不同钝体对正庚烷油池火燃烧行为的影响研究

Effect of Different Blunt Bodies on Combustion Behavior of N-Heptane Pool Fires

摘要: 油池火源常用于船舶机舱火灾的研究，而受机舱内大量设备的影响，在液体油池的形成过程中常含有各类形状的钝体结构物，这将极大地影响油池火焰的传热和流动特性。本文以正庚烷为火源，分别对含有不同形状(矩形、三角形、圆形、正方形)钝体的圆形油池火焰燃烧特性开展实验研究。通过对燃油质量损失速率、火焰几何形态的分析，研究结果表明钝体显著改变了油池火的燃烧行为。钝体延长了燃油质量消耗的时间，且正方形钝体可使质量损失速率下降迅速。虽然不同钝体下油池火焰均存在抬升–下降周期振荡行为，但其振荡频率却与钝体当量直径间存在三次方的非线性变化关系。

Abstract: Oil basin fires are commonly used in the study of ship cabin fires, and the formation of liquid oil basin often contains various shapes of blunt body structures due to the large amount of equipment in the cabin, which will greatly affect the heat transfer and flow characteristics of oil basin flames. In this paper, the flame combustion characteristics of a circular pool containing different shapes (rectangular, triangular, circular and square) of obtuse structures were experimentally studied using n-heptane as the ignition source. By analyzing the fuel mass loss rate and flame geometry, the results of the study showed that the obtuse body significantly changed the combustion behavior of the pool fire. Blunt bodies prolonged fuel mass depletion and square blunt body resulted in a rapid decrease in mass loss rate. Although the lifting-declining cycle oscillation behavior of the pool fire was observed for different obtuse bodies, the oscillation frequency was non-linearly varied in a cubic manner with the equivalent diameter of the obtuse body.