Performance enhancement of photovoltaic solar collector using fins and bi-fluid: Thermal efficiency study

This work exhibits a three-dimensional numerical investigation of a solar collector Photovoltaic Thermal (PV/T) bi-fluid based on the use of dual exchangers cooling with both water and air simultaneously. The effect of the absorber plate design and water mass flow rate (mf) of water and natural airflow has been studied according to the fins added to the system, which mainly includes a flat plate of aluminum attached to the tubes of aluminum. The objective is to analyze the effects of water mf fluctuating between 0.01 and 0.02 kg/s, fins location and number (from 20 to 40 fins), and changing solar irradiation values (100 to 1050 W/m2) on the flow structure and thermal efficiency of photovoltaic solar cells. The hybrid collectors studied are made of monocrystalline photovoltaic cells and an absorber plate of aluminum in the lower of the PV module. An evaluation was made between three configurations of bi-fluid (air and water) PV/T manifolds according to the number of fins. The first configuration is a hybrid PV/T system containing tubes without fins. The second configuration is a hybrid PV/T system containing tubes attached with 20 fins. The third configuration is a hybrid PV/T system containing tubes attached with 40 fins. The results confirm that the thermal efficiency of the PV/T system using (water and air) as a working fluid increase with increasing the number of fins (from 20 to 40 fins) and with increasing solar radiation (100 to 1050 W/m2), but it decreases a little with increasing mf of water (0.01 to 0.02 kg/s) by about 1.1%. For the mf of water equal to 0.01 kg/s, the thermal efficiency of the PVT system configurations 1, 2, and 3 are equal to 50.54%, 52.33%, and 54.25%, respectively. The optimal design for good cooling of the photovoltaic cells and higher yields of the hybrid collector is the third configuration with a water mf of 0.01 kg/s.