In this study, the flame spread over a thin wire with overload current (0‐16 A) has been experimentally investigated at both normal pressure (Hefei: altitude 50 m, 100 kPa) and reduced pressure (Lijiang: altitude 2400 m, 76 kPa; Lhasa: altitude 3650 m, 64 kPa). Polyethylene‐insulated single‐core wires, comprising Cu as the inner core of diameter 0.30, 0.50, and 0.80 mm and insulation thickness 0.15 and 0.30 mm, are used as samples. The experimental results clearly indicate that the height of the flame increases with the electric current and ambient pressure, but the flame width changes only slightly. At identical conditions, the finer the wire, the faster the flame spreads. The flame spread rate increases with the electric current and ambient pressure. A simplified thermal balance analysis concerning the load current is developed to calculate the flame spread rate, and the calculated flame spread rates are shown to be fairly consistent with the experimental values at different electric currents for different wires at both ambient pressures. In addition, the coupled effect of electric current and ambient pressure on the flame spread is discussed. These results may be meaningful for promoting the research process of wire fire safety.

中文翻译：

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在变化的压力和电流下，PE绝缘的单芯铜芯线上火焰蔓延的实验研究

在本研究中，已经对在正常压力（合肥：海拔50 m，100 kPa）和减压（丽江：海拔2400 m，76 kPa）下通过火焰进行了研究，研究了火焰在细线上以过载电流（0-16 A）扩散的情况。 ；拉萨：海拔3650 m，64 kPa）。聚乙烯绝缘单芯线，以Cu为内芯，直径为0.30、0.50和0.80 mm，绝缘厚度为0.15和0.30 mm，用作样品。实验结果清楚地表明，火焰的高度随电流和环境压力的增加而增加，但火焰宽度仅略有变化。在相同条件下，导线越细，火焰传播越快。火焰扩散率随电流和环境压力的增加而增加。开发了一种关于负载电流的简化热平衡分析，以计算火焰扩散率，并且在两个环境压力下，针对不同电线，在不同电流下，计算得出的火焰扩散率与实验值相当一致。另外，讨论了电流和环境压力对火焰蔓延的耦合作用。这些结果对于促进电线防火安全的研究过程可能具有重要意义。