Flame merging of line fires is very complex with the interaction of fire dynamics and fluid flow et al., which will often generate different burning behaviors. In this paper, the effects of spacing distance and fuel mass thickness on the combustion and flame merging characteristics of two n-heptane line pool fires were studied. With the dimensionless liquid fuel height H* (Fuel height/Groove depth) increase, the probability of flame merging, and the temperature of the additional air entrainment region gradually increase. The merging flame will change from no hole, with hole, hole increased to hole open stage with spacing distance increase. It is interesting to find that, the mass loss rate of each line fire is less than that of a single line fire burning alone, and the closer the distance is, the smaller the value is. Meanwhile, for a single or double linear fires at H* = 3/4, the mass loss rate is the greatest. By establishing a heat transfer model, it is demonstrated that at H* = 3/4, the ullage of the groove has a stabilizing effect on the flame, which makes the flame height the largest. The results of this study will enhance the understanding of the flame merging of line fires with different fuel masses.

线火的火焰合并非常复杂，火动力学和流体流动等相互作用，往往会产生不同的燃烧行为。本文研究了间距和燃料质量厚度对两种正庚烷管线池火燃烧和火焰融合特性的影响。随着无量纲液体燃料高度H*（Fuel height/Groove depth）的增加，火焰合并的概率和附加空气夹带区域的温度逐渐增加。融合火焰将从无孔、有孔、有孔增加到孔间距增加的开孔阶段。有趣的是，每条线火的质量损失率小于单线火单独燃烧的质量损失率，而且距离越近，数值越小。同时，对于 H* = 3/4 时的单线或双线火灾，质量损失率最大。通过建立传热模型，证明在H*=3/4时，凹槽的空缺对火焰有稳定作用，使得火焰高度最大。这项研究的结果将增强对不同燃料质量的线火火焰合并的理解。