Gas Distribution Law during Repeated Mining Period of Small Kiln Damaged Area
In order to grasp the distribution and emission patterns of gas in the repeated mining coal seam,and solve the problems of local abnormal gas emission,accumulation,and gas exceeding limits during the repeated mining period,taking the remaining goaf(area)and coal pillar in the third mining area of 2#coal seam of Tenghui Coal Industry Co.,Ltd.as the research object,this paper studied the positional relationship between the working face and the goaf(area),and analyzed the stress variation and gas migration characteristics during the lower layer repeated period on the basis of gas basic parameter testing.This study shows that when the gas volume fraction in a confined space exceeds 28.4%,the gas pressure can reach as high as 0.045 MPa;when the empty roadway of the working face is exposed,the instantaneous gas flow speed can reach 440 m/s,and then rapidly decreases.
small kiln damaged arearepeated mininggas distribution lawstress change