【摘要】 矿井环境中，电气火灾是诱发瓦斯与粉尘爆炸的重要因素，而线缆老化又是引起电气火灾主要原因。在高温、高电压等矿井工况下，导线易发生电热协同老化，然而现有研究多聚焦于单一应力对导线火灾行为的影响。为弥补该不足，构建电热协同老化平台，结合火蔓延测试和同步热分析(TG-DSC),对比研究两种尺寸聚乙烯(PE)导线在电热协同老化与热老化条件下的火蔓延特性与热稳定性。结果表明：电热协同老化组火蔓延速率及质量损失速率分别下降至热老化组的91%和71%,熔融滴落频率显著增加；同时，绝缘层熔融峰前移、分解峰后移，残炭率提升明显。研究揭示电热应力对导线燃烧与热解行为的协同影响，为矿井电力系统火灾风险评估与防爆安全提供理论依据。更多还原

【Abstract】 Electrical fires caused by cable degradation constitute a critical ignition source for gas and dust explosions in underground mining environments, where aged cable insulation serves as the primary contributing factor.Under harsh mining conditions, characterized by elevated ambient temperatures and high operating voltages, electrical cables experience accelerated electrothermal aging due to synergistic temperature-voltage degradation mechanisms.However, existing studies have primarily concentrated on investigating the influence of individual stress factors on cable fire behavior.To address this research gap, this study developed an electro-thermal synergistic aging platform and conducted comparative investigations of flame propagation characteristics and thermal stability for two different-sized polyethylene(PE) wires using flame spread tests and simultaneous thermal analysis(TG-DSC),under both electro-thermal synergistic aging and pure thermal aging conditions.The results demonstrate that electro-thermal synergistic aging, compared to thermal aging alone, reduces the flame spread rate and mass loss rate to 91% and 71%,respectively, while significantly increasing molten dripping frequency.Furthermore, the insulation layer exhibits an earlier melting peak, a delayed decomposition peak, and more substantial increases in residual carbon content.These findings elucidate the synergistic effects of electrical and thermal stresses on the combustion and pyrolysis behavior of PE wire, offering valuable theoretical insights for fire risk assessment and prevention in underground mining electrical systems.更多还原