Abstract
This paper presents a new method for the optimisation of the mirror element spacing arrangement and operating temperature of linear Fresnel reflectors (LFR). The specific objective is to maximise available power output (i.e. exergy) and operational hours whilst minimising cost. The method is described in detail and compared to an existing design method prominent in the literature. Results are given in terms of the exergy per total mirror area (W/m2) and cost per exergy (US $/W). The new method is applied principally to the optimisation of an LFR in Gujarat, India, for which cost data have been gathered. It is recommended to use a spacing arrangement such that the onset of shadowing among mirror elements occurs at a transversal angle of 45°. This results in a cost per exergy of 2.3 $/W. Compared to the existing design approach, the exergy averaged over the year is increased by 9% to 50 W/m2 and an additional 122 h of operation per year are predicted. The ideal operating temperature at the surface of the absorber tubes is found to be 300 °C. It is concluded that the new method is an improvement over existing techniques and a significant tool for any future design work on LFR systems
Original language | English |
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Pages (from-to) | 147-156 |
Number of pages | 10 |
Journal | Solar energy |
Volume | 86 |
Issue number | 1 |
Early online date | 19 Oct 2011 |
DOIs | |
Publication status | Published - Jan 2012 |
Bibliographical note
NOTICE: this is the author’s version of a work that was accepted for publication in <Journal title>. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Davies, P & Nixon, J, 'Cost-exergy optimisation of linear Fresnel reflectors', Solar Energy, vol 86, no. 1 (2012) DOI http://dx.doi.org/10.1016/j.solener.2011.09.024Keywords
- solar thermal collector
- linear Fresnel reflector (LFR)
- linear Fresnel collector
- exergy
- CSP