Study On Fire Prevention And Extinguishing Technology Of Close Distance Coal Seam Group Under The Influence Of Gas Drainage In Shanmushu Mine

The prevention and extinguishment of short distance coal seam group under the influence of gas drainage is one of the difficulties in coal mine fire prevention and control.Mine gas extraction and internal fire prevention and control is a pair of contradictory entia.Gas prevention and control requires "pumping out" the gas in the goaf and adjacent layer,while the internal cause of fire prevention is required to minimize the air leakage in the goaf.The two are contradictory and not easy to balance.This thesis take Shanmushu Coal Mine as the case,based on the principle of "prevention priority and economic harnessing".First,the experiment of heating up the main coal seam is used to set up the spontaneous combustion index system,so as to effectively advance the early warning of spontaneous combustion.Secondly,taking FTA to analysis the working face of the typical mine conditions of the Shanmushu Coal Mine that is based on the three stages of the initial mining stage,the over fault period and the final mining stage,the assessment of the importance of spontaneous combustion hazard is carried out to guide the fire prevention work in order and high efficiency and economic launch.The existing spontaneous combustion “three-zone” method is based on oxygen volume fraction is modified under the environment of nitrogen injection and high gas goaf,and the oxidation loss is put forward,and the spontaneous combustion “three-zone” is divided based on this value,the minimum thickness of spontaneous combustion oxidation and the minimum speed of working face are combined with this value to determine the dangerous zone of spontaneous combustion in the goaf.Based on the unique position relationship between the high pumping tunnel and the deep mining area in the working face,“the nitrogen injection disturbance coefficient” of the high pumping tunnel is proposed according to the quality conservation law.According to this coefficient,the nitrogen injection strength of the goaf is evaluated,and the gas extraction strength and nitrogen injection intensity are adjusted in a timely manner.Finally,according to the regularity index system of Shanmushu Coal Mine,Combined with the result of the accident tree analysis and the determination of the danger zone of spontaneous combustion in the goaf,makes use of the index system to advance warning,and prevents and controls the spontaneous combustion of the determined spontaneous combustion zone,and taking the "feedback compensation nitrogen injection process" and the high position drilling grouting(glue)as the core fire prevention and extinguishing means,and eliminate the dangerous source in turn according to their risk degree,the system of comprehensive fire prevention and extinguishing of close range coal seam group under the influence of gas extraction of Shanmushu Coal Mine is summed up,which provides a strong support for the fire prevention and extinguishing work of the Shanmushu Coal Mine.