关键词: 自燃煤层, 三带划分, 氧化升温, 氧浓度指标, 防灭火

Abstract: Aiming at the phenomenon of fire caused by oxidation and heating of residual coal in goaf, In this paper, The field measurement method is used to study the characteristics of O2, CO, CH4 concentrations and temperature changes in the goaf, Combined with the oxidation and temperature rise characteristics of residual coal, the ignition trend of goaf is predicted. The results show that: When the working face advances more than 80m, The coal body has been fully compacted, The reduction of oxygen concentration restricts the oxidation and heating reaction of residual coal, The goaf enters the asphyxiation zone and the CO concentration is stable at 18ppm; CH4 concentration showed a continuous growth trend with the advancing distance and gradually stabilized after a slight decrease. It decreases longitudinally from the middle of the working face to the roadway on both sides, and the maximum CH4 concentration is 1.15%; The peak temperature of each measuring point in the goaf lags behind. The peak temperature of the measuring point in the middle of the working face occurs earlier than the return air roadway and earlier than the inlet air roadway, and the maximum temperature does not exceed 21.2 ℃; The oxygen concentration index method is used to determine that the oxidation temperature rise zone is 42.8m, The minimum safe advancing speed of the working face is 0.658m/d, and there will be no spontaneous combustion of residual coal during mining. The relevant research has reference significance for the fire prevention and extinguishing design of similar working faces.