Abstract: For improving accident investigation and flame-proof technology application in coalmines, the gas explosion simulator-FLACS was used to model the full-scale longwall coalface and calculate the flame propagation, attenuations of shockwave overpressure and dynamic pressure on straight roadways, corners and bifurcations in a worst-case gas explosion based on the information from accident investigations. It was found that the free spaces provided by bifurcations limit the flame propagation obviously, that overpressure decays dramatically at corners and bifurcations, that the blast wind velocity just declines distinctly on bifurcations, and both corners and long straight roadway have little impact on it, and that the high-speed blast wind with debris and toxic smoke are the most important destructive factor at far field disaster areas. The quantitative results are helpful in percepting the full-scale gas explosion characteristics, rebuilding accident scenarios and optimizing flame-proof technology application.

Key words: gas explosion, flame propagation, overpressure, dynamic pressure, coalmine safety