Effect of fin geometry on natural convection heat transfer in electrical distribution transformer: Numerical study and experimental validation

Abstract

A numerical model and experimental validation were studied on a 250 kVA, 11 kV oil-immersed electrical distribution transformer. Experimental data were locally obtained for temperature monitoring as a function of time. The numerical model was constructed using the ANSYS fluent 15 software. The observations between the experimental and theoretical temperature values were properly validated. The model was used to study the fin geometry effect on temperature and natural flow currents inside the transformer. Four fin designs were suggested and compared with a standard design, which was rectangular. The rectangular design with ventilation channels (Design A) had a similar effect as the standard design. The perforated rectangular design (Design B) was slightly better in performance. The wide upper side parallelogram design (Design C) had the best thermal performance, whilst the standard design was better than the wide lower side parallelogram (Design D) in terms of thermal distribution.