导线间距对倾斜平行双导线火蔓延特性的影响研究

Study on the effect of separation distance on the fire spread characteristics of inclined parallel twin wires

以双根平行聚乙烯铜导线为研究对象,开展了导线倾角为0~90°、间距为0~17 mm的一系列火蔓延试验,分析了燃烧过程中火焰形态、火焰高度、长度以及火蔓延速率的变化规律。结果表明:(1)倾斜平行双导线的火焰形态随导线间距增大会经历3个阶段:融合阶段、靠近阶段以及独立阶段;(2)双导线火焰高度(除90°倾角外)、火焰长度、火蔓延速率均随倾角增大而增大,随间距增加表现为先增大后减小趋势;(3)双导线火蔓延速率起初小于单导线,随着导线间距增加而增大并在融合后期达到峰值,随后逐渐减小并在独立阶段与单导线保持一致;(4)建立了双导线火蔓延速率与火焰长度的正比关系,其比例系数为0.078,比单导线的比例系数略小。

In this paper,a series of experiments were performed over twin parallel polyethylene copper wires with inclination angles from 0 to 90°and spacing from 0 to 17 mm,to analyze the flame pattern,flame height,length and fire spread rate during the combustion process.The results show that:(1)The flame form of inclined parallel twin wires at different distances goes through three stages such as the integrated stage,the approached stage and the independent stage;(2)both flame height(except 90°inclination),flame length,and fire spread rate of twin wires all increase with increasing inclination,while increase and then decrease with increasing spacing;(3)the fire spread rate of the twin wires was initially smaller than that of the single,gradually increased with the wire spacing and reached a maximum in the late stage of integration,and then decreased and remained identical to that of the single in the independent stage;(4)the proportional relationship between the fire spread rate and the flame length is established,and the proportional coefficient is 0.078 for fire spread over twin parallel wires,which is slightly smaller than that for the single wire.