Study On Gas Drainage Technology Of High-position Tunnel In 9101 Working Face Of Wangzhuang Coal Mine

With the increase of mine exploitation intensity and the increase of mine exploitation depth, gas emission increases sharply in coal face are obtained, so the gas concentration in the air-return tunnel and upper corner always overrun, but goaf gas extraction of high-position tunnel can reduces gas concentration in goaf, and controls the gas concentration in the air-return tunnel and upper corner. Therefore, confirming the best extraction location, researching the gas distribution in goaf when the high-position tunnel stay in the the best extraction location, and analyzing the influence of subpressure on wind leakage in goaf, gas distribution in goaf and effect of gas extraction have important guiding significance for governing coal working face gas and goaf fire.In the thesis, according to the basic knowledge of computational fluid dynamics, we combine porosity distribution of goaf inbreak in 9101 working face, use Fluent software to analyze the extraction mixing amount, amount of extraction gas, concentration of extraction gas and gas concentration in upper corner when high-position tunnel stays in different positions. Combining theoretical calculation and the change law of amount of extraction gas, concentration of extraction gas and gas concentration in upper corner when high-position tunnel stays in different positions, we confirm the best extraction location of 9101 working face: the vertical distance that distances from goaf floor is 39 m, the horizontal distance that distances from air-return tunnel is 30 m. In addition, the gas extraction of high-position tunnel has important effect on gas distribution of return air side in front of goaf.On the basis of best extraction location, we simulate analyzing the influence of subpressure on wind leakage in goaf, gas distribution in goaf and effect of gas extraction. Results indicate that under the effect of high-position tunnel extraction subpressure, along the length direction of working face, the wind current of air-leakage flow from working face to goaf in most range of working face. With the increase of subpressure, the change of range that wind speed flow from working face to goaf is obvious, but the wind speed and capacity that leak into goaf become more and more large; the wind speed in the return air side in front of goaf increase obviously. Gas concentration in the return air side in front of goaf diminishes gradually, and the area in goaf distances from high-position tunnel more close, the gas concentration in goaf changes more obviously. The extraction mixing amount and the amount of extraction gas increase gradually, the concentration of extraction gas and the gas concentration in upper corner decreases gradually, but the decreasing trend of gas concentration in upper corner is not obvious.