Numerical Simulation on Goaf Gas Drainage of High-level Borehole in Pingshan Coal Mine

In order to solve the problem of high gas concentration in goaf and gas exceeding the limit in the upper corner at 11011 working face of 3^# coal seam in Pingshan Coal Mine, the goaf gas drainage of high-level borehole was proposed. On the basis of the design parameter equations of high-level borehole in goaf, this paper analyzed the gas drainage problem of goaf at 11011 working face of 3^# coal seam in Pingshan Coal Mine. Then, we used the Fluent to simulate the gas concentration distribution in goaf of high-level borehole, which displayed the distribution change of gas concentration. The high-level borehole was arranged in the outside “U” of the double “U”, the horizontal distance between the hole position and return airway was 20 m and the height of the hole was 4 m. The on-site experimental data showed that gas concentration of upper corner was less than 0.5%.