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Multiphysics Modelling of Stone Wool Fire Resistance
Fire Technology ( IF 3.4 ) Pub Date : 2020-10-20 , DOI: 10.1007/s10694-020-01050-5
Deepak Paudel , Aleksi Rinta-Paavola , Hannu-Petteri Mattila , Simo Hostikka

In fire resistance tests, stone wool’s organic matter undergoes exothermic oxidative reactions sustained by external heat, causing mass transfer in the structure. The previous modelling attempts, lacking the mass transfer physics, fall short in predicting the temperature of high density and high organic content samples. To fill this gap in the fire engineering modelling capability, we include mass transfer in our calculation, and validate the model using experimental fire resistance data. As an alternative, we use a heat conduction -based model lacking the gas transfer but with reaction kinetics coupled to the stone wool’s organic mass %. The results show that the thermal effects of the oxidative degradation can be predicted by introducing the simplified diffusion processes. The oxygen transfer and exothermic reactions depend upon the amount of organic content, and the uncertainty of temperature predictions is $$\pm \,20\%$$ . In average, temperatures and critical times are more accurately predicted by the heat conduction model, while, the peak temperature prediction uncertainty is low ( $$\pm \,10\%$$ ) with the multiphysics model. The uncertainty compensation method reduces the difference between the two model predictions. Nevertheless, further validation study is needed to generalize the uncertainty compensation metrics. Finally, we demonstrate how a gas flow barrier on the cold side (sandwich) can effectively reduce the peak temperature of the high organic content-stone wools.

中文翻译:

石棉耐火性的多物理场建模

在耐火测试中,岩棉的有机物质在外部热量的作用下发生放热氧化反应,导致结构中的传质。之前的建模尝试缺乏传质物理学,无法预测高密度和高有机含量样品的温度。为了填补消防工程建模能力的这一空白,我们在计算中加入了传质,并使用实验耐火数据验证模型。作为替代方案,我们使用基于热传导的模型,该模型缺乏气体传递,但反应动力学与岩棉的有机质量 % 相关联。结果表明,可以通过引入简化的扩散过程来预测氧化降解的热效应。氧气转移和放热反应取决于有机物含量,温度预测的不确定性为 $$\pm \,20\%$$ 。平均而言,热传导模型可以更准确地预测温度和临界时间,而多物理场模型的峰值温度预测不确定性较低 ($$\pm\,10\%$$)。不确定性补偿方法减少了两个模型预测之间的差异。然而,需要进一步的验证研究来概括不确定性补偿指标。最后,我们展示了冷侧(夹心)上的气流屏障如何有效降低高有机含量岩棉的峰值温度。热传导模型可以更准确地预测温度和临界时间,而多物理场模型的峰值温度预测不确定性较低 ($$\pm\,10\%$$)。不确定性补偿方法减少了两个模型预测之间的差异。然而,需要进一步的验证研究来概括不确定性补偿指标。最后,我们展示了冷侧(夹心)上的气流屏障如何有效降低高有机含量岩棉的峰值温度。热传导模型可以更准确地预测温度和临界时间,而多物理场模型的峰值温度预测不确定性较低 ($$\pm\,10\%$$)。不确定性补偿方法减少了两个模型预测之间的差异。然而,需要进一步的验证研究来概括不确定性补偿指标。最后,我们展示了冷侧(夹心)上的气流屏障如何有效降低高有机含量岩棉的峰值温度。需要进一步的验证研究来概括不确定性补偿指标。最后,我们展示了冷侧(夹心)上的气流屏障如何有效降低高有机含量岩棉的峰值温度。需要进一步的验证研究来概括不确定性补偿指标。最后,我们展示了冷侧(夹心)上的气流屏障如何有效降低高有机含量岩棉的峰值温度。
更新日期:2020-10-20
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