Numerical modelling of natural convection of oil inside distribution transformers

Abstract

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Numerical modelling of natural convection of oil inside distribution transformers

Numerical analysis of the hot-spot temperature of a power transformer with alternative dielectric liquids

“…Torriano et al [4] performed simulations of a low-voltage winding (LVW) of a power transformer with zigzag cooling in order to determine the accuracy of different 2D axisymmetric models based on coupling CFD and heat transfer. In 2011, Gastelurrutia et al [5] carried out a study where the developed a 3D and a 2D model of an ONAN (Oil Natural-Air Natural) distribution transformer by using CFD techniques. The simplified 2D model has a good capacity to represent the thermal behavior of the whole transformer.…”

Improvement of thermal performance of generator step-up transformers

“…Convection cooling by air and oil was accounted by empirical relations for heat transfer coefficients rather than running a fluid dynamics analysis. As it is known to the authors, fluid dynamics approach has been employed in 3D modeling of oil-immersed distribution transformers [8] or even dry type transformers [9]. In case of large power transformers, numerical calculation of fluid dynamics has found its use in 2D [10] and 3D [11] calculations of winding temperatures.…”

Thermal Design of Power Transformers via CFD

“…This is aimed at separating the inner part that consists mainly of Cu, from the outer region, where the dominant part of the Nomex 410 insulation is located. Their mixture material properties are calculated via: (6) Here n mat is no. if considered structural materials, V volume, c p specific heat at constant pressure,  volume fraction, and x mass fraction.…”

“…Furthermore, combined oil and air flows in distribution transformers were investigated with commercial CFD codes by Fonte et al [5] and Gastelluritia et al [6].…”