传湿及多维效应对建筑节点传热过程的影响分析

Influence of Moisture Transfer and Multidimensional Effects on the Heat Transfer Process of Building Nodes

对墙、板、梁、柱结合处的建筑节点结构进行准确传热过程分析是保证围护结构传热量精准计算的前提。目前针对建筑节点结构传热问题的研究主要有两种方法:一种是考虑多维效应,利用纯传热模型求解,但没有考虑湿传递对传热的影响;另一种是从一维热湿传递的角度对节点结构传热传湿进行简化,忽略多维效应对传热的影响。因此以常见的二维建筑节点结构为研究对象,建立多维热湿耦合传递数学模型,分析了建筑节点结构的内表面热流分布特征,对比了多维热湿耦合模型、多维纯传热模型、一维热湿耦合传递模型和一维纯传热模型在计算建筑节点结构传热量中的差异。研究结果表明:传湿过程使得建筑节点结构传热量的增加为3.7%~14.2%;如果将建筑节点结构传热过度简化为一维传热计算会导致传热量被低估2.5%~31%。因此,对建筑节点传热量的准确计算需考虑传湿和多维效应的综合影响。

Accurate analysis of heat transfer process of building joint structure at the joint of wall, slab, beam and column is the precondition to ensure accurate calculation of heat transfer of envelope structure. At present, there are two main methods to study the heat transfer of building joints: one is to consider the multi-dimensional effect and solve it by using pure heat transfer model, but not considering the effect of moisture transfer on heat transfer;The other is to simplify the heat and moisture transfer of the joint structure from the angle of one-dimensional heat and moisture transfer, ignoring the multi-dimensional effect on the heat transfer. Therefore, a multi-dimensional coupled heat and moisture transfer mathematical model is established for the common two-dimensional building joint structure, and the characteristics of heat flow distribution on the inner surface of the building joint structure are analyzed, the differences among multi-dimensional heat and moisture coupled model, multi-dimensional pure heat transfer model, one-dimensional heat and moisture coupled model and one-dimensional pure heat transfer model in calculating the heat transfer of building joints are compared. The results show that the heat transfer capacity of the building joint structure is increased by 3.7%~14.2% due to the moisture transfer process, and the heat transfer capacity is underestimated by 2.5%~31% if the heat transfer of the building joint structure is over simplified to one-dimensional heat transfer calculation. Therefore, the combined effects of moisture transfer and multi-dimensional effects should be considered in the accurate calculation of heat transfer of building nodes.