A Ducted Photovoltaic Façade Unit with Buoyancy Cooling: Part II CFD Simulation

Abstract

A ducted photovoltaic façade (DPV) unit was simulated using computational fluid dynamics (CFD). This is Part II of the study, which is a repetition of Part I-a previous experimental study of the ducted photovoltaic unit with buoyancy cooling. The aim of this study is to optimize the duct width behind the solar cells to allow for the cells to achieve maximum buoyancy-driven cooling during operation. Duct widths from 5 to 50 cm were simulated. A duct width of 40 cm allowed for the maximum calculated heat to be removed from the duct; however, the lowest celloperating temperature was reported for a duct width of 50 cm. The results showed that the change in temperature (∆T) between the ducts' inlets and outlets ranged from 8.10 to 19.32 • C. The ducted system enhanced module efficiency by 12.69% by reducing the photovoltaic façade (PV) temperature by 27 • C from 100 to 73 • C, as opposed to the increased temperatures that have been reported when fixing the PV directly onto the building fabric. The maximum simulated heat recovered from the ducted PV system was 529 W. This was 47.98% of the incident radiation in the test. The total summation of heat recovered and the power enhanced by the ducted system was 61.67%. The nature of airflow inside the duct was explored and visualized by reference to the Grashof number (Gr) and CFD simulations, respectively.