摘要
膨胀型防火涂层在膨胀过程中孔隙存在的对流传热和辐射传热会降低涂层的防火性能。考虑到孔隙之间存在涂层分解产生的气体,因此通过理想气体状态方程,描述了涂层在不同升温条件下的膨胀行为。建立了以膨胀尺寸为输出项,并考虑孔隙对有效导热系数增强作用的有限元传热模型,探究不同厚度的涂层在不同升温环境下的防火性能。结果表明:膨胀尺寸模型能够较为准确地预测涂层在不同温度场下的膨胀行为,涂层最大膨胀率随干膜厚度增大而减小;基于膨胀尺寸和多孔有效导热系数的有限元传热模型模拟的钢管温度变化与试验结果吻合较好;膨胀型防火涂层在高升温速率环境中能够明显延缓钢管升温,并降低其最大受火温度;不同升温环境中,涂层的防火能力和厚度呈非线性变化。
The heat transfer and radiative heat transfer in the pore will reduce the fire resistance of the coating.Considering the existence of gas produced by the decomposition of the coating between the pores,this paper describes the expansion behavior of the coating under different heating conditions through the ideal gas state equation.A finite element heat transfer model was established,which took expansion size as output term and the enhancement effect of pores on effective thermal conductivity,to explore the fire performance of coatings with different thickness under different heating environments.The results show that the expansion size model can accurately predict the expansion behavior of the coating at different temperature fields,and the maximum expansion rate of the coating decreases with the increase of the dry film thickness.The finite element heat transfer model based on the expansion size and the effective thermal conductivity of the pores is in good agreement with the experimental results.In the high heating rate environment,the intumescent coating can significantly delay the heating of steel tube and reduce its maximum fire temperature.Under different heating conditions,the fire resistance and thickness of the coating change nonlinearly.
作者
康涵
李明海
张兆强
姚勇
KANG Han;LI Ming-hai;ZHANG Zhao-qiang;YAO Yong(School of Civil Engineering and Architecture,Southwest University of Science and Technology,Sichuan Mianyang 621010,China;Institute of Systems Engineering,China Academy of Engineering Physics,Sichuan Mianyang 621000,China)
出处
《消防科学与技术》
CAS
北大核心
2022年第7期974-977,共4页
Fire Science and Technology
基金
工程材料与结构冲击振动四川省重点实验室开放基金项目(18kfgk14)。
关键词
多孔介质
膨胀型防火涂层
膨胀行为
有限元模拟
温度场
porous media
intumescent coating
expansion behavior
finite element simulation
temperature field
