Estimation of the Fireball Size in an Ethyne–Air Cloud Explosion

Abstract

A gas explosion accident is often followed by a serious fire. In order to effectively prevent fire induced by a gas explosion accident, it is necessary to have some knowledge of the related explosion processes. The subject of the present study is to examine deflagration behaviors beyond the original cloud of the ethyne–air mixture and the fireball size in an ethyne–air explosion by means of numerical simulations. The explosion overpressure, flow velocity, and reaction rate distribution in an ethyne–air explosion are obtained. The peak explosion overpressure is found to reach its maximum beyond the original cloud for ethyne–air mixtures with ethyne concentrations greater than 13% (by volume). The explosion pressures beyond the original cloud may be higher than those within the cloud for these ethyne–air mixtures. The ratio of the combustion range to that of the original cloud is 1.4–2.7 in the radial direction on the ground and 1.5–4.0 along the axis of symmetry perpendicular to the ground.