion of residual coal in the goaf 2. Figure 1 As shown; the inorganic curing material is made by fusing rapid-hardening silicate cement, fly ash, foaming agent, stabilizer and quick-setting agent, with a water-cement ratio of 0.8 and a spraying thickness of 100mm. In areas with obvious crack development, it can be sprayed up to 150mm. The spraying sequence is top first and then side.

[0036] In step S32, the method for sealing the crack is as follows: Figure 3As shown. To seal the cracks in the top and sides of the roadway, high-polymer foam material 5 is injected into the cracks to form a sealed sealing layer; the gap between the support beam and the roof slab 6 is filled with flame-retardant nylon mesh 4 and fireproof cotton to reduce air leakage through the gap of the support 9, block the contact channel between the residual coal in the goaf 2 and the fresh air flow, and inhibit the accumulation of oxidation heat.

[0037] The key technical parameters for the sealed sealing layer formed by injecting polymer foam material 5 into the crack are controlled as follows: The expansion ratio of the polymer foam material 5 is controlled between 15 and 30 times to ensure that it can fully fill micro-cracks without causing destructive stress to the surrounding rock due to excessive expansion. The reaction time should be 30 to 90 seconds to adapt to the rapid plugging operation rhythm downhole. After curing, the compressive strength of the plugging layer is not less than 0.8 MPa, possessing a certain load-bearing and deformation resistance. Its airtightness requirement is that, under a pressure difference of 0.1 MPa, the air leakage rate per unit area is less than 0.005 m³ / s. 3 / (m 2 (min). At the same time, the material should have flame-retardant and antistatic properties, meet coal mine safety standards, and have a bonding strength with the coal body greater than 0.5MPa to ensure the long-term effectiveness of the sealing body under the deformation of the surrounding rock.

[0038] The expansion ratio of the polymer foam material 5 is limited to between 15 and 30 times. This is to achieve the best balance between fully filling the micro-cracks and maintaining the structural strength of the solidified body. If the expansion ratio is less than 15 times, the material will not foam sufficiently and will have poor fluidity, failing to penetrate deeply and fill the tortuous network of micro-cracks, resulting in incomplete sealing, leaving air leakage channels, and losing its airtightness. If the expansion ratio is greater than 30 times, the internal bubble walls of the material will be too thin and the structure will be loose. The compressive strength after curing will be difficult to meet the bearing requirement of 0.8 MPa. At the same time, excessive expansion pressure may have a splitting effect on the originally broken surrounding rock, which may instead expand the cracks or damage the integrity of the rock mass, thereby causing more serious air leakage and spontaneous combustion risks.

[0039] The reaction time of the polymer foam material 5 is controlled between 30 and 90 seconds to ensure that the material can fully penetrate into the depth of the crack and quickly solidify at the predetermined location. If the reaction time is less than 30 seconds, the material will solidify rapidly as soon as it is injected into the crack, and will not be able to penetrate deep, only forming a "surface seal", which is easily crushed by mining pressure and will fail. If the reaction time is longer than 90 seconds, the material will flow out of the crack under the action of gravity, and will not be able to accumulate and solidify at the designated location, resulting in material waste and poor sealing effect.

[0040] Flame-retardant nylon mesh 4 uses mesh sizes ranging from 10mm×10mm to 20mm×20mm, with a unit area weight of not less than 80g / m². 2Its oxygen index must be ≥28%, and it must possess antistatic properties to serve as an initial framework and insulation. Fireproof cotton should be made of mining-grade aluminosilicate fiber, with its thickness dynamically adjusted according to the gap size, typically 30~100mm, and a density range of 80~120kg / m³. 3 The maximum operating temperature is not lower than 1000℃. During construction, first lay and fix the nylon mesh along the upper part of the support beam to form a pocket shape; then tightly and evenly fill all the gaps between the nylon mesh and the top plate 6 with fireproof cotton until there is no obvious looseness or gaps. Adjacent fireproof cotton blocks should be overlapped or wedged together, with an overlap length of not less than 50mm, to ensure continuous sealing and ultimately form a composite isolation layer that combines flexibility, fire resistance, and high density.

[0041] In step S4, the method of spraying inhibitors behind the frame and injecting nitrogen into the goaf is as follows: Figure 4 As shown. The inhibitor is made of low-cost gangue powder and water, with a weight ratio of gangue powder:water of 1:0.6~1:0.7. Through physical coverage, it blocks coal-oxygen contact and inhibits the oxidation chain reaction, significantly reducing the risk of spontaneous combustion. The focus is on covering the goaf 2 behind the support frame, the end triangle point, and the coal pillar line. Nitrogen injection equipment is installed in the roadway to inject high-purity nitrogen to replace oxygen and gas in the area, reducing the oxygen concentration below the critical value for coal spontaneous combustion (≤12%), fundamentally blocking the oxidation reaction. Nitrogen injection pipeline 26 is installed on the non-production side of the working face conveyor roadway, and preventative nitrogen injection is carried out on newly generated goaf 2 using a continuous injection method. Simultaneously, a monitoring system is provided, combined with the spraying and nitrogen injection behind the support frame, forming a smart system for monitoring and proactively preventing coal spontaneous combustion in the goaf. Figure 4 As shown.

[0042] exist Figure 4 During the process, as the goaf 2 advances, it is monitored by the signal acquisition tube 13. Gas enters the signal acquisition tube 13, information is collected, and transmitted through the tube 23 to the multi-element gas sensor 22. The gas composition is analyzed, and its concentration is determined by the pressure gauge 15. This information is then transmitted to the data processor 21, which identifies the appropriate fire prevention and extinguishing method. Based on the "Technical Specification for Monitoring and Early Warning of Spontaneous Fires in Goaf Areas of Underground Coal Mines" (NB / T 11646-2024) and the actual field conditions, the carbon monoxide (CO) concentration threshold is set at ≥50 × 10⁻⁶. -6When the concentration is (ppm), the first valve 17 and the pressurization device 18 are opened through the PLC control system 20, and the inhibitor is injected from the inhibitor container 19 into the post-frame spraying device 14. The post-frame spraying device 14 is then activated to enable physical isolation, so as to cover the coal body and block the oxidation chain. When the oxygen O2 threshold is ≥18% in the oxidation zone of goaf 2 or ethylene (C2H4) gas is detected (regardless of concentration), the nitrogen inerting system of goaf 2 is immediately activated. The second valve 24 is opened through the PLC control system 20, and the nitrogen in the nitrogen storage chamber 25 is injected into goaf 2 through the nitrogen injection pipeline 26.

[0043] System architecture such as Figure 4 and Figure 5 As shown, the functional definitions of each component are as follows: The monitoring subsystem includes: a signal acquisition tube 13 for real-time acquisition of gas samples from the working face 10; a tube 23 for transmitting gas to the analysis equipment; a multi-element gas sensor 22 for analyzing the gas composition of O2, CO, C2H4, and CH4; and a pressure gauge 15 for monitoring gas pressure changes.

[0044] The decision control subsystem includes: a data processor 21, which runs the ANFIS-TOPSIS algorithm and outputs the optimal fire prevention and extinguishing decision; and a PLC control system 20, which executes the instructions of the data processor 21 and controls the execution system.

[0045] The execution subsystem includes: Spraying side: First valve 17, used to control the flow rate of inhibitor; booster device 18, used to provide spraying pressure; inhibitor container 19, used to store gangue powder-water mixed inhibitor; delivery pipeline 16, used to connect each spraying component and deliver inhibitor; Nitrogen injection side: Rear spraying device 14, used to spray inhibitor; second valve 24, used to control nitrogen flow; nitrogen storage chamber 25, used to store high-purity nitrogen; nitrogen injection pipeline 26, used to transport nitrogen to goaf 2.

[0046] Triggering logic: 1. When CO is consistently ≥50×10 -6 (This can be understood as a 50ppm level in engineering terms): The PLC starts the spraying chain (17, 18, 14, etc.), injects the inhibitor into the spraying device 14 after the frame, and achieves physical coverage and oxygen isolation.

[0047] 2. When O2 ≥ 18% (within the oxidation zone) or C2H4 is detected (regardless of concentration): PLC starts the nitrogen injection link (24→25→26) to inertize goaf 2.

[0048] 3. Nitrogen injection target: Reduce the oxygen concentration to below the critical value for coal spontaneous combustion (≤12%).

[0049] Algorithm steps: 1. Multi-source data acquisition and preprocessing; (1) The data acquisition cycle is 5s, and the expression is: ; In the formula, For data collection cycle; (2) The physical parameters for the risk of spontaneous combustion of coal in the goaf at any given time are: ; in, Calculated using pressure gradient: ; In the formula, Permeability coefficient, For observation distance, The cross-sectional area of ​​the tunnel. This refers to the air leakage rate. (3) Data normalization processing, performing normalization on the 7-dimensional input. Normalization to : ; In the formula, for exist Time of the first The normalized values ​​of the parameters for exist Time of the first The original monitoring values ​​of each parameter, for In historical data, the first The maximum value of each parameter. for In historical data, the first The minimum value of each parameter. The parameter index has a value range from 1 to 7; in, Concentration detection generates a discrete indicator for triggering: ; In the formula, for The ethylene concentration exceeding the limit indicator variable at time [time]. The detection limit is determined by the equipment. The ANFIS output is: ; In the formula, The input vector is the normalized form. The normalized temperature. The normalized pressure difference The normalized air leakage intensity, The transpose operator converts a row vector into a column vector. 2. ANFIS: Spontaneous Combustion Risk Modeling and Output; (1) ANFIS input / output definition; enter: Output, risk level of spontaneous combustion: ; Define risk level : ; In the formula, Let be the risk level of spontaneous combustion at time t. Risk level of spontaneous combustion; (2) Fuzzy membership settings; For each input Set three fuzzy sets: low, medium, and high, respectively. Using Gaussian membership functions: ; In the formula, Input variables Belongs to the Fuzzy set membership degree This corresponds to the center value of the Gaussian function. To correspond to the width of the Gaussian function, For fuzzy set index; (3) Rule layer and post-rule; No. Rule 1: ; In the formula, For the first A fuzzy rule, , These are the normalized input variables (such as temperature, gas concentration, etc. mentioned above). , For the first In this rule, the corresponding fuzzy set of input variables ("low", "medium", "high") is represented by ∧, which is a logical AND operation, indicating that all conditions must be true simultaneously. For the first The output function of the rule, For the first Rule number 1 The linear coefficients of the input variables, For the first The constant term of the rule; Rule trigger strength: ; In the formula, For the first The trigger strength of a fuzzy rule; Normalization: ; In the formula, For the first The normalized trigger strength of the rule, For the first The trigger strength of the rule; ANFIS output: ; In the formula, for The risk of spontaneous combustion at any given moment. For the first The consequent of the rule outputs the function value; (4) Training objectives; If there is a historical spontaneous combustion event A, provide the historical fire warning / response records. Minimize the mean square error: ; In the formula, Mean square error, The total number of training samples, For the first The true risk label of each sample For the first The model predicts the risk level for each sample; If there is no historical spontaneous combustion event B, construct pseudo-labels using thresholds, including ethylene veto and O2 / CO thresholds; ; In the formula, for False risk labels at all times for Excessive weighting coefficients for CO out-of-limit state variable at time t. This is the weighting coefficient for oxygen exceeding the limit. The weighting factor for ethylene exceeding the limit. for The indicator variable for ethylene concentration exceeding the limit at any given time; Pick If ethylene is detected, nitrogen injection is initiated. 3. TOPSIS joint defense strategy selection and intensity setting; (1) Candidate strategy set; : Only observe and issue warnings, without taking any action / or at extremely low intensity; Low-intensity spraying (valve 17 open, pump 18 low speed, device 14); inhibitor spraying flow rate = 20L / min, duration = 30min; High-intensity spraying; inhibitor spray flow rate = 50 L / min, duration = 60 min; Low-intensity nitrogen injection (valve 24 open, low flow rate); nitrogen injection flow rate = 200 m³ / h, duration = 60 min; High-intensity nitrogen injection (to achieve an oxygen concentration of less than 12%); nitrogen injection flow rate = 500 m³ / h, duration = 120 min; Low-intensity spraying combined with nitrogen injection; High-intensity spraying combined with nitrogen injection; Each strategy is associated with adjustable parameters: ; In the formula, For the first The parameter vector of each candidate strategy Spraying intensity, in L / min; This refers to the nitrogen injection flow rate, expressed in m³ / h. Duration, in minutes; (2) Hard constraint clipping; like Then the candidate set must include spraying types. ; like or Then the candidate set must contain nitrogen injection type. ; For all candidate strategies involving nitrogen injection, the objective constraint must be satisfied; therefore, the following must be predicted or set: ; In the formula, This is a predicted value for oxygen concentration. For the current moment, This represents the expected execution time of the strategy. Otherwise, the strategy is deemed infeasible and eliminated; (3) TOPSIS indicator system; For each candidate strategy, construct an index vector. ,in, To achieve the target oxygen concentration (efficiency-oriented, the higher the better, target oxygen concentration less than 12%). CO suppression capability (efficiency type). For the onset time (cost-based, the shorter the better). For material / energy consumption costs (cost type). To address production disruptions (cost-related). For safety and controllability (profitability-oriented, considering risks such as high gas / oxygen deficiency, emphasizing the conditions of high gas isolated islands), a decision matrix is ​​formed. Rows represent strategies, and columns represent metrics; (4) Quantitative indicators; The effect of nitrogen injection on oxygen: Let the effective influence volume be... Mixing efficiency : ; Define the oxygen reduction target indicators: ; In the formula, For strategy The oxygen reduction capacity indicator; The empirical model for the exponential decay of CO suppression by spraying is as follows: ; ; In the formula, This is a predicted value for carbon monoxide concentration. For the spraying of inhibitors Suppression efficiency coefficient For strategy CO inhibition capacity index; Onset time / cost / disruption / safety: ; ; ; ; In the formula, For strategy The onset time indicator. For strategy The expected onset time, For strategy Material / energy cost indicators This is the cost coefficient per unit amount of inhibitor sprayed. The cost coefficient per unit nitrogen injection volume For strategy Production disturbance indicators. The disturbance coefficient of spraying intensity on production. The disturbance factor of nitrogen injection flow rate on production. For strategy Safety and controllability indicators, The penalty coefficient for the safety risks associated with high concentrations of methane. To predict the penalty coefficient for safety risks caused by excessively low oxygen concentration, For high concentration methane threshold, This is the lower limit of safe oxygen concentration for the operation. (5) TOPSIS standard calculation; (a) Positive indicator: ; In the formula, The positiveized index value, The first decision matrix is ​​the first decision matrix. The first strategy The original values ​​of each indicator For indexing indicators, The first of all strategies The maximum value of each indicator. The first of all strategies The minimum value of each indicator; (b) Normalization: ; In the formula, The index value is the normalized value; (c) Weighted: ; In the formula, These are the elements of the weighted decision matrix. For the first Weighting coefficients for each indicator; (d) Positive ideal solution / Negative ideal solution: ; In the formula, For the positive ideal solution, For a negative ideal solution, In the first The maximum value among all strategies for each metric. In the first The minimum value among all strategies for each metric; (e) Distance and application progress: ; ; In the formula, For the first The Euclidean distance between each strategy and the positive ideal solution For the first The Euclidean distance between each strategy and the negative ideal solution. For the positive ideal solution in the th case The value of each indicator For the negative ideal solution in the th... The value of each indicator For the first The relative similarity of the strategies; Pick The strategy with the largest value is the optimal strategy. ; In the formula, for The optimal fire prevention and extinguishing strategy selected by the system at all times. For strategy indexing; (6) Dynamic regulation of ANFIS→TOPSIS; Using ANFIS risk level The TOPSIS weights are dynamically adjusted, with higher risk levels emphasizing effectiveness and de-emphasizing cost; the remaining weights are adjusted using normalization. This allows for... When approaching a danger zone, the system tends to choose combined and high-intensity strategies.

[0050] ; ; In the formula, The weighting of the oxygen reduction target achievement indicator dynamically changes with the risk level R. The weights of the CO suppression capacity index are dynamically changed with the risk level R. The weights of material / energy consumption cost indicators are dynamically changed with the risk level R. The weights of the production disturbance index are dynamically changed with the risk level R. The spontaneous combustion risk level output by the ANFIS model; The remaining weights are supplemented by normalization. This makes the system more inclined to choose joint and high-intensity strategies when approaching the danger zone.

[0051] 4. Constraint verification + PLC execution mapping; (1) Control output vector and send it to PLC ; In the formula, for Control command vectors sent to the PLC at all times for The required inhibitor spraying intensity as specified in the time instruction. for The nitrogen injection flow rate required by the time command. for The duration of the measures required by the time-based instruction. These correspond to the opening degrees of the first valve 17, the booster 18, the rear sprayer 14, and the second valve 24 in the diagram, respectively, with an opening range of 0-100%. (2) Mapping of optimal policy to action; like In the low-pressure spray mode, the first valve 17 is set to 30% opening, the booster equipment 18 is started, and the second valve 24 is closed, lasting for 30 minutes. ; In the formula, The optimal strategy selected by the system. A low-intensity spraying strategy, The execution duration specified in the instruction. For strategy Preset duration; like In this case, low nitrogen injection is implemented, meaning the first valve 17 is closed, the booster equipment 18 is shut down, and the second valve 24 is opened to 40% for a duration of 60 minutes. ; In the formula, For low-intensity nitrogen injection strategy, The nitrogen injection flow rate specified in the instruction. For strategy Preset nitrogen injection flow rate, For strategy Preset duration; like The high-intensity combination involves the first valve (17) opening to 80%, the booster equipment (18) starting, and the second valve (24) opening to 90%, lasting for 120 minutes. ; In the formula, For strategy Preset spray intensity, , for strategy Preset nitrogen injection flow rate, For strategy Preset duration; The same applies to other cases: ,valve closure; High-pressure spraying, i.e., the first valve 17 is set to 80% opening, the booster equipment 18 is started, the second valve 24 is closed, and the duration is 60 minutes; High nitrogen injection, i.e., the first valve 17 is closed, the booster equipment 18 is stopped, the second valve 24 is set to 90% opening, and the duration is 120 minutes; Low-intensity combination, namely, the first valve 17 is opened to 30%, the booster equipment 18 is started, the second valve 24 is opened to 40%, and the duration is 60 minutes; (3) Hard trigger forced set overwrite; Regardless of the TOPSIS output, it will be forcibly executed as long as the triggering condition is met: ; ; The nitrogen injection target is written as a closed-loop constraint, namely, the first valve 17 is fully open (100%), the booster equipment 18 is started, and the duration is 60 minutes: ; Based on the above logic, dynamic control of fire prevention and extinguishing is achieved.

[0052] In step S5, windbreak walls or wind curtains are constructed in the air intake and return corners of the roadway. The main body of the windbreak wall is constructed of shale bricks and cement mortar. A thick intumescent fireproof coating is applied to the side of the wall facing the goaf 2 to ensure both fireproof and sealing performance. A drainage hole is reserved at the bottom of the wall to drain water accumulated in the goaf 2. A monitoring hole is reserved in the middle to facilitate the insertion of a gas detection device. Its height is consistent with the roadway, its width is 400mm wider than the roadway, and its thickness is ≥500mm. The main body of the wind curtain is made of 0.8mm thick flame-retardant canvas, with galvanized steel wire rope as the suspension load. Wide buttonholes are sewn around the canvas for threading and fixing the steel wire rope. An openable observation window is set in the middle to facilitate inspection of the goaf 2.

[0053] Compared to traditional sealed walls that only have a simple windproof function, the windproof wall constructed with shale bricks and intumescent fireproof coating achieves high-strength fireproof sealing while integrating a bottom drainage hole and a central monitoring hole. This solves the problems of water accumulation in the goaf area 2, which cannot be drained and gas monitoring is difficult in real time. Combined with a windproof curtain suspended by flame-retardant canvas and steel wire rope, and equipped with an openable observation window, it overcomes the shortcomings of traditional fixed sealed walls that cannot dynamically inspect the internal condition of the goaf area 2, and achieves flexible sealing and convenient inspection of corner areas, significantly improving the practicality and systematic nature of fire prevention and extinguishing facilities.

[0054] The main purpose of rear coal dumping on both sides is to improve coal recovery rate and reduce resource waste, but it poses a certain risk of air leakage. If required by the mine, a lateral isolation zone is constructed in the area behind the support 9, adjacent to the edge of the goaf 2. A step-by-step bypass grouting method is used. As the working face 10 advances a certain distance, a large amount of high-polymer solidified foam is injected into the side wall of the collapsed goaf 2 behind the support 9 through pre-drilled holes. This forms an isolation wall with a certain width and density, sealing all possible air leakage gaps. After grouting at this point is completed, the grouting pipe is withdrawn; the working face 10 continues to advance, and when it advances to the next predetermined distance, the above steps are repeated to construct the next isolation wall; this cycle continues until a continuously extending, airtight isolation zone is formed.

[0055] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention and within the spirit and principles of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for coordinating the planning of roadway systems for isolated coal pillar resources with fire prevention and extinguishing for re-mining, characterized in that, The method includes the following steps: S1. Based on the geological data of the mine, assess the conditions of the coal seam to be mined again, arrange the mining roadway in the left coal pillar (1), and reserve a small coal pillar with a width of 2m~3m. S2. During tunnel excavation, inorganic solidified foam material (3) is sprayed onto the surface of the surrounding rock to form an inorganic solidified foam barrier layer and to seal the cracks in the surrounding rock. S3. During the roadway mining period, a combination of spraying inhibitors after the frame and injecting nitrogen into the goaf (2) is adopted to prevent and control the spontaneous combustion of coal in the goaf (2) as it is mined. An intelligent system for monitoring and active joint prevention of spontaneous combustion of coal in the goaf (2) based on monitoring data is constructed to dynamically regulate the spraying and nitrogen injection measures. S4. Fireproof and sealed double isolation facilities consisting of windbreak walls and / or windbreak curtains are installed at the corners of the air inlet side (11) and the return air side (12) of the working face (10). S5. If coal is released from both sides of the working face (10), a step-like polymer solidified foam isolation wall is constructed behind the support (9) to form a lateral isolation zone of the goaf (2).

2. The method for coordinating remining of isolated coal pillar resource roadways with fire prevention and extinguishing as described in claim 1, characterized in that, In step S2, the sealing treatment of the surrounding rock fissures includes: For the cracks in the roof (6) and sidewalls of the roadway, inject polymer foam material (5) to form a sealed sealing layer (7); for the gap between the roof support (8) and the support (9) and the roof (6), use flame-retardant nylon mesh (4) and fireproof cotton to fill the gap.

3. The method for coordinating remining of isolated coal pillar resource roadways with fire prevention and extinguishing as described in claim 2, characterized in that, The expansion ratio of the polymer foam material (5) is 15 to 30 times, the reaction time is 30 to 90 seconds, and the compressive strength of the sealing layer after curing is not less than 0.8 MPa; The flame-retardant nylon mesh (4) has a mesh size of 10mm×10mm to 20mm×20mm and an oxygen index ≥28%; the fireproof cotton is mining aluminum silicate fiber cotton with a filling thickness of 30mm~100mm and a density of 80kg / m³. 3 ~120kg / m 3 .

4. The method for coordinating remining of isolated coal pillar resource roadways with fire prevention and extinguishing as described in claim 1, characterized in that, In step S3, the intelligent system for monitoring and proactively preventing spontaneous combustion of coal in the goaf (2) includes: The monitoring subsystem is used to collect and analyze the gas composition and concentration in the goaf (2) in real time; The decision control subsystem has a built-in ANFIS-TOPSIS hybrid algorithm. Based on the data from the monitoring subsystem, it calculates the spontaneous combustion risk and selects the best fire prevention and extinguishing strategy from the preset candidate strategy set. The execution subsystem, including the rear spraying device (14) and the nitrogen injection pipeline (26), is used to execute inhibitor spraying or goaf (2) nitrogen injection operations in response to the instructions of the decision control subsystem.

5. The method for planning the coordinated remining of isolated coal pillar resource roadways and fire prevention and extinguishing as described in claim 4, characterized in that, The monitoring subsystem includes: The signal acquisition bundle tube (13) is used to acquire gas samples from the working face in real time. Bundle tube (23) is used to transport gas to the analytical equipment; A multi-element gas sensor (22) is used to analyze the gas components of O2, CO, C2H4, and CH4; Pressure gauge (15) is used to monitor changes in gas pressure.

6. The method for planning the coordinated remining of isolated coal pillar resource roadways and fire prevention and extinguishing as described in claim 4, characterized in that, The decision control subsystem includes: Data processor (21) is used to run the ANFIS-TOPSIS algorithm and output the optimal fire prevention and suppression decision; The PLC control system (20) is used to execute the instructions of the data processor (21) and control the execution subsystem; The execution subsystem includes: Spraying side: First valve (17) for controlling the flow rate of inhibitor; booster device (18) for providing spraying pressure; inhibitor container (19) for storing gangue powder-water mixed inhibitor; delivery pipeline (16) for connecting each spraying component and delivering inhibitor; Nitrogen injection side: Rear spraying device (14) for spraying inhibitor; second valve (24) for controlling nitrogen flow rate; nitrogen storage chamber (25) for storing high-purity nitrogen; nitrogen injection pipeline (26) for transporting nitrogen to goaf (2).

7. The method for planning the coordinated remining of isolated coal pillar resource roadways and fire prevention and extinguishing as described in claim 4, characterized in that, The instructions used to respond to the decision control subsystem include: When the carbon monoxide concentration is continuously ≥50ppm, the rear spraying device (14) is activated. When the oxygen concentration is ≥18% or ethylene gas is detected, nitrogen injection is initiated in the goaf (2), with the goal of reducing the oxygen concentration to below 12%.

8. The method for planning the coordinated remining of isolated coal pillar resource roadways and fire prevention and extinguishing as described in claim 7, characterized in that, The decision control subsystem executes the ANFIS-TOPSIS hybrid algorithm to dynamically assess the spontaneous combustion risk of the goaf (2) and precisely control prevention and control measures, including the following steps: a. Multivariate data acquisition and preprocessing: Collect gas parameters of the goaf (2), construct a monitoring parameter vector and perform normalization processing; (1) The data acquisition cycle is 5s, and the expression is: ； In the formula, For data collection cycle; (2) The physical parameters for the risk of spontaneous combustion of coal in the goaf at any given time are: ； in, Calculated using pressure gradient: ； In the formula, Permeability coefficient, For observation distance, The cross-sectional area of ​​the tunnel. This refers to the air leakage rate. (3) Data normalization processing, performing normalization on the 7-dimensional input. Normalization to : ； In the formula, for exist Time of the first The normalized values ​​of the parameters for exist Time of the first The original monitoring values ​​of each parameter, for In historical data, the first The maximum value of each parameter. for In historical data, the first The minimum value of each parameter. The parameter index has a value range from 1 to 7; in, Concentration detection generates a discrete indicator for triggering: ； In the formula, for The ethylene concentration exceeding the limit indicator variable at time [time]. The detection limit is determined by the equipment. The ANFIS output is: ； In the formula, The input vector is the normalized form. The normalized temperature. The normalized pressure difference The normalized air leakage intensity, The transpose operator converts a row vector into a column vector. b. ANFIS Risk Modeling: Input the normalized parameter vector into the ANFIS model, and the output will be a risk level representing the spontaneous combustion risk. ; (1) Input / output definitions: enter: Output, risk level of spontaneous combustion: ; Define risk level : ； In the formula, Let t represent the risk of spontaneous combustion at time t. Risk level of spontaneous combustion; (2) Fuzzy membership settings; For each input Set three fuzzy sets: low, medium, and high, respectively. Using Gaussian membership functions: ； In the formula, Input variables Belongs to the Fuzzy set membership degree This corresponds to the center value of the Gaussian function. To correspond to the width of the Gaussian function, For fuzzy set index; (3) Rule layer and post-rule; No. Rule 1: ； In the formula, For the first A fuzzy rule, , For the normalized input variables, , For the first In this rule, the corresponding fuzzy set of input variables is represented by ∧, which stands for logical AND operation, indicating that all conditions must be true simultaneously. For the first The output function of the rule, For the first Rule number 1 The linear coefficients of the input variables, For the first The constant term of the rule; Rule trigger strength: ； In the formula, For the first The trigger strength of a fuzzy rule; Normalization: ； In the formula, For the first The normalized trigger strength of the rule, For the first The trigger strength of the rule; ANFIS output: ； In the formula, for The risk of spontaneous combustion at any given moment. For the first The consequent of the rule outputs the function value; (4) Training objectives; If there is a historical spontaneous combustion event A, provide the historical fire warning / response records. Minimize the mean square error: ； In the formula, Mean square error, The total number of training samples, For the first The true risk label of each sample For the first The model predicts the risk level for each sample; If there is no historical spontaneous combustion event B, construct pseudo-labels using thresholds, including ethylene veto and O2 / CO thresholds; ； In the formula, for False risk labels at all times for Excessive weighting coefficients for CO out-of-limit state variable at time t. This is the weighting coefficient for oxygen exceeding the limit. The weighting factor for ethylene exceeding the limit. for The indicator variable for ethylene concentration exceeding the limit at any given time; Pick If ethylene is detected, nitrogen injection is initiated. c. TOPSIS Strategy Selection: Based on Risk Level The weights of TOPSIS evaluation indicators are dynamically adjusted to select the optimal fire prevention and suppression strategy from the candidate strategy set. (1) Candidate strategy set : Only observe and issue warnings, without taking any action / or at extremely low intensity; Low-intensity spraying; inhibitor spray flow rate = 20 L / min, duration = 30 min; High-intensity spraying; inhibitor spray flow rate = 50 L / min, duration = 60 min; Low-intensity nitrogen injection; nitrogen injection flow rate = 200 m³ / h, duration = 60 min; High-intensity nitrogen injection to achieve an oxygen concentration of less than 12%; nitrogen injection flow rate = 500 m³ / h, duration = 120 min; Low-intensity spraying combined with nitrogen injection; High-intensity spraying combined with nitrogen injection; Each strategy is associated with adjustable parameters: ； In the formula, For the first The parameter vector of each candidate strategy For spraying intensity, For nitrogen injection flow rate, Duration; (2) Hard constraint clipping; like Then the candidate set must include spraying types. ; like or Then the candidate set must contain nitrogen injection type. ; For all candidate strategies involving nitrogen injection, the objective constraint must be satisfied; therefore, the following must be predicted or set: ； In the formula, This is a predicted value for oxygen concentration. For the current moment, This represents the expected execution time of the strategy. Otherwise, the strategy is deemed infeasible and eliminated; (3) TOPSIS indicator system; For each candidate strategy, construct an index vector. ,in, To achieve the ability to reduce oxygen levels to meet standards, CO inhibition ability, For the time to take effect, For material / energy costs, To mitigate production disruptions, To ensure safety and controllability, a decision matrix is ​​formed. Rows represent strategies, and columns represent metrics; (4) Quantitative indicators; The effect of nitrogen injection on oxygen: Let the effective influence volume be... Mixing efficiency : ； Define the oxygen reduction target indicators: ； In the formula, For strategy The oxygen reduction capacity indicator; The empirical model for the exponential decay of CO suppression by spraying is as follows: ； ； In the formula, This is a predicted value for carbon monoxide concentration. For the spraying of inhibitors Suppression efficiency coefficient For strategy CO inhibition capacity index; Onset time / cost / disruption / safety: ； ； ； ； In the formula, For strategy The onset time indicator. For strategy The expected onset time, For strategy Material / energy cost indicators This is the cost coefficient per unit amount of inhibitor sprayed. The cost coefficient per unit nitrogen injection volume For strategy Production disturbance indicators. The disturbance coefficient of spraying intensity on production. The disturbance factor of nitrogen injection flow rate on production. For strategy Safety and controllability indicators, The penalty coefficient for the safety risks associated with high concentrations of methane. To predict the penalty coefficient for safety risks caused by excessively low oxygen concentration, For high concentration methane threshold, This is the lower limit of safe oxygen concentration for the operation. (5) TOPSIS standard calculation; Positive indicator: ； In the formula, The positiveized index value, The first decision matrix is ​​the first decision matrix. The first strategy The original values ​​of each indicator For indexing indicators, The first of all strategies The maximum value of each indicator. The first of all strategies The minimum value of each indicator; Normalization: ； In the formula, These are the normalized index values; Weighted: ； In the formula, These are the elements of the weighted decision matrix. For the first Weighting coefficients for each indicator; Positive ideal solution / Negative ideal solution: ； In the formula, For the positive ideal solution, For a negative ideal solution, In the first The maximum value among all strategies for each metric. In the first The minimum value among all strategies for each metric; Distance and application progress: ； ； In the formula, For the first The Euclidean distance between each strategy and the positive ideal solution For the first The Euclidean distance between each strategy and the negative ideal solution. For the positive ideal solution in the th case The value of each indicator For the negative ideal solution in the th case The value of each indicator For the first The relative similarity of the strategies; Pick The strategy with the largest value is the optimal strategy. ； In the formula, for The optimal fire prevention and extinguishing strategy selected by the system at all times. For strategy indexing; (6) Dynamic regulation of ANFIS→TOPSIS; Using ANFIS risk level To dynamically adjust the TOPSIS weights, the remaining weights are supplemented using normalization; When approaching a danger zone, the system selects a combined and high-intensity strategy; ； ； In the formula, The weighting of the oxygen reduction target achievement indicator dynamically changes with the risk level R. The weights of the CO suppression capacity index are dynamically changed with the risk level R. The weights of material / energy cost indicators are dynamically adjusted according to the risk level R. The weights of the production disturbance index are dynamically changed with the risk level R. The spontaneous combustion risk level output by the ANFIS model; d. Instruction Mapping and Execution: Mapping the optimal strategy into specific control instructions and sending them to the execution subsystem; (1) Control output vector and send it to PLC ； In the formula, for Control command vectors sent to the PLC at all times for The required inhibitor spraying intensity as specified in the time instruction. for The nitrogen injection flow rate required by the time command. for The duration of the measures required by the time-of-day instruction. These correspond to the opening degrees of the first valve (17), the booster (18), the rear sprayer (14), and the second valve (24), respectively, with an opening range of 0-100%. (2) Mapping of optimal policy to action; like For low-level spraying, the first valve (17) is set to 30% opening, the booster equipment (18) is started, and the second valve (24) is closed for 30 minutes. ； In the formula, The optimal strategy selected by the system. For low-intensity spraying strategy, The execution duration specified in the instruction. For strategy Preset duration; like If nitrogen injection is low, that is, the first valve (17) is closed, the booster equipment (18) is stopped, and the second valve (24) is set to open at 40% for 60 minutes: ； In the formula, For low-intensity nitrogen injection strategy, The nitrogen injection flow rate specified in the instruction. For strategy Preset nitrogen injection flow rate, For strategy Preset duration; like Then, the high-intensity combination, that is, the first valve (17) is opened to 80%, the booster equipment (18) is started, the second valve (24) is opened to 90%, and the duration is 120 minutes: ； In the formula, For strategy Preset spray intensity, , for strategy Preset nitrogen injection flow rate, For strategy Preset duration; Other situations: ,valve closure; High spraying, that is, the opening of the first valve (17) is set to 80%, the booster equipment (18) is started, the second valve (24) is closed, and the duration is 60 minutes; High nitrogen injection, that is, the first valve (17) is closed, the booster equipment (18) is stopped, the second valve (24) is set to 90% opening, and the duration is 120 minutes; Low-intensity combination, that is, the first valve (17) is opened to 30%, the booster equipment (18) is started, the second valve (24) is opened to 40%, and the duration is 60 minutes; (3) Hard trigger forced set overwrite; Regardless of the TOPSIS output, execution is forced as long as the triggering condition is met: ； ； The nitrogen injection target is written as a closed-loop constraint, namely, the first valve (17) is fully opened, the booster equipment (18) is started, and the duration is 60 minutes: ； Complete dynamic control of fire prevention and extinguishing.

9. The method for coordinating remining of isolated coal pillar resource roadway systems with fire prevention and extinguishing as described in claim 1, characterized in that, In step S4, the windbreak wall is constructed of shale bricks and cement mortar. The side of the wall facing the goaf (2) is coated with a thick intumescent fireproof coating to achieve both fireproof and sealing properties. A drainage hole is reserved at the bottom of the wall to drain the water accumulated in the goaf (2). A monitoring hole is reserved in the middle to insert a gas detection device. The height is the same as the roadway, the width is 400mm wider than the roadway, and the thickness is ≥500mm. The main body of the windbreak curtain is made of 0.8mm thick flame-retardant canvas, and galvanized steel wire rope is used as the suspension load. Wide buttonholes are sewn around the canvas for threading steel wire ropes for fixing; an observation window is set in the middle for checking the condition of the goaf (2).

10. The method for planning the coordinated remining of isolated coal pillar resource roadways and fire prevention and extinguishing as described in claim 1, characterized in that, In step S5, step-by-step grouting is adopted. As the working face advances a certain distance, high-polymer solidified foam is injected into the side wall of the goaf (2) through a preset borehole to form an isolation wall. After grouting at that point is completed, the grouting pipe is withdrawn; the working face continues to advance, and when it advances to the next predetermined distance, the next isolation wall is constructed; this cycle is repeated until an isolation zone is formed.

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