Improvements in heat transfer network modelling for oil-cooled power transformer windings

Abstract

Papers presented to the 11th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 20-23 July 2015.In this paper accurate modelling of heat transfer from power transformer winding conductors to cooling oil is envisaged. To this end the network model of Radakovic & Sorgic [1] is validated against more detailed CFD simulation results. Based on this comparison, three model improvements to the network model are proposed. They concern the governing heat transfer correlation, the introduction of thermal boundary layer tracking and an improved description for the thermal resistance in the solid. The improved network model results in more accurate results.