Beam-down linear Fresnel reflector: BDLFR

Abstract

This paper presents a novel linear solar concentrating system named BDLFR, acronym of Beam-Down Linear Fresnel Reflector. A BDLFR system consists of a primary LFR array reflecting sunlight into a secondary hyperbolic -or elliptic- cylinder mirror that beams-downs reflected rays to its secondary focal line at ground level, where the receiver is placed. A model based on vector notation -and validated against SolTrace- predicts the optical behavior of BDLFR and generates layouts to avoid blockings. The edge ray approach is utilized to determine receiver aperture widths. As a function of beam-down curvature ratio, the BDLFR configurations that maximize solar collection are found out. Concentration ratios about 80 are reached with a tertiary re-concentrator (CPC) coupled to the receiver aperture.