建筑墙体及室内环境热湿空气耦合传递机理的多尺度研究

Low energy comsumption and low probability of occurrence for Respiratory disease could be gotten under the condition of proper humidity indoors, which was obtained by Absorption/Desorption of the porous building walls. Theoretical analysis, numerical simulation and testing study were combined to investigate the mechanism of heat and moisture transfers in a functional wall and its influence on environments in this project. The mechanism of heat and mass coupled transfer and influence of indoors envrionment was studied from microscopic, mesoscopic scales to macroscopic scale. On the basis of X-CT testing for relation between structural character and permeability of humidity control materials, the heat and moisture transer model in mesoscopic scale could be founded，and LBM was used to conjugatedly solve the model. Assisted by weak constraint condition, the multi-dimension model with dynamic sources in macroscopic scale could be solved by multiphysics conjuction of FEM. The heat and moisture transfer was analyzed and factors of transfer could be obtained. An optiminizing structure of building wall was analyzed and determined, in which heat and moisture transfer indoors could be satisfied. Then the couple relation between porous structure and heat and moisture coupled transfer could be received. The building walls with optimum structure testing by sensor of temperature and moisture sensors to obtain the transfer rule of heat and moisture, as well as air flew. Mathematical model could be corrected by the verification between testing and numerical simulation. The study could provide a theoretical and technology basis for the application of adjustiong request indoors by using building walls with passive control.

建筑墙体利用自身多孔吸放湿特性可有效调节室内的温湿度，降低夏季空调能耗并减少冬季呼吸疾病的发生几率。本项目采用理论分析，数值模拟与实验研究相结合的方式，从微观、介观及宏观尺度下研究建筑墙体内部热湿空气传递机理及其对室内环境的影响。借助于X-CT实验测试分析建筑墙体多孔结构特性与渗透率的关系，建立介观尺度下热湿耦合传递模型，利用LBM共轭求解方法进行数值求解；辅之以弱约束条件，利用有限元多物理场耦合方法对宏观尺度下的多维数学模型进行求解，分析热湿影响因素，并获得热湿空气耦合传递规律。探讨满足室内热湿传递需求的建筑墙体内部优化结构，确定墙体内部结构及热湿耦合特性与室内热湿环境的耦合关系。实验测试建筑墙体内部及环境可控小室内的温湿度变化，获得温湿度之间的耦合影响。通过实验测试与数值模型相互验证，修正数学模型，为采用被动式调节的建筑墙体的应用提供理论基础。

本项目以介观与宏观相结合的多尺度研究思路，采取理论分析、数值模拟和实验研究等方法，重点探讨墙体内部的湿分迁移过程及其对室内环境的热湿传递的影响规律。.在介观尺度下建立二维多孔墙体及室内空间的自然对流LBM模型，分析真实多孔墙体与室内的自然对流传热过程，在宏观尺度下对含湿墙体内部的空气流动及热湿传递机理进行理论分析，采用空气流动、传热和传湿守恒方程建立了宏观尺度下的墙体内部的热湿传递模型，利用集总参数法建立了室内的热湿传递模型，并在墙体与室内的交界面处采用边界条件互相耦合的方法，建立墙体与室内模型之间的关系，利用有限元法进行数值求解，获得墙体内部及室内的热湿传递规律。实验研究不同调湿材料墙体内部热湿传递特性及其对室内的影响特性。采用五种不同的材料做成墙体砌块，搭建温湿度测试小室，通过高精度温湿度传感器测试获得各种材料墙体内部及室内的热湿变化曲线，揭示了墙体的被动调湿性能对室内温湿度的影响。