太阳光照吸收率对屋顶最优保温厚度的影响

2.华融开放健康城置业（武汉）有限公司，湖北 武汉  430000；3.湖南大学，湖南 长沙  410082]

    摘要：对保温材料太阳光照吸收率从0~1变化，采用MATLAB矩阵函数求解瞬态热传导逐时太阳-空气温度。根据逐时太阳-空气温度计算南京办公建筑屋顶XPS保温全年采暖和制冷负荷。基于现值系数最大程度减少保温总成本和加热冷却能耗得到最优保温厚度。通过20年寿命周期计算，得出采用最优保温厚度节省经济成本和保温投资回收期。结果表明，减小太阳光照吸收率可有效降低屋顶外表面温度，随着太阳光照吸收率的减小，全年采暖热负荷线性增加，而空调冷负荷线性降低，冷负荷减小速率大于热负荷增加速率。最优保温厚度为6.3~7.1 cm。太阳光照吸收率对最优保温厚度影响不大，而对全年冷热负荷以及寿命周期节省经济成本影响较大。

    关键词：太阳光照吸收率；太阳-空气温度；冷热负荷；最优保温厚度；寿命周期节约

    中图分类号：TU55        文献标识码：A        文章编号：1001-702X（2018）05-0131-05

 

Effect of solar absorptance on optimum insulation thickness of roof  

LI Fengcui1，XU Xiang2，FANG Aimin3

（1.School of Energy and Building Environment Engineering，Henan University of Urban Construction，Pingdingshan 467036，China；

2.Huarong Open Health City Real Estate（Wuhan） Co. Ltd.，Wuhan 430000，China；3.Hunan University，Changsha 410082，China）

    Abstract：MATLAB matrix function is used to solve transient heat conduction hourly solar-air temperature with respect to solar absorptance of insulation material varying from 0 to 1. For XPS insulation material，the annual heating and cooling transmission load are calculated according to the hourly solar-air temperature for office building located in Nanjing. Insulation thickness is optimized by minimizing the total cost of insulation and energy consumption by the present worth method. Life cycle saving and insulation payback period are calculated over lifetime of 20 years. The results indicate that roof surface temperature could be effectively reduced by decreasing the solar absorptance. Annual heating load increased linearly with the decrease of solar absorptance while the annual cooling load decreased linearly with it. The decrease rate of cooling load is larger than the increase rate of heating load. Optimum insulation thickness is between 6.3~7.1 cm. Solar absorptance has a small effect on the optimum insulation thickness while it has a great influence on the annual heating and cooling transmission load and life cycle saving.

    Key words：solar absorptance，solar-air temperature，heating and cooling load，optimum insulation thickness，life cycle saving