Influences of multi vents’ numbers and distributions on vented ethanol-gasoline vapor deflagrations

Abstract

The safety issues and existing risks of ethanol-gasoline in industrial production have to be well considered and investigated. Especially when there are more than one thin doors, windows/thin walls in containers were broken once deflagrations occurred, but it appears that few researches deal with multi vented deflagrations. Hence we carried out experiments in a small cuboid container to investigate the effect of multiple vents’ numbers and distributions on vented ethanol-gasoline vapor deflagrations characteristics. Multi overpressure peak structures during multi-vented deflagrations were first observed and analyzed to reveal the complex physical process in the venting. Results show that five overpressure peaks’ structures were found (Pb, Pfv, Pcv, Pext and Pac) when multiple vents with the same area are arranged along the axis of the container’s roof. Flame propagation and overpressure buildup are mainly influenced by the 1st vent (i.e., the nearest one to the spark plug). The 1st vent also determines the number and types of overpressure peak structures. Compared with the single vent, the cases of multiple vents with the constant total vent area may cause larger Pmax, dP/dtmax and KG even if all vents are closer to the spark plug. Consequently, the use of multiple vents does not necessarily help to improve the vent effects.