Research And Application Of Goaf Gas Control Technology In Fully-mechanized Working Face1011of Yuandian NO.1

With the increasing of coal mining intensity of Yuandian NO.1working face, the gas emission of working face goaf will also increase, as well as the gas concentration of the working face upper corner and ventilation roadway, which often cause a direct result of gas overrun, so it seriously threatens the safety of mine workers and normal mining working face. Therefore, in order to ensure the high performance of normal production, we should be taken the goaf gas control measures.Through theoretical analysis, FLUENT numerical simulation and on-site industrial validation method, goaf gas control techniques were studied and analyzed on the Yuandian NO.1mine1011fully-mechanized working face. First, we analyzed overburden failure rules for the mechanized mining goaf and the zone porosity and hulking coefficient porosity zones, and combined with field data to identify the damaged zone overlying strata division situations, caving zone area is0～13.04m, air conductivity region with a maximum height is33.58～44.78m; Then, we studied and analyzed the effect factors of goaf gas emission and the goaf gas emission calculation methods, and mastered Yuandian NO.1mine fully-mechanized coal face goaf gas emission situation, the gas emission of working face is25.28m3/min, emission of mined out area is14.86m3/min. Meanwhile, apply the theory of porous media fluid mechanics and goaf gas flow patterns to establish goaf gas flow mathematical model,and using the FLUENT software,carry on the simulation study of the flow field in the mined out area.This paper, being under No gas extraction (i.e.only U-ventilation), Drainage pipe (pipe depths of10m,35m,60m), as well as buried pipe and high drilling co-extraction such circumstancessimulates the Three dimensional gas flow state.And under several conditions the gas distribution of working face goaf were compared and analyzed, it was concluded that buried pipe and high drilling co-extraction measures can better reduce gas concentration in the goaf, goaf gas reducing flowing to the working area. Finally, through the scene of Yuandian NO.1mine fully-mechanized coal face goaf verification, inspection results through buried pipe and high drilling co-extraction, there are the conclusion:using buried pipe and high drilling co-extraction can be drained to a large number of gas, High drilling and pipe average drainage reached26.72%and7.29%respectively, and the upper corner and return airway concentrations were reduced to0.32%and0.27%, to solve the problem of gas overrun, played a good social and economicbenefits.