Design and Operational Influences on Thermal Performance of “Solaris” Solar Collector

Abstract

Thermal performance characteristics of the “Solaris” water-trickle collector have been experimentally determined using the University of Virginia Solar Energy Research Facility. A theoretical model of the collector has also been used to examine the thermal performance of the collector. The model and experimental measurements were used to determine the sensitivity of the collector’s performance to such variables as ambient temperature, mass flow rate, insolation rate, wind, and glazing cleanliness. It was found that ambient temperature and wind are the two major variables which influence collector performance. Experimental measurements and the model also were used to demonstrate how design changes, such as glazing spacing, glazing material, double glazing, and condensate suppression influence and the performance of the water-trickle collector. Various glazing materials and double glazing were found to greatly change the collector’s performance. Changes in performance are reported in terms of the performance parameters FR , (τα)e and UL and graphically illustrated with plots of collection efficiency versus (Ti − Ta )/I.