Performance enhancement of a solar powered air conditioning system using passive techniques and SWCNT /R-407c nano refrigerant

• Main Authors: Shek Rahman, Salah Issa, Zafar Said, Mamdouh El Haj Assad, Rashed Zadeh, Yazan Barani
• Format: Article
• Language: English
• Published: Elsevier 2019-12-01
• Series: Case Studies in Thermal Engineering
• Online Access: http://www.sciencedirect.com/science/article/pii/S2214157X19302953

This work presents a novel solar powered air-conditioning system that operates under UAE climate conditions. Distinct passive techniques and refrigerant-based nanofluids, termed as ‘‘Nano refrigerants’’ were investigated to enhance the system performance. Results suggest that the proposed design of using passive techniques such as: roofing reflective material, trees, double-glazed windows, and overhang, reduces the space cooling load by 31.5%. Nano refrigerants effect on the coefficient of performance (COP) resulted in improving COP by adding of 5 vol % single wall carbon nanotube (SWCNT) into R407c refrigerant at temperatures of 283–308 (K). The results indicate that the thermal conductivity of SWCNT/R-407c nano refrigerant increased by about 15.6% compared to the base refrigerant (R-407c) at 305 K. The usage of nano refrigerant reduces consumption of compressor work by 4%. Furthermore, SWCNT/R-407c nanorefrigerant shows the notable improvement of COP of at about 17.02% for thermal conductivity and at about 10.06% for specific heat, respectively compared to R-407c refrigerant. Finally, comparisons between the proposed design and the conventional system as well as with previous literature. Results demonstrate that the proposed system reduces the compressor work by 34% and the COP is increased by 4.59% compared to the conventional air-conditioning system. Keywords: Nanoparticle, Nanorefrigerent, Solar energy, Passive technique, HVAC system, COP