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过电流铜包铝导线线芯发热及绝缘燃烧规律研究 被引量:6
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作者 林庆文 王鑫玉 +2 位作者 李阳 冯骁 何芬芬 《消防科学与技术》 CAS 北大核心 2021年第2期168-171,共4页
为准确研究铜包铝导线在不同过电流值条件下的线芯发热及绝缘燃烧现象。以2.5 mm2 PVC多股铜包铝导线为研究对象,分别模拟导线发生40、50、60、70、80 A过电流故障,利用高速影像及视频分析技术研究过电流导线线芯发热、熔断、电弧引燃... 为准确研究铜包铝导线在不同过电流值条件下的线芯发热及绝缘燃烧现象。以2.5 mm2 PVC多股铜包铝导线为研究对象,分别模拟导线发生40、50、60、70、80 A过电流故障,利用高速影像及视频分析技术研究过电流导线线芯发热、熔断、电弧引燃及绝缘燃烧随电流值的变化规律。结果表明:当过电流值小于40 A时,导线仅线芯发热、绝缘热解发烟,不会出现线芯熔断现象;当过电流值大于50 A时,导线的线芯发热加剧,熔断时间越来越短,由50 A时的平均120.8 s降为了80 A时的19.8 s;当I=50 A时,电弧引燃周围的热解气体,形成最大8.4 cm范围内的燃烧,当I≥60 A时,电弧引燃后的火焰会蔓延至导线左端和右端,但火焰的蔓延速率随着电流值的升高先加快再减慢,70 A时最快,平均可达7.13 m/s。 展开更多
关键词 电气火灾 过电流故障 铜包铝导线 线芯发热 绝缘燃烧
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Thermogravimetric study of the effect of a PVA oxygen-insulating barrier on the spontaneous combustion of coal 被引量:5
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作者 MENG Xianhang CHU Ruizhi +3 位作者 WU Guoguang XU Hongfeng ZHU Jiamei WANG Zhihua 《Mining Science and Technology》 EI CAS 2010年第6期882-885,共4页
Coal samples in the air for three months were characterized by Thermogravimetric Analysis (TGA). The effect of a PVA oxygen-insulating barrier on the spontaneous combustion of coal was examined. The moisture loss acti... Coal samples in the air for three months were characterized by Thermogravimetric Analysis (TGA). The effect of a PVA oxygen-insulating barrier on the spontaneous combustion of coal was examined. The moisture loss activation energy, oxidation activation energy and combustion activation energy were calculated by an integral method using the Coats-Redfen formula. The results show that the tendency for spontaneous combustion of three coal samples (judged by the activation energy) falls in the order: CYW>YJL>SW. The oxidation activation energy and combustion activation energy of coal protected by the PVA oxygen-insulating barrier increased. A significant increase in the combustion activation energy was noted, especially for the CYW coal where the in-crease was 28.53 kJ/mol. Hence, oxidation of the protected coal samples was more difficult. The PVA oxygen-insulating barrier helps to prevent spontaneous combustion of the coal. 展开更多
关键词 coal spontaneous combustion oxygen-insulating barrier activation energy thermogravimetric analysis
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