基于动态实验气候的建筑材料表面换热问题研究

Passive evaporative heat transfer phenomenon exists widely in building surface. Its heat transfer situation is closely related to many factors, including material internal heat-moisture transfer characteristics, material surface heat-moisture properties, climate environment elements, etc. It is a complex coupled heat-moisture transfer process, and has a strong difference with dry surface only coupling of radiation and convection heat transfer, as a result, building thermotechnical design results would be distorted according to the dry surface. Therefore, to correctly identify building materials surface heat transfer coefficients, and to explore the surface heat-moisture physical parameters test method, would be of great significance for indoor and outdoor thermal comfort, as well as urban high-temperature issue and heat island effect..The main contents of this project include: first, establish an effective test method on heat exchange capacities and heat transfer coefficients of building material's passive evaporative surface; second, systematically research and obtain significant influence factors and levels of typical building materials surface heat transfer coefficients during evaporation; third, discuss the variation and reasonable value of materials' external surface heat transfer coefficients.

建筑表面广泛存在被动蒸发换热现象。被动蒸发表面的换热与材料内部热湿迁移特性、材料表面热湿物性、气候环境要素等诸多因素密切相关，是一个复杂的热湿耦合换热过程，它与仅有辐射和对流耦合换热的干燥表面情况大为不同，致使目前按照表面干燥状态进行的建筑热工设计结果失真。因此，正确识别建筑材料表面换热系数，探求表面热湿物性基础参数的实验方法，对研究室内外热舒适性以及城市高温化及热岛效应等问题都有重要意义。.本项目的主要研究内容包括：1.确立建筑材料被动蒸发表面各换热量及换热系数的有效测试方法；2.系统研究并获取典型建筑材料在蒸发相变存在时表面换热系数的显著影响因素及水平；3.探讨材料外表面换热系数的变化规律及合理取值。

建筑表面广泛存在被动蒸发换热现象。被动蒸发表面的换热与材料内部热湿迁移特性、材料表面热湿物性、气候环境要素等诸多因素密切相关，是一个复杂的热湿耦合换热过程，它与仅有辐射和对流耦合换热的干燥情况大为不同，致使目前按照干燥状态进行的建筑热工设计结果失真。本课题以建筑类湿润多孔材料的动态换热问题为核心，在前期理论和实践基础上，发展了建筑材料和构件动态热湿传递性质的风洞测试方法，为正确识别湿润建筑类材料的热工参数提供了依据，并基于此探讨了5种典型城市下垫面材料被动蒸发换热状态下的热湿物性基础参数、被动蒸发影响因子及其权重、材料的气候适用性及蒸发换热特性等问题，研究成果对于室内外热舒适性改善和城市高温化及热岛效应等问题具有重要意义。