Performance Evaluation of Linear Solar Collector Using …
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Fig. 2 SEM image of a TiO 2 nanoparticle and b CuO nanoparticle
3 Results and Discussion
3.1 Morphology of Nano Particles
Figure 2 shows the results of the morphological analysis. The TiO 2 and CuO nanoparticles exhibited a homogenous morphology, and the particle size was found to be 73.2
and 86.4 nm in that order. Stability of the nanofluid was quantified using the zeta
potential analyzer and was found to be −28.54 mV. Moreover, as per the reports of
Yu and Xuan [12] for the flow application, the stability is of less importance due to
the flow stirring of the nanofluid.
3.2 Optical Study
Transmittance spectrum of the nano-CuO and -TiO 2 heat transfer fluid and ethylene glycol was taken to estimate the optical absorptivity. The results revealed that
0.02% volume concentration of CuO and 0.025% volume concentration of TiO 2 had
maximum optical absorptivity, and the hybrid nanofluid was prepared according to
these concentrations. Absorbance of the nanoheat transfer fluid increased with the
concentration of CuO in it which was attributed to the direct absorption of radiation.
The maximum absorbance was noted in the visible region of the spectrum, and it is
increased with nanoparticle concentration. Figure 3 shows the transmittance spectra
of 0.02% CuO, 0.025% TiO 2 , and ethylene glycol.
469
Fig. 2 SEM image of a TiO 2 nanoparticle and b CuO nanoparticle
3 Results and Discussion
3.1 Morphology of Nano Particles
Figure 2 shows the results of the morphological analysis. The TiO 2 and CuO nanoparticles exhibited a homogenous morphology, and the particle size was found to be 73.2
and 86.4 nm in that order. Stability of the nanofluid was quantified using the zeta
potential analyzer and was found to be −28.54 mV. Moreover, as per the reports of
Yu and Xuan [12] for the flow application, the stability is of less importance due to
the flow stirring of the nanofluid.
3.2 Optical Study
Transmittance spectrum of the nano-CuO and -TiO 2 heat transfer fluid and ethylene glycol was taken to estimate the optical absorptivity. The results revealed that
0.02% volume concentration of CuO and 0.025% volume concentration of TiO 2 had
maximum optical absorptivity, and the hybrid nanofluid was prepared according to
these concentrations. Absorbance of the nanoheat transfer fluid increased with the
concentration of CuO in it which was attributed to the direct absorption of radiation.
The maximum absorbance was noted in the visible region of the spectrum, and it is
increased with nanoparticle concentration. Figure 3 shows the transmittance spectra
of 0.02% CuO, 0.025% TiO 2 , and ethylene glycol.