Lip-height effect in diffusive pool fires
Einar Arthur Kolstad, Vidar Frette, Ulrich Krause, Bjarne Christian Hagen
Abstract
A freeboard, lip height, from the container rim to the fuel surface affects the mass-loss rate of a pool fire. Experiments where heptane was burned in circular containers with diameter 10, 20 and 30 cm have been conducted. The results showed a decrease of up to 36% in the mass-loss rate for lip heights larger than zero. The mass-loss rate per unit area is affected by the lip height enough for it to surpass the effect of the diameter: a large-diameter pool fire with a high lip height may have lower mass-loss rate per unit area than a pool fire with smaller diameter and lower lip height. An analysis of the energy distribution for one experiment, showed that 35% of the received energy was lost to the surroundings; 30% was stored, and 35% was spent on evaporating fuel.