Design and optimization of fin-assisted cooling for power transformers

The present case illustrates an analytical procedure to determine the optimal distance among fins to install on the surface of a power transformer in order to guarantee an adequate cooling. Thermal balances to describe the problem are developed in detail (i.e., fins equations, thermal properties as function of the temperature, etc.), and the calculation model can be developed within a spreadsheet. Only basic Nusselt number correlations are considered in the model to keep the solution simple and intuitive. The optimal design is the one which guarantees the highest heat transfer rate from the transformer surfaces to achieve the maximum cooling capacity. The developed model allows to perform sensitivity analyses easily by changing the material or geometrical features of the fins.