Flow Investigation of natural convection in power transformer with nano-oil using lattice Boltzmann method

Abstract

Improving the transformer oil's thermal performance is necessary since transformers are essential in power distribution networks and besides, the transformer core's temperature has an impact on how well it functions electrically. In this study, by presenting a two-dimensional model of a transformer, the natural convection heat transfer of one nano-oil sample, including Al2O3 nanoparticle in base fluid of Naphthenic oil has been investigated theoretically and simulated by the lattice Boltzmann method and D2Q9 model. Modelling and solving were done for nanoparticle volume fractions of 0% to 5% and Rayleigh numbers of 103 to 105. Flow lines and Nusselt number average are given in this range. Based on the results of this research, adding nanoparticle to the base fluid has improved the cooling operation of the transformer core. Also, increasing the volume fraction of nanoparticles and the Rayleigh number increased the natural convection heat transfer. Naphthenic-Al2O3 nano-oil, at a volume fraction of 5% and Rayleigh number of 105, has the highest Nusselt number average of 13.06 and the heat transfer compared to pure Naphthenic oil under the same conditions has improved.