Optimization and System Identification of a Variable Pico-Scale Hydro Turbine for Pressure Regulation

Recent studies from the European Commission estimate that more than 20% of global energy is consumed by pumping systems. Significant research has focused on increasing pump efficiency to lower energy consumption; however, few have looked at the energy lost in use of pressure regulating devices (PRDs). This paper proposes a novel pico-scale hydro turbine that could effectively replace PRDs and generate power while regulating pressure. The proposed hydro turbine has an outer diameter of 4″ and a total length of 5.4″. The turbine uses 14 rotating guide vanes and is attached to a generator with a variable load. To maximize power recovery and pressure control range of the turbine, a non-dominated sorting genetic algorithm was used for multi-objective geometry optimization. Then, to build a dynamic model for control system design, parameter identification was conducted using a Gaussian process surrogate model and stochastic search algorithms: particle swarm optimization and genetic algorithm. The optimized turbine showed good agreement between simulated and experimental results and achieved a power output of 120 W, pressure drop range of 6 to 27 psi, and maximum hydraulic efficiency of 75% at the rated flow rate of 27 GPM. The optimized turbine shows the potential of pico-turbines for pressure regulation.