Fundamental Study and Modeling of Nanofluids

Abstract

In spite of all the recent studies, the insulating materials employed for high voltage (HV) transformer manufacturing are still those in use since several decades. For the fluid insulation, mineral oil (MO) still dominates thanks to its excellent dielectric and cooling performances. Anyway, since it is a carcinogenic agent, the electric industry searched alternatives for applications where environmental concerns are of greater concern (e.g., offshore equipment, trains). In this context, many efforts have been done to study green uids, mostly natural and synthetic esters, to replace MO. However, green alternatives have a low resistance to electrical discharge propagation. Some researchers have started to experiment with MO-based nano uids (i.e., colloidal solutions of nanoparticles in a base fluid), with the aim of improving the MO heat exchange capabilities. They have started to study nano fluids because of their outstanding thermal properties, but these fluids should be excellent also regarding all the electrical properties, ranging from the power losses to the discharge propagation resistance. Target of this thesis is to perform a fundamental study aimed at understanding if nanofluids are a real possible alternative for mineral oil.