An experimental study on evacuated tube solar collector using nanofluids

The present study aims to investigate the energy efficiency of an evacuated tube solar collector containing water based single walled carbon nanotube nanofluids. The effect of various parameters such as volume concentration of nanofluid, inlet and outlet fluid temperature, solar radiation and ambient temperature on the collector efficiency is investigated. According to the results, higher efficiency is achieved for higher volume concentration of single walled carbon nanotube nanofluids. The energy efficiency also increased with increasing solar radiation value. The highest collector efficiencies are observed for 84.24% and 94.73% using 0.05 and 0.25 vol% single walled carbon nanotube nanofluids respectively at a mass flow rate of 1.5kg/min