Experimental study of using nano-(GNP, MWCNT, and SWCNT)/water to investigate the performance of a PVT module Energy and exergy analysis

In this paper, the effects of using carbon-based nanofillers/water nanofluids as a coolant fluid in a photovoltaic thermal system from both energy and exergy viewpoints are experimentally presented. The considered nanoparticles including MWCNTs, SWCNTs, and GNPs are dispersed in deionized water as the base fluid by 0.05 mass%. The experiments are carried out on certain days in August and September at Ferdowsi University of Mashhad, Mashhad, Iran. In order to investigate the consistency of the results, an uncertainty of the experiments is examined. The various mass flow rates are investigated in all cases, and as a result, an optimum mass flow rate of 50 kg h(-1) based on first and second laws of thermodynamics is selected. According to the results, employing GNP/water, SWCNT/water, and MWCNT/water increase the total average overall energy efficiency by 19.3%, 15.24%, and 9.46% in comparison with pure water, respectively. Additionally, GNP/water, SWCNT/water, and MWCNT/water reduce the total average entropy generation of the module by 2.88%, 1.23%, and 0.82% compared to the pure water, respectively. It has been found that implementation of GNP/water nanofluid leads to more improvement in the module performance among other coolant fluids.