Numerical Study of Cooling Solutions Inside a Power Transformer

In this paper we study the fluid flow and heat transfer by convection in a thermo-convective circuit with several cooling channels and different inlet fluid velocities. A numerical study has been conducted in steady state for a step-down 3-phase power transformer in columns immersed in a mineral oil bath inside of a tank. Our main objective is the cooling optimization of the power transformer. An obstacle is used at the inferior part of the transformer in order to conduct the oil to the hottest surface. In order to study the influence of the different parameters on both the heat transfer and the fluid flow we have made use of the highest and the bulk temperature as well as the volume flow rate and dimensionless numbers Re and RiRe in every channel. The obtained results show an optimal velocity where the temperatures are kept below the limits.