Improving Heat Transfer in Parabolic Trough Solar Collectors by Magnetic Nanofluids

A parabolic trough solar collector (PTSC) converts solar radiation into thermal energy. However, low thermal efficiency of PTSC poses a hindrance to the deployment of solar thermal power plants. Thermal performance of PTSC is enhanced in this study by incorporating magnetic nanoparticles into the working fluid. The circular receiver pipe, with dimensions of 66 mm diameter, 2 mm thickness, and 24 m length, is exposed to uniform temperature and velocity conditions. The working fluid, Therminol-66, is supplemented with Fe3O4 magnetic nanoparticles at concentrations ranging from 1% to 4%. The findings demonstrate that the inclusion of nanoparticles increases the convective heat transfer coefficient (HTC) of the PTSC, with higher nanoparticle volume fractions leading to greater heat transfer but increased pressure drop. The thermal enhancement factor (TEF) of the PTSC is positively affected by the volume fraction of nanoparticles, both with and without a magnetic field. Notably, the scenario with a 4% nanoparticle volume fraction and a magnetic field strength of 250 G exhibits the highest TEF, indicating superior thermal performance. These findings offer potential avenues for improving the efficiency of PTSCs in solar thermal plants by introducing magnetic nanoparticles into the working fluid. © 2024, Tech Science Press. All rights reserved.