Experimental Investigation and Numerical Computation of Methane Combustion and Explosion Suppressed by Vapor

An experiment on methane combustion and explosion suppressed by vapor was conducted in an explosion shock tube, and corresponding numerical computations were made. The result indicates that the combustion velocity and explosion intensity of methane-oxygen mixture will decrease if a certain amount of vapor is added into the tube. When the amount of the vapor reaches critical value, the methane-oxygen mixture can not be ignited any more. Meanwhile, the chemical kinetics computational results indicate that the ignition delay time of methane is elongated, the combustion temperature is reduced and the concentrations of the free radicals of H, O and OH are reduced when the vapor is added in the mixture of methane-oxygen. It is concluded that the vapor can effectively restrain the combustion and explosion of methane, which owes to the combined effect of physical suppression and chemical inhibition.