In order to solve the problem of gas concentration exceeding the limit in the upper corner of the return air in 3306 working face of Wangpo Coal Mine, a large-diameter drilling (φ550 mm ) goaf drainage technology is adopted to cut off the gas supply in the goaf and change the air flow field near the upper corner, reduce the gas concentration in the upper corner, and form a set of large-diameter drilling hole forming technology. The results show that the gas volume fraction in the return air corner of 3306 working face is 0.08% ~ 0.49%, with an average of 0.29%. The volume fraction of gas return air flow is 0.06% ~ 0.37%, with an average of 0.22%, which effectively controls the problem of gas overrun in the return air corner.
杨 帅. 大直径钻孔治理上隅角瓦斯技术研究[J]. 煤炭与化工, 2026, 49(4): 120-123，160..
Yang Shuai. Research on gas control technology of upper corner by large diameter borehole. CCI, 2026, 49(4): 120-123，160..
