Enhancing Thermo-Economic Performance of TiO 2 -Water Nanofluids: An Experimental Investigation

  • PDF / 992,746 Bytes
  • 10 Pages / 593.972 x 792 pts Page_size
  • 79 Downloads / 173 Views

DOWNLOAD

REPORT


https://doi.org/10.1007/s11837-020-04336-9 Ó 2020 The Minerals, Metals & Materials Society

NANOMECHANICS OF LOW-DIMENSIONAL MATERIALS

Enhancing Thermo-Economic Performance of TiO2-Water Nanofluids: An Experimental Investigation SAYANTAN MUKHERJEE,1 PURNA CHANDRA MISHRA and PARITOSH CHAUDHURI2,3

,1,4

1.—Thermal Research Laboratory (TRL), Kalinga Institute of Industrial Technology (Deemed to be University), Campus-8, Patia, Bhubaneswar, Odisha 751024, India. 2.—Institute for Plasma Research (IPR), Bhat, Gandhinagar, Gujarat 382428, India. 3.—Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India. 4.—e-mail: [email protected]

In this study, the thermal and cost performance of TiO2-water nanofluids was investigated. Stable nanofluids were formulated by dispersing TiO2 nanoparticles in water as the base fluid. Thermal conductivity and viscosity of nanofluids were measured at 0.1–1 wt.% over the temperature range 25–65°C. The effects of constituent material properties were also analyzed. Enhancements in thermal conductivity and viscosity of the nanofluid were obtained. Thermal conductivity increased with concentration and temperature rise, whereas the viscosity increased with wt. fraction and decreased with temperature elevation. Thermal conductivity and viscosity were also influenced by material properties. The resultant data were compared with the published models and a wide deviation was observed. New models for thermal conductivity and viscosity of nanofluids with very high accuracy are proposed. Thermal performance based on the measured thermo-physical properties was analyzed. It was observed that nanofluids are suitable for heat transfer. Finally, a cost performance analysis was carried out to inspect the economic feasibility of nanofluids. List C f k KB M n NA Pi P PPI t Up Uv V u

of Symbols Cost or price ($/g) Frequency (Hz) Thermal conductivity (W/m–K) Boltzmann constant (1.3807 9 1023 J/K) Molar mass (kg/mol) Number of experimental runs Avogadro number (6.023 9 1023) Individual measurement of a parameter Average of all measurements of a parameter Price-performance index Time (s) Overall uncertainty Uncertainty in measurement of individual parameter Molar volume (m3/mol) Velocity (m/s)

Greek Letters q Density (kg/m3) U wt. fraction (%) k Wavelength (m) l Viscosity (cP) (Received April 18, 2020; accepted August 17, 2020)

x

Weight (g)

Subscripts bf Base fluids np Nanoparticles nf Nanofluids

INTRODUCTION Ultrafast cooling performance is very important for several situations such as automobiles, nuclear reactors, power plants, chemical and process industries, etc. The operation and safety of such industries depend on the thermal performance of the heat transfer equipment.1 Nanofluids, which are engineered colloids of ultrafine nanoparticles (typically < 100 nm) dispersed in base fluids, are very promising as working fluids for better heat transfer performance in such equipment. Enhanced thermophysical properties, better stability, and less corrosion and damage to the system compared w