Study on Regional Distribution of Spontaneous Combustion in Goaf of Deep Inclined Working Face and Effect of Low Temperature Inert Gas Injection

Abstract

ABSTRACT Affected by the occurrence conditions, the inclination angle of the goaf and the ground temperature change the caving structure and temperature rise environment of the goaf, which in turn affects the distribution range of the spontaneous combustion zone in the goaf. During the process of inert gas injection, the cooling and diffusion range of the inert gas determines the its inerting effect. In this paper, the temperature-programmed experiment was used to obtain the oxygen consumption rate of coal at different temperatures. Fluent simulation showed that when no inert gas was injected, the scope of the spontaneous combustion zone on the inlet side moved backward and expanded, while the gas in the gob on the return air side overflowed, and the spontaneous combustion zone The range becomes smaller; when inert gas is injected at low temperature, the influence of different inert gases (N2, CO2) on cooling and diffusion distribution is quite different, CO2 accumulates at the bottom of the goaf, and the influence range is larger; And the space inerting effect is better; the spontaneous combustion area is affected by the injection of inert gas, and there is a risk of secondary re-ignition when the inert gas injection ends.