Experimental study on the explosion behaviors of premixed syngas-air mixtures in ducts

Abstract

Explosion characteristics of premixed syngas-air mixtures at room temperature and atmospheric pressure were experimentally reported when the explosion flame propagates in ducts with various heights (H) and lengths (L). The discussion was based on flame morphology and pressure dynamics. The ratio of L/H and the ratio of H2/CO had a significant effect on the explosion flame behaviors as the explosion occurred in ducts. The structure of the explosion flame changes more drastically, as both the L/H ratio is large. The ratio of L/H affected the flame tip dynamics after the flame reached the duct wall, and the time of flame reaching the duct walls is divinable. For a given duct height, the shorter the duct length is, the faster flame propagates, and the maximum flame tip speed was higher as the duct length was small. For a given duct length, flame tip dynamics showed a nearly same development tendency, but the shorter the duct height, the faster the flame propagated. The venting pressure affected the overpressure dynamics, and the venting pressure increased with the increase of the L/H ratio and the H2/CO. For a given duct height, the overpressure reached the maximum value almost at the same time, and the longer duct length resulted in the greater maximum overpressure. Finally, for a given duct length, the higher duct height caused the higher maximum overpressure.