夏热冬冷地区太阳辐射对建筑围护结构能耗影响分析

为解决夏热冬冷地区建筑热工设计时，建筑物夏季要“挡”太阳辐射、冬季要“用”太阳辐射这一看似矛盾的问题，采用理论推导与模拟计算及实验验证的方法，以夏热冬冷气候区内典型建筑为研究对象，分析围护结构(墙体与屋顶)在不同设计参数时，其内外表面温度变化及建筑冷热负荷需求特性.研究结果表明：随着围护结构外表面材料太阳辐射吸收系数由0.9减小到0.3，围护结构外表面温度明显降低，其中外表面最高温度最大降幅20.2 ℃(屋顶)，平均温度最大降幅6.9 ℃(屋顶)，而内表面温度降幅不大；降低太阳辐射吸收系数，可以明显降低建筑夏季冷负荷需求，对冬季热负荷影响甚微；增大围护结构(墙体与屋顶)热阻能够降低建筑冬季热负荷需求，并且热阻与节能量近似呈线性关系，但其对降低夏季冷负荷的效果不如降低冬季热负荷明显，并且有“反节能”风险.该研究可为夏热冬冷气候区建筑围护结构的优化设计，解决夏季隔热及全年综合降低空调能耗问题提供参考.
The contradictory problem that “blocking” the solar radiation in summer and “receiving” the solar radiation in winter for buildings thermal design should be considered in hot summer and cold winter zone in China. In this paper, the typical building in hot summer and cold winter zone was analyzed by theoretical deduction, simulation calculation and experiment validation in order to obtain the effect of different envelope design parameters on internal and external surface temperature changes and heat/cold load demand. The results show that when the solar radiation absorption coefficient decreases from 0.9 to 0.3, the external surface temperatures of envelopes are reduced significantly, and the largest declines of the maximum temperature and the average temperature are 20.2 degrees and 6.9 degrees (roofs), respectively, but there is no change of the internal surface temperatures. By reducing the solar radiation absorption coefficient, building cooling load demand in summer can be decreased significantly, and nearly no effect on heating load in winter. The building heating load in winter can be reduced by increasing the thermal resistance of walls and roofs, and the thermal resistance and energy savings are approximately linear, but the effect of the thermal resistance on the building cooling load is less than building heating load, and there are “anti-saving” risks. This study is valuable, and will be helpful to design building envelopes and heat insulation so as to realize energy consumption reduction of the air conditioning in the whole year in hot summer and cold winter zone.