Abstract: The equal-equation equation of homogeneous turbulent combustion time, k?ε turbulence model and Ebu-Arrhenius combustion model in ANSYS Fluent software were used to simulate the explosion process of methane air premix gas in the gas bunker of integrated pipe gallery with built-in obstacles, and the influence of different fire source positions on the ignition process in the gas bunker of integrated pipe gallery with built-in obstacles was discussed. The results show that when the height of ignition source is lower than the level of obstacle in the vertical direction, the flame is disturbed the most and the flame propagates the slowest. In the horizontal direction, the smaller the distance between ignition source and obstacle, the slower the pressure rise rate.

Key words: underground utility tunnel, obstacles, combustion and explosion, ignition source