Thermal performance analysis of a parabolic trough collector using water-based green-synthesized nanofluids

• Published in: Solar energy 2018-08, Vol.170, p.658-670
• Main Authors: Okonkwo, Eric C., Essien, Edidiong A., Akhayere, Evidence, Abid, Muhammad, Kavaz, Doga, Ratlamwala, Tahir A.H.
• Format: Article
• Language: English
• Subjects: Agricultural wastes; Barley; Corrosion inhibitors; Green-synthesis; Heat transfer; Heat transfer coefficients; Mathematical models; Nanofluids; Nanoparticles; Parabolic trough collector; Performance evaluation; Pressure loss; Silica; Silicon dioxide; Solar collectors; Solar energy; Synthesis; Thermal energy; Thermal enhancement; Thermodynamic efficiency; Titanium dioxide
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/j.solener.2018.06.012

•Heat transfer enhancement in a PTC using 2 new green-synthesized nanofluids.•The nanoparticles were efficient corrosion inhibitor, non-toxic and cheap.•OLE-TiO2 produced 128% enhancement in heat transfer coefficient.•BH-SiO2 produced 138% enhancement in heat transfer coefficient. The parabolic trough collector (PTC) is one of the most advanced solar concentrating technology available. The study employed experimental synthesis and numerical modeling to present possible solutions to the challenges of nanofluids application in solar collectors. A green alternative of using nanoparticles synthesized from green bio-matter (Olive leaf extract OLE) and agricultural waste (barley husk BH) is proposed. The synthesized nanoparticles were characterized using analytical and morphological techniques and were found to be efficient corrosion inhibitor, non-toxic and cheap to produce when compared to the conventional ones. The study presents an innovative thermal performance evaluation of a parabolic trough collector operating with green-synthesized nanofluids: water/BH-SiO2 and water/OLE-TiO2. The model of the PTC was developed on the engineering equation solver (EES) and validated using the experimental results of the Sandia National Laboratory (SNL), AZTRAK platform LS-2 test. The results of the analysis show that a 0.073% mean enhancement in the thermal efficiency is observed with the use of water/BH-SiO2 nanofluids and 0.077% mean enhancement with the use of water/OLE-TiO2 nanofluids. The heat transfer performance of the nanofluids shows a mean enhancement in heat transfer coefficient of 128% and 138% for water/OLE-TiO2 and water/BH-SiO2 nanofluids respectively. The mean variation in pressure losses between the nanofluids and base fluid was also observed to be less than 14.85% at a 3% volumetric fraction of nanoparticles.