摘要：In this paper, three types (typeⅠ, type Ⅱand type III) of polyethylene-insulated wires with copper core diameters of 6 mm, 8 mm and 10 mm and thickness of polyethylene of 2 mm respectively, were used to research the flame spread of double wires with spacing sizes of 0 mm,1 mm,2 mm,3 mm,5 mm,7 mm,10 mm,12 mm, 15 mm and 18 mm. The results showed that with the increase of spacing, the flame changed from “less propagating” to “quasi-intermittent merging” stage, to “continuous merging” stage, then to “intermittent merging” stage, and finally to “non-merging” stage. For type III of the largest Cu core diameter, the flame could not spread when s = 1 mm and 2 mm.After that, the same transition from''continuous merging” stage to “non-merging” stage was found. The flame width showed the similar trend with FSR for typeⅠand type Ⅱ, while for type III the correlation between flame width and FSR was not closely related. The mass loss rate and mass dripping rate showed the similar trends with FSR. The faster FSR, the larger mass loss and dripping rates. The “re-burning” phenomena were found during the process of flame spread with small spacing distances, which made the residual material PE ignite again, and the flame width increase.
关键词：Polyethylene-insulated wire Wire spacing Air entrainment Flame spread Flame merging
