全玻璃真空管太阳能热水器的季节性能

采用商业软件Fluent建立了全玻璃真空集太阳能热水器流场和温度场的计算模型,并引入使用者定义函数(UDF)分析了全玻璃真空管太阳能热水器四季的性能.考虑了太阳的日运动和季节性运动对太阳入射角和投射在真空管集热器上的太阳辐射量的影响.通过与实验对比,发现数值模拟结果与实验结果具有较好的拟合性.结果表明:水温夏季升高速率快,冬季速率慢,同时在春季、夏季和秋季,热水输出足以满足生活用热水的需求.该结果可作为继续研究设计冬季里产生较高温度热水的新系统的基础.

Seasonal Performance of Water-in-Glass Evacuated Tubes

A computational model of water-in-glass evacuated solar heater was developed through the commercial software Fluent, and the UDF was introduced to analyze the performance of the heater with all the four seasons considered. In the analysis the effects of the apparent daily/seasonal movement of the sun on the angle of incidence and of the quantity of radiation on the evacuated tube collector were both taken into account. Compared with the experiment results, the numerical simulation results showed the goodness of fit. A conclusion was therefore drawn that the water temperature increases quickly in summer but slowly in winter and that the hot water supplied in this way can meet fully the household requirements of hot water in summer, spring or autumn. A foundation is then laid down for further study to design a new system for supplying the water at higher temperatures even if in winter.