Experimental Determination of Nanoparticle and Surfactant Concentration in Silica Nanofluid for Transformer Insulation

Nanofluids in high-voltage engineering are used for heat transfer and dielectric insulation purposes. With a small amount of nanosized particles added to them, they exhibit properties similar to the bulk material. Nanofluids made from transformer oil are reported to perform better at heat transfer and have higher thermal conductivity than regular transformer oils. They also have better insulation properties. This work studies the electrical and physical properties of the silica nanoparticles-based transformer nanofluid. Further, it investigates the influence of the surfactant Cetyl Trimethyl Ammonium Bromide (CTAB), on the properties of silica nanofluid. It also quantifies the amount of Silica and CTAB to be added to the nanofluid. The optimum values of Silica (SiO
2
) and CTAB nanoparticles dispersed in mineral oil to achieve enhanced dielectric Breakdown voltage (BDV) with improved physical properties are obtained by experimentation. As per the experimental results, the optimized level of silica concentration in silica nanofluid (SNF) is 0.05g/L. Adding silica nanoparticles and CTAB enhances the AC BDV and Inter Facial Tension (IFT) of SNF. In comparison with virgin mineral oil, SNF with CTAB shows 79.16% and 90.84% percentage enhancement in AC BDV and IFT, respectively. SNF with CTAB shows improved flash point and fire point values as well.