Lattice Boltzmann simulation of thermal investigation of natural convection in power transformer with nano-oil

Abstract

The improvement of the thermal performance of transformer oil is essential due to the crucial role transformers perform in power distribution networks. Additionally, the electrical performance of a transformer is influenced by the temperature of its core. The natural convection heat transfer of a nano-oil sample, containing an Al2O3 nanoparticle in the base fluid of Paraffinic oil, has been studied theoretically and simulated by the lattice Boltzmann method and D2Q9 model in this paper, which presents a two-dimensional model of a transformer. For nanoparticle volume fractions of 0% to 5% and Rayleigh numbers of 103 to 105, modelling and solutions were carried out and, in this range, temperature charts and average Nusselt number are provided. In light of the findings of this study, adding nanoparticle to the base fluid has improved the cooling operation of the transformer core. Additionally, the natural convection heat transfer was enhanced by increasing the Rayleigh number and the volume fraction of nanoparticles. Paraffinic-Al2O3 nano-oil, at a volume fraction of 5% and Rayleigh number of 105, has the highest Nusselt number average of 13.07 and under the same conditions, the heat transfer has improved as compared to pure Paraffinic oil.