Simulation of nanofluid as a two-phase flow in a distribution transformer

In this article, the natural convection heat transfer of Fe304/oil and graphene/oil nanofluids and mineral oil inside a 200 kVA distribution transformer is numerically studied. The Fe304/oil and graphene/oil nanofluids were simulated as a mixture two-phase flow where mineral oil was modeled as a single-phase flow with the temperature dependent thermophysical properties. Based on the simulation results, the nanoparticles when dispersed in oil enhance the convective heat transfer of oil and decrease its hotspot temperature. So that, the hotspot temperature of the Fe304/oil and graphene/oil were respectively 1 °C and 4.5 °C lower than that of the mineral oil. In addition, the transformer filled with graphene/oil nanofluid experienced considerably lower temperature in the thermally critical region. According to the obtained results, employing the nanofluid improves the cooling performance of the transformer, which leads to a more reliable operation and longer life.