Experimental investigation of absorbed flux circumferential distribution of an absorber with U-pipe tube exchanger for Parabolic Trough Collectors

Abstract

In this work, an experimental study on a parabolic trough collector with U shaped exchanger has been investigated for normal incidence radiation. This study was focused on the effects of the focal length (as well as the rim angle) and the diameter of the absorber on the flux circumferential distribution. Thus, the heat losses related to the dimensioning of the U-pipe position were studied. The inlet, outlet, absorber and ambient temperatures as well as instantaneous beam normal radiation were reported. Our analysis concerned the concentrated solar flux distribution on the circumferential absorber for different rim angles and diameters, and it relation with the position of U-pipe. We noticed a higher thermal efficiency of about 0.4 of the Parabolic Trough Collector for the focal length 0.19 m (parallel position of exchanger). These first results remain enough interesting to investigate advanced Parabolic Trough Collector prototype.