Thermal Absorption Performance Evaluation of Water-Based Nanofluids (CNTs, Cu, and Al2O3) for Solar Thermal Harvesting

Abstract

For solar thermal harvesting, an experimental study was performed on the thermal absorption performance of water-based carbon nanotubes (CNTs), Cu, and Al2O3 nanofluids using a halogen lamp-based thermal radiation system. The effect of nanoparticle concentrations (0.01 wt.%, 0.1 wt.%, and 1 wt.%) on the nanofluid dispersion, stability, and thermal absorption characteristics was investigated, and a comparative analysis was performed for each type of nanofluid. All types of nanofluids increased the absorbance and electrical conductivity with increasing nanoparticle concentration, which contributed to improving the thermal absorption performance of nanofluids. The results showed that the thermal absorption performance was high in the order of carbon-based nanofluids (CNTs), metal-based nanofluids (Cu), and oxide-based nanofluids (Al2O3). In CNTs nanofluids, the thermal absorption performance expressed the time reduction rate, which was 12.8%, 16.3%, and 16.4% at 0.01 wt.%, 0.1 wt.%, and 1 wt.% test cases, respectively. Therefore, the 0.1 wt.%-CNTs nanofluid is more economical and appropriate. However, in Al2O3 nanofluids, the time reduction rate of the 1 wt.% nanofluid was significantly higher than that of the 0.01 wt.% and 0.1 wt.% nanofluids. In Cu nanofluids, unlike CNTs and Al2O3 nanofluids, the time reduction rate constantly increased as the nanoparticle concentration increased.

Optimization of AL₂O₃ Concentration In Water Based Nano Fluid To Enhance The Heat Transfer For Solar Application

“…Ansyss Fluent software used to carry out the simulation for different concentration particularly for 20 nm sized Al 2 O 3 nano particles and results were tabulated and compared to theoretical values with heat transfer coefficient and Nusselt number. Youngho Lee et al (2021), show that dispersion characteristics of oxide based nano-fluids Al 2 O 3 having high absorbance values with respect to the concentration for solar application, in his investigation thermal absorption increases for the concentration 0.01, 0.1%, 1% by weight. Kong and Lee (2020), investigated the thermal performances of Al 2 O 3 nano particles in water using circular tube under turbulence with three different concentrations and found that thermal conductivity and heat transfer coefficient of nano-fluid increased with increase in concentration in extend to this, he also shows that Nusselt number increases for Reynolds number 4000 to 24000.…”

Recent Developments on the Thermal Properties, Stability and Applications of Nanofluids in Machining, Solar Energy and Biomedicine

“…The thermal absorption performance of nanofluids is another important characteristic of this colloidal mixture. Recently [114], an experimental study was performed to evaluate the thermal absorption performance of nanofluids of carbon nanotubes, Cu, and Al 2 O 3 using water with base fluid. The authors show that all nanofluids increased the absorbance and electrical conductivity with increasing nanoparticle concentration, which has improved the thermal absorption performance of nanofluids.…”