Analyzing the effect of confined jet impingement on efficiency of photovoltaic thermal solar unit equipped with thermoelectric generator in existence of hybrid nanofluid

Solar irradiation (G) is converted into thermal and electrical power using photovoltaic/thermal (PVT) systems. Maintaining Photovoltaic (PV) cells temperature within the permissible temperature range is crucial for PV cells' thermal control because it improves the overall performance and prevents solar cells damage. In this numerical work, a novel method for cooling of the PV unit has been presented. The PV panel is combined with a thermoelectric (TE) generator and the cooling system consists of the heat transfer tube (HTT) integrated with confined jet impingement (CJI) heat sink. ND-Co3O4 hybrid nano-powders with the mass concentration of 0.05%, 0.1%, and 0.15% were mixed with water as cooling fluid. As the constant operating conditions, the ambient and cooling fluid inlet temperatures are set as 30Cand 27 C, respectively, and wind velocity is 1 m/s. Three different inlet velocities were investigated for both the fluid inside the HTT (0.007, 0.07, 0.13 m/s) and the fluid which enters the CJI (0.4, 0.7, 1 m/s). Different amounts of solar irradiation (G = 560-5000 W/m2) were applied and the optimum solar irradiation is determined according to the critical PV module temperature (TPV). The best obtained system have electrical and thermal performances of about 84% and 15.44%, at the solar irradiation of 760 W/m(2), tube inlet velocity of 0.13 m/s (Re = 1676), and CJI inlet velocity of 1 m/s (Re = 1611), using NDCo3O4 hybrid nanofluid with mass concentration of 0.05%. Compared to G = 560 W/m2, the relative PV, TE, and thermal powers are 7.6, 67.1, and 11, respectively, in the optimized case at maximum value of G (5000 W/m(2)).