湿热地区建筑外饰面蒸发过程对建筑能耗的影响

The summer season in the hot and humid regions of China is characterized by frequent rainfall and intense solar radiation, so the building external layer exists Water Absorption and Evaporation (WAE) processes. Although the cooling mechanism of the WAE processes is explicit, the influence patterns of the climatic factors and material performances on the WAE processes are still indefinite which lead to the problem that the energy efficiency of the evaporative cooling technology can not be evaluated scientifically. In order to solve this issue, this project intends to carry out the following studies. (1) Research the influence of pore characteristics of facing material on the water absorption performance. Conduct the capillary water absorption experiment of facing materials. Establish the water absorption calculation model based on the precipitation amount, rainfall duration, initial moisture content and pore characteristics. (2) Study the dynamic evaporation process of the facing materials by using the thermal climatic wind tunnel. Analyze the influence of outdoor climatic factors and pore characteristics on the evaporation rate. A multivariate nonlinear regression analysis method is used to establish the calculation model of evaporation rate. (3) Develop the evaporation calculation model based on the building energy simulation software. Integrating the moisture content model and evaporation amount model of facing materials into the surface heat and moisture balance equations. Realize the dynamic simulation of the influence of evaporation process on building energy consumption. (4) Carry out the multiple objective optimization research of facing materials and building main structures, develop the innovative building envelope construction.

我国湿热地区，夏季降雨丰沛，太阳辐射强烈，建筑外饰面存在吸水和蒸发过程。尽管该过程的降温机理已经清楚，但气象因素和材料属性对该过程的影响规律依然模糊，导致无法科学评估蒸发降温技术的节能效益。为了解决该问题，拟开展以下工作。.（1）研究饰面材料孔隙特征对吸水性能的影响规律，开展饰面材料毛细吸水实验，以孔隙特征，初始含水率和吸水时间为自变量，建立吸水率计算模型。.（2）采用热湿气候风洞实验台研究饰面材料的动态蒸发过程，分析气象因素和材料属性对蒸发率的影响规律，采用多元非线性回归分析方法建立蒸发率计算模型。.（3）在建筑能耗模拟软件中，开发蒸发降温计算模块，将吸水率和蒸发率计算模型整合到建筑外表面热湿平衡方程中，实现蒸发过程对建筑能耗影响的动态模拟。.（4）开展饰面材料与建筑主体结构组合形式的多目标优化研究，研发基于蒸发降温原理的新型建筑节能构造。

我国湿热地区，夏季降雨丰沛，太阳辐射强烈，建筑外饰面存在吸水和蒸发过程。尽管该过程的降温机理已经清楚，但气象因素和材料属性对该过程的影响规律依然模糊，导致无法科学评估蒸发降温技术的节能效益。为了解决该问题，本项目在国家自然科学基金项目的资助下，重点研究了以下内容：采用部分浸泡法研究了建筑多孔材料的吸水特性，获得了常用建筑多孔饰面砖的吸水曲线，通过对吸水曲线毛细吸水阶段的线性拟合，获得多孔饰面砖的毛细吸水系数，从而建立了吸水率计算模型。在热湿气候风洞中研究了太阳辐射、空气温度、空气湿度和空气流速对多孔材料蒸发速率的影响规律，通过正交实验分析，得到了上述气候参数对蒸发速率影响的显著性水平。研究结果表明，太阳辐射是影响多孔材料表面蒸发的关键因子，其次是空气温度，水蒸气分压力和风速，说明在我国湿热地区尽管空气中湿度较大，但由于有充沛的太阳辐射和降雨，仍然具有应用蒸发降温技术的潜力。通过回归分析太阳辐射、空气温度、空气湿度和空气流速与蒸发速率之间的相关关系，建立了蒸发速率多因子预测模型，该模型可以快速预测蒸发速率变化趋势，适用于长时间尺度的建筑能耗仿真中，模拟蒸发降温对建筑能耗的影响。开发了多孔饰面砖的蒸发降温计算程序，并对建筑能耗仿真平台EnergyPlus的源代码进行了更新，在建筑外表面热量平衡方程中增加了蒸发潜热量源项，通过EnergyPlus的二次开发，将多孔饰面砖蒸发量计算模型集成到建筑能耗的动态计算过程。在本项目的资助下，发表期刊论文18篇，其中SCI检索论文10篇，EI检索1篇，授权实用新型专利1项，培养毕业博士研究生2人，硕士研究生2人，本项目负责人作为第9完成人获得2018年华夏建设科学技术奖励一等奖。