A solar concentrator design for uniform flux on a flat receiver

Abstract

The paper presents a new design of solar concentrator (reflector) capable of concentrating a collimated beam of light of uniform flux onto a flat receiver to obtain a uniform flux distribution. The main advantage of this design is that the reflector consists of a series of flat panels of different sizes, enabling the use of commercially available plane mirrors. Another feature of this design is that the uniform flux distribution on the receiver is independent of the reflectivity, transmissivity and absorptivity variation with the incident angle of the incoming solar flux. Four different concentrator-receiver geometries have been analysed to determine the slope and width of the various reflector panels, concentration ratio and concentrator surface are requirements. The configuration with the back lit vertical receiver was found to be the best out of these four cases. The effect of the finite size of the sun on the flux distribution of the receiver is also included. A concentrator of this design, with back lit vertical receiver, was fabricated. Measurement of the flux on its receiver indicate a quite uniform flux distribution in about 80% of the area.