A novel pressure regulation system based on Banki hydro turbine for energy recovery under in-range and out-range discharge conditions

Efficiency improvement of water distribution networks needs to be in place to guarantee a long life period under suitable operating conditions. Excessive pressure is among the well-known issues encountered in water distri- bution networks which can cause strength damages to the piping system. In order to overcome this drawback and to reach a suitable water pressure delivery, the present work suggests a novel pressure regulation system. This regulation system is consisting of a Banki turbine equipped with a mobile flap as a control device. The suggested pressure regulation system was experimentally and numerically investigated under in-range i.e. like actual water distribution networks and out-range flow conditions. A set of computational fluid dynamic simulations was carried out to study the performance and flow characteristics around the turbine with and without a mobile flap. The flow solution was obtained by solving the Reynolds-averaged Navier–Stokes equations. Different rotor–stator interface and turbulence models, and mesh sizes were investigated to select the most accurate configuration of the numerical method. The validation of the numerical method was performed with an assessment of the standard error with respect to experimental data. Based on the experimental results, three correlations estimating the net head, the torque and the efficiency for given flap angle and volumetric flow rate were presented. Results revealed that the suggested regulation system presents a good efficiency up to 76% to recover the wasted hy- drodynamics energy in water distribution networks.