Temperature and Gas Pressure Features in the Temperature-control Blasting Underground Coal Gasification

Abstract

Abstract In this article, through model testing of the temperature-control blasting underground coal gasification, change features of temperature and gas pressure in the gasifier are studied. Measurement results show that in the process of the gasification of coal seams, with the passage of time, the dislodging effect of the coal seams from the thermal explosion gradually improves, the rate of the temperature rise quickens, and the temperature gradient of the coal seams media continuously lowers. According to measurement data, the average dropping rate of temperature gradient in the direction of slope for seams is 0.156°C/cm.h, and in the direction of thickness, 0.201°C/cm.h. Characteristics of zones in the gasification space are also pointed out. The experimental data indicate that, in a drop out zone, the change of fluid pressure is small; in a combustion zone, the gas pressure decreases sharply, with the pressure difference of 210–290 Pa; in the area dislodged by explosions, the gas pressure is relatively small, generally between 20 and 70 Pa.