夏热冬冷地区居住建筑外墙外保温的反节能现象

Anti-insulation behavior for exterior wall external insulation on residential buildings in hot summer and cold winter zone

针对夏热冬冷地区居住建筑现行节能设计标准中空调系统部分设计工况与该地区实际情况存在一定出入的问题,以杭州市为例,采用EnergyPlus能耗模拟软件模拟分析该地区居住建筑不同用能工况下外墙外保温的节能效果.结果显示,在标准规定的连续用能方式下,外墙外保温节能效果良好;而在间歇用能方式下,外墙外保温会增加全年冷负荷.以1971—2000年的日值气象数据为基础,采用五日滑动平均法,得出实际杭州市的采暖及空调期推荐值.在采用新的采暖、空调期后,外墙外保温夏季反节能现象对全年能耗的影响更加显著,全年节能率明显减小.进一步研究表明,对于窗墙比及制冷设定温度而言,均存在一系列的外保温反节能临界值(窗墙比为0.3,制冷设定温度为26℃),低于此临界值时外保温节能,高于此临界值时反节能.

The EnergyPlus simulation software was employed to analyze the energy saving effect of exterior wall external insulation in residential building of the hot summer and cold winter zone.Hangzhou was taken for an example to address the problem of the discrepancy between the actual air conditioning（AC）working conditions and design conditions in standards for residential building energy efficiency in this region.Results show that under the standard way of continuous AC operation method,exterior insulation has good energy saving effect;however,under intermittent AC operation method,external insulation can increase the annual cooling load.Based on daily meteorological data from 1971 to 2000,the five days moving average method was adopted to obtain the recommended value of heating and cooling period,which is more accordant with the actual situation of Hangzhou.After using the new heating and cooling period,the influence of anti-insulation behavior for exterior insulation on annual energy consumption is more significant;the annual energy saving rate significantly reduced.Further research shows that for the window to wall ratio（WWR）and cooling set temperature,there are a series of critical value for antiinsulation behavior in summer cooling（0.3for WWR and 26℃for cooling set temperature）.When WWR and cooling set temperature are lower than the critical value,external insulation saves energy;when WWR and cooling set temperature are higher than the critical value,total energy consumption increases.