Performance Evaluation of a Helical Coil Heat Exchanger Working under Supercritical Conditions in a Solar Organic Rankine Cycle Installation

Energies

Alihan Kaya¹  Steven Lecompte¹  Michel De Paepe¹  Henk Huisseune¹  Marija Lazova¹  George Kosmadakis² 

[1] Department of Flow, Heat and Combustion Mechanics, Ghent University, Sint-Pietersnieuwstraat 41, Ghent 9000, Belgium;Department of Natural Resources and Agricultural Engineering, Agricultural University of Athens, Iera Odos street 75, Athens 11855, Greece;

关键词: organic Rankine cycle (ORC);    supercritical heat transfer;    heat exchanger design;    concentrated PV collectors;    helical coil heat exchanger;   

DOI  :  10.3390/en9060432

来源: DOAJ

【 摘 要 】

Worldwide interest in low grade heat valorization using organic Rankine cycle (ORC) technologies has increased significantly. A new small-scale ORC with a net capacity of 3 kW was efficiently integrated with a concentrated solar power technology for electricity generation. The excess heat source from Photovoltaic (PV) collectors with a maximum temperature of 100 °C was utilized through a supercritical heat exchanger that uses R-404A as working medium. By ensuring supercritical heat transfer leads to a better thermal match in the heat exchanger and improved overall cycle efficiency. A helical coil heat exchanger was designed by using heat transfer correlations from the literature. These heat transfer correlations were derived for different conditions than ORCs and their estimated uncertainty is ~20%. In order to account for the heat transfer correlation uncertainties this component was oversized by 20%. Next, a prototype was built and installed in an integrated concentrated photovoltaic/thermal (CPV/T)/Rankine system. The results from the measurements show that for better estimation of the sizing of the heat exchanger a more accurate correlation is required in order to design an optimal configuration and thus employ cheaper components.

【 授权许可】

Unknown