The Impact of the Parabolic Dish Concentrator on the Wind Induced Heat Loss From Its Receiver

Date
2017-07-15
Authors
Uzair, M
Anderson, TN
Nates, RJ
Supervisor
Item type
Journal Article
Degree name
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract

Abstract To achieve higher operating temperatures, power output and system efficiencies in parabolic dish cavity receivers, larger dish sizes and structures are used to increase the concentration ratio. This increases capital investment and installation costs, which in turn places a much stronger emphasis on accurately predicting the performance of the system and the heat loss from it. Numerous studies have investigated the natural convection heat losses from cavity receivers, and some have examined a cavity exposed to wind. However, the effect of the dish on the wind flow and subsequently the heat loss from the receiver has not been widely considered. In this work, computational fluid dynamics was used to model the flow of air around a parabolic dish concentrator operating at varying angles of operation. The flow fields were validated using wind tunnel testing and published data regarding the aerodynamic characteristics of parabolic dishes. The results showed that the orientation of the dish has a significant effect on the flow structure near the receiver. Subsequently, using the validated method, the convective heat loss from the receiver of a large parabolic dish system was determined for a range of operating conditions. The results support the assertion that the flow characteristics near the cavity receiver aperture depend strongly on the orientation of the dish structure. This resulted in the calculated heat loss being up to 40% lower than previous studies where the presence of the dish was included. As such, the wind flow around the dish needs to be accounted for when analyzing the performance of parabolic dish systems to avoid an overly conservative and hence more expensive design.

Description
Keywords
Parabolic dish , Heat loss , Wind , CSP
Source
Solar Energy, 151, 95-101.
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Copyright © 2017 Elsevier Ltd. All rights reserved. This is the author’s version of a work that was accepted for publication in (see Citation). 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. The definitive version was published in (see Citation). The original publication is available at (see Publisher's Version).