Thermal Modeling and Performance Analysis of U-Tube Evacuated Solar Collector using CO2

(Pages 69-77)
Onder Kizilkan1,* and Hiroshi Yamaguchi2

1Department of Mechanical Engineering, Faculty of Technology, Isparta University of Applied Sciences, 32200, Isparta, Turkey
2Department of Mechanical Engineering, Doshisha University, Kyo-Tanabeshi, Kyoto 610-0321, Japan

DOI: http://dx.doi.org/10.15377/2410-2199.2019.06.8


This study deals with the thermal modeling of U-tube evacuated solar collectors to investigate the heat transfer and performance characteristics. The U-tube evacuated solar collectors are integrated into solar-assisted new
generation experimental organic Rankine cycle working with environmentally friendly supercritical CO2. For the modeling, one-dimensional heat transfer analysis is applied to the U-tube collectors for determining the heat transfer characteristics of the collectors as well as the CO2 exit temperature from the collectors for the steady heat transfer process. Additionally, heat loss coefficient and overall heat transfer coefficients are determined for the experimental U-tube collectors. The obtained results are also compared with the results of the experimental study.

Keywords:Solar energy, carbon dioxide, Rankine cycle; U-tube evacuated solar collector.