Energies (Feb 2022)

Hybrid Nanofluid in a Direct Absorption Solar Collector: Magnetite vs. Carbon Nanotubes Compete for Thermal Performance

  • Pavel G. Struchalin,
  • Dmitrii M. Kuzmenkov,
  • Vladimir S. Yunin,
  • Xinzhi Wang,
  • Yurong He,
  • Boris V. Balakin

DOI
https://doi.org/10.3390/en15051604
Journal volume & issue
Vol. 15, no. 5
p. 1604

Abstract

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The paper presents the experimental measurements of thermal efficiency of a tubular direct absorption solar collector (DASC) with a hybrid nanofluid based on magnetite (Fe3O4) and multi-walled carbon nanotubes (MWCNT). The volumetric concentration of Fe3O4 and MWCNT was 0.0053% and 0.0045%, respectively. The experiments were carried out for the flow rates of 2–10 L/min and a temperature difference up to 20 ∘C between the environment and the DASC. The performance of the DASC with a hybrid nanofluid was in the range of 52.3–69.4%, which was just beyond the performance of the collector with surface absorption. It was also found that using a MWCNT-based nanofluid with an equivalent total volumetric concentration of particles (0.0091%), the efficiency was 8.3–31.5% higher than for the cases with the hybrid nanofluid.

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