Novel conceptual design and performance analysis of a semi-submersible platform for 22 MW floating offshore wind turbine

Abstract

This research presents the conceptual design and performance analysis of a large-scale semi-submersible floating offshore wind turbine platform, named DUT-Semi, which features a simple and compact structural layout. It is specifically designed to address the enhanced demands for stability and hydrodynamic performance arising from the enlarged hub height and rotor diameter of the IEA 22 MW wind turbine. The DUT-Semi incorporates several innovations on structural layout, including cylindrical pontoons arranged in a T-shape for adequate displacement, Co-pontoons that ensure smooth transitions between side columns and pontoons, and Base plate structure for simplifying main column installation. These innovations aim to ensure motion performance while reducing construction costs and enhancing structural safety. To prevent excessive redundancy in DUT-semi design, this study compares and examines its stability and hydrodynamic response against another floating platform. The results demonstrate the reliability of DUT-semi across all six degrees of freedoms, even under coupled extreme loading conditions, including a 50-year wind event. Mooring line tension analysis also highlights the advantages of the proposed cost-effective mooring system in distributing tension and enhancing mooring safety. These design innovations offer reference for the future commercial design of floating platforms and mooring systems in the realm of offshore wind energy.