Energy and exergy assessment of a flat plate solar thermal collector by examine silicon carbide nanofluid: An experimental study for sustainable energy

Abstract

The main reason behind the inefficient performance of heat transfer devices was the use of conventional fluids with poor heat transfer properties. However, remarkable improvement in efficiency was observed in thermal devices when these fluids were replaced by nanofluids with good thermal transfer properties. Various kinds of nanoparticles were used due to their increased thermal conductivity. Such nanofluids are particularly exploited in renewable energy systems like solar collectors. The most frequently used solar collectors in thermal applications are FPSCs. The current experimental research investigates how the use of nanofluids of SiC/DW impact the efficiency of a flat plate solar collector functioning in the climatic environment of Gödöllő, in Hungary. Firstly, the synthesis of nanofluid based on distilled water that contained nanoparticles of SiC (with a size 45–60 nm) at volume fractions of 0.025 %, 0.05 %, 0.075 %, and 0.1 % was performed. Various measurement instruments were used to test the thermophysical characteristics and stability. In the subsequent stage, thermal and exergy efficiencies tests were conducted on the solar collector with a range of mass flow rates including 0.025, 0.033, and 0.041 kg/s in which the collector’s efficiency was calculated according to the ASHRAE standard 93–2003. This developed collector was subjected to different flow rates, and nanoparticle concentrations to find out the effect of nanofluids on the thermal and exergy efficiencies of the solar collector. The findings indicated that an increase of up to 30.3 % was achieved in the fluid’s thermal conductivity through the addition of nanoparticles of SiC. The collector’s thermal efficiency was maximised at 77.43 % when the value of [(Ti – Ta)/GT] was zero for a volume fraction (φ) of 0.1 % and mass flow rate of 0.041 kg/s, which represented a 35.53 % increase over the base liquid. Additionally, an increase of 37.4 % was recorded for the exergy efficiency at volume fraction (φ) of 0.1 % than its value in distilled water. Ultimately, the heat transfer properties of the device showed improvement.