Effect Of Inert Gas Injection On Transport Law Of Gas In Closed Fire Zone

After fire breaks out in coal mine, it is common methods to seal fire zone and empty into fire zone with inert gas to prevent methane explosion. However, it may induce gas explosion. By employing the theoretical analysis, numerical simulation, laboratory testing, examples verification and some other means, the dissertation analyzes the sources and components of the combustible gases in the sealed fire zone, the formation of the gas layer and the migration laws of gas, and deduce the formula for calculating the concentration of combustible gases; the role of inert gas jet on the explosion suppression and the influence of inert gas jet on gas migration laws are studied. The critical wind speed formula to destroy the stability of the gas layer, the influence of inert gas jet on combustible gases' dilution effect and the piston driving effect, and the explosion condition of combustible gas induced by inert gas jet are determined; designed and carried out the simulation experiments of injection inert gas in the closed roadway. Through the analysis of experimental results, the correctness of theoretical analysis and the numerical simulation results is verified. Finally, a in-site of Fu-Hua mine is presented to analyze the concentration change process in the injection process of inert gas, and a reasonable amount of inert gas is calculated. The study results have great significance for preventing the occurrence of secondary disasters on the relief process of coal mine fire disaster.