Dynamic performance analysis of a photovoltaic thermal (PVT) collector with an extruded absorber using python optimization modeling object (Pyomo)

Abstract

Solar photovoltaic thermal (PVT) integrates photovoltaic panels and solar thermal collectors in one system for simultaneous electricity and heat production in a reduced area. The absorber type used for heat extraction significantly affects PVT performance. This work examines the performance of an extruded absorber PVT under varying solar irradiance, ambient temperature, and wind speed. A detailed dynamic mathematical model is developed from energy balance equations and heat transfer correlations for each layer of the PVT collector. Using orthogonal collocation on the finite difference method, the system of differential equations is discretized and solved numerically with Pyomo, a Python optimization modeling tool. Following validation against literature data, the model is used to predict the temperature of each layer and the thermal and electrical output of the PVT collector. The effect of cooling fluid mass flow rate, solar irradiance intensity, ambient temperature, and wind speed on PVT performance is analyzed. This design provides a maximum electrical efficiency of 15.47 % at a wind velocity of 3 m/s, regardless of the cooling fluid flow rate. Peak electrical power of 212.26 W is achieved at the highest flow rate (14.14 kg/hr) and with the highest wind velocity (3 m/s), while the peak thermal power of 348.03 W occurs at a wind velocity of 1 m/s and a flow rate of 11.31 kg/hr. Compared to the conventional sheet-and-tube design at 1 m/s wind speed and 5.65 kg/hr cooling fluid flow rate, the extruded absorber PVT delivers 203.18 W electrical and 189.27 W thermal power, outperforming the 207.46 W electrical and 128.9 W thermal power of the conventional design, demonstrating the potential of the extruded absorber design for enhancing heat generation.