Research On Gas Drainage Effects Of High Level Drainage Roadway On The Strike And High Level Boreholes In Fullly Mechanized Mining Face

Gas disaster is one of the main problems that affect the safety production of coal mine.The extraction of gas can not only effectively reduce the amount of gas emission, prevent gas explosion and coal and gas outburst, but also the extracted gas can be used as a clean energy associated with coal to be used.With the increase of the depth of coal mining, the gas content and gas pressure in the coal seam is also increasing. The high concentration of gas affects the safe and efficient production of coal mine, the innovation of mining method also makes the gas concentration in the The upper corner of working face and return air lane often overrun. It seriously restricts the safety production of the mine and reduces the production efficiency of the mine. At the same time, there is a huge security hidden danger to the underground production personnel and the mining equipment.Therefore, to solve the goaf gas influx on the upper corner essentially is the key to improve the working face production efficiency and reduce production security threat.There are two main ways to avoid gas overrun in the high gas coal mine working face upper corner and return air lane,Reduce the gas concentration in the goaf, high pumping lane and high hole drilling.Firstly, this paper analyzes the characteristics,the source and composition of gas emission in the coal working face and the gas migration law in the goaf of Ma Lan coal mine, and found that the gas emission from goaf is still the main reason of gas emission in working face. It plays an important role that decrease gas emission in goaf to govern gas overrun in the working face upper corner and gas concentration of back flow.Based on the lithology characteristics of the overlying strata in the 8 # coal seam of Ma Lan coal mine, the height of caving zone and fracture zone, and the relative parameters of horizontal three zone are obtained through theoretical calculation and analysis.By using fluent numerical simulation of the high pumping lane and the high level borehole in the drainage effect of coal 8#, combined with the actual observation data, calculated pumping production rate,and obtained two extraction efficiency.In the end, the advantages and disadvantages of the high lane and the high hole drilling are analyzed, and the applicable conditions of the two different methods are put forward.