Abstract: The underground utility tunnel has been widely used. In the pipeline leakage accident, the explosive load can cause serious damage to the utility tunnel structure. Aiming at reducing the threat of gas explosion in the utility tunnel, the porous structure barrier property of the underground utility tunnel with explosion process of methane/air premixed gas is simulated and analyzed by Fluent software. The effects of porous structure with porosity of 40%, 50% and 60% on explosion propagation, temperature reduction, explosion overpressure attenuation was studied. Based on the evaluation indicator, the paper comprehensively evaluated the barrier effect of porous structure on explosion in points of explosion over pressure and flame temperature. The results show that the porous structure shows good explosion suppression when the explosion suppression mechanism of the porous structure more than 58.4% is dominated, and there is a linear relationship between the internal porosity of the porous structure and the explosion suppression effect, the larger the porosity of the built-in porous structure is, the more significant the explosion suppression effect is. The maximum temperature can be reduced by 8%, the maximum overpressure can be attenuated by 38% , and the maximum velocity can be decreased by 33% .

Key words: gas tank, explosion, porous structure, porosity, barrier property