During the past few years, issues concerning sustainable management of water distribution systems have attracted interest through an integrated policy aimed at reducing leakage through a pressure management strategy. Pressure reducing valves (PRVs) are often used in water networks to prevent the downstream hydraulic grade from exceeding a set value, although they must be adequately located to maximize their effectiveness. In recent years, the application of turbines or pumps operating as turbines (PATs) appeared as an alternative and sustainable solution to control network pressure and produce energy. In the present paper, PRVs and PATs were used within a district in a Naples’ water distribution network and showed large potential revenues and an attractive capital payback period.

Pressure reducing valves (PRVs) are often used to manage pressure and reduce losses in water distribution systems (WDS). Different approaches are available in the literature on how to locate and set the PRVs in order to maximize their effectiveness and minimize water losses. The available methodologies minimize the mean square difference between the actual and the target pressure at each node. Since the excess head can be used also to generate hydropower by using turbines and/or pumps as turbines (PATs), a different objective function could be suggested to maximize energy production. Consequently, a comprehensive analysis will be developed in the paper which highlights the differences between the preexisting approach and the suggested one, in terms of device location, pressure reduction, and recoverable energy. Numerical simulations showed that minimizing pressure may also affect the production of energy, while maximizing the energy production itself could be an attractive alternative, leading to ...

Studies have shown that real-time control (RTC) of pressure in water distribution networks (WDNs) can be very effective for leakage reduction. The aim of RTC is to regulate the pressure level over the WDN by guaranteeing a pressure that is nearly constant and as low as possible at the critical node. To this end, a pressure reducing valve (PRV) at the network inlet can be remotely controlled to ensure the optimal service level, regardless of upstream pressure and inflow. Field experiments in a district of Benevento, Italy are carried out to assess the suitability of the proposed approach. Results show that the system guarantees the required pressure at the critical node at all times. The controller is effective in optimizing pressure levels over the entire WDN by also reducing excessive pressure in the other nodes. Experiments show that the pressure control is effective in reducing leakage, as confirmed by the minimum night flow (MNF) measurements.

In this paper, considering time-averaged velocity as a random variable, two-dimensional (2D) velocity distributions in open-channel flow have been derived based on the Shannon entropy concept and the principle of maximum entropy. The velocity distributions so derived have limited practical use, since they contain too many parameters that need to be experimentally calibrated and hence are not convenient to apply. This work develops a new entropy-based approach for deriving a 2D velocity distribution in open-channel flow, thereby investigating a rectangular geometric domain. The derived distribution is parsimonious, and the values determined using the proposed distribution are found to be in good agreement with the experimentally-measured velocity values.