Design and Optical Modeling of a Low-Profile Stationary Concentrating Solar Collector for Medium Temperature Heat Supply

Abstract

Imaging type concentrating solar collectors need very accurate and continuous tracking mechanisms to efficiently collect and supply solar thermal energy in medium temperature range. Non-imaging nature of compound parabolic concentrators (CPC) enable these devices to concentrate incident radiation without the essential need of continuously tracking the source. CPC based solar collectors have great potential to supply solar thermal energy for numerous industrial applications especially operating in the medium temperature range. The choice of a CPC collector design varies depending on various aspects such as nature of intended application, operating temperature range, location and local environmental conditions. The present paper describes the design and optical modelling of a low concentration (CR<2) symmetric 2-D CPC collector for medium temperature heat supply. Ray tracing technique was used to evaluate the optical performance of double parabolic concentrating trough and CPC trough with Vcavity at the bottom. The gap losses were significantly reduced by making V-shaped cavity at the bottom.