A brief review of the application of ferrofluids and magnetic fields in solar energy systems

Abstract

Solar energy devices must constantly work at a suitable thermal efficiency in order to be economical. On the other hand, it has been found that ferrofluids and magnetic fields can improve heat transfer rates in energy conversion systems. Therefore, they have the potential to enhance the performance of solar-based devices. This investigation examines recent studies on the application of ferrofluids and magnetic fields in solar devices. Ferrofluids and magnetic fields are introduced and their most widely used areas are described. The studies conducted on the applications of magnetic fields and ferrofluids in PV and PV/T systems are reviewed, and the most important factors affecting the efficiency of these systems are classified. It is clear that magnetic nanofluids in the presence of a magnetic field will always perform better compared to the state without a magnetic field and pure water. The most critical parameters for improving the performance of these systems are the magnetic field intensity, ferrofluid flow rate, the direction of the magnetic field and its rotation, and the volume fraction of nanoparticles in ferrofluid. Among solar devices integrated with magnetic fields, flat-plate solar collectors have the best compatibility in improving system performance even at higher induction intensities such as 1 T (10,000 G). This can increase the outlet temperature up to 100 °C in low volume fractions and improve the thermal efficiency of the system by up to 40 %.