Gas control technology of reverse-hole connected high-level suction roadway in high gas influx working face

The gas extraction of high extraction tunnel is an effective means to control the gas outflow from the high-gas comprehensive discharge working face, but with the increasing mining intensity of the working face after the intelligent transformation, the amount of gas outflow accumulating in the upper corner increases significantly, and it is difficult to solve the problem of gas accumulation in the upper corner effectively with the conventional high extraction lane. The article proposes the use of reverse hole connecting high pumping lane technology to manage the gas in the working face with high gas outflow. Based on the characteristics of the No.15 coal seam of Changshun Coal Industry in Yangquan Mining Area, a numerical model is established, and the pumping characteristics of the reverse hole connecting high pumping lane are studied and determined, which is compared with that of the conventional high pumping lane, and the leakage law of the mining air space and the gas transport law of the working face are analyzed, and the influence of the connecting drill hole on the management of the gas is clarified. At the same time, a field test was carried out in 15101 general-purpose working face. The results of the study show that: by increasing the negative pressure of pumping, the conventional gas control technology for the high extraction tunnel can strengthen the effect of gas control, reduce the gas volume fraction in the upper corner from 4.68% to 0.94%, and form a “concave” shaped gas volume fraction zone inside the mining hollow area, but this technology cannot completely solve the problem of the upper corner; the use of the reversed borehole linking After adopting the gas control technology of the high extraction lane, the gas extraction effect is obviously strengthened, the gas volume fraction in the upper corner is significantly reduced, the gas volume fraction rapid growth area in the working face is reduced from 164−200 m to 192−200 m, the gas volume fraction rise area in the return wind side of the extraction zone is increased from 0−100 m to 0−130 m, and the maximum value of the gas volume fraction in the upper corner is reduced from 0.980% to 0.441%; Reverse Hole Connection Reverse hole connection can realize full-cycle gas extraction on the return side of the working face, not only pre-extraction of local coal seam gas before mining, but also diversion of the return corner during mining, and short-term extraction of the empty area after mining. The results of field test show that after adopting the gas management technology of reversed-hole connecting high pumping lane, the gas volume fraction of the working face is reduced obviously and the effect is stable, and the average values of the daily maximum volume fraction of the methane sensor T₀ in the upper corner and the methane sensor T₂ in the return-air lane are reduced from 0.70% and 0.51% to 0.20% and 0.33%, respectively, with the reduction rate of 71.43% and 35.29%; and the pure volume of pumping in the high pumping lane increased from an average of 26.81 m³/min to 29.86 m³/min, an increase of 11.38%.