Thermal properties of mineral oil admixed with C60 and TiO2 nanoparticles

Work on modification of insulating liquids with different nanoparticles to improve their electric properties has been done for many years. However, possible changes of thermal properties of such liquids have not been in focus. The article presents an analysis of nanoparticle influence on thermal properties of mineral oil used in transformers. The investigated nanoparticles were fullerenes C
₆₀
and barium oxide TiO
₂
. The measured thermal properties were thermal conductivity, specific heat, viscosity, density, and the thermal expansion. On the basis of measurement results of the mentioned thermal properties, the authors calculated the heat transfer factor α. This factor determines the ability of a liquid to carry away heat and it has the key influence in transformer cooling. The measurements were done for a wide temperature range from 25 to 80°C.