The paper describes the actions performed to reduce leakages in the water distribution system in Mantova (Italy) and the results achieved. This project involved the integration of a mathematical model with specialist software in order to design pressure management zones (PMZs) and districts (DMAs), to optimise pressure management and to manage leakage. The mathematical model presents some unique features, particularly the simulation of the spatial-time variations of BAC (Billed Authorized Consumption) and NRW (Non Revenue Water) applied in presence of DMAs properly defined. In order to calculate the Pressure Adjusted NRW Volume, the average value of the N1 pressure-leakage relationship exponent during the period of the Baseline Survey was established by means of N1 tests involving stepping down pressures into the zone during the period of minimum flow and recording the change in average zone pressure and the change in zone inflow. The advanced pressure control system operates in real time both pumps and PRVs to minimise pressure in the system and to monitor leakage level and the occurrence of pressure transients. In fact in TEA system some pressure sensors (connected to the real time pressure control system) are also able to catch the water hammer by monitoring pressure with sampling frequency lower than 1/10 sec, when the pressure exceeds a predefined maximum value. In some zones, fed by direct pumping, the pump is fitted with a variable frequency drive (VFD) and a controller in order to vary the outlet of the pump and maintain a stable and optimal pressure at the critical point(s). Similarly in other zones, fed by pressure reducing valves (PRV), an optimal pressure level is achieved by modulating pressure at the PRV directly from the controller in order to keep the pressure at the minimum level at the critical point. The methodology itself demonstrates its validity regarding the assessment of reduced losses and bursts frequency as well as reduced energy consumption in the overall network.
Advanced leakage and pressure control in TeaAcque water utility in Mantova (Italy) by means of integrated mathematical models, leakage specialist software and real time pressure control system
FRANCHINI, Marco;ANSALONI, Nicola;ALVISI, Stefano;
2014
Abstract
The paper describes the actions performed to reduce leakages in the water distribution system in Mantova (Italy) and the results achieved. This project involved the integration of a mathematical model with specialist software in order to design pressure management zones (PMZs) and districts (DMAs), to optimise pressure management and to manage leakage. The mathematical model presents some unique features, particularly the simulation of the spatial-time variations of BAC (Billed Authorized Consumption) and NRW (Non Revenue Water) applied in presence of DMAs properly defined. In order to calculate the Pressure Adjusted NRW Volume, the average value of the N1 pressure-leakage relationship exponent during the period of the Baseline Survey was established by means of N1 tests involving stepping down pressures into the zone during the period of minimum flow and recording the change in average zone pressure and the change in zone inflow. The advanced pressure control system operates in real time both pumps and PRVs to minimise pressure in the system and to monitor leakage level and the occurrence of pressure transients. In fact in TEA system some pressure sensors (connected to the real time pressure control system) are also able to catch the water hammer by monitoring pressure with sampling frequency lower than 1/10 sec, when the pressure exceeds a predefined maximum value. In some zones, fed by direct pumping, the pump is fitted with a variable frequency drive (VFD) and a controller in order to vary the outlet of the pump and maintain a stable and optimal pressure at the critical point(s). Similarly in other zones, fed by pressure reducing valves (PRV), an optimal pressure level is achieved by modulating pressure at the PRV directly from the controller in order to keep the pressure at the minimum level at the critical point. The methodology itself demonstrates its validity regarding the assessment of reduced losses and bursts frequency as well as reduced energy consumption in the overall network.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
