Burning characteristics of conduction-controlled rectangular hydrocarbon pool fires in a reduced pressure atmosphere at high altitude in Tibet

Abstract

The burning characteristics of conduction-controlled rectangular hydrocarbon pool fires in a reduced pressure atmosphere have not been revealed in the past. In this paper, rectangular pool fires with same area S (36cm2) but different aspect ratios (L/W=1, 2, 3, 4) are burnt correspondingly in both normal (100kPa; Hefei altitude 50m) and reduced (64kPa; Lhasa-altitude 3650m) pressure atmosphere. Ethanol and n-heptane are used as fuel. Results show that the burning characteristics of conduction-controlled rectangular pool fires are quite different from those reported for radiation-controlled ones in the literatures. The burning rate of a conduction-controlled pool fire increases with aspect ratio, but does not change with pressure. The flame height in reduced pressure is higher than that in normal pressure. A global factor is developed for flame height correlation to account for both pressure and pool dimension aspect ratio effects. The flame radiation flux increases with increase in aspect ratio, being slightly lower in the reduced pressure than that in the normal pressure atmosphere. Meanwhile, the flame radiation fraction is nearly independent of both pool aspect ratio and pressure.