Comparative study of heat transfer enhancement using different fins in semi-circular absorber tube for large-aperture trough solar concentrator

An improved evacuated absorber tube (AT) design consisting of a semi-circular tube is proposed for large-aperture parabolic trough concentrator. The absorber tube also contains a flat-plate radiation shield in the vacuum part of the tube in the glass cover. To enhance the heat transfer in the AT, different fins geometries added to the bottom of the AT were analyzed here. Compared to an AT without fins, the thermal efficiency of the tube could be increased from 75.7% to 76.9% with a short and thick fin and to 77.3% with a long and thin fin in the flow velocity range of 0.4–1.5 m/s. The long and thin finned AT shows better enhancement of heat transfer, but the heat transfer performance factor also accounting for frictional losses is higher for short and thick fin. Simultaneously, increasing the number of long and thin fins in the AT would not improve much the heat transfer performance.

Keywords

Fin, Flat-plate radiation shield, Heat transfer, Large-aperture parabolic trough concentrator, Semi-circular absorber tube

DOI

10.1016/j.renene.2020.12.054

Citation

Gong , J H , Wang , J , Lund , P D , Zhao , D D , Xu , J W & Jin , Y H 2021 , ' Comparative study of heat transfer enhancement using different fins in semi-circular absorber tube for large-aperture trough solar concentrator ' , Renewable Energy , vol. 169 , pp. 1229-1241 . https://doi.org/10.1016/j.renene.2020.12.054

Permanent link to this item

https://urn.fi/URN:NBN:fi:aalto-202103032200

Collections

[article-cris] Perustieteiden korkeakoulu / SCI

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