The entropy generation analysis and optimization of a water/silver nanofluid flow inside a photovoltaic thermal collector considering plain, ribbed, and porous-ribbed absorber tubes

Abstract

BackgroundThe application of three (a) plain, (b) ribbed and (c) porous-ribbed absorber tube in a PVT solar collector was numerically investigated from the second law of thermodynamic points of view. MethodsThe 3-D laminar forced convection numerical analysis and optimization were performed for Res of 500–2000 and considering water/silver NF with the nanoparticle concentration ratios of 0–2%. Significant findingsThe results showed that the lowest thermal entropy generation rate (S˙th) is associated with the porous-ribbed configuration which is nearly 323% (or 253%) and 1211% (or 1059%) lower as compared to the plain (or ribbed) absorber tube. The moderate frictional entropy generation rate (S˙fr) was obtained for the porous-ribbed configuration which was 23.45% higher and 14.50% lower than that for the plain and ribbed tubes, respectively. The thermal exergy efficiency for the PVT with the porous-ribbed tube was nearly 50% and 46% higher than that with the plain and ribbed absorber tubes, respectively. However, the electrical exergy efficiency of the PVT with the porous-ribbed tube were superior to the ribbed and plain tubes only at low Res of 500 and 1000, while a reverse trend was obtained for the higher Res.