Research On Gas Drainage Technology Of Long Hole In Zhongxing Mine Roof

With the mining depth and the increase of mining scale,the pressure of gas prevention and control in the mining face is getting larger and larger.The gas drainage in high pumping roadway is an effective treatment technology,but the high pumping lane has high construction cost and long cycle.Difficulties in later maintenance and tight integration of mining.Long-distance roofing of long-distance drilling,due to its flexible construction and high gas concentration,makes it possible to replace high-drainage.At present,the layout of the top plate to the long borehole is mostly based on field experience,the gas drainage efficiency is low,and the treatment effect is poor.Therefore,determining the optimal arrangement parameters and extraction parameters of the top plate to the long borehole has important guiding significance for controlling the gas in the working face.Based on the basic theory of fluid mechanics,this paper takes the Zhongxing Mine 1(02)09fully mechanized mining face as the engineering background,and proposes to use the top plate to drill long holes instead of high pumping alley to control the over-limit of gas in the upper corner.The FLUENT numerical calculation method is used to compare and analyze the feasibility of the long hole in the roof to replace the gas drainage in the goaf,and further study the horizon,spacing and pressure of the long hole in the roof to extract the gas and mix the gas.The influence of the scalar and upper gas angle gas concentration changes to determine the optimal extraction parameters for the long hole drilling of the roof.The optimization result is as follows:the optimal arrangement parameters for the long hole of the roof should be 15m from the bottom of the coal seam,and the horizontal spacing of the holes is 8m.On this basis,through analysis,it is found that simply increasing the negative pressure has a limited effect on improving the sifting volume of gas extraction,and at the same time,it is easy to cause serious air leakage in the goaf.It is determined by quantitative analysis that 13MPa?16MPa is the best pumping negative pressure.According to the optimized parameters,the top plate long-hole gas drainage technology is implemented in the 1(02)09 fully mechanized mining face.The on-site monitoring data shows that the highest single-hole gas extraction with this technology can reach 2.6m~3/min.The extraction mixing amount can reach up to 5.8m~3/min,the gas concentration in the upper corner is also reduced from 1.33% to 0.57%,and the gas concentration in the return air passage is reduced to 0.35%.It can be seen that the gas treatment effect is better after replacing the high pumping lane.This thesis has Figure 50,Table 20,and 60 references.