Development of a technique to optimize micro-hydro turbine location and capacity for optimal pressure control and energy recovery in water systems

In the water supply system, for stable operation and management, pressure control, and energy consumption are important factors. However, gravity flow water supply systems can cause leaks and pipe damage when high pressure from upstream moves downstream. Therefore, the only popular way to control pressure within an acceptable range is to use a pressure reduction valve to control pressure within an appropriate range. However, using only the pressure reduction valve causes indiscriminate energy waste in operating and managing the water supply system. Accordingly, a micro-hydro turbine was proposed to replace the pressure reduction valve to provide appropriate pressure control and energy recovery. In addition, existing micro-hydro turbine designs were designed with only energy recovery in mind, but for sustainable operation, various design factors must be considered for optimal design. However, in design, EPANET2.2, the model simulation program in this study, does not have a model that can calculate the size of the turbine, so it is replaced with the pressure reduction valve and designed using the corresponding pressure and flow rate. Therefore, in this study, the range that satisfies the appropriate pressure condition is determined by using the pressure reduction valve (if a micro-hydro turbine is used with a surplus pressure head considering appropriate pressure control, the potential energy recovery amount can be determined). Therefore, a multi-objective optimal design technique was proposed that can optimize objective functions such as energy recovery and installation cost. The optimization technique is a multi-objective harmony search, and benchmark networks were applied to verify the proposed methodology. Through this study, it is expected that it can be effectively used in the sustainable operation of the water supply system by considering various design factors through adjustment of the set pressure.