太阳辐射吸收系数对建筑物全年空调能耗的影响

摘要

以上海地区的建筑围护结构传热过程为研究背景,在分析太阳辐射作用下围护结构热平衡关系的基础上,采用数值模拟方法,讨论了太阳辐射吸收系数对4种不同朝向围护结构冬季和夏季外表面温度和太阳辐射全天净得热量的影响.结果表明:减小屋顶、东墙和西墙的太阳辐射吸收系数有利于降低建筑夏季供冷能耗,提高南墙外表面吸收系数能明显降低冬季供暖能耗;南墙采用吸收系数较高的粉刷材料将有利于降低供热供冷总能耗和外饰面造价,除南墙外其他朝向外表面应选用吸收系数较低的反射隔热涂料,且其经济性与建筑高度和窗墙比有关.%Based on energy balance of building exterior surfaces with different solar absorption coefficients,the heat transfer processes of building envelopes in the Shanghai area are studied by numerical simulations.The time series of the temperature of building exterior surfaces with four different orientations and the daily net heat gain due to solar radiation of the building envelopes are analyzed on winter and summer solstices by using the simulation data.The results show that the reducing of solar radiation absorption coefficients of the roof,eastern and western exterior surfaces are beneficial to conserve the summer cooling energy consumption.In contrast,the absorption coefficients of the exterior surface of southern wall can obviously reduce energy consumption in winter.Moreover,taking aim at reducing the annual energy consumption and the annual cost of coating,the exterior surface of southern wall should employ the common painting with higher absorption coefficient,while the best option of solar radiation absorption coefficient for the other facades are solar reflective coatings with lower absorption coefficient,and its economic effectiveness is determined by the height and window-to-wall ratios of building.