Performance Optimization of Water-Based Pvt Collector with Dual Tanks: A Staircase Cooling Method

Abstract

The photovoltaic/thermal (PVT) collector, which integrates photovoltaic and solar thermal technology, offers an innovative solution for full-spectrum solar energy utilization. A dual-tank water system structure is proposed in this study to achieve staircase cooling for PVT modules with the graphite-embedded structure. The thermal and electrical performances of various comparative modules are experimentally analyzed under outdoor conditions in Beijing. The results show that the dual-tank system reduces the average cell layer temperature by 12.3°C under the radiation intensity of 572 W/m2, resulting in a relative increase in electrical efficiency of 8.2% compared to the PV module. Additionally, the graphite-embedded PVT module achieved a daily average thermal efficiency of 34.41%, corresponding to a 57.1% improvement over the tube-and-sheet module of 21.34% under the 458W/m2 radiation condition. Furtherly, the whale algorithm is employed to determine the optimal dual-tank volume for 30 operating conditions during the experiment. The optimized dual-tank configuration achieves a relative increase in daily energy output of 5-20% compared to a fixed-volume tank. Moreover, a third-order polynomial model is established between the optimal tank volume and radiation. This study can provide a reference for structural optimization of PVT collectors and a feasible practice for enhancing solar energy utilization.

Keywords: PV/T collector, Graphite-embedded structure, Machine learning algorithm, Whale optimization algorithm