Nanofluid Based on New Generation Transformer Oil: Synthesis and Flow Properties
Katarína Paulovičová, Jana Tóthová, Michal Rajňák, M. Timko, P. Kopčanský, V. Lisý
Abstract
In this paper, we focused on synthesis, basic characterization and flow properties of nanofluids in which a new generation transformer oil as carried liquid was used. These oils are known as GTL based transformer oils due to Gas-To-Liquids technology developed for producing iso-paraffinic hydrocarbon that were derived initially from natural gas. GTL oils are purer, chemically stable and have significantly higher lightning impulse breakdown voltage than normally used mineral oils on the paraffinic and the naphthenic base. Prepared nanofluids (NFs) contain ferrimagnetic nanoparticles of magnetite (MNPs) with a spinell structure. By employing chemical co-precipitation technique MNPs were synthesized. The mass concentration of the suspended MNPs in NFs was changed from 0.2 to 13.3%, and the M-H loops revealed the superparamagnetic behavior of NFs recorded at room temperature. The mass fraction and average particle size of MNPs were obtained from vibrating-sample magnetometer measurements. In turn, rheological characterization of NFs was performed by using a rotational rheometer in the temperature range from 293 to 353 K in dependence of the shear rate. The experimental results show that the crucial properties of GLT oil are positively reflected in the properties of the prepared NFs.