4E study of experimental thermal performance enhancement of flat plate solar collectors using MWCNT, Al2O3, and hybrid MWCNT/ Al2O3 nanofluids

• Published in: Results in engineering 2022-12, Vol.16, p.100723, Article 100723
• Main Authors: Elshazly, Engy, Abdel-Rehim, Ahmed A., El-Mahallawi, Iman
• Format: Article
• Language: English
• Subjects: Exergy; Flat plate solar collector; Heat transfer enhancement; Hybrid nanofluids; Nanofluids; Solar water heater
• ISSN: 2590-1230; 2590-1230
• DOI: 10.1016/j.rineng.2022.100723

Nanofluid is a cutting-edge heat transfer fluid with the potential to significantly improve the heat transfer performance of conventional fluids. The most valued aspects to increase the overall solar collector's effectiveness are to improve design factors and the convection heat transfer coefficient between the absorber tubes and fluid. Water nanofluids including MWCNTs, Al2O3, TiO2, SiO2, and CuO are the most often utilized nanofluids in solar collectors. In this paper, the Flat Plate Solar collector thermal efficiency was experimentally investigated for MWCNT, Al2O3, and hybrid MWCNT/Al2O3 50:50% as a working fluid, under controlled circumstances. The effects of several parameters, including solar radiation intensity, volume proportion of nanoparticles, and volumetric flow rate on the efficiency, are investigated. Four volume concentration percentages were studied for each type of nanofluid (0.5%, 0.025%, 0.01% and 0.005%) with three different mass flow rates for each concentration. The results show that using hybrid MWCNT/Al2O3 (50:50%) offers an increase in efficiency by 26%, 29%, and 18% for 1.5 L/m, 2.5 L/m, and 3.3 L/m, respectively, recommending the replacement of 50% of the MWCNTs by the more economic and environmentally friendly Al2O3. •Solar Heaters efficiency is impacted by nanoparticle thermal properties, concentration, and flow rate of the working fluid.•MWCNT has the highest efficiency improvement results when compared to Al2O3 and hybrid MWCNT/Al2O3 (50:50) nanofluids.•Replacement of 50% of MWCNT nanofluid with Al2O3 provides slightly less efficiency improvement and less environmental hazards.