Research On The Spontaneous Combustion Hazard In Goaf Of DaShuitou Coal Mine’s Fully Mechanized Top Coal Caving Face

This study is based on coal seam easily spontaneous combustion and highly gas features of east 108 fully mechanized top-coal caving face, comprehensive utilization of technological means, such as goaf area measured in site and coal spontaneous combustion measured in Lab, and supplemented by computer numerical simulation and theoretical analysis method, studying on spontaneous combustion of “three- zone” in goaf and its scope change, evaluating danger zone in goaf and mined-out area of coal spontaneous combustion and gas coupling research, to provide the basis for treating fire hazard in goaf. First, we establishing monitoring system and temperature sensor in goaf of east 108 fully mechanized top-coal caving face, getting the change rule of the gas temperature and other indicators. Using least squares fitting function features and the theory of spontaneous combustion of “three- zone” to define the scope of the mine spontaneous combustion "three zones" division method. It is concluded that the down-corner angle oxidation zone width is greater than the width of the oxidation zone in upper corner, and the width of the oxidation zone associated with the degree of working face advancing, propulsion, the greater the oxidation zone width is smaller. Under the condition of normal production of mine, the cooled zone width is 46 m, width of oxidation zone is 17 m, behind the working face 63 m after suffocative zone. Second, the coal spontaneous combustion in goaf calculated by using Flue nt software to simulate, based on the oxygen concentration index to determine the scope of goaf spontaneous combustion "three zones", and analyzes the different leakage air volume influence on spontaneous combustion "three zones" range. Finally, east of 108 fully mechanized top-coal caving face goaf spontaneous combustion risk existing in the region and goaf gas explosion hazard, defines the goaf gas mixed with oxygen within reach explosion danger of coupling region, and does the east 108 working face goaf coupling zone judgment, the results showed that: coupling zone is located in the goaf in the oxidation zone in upper corner, and if the mine goaf coal spontaneous combustion, the coupling zone to have the risk of gas explosion.