Heat and Mass Transfer Through Gypsum Partitions Subjected to Fire Exposures
Heat and Mass Transfer Through Gypsum Partitions Subjected to Fire Exposures
复制标题
通过受火暴露的石膏隔断进行传热和传质
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
S. Kukuck
中科院分区：
文献类型：
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作者：
S. Kukuck
提出了一个描述石膏墙板隔板组件的传热模型，该模型考虑了液体和蒸汽形式的水的传质效应。水的来源包括表面结合(吸附)水和与石膏晶体基质化学结合的水合水。释放的水通过分子扩散和压力驱动流通过多孔结构迁移。当水蒸气与孔隙空间的分压小于饱和压力或大于饱和压力时，分别发生蒸发或凝结。将该模型得到的结果与标准耐火试验中的测量结果进行了比较。结果发现，尽管观测到了定性相似的行为，但表面温度通常被低估了。分析表明，液体和水蒸气形式的水的释放和传输对石膏墙板在火灾暴露下的热响应起着重要作用，甚至可能超过当前模型的发展程度。该模型可用于在建立模型的假设条件下，对物理参数进行灵敏度研究，并评估其对系统耐火性能的影响。
A model is presented that describes the heat transfer through a gypsum wallboard partition assembly incorporating the mass transport effects of water in liquid and vapor form. Sources of water include surface bound (adsorbed) water and hydrated water that is chemically bound with the crystal matrix of gypsum. Liberated water is allowed to migrate through the porous structure through molecular diffusion and pressure driven flow. Evaporation or condensation occurs when the partial pressure of water vapor with the pore space is less than or greater than the saturation pressure, respectively. Results obtained from the model are compared to measurements taken during a standard fire resistance test. It is found that the surface temperatures are typically under-predicted, although qualitatively similar behavior is observed. The analysis implies that the liberation and transport of water in both its liquid and vapor form plays a significant role in the thermal response of gypsum wallboard subjected to fire exposures, perhaps even beyond the extent to which the current model has been developed. The model can be used, under the assumptions through which it was developed, to conduct sensitivity studies of the physical parameters and evaluate the effect upon the fire resistance of the system.