Energy, economic and environmental investigation of a flat plate solar collector with CeO2/water nanofluid

In the present study, the energy, economic and environmental analysis are investigated for a flat plate solar collector with 100 LPD forced circulation system using water and CeO2/water nanofluid as the working fluids. The investigation is performed on different volume flow rates ranging from 1 to 3 L min(-1) and varying the volume concentration of CeO2/water nanofluid from 0.01 to 0.1%. Due to the enhanced thermophysical properties of the small amount of CeO2 nanofluid, the system achieved maximum heat transfer coefficient as well as higher energy and exergy efficiencies than water as working fluids. It is found that the efficiency of solar collector is 28.07% more than that of water while using CeO2/water nanofluid as the working fluid with the volume concentration of 0.05% and the volume flow rate of 2 L min(-1). The result of second law analysis indicates that the system using nanofluid and operating with 0.05% volume concentration has shown maximum exergy enhancement of 5.8%, lowest entropy generation and maximum Bejan number when compared with other volume concentrations. Apart from that a reduction of 24.52% collector area is achieved for flat plate solar collector using CeO2/water nanofluid when compared with conventional solar water collector for the same capacity. It is evaluated that CeO2/water nanofluid in flat plate solar water collector saved 300.2 MJ of embodied energy, offsetting emission of 175 kg less CO2 and has a higher payback time of 2.12 years than a traditional solar water collector.