Disturbance effects of oxidative zone induced by roof roadway drainage in gob

Gas drainage in roof roadway is a common method of gas drainage in goaf, and it is effective to control the gas at working face while induces the occurrence of coal spontaneous combustion in goaf.In order to analyze the disturbance effect of roof roadway drainage quantity on the distribution of oxidation zone, according to the engineering condition of 13190 working face in Gengcun mine, Yima, China, a physical model is established to study the air leakage flow field and oxygen concentration field in the goaf.Combining with field data, based on the validation of simulation in reliability, taking the air leakage amount in working face, the width, depth and area of oxidation zone in mined-out area as indexes, the disturbance effect of roof roadway drainage quantity on coal oxidation in goaf is discussed.The results show that:① with the increase of roof roadway drainage amount, the air leakage amount and area of working face increases gradually;② the increase of drainage quantity makes the boundary of oxidation zone to move to deep, the oxidation zone width and area increase gradually;③ In view of the specific disturbance effect of roof roadway drainage quantity, it should be set a reasonable roof roadway drainage quantity, in order to achieve the coordination of gas and coal spontaneous combustion disaster prevention.