Potential reduction of leakage volume by combining dynamic pressure management and energy recovery in Valencia

Abstract

[EN] The main objective of a drinking water distribution network is to supply all consumption points with the quantity of water demanded under sufficient pressure and quality conditions. Currently, pressure regulation in water supply networks consists of managing pressure of district metered areas (DMAs) to ensure a sufficient supply to users, being traditionally carried out by reducing excessive pressures, and therefore diminishing water losses. The most basic form of regulation is to maintain a constant pressure at the inlet of the DMAs by means of a pressure reducing valve (PRV). Another turn on the screw in regulation is dynamic sectorization, modifying the set points of the PRVs according to the time of the day to reduce pressure during off-peak hours. This modification of the set point in the PRV involves the movement of a mechanism, requiring a constant energy source. This work proposes the incorporation of an energy recovery system in the distribution network by installing small water turbines at the inlet of the DMA in order to obtain the necessary energy to feed the dynamic regulation equipment, coming the energy required from the network itself. In a complementary way it is also proposed to install a solar photovoltaic system at the inlet of the DMAs. The case study proposed is the water distribution system of the city of Valencia, where four DMAs will be selected for the analysis of the dynamic sectorization. To do that, in the first place it is required to analyse the potential energy recovery in the inlets of the DMAs taking into count average values of pressure upstream and downstream and the minimum night flow. This parameter is one of the criteria selections for the pilot DMAs. For each DMA, a hydraulic model will be calibrated for the subsequent analysis of the pressure regulation enabling to evaluate the alternatives of dynamic pressure management: by time control, flow control and critical point control. The results from these four pilot DMAs will be extrapolated to the rest of the DMAs of the city of Valencia, quantifying economically both water savings and the cost of installation of the small water turbines, with the purpose of bringing the city closer to an example of climate-neutral supply.