一种计算太阳能集热器长期性能的新方法

A new method for calculating long-term performance of solar collector

基于大气层透射率时角函数和集热器的稳态模型,提出一种计算集热器长期性能的新方法——日周期法.该方法只需要日均气象参数,可得到与瞬时系统模拟软件计算结果相同的日总集热量.以兰州地区为例,采用数学拟合的方法得到大气层透射率的时角函数.根据日周期法,分析知全年、夏季和冬季的集热器最佳放置倾角分别为25°、11°、49°;计算了平板集热器在全年最佳倾角下的日总集热量,与瞬时系统模拟软件的计算结果相同,验证了模型的可靠性;最后分析了两种不同性能平板型集热器在兰州地区不同时段的平均效率.

Based on the hour angle function of solar radiation transmittance through atmosphere and steady-state model of solar collector, a new method-daily periodic method is proposed for calculating long- term performance of solar collector. Using this method only average daily meteorological parameters are needed to the daily amount of heat collection, which is identical to that obtained by software of transient system simulatiorL Taking Lanzhou region as an example, the atmosphere transmittance hour angle func- tion is obtained by using polynomial fitting method. It is known by analysis with the daily periodic method that the optimal tilt angle of solar collector in whole year, summertime, and wintertime of collector will be 25°, 11° and 49°, respectively. The annual daily amount of heat collection of plate solar collector with opti- mal tilt angle is calculated with daily periodic method. The result is consistent with that obtained by tran- sient system simulation soft ware. Finally, the average efficiency of two plate solar collector with different performance in Lanzhou region in different time is analyzed.