太阳能富集地区建筑的等效体形系数*
Equivalent shape factor of buildings in solar-enriched areas
摘要:
分析了体形系数用于只需供暖的太阳能富集地区建筑围护结构热工设计时存在的问题,提出了等效体形系数的概念,并给出了其物理意义与计算方法。研究结果表明:透明围护结构在一定朝向范围内,太阳辐射得热大于热损失,并非失热构件;等效体形系数应表述为建筑物与室外空气直接接触的外表面积扣除有效得热面对应的等效面积后与其所包围的体积的比值;与体形系数相比,等效体形系数与外围护结构单位体积耗热量指标的相关性较高,相关系数大于0.90;采用等效体形系数代替传统体形系数指导建筑围护结构热工设计,可起到引导设计师优化建筑朝向、增加得热面窗墙面积比的作用。
Abstract:
Analyses the problems existing in the building envelope thermal performance design in solar-enriched areas with heating only. Proposes the concept of equivalent shape factor, and gives its physical meaning and calculation method. The research results show that the solar heat gain of a transparent envelope is greater than the heat loss during a certain orientation scope, which makes it become a heat gain surface. The equivalent shape factor should be expressed as the external surface area of building directly in contact with outdoor air minus the equivalent area corresponding to effective heat gain surface divided by the volume enclosed. Compared with the shape factor, the equivalent shape factor has a high degree correlation with the heat loss per unit volume, and the R square can reach above 0.90. Using the equivalent shape factor substituted for the shape factor as the basis for envelope thermal performance design of passive solar building can lead the designer to optimize building orientation and adopt larger window to wall ratio.
Keywords:shapefactor,equivalentshapefactor,effectiveheatgainsurface,correlationanalysis,buildingthermalperformancedesign