Optimization Study On The Layout Of High Drainage Roadway For Prevention And Control Of Gas Overrun In The Corner Of 1301 Working Face Of Licun Coal Mine

With the continuous development of comprehensive mechanized coal mining technology,the working face mining intensity increasing,make a dramatic increase in working face of coal gas,but also make the adjacent layer coal unloading gas emission increased sharply,causing a lot of goaf,corner gas often overrun on the working plane,a serious threat to the safety production of working face.High alley pumping gas extraction technology is prevention of top corner gas overrun an effective technical means,the higher the location of the alley pumping parameters,arrangement,directly affects the effect of the gas extraction,due to high alley pumping large quantities,construction time,not in the field contrast test,with the application of numerical simulation technology,make some test that can not be completed at the scene,can be finished by the method of numerical simulation.High alley pumping arrangement has two kinds:towards high alley pumping and tend to smoke lane,two high drainage layout parameters(such as location,arrangement spacing and in-depth fissure zone length)of the gas extraction effect,high alley pumping are directly affect the quantity and time limit for a project,two high alley pumping the extraction effect of comparison and optimization,quantity and time limit for a project have very important sense to prevention and control of working face gas.In this paper,the 1301 working face of licun coal mine is taken as the research object.Firstly,the layout parameters(horizontal distance from the return air channel and vertical distance from the floor of the coal seam)of the high drawing roadway in the strike are optimized to obtain the optimal high drawing roadway in the strike.The optimum vertical height was extended to the inclined high drainage roadway after optimization,and the optimum layout parameters(length of deep fracture zone and spacing)of the inclined high drainage roadway were selected to obtain the optimal inclined high drainage roadway.Finally,under the condition of ensuring that the gas concentration in the corner of the working face is within the safe range,the optimum direction high drainage roadway and the optimum inclination high drainage roadway are optimized.By comparing the gas extraction effect,construction cost and working face preparation time of two different high drainage roadway layout modes,the actual high drainage roadway layout mode of 1301 working face is guided.Through theoretical analysis and numerical simulation,this paper mainly does the following work:(1)Optimum selection of high extraction roadway.The height range of the fracture zone is 27.3-49m and the horizontal distance from the return air lane is18.1m-51.3m.Initially,assuming that the distance between the high extraction roadway and the return air along the trough is 30 m,the gas concentration at the extraction mouth and the gas concentration at the upper corner of the high extraction roadway are simulated respectively when the distance between the high extraction roadway and the floor is 30 m,34m,38m and 42m.When the vertical distance is 38 m,the extraction effect is the best.Then,the effect of gas extraction is simulated when the horizontal distance between high extraction roadway and return air roadway is 20 m,30 m,40 m and 50 m respectively.When the distance is 30m from the return air lane,the gas concentration of high extraction Lane reaches 10.33%,and the gas concentration of upper corner is 0.752%.To sum up,the optimum location of high extraction roadway is 38m from floor and 30m from return air roadway.(2)Optimum selection of high suction roadway with the best inclination.The optimum height of high-inclined Roadway after optimization is applied to high-inclined roadway,and the different distances of high-inclined roadway in deep fissure zone are optimized.The best extraction effect is determined when the deep fissure zone is 30m.According to the specific layout location of high-inclined roadway,10 high-inclined roadways can be replaced by one high-inclined roadway under the same amount of engineering,and the simulation spacing is166m,144m,122m and 10m,respectively.Gas drainage effect in high-inclined roadway at 0 M.It is found that when the distance is 144m,the extraction purity is 30.75m3/min,and the gas concentration in the upper corner of the working face is within the safe range.Therefore,the reasonable distance of inclined high extraction roadway is 144m.(3)Optimum selection of high-drawing roadway with the best direction and the best inclination.Comparing the best direction high-extraction roadway and the best tendency high-extraction roadway,quantitatively analyzing different extraction parameters,the gas concentration in the upper corner of the two roadways is not the same,but the extraction purity of the inclined high-extraction roadway is obviously higher than that of the trend high-extraction roadway,the extraction purity per minute is increased by 8 m~3.Comparing the construction cost of the two methods,the economic expenditure can be saved by 43%by using the inclined high extraction roadway,and the preparation time of the working face can be shortened by 7 months by using the inclined high extraction roadway.Considering the extraction effect and economic cost,the 1301 working face of Licun Mine is more suitable for the layout of high-inclined roadways.