ENHANCING THE THERMAL PERFORMANCE OF PARABOLIC TROUGH SOLAR COLLECTORS USING NANOFLUIDS AND INTERNAL LONGITUDINAL FINS

Abstract

In this study, the thermal performance of parabolic trough absorber tube with internal longitudinal fins in combination with the use of oil-based nanofluids with different volume fractions of Al2O3 is being analyzed numerically by solving the governing equations using ANSYS FLUENT 17.1 software. An optical modeling tool that uses Monte-Carlo ray-tracing techniques (Soltrace®) was used to obtain the non-uniform heat flux distribution on the parabolic trough absorber tube. The results show that the use of internal longitudinal fins leads to the highest thermal efficiency and the highest pressure drop as well, the thermal enhancement with nanofluid reaches up to 1.16%, while the enhancement using internal fins was up to 6.8% and with their combination, the enhancement reached 7.25%. This enhancement was a result of the reduction of the circumferential temperature of the absorber tube.