Research And Application On The Gas Drainage System Optimization In Qianjiaying Mine

With our country’s increasing attention and investment to the coal mine safety work, the coal mine accidents are on the decrease each year. The decreasing of coal mine accidents not only effectively guarantees the life safety of the workers and increases enterprise production benefits, but also maintains a positive image for our government and country. However, the situation of preventing and controlling the coal mine accidents is severe at present, the coal mine accidents happen occasionally. Gas explosions in coal mines have a high ratio in production accidents, and prevention of gas disasters is a priority in the safe production of coal mines. To solve the problems of gas emission quantity in a deep level and local gas transfinite in Qian jiaying coal mine, the work of parameter determination of coal mining was conducted and the optimizing measures of the present gas drainage system was studied.Firstly, by introducing the development of gas drainage at home and abroad, it summarized the purpose and meaning of gas drainage. Secondly, it analyzed the vital role of gas drainage in solving the coal mine gas problems and the main problems existing in gas drainage in our c ountry. Thirdly, it introduced process principle of the second hole sealing method, which provides technical support for optimizing gas hole sealing in Qian jiaying mine.It conducted gas extraction experiments at depth of 600 meters in 2875 working face and heading face of the mine, meanwhile, it collected gas drainage indexes to find problems existing in gas drainage system. It carried out underground measuring of gas pressure in 5 and 7 coal-seams at depth of 850 meters, permeability index and drilling attenuation coefficient. By combining the method of decreasing the underground gas pressure and the numerical simulation of RFP A2D-Gas Flow, it measured that the reasonable drill-hole extracting space of 7 coal-seams is 2.6meter.On the basis of the measured extraction parameters, it changed parallel drilling along coal seam to integrated interchange drilling, and strengthened the processing of goafs. It used roof high-level boreholes to extract gas goafs, and improved techniques of drainage, drilling and hole sealing. In order to better the quality of hole-sealing, it applied second-hole sealing techniques. After the optimizing measures were used, the collected data showed that the gas drainage quantities were higher over 60 percent, and the concentration of mine gas was lowered obviously. The optimizing measures used in gas drainage system of Qian jiaying mine has solved the problems of local gas exceeding the limit and ensured the safety in production.