Study On Gas Drainage Technology Of High Extraction Roadway In Xiagou Coal Mine

In the thick coal seam,the gas emission in the fully mechanized caving face is large,mainly from the goaf.It is easy to cause gas overflow at the upper corner during the advancing of the working face.Gas drainage technology of high extraction roadway on roof is an effective method to control gas in goaf.In this thesis,the ZF301 working face in Xiagou Coal Mine is taken as an engineering example,the reasonable position and drainage negative pressure of high extraction roadway and air supply rate in the working face are studied.In this thesis,the gas emission quantity of ZF301 working face is predicted and analyzed according to the gas basic parameters,the result shows,61 percent of the gas in the working face comes from goaf,and then the comprehensive gas control scheme which takes the goaf drainage as the main and the coal seam pre drainage as auxiliary is determined.According to the mining failure law of overlying strata,through the calculation to determine the ZF301 working face of the caving zone height 13.72?18.12m,the fracture zone height 47.03?58.23m.Based on FLUENT numerical simulation software,according to the gas seepage is established based on the theory of fully mechanized caving goaf gas seepage mathematical model,based on the caving O-ring model in goaf,and simulate the ZF301 working face roadway gas drainage effect in different locations,and different negative pressure drainage for the working face when the air volume.The results show that when the high pumping Lane from the wind Lane from the flat for the gas control effect of 20m,apart from the coal seam offset 25m the best,reasonable pumping vacuum extraction for 20kPa production,with the reasonable intake pumping speed is 2.5m/s.the work supply volume should not exceed 2475m3/min.Through the engineering application of high extraction roadway in ZF301 working face under the optimum parameters,analyzed the gas emission law of working face,and the gas extraction effect of high extraction roadway is investigated.Field data show that the roof of the ZF301 face is high,the average gas extraction rate of the roadway is 43.93/min,the maximum can reach 54.75m3/min,about 75.6%of the total gas emission,and the pumping effect is remarkable.The research results of this thesis can provide guidance for the gas extraction technology in the high suction roadway of the fully mechanized top coal caving face with similar conditions in the ditch coal mine and the adjacent mine.