A comprehensive investigation on the efficiency of alumina nanoparticles in ONAN and OFAN cooling performance enhancement of transformers

This study is devoted to thermal and electromagnetic investigations of transformers with the approach of employing Alumina nanoparticles in the coolant fluid. Standing among metal-oxide nanomaterials with the finest thermal properties, Alumina can effectively be employed as an additive in transformer oil to produce nanofluid, demonstrating noticeable merits associated with the coolant system derived temperatures over the pure fluid. Moreover, the application of Finemet core in transformer construction is assessed versus commonly used cores so as to verify its capability in providing reduced core losses. However, to remedy the previous researches drawbacks, this study attempts to evaluate the nanocrystalline core drastic impact on enhancing the resultant temperatures in the studied three-phase transformer. Apart from that, application of transformer oil based Alumina nanofluid under both natural and forced convection flows of the coolant, considered as the first-ever effort toward achieving satisfactory levels of the system cooling performance in presence of the designated nanopowder, is comprehensively assessed in four different cases. Again, the novelty and practicability of the scheme can be highlighted readily once lesser rates of hotspot temperature are gained through complete analysis of active and nonactive components under different loading power factors. The correctness of temperature field patterns is validated benefiting qualitative comparison between the simulation results and the experimental tests comprising thermal images from infrared camera. Furthermore, the Alumina nanofluid Nusselt numbers versus the Rayleigh and the Reynolds numbers, in accordance with natural and forced convections, respectively, are acquired to represent the simulation results good agreement with the experimental values. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

This study focuses on the thermal and electromagnetic investigations of transformers using Alumina nanoparticles in the coolant fluid, as well as comparing the performance of Finemet core with commonly used cores. The results show significant improvements in cooling performance and reduced core losses with the application of Alumina nanofluid and nanocrystalline cores in transformer construction. Additionally, the study validates simulation results through qualitative comparisons with experimental tests, showing good agreement between Nusselt numbers and Rayleigh/Reynolds numbers under different convection flows.