Flame extension for pool fires under ceiling at various heights

Abstract

Spill and ignition of flammable fuel can occur. The following fire can be free burning or affected by nearby objects, such as overlying ceiling (or similar) that do not let flames through. When a flame impinges on a ceiling, the gases will spread out radially (1) and establish extending flames under the ceiling. Heat distribution is dissimilar to free burning fires. How do flame extension length, mass flux, heat flux on the side of the fuel bed, rim temperature and liquid temperature correlate to the ceiling height above pool fires? Results give correlations useful in estimating mentioned parameters in the future. It is constructed an apparatus assigned pool fires with constant surface area of burning heptane and methanol liquid under a height adjustable ceiling. It is performed experiments by two squared burners with sizes of 0.25 and 0.40 m. Supply of fuel into the burner is equal to the fuel evaporated, which give constant liquid height related to both ceiling and burner rim. Flame images processed in MatLab is used to obtain flame lengths. Result contains obtained flame length, mass flux, heat flux and temperatures from various ceiling heights. The conclusion come out with an equation for estimating length of an extending flame under a ceiling.