Análise térmica de radiadores de transformadores elétricos utilizando o método de elementos finitos

Abstract

As any other electric equipment, transformers have efficiency lower than 100%. The “lost” energy is dissipated as heat in the active part of the machine and later this heat must be transferred to the outside environment, in order to refrigerate the machine. Transformer operation with higher temperature than it was designed to operate will reduce the lifetime of the machine. In this sense, this work brings a parametric analysis of radiators with thermal simulations using the finite elements method, aiming to identify changes in the geometry of the transformer that improve the cooling system of the equipment. This work also presents a revision about electric transformers and a specific study about its thermal behavior. Simulations were developed in the ANSYS CFX® software and they were based on a simplified model of transformer, that consider the active part of the machine as a block dissipating as heat the lost energy in Joules. The results were made by comparing the values of average temperature and top oil temperature obtained in each simulation. To ensure the comparisons’ validity, all cases have the same simulation parameters and the finite elements meshes were generated in a similar form.