保温材料热阻蜕变对墙体传热系数的影响  

Effect of Thermal Resistivity Deterioration of Insulation Materials on the Heat Transfer Coefficient of Walls

作　　者：苏向辉[1] 陈玮玮[1] 唐敢[2] 

机构地区：[1]南京航空航天大学航空宇航学院,南京210016 [2]东南大学土木工程学院,南京210096

出　　处：《建筑科学》2012年第3期25-28,16,共5页Building Science

基　　金：国家自然科学基金(51008067)

摘　　要：外保温结构中保温材料的有效热阻随温度、湿度和使用年限的增加而下降,造成墙体传热系数大于设计值。为此,本文以耦合传热传湿模型为基础,结合保温材料的有效导热系数模型,以分别采用发泡聚苯乙烯,挤塑聚苯乙烯和聚氨酯泡沫作为保温材料的外墙保温结构为例,数值预测了长期实际气候下外墙保温结构的传热系数。计算结果表明,采用上述三种保温材料的墙体传热系数在20年后因保温材料热阻蜕变有不同程度的增加,这意味着需要增加保温层设计厚度才能保证墙体热损失达到设计值。The effective thermal resistivity of insulation materials in exterior insulation constructions decreases with increasing temperature,moisture content and age.Hence,heat transfer coefficients of the wall may become higher than the design values.In this paper,the heat transfer coefficients for exterior insulation constructions with expanded polystyrene,extruded polystyrene and polyurethane foam under long-term climatic condition are predicted by combining heat and moisture transfer models with effective thermal conductivity models of these insulations.The presented numerical results show that the heat transfer coefficients of the wall with these insulations increase to various degrees after 20 years due to the deterioration of insulations.This means that there is a need of increasing insulation design thickness to meet the design values of thermal losses.

关 键 词：建筑围护结构 热阻保留率 保温材料 传热系数 

分 类 号：TU111.4[建筑科学—建筑理论] TU111.19