Disasters of gas-coal spontaneous combustion in goaf of steeply inclined extra-thick coal seams  

作　　者：Qiming Zhang Enyuan Wang Xiaojun Feng Shuxin Liu Dong Chen 

机构地区：[1]Key Laboratory of Gas and Fire Control for Coal Mines(China University of Mining and Technology),Ministry of Education,Xuzhou,221116,China [2]School of Safety Engineering,China University of Mining and Technology,Xuzhou,221116,China [3]Henan Shenhuo Coal&Power Co.,Ltd.,Yongcheng,476600,China [4]State Key Laboratory for Geomechanics&Deep Underground Engineering,China University of Mining and Technology,Xuzhou,221116,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2024年第10期4141-4153,共13页岩石力学与岩土工程学报（英文）

基　　金：support from the National Key R&D Program of China(Grant No.2022YFC3004704);the National Natural Science Foundation of China(Grant No.52374241);the National Natural Science Foundation of China Youth Foundation(Grant No.52104230).

摘　　要：In light of the escalating global energy imperatives,mining of challenging-to-access resources,such as steeply inclined extra-thick coal seams(SIEC),has emerged as one of the future trends within the domain of energy advancement.However,there is a risk of gas and coal spontaneous combustion coupling disasters(GCC)within the goaf of SIEC due to the complex goaf structure engendered by the unique mining methodologies of SIEC.To ensure that SIEC is mined safely and efficiently,this study conducts research on the GCC within the goaf of SIEC using field observation,theoretical analysis,and numerical modeling.The results demonstrate that the dip angle,the structural dimensions in terms of width-to-length ratio,and compressive strength of the overlying rock are the key factors contributing to the goaf instability of SIEC.The gangue was asymmetrically filled,primarily accumulating within the central and lower portions of the goaf,and the filling height increased proportionally with the advancing caving height,the expansion coefficient,and the thickness of the surrounding rock formation.The GCC occurs in the goaf of SIEC,with an air-return side range of 41 m and an air-intake side range of 14 m,at the intersection area of the“<”-shaped oxygen concentration distribution(coal spontaneous combustion)and the“>”-shaped gas concentration distribution(gas explosion).The optimal nitrogen flow rate is 1000 m3/h with an injection port situated 25 m away from the working face for the highest nitrogen diffusion efficacy and lowest risk of gas explosion,coal spontaneous combustion,and GCC.It has significant engineering applications for ensuring the safe mining of SIEC threatened by the GCC.

关 键 词：Steeply inclined extra-thick coal seams Gas explosion Coal spontaneous combustion Coupling disaster Numerical simulation 

分 类 号：TE311[石油与天然气工程—油气田开发工程]