Methane- and propane-induced explosions in vented enclosures

Explosions in enclosures used to occur in various technological applications, leading to devastating accidents. Specifically, methane- and propane explosions are most typical to encounter in industrial and building enclosures. To relief the effect of such explosions, vents can be designed for the enclosures. In this particular study, an in-house computational model for gas explosion venting, developed by Ugarte et al [Process Safety and Environmental Protection, 99, (2016) 167-174] and validated on hydrogen-air fuel, is extended to analyze vented explosion scenarios for methane and propane. The physics of the gas explosion from the venting is govern by mass, momentum, energy and species continuity equations in three-dimensional space and time. While the solution of three-dimensional equations with the conventional computational fluid dynamics (CFD) codes is too expensive in terms of computational time and power, herein the governing equations in the three-dimensional space are reduced to a zero-dimensional (only time-dependent) set of ordinary differential equations. It is shown how the explosion effect depends on the equivalence ratio of the utilized fuels. The results show that the relief effect of the vent on the impact of the explosion is different for methane and propane. This is an important finding for the safety regulations.