Hybrid nanofluids multi performance optimizations for the cooling system coupling with hybrid photovoltaic thermal collectors

Hybrid photovoltaic thermal (PVT) collectors have assumed considerable importance for their dual-energy applicability which is presented in thermal and electrical form. The thermal behavior of the hybrid collector plays an ameliorative role in dissipating the heat generated in the cell, and this increases the electrical efficiency accordingly with the help of a coolant fluid (nanofluids). The contribution of this study is to evaluate the potential interest of nanofluids in the cooling system of a photovoltaic thermal system (PVT) by modeling and comparing the thermal conductivity of TiO2-water, Cu-water nanofluids and of TiO2/Cu-water hybrid nanofluid, also their thermal capacity and viscosity. Programs have been developed with volume concentrations from 0% to 4% and from 0% to 10% with constant temperature and nanoparticles diameter. The results show that all thermophysical properties characterizing the heat transfer are more important in a hybrid nanofluid compared to the simple nanofluid, such us for a nanoparticle volume fraction of 3%, the thermal conductivity and thermal capacity increased by 32% and 0.23% respectively, for a volume fraction range of 0 to 10%, while they show an increase of 12% and 0.22% respectively, for a range of 0 to 4%. Eventually the model agreed with experimental results.