ETHYLENE GLYCOL-BASED NANOFLUIDS – ESTIMATION OF STABILITY AND THERMOPHYSICAL PROPERTIES

摘要

This article is a summary of research involving the evaluation of the thermo-physical properties of Mono-ethylene - glycol-based solar thermic fluids oxidized multiwalled carbon nanotubes. Nanofluids were prepared with Mono-ethylene glycol and water as base fluids in 100:0, 90:10 and 80:20 ratios. These base fluids of three categories were dispersed with purified and oxidized multiwalled carbon nanotubes (MWCNTs) in the weight fractions of 0.125, 0.25 and 0.5 percentages. The variation in zeta potential is studied to examine the dispersion stability during 2 months. Thermal conductivity and dynamic viscosity were measured by hot disk method and Anton paar viscometer respectively. Significant enhancement of thermal conductivity by 15 to 24 % was observed when the base fluids are dispersed with MWCNTs. Viscosity was observed to be increasing in the temperature range of 50 to 70 oC but found to be less significant in higher temperature ranges. The variation of dynamic viscosity and thermal conductivity is minimum for a period of two months due to good stability of nanofluids. A comprehensive mathematical equation suitable for all weight fraction of MWCNTs and volume percentages of Mono-ethylene glycol was developed. The correlation could fit well with the experimental data in reasonable limits.