Study On Semi-submersible Tidal Current Power Station System Performance

Tidal power is a kind of renewable energy with high value and potential in use, which should take an important position in the society nowadays when fresh energy is greatly developed. Our country has a long coastline which is rich in tidal energy offshore with a good exploitation prospect.At present, the already running station examples in the world have several basic forms, such as floating structures, suspended structures, seabed piled structures and sit seabed structures, selecting a special carrier with hydraulic turbine and generating units. The domestic experimental 70kW and 40kW power stations of HRBEU use the floating structure and sit seabed structures. For the terrible working condition, the designing of structure and mooring system to ensure the station safe and reliable is the key to develop the commercial using of tidal power.The work which the article carries out is a kind of exploration about semi-submersible tidal current power station system design. The power station includes blades, carrier platform with generator, stabilization system and mooring system. This thesis has three parts: first, studying on the whole power station designing and system composition by stabilization and buoyancy calculation to choose the best design. Then base on the 3-D potential theory, first-order forces and moments, first-order motion and second-order draft forces under different wave headings are calculated by the software of HydroStar. And the problems which must be noticed have been put forward by analysis on above results. Last, according to the power station characteristic and the mooring line ingredient proportion's difference, three schemes about mooring lines are presented. We give the forces and the result of movement about different mooring lines by using time domain analysis under different conditions with ARIANE7. On this basis, we give the optimum scheme. Finally, we select anchor base on seabed and berthing factors.The thesis results show that semi-submersible tidal current power station system design has good ability of resisting wind and wave, and also has good movement performance. It can be further studied as preferential design.