Temperature-control Blasting Underground Coal Gasification in the Inclined Coal Seams with a Short Wall

Abstract

The temperature-control blasting seepage combustion technique in underground coal gasification is suggested in this article. The patterns of variation and interrelationship for the temperature-control characteristic parameters are studied. According to the test data, in the process of the gasification of the coal seams, with the prolonging of time, the interval for the thermal explosion of blasting caps gradually shortens, and the moving velocity of flame working face increases in a stepwise way. Research indicates that, in spite of the short wall of the coal seams used in the test, which influences the combustible gases contents, the dislodging effect of the thermal explosion still improves the H₂, CO, and CH₄ contents in the product gas, heating value of the gas, as well as the reducing rate. The experimental research shows that the dislodging effect from temperature-control blasting improves the permeability of the coal seam and provides a large reaction-specific surface necessary to the effective combustion gasification between gas and solid carbon, thus forming the gasification conditions of the seepage combustion in underground coal gasification.

Keywords:

• characteristic parameters
• flame working face
• seepage combustion
• temperature-control blasting
• thermal explosion
• underground coal gasification

Notes

^a Experiment time is November 2006.