The present review paper aims to document the latest developments on the applications
of nanofluids as working fluid in parabolic trough collectors (PTCs). The influence of many factors
such as nanoparticles and base fluid type as well as volume fraction and size of nanoparticles on the
performance of PTCs has been investigated. The reviewed studies were mainly categorized into
three different types of experimental, modeling (semi-analytical), and computational fluid
dynamics (CFD). The main focus was to evaluate the effect of nanofluids on thermal efficiency,
entropy generation, heat transfer coefficient enhancement, as well as pressure drop in PTCs. It was
revealed that nanofluids not only enhance (in most of the cases) the thermal efficiency, convection
heat transfer coefficient, and exergy efficiency of the system but also can decrease the entropy
generation of the system. The only drawback in application of nanofluids in PTCs was found to be
pressure drop increase that can be controlled by optimization in nanoparticles volume fraction and
mass flow rate.
