特朗伯集热墙耦合传热机理和动态传热特性研究

Trombe Wall is taken as a kind of important passive solar building energy-saving technology, whose dynamic coupling heat transfer process includes important radiation heat transfer problems of physical mechanism, and these problems affact the thermal energy-saving properties of Trombe Wall. Extensive numerical and experimental studies on heat transfer characteristics and improving technology of Trombe Wall were carried out by home and abroad investigators. But there exist several deficiencies expecially in numerical simulation. Firstly, on coupling thermal boundary surfaces, absorbed solar and long-wave heat radiation is taken as heat flux boundary condition instead of volume heat source. The treatment as volume heat source is in according with the actual physical process. Secondly, long-wave transparent radiation though glass cover-plate of Trombe Wall should be considered. Two papers about long-wave transparent radiation characteristics of single glass and double hollow glazing have been published in international journal “Energy and Buildings” by us. The research results can help the current project. Thirdly, the study on three-dimensional periodical unsteaty coupling heat transfer simulation and dynamic heat transfer characteristics of Trombe Wall is weak and should be enhanced. Based on above analysis and present work, equipped with theoretical analysis, numerical calculation and experimental methods, this project tries to study four main contents: (1) under conditions of considering solar radiation heat and long-wave radiation heat absorbed by glass cover-plate and heavy wall surface as volume heat source, and of considering long-wave transparent radiation action of glass cover-plate, setting up three-dimensional steady and periodic unsteady coupling heat transfer model of Trombe Wall; (2) developing method of embeding the numerical algorithm for radiation heat transfer based on Monte Carlo Method into flow model; (3) using numerical and experimental method to confirm the transfer thickness of volume heat source after non metal solid materials surface absorbing radiation heat; (4) taking use of the above numerical model to analyzing dynamic coupling heat transfer mechanism and characteristics of Trombe Wall, and validating them by experiment, at last presenting optimum design and using strategy of Trombe Wall. The study results of this project have important academic significance and applied values not only in enhancing the knowledge of transfer mechanism after non metal solid materials surface absorbing radiation heat and of long-wave transparent radiation rules for composite heat transfer system including glass, but also in indicating deeply dynamic coupling heat transfer characteristics of Trombe Wall in order to provide reliable basis for it’s thermal energy-saving optimization design.

特朗伯集热墙作为一种重要的被动式太阳能建筑节能技术，其动态耦合传热过程包含着重要的辐射传热物理问题，这些问题影响着其热工节能特性。基于现有研究基础，项目采用理论分析、数值分析和实验相结合的方法，开展四方面研究工作：（1）将玻璃盖板和重质墙体表面吸收太阳热辐射及长波热辐射后作为体积内热源考虑，以及考虑玻璃的长波热辐射透射作用的条件下，建立特朗伯集热墙三维稳态和周期性非稳态耦合传热模型并求解；（2）发展流动传热模型中嵌入蒙特卡洛辐射传热数值算法的方法；（3）结合实验确定非金属固体材料表面吸收辐射热流后作为体积内热源的分布厚度；（4）利用上述模型计算分析揭示特朗伯集热墙动态耦合传热机理与特性，并进行实验验证，最终提出特朗伯集热墙的优化设计与使用策略。项目研究结果不但可加强对固体表面吸收热辐射后在内部分布传递机理和有玻璃参与构成的复合传热系统的长波透射辐射传热规律的认识，还可以深刻揭示特朗伯集热墙的动态耦合传热特性，为其热工节能优化设计提供可靠依据，具有较大的学术意义和较高的应用价值。

本项目通过理论与数值分析和实验相结合的方法建立了特朗伯集热墙系统的三维耦合传热模型，分析揭示了特朗伯集热墙的耦合传热机理和动态传热特性，提出优化设计策略。依据项目计划书的研究内容主要获得以下研究结论和成果：. （1）将南向特朗伯集热墙和毗邻房间作为整体构建计算区域模型，采用有限容积法的数值计算方法构建直角坐标系下三维正交网格系统，包括特朗伯集热墙组件、室内空气、内墙和楼板。全场耦合计算，计算区域建立导热及对流的耦合传热模型，空气夹层、集热墙上下通风孔、室内空气区域采用自然对流条件低Re数k-ε模型。流体区域求解速度与压力耦合方程采用SIMPLE算法，固体区域的导热扩散方程求解采用交替方向隐式算法。初步考虑了网络法和蒙特卡洛法数值计算表面间辐射传热嵌入流动传热模型。. （2）采用集总参数法建模分析获得特朗伯集热墙系统中空玻璃盖板的玻璃长波辐射透射率与中空玻璃内外表面综合换热系数之间的关系。相比不考虑玻璃长波辐射透射率τg=0，当τg=0.1时，夏季中空玻璃内、外表面综合换热系数均增大2.3W/(m2 K)；冬季中空玻璃内表面综合换热系数增大1.1W/(m2 K)，外表面增大3.7W/(m2 K)。玻璃的长波透射辐射作用等效转化为中空玻璃盖板计算区域边界条件参数：内外表面综合换热系数。. （3）数值和实验研究了特朗伯集热墙的动态传热特性，优化集热墙结构参数设计策略。其中数值研究表明窄夹层特朗伯集热墙节省空间、对流供热效率较低，宽夹层附加阳光间式特朗伯集热墙对流供热效率更高、并形成公共活动空间；实验研究表明被测实验室的特朗伯集热墙冬季日平均热效率可达18.4%，但相比居住建筑，公共建筑空间更大，集热墙通风口面积应增大。. 项目累计在国内外发表论文5篇，其中SCI、EI收录2篇，在投SCI论文1篇；授权发明专利1项；获得甘肃省高等学校科研优秀成果三等奖1项；培养毕业硕士研究生3名，在读硕士研究生2名。