Numerical analysis of the cold start of a distribution transformer filled with biodegradable oil

GARELLI LUCIANO; RIOS RODRIGUEZ GUSTAVO; MARIO A. STORTI; AMADEI MAURO; ALFREDO ORTIZ

Foz do Iguaçu

Congreso; XLIII Ibero-Latin American Congress on Computational Methods in Engineering; 2022

Associação Brasileira de Métodos Computacionais em Engenharia (ABMEC)

This work presents a numerical analysis of the cold start of a distribution transformer filled with biodegradable oil in order to obtain a detailed description of temperatures and velocities distributions inside the transformer. When the transformer is placed in very extreme conditions, like in a wind farm with very low ambient temperature, and is filled with biodegradable oil the pour point of the oil can be reached. This type of analysis has not been necessary since mineral oils have very low pour point temperatures, below −40 °C, but in the case of conventional sunflower oil can be −18 °C. When the transformer is started from a temperature near the pourpoint the fluidity and hence the natural convection phenomena, which is the principal mechanism of the heat transportation inside the transformer, can be dramatically reduced. This reduction can lead to a local increase in the oiltemperature, principally in the windings oil channels. In this work, several working temperatures are analyzed for a transformer with a rated power of 315 kVA and a voltage ratio of 13.2kV/0.4kV filled with biodegradable oil,through three-dimensional thermo-fluid dynamics simulations using the multiphysics scientific code Code Saturne.This work is carried out as part of the EU Horizon 2020 BIOTRAFO project.