| Tidal energy is a kind of renewable energy with large reserves,high energy density and sustainable development in China.The main application is power generation,meanwhile the turbine is vital for the whole power generation system.The energy acquisition efficiency of the turbine directly determines the power of the captured energy of the turbine.The current velocity in most of the waters in China is low,so it is of practical significance to develop a turbine with high energy efficiency and wide flow rate.In this dissertation,the prototype and experimental test platform of the Half-rotating Impeller Tidal Turbine with Double Blades(HRITT-DB)were designed and manufactured.The hydrodynamic performance of the HRITT-DB was tested through the experiment,which provided the experimental data support for the subsequent engineering promotion of the HRITT.Firstly,the working principle of the half rotating mechanism and the half rotating impeller turbine was introduced,and the movement track of the blade was analyzed.Based on the blade element theory and the disk flow tube model,the force on the blade of the half rotating impeller turbine was analyzed.The difference between the half rotating impeller turbine and other types of turbine was that the blade rotated at the same time of revolution,so the angle of attack of the relative inflow was not only related to the inflow and the speed of the blade,but also related to the chord length of the blade.The hydrodynamic calculation model of the HRITT-DB was established.Secondly,a prototype of the HRITT tested easily was designed and manufactured.Based on the theoretical research of the turbine in the early stage,XFlow fluid simulation software was used to analyze the blade shape.The prototype of the HRITT-DB was manufactured after the strength of the main parts was checked by the software of ANSYS.Thirdly,according to the designed turbine prototype and experimental requirements,the experimental test platform was designed and manufactured.In view of the fact that most of the experiments were completed in the circulating flume at present.As a result of the limited size of the circulating flume,it was inevitable that there would be marginal effect,which would affect the measurement of the real hydrodynamic performance of the hydraulic turbine.Therefore,the experimental ship with power was designed and manufactured.The layout plan of the experimental platform is proposed,the overall stress model of the experimental platform during the experimental test was established.The buoyancy of the experimental platform was calculated,and the appropriate propeller was selected to ensure that the experimental platform ship not only could achieve the required test speed,but also was stable and reliable during operation.Finally,based on the above designed hydraulic turbine and experimental test platform,the hydraulic performance of the hydraulic turbine was tested.The hydrodynamic performance parameters such as torque,speed,and energy efficiency were measured during the start-stop process,meanwhile the parameters were also measured under different flow speeds and loads.The experimental results showed that even at a flow velocity of 0.5m/s,the HRITT-DB could still start normally,and the energy efficiency also could reach 45%.The experiment not only proved the rationality of the analysis and calculation using the simulation software XFlow,but also provided experimental support for the subsequent research and engineering promotion of the half-turn turbine. |
