Abstract: In view of methane overrun with U type ventilation, Partial W type ventilation system is put forward. Gas emission law is studied by numerical simulation. Working face parameter is optimized to improve extraction rate as much as possible on the premise of mining safety. Research results show that gas concentration of working face, return current and upper corner drop sharply and methane overrun problem with U type ventilation is solved effectively; when coal pillar is 15 m wide, it will be stable in the course of drifting and mining. Field application of above findings ensures safety and high efficiency mining. The ventilation system provides a new method to realize the safe and efficient mining of high gas longwall mining with sublevel caving.

Key words: longwall mining with sublevel caving, partial W type ventilation system, numerical simulation, coal pillar width