The Reverse Flat Plate Collector: A Stationary, Nonevacuated, Low-Technology, Medium-Temperature Solar Collector

Abstract

The design, analysis, construction and testing of a novel solar collector is reported. The Reverse Flat Plate Collector (RFPC) is intended to be a stationary, nonevacuated, low-technology, medium temperature solar collector—a promising alternative for intermediate temperature thermal needs (100° C<T<200° C) in developing countries. The RFPC achieves high temperatures by convection suppression. The optical and thermal properties of this device are discussed for two different design options. Sensitivity studies to some of the most important system parameters are also presented. At collector fluid temperatures of 100–150 K above ambient, the yearly energy delivery of the RFPC is comparable to that of evacuated collectors. A prototype of this collector was designed, built and tested at the Joint Center for Energy Management at the University of Colorado. The experimental results accurately confirm the high collector stagnation temperatures predicted from theory and indicate that convective heat losses are indeed suppressed.