Hazardous areas determination of coal spontaneous combustion in shallow-buried gobs of coal seam group: a physical simulation experimental study

摘要

The hazardous areas determination of coal spontaneous combustion plays a vital role in preventing and controlling the coal fire disaster. In this paper, a physical simulation experimental platform involving working face and ground surface air leakage was constructed to study the effects of ventilation rate and air leakage rate on spatial distribution of oxygen concentration in shallow-buried gobs of coal seam group. In addition, based on determined criteria of oxygen concentration, hazardous areas of coal spontaneous combustion were ascertained. Furthermore, the maximum width of hazardous areas was compared and analyzed. The results manifest that hazardous areas of coal spontaneous combustion is the result of the combined action of working face and ground surface air leakage, presenting a coupling form of S-shaped trend and a quarter inverted-cone caused by the working face and ground surface air leakage, respectively. Hazardous areas determination of coal spontaneous combustion using a physical simulation experimental platform can provide experimental foundation and theoretical basis for coal fire preventing and extinguishing in shallow-buried gobs of coal seam group.