scholarly journals Multivariate statistical analysis for water demand modelling: implementation, performance analysis, and comparison with the PRP model

2015 ◽  
Vol 18 (1) ◽  
pp. 4-22 ◽  
Author(s):  
Chiara M. Fontanazza ◽  
Vincenza Notaro ◽  
Valeria Puleo ◽  
Gabriele Freni
Keyword(s):  
Statistical Analysis ◽  
Return Period ◽  
Water Demand ◽  
Distribution Systems ◽  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Water Volume ◽  
Demand Model ◽  
Consumption Data

Water demand is the driving force behind hydraulic dynamics in water distribution systems. Consequently, it is crucial to accurately estimate the actual water use to develop reliable simulation models. In this study, copula-based multivariate analysis was proposed and used for demand prediction for a given return period. The analysis was applied to water consumption data collected in the water distribution network of Palermo (Italy). The approach produced consistent demand patterns and could be a powerful tool when coupled with water distribution network models for design or analysis problems. The results were compared with those obtained using a classical water demand model, the Poisson rectangular pulse (PRP) model. The multivariate consumption data statistical analysis results were always higher than those of the PRP model but the copula-based method maintained the daily water volume of actual consumptions and provided maximum daily consumption that increased with the return period.

scholarly journals Assessing the Impact of DMAs and the Use of Boosters on Chlorination in a Water Distribution Network in Greece

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2141
Author(s):  
Stavroula Tsitsifli ◽  
Vasilis Kanakoudis
Keyword(s):  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Assessment Process ◽  
Water Volume ◽  
Pressure Management ◽  
Water Age ◽  
Chlorination Process ◽  
Management Measures ◽  
The Impact

Disinfection is one of the most important water treatment processes as it inactivates pathogens providing safe drinking water to the consumers. A fresh-water distribution network is a complex system where constant monitoring of several parameters and related managerial decisions take place in order for the network to operate in the most efficient way. However, there are cases where some of the decisions made to improve the network’s performance level, such as reduction of water losses, may have negative impacts on other significant operational processes such as the disinfection. In particular, the division of a water distribution network into district metered areas (DMAs) and the application of various pressure management measures may impact the effectiveness of the water chlorination process. Two operational measures are assessed in this paper: (a) the use of inline chlorination boosters to achieve more efficient chlorination; and (b) how the DMAs formation impacts the chlorination process. To achieve this, the water distribution network of a Greek town is chosen as a case study where several scenarios are being thoroughly analyzed. The assessment process utilizes the network’s hydraulic simulation model, which is set up in Watergems V8i software, forming the baseline to develop the network’s water quality model. The results proved that inline chlorination boosters ensure a more efficient disinfection, especially at the most remote parts/nodes of the network, compared to conventional chlorination processes (e.g., at the water tanks), achieving 100% safe water volume and consuming almost 50% less chlorine mass. DMAs’ formation results in increased water age values up to 8.27%, especially at the remote parts/nodes of the network and require more time to achieve the necessary minimum effective chlorine concentration of 0.2 mg/L. However, DMAs formation and pressure management measures do not threaten the chlorination’s efficiency. It is important to include water age and residual chlorine as criteria when optimizing water pressure and the division of DMAs.

scholarly journals Optimal placement of valves in a water distribution network with CLP(FD)

2011 ◽  
Vol 11 (4-5) ◽  
pp. 731-747 ◽  
Author(s):  
MASSIMILIANO CATTAFI ◽  
MARCO GAVANELLI ◽  
MADDALENA NONATO ◽  
STEFANO ALVISI ◽  
MARCO FRANCHINI
Keyword(s):  
Logic Programming ◽  
Distribution Systems ◽  
Water Distribution ◽  
Distribution Network ◽  
Real Life ◽  
Water Distribution Network ◽  
Distribution Networks ◽  
Constraint Logic Programming ◽  
Optimal Placement ◽  
Isolation System

AbstractThis paper presents a new application of logic programming to a real-life problem in hydraulic engineering. The work is developed as a collaboration of computer scientists and hydraulic engineers, and applies Constraint Logic Programming to solve a hard combinatorial problem. This application deals with one aspect of the design of a water distribution network, i.e., the valve isolation system design. We take the formulation of the problem by Giustolisi and Savić (2008 Optimal design of isolation valve system for water distribution networks. InProceedings of the 10th Annual Water Distribution Systems Analysis Conference WDSA2008, J. Van Zyl, A. Ilemobade, and H. Jacobs, Eds.) and show how, thanks to constraint propagation, we can get better solutions than the best solution known in the literature for the Apulian distribution network. We believe that the area of the so-calledhydroinformaticscan benefit from the techniques developed in Constraint Logic Programming and possibly from other areas of logic programming, such as Answer Set Programming.

scholarly journals Application of Routine Calibration of Real Water Supply Network with Adjustment of Demand Roughness Parameters Driven by Applied Pressure Real Network of Brazil

10.29007/z3hq ◽  
2018 ◽  
Author(s):  
Fernando Das Graças Braga Da Silva ◽  
Thaisa Dias Goulart ◽  
Regina Mambeli Barros
Keyword(s):  
Water Distribution ◽  
Distribution Network ◽  
Applied Pressure ◽  
Water Distribution Network ◽  
Distribution Networks ◽  
Calibration Method ◽  
Decision Variable ◽  
Demand Model ◽  
Real Network ◽  
Search Tool

The calibration of water distribution networks is one way to perform such procedures in hydraulic models, but several are the difficulties encountered in calibrating a real network. This work proposes the improvement of modules of the calibration method proposed by Silva (2003), where using the genetic algorithm (GA) search tool, the author calibrates a real water distribution network of a Brazilian city, adjusting parameters mainly from roughness and coefficient of leakage. The enhancement of GA is the introduction of a new decision variable, the nodal demand, which assigns demand values to nodes according to the pressure-driven demand model of Tucciarelli, Criminisi and Termini (1999). The tests of the GAs implemented are tested for this real water distribution network presented by Silva (2003). The effect of the improvement on the calibration results was significant for the network, but the need for more in-depth studies, which are of course required for the application of new algorithms in real-scale networks.

scholarly journals Online simplification of water distribution network models for optimal scheduling

2013 ◽  
Vol 15 (3) ◽  
pp. 652-665 ◽  
Author(s):  
Daniel Paluszczyszyn ◽  
Piotr Skworcow ◽  
Bogumil Ulanicki
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Distribution Network ◽  
Network Models ◽  
Water Distribution Network ◽  
Simplified Model ◽  
Reduced Model ◽  
Water Network ◽  
Pump Speed ◽  
Online Optimisation

This paper presents an implementation of an extended simplification algorithm of water distribution network models for the purpose of inclusion in the online optimisation strategy for energy and leakage management in water distribution systems. Whereas the previously proposed reduced model represented accurately the original hydraulic water network characteristics, the energy distribution in the simplified model was not preserved. This could cause a situation where the pump speed required to satisfy specified minimum pressure constraints is different for the reduced model and the original model. This problem has been identified, and an appropriate modification to the simplification algorithm has been introduced. The idea comprises introduction of the energy audit of the water network and the calculation of new minimum service pressure constraints for the simplified model. The approach allows the preservation of both hydraulic and energetic characteristics of the original water network and therefore meets the requirements of the online optimisation strategy. Suitability of the proposed approach is evaluated via a case study. The modern parallel programming implementation allowed water network models consisting of several thousand elements to be reduced within 2 min with an average relative accuracy of less than 2% in terms of tanks flows.

scholarly journals Risk-based sensor placement methods for burst/leak detection in water distribution systems

2017 ◽  
Vol 17 (6) ◽  
pp. 1663-1672 ◽  
Author(s):  
E. Forconi ◽  
Z. Kapelan ◽  
M. Ferrante ◽  
H. Mahmoud ◽  
C. Capponi
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Social Economic ◽  
Water Distribution Systems ◽  
Water System ◽  
Water Distribution Network ◽  
Leak Detection ◽  
Optimal Placement ◽  
Water Volume ◽  
The Impact

Abstract The optimal placement of sensors for burst/leak detection in water distribution systems is usually formulated as an optimisation problem. In this study three different risk-based functions are used to drive optimal location of a given number of sensors in a water distribution network. A simple function based on likelihood of leak non-detection is compared with two other risk-based functions, where impact and exposure are combined with the leak detection likelihood. The impact is considered proportional to the demand water volume while the exposure is related to the importance of the connections and it is evaluated in social, economic or safety terms. The methods are applied to a district metered area of the Harrogate network by means of a modified EPANET model, to take into account the pressure-driven functioning conditions of the system. The results show that the exposure can lead to a different sensor location ranking with respect to other criteria used and hence the proposed methodology can represent a useful tool for water system managers to distribute the sensors in the network, complying with hydraulic, social and economical requirements.

scholarly journals Mathematical model of biofilm-mediated pathogen persistence in a water distribution network with time-constant flows

2018 ◽  
Vol 29 (6) ◽  
pp. 991-1019 ◽  
Author(s):  
SADIQAH AL MARZOOQ ◽  
ALVARO ORTIZ-LUGO ◽  
BENJAMIN L. VAUGHAN
Keyword(s):  
Time Constant ◽  
Distribution Systems ◽  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Large Network ◽  
Time Behaviour ◽  
Long Time Behaviour ◽  
Long Time ◽  
Non Linear System

In industrialized nations, potable water is often provided through sophisticated water distribution systems. If pathogenic bacteria are introduced into the water distribution network, the presence of a biofilm can lead to biofilm-assisted retention of the pathogens, affecting the potability of the water. To study the dynamics of planktonic and biofilm-bound pathogens within the large network of pipes in a water distribution system, we develop a network model governing the concentration of introduced pathogens within the bulk fluid and the biofilms lining the pipes. Under time-constant flow regimes within the network, we prove that the long-time behaviour of the entire network is dependent on the Lyapunov exponents for each connection in the network when viewed in isolation and the network connectivity. An efficient algorithm is developed for predicting the long-time behaviour of the pathogen population within large networks using the network's topological ordering. The algorithm's predictions are validated using numerical simulations of the full non-linear system on a range of water distribution network sizes.

scholarly journals Experimental and numerical effects of flow hydraulics and pipe geometry on leakage behavior of laboratory water network distribution systems

2020 ◽  
Author(s):  
Tamer Nabil ◽  
Fahad Alhaddad ◽  
Mohamed Dawood ◽  
Osama Sharaf
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Distribution Network ◽  
Pressure Sensors ◽  
Water Distribution Network ◽  
Laboratory Model ◽  
Leakage Flow ◽  
Network System ◽  
Flow Rates ◽  
Laboratory Water

Abstract. As the leakage behavior of water distribution network is considered life-threatening and critical issue, so the behavior of water distribution network system is investigated experimentally and numerically under the effect of different positions and flow rates of leakage outlets taking into consideretion the flowhydraulics and pipe geametry. A laboratory model of the real studied water distribution network is constructed. The laboratory water distribution network is horizontal and has 16 loops with total length 30 m and different diameters. The leakage position in the laboratory water distribution network is altered between main, sub-main and branch pipelines with different flow rates. The characteristics of the ideal laboratory water distribution network with no-leakage are studied first. The studied laboratory water distribution network system parameters are solved theoretically using Hardy-Cross method with seven iterations. The studied water distribution network system was simulated using computational fluid dynamics technique Ansys Fluent 18.2. The aim is to modify the ancient water distribution network by sensing the pressure values using dispersed pressure sensors. Also, from the pressure map of the laboratory water distribution network, the leakage position if exist can be localized. Depending on the sensed pressure, the control circuit programmed to close the corresponding solenoid valves. The leakage flow rates are 0.1, 0.25 and 0.4 L/s and changed between the main and sub-main pipes. The maximum pressure drop around 500 pa at the node directly preceding the leakage point at leakage flow rate 0.4 L/s. The performance of the used solenoid valve is simulated using Matlab-Simulink technique. The simulation results show the response to step down control signal is over damped with steady state error 2 % and settling time 0.6 s.

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