Experimental study on the characteristics of horizontal flame spread over XPS surface on plateau.
Experimental study on the characteristics of horizontal flame spread over XPS surface on plateau.
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DOI：
10.1016/j.jhazmat.2011.01.101
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发表时间：
2011-05
影响因子：
13.6
通讯作者：
Ying Zhang;X. Huang;Qingsong Wang;J. Ji;Jinhua Sun;Yi Yin
中科院分区：
文献类型：
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作者：
Ying Zhang;X. Huang;Qingsong Wang;J. Ji;Jinhua Sun;Yi Yin
分别在拉萨高原和合肥平原进行了一系列室内对比实验，研究了典型保温材料挤塑聚苯乙烯泡沫塑料（XPS）的火焰传播特性。对火焰形状和固相温度分布进行了监测，分析了海拔高度对传热过程的影响。结果表明，温度随时间的上升经历了三个阶段：预热阶段、熔化阶段和热解阶段。平台区的熔融和热解阶段持续时间较平原区长，导致平台区火焰传播速率较低。对比高原和平原的温度变化率曲线发现，在热解阶段，温度变化率曲线的峰值特征由单峰变为多峰，说明海拔高度的差异可能改变了XPS材料的热解机理。此外，还探讨了样品尺度对火焰传播的影响。两个不同的制度被发现在两个高度的样品尺度的火焰传播行为。在对流区，扩散速率随样品尺度的增大而减小，在辐射区，扩散速率随样品尺度的增大而增大。
A series of comparative laboratory-scale experiments were carried out in the Lhasa plateau and the Hefei plain respectively to investigate the characteristics of flame spread over the extruded polystyrene (XPS) foam, a typical thermal insulation material. Flame shape and the temperature profile in solid phase were monitored, and the effects of altitude on the heat transfer process were analyzed. The results show that the temperature rise with time undergoes three stages: the preheating stage, the melting stage and the pyrolysis stage. The durations of the melting and pyrolysis stages on plateau are longer than that in plain, which sequentially results in a lower flame spread rate on plateau. Comparing of the temperature change rate curve on plateau with that in plain, it is found that the peak characteristics of the curves in the pyrolysis stage changed from single peak to multi-peaks, which suggests that the altitude difference might change the pyrolysis mechanisms of XPS material. Moreover, the sample scale effects on flame spread are also explored. Two different regimes are found in flame spread behavior with sample scale at the both altitudes. The spread rate drops with sample scale in convection regime and rises in radiation regime.