液化石油气层流燃烧火焰特性分析

Analysis of Flame Characteristics of Laminar Combustion of Liquefied Petroleum Gas

应用实验测试的方法对常温常压下不同配比的液化石油气/空气的燃烧特性进行研究,获得了水平管内火焰传播速度、火焰中心温度、火焰高度等随着液化气体积分数的变化规律。结果表明:火焰传播速度随着液化石油气体积分数的增大先增大后减小,最大值出现在体积分数为2. 78%处,即当量比为0. 98;不同燃烧方式火焰中心温度沿高度方向变化规律不同,扩散火焰的温度分布均匀;半预混火焰温度沿高度方向先上升后下降;全预混火焰中心温度随火焰高度的增加而下降;火焰高度随着液化石油气体积分数变化而变化,在当量比小于1时,火焰高度随着液化石油气体积分数的减小而降低,当接近化学当量比时达到最低;当量比大于1后,随着液化石油气体积分数减小,火焰高度增加。

An experimental study on laminar burning characteristics of liquefied petroleum gas(LPG)/air flames were conducted under normal temperature and atmospheric pressure.The variation laws of laminar flame propagation velocity in horizontal tube,the flame center temperature distribution,and the flame height with different LPG fraction in fuel were obtained.The results show that flame propagation velocity increases with LPG fraction in fuel lean region,then decreases in the fuel rich region,and the maximum propagation velocity appears in 2.78% volume fraction and at equivalence ratio 0.98.The temperature distribution of flame center is different in different combustion mode,and the temperature distribution of diffusion flame is uniform,the semi-premixed flame temperature rises first and then decreases along the height,and the temperature of the full premixed flame decreases with the increase of flame height.The flame height changes with the volume fraction of LPG,and it decreases with the decrease of the volume fraction of LPG,with the minimum at equivalent ratio of 1.With the equivalent ratio greater than 1,as the volume fraction of liquefied petroleum gas decreases,the flame height increases.