Abstract:In order to optimize the gas treatment of high gas mines, this paper takes the S1205 working face of Yuwu Coal Industry as the research object, and uses numerical simulation methods to study the gas concentration distribution under four ventilation modes: U-shaped, W-type, U+ high-pumping type and Y-type. The research methods include the establishment of numerical models to determine the key parameters such as fragmentation coefficient, permeability and gas mass source phase of mining fractured coal and rock, and the simulation analysis is carried out by using FLUENT software. The simulation results show that the gas concentration in the upper corner exceeds 1% and 9.3% respectively under the U-shaped and W-shaped ventilation modes, which cannot meet the safety requirements. In contrast, the U+ high-pumping ventilation mode effectively reduces the gas concentration when the negative pressure of the high-pumping roadway is 8KPa, in which the gas concentration of the return air roadway is kept below 0.5%, and the gas concentration in the upper corner is reduced to less than 0.8%. Further analysis of the influence of the high extraction roadway layer on the gas treatment effect shows that when the high extraction roadway layer is between 15m and 20m, the gas concentration of the return air roadway can be better controlled. Although the Y-type ventilation method is theoretically better than the U+ high-pumping type, it is less economical.
