1. CCTEG Shenyang Research Institute, Shenyang 110000, China
2. Key Laboratory of Gas and Fire Control for Coal Mines, School of Safety Engineering, China University of Mining and Technology, Xuzhou 221116, China
3. International Research Center for Underground Coal Gasification, China University of Mining and Technology, Xuzhou 221116, China
4. School of Safety Science and Engineeringj, Anhui University of Science and Technology, Huainan 232001, China