附加式屋顶通风结构二维简化传热分析

降低建筑能耗对于发展低碳建筑至关重要，屋顶的热量得失对建筑能耗的影响不容忽视。基于屋顶通风隔热结构，本文提出并介绍附加式屋顶通风隔热结构的隔热原理，分析其传热过程，采用数值模拟的方式，以当量热阻的概念来研究该通风结构的热工特性变化规律。结果表明，在稳态条件下，对于确定的附加式屋顶通风结构，通风腔当量热阻与太阳辐射强度、室外空气温度存在指数关系；在同一室外空气温度下，通风腔当量热阻存在最大值；其当量热阻最大值与隔热材料表面发射率倒数、室外空气温度及材料热阻比值呈线性关系；运用得到的计算关系对附加式屋顶通风结构在不同地区的热工特性进行了分析。

Two-dimensional Simplified Heat Transfer Analysis of Structure of Additional Roof Ventilation

Reducing energy consumption in buildings is crucial to the development of low-carbon buildings. The impact of roof heat gain and loss on building energy consumption cannot be ignored. Based on the roof ventilation and heat insulation structure, this paper proposes and introduces the principle of a supplementary roof ventilation and insulation system, analyzes its heat transfer process, and employs numerical simulation to investigate the thermal characteristics of the ventilation structure. The results show that there is an exponential relationship between the equivalent thermal resistance of the ventilation cavity and the solar radiation intensity and outdoor air temperature for the determined additional roof ventilation structure under steady state conditions. At the same outdoor air temperature, the equivalent thermal resistance of the ventilation chamber has the maximum value. The maximum equivalent thermal resistance is linearly correlated with outdoor air temperature, material thermal resistance ratio and reciprocal of surface emissivity of thermal insulation material. The thermal characteristics of additional roof ventilation structure in different areas are analyzed by using the calculated relation.