Improving stability and heat transfer through a beam in a semi-circular absorber tube of a large-aperture trough solar concentrator

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Volume Title

A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Date

2021-08-01

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Language

en

Pages

11

Series

Energy, Volume 228

Abstract

The performance of a large-aperture high-concentration parabolic trough concentrator (PTC) with a semi-circular absorber tube (AT) can be improved through external fins. However, deformation of the AT at high temperatures is of major concern. Here, an innovative design using a beam at the bottom of the AT is proposed to reduce deflection and enhance heat transfer. Using numerical models, it was shown that the deflection could be reduced by 4% and thermal efficiency of the PTC by 0.2% using an optimal beam with 10 mm height. The average surface temperature of the AT surface was decreased by 1 K. The heat transfer enhancement was due to increased convective heat transfer area including no secondary flow. The increasing thermal resistance with increasing beam height offset the benefit so that the thermal efficiency improvement remains in practice constant over the studied range (10–30 mm) of beam heights. The beam can easily be incorporated into the AT without any material change needed.

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Funding Information: The work is supported by the National Natural Science Foundation of China (grant number 51736006 ) and the Aalto University . Publisher Copyright: © 2021 Elsevier Ltd Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

Keywords

Absorber tube deformation, Beam, Large-aperture parabolic trough concentrator, Semi-circular absorber tube, Thermal efficiency

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Citation

Gong, J H, Wang, J & Lund, P D 2021, ' Improving stability and heat transfer through a beam in a semi-circular absorber tube of a large-aperture trough solar concentrator ', Energy, vol. 228, 120614 . https://doi.org/10.1016/j.energy.2021.120614