Modeling Different Nanofluid Particles and Underground EAHE System to Decrease the Power Transformer Temperature

In this study, a theoretical model of the power transformer 250 kV has been designed by ANSYS17.1/FLUENT code program which has been connected to an underground tube (earth air heat exchanger EAHE) where air has passed through it. The hot ambient air of velocity 6 m/s has been cooled inside the EAHE and the air has been released at a low temperature to cool the transformer walls and then it cooled the internal parts of the transformer. The study included also the addition of nanoparticles to the cooling oil to increase the process of removing the heat generated inside the transformer. The study showed, by using the nanoparticles of (SiC) with volume fraction of 9% in the cooling oil using the EAH system, that the oil temperature has been reduced to about 32 °C as average temperature using SiC and TiO2 nanofluid particles in comparison with the temperature of 29 °C when adding Al2O3 and also 27 °C temperature adding Cu nanoparticles with 9% volume fraction.