An experimental investigation on the simultaneous effect of CuO–H2O nanofluid and receiver helical pipe on the thermal efficiency of a cylindrical solar collector

In this paper a cylindrical solar collector with receiver helical pipe is designed and manufactured. The experimental research is carried out to investigate the thermal performance of this solar collector using distilled water and CuO–H2O nanofluid as working fluids based on ASHRAE standard in collector testing. The effects of mass flow rate of fluid, nanoparticle mass concentration and SDS (sodium dodecyl sulfonate) as surfactant on the efficiency of this cylindrical solar collector are investigated and discussed. In the experiments, the mass flow rate of fluid change from 0.0083 to 0.033 kg/s and the weight fraction of nanoparticles are 0.1%, 0.2% and 0.4%. Results show that using water-based CuO nanofluids can significantly enhance the efficiency compared with pure water. For 0.1 wt% nanofluid in 0.0083 kg/s mass flow rate of fluid the maximum thermal efficiency is increased 25.6%. Also, with the use of nanofluid with SDS as surfactant the maximum collector efficiency is increased by 24.2% compared with the case without surfactant.