Eventos Anais de eventos
ENCIT 2022
19th Brazilian Congress of Thermal Sciences and Engineering
Experimental Evaluation on the effect of magnetite in aerogel form on the dielectric breakdown strength and thermal conductivity of a synthetic isolating oil
Submission Author:
Lucas Militão , SC
Co-Authors:
Lucas Militão, Alexandre Kupka da Silva, Jader Riso Barbosa Jr., Douglas Machado, Joseane Caroline Bernardes, Bruno Neckel Wesling, Carlos Rambo
Presenter: Lucas Militão
doi://10.26678/ABCM.ENCIT2022.CIT22-0724
Abstract
Nowadays, the recent trend of miniaturizing power electronics systems led to higher power dissipation per unit area, demanding an enhancement of thermal properties of isolating oils. This study proposes to improve the thermal conductivity (while having admissible dielectric breakdown strength) of widely used commercial synthetic oil, by adding magnetite in aerogel form. Mass fractions of nanoparticles and aerogel of 0.01\% and 0.05\% were investigated experimentally, and the results were compared with those of the base fluid. A FOX 50 Thermal Conductitivty Meter was used to assess thermal conductivity and a HMRDT-100 dielectric breakdown testing equipment measured the breakdown voltage through the short-time method with controlled fluid temperature. The results indicated an increase of thermal conductivity and electric breakdown strength in the majority of the test samples when compared to the isolating oil. An increase of 22\% of the electric breakdown strength and 1.5\% of the thermal conductivity was observed for the 0.05 wt\% $Fe_{3}O_{4}$ aerogel sample. Therefore, the addition of $Fe_{3}O_{4}$ aerogel to commercial synthetic isolating oil is a promising alternative to nanoparticles to enhance thermal conductivity and electric breakdown strength, due to their smaller particle size and consequently larger surface area which lead to better dispersion stability.Yet, higher mass fractions of magnetite aerogel in isolating oil must be investigated and other thermal properties should be assessed in order to establish it as a novel coolant for electronics.
Keywords
magnetite, aerogel, isolating oil, electric breakdown strength, thermal conductivity
