| In coal mine gas drainage methods, long horizontal borehole gas drainage can not only improve the drainage volume and pumping efficiency but also reduce the cost of gas drainage, the bedding long borehole gas drainage technology is the development direction. But there are many difficulties in long borehole drilling, and not yet make full use of its to solve the issue of coal mine gas. Now, solve the long-hole bedding construction issues need to be addressed urgently as a major technical problems.Thesis get the traditional gas drainage method mainly to experience , the depth and space of borehole is not reasonable basis, he depth and space of borehole is big or small, cause blank belt and repeat cross, pumping efficiency is low, the cost of gas drainage is high , meanwhile restrict the safe production, by means of analyzes the gas drainage and long borehole development situation. Thesis combine the actual conditions of 1201 working face in Wuhu shan mine. First raised suitable layout method of 1201 working space is tendency and bedding borehole, At the same time, based on mine gas occurrence condition, gas content, gas diffusion movement and penetration movement in coal, get 1201 working space make use of gas desorption in underground, and established hundred meters borehole gas emission equation. According to the emission of gas calculate gas attenuation coefficients. Secondly, by forecasting of gas emission in 1201 working face, explains necessity and feasibility about gas drainage, meanwhile, determine borehole drainage time, the hole diameter, drilling Angle and negative pressure drainage according to analysis and calculation in 1201 working face return roadway. For laid foundation of rational arrangement borehole, improve drainage rate.Thesis research discharging pressure brought in return roadway coal wall make use of establish the limit equilibrium equations according to limit equilibrium theory, determine reasonable the depth of borehole; Ensure the gas drainage radius about drainage borehole make use of relative gas pressure method combined with field data, thus optimized for the space of borehole in 1201 working face return roadway,drainage rate increased to 33% from 17% . In addition the use of ANSYS finite element software for Wuhu shan mine 1201working face is gas drainage the numerical simulation to verity the result of the analysis and calculation.The method, by optimizing the gas drainage parameters, to improve mine gas drainage rate to reduce the mine's gas content, gas pressure so as to reduce the gas accident rate to a minimum and to ensure the safety mine production, has great practical significance in guiding the mine gas drainage work. It is proved that optimization method proposed in this paper, which can slove the real problem on-site practice, is reasonable, reliablel. |
