@conference{10902/13369,
year = {2017},
url = {http://hdl.handle.net/10902/13369},
abstract = {This work compares the temperature distribution and hot-spot temperatures obtained in a disc-type winding of a power transformer when using as dielectric liquid a mineral oil or natural esters. The comparison is made with a reference case for mass flow rate and temperature in the inlet and uniform losses for the discs. A further comparison is performed by increasing the mass flow rate at the inlet form 0.78 kg/s to 0.9 and 1.0 kg/s, thus nine case studies are considered in this work. These cases have been analyzed via CFD techniques using the software COMSOL Multiphysics® with a 2D-axysymmetrical model using the Conjugate Heat Transfer module. For the analysis, the hotspot factor H is considered as an indicator of the cooling circuit efficiency since the losses are uniform. Results shows that for the base case, the hot-spot temperature obtained for the mineral oil is 9-11°C higher than the obtained with esters whereas for the increased mass flow rate, hot-spot temperature of mineral oil is equal or even lower than the obtained for natural esters. The analysis of the hot-spot factor shows the dependence of the cooling circuit efficiency on the kind of oil and inlet conditions.},
organization = {The research leading to these results has received funding from multiple sources over years, but we would specifically like to acknowledge the support received in the later stages from the Spanish Plan Estatal de I+D under the grant agreement DPI2015-71219-C2-1-R. Also A.Santisteban would like to thank the University of Cantabria and the Government of Cantabria for the supporting of his Ph.D. scholarship.},
publisher = {Institute of Electrical and Electronics Engineers, Inc},
publisher = {19th IEEE International Conference on Dielectric Liquids (ICDL), Manchester, 2017, 444-447},
title = {Thermal analysis of natural esters in a low-voltage disc-type winding of a power transformer},
author = {Santisteban Díaz, Agustín and Ortiz Fernández, Félix and Fernández Diego, Inmaculada and Delgado San Román, Fernando and Ortiz Fernández, Alfredo and Renedo Estébanez, Carlos J.},
}