Cooling properties of natural ester modified by nanopowders fullerene C60 and TiO2 for high voltage insulation applications

The paper presents analysis of thermal properties of natural ester modified by nanoparticles C
₆₀
and TiO
₂
, used in power transformers. The measurements of thermal properties, such as thermal conductivity, kinematic viscosity, specific heat, density, and thermal expansion were carried out. Measurements were carried out at a temperature of 25 °C, 40 °C, 60 °C and 80 °C. On the basis of measurement results, the heat transfer coefficient α of natural ester admixed with nanoparticles was calculated. Coefficient α of pure natural ester and the coefficient of natural ester modified by nanoparticle C
₆₀
and TiO
₂
were compared.