Abstract: In this paper, an explosion roadway with the length of 100 m and cross-sectional area of 0.08 m×0.08 m was established by using AutoReaGas Software, where the methane/air mixture gas with 9.5% fuel concentration is distributed uniformly within the first 10 m of the roadway. The results show that the maximum explosion overpressure presents a changing trend of decreasing, increasing, and decreasing again in the process of gas explosion propagation, and reaches its maximum value near the location where the flame is extinguished. Both the maximum combustion rate and flame propagation speed increase firstly with the increase of propagation distance, and then begin to decrease after obtaining their corresponding maximum values. The maximum overpressure and gas velocity have reduced to zero at the distance of 35 m from the ignition source, and the maximum density also has decreased to its initial value at this distance. These trends indicate that the explosion-proof safety distance is 35 m under this condition. The maximum combustion rate and flame propagation speed have reduced to zero at the distance of 17 m, which indicates that the maximum distance of flame propagation is 17 m. The occurrence of gas backflow is related to flame propagation. The research results can provide references to optimal route determination for avoiding gas explosion disasters in underground coal mines, the emergency rescue and disaster relief after gas explosion, the explosion accident investigation, and so on.

Key words: gas explosion, blast wave, flame, explosion-proof safety distance, numerical simulation