An experimental investigation on the simultaneous effects of helically corrugated receiver and nanofluids in a parabolic trough collector

Improving performance of parabolic through collectors is one of the challenges in thermal application of solar energy. Nanofluids are one of the most effective methods that are used for heat transfer enhancement in the absorber of parabolic through collectors. Also, corrugated tubes can increase turbulence intensity and therefore heat transfer can experience a remarkable improvement. In this study, the effects of Al2O3/water nano fluid at volume fractions of 0.25-1% and helically corrugated absorber tubes with the pitch length of 3-7 mm and roughness height of 0.5-1.5 mm are investigated on the thermal behavior of a parabolic trough collector (PTC). All tests have been conducted under ASHRAE standard (93:2010). The results demonstrated an increase of about 219.56% in Nusselt number. In comparison, they showed an increase around 145.5% in friction factor. Also, at 1% vol. Al2O3/water nanofluids, the thermal performance factor reached the maximum value of 2.53% at the pitch length of 3 mm and roughness height of 1.5 mm. (c) 2021 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Automated summary

This study investigates the improvement of thermal performance in a parabolic trough collector using nanofluids and corrugated absorber tubes. Results show a significant increase in Nusselt number and friction factor, with the thermal performance factor reaching its maximum at specific conditions.