Investigation on influence of antimony tin oxide/silver nanofluid on direct absorption parabolic solar collector

This paper discusses the synthesis and characterization of a novel hybrid nanofluid and its performance analysis on a parabolic trough direct absorption solar collector. Broadening the absorption spectra of working fluid using nanoparticles is the new research revolution for increasing the volumetric solar absorption efficiency. It is reported that plasmonic silver nanoparticles have higher absorption in visible spectra while antimony doped tin oxide has an absorption peak in the near-infrared region. Hence, antimony tin oxide/silver hybrid nanoparticle with broad spectral absorptivity was synthesized. Optimization of the nanofluid composition performed using response surface methodology yielded an optimized mass fraction of antimony tin oxide and surfactant, sodium dodecyl sulfate, as 0.1% each. The solar weighted absorption fraction of optimized nanofluid was obtained as 90.12%. Performance evaluation of the solar collector was based on ASHRAE standards 93-2010. The optical efficiency of the parabolic collector was calculated to be 75%. The maximum thermal efficiency obtained by the optimized nanofluid applied parabolic trough direct absorption solar collector was 63.5% at a flow rate of 0.022 kgs(-1) and the highest exergy efficiency obtained was 5.6%. Thermal and exergy efficiency was observed to increase with increase in flow rate. (C) 2019 Elsevier Ltd. All rights reserved.