太阳光照吸收率对屋顶最优保温厚度的影响
|
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。
MATLAB matrix function is used to solve transient heat conduction hourly solar-air temperature with respect to so-lar 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 op-timized by minimizing the total cost of insulation and energy consumption by the present worth method. Life cycle saving and in-sulation payback period are calculated over lifetime of 20 years. The results indicate that roof surface temperature could be effec-tively 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 heat-ing 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.
MATLAB matrix function is used to solve transient heat conduction hourly solar-air temperature with respect to so-lar 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 op-timized by minimizing the total cost of insulation and energy consumption by the present worth method. Life cycle saving and in-sulation payback period are calculated over lifetime of 20 years. The results indicate that roof surface temperature could be effec-tively 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 heat-ing 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.
引文
[1]闫成文,姚健,林云.夏热冬冷地区基础住宅围护结构能耗比例研究[J].建筑技术,2006,37(10):773-774.
[2]钱晓倩,朱耀台.基于间歇式、分室用能特点下建筑耗能的基础研究[J].土木工程学报,2010(s2):392-399.
[3]Ozel M.Effect of wall orientation on the optimum insula tion thickness by using a dynamic method[J].Applied Energy,2011,88(7):2429-2435.
[4]Wati E,Meukam P,Nematchou A M.Influence of external shading on optimum insulation thickness of building walls in a tropical region[J].Applied Thermal Engineering,2015,90:754-762.
[5]曹国庆,涂光备,杨斌.水平遮阳方式在住宅建筑南窗遮阳应用上的探讨[J].太阳能学报,2006,27(1):96-99.
[6]白宪臣,陈天丽,张改新,等.既有建筑物平屋顶围护结构节能评估与改造[J].水电能源科学,2010,28(8):159-161.
[7]杨真静,唐鸣放,郑澎奎.绿化屋顶室内热环境研究[J].土木建筑与环境工程,2010,32(4):80-83.
[8]黄宝玉,李绍才,孙海龙,等.一种新型屋顶保温绿化植物卷材的研究[J].新型建筑材料,2014(6):96-99.
[9]王朋飞,崔展,柳靖.建筑围护结构热工特征对住区热环境影响的研究[J].建筑科学,2016,32(2):82-86.
[10]Duffie,John A,William A Beckman.Solar Engineering of Thermal Processes[M].Fourth Edition.Hoboken,New Jersey:John Wiley&Sons,2013.
[11]Ozel M,PIHTILI K.Optimum location and distribution of insulation layers on building walls with various orientations[J].Building and Environment,2007,42(8):3051-3059.
[12]Zhou S,Zhao J.Optimum combinations of building envelop energy-saving technologies for office buildings in different climatic regions of China[J].Energy and Buildings,2013,57(2):103-109.
[13]https://energyplus.net/weather-location/asia-wmo-region-2/CHN//CHN-Jiangsu.Nanjing.582380-CSWD.
[2]钱晓倩,朱耀台.基于间歇式、分室用能特点下建筑耗能的基础研究[J].土木工程学报,2010(s2):392-399.
[3]Ozel M.Effect of wall orientation on the optimum insula tion thickness by using a dynamic method[J].Applied Energy,2011,88(7):2429-2435.
[4]Wati E,Meukam P,Nematchou A M.Influence of external shading on optimum insulation thickness of building walls in a tropical region[J].Applied Thermal Engineering,2015,90:754-762.
[5]曹国庆,涂光备,杨斌.水平遮阳方式在住宅建筑南窗遮阳应用上的探讨[J].太阳能学报,2006,27(1):96-99.
[6]白宪臣,陈天丽,张改新,等.既有建筑物平屋顶围护结构节能评估与改造[J].水电能源科学,2010,28(8):159-161.
[7]杨真静,唐鸣放,郑澎奎.绿化屋顶室内热环境研究[J].土木建筑与环境工程,2010,32(4):80-83.
[8]黄宝玉,李绍才,孙海龙,等.一种新型屋顶保温绿化植物卷材的研究[J].新型建筑材料,2014(6):96-99.
[9]王朋飞,崔展,柳靖.建筑围护结构热工特征对住区热环境影响的研究[J].建筑科学,2016,32(2):82-86.
[10]Duffie,John A,William A Beckman.Solar Engineering of Thermal Processes[M].Fourth Edition.Hoboken,New Jersey:John Wiley&Sons,2013.
[11]Ozel M,PIHTILI K.Optimum location and distribution of insulation layers on building walls with various orientations[J].Building and Environment,2007,42(8):3051-3059.
[12]Zhou S,Zhao J.Optimum combinations of building envelop energy-saving technologies for office buildings in different climatic regions of China[J].Energy and Buildings,2013,57(2):103-109.
[13]https://energyplus.net/weather-location/asia-wmo-region-2/CHN//CHN-Jiangsu.Nanjing.582380-CSWD.