"Three Zones" Division of Spontaneous Combustion in Goaf of Y-type Ventilation Fully Mechanized Mining Face

Abstract

The goaf of coal mine is accompanied by residual coal, and the possibility of spontaneous combustion determines whether the mine can work safely. Therefore, the division of "three zones" of spontaneous combustion in goaf under different working conditions is of great significance. This paper takes the 3154 fully mechanized coal face of Longmen Xianan Coal Mine as the research background to explore the "three belts" distribution under the Y-type ventilation mode. Based on the laboratory measured coal related spontaneous combustion characteristic parameters, the division standard of "three zones" is determined. Combined with the daily monitoring of the temperature and gas collection devices deployed on the site and the numerical simulation of the wind speed in the goaf, the comprehensive division of "three zones" in the goaf is realized. The results show that the range of "three zones" divided by temperature is similar to the range of oxygen concentration. The average width of heat dissipation zone and oxidation zone in the transport lane is 34.7m and 48.8m respectively. The asphyxiation zone is located at an average distance of more than 83.4m from the working face; The average width of the heat dissipation zone of the return air lane is 30.6m, the average width of the oxidation zone is 42.7m, and the average distance from the working face is more than 73.3m. In the numerical simulation, the width of the heat dissipation zone of the transport roadway is 35.0m, the width of the oxidation zone is 50m, and the asphyxiation zone is more than 85m from the working face. The width of the heat dissipation zone of the return air lane is 30m, the width of the oxidation zone is 40m, and the asphyxiation zone is more than 75m from the working face. The simulation results are close to the measured range of "three zones" of spontaneous combustion, and the width of "three zones" of return air roadway with Y-type ventilation is obviously different from that of transport roadway.