Numerical analysis on efficiency improvement of solar photovoltaic and thermal hybrid system

Abstract

The depletion of traditional energy sources and the increasing demand for energy due to climate change has raised concerns among researchers worldwide. Solar energy, specifically photovoltaic thermal (PVT) systems, has the potential to become a major source of renewable energy for our planet. However, more research is necessary to optimize the performance, efficiency, and cost-effectiveness of PVT systems. This study examines a 3D solar photovoltaic and thermal hybrid system that utilizes air as a working fluid with six fins inside the heat exchanger. The heat exchanger's enclosure is constructed from corrosion-resistant stainless steel, and the heat exchanger's exposed surfaces are insulated with glass wool. The fins are manually circulated air, and the channels are made of aluminum, while an aluminum sheet with a thickness of 1 mm serves as the heat exchange component. The fins' top side is bent and firmly attached to the lower back floor of the solar photovoltaic (PV) panel to allow heat transfer from the PV panel to fins via the conduction technique. The study selected solar irradiation, inlet fluid mass flow rate, and inflow temperature between (250 - 500 W/m2), (0.015-0.5 Kg/s), and (10-40°C), respectively, based on Bangladesh's weather conditions. The study applied the finite element method (FEM) to solve heat transfer equations for PV layers, including glass, cells, fins, heat exchangers, and laminar flow equations for the fluid domain. The results indicate that a 50 W/m2 increase in solar irradiation leads to a decrease of approximately 0.404% in overall efficiencies, while a 0.097 Kg/s increase in mass flow rate results in a 6.994% increase in overall efficiencies. Furthermore, a 5°C increase in inflow temperature leads to an overall efficiency increase of 0.33%. Hence, this study's findings could help researchers better comprehend air's properties as a heat exchanger in a developed design and they can be applied to government and commercial projects.