The study of heat control on PVT modules with a new leaf-like heat exchanger

Abstract

The photovoltaic/thermal (PVT) collector is an eco-friendly technology that simultaneously converts solar energy into electrical and thermal energy. However, a high solar cell temperature seriously affects the electrical efficiency of the PVT collector, which is an urgent problem that needs to be addressed. Some traditional cooling technologies for PVT collectors were previously investigated, but they were inefficient in heat collecting performance. In addition, a nonuniform solar cell temperature distribution accelerates the aging of PVT modules, and this topic has only rarely been discussed. In the present study, a new leaf-like heat exchanger based on bionics was proposed to improve heat control of the PVT collector. A three-dimensional mathematical model was developed in COMSOL and validated by comparing modeling results with experimental data already available in the literature. The effect of different operating conditions on the performance of the new PVT collector was investigated. The results of this study show that the bifurcation angle of the leaf-like heat exchanger with a symmetrical configuration between 20° and 35° was characterized by a lower and more uniform temperature distribution on solar cells in comparison with conventional heat exchangers. Moreover, the average temperature of the solar cell cooled by the new leaf-like heat exchanger decreased by 5.31 °C, and the pressure drop associated with the leaf-like heat exchanger was only half the value of the pressure drop associated with a conventional heat exchanger at a mass flow rate of 0.0314 kg/s. Finally, the total efficiency of the new PVT collector was 4.36% higher than that of the conventional PVT collector.