Design, Evaluation, and Testing of a Moderately Concentrating, Nontracking Solar Energy Collector

The thermal performance of a moderately concentrating, nontracking, trough-like solar energy collector is predicted based on a series of experimental evaluations of its components. Four reflector designs were constructed and tested. Two were one-facet side wall (reflector) designs; two were two-facet designs. Six simple tubular, nonevacuated receiver designs were tested. A collector utilizing one of the reflector designs, geometric concentration ratio of 2.6, and one of the receiver designs was constructed and tested. The predicted performance (an effective overall heat loss coefficient of 4.6 W/m²–°C, an optical efficiency of 0.71 and a heat recovery factor of 0.95) closely approximated the actual thermal performance of the collector. The component evaluations are discussed in such detail that the analysis could easily be extended to other designs by the reader.