The Gas Drainage Technology Research In Fully Mechanized Coal Mining Face Of Sijia Zhuang Coal Mine

In recent years, with the integration of coal resources, the country increases the degree of attention to the coal mine safety production, and has issued a series of related laws, regulations and rules. So with the gradually increasing of coal production, coal mine accidents have declined year by year and the situation of safety production has been further improved. But the major serious accidents data in recent ten years show that the "gas" is still one of the main factors that threat miners’life and influence the high yield and high efficiency production. And with the increase of excavation depth, the gas emission increases, so bringing gas under control has become the most significant problem in most of mines especially the high-gas mines.The paper studies the gas migration characteristics in fully mechanized working face on the basis of analyzing the fluid motion form in porous media, and summarizes the different prevention and control measures on the basis of fully understanding the gas disasters. With the15108working face production conditions in Yangquang Sijia Zhuang Coal Mine, a high-gas mine, as the background, the paper studies and looks for the comprehensive and control measures to solve the gas problem respectively from two aspects of gas drainage and ventilation air methane.Analyzing the drilling coal samples obtains the gas pressure, the permeability coefficient of coal seam, the coal seam gas content etc., predicts the mine gas relative volume of21.31m3/t, the absolute gas emission content of197.29m3/min, so it is a high-gas mine, and estimates the mine gas reserves. And the paper studies the necessity and feasibility of gas drainage from the ventilation capability, gas emission status and other aspects. According to the gas emission situation, putting forward the comprehensive gas drainage method of working face drainage before mining, draining while mining and drainage adjacent layer gas with high pumping lane. After the actual drainage effect observation, the working face gas drainage volume is105.56m3/min, the extraction rate reaches more than80%, the gas drainage of high pumping lane remains at97m3/mm, the drainage concentration is37%, so the extraction effect is stable.Meanwhile, the working face arranges a cross end lane2.5meters above the coal seam roof, to form the "U+I" type ventilation system. Through the ventilation air methane effect analysis, we can see that the average gas drainage volume of cross end lane is11.43m3/min, the wind rate is42.1%, and the gas concentration in top corner of working face always overruns. Considering the cross end lane affected by roof caving, it failed to give full play to the role, so the paper uses the Fluent software to simulate the gas concentration distribution at different heights. The results show that increasing the height of cross end lane appropriately can solve the gas overrun problem effectively in top corner, and reduce the gas concentration in return air lane.The paper uses the gas drainage combined with ventilation air methane to manage the gas problem comprehensively in Sijia Zhuang coal mine. It not only improves the safety production environment, and the gas produced can be used as an important energy resource.