Thermal analysis on the performance of a finned hybrid bi-fluid PVT system

Abstract

The increase in the temperature of solar panels is a significant issue that leads to low performance of photovoltaic (PV) cells. This numerical investigation aims to perform a transient analysis employing commercial computational fluid dynamics code and improve the electrical energy of the PV panel in a hybrid system by utilizing both water and air and adding fins. The system was cooled from the rear side of the PV/thermal (PVT) module by flowing water at different mass flow rates (ṁw = 0.010 kg/s to 0.020 kg/s) through aluminum tubes adhered to an aluminum absorbent plate. Moreover, the air passes through the channel that contains aluminum fins welded to the absorbent plate and next to the tubes. The objective is to analyze the effects of ṁw and fins on the flow and the thermal efficiency. A comparison was made between two modules of bi-fluid (BF) PVT manifolds: module 1 without fins and module 2 with fins. The effect of the operating temperature rise on the PV panel and the total thermal efficiency was evaluated. The attained results presented a linear decrease in thermal efficiency with the increase of ṁw. The thermal efficiency of modules 1 and 2 at ṁw = 0.010 kg/s is 50% and 60%, respectively. Under the solar irradiance and ṁw = 0.010 kg/s in module 2, an improvement of thermal efficiency of about 5.7% was recorded compared to module 1. The hybrid PVT BF system with fins (module 2) operating with ṁw = 0.010 kg/s has proved that adding fins to the PVT system was very effective in maintaining the system’s thermal efficiency at its highest record.