Design And Performance Research Of The Eccentric Vertical-axis Variable-pitch Turbine For Tidal Current Energy Conversion

The development and utilization of rich tidal current energy which is renewable energycan alleviate world energy crisis and reduce damage to the ecology, and this receives abroadattention and research. The vertical axis turbine as the tidal current energy conversion device,is not easy to self-start and energy capture efficiency is not high when the flow speed isdifferent. In order to improve its self-starting performance and energy capture efficiency, avariable-pitch turbine which provides technical support to improve generation efficiency isdesigned.Based on the analysis of variable-pitch theory, the eccentric variable-pitch mechanism onthe basis of oldham coupling is taken as the basic principle plan. The program design isfinished and the freedom of variable-pitch mechanism is analyzed. Then the design of theturbine structure is finished and its3D model with Pro/E software is established. Last,kinematic analysis and simulation of the variable-pitch mechanism are carried out and therationality of the eccentric variable-pitch mechanism’s design is verified.The important hydrodynamic performance parameters such as pitch angle, attack angleand energy capture efficiency can be obtained through the analysis of force and movement.Lateral induced velocity coefficient can be calculated by momentum theorem. MATLABproprams to calculate induced velocity coefficient, declination, energy capture efficiency andother related hydrodynamic parameters are compiled. At last the design of graphical userinterface of kinematic analysis and simulation of the turbine is finished. The analysis aboveshows that the variable-pitch turbine has higher energy capture efficiency.Prototype model of the eccentric vertical-axis variable-pitch turbine for tidal currentenergy conversion is developed amd experimental study of the prototype is finished. Thenexperimental results such as energy utilization are obtained and show that energy utilization ishigh in different flow velocity. The results have demonstrated that variable pitch turbine hasbetter starting performance and higher energy capture efficiency.The vertical-axis variable-pitch turbine can achieve continuous and smooth workingperformance, good self-starting performance and higher energy capture efficiency. Besides,the turbine is economical and practical, particularly suitable for the areas of shortage in electricity supply such as offshore, remote island and rivers. The turbine will have greatmarket potential and promotion prospects.