Abstract:
Transformer plays a significant role in providing a reliable and useful electricity
supply. It is one of the most critical equipment in electric power transmission and
distribution systems. Transformer losses are occurred by the current passing through
resistance on the winding conductors. These losses are converted to heat energy. The
majority of high voltage transformers are filled with liquids that work as an
electrical insulation as well as a heat transfer medium. The most commonly used
liquid in power transformers is mineral oil due to its low cost and good properties.
The winding temperature must be kept within a limit so that the temperature
dependent properties of the mineral oil do not hamper the performance of the
transformer. Therefore, an air cooled radiator is generally fixed with the transformer
to maintain the temperature of the mineral oil to its tolerable limit. In this study, heat
transfer enhancement is investigated for different types of radiator filled with
mineral oil. The thermal performance of conventional radiator and modified radiator
with and without fin arrangement are analyzed through simulation and experimental
results. A 200 kVA, 11 kV Oil Natural Air Natural (ONAN) cooled 3-φ distribution
transformer is used for experiment. The simulation is performed using Solid Works
3D CAD Design and ANSYS 2016 version Software. A critical analysis is done
with the experimental results for the transformer radiator with and without fin
arrangement. The thermal performance of the radiator of 14 oval pipes with fin
arrangement increases 3.45% as compared to the radiator of 14 oval pipes without
fin arrangement. The cost of the radiator of 14 oval pipes with fin arrangement
reduces 20.89% as compared to the conventional radiator without fin arrangement.
The results obtained through simulation and experiment play vital role in the
economical design of transformer radiator so that fabrication of transformer is cost
effective.
