Photo-thermal characteristics of hybrid nanofluids based on Therminol-55 oil for concentrating solar collectors

Experimental study on thermal conductivity of mono and hybrid Al 2 O 3 –TiO 2 nanofluids for concentrating solar collectors

“…Figure 3 illustrates the homogenous dispersion of Al 2 O 3 and TiO 2 nanoparticles. The uniformity was further established by the SEM and EDAX analysis of hybrid nanopowder 65 …”

“…The literature suggests that hybrid nanofluids are promising heat transfer fluids obtained by doping two or more nanoscopic components for enhancing optical and thermal properties for use in solar collectors 46 . Further Al 2 O 3 ‐based nanofluids are key contributors and cost‐effective in enhancing the thermal conductivity, 60‐63 and TiO 2 is the promising candidate for enhancing the optical properties of nanofluids 64,65 . Fluids utilized in case of solar collectors demand better thermal and optical properties and can be best attained by the synergistic effect of Al 2 O 3 and TiO 2 nanoparticles.…”

“…46 Further Al 2 O 3 -based nanofluids are key contributors and costeffective in enhancing the thermal conductivity, [60][61][62][63] and TiO 2 is the promising candidate for enhancing the optical properties of nanofluids. 64,65 Fluids utilized in case of solar collectors demand better thermal and optical properties and can be best attained by the synergistic effect of Al 2 O 3 and TiO 2 nanoparticles. In our previous work, 65 it was established that the TiO 2 -Therminol-55 nanofluid possesses the maximum absorbance in the visible range of the solar radiations.…”

“…64,65 Fluids utilized in case of solar collectors demand better thermal and optical properties and can be best attained by the synergistic effect of Al 2 O 3 and TiO 2 nanoparticles. In our previous work, 65 it was established that the TiO 2 -Therminol-55 nanofluid possesses the maximum absorbance in the visible range of the solar radiations. Further, it was established that the synergetic effect of Al 2 O 3 and TiO 2 in Therminol-55 enhances the photothermal conversion.…”

“…Also, the viscosity changes are minimum at higher temperatures which further strengthens its candidature for use in solar collectors. 66 As discussed in previous sections, with the aim to assess the feasibility of hybrid nanofluids such as one proposed in our previous studies, 65,66 it is essential to study the effect of design variable such as concentration and operating variable such as temperature on the physical and thermal properties of the HNF, of which thermal conductivity is of prime importance. In this study, an extensive testing protocol has been established and implemented to examine the enhancement of thermal conductivity of Al 2 O 3 -TH-55 NF, TiO 2 -TH-55 NF, and their Al 2 O 3 -TiO 2 -TH-55 HNF.…”