Measured effect of reflector augmentation of simple basin type pasive solar stills

Abstract

SYNOPSIS An investigation of a simple basin-type passive still, augmented by a concentrating reflector and dual effect still arrangement, has been conducted. Three systems were designed, fabricated and tested side-by-side in order to allow direct comparison of their experimental performance. A simple basin-type still showed the best aperture-based area output yield performance whilst a reflector-augmented still showed the best basin-based area output yield performance. Two stills augmented the basic still arrangement with an asymmetric inverted convection-suppression circular reflector design with a Compound Parabolic Concentrator. One collected both direct and indirect incident solar radiation and attained the highest operating temperatures and produced the most potable water, whilst the other collected indirect incident solar radiation only, coupled with a dual-effect still arrangement. The collection efficiency, still efficiency and quality of the water produced from the three solar distillation units is presented. The use of the dual effect still arrangement was not shown to significantly improve output. All systems improved the quality of the input water.