Thermal Conductivity and Stability of Novel Aqueous Graphene Oxide–Al2O3 Hybrid Nanofluids for Cold Energy Storage

Abstract

Thermal ice storage has gained a lot of interest due to its ability as cold energy storage. However, low thermal conductivity and high supercooling degree have become major issues during thermal cycling. For reducing the cost and making full use of the advantages of the graphene oxide–Al2O3, this study proposes heat transfer enhancement of thermal ice storage using novel hybrid nanofluids of aqueous graphene oxide–Al2O3. Thermal conductivity of aqueous graphene oxide–Al2O3 nanofluid was measured experimentally over a range of temperatures (0-70 °C) and concentrations. Thermal conductivity of ice mixing with the hybrid nanoparticles was tested. The influences of pH, dispersant, ultrasonic power and ultrasonic time on the stability of the hybrid nanofluids were examined. A new model for the effective thermal conductivity of the hybrid nanofluids considering the structure and Brownian motion was proposed. The results showed that pH, dispersant, ultrasonic power level and ultrasonication duration are important factors affecting the stability of the hybrid nanofluids tested. The optimum conditions for stability are pH = 11, 1% SDS, 375 W ultrasonic power level and 120 min ultrasonic application time. The thermal conductivity of hybrid nanofluids increases with the increase of temperature and mass fraction of nanoparticles. A newly proposed thermal conductivity model considering the nanofluid structure and Brownian motion can predict the thermal conductivity of hybrid nanofluids reasonably well.

Dual Solutions of Unsteady Mixed Convection Hybrid Nanofluid Flow Past a Vertical Riga Plate with Radiation Effect

“…Therefore, the hybrid nanofluid can be employed in a wide range of areas, such as electronic cooling, heat exchangers, military equipment, automotive, solar collectors, and refrigeration systems, in place of mono-nanofluids and conventional fluids [1,2]. In addition, hybrid nanofluids can also be used to enhance the heat transfer performance of cold storage and solar thermal energy storage systems (see Shao et al [3]; Dubal et al [4]; Vaka et al [5]; Selimefendigila et al [6]; Gao et al [7]; Maleki et al [8]; and Alrowaili et al [9]). Turcu et al [10], Jana et al [11], and Suresh et al [12] were among the first researchers to do experimental research on the development of hybrid nanofluids.…”

Thermal conductivity and viscosity of Al 2 O 3 ‐ZnO‐MWCNT‐EG ternary nanofluid

“…The enhanced thermophysical property of nanofluid caught the attention of many researchers making them study the behavior of different nanoparticles in different based fluids. Yugo Goa et al 5 studied the thermal conductivity of graphene oxide-Al 2 O 3 hybrid nanofluid for a temperature ranging from 0 to 70 C. They reported an increase in thermal conductivity with an increase in temperature and mass fraction of nanoparticles. Suresh et al 6 reported a 12.11% improvement in thermal conductivity for Al 2 O 3 -Cu-Water nanofluid (90:10) for a volume concentration of 2%.…”

Effect of Magnetic Field on the Forced Convective Heat Transfer of Water–Ethylene Glycol-Based Fe3O4 and Fe3O4–MWCNT Nanofluids

“…The proposed method provides more precise results in less time. In addition, Gao et al [44] investigated the thermal conductivity and stability of graphene oxide-Al 2 O 3 hybrid nanofluid. The result showed that the pH, dispersant, ultrasonication power, and duration affect the stability of the hybrid nanofluid.…”