夏热冬冷地区居住建筑围护结构的动态多维热湿耦合传递与节能优化研究

Residential buildings in the "Hot-summer Cold-winter" region of China feature intermittent and localized energy utilization. The coupled heat and moisture transfer through building envelope structures has significant influence on energy consumption and control of indoor thermal environment. This proposed project will measure systematically the key hygrothermal transport properties of typical porous building materials. Effect of moisture content on the thermal conductivity and temperature-dependence of the moisture transfer coefficient of the porous building materials will be studied, and a hygrothermal transport property database will be established. The transient multi-dimensional coupled heat and moisture transfer processes through building envelope structures under specific boundary conditions will be studied numerically and experimentally. Simplified correlations will be proposed to simulate the building energy consumption and indoor thermal environment with application to engineering practices in the "Hot-summer Cold-winter" region of China. Based on the climatic characteristics (hot and cold with high humidity levels) and the intermittent and localized energy-use mode of residential buildings in this region, energy-saving optimization schemes of the building envelope structures will be proposed and tested with the aid of the results from the coupled heat and moisture investigations. The effects of construction of self-insulation and thermal bridge insulation on the energy-saving efficiency and indoor thermal environment control will also be revealed. The contents of this proposed project represent the future research of coupled heat and moisture transfer in building envelope structures. The expected results of this project will provide theoretical fundamental and quantitative support for energy conservation and improvement of indoor thermal environment of residential buildings in the "Hot-summer Cold-winter" region of China.

夏热冬冷地区的居住建筑具有明显的间歇式和分室用能特征，其围护结构的耦合热湿传递过程对建筑能耗和室内热湿环境调控有重要的影响。本申请项目将对围护结构典型多孔材料的关键热湿传递物性进行系统性地测试，总结出其导热系数随含湿量以及传湿系数随温度的变化规律，建立起较为丰富的热湿传递物性数据库。对特殊边界条件下围护结构的热湿耦合传递过程进行动态多维模拟和实验研究，归纳出可用于夏热冬冷地区工程实践的建筑能耗和室内热湿环境模拟简化公式。结合该地区湿热湿冷的气候特色和以间歇式分室用能为特征的居住建筑用能模式，在热湿耦合传递研究的基础上提出合理的围护结构节能优化方案并对其性能进行评估，掌握不同保温形式和热桥部位保温构造对节能效率和室内热湿环境的调控规律。本申请项目的研究内容代表了围护结构热湿耦合传递研究的未来发展方向，其研究成果将为夏热冬冷地区建筑节能工作的开展和室内热湿环境的改善提供理论依据和数据支持。

夏热冬冷地区居住建筑围护结构的耦合热湿传递过程对建筑能耗和室内热湿环境调控有重要的影响。本项目采用实验与数值模拟相结合的方法开展相关研究。.首先较为详细地研究了多孔建筑材料（以蒸压加气混凝土为主）的热物理特性，测试不同孔隙率时含湿蒸压加气混凝土的有效导热系数，获得了加气混凝土有效导热系数与质量含水量和孔隙率的实验关联式；基于分形理论分析了孔隙结构对绝干状态和含湿状态的加气混凝土导热系数的影响，建立了多孔材料导热系数预测模型；并探讨了相变材料对加气混凝土有效导热系数的影响。.其次提出两种基于求解瞬态一维质扩散反问题的多孔材料水蒸气扩散系数瞬态测试方法并搭建测试实验系统，测试数据与文献报道值、稳态测试结果吻合较好，加气混凝土的水蒸气有效扩散系数受孔径分布而非孔隙率的影响，并随温度的升高而增大。.针对围护结构热湿耦合传递过程及节能优化方面，展开了多孔建筑材料热湿耦合数值模拟，建立多孔介质的热、空气、湿耦合传递模型，探究了温度对水蒸气扩散系数的影响；进行实际环境条件下典型建筑材料的热湿耦合传递过程实验，分析太阳辐射对传递过程的影响；综合考虑砌筑砂浆热工性能、自保温砌块热工性能、结构性热桥等因素进行基于稳态传热模拟的自保温系统热工性能研究，分析了房间开间宽度、窗墙比等对墙体平均传热系数的影响；搭建设置不同类型热桥和自保温墙体的实验楼，测量并分析温度和热流等参数变化。实验结果发现：采用半包柱构造的T型楼板热桥能有效减少热流损失，蒸压加气混凝土砌块和夹心保温砌块时热桥处的保温性能要优于烧结页岩多孔砖。基于夏热冬冷地区间歇式分室的用能模式开展内外综合保温体系节能分析，提出一种内外综合保温体系，并给出该体系中外墙保温层的最佳厚度配比方案。项目的研究结果是对建筑材料热物性测试和围护结构热湿耦合传递基础研究的有益补充，为夏热冬冷地区建筑节能工作的开展和室内热湿环境的改善提供了实验依据和技术参考。