Optical performance of CPCs for concentrating solar radiation on flat receivers with a restricted incidence angle

Yamei Yu, Nianyong Liu and Runsheng Tang

Renewable Energy, 2014, vol. 62, issue C, 679-688

Abstract: In some applications of compound parabolic concentrators (CPCs), the incidence angle of solar rays on the absorber is restricted and must be less than a specified value (θe) for efficient energy conversion or transfer. For a flat receiver with a restricted incidence angle (RWARIA, in short), two ideal concentrators designed based on one-sided flat absorber can be employed for radiation concentration: one is the CPC without exit angle restriction (CPC-1), and another is the CPC with a restricted exit angle (CPC-2). In this work, the angular dependence of optical efficiency factor of both CPC-1 and CPC-2 for concentrating radiation on the RWARIA was derived, and a mathematical procedure to estimate daily radiation accepted by the RWARIA by using east-west oriented CPC-1 and CPC-2 was suggested based on the solar geometry and monthly horizontal radiation. Results by numerical calculations show that, for fixed full CPC-1 and CPC-2 with identical acceptance half-angle (θa), the CPC-2 is slightly more efficient than CPC-1 for concentration radiation on the RWARIA except periods of about 30 days before and after both equinoxes; whereas for fixed truncated CPC-1 and CPC-2 with identical geometric concentration factor (Ct) and θa, the CPC-2 is always more efficient. Results also indicate that, for the case of the tilt-angle of the aperture of CPCs being yearly adjusted four times at three tilts, full CPC-2 is less but truncated CPC-2 is more efficient than CPC-1 for concentrating radiation. In practical applications, CPCs are usually truncated due to less efficient of top portion of a CPC reflector for radiation concentration and less reflector material use, therefore, the CPC-2 is more favorable and advisable for concentrating radiation on the RWARIA.

Keywords: Compound parabolic concentrator; Flat receiver with a restricted incidence angle; Optical efficiency factor; Optical performance (search for similar items in EconPapers)
Date: 2014
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (4)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0960148113004400
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:renene:v:62:y:2014:i:c:p:679-688

DOI: 10.1016/j.renene.2013.08.038

Access Statistics for this article

Renewable Energy is currently edited by Soteris A. Kalogirou and Paul Christodoulides

More articles in Renewable Energy from Elsevier
Bibliographic data for series maintained by Catherine Liu ().