A deep-water in-situ power generation system based on chain-driven hydrokinetic turbine

Harnessing hydrokinetic energy from deep water to increase the operation periods of autonomous underwater vehicles and underwater moored platforms has received considerable attention in recent years. Hydrokinetic turbines should have a reliable startup performance for deployment in deep water with a prevailing average current speed of 0.5 m/s. In the present study, a deep-water in-situ power generation system based on a novel chain-driven hydrokinetic turbine is proposed for such low-speed current application. A numerical simulation was performed on the proposed turbine to investigate its hydrodynamic performance at different initial setting positions and tip speed ratios. No static dead band exists in the operation of the turbine, indicating a superior self-starting advantage over traditional drag-type turbines. Multi-objective optimization was performed on the proposed turbine to improve its power coefficient and startup performance. Compared with the initial design (C_p = 0.234, C_t,s = 0.520), the C_p and C_t,s in the Pareto front range from 0.103 to 0.325 and 0.565 to 0.712, respectively. All-process simulation was conducted based on Simulink to estimate the power supply capacity of a deep-water in-situ power generation system using the optimal chain-driven hydrokinetic turbine. The result shows that this system can generate the electricity at 218.45 Wh/day in the deep-water location with an average current speed of 0.334 m/s, providing enough energy to the power units of autonomous underwater vehicles.