Design Of The Flow Guide Sleeve Of The Tidal Current Energy Turbine Base On The Offshore Cage System

Currently, domestic research on environment-friendly offshore cage lags behind other countries since the automatic control system is difficult to solve the problem of power supply. Therefore, it is essential to design a tidal current energy capture device which is strong in generating capacity and high in generating efficiency and it is required that the device should work normally at low flowing velocity in order to meet the offshore cage's demand for power supply. The paper mainly includes the following contents:Firstly, this paper analyzes the power consumption of offshore cage system and establishes a half-month mathematical model for the generating capacity of tidal current turbine according to the hydrological condition of the waters where the offshore cage is placed. Meanwhile, this paper analyzes and compares the structural forms of tidal current energy capture impeller and adopts the horizontal-spindle impeller with flow guide sleeve as the tidal current power capture impeller for offshore cages.Secondly, according to CFD simulation computation principles, this paper probes into the nature of the fluid in the flow field where the offshore cage is placed and establishes a 3D hydrodynamics analysis mode for tidal current turbine. In combination with BEM theory, it builds the mathematical model for predicting the power capture coefficient and axial force coefficient of the water turbine, and makes a preliminary summary of the turbine's hydrodynamic performance.Thirdly, the flow guide sleeve structure of the turbine impeller is optimized according to the power demand of the offshore cages; the paper investigates the hydrodynamic characteristics of the whole tidal power generation device and finds out the influence of different flow guide sleeve parameters on the performance of tidal current turbine. Appropriate flow guide sleeves are selected for the turbine on the premise of satisfying the power demand of offshore cages.Finally, the paper carries out a fluid-solid coupling analysis over the impeller with flow guide sleeve under different work conditions and obtains the corresponding curves on capture power, axial thrust, power capture coefficient and thrust coefficient, etc; in the meantime, the paper delves into the structural performance of the impeller and obtains the stress-strain curve of the impeller structure, which provides the basis for the use of the whole tidal current energy capture device in offshore cage system.