Measurement of radiation distribution on the absorber in an asymmetric CPC collector
2004 (English)In: Solar Energy, ISSN 0038-092X, Vol. 76, no 1-3, 199-206 p.Article in journal (Refereed) Published
A method to estimate the annual collected energy and the annual average optical efficiency factor is suggested. The radiation distribution on the absorber of an asymmetric CPC collector with a flat bi-facial absorber is measured for three different absorber mounting angles using a photo diode. The annual optical efficiency factors and a relative measure of the annual collected energy are determined for collectors with the absorber fin thickness 0.5 and 1 mm, and for a collector with a teflon convection suppression film mounted around the absorber. With the local optical efficiency factors and the annual incident solar energy distribution considered, the analysis indicates that the energy gain for a mounting angle of 20° is higher than for a collector with 65° absorber mounting angle. The annual collected energy is increased with 6–8% if the absorber fin thickness is increased from 0.5 to 1 mm. The annual average optical efficiency factor is relatively independent of the absorber mounting angle. It was found to be 0.87–0.88 for a collector with a 0.5 mm thick absorber fin and 0.92 for a collector with a 1 mm thick absorber fin or for a collector with 0.5 mm thick absorber fin with a teflon convection suppression film added. The low annual average optical efficiency factor is not caused by the uneven irradiance distribution but by the relatively high UL-values.
Place, publisher, year, edition, pages
2004. Vol. 76, no 1-3, 199-206 p.
IdentifiersURN: urn:nbn:se:uu:diva-89751DOI: 10.1016/j.solener.2003.08.024OAI: oai:DiVA.org:uu-89751DiVA: diva2:161484
Solar World Congress 2001