SIMULATION AND WIND TUNNEL TESTING OF A SPECIAL RACKING SYSTEM FOR PV MODULES ON FLAT COMMERCIAL ROOFTOPS

摘要

Every year, more than 2.2GW of commercial photovoltaic (PV) systems are installed worldwide. Approximately 30% of these are mounted on flat rooftops. PV systems that are mounted on flat rooftops have two special requirements: they need to add as little weight as possible to the building and be exposed to as little wind load as possible. The paper analyses the impact of wind on a new racking system developed for PV modules for flat rooftops. Computational Fluid Dynamics (CFD) simulation was used to examine the impacts of wind loads on a rooftop mount system. Wind tunnel testing was also carried out on a model representing this rooftop racking system to further verify the results of the CFD simulation. Testing results indicate that the external section of the PV array will experience a greater wind load compared to its internal section. Calculations performed using the drag coefficient of the Tnnamount Ⅲ D10 racking system demonstrates the advantages of this design under high wind loading. The light weight racking system presents a tilt angle of 10 degrees and includes an optimized wind diffuser to protect the structure against high-wind events. The attributes of robustness and light weight, coupled with its simplicity of installation and packaging make the Trinamount Ⅲ D10 racking system a fast installing, non-penetrative PV mounting system very well suited for applications on flat rooftops.