Experimental analysis of suppression effects of crosswise arranged porous iron-nickel materials on the natural gas explosion in utility tunnels

Natural gas pipeline in utility tunnels has been leading to great concern because of potential hazards charac-terized by flammability and explosives, which could pose a grave threat to the safe operation of utility tunnels and even surrounding facilities. Therefore, revealing the dynamic process of natural gas explosion in utility tunnels is quite important for the consequence analysis and risk assessment, especially in such complex scenarios with various facilities. In this study, a kind of porous material with low cost (porous iron-nickel materials) was selected and crosswise arranged to investigate its explosion-proof effects on the natural gas explosion in utility tunnels. The results demonstrate that porous iron-nickel materials have obvious suppression effects on the gas explosion process. The maximum overpressure decreases from 0.3898 Mpa to 0.2778 Mpa and the maximum flame front velocity decreases from 66.67 m/s to 37.51 m/s. It is also found that the inhibition effect of porous materials on explosion overpressure and fame front velocity increase with the increase of the number of holes in porous materials. This study is helpful to consequence assessment and risk analysis of natural gas explosion accidents in utility tunnels.