Prevention and cure mechanism of coal and gas outburst by injecting heat into coal seam

The ultimate purpose for preventing coal and gas outburst is pressure relief and reducing gas. Based on this standpoint, an in-depth study of the mechanical mechanism of prevention and cure mechanism of coal and gas outburst by injecting heat into coal seam was performed through theoretic analysis, numerical simulation and experiment. According the study on the action mechanism, the laws of temperature field, in-situ rock stress field and permeability changing after injecting heat into coal seam were found. The results show a few conclusions: After injecting high temperature water vapor into coal seam, the heat diffuses to large area with soaking. Thermal fracture will appear on the coal and rock due to heat transfer, the in-situ rock stress set free and the pressure relief is completed. A mass of gas desorption is released along the route way with thermal fracture on the solid frame as the expansion and activity of gas absorbing heat. Considering high stress condition, the effect of desorption and thermal fracture is more obvious, so the method is also applicable for deep mining. The prevention and cure mechanism of coal and gas outburst by injecting heat into coal seam are controlled by the pressure relief and gas desorption. It is an effective instrumentality for the prevention and cure of coal and gas outburst by injecting heat into coal seam.