Study on Extinguishing Limits of Liquid Fuel Flames in Confined Spaces

Abstract

To sustain a flame following fuel ignition, it must receive oxygen from the surroundings at a concentration above a stoichiometrically-determined threshold; otherwise, the flame will decrease in intensity or extinguish. These thresholds vary depending on the type of fuel. Using the aforementioned factors, it is possible to predict and control the characteristics of flames in confined spaces. While the combustion characteristics of flames exposed to the atmosphere have been actively studied under controlled conditions, it is more challenging to predict and remediate the impact of variables, which manifest in real fire sites. In this study, following the ignition of a flame in a confined space with limited oxygen supply, oxygen and carbon dioxide levels and temperature at this space were measured according to changes in the fuel supply capacity. The extinguishing limit oxygen concentration as well as the extinguishing time decreased in relation to the size of the initial source. These results can guide the design and control of fire-fighting equipment for the early detection and extinguishing of fires.