Synthesis of ZrO<sub>2</sub> Based Nanofluids for Cooling and Insulation of Transformers
Harsh Vaishnav, Kumar Navin, Rajnish Kurchania, Richard Ball
Abstract
Nanofluids have recently emerged as an important new technology for heat transfer in various engineering applications. In this work, zirconia (ZrO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) nanoparticles 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 ZrO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> concentration (g/L). These fluids showed potential as an alternative to the traditionally available ester-based transformer oil. The effect of the ZrO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanoparticle additions on the nanofluid was evaluated by the measurements of thermal conductivity, breakdown voltage (BDV), and viscosity. The results show an improvement in cooling, insulation, and BDV due to ZrO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , 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 ZrO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanoparticles in the transformer oil.