Reasearch On Gas Drainage Technology Of Gob Area Of Wangyun Coal Mine

The gas hazard is one of the most serious hazards. Gas emission quantity is an important factor affecting coal mine production safety. In the past years, the top-dropping method of fully mechanized coal mining is broadly adopted in the coal industry. Fully mechanized mining has a high capacity of production, leading to a higher level of gas emission with larger range of fluctuation, and further causing a high level of gas concentration in the return airflow and at the upper-corner of working faces. All of these constitute the potential dangers long being existing in coal mines. To understand the gas emission quantity and the law of gas migration in fully-mechanized face has its great significance for improving the situation of China’s coal mine production safety.Wangyun Mine is a high-gas coal mine, in the paper, the basic situation of mine is analyzed. And through the existing gas parameters, the No.15coal seam gas emission quantity is predicted. The source of the gas is found out, gas emission of Gob proportion was identified in the gas emission of Mining Face. According to the laws and characteristics of gob gas migration during coal mining. Gob gas migration characteristics are analyzed, includingup floating, diffusion and aggregation; Application theory of overburden caving band formed in the vertical direction, the fault zone and bending sinking.Binding of Mining face150101, height of caving zone and fault is determined, finally the goaf gas migration physical model is determined.Using150101working face of Wangyun coal mine as the research objective,based on the theory of mechanized mining face gob gas flow field numerical simulation, using the gas migration mathematics model is established in the mechanized mining face. This thesis simulates the gas seepage distribution law of gob and cover rock in the three conditions of the only air leakage,the only extraction of the high level suction roadway and the only extraction of the gas tail road by using FLUENT.Analysing the results of numerical simulation and learning that only leakage case, back to the romantic gas concentration reached about5%, serious concentration of more than1%limit, so gob gas must be drained.Only high pumping roadway drainage conditions, upper corner and return airway gas concentrations below1%, Explanatory tail roadway drainage played a very good effect. But, the tail roadway gas concentrations up to about4%is still higher than the2.5%, also illustrates the Gas Emission big gob. Set up the high level suction roadway gas gauge does not solve the problem. When setting up the tail lane drainage, upper corner gas concentration is1%or less and lane tail wind back the gas concentration is about2%. Thus increasing the gas tail roadway drainage, reducing the face amount of gas emission, effective governance mechanized mining face gas gauge problem, ensuring the safe production of the working face.