Efficiency enhancement of the parabolic trough solar collector using the rotating absorber tube and nanoparticles

Research output: Contribution to journalArticlepeer-review

Abstract

Enhancing the thermal performance of parabolic trough collectors (PTC) is of major interest to maximize solar energy absorption. In common PTCs, solar irradiation is focused on the lower part of the absorber tube which causes high temperatures, thermal stress, and tube deformation. To overcome these problems, it is suggested to rotate the absorber tube with a specified frequency to reduce the high surface temperature and increase the solar energy absorption. In addition, a nanofluid (Al2O3-Therminol) is utilized as the heat-carrying fluid. Effects of various parameters, including the rotational speed, absorber tube material, flow rate, and nanoparticles concentration on the collector efficiency were studied. An approximate 2D-transient model of PTC is proposed and a steady-laminar numerical simulation is conducted for the 3D cases. Results indicate that the aluminum is the best choice among the other materials used for the absorber tube, providing about 16 K higher output temperature which is nearly 5% higher than that of the steel. Also, a more uniform surface temperature distribution and a higher collector thermal efficiency could be met. Accordingly, an average increase of 15% in the thermal efficiency of the collector and a maximum decrease of 64 K in the absorber tube temperature are reachable.

Bibliographical metadata

Original languageEnglish
Pages (from-to)569-584
Number of pages16
JournalRenewable Energy
Volume145
DOIs
Publication statusPublished - 1 Jan 2020