Performance of the ultimate trough® collector with molten salts as heat transfer fluid

Abstract

The present paper describes the ULTIMATE TROUGH® (UT) collector efficiency and solar field performance, when operated with molten salt as heat transfer fluid up to 550 °C. The analysis is based on the assessment of mirror shape evaluations performed at the DLR Quarz Center, on photogrammetry and deflectometry measurements performed at the UT prototype collector, and by ray-tracing, thermohydraulic and annual performance modeling. The optical analysis shows that the UT is expected to reach a reduced but still high intercept factor above 97% when installing a 70 mm diameter receiver. This diameter corresponds to a concentration factor of 100 and represents the optimum size for molten salt operation. This has been analyzed for a certain design point as well as for the annual electric output, taking into account optical and thermohydraulic aspects.