Suppression effect of porous media on natural gas explosion in utility tunnels

The prevention and control of natural gas explosion accidents in utility tunnels have drawn great concern due to the unexpected severe consequence. In this study, put forward an explosion suppression measure apply to utility tunnels. An experimental platform for simulating the process of the natural gas explosion in utility tunnels is set up to study the flame propagation law and pressure dynamics distribution under the suppression effect of porous media. Seven experimental configurations of different pore density PPI (pores per inch) and thickness of the porous media are evaluated to investigate the influencing factors of explosion suppression efficiency. The results indicate that lining the sidewalls with porous media does have a certain explosion suppression effect. However, the quenching efficiency of media with small PPI is not significant, or even result in quenching failure, which may be related to flame acceleration due to the interaction between affiliated facilities and flame front. The PPI of porous media is kept constant, and the explosion suppression efficiency is pretty enhanced as the thickness of media increases. Besides, when selecting the suitable porous media as the explosion suppression materials, the acceleration effect of surface roughness on flame propagation cannot be ignored.