ارزیابی تئوری و تجربی عملکرد کلکتور تحت خلأ دارای لوله‌های حرارتی در سنندج

In this study, an experimental system that includes evacuated tube heat pipe solar collector, is constructed and tested under weather conditions of Sanandaj in 21 August, 30 August and 7 September. Then a mathematical model, based on energy and exergy balance equations have been developed and the theoretical results were compared with experimental ones. The obtained results showed that the optimum number of vacuum tubes in weather conditions of Sanandaj is equal to 15. In the final hours of the day exergic efficiency is high. The effect of collector fluid mass rate on its efficiency is little at the beginning hours of the day and gradually increases over time. Also, the effect of this parameter is much more in lower values. Finally, the results of mathematical model developed to simulate the performance of evacuated tube heat pipe solar collector were compared experimental results and a good agreement was observed in terms of standard error and maximum relative error.