HEAT-TRANSFER IN SMALL-SCALE POOL FIRES

The heat transfer mechanisms of liquid fuel pool fires in small cylindrical vessels were studied. The longitudinal temperature distribution of the vessel wall and the liquid burning rate at the fixed liquid depth with vessels of various materials and wall thickness were measured, and also calculated by the finite difference program under some assumptions. It was confirmed that the heat that is transferred from the flame to the top of the vessel and conducted through the wall and then transferred convectively to the liquid fuel is dominant compared with the direct conductive and radiative heats from the flame to the liquid. The measured vessel wall temperature distribution and steady burning rate agreed well at relatively shallow liquid depth with the calculated results. In the case of vessels of very poor thermal conductivity and thinner vessels of good thermal conductivity, the agreement is good. However, in the case of thicker vessels of good thermal conductivity the calculated burning rate tends to become comparatively larger than the measured one, perhaps due to the heat loss through the base of the vessel. It is considered to be due to the deviation of the temperature contour at the base of the flame from the assumed one that the calculated burning rate deviates from the measured one increasingly with the liquid depth.