An experimental assessment of the thermal performance of an evacuated tube solar collector by using Cu nano-fluid Available to Purchase

This article investigated the effect of nanoparticles (Cu/DW) on the thermal performance of a solar vacuum collector, as nanofluids are characterized by high thermic conductivity. The Cu nanoparticles used had a diameter of 30 nm with three different volume fractions of 1,3 and 5% vol nanoparticles examined at different flow rates of 30, 50, and 60 L/min. The tests were conducted in the city of Baghdad, Iraq, at a longitude of 44° 14′ E and latitude of 33° 33′ N. The results presented that the volumetric fraction of 5 vol% nanoparticles at a flow rate of 60 L/min achieves the maximum useful heat gain. The data showed that adding more nanoparticles improved the thermal efficiency of the evacuated solar tube. The improvement results of ETSC at a flow rate of 60 L/min increase to 19.69% for the volume fraction of nanoparticles of 5% vol. In contrast, the improvement rate of distilled water was 4.03% for the same flow assessment. According to the findings, the temperature difference and absorbed energy increased when nanoparticles were used.