Synthesis of ZrO2 Based Nanofluids for Cooling and Insulation of Transformers

Nanofluids have recently emerged as an important new technology for heat transfer in various engineering applications. In this work, zirconia nanoparticles (ZrO2) were synthesized using a microwave-assisted sol-gel method for the preparation of nanofluids through a two-step synthesis process. The electrical, thermal and rheological properties of the nanofluids produced were studied as a function of the ZrO2 concentration (g/L). These fluids showed potential as an alternative to the traditionally available ester-based transformer oil. The effect of the ZrO2 nanoparticle additions on the nanofluid was evaluated by measurements of thermal conductivity, breakdown voltage, and viscosity. The results show an improvement in cooling, insulation, and breakdown voltage due to ZrO2, which is explained in terms of a nanoparticle-assisted charge capture mechanism. The optimal performance of the nanofluid was obtained for a concentration of 0.2 g/L of ZrO2 nanoparticles in the transformer oil.