The numerical analysis of Al₂O₃[sbnd]Cu/water hybrid nanofluid flow inside the serpentine absorber channel of a PVT; the overall efficiency intelligent forecasting

The improvement of overall efficiency of a PVT solar collector leads to reducing the system's size and cost. The application of single and double serpentine absorber channels in a PVT system was investigated considering the Al₂O₃[sbnd]Cu/water hybrid nanofluid (NF) within the ranges of 0–1% and 500–2000 for the nanoparticle volume fractions (φs) and Res, respectively. The results demonstrated that the double serpentine channel increases the convective heat transfer coefficient, h, and pumping power by 4.36% (or 18.12%) and 10.42% (or 29.78%), respectively, at Re number of 500 (or 2000) within the studied range of φ. The increase in φ from 0% to 1% at a constant Re leads to improving h by 17–25% for both serpentine channels. In addition, the electrical efficiency at different Re numbers improved by 2% and reaches to 15.52% for two configurations as φ escalates from 0% to 0.25% and the further increase in φ is insignificant. However, the thermal efficiencies of the single and double serpentine channels were obtained as 32–38% and 38–43% within the Re range of 500–2000. Moreover, the highest overall efficiency of the single and double serpentine channels were obtained as 84.30% and 90.47% at Re=1000 and φ=1%. Besides, the greatest PEC factor of 1.23 was obtained for the double serpentine channel at Re=1500 and φ=1% followed by PEC of 1.09 for this configuration at Re=1000 and φ=1%. Furthermore, a neural network predictive model was adopted to predict the overall efficiency of the PVT based on the Re and φ and the results showed that the model can predict the overall efficiency with high accuracy.