Theoretical performance analysis of new class of Fresnel concentrated solar thermal collector based on parabolic reflectors

Abstract

which are cheaper in comparison to glass reflectors. In this study, the effects of using parabolic reflectors instead of flat reflectors on Fresnel solar concentrator have been studied for the first time. For this new system by ray trace statistical method, local concentration ratio distribution has been determined. The new system is compared with linear Fresnel reflector (LFR). The effect of geometrical parameters, such as absorber height and reflectors width, on the concentration ratio is studied. The results have shown that using the parabolic reflectors with low curvature has a pronounced effect on the absorber pipe diameter. Comparison of the performance of linear and parabolic systems with identical parameters such as reflectors width, reflectors number and absorber pipe height showed that the absorber tube diameter in a parabolic system is smaller than the absorber tube diameter in a linear system, thus decreased rate of heat loss from the pipe surface. Comparison of the two systems under equal solar energy radiation and absorber pipe diameter showed that in parabolic system wider reflectors can be used, thus reduced number of reflectors and simpler control system.