Abstract
The heat losses from concentrating solar collectors can be reduced by thermally isolating the absorber with an optimal air gap between the absorber and the glass cover. However, in reflectors attempting to attain maximum optical concentration, some of the reflected rays will escape through this gap, resulting in increased losses. A concentrator was fabricated and tested with a plane tubular absorber, the results having been reported earlier. The present paper describes a design procedure for an absorber which avoids the ‘optical’ losses through the air gap. The results for the modified absorber are compared with those for the plane tubular one. The intercept factor is improved from 0·8 to 0·92. The surface area of the modified absorber is about 9 % larger than that of the plane tubular one, but the shape is such that the overall heat loss factor is much lower. As a result, the total heat loss for the modified absorber at a temperature 100° C above ambient is only 0·2 % higher than that of the plane tubular one. The improved performance curves are shown. The absorber design is also acceptable from the point of view of strengths of the components involved.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.