Performance analysis of the stationary-reflector/tracking-absorber solar collector

Abstract

This is an analytical study of the performance of the stationary-reflector/tracking-absorber (SRTA) solar collector with tubular absorber. The mathematical treatment and the derived formulae are generalized for any rim angle and any absorber-to-reflector diameter ratio. The effects of these two parameters on the average concentration ratio are investigated. Different multi-reflection zones of the mirror are identified. Their contributions to the total concentrated power and the local concentration ratio, at different absorber points, are assessed. The concentration profile along the absorber is determined under different conditions. The influence of mirror reflectance on the flux density at different points is evaluated. The circumferentially-distorted concentration profile at times of oblique incidence is displayed. The absorber surface is divided into bright, faint and dim regions. A mathematical procedure is presented to contour these regions. Their occurrence and area growth are shown to be dependent on the rim angle and diameter ratio.