Numerical Simulation of Spontaneous Oxidation Zone Distribution in Goaf under Gas Stereo Drainage

In order to reduce spontaneous combustion in goaf at high methane mine, spontaneous oxidation zone distribution in goaf under methane stereo drainage is numerically studied by Fluent software. For the actual case of 8403 working face in Yang-Quan, According to the combination of gas velocity and oxygen concentration distribution, the oxidation zone distribution of horizontal and vertical surfaces are determined. The results shows that the distribution of spontaneous oxidation zone is asymmetrically at horizontal surfaces, the width of spontaneous oxidation zone of inlet side is wider than outlet side; at the vertical surfaces, the spontaneous oxidation zone is below 20 meters. By the contrast of the numerical oxygen concentration and measured oxygen concentration, good agreement is obtained, which shows that the numerical results is reliable. The methane concentration distribution shows that inner tail-roadway can effectively reduce methane concentration at working face's upper corner, and high drainage roadway can reduce methane concentration in the whole goaf.