Parametric Investigation of Nano-Fluids Utilization in Parabolic Trough Collector

In this experimental work, using nanofluids and water on the thermal performance of the two prismatic parabolic trough collectors (PTC) has been compared in the two prismatic PTC. Those prismatic PTCs installed side by side have been examined simultaneously for different days; this ensures that the comparison was conducted under identical conditions, one for the distilled water and the other for the proposed nanofluid. The proposed nanofluid that was utilized in our study has been produced by dispersing nanoparticles of Multi-walled carbon nanotubes (MWCNT) in a distilled water with a weight concentration of 0.1%. The key results showed that adding nanoparticles' positive impact increasing the base fluid's thermophysical properties (Water), side by side with enhancing the heat transfer between the receiver tube and the working fluid. The average thermal efficiency of the PTC that used the proposed nanofluid showed a higher average value in comparison with the other PTC that used base fluid at the same weather conditions (ambient temperatures and solar irradiances). The tests were conducted for two different weather conditions; for the first set of experiments, the average thermal efficiencies observed were: 62.9% for nanofluid with 0.1% wt fraction and 33.4% for water. While for the second set, the average efficiencies obtained were: 60.45% for Nanofluid with 0.1% volume fraction and 32.2% for water. Finally, it was found that the average thermal efficiency of utilizing nanofluids had a strong dependence on the settling time after sonication, side by side with using the surfactant, where the highest average thermal efficiency was obtained immediately after sonication and utilizing Arabic Gum as a surfactant.