A mathematical model to evaluate apparent losses due to meter under-registration in intermittent water distribution networks

2013 ◽  
Vol 13 (4) ◽  
pp. 914-923 ◽  
Author(s):  
M. De Marchis ◽  
C. M. Fontanazza ◽  
G. Freni ◽  
G. La Loggia ◽  
V. Notaro ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Water Distribution ◽  
Distribution Networks ◽  
Mediterranean Area ◽  
Water Shortage ◽  
Gradient Algorithm ◽  
Water Volume ◽  
Demand Model ◽  
Hydraulic Network ◽  
Water Meter

Apparent losses consist of water volume drawn from the network, consumed by users but not paid for. Those due to water meter under-registration were evaluated by means of a mathematical model able to analyse the complexity of intermittent supply systems with private tanks. This supply scheme is very common in the Mediterranean area where unexpected water shortage often happens and intermittent water supply is a common practice. In order to analyse such complex systems, a demand model, reproducing the effect of private tanks, and an apparent losses module were developed and coupled with an hydraulic network model based on the Global Gradient Algorithm (GGA). In distribution networks pressure reduction valves (PRVs) are often used by water utilities to control the pressure and reduce background losses. These practices could influence the performance of water meters. For this reason, a PRV model was implemented and integrated with the demand and the hydraulic network models to better estimate the effect of pressure management on real and apparent losses. The comprehensive model was applied to a real case study. The proposed modelling approach was used to identify regions of the network with high apparent losses. Furthermore, the model may be used to predict the results of a water meter replacement plan and of the installation of devices that could affect apparent losses.

scholarly journals A Framework for Identifying the Critical Region in Water Distribution Network for Reinforcement Strategy from Preparation Resilience

2020 ◽  
Vol 12 (21) ◽  
pp. 9247
Author(s):  
Mingyuan Zhang ◽  
Juan Zhang ◽  
Gang Li ◽  
Yuan Zhao
Keyword(s):  
Water Distribution ◽  
Large Scale ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Distribution Networks ◽  
Water Shortage ◽  
Hydraulic Control ◽  
Urban Function ◽  
Network Disruption ◽  
Critical Regions

Water distribution networks (WDNs), an interconnected collection of hydraulic control elements, are susceptible to a small disturbance that may induce unbalancing flows within a WDN and trigger large-scale losses and secondary failures. Identifying critical regions in a water distribution network (WDN) to formulate a scientific reinforcement strategy is significant for improving the resilience when network disruption occurs. This paper proposes a framework that identifies critical regions within WDNs, based on the three metrics that integrate the characteristics of WDNs with an external service function; the criticality of urban function zones, nodal supply water level and water shortage. Then, the identified critical regions are reinforced to minimize service loss due to disruptions. The framework was applied for a WDN in Dalian, China, as a case study. The results showed the framework efficiently identified critical regions required for effective WDN reinforcements. In addition, this study shows that the attributes of urban function zones play an important role in the distribution of water shortage and service loss of each region.

scholarly journals Mathematical model as a standard procedure to analyze small and large water distribution networks

2015 ◽  
Vol 106 ◽  
pp. 541-554 ◽  
Author(s):  
M.A. Prieto ◽  
M.A. Murado ◽  
J. Bartlett ◽  
W.L. Magette ◽  
Thomas P. Curran
Keyword(s):  
Mathematical Model ◽  
Water Distribution ◽  
Standard Procedure ◽  
Distribution Networks ◽  
Water Distribution Networks ◽  
Large Water

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 Comparative analysis of air scouring and unidirectional flushing of water distribution systems

2020 ◽  
Vol 69 (6) ◽  
pp. 578-590
Author(s):  
Florent Pourcel ◽  
Sophie Duchesne
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Total Suspended Solid ◽  
Distribution Networks ◽  
Water Distribution Networks ◽  
Water Volume ◽  
Particle Removal ◽  
Suspended Solid Concentration ◽  
Low Efficiency

Abstract Unidirectional flushing is a widely used method to remove sedimented particles from water distribution systems and prevent water discolouration events. However, it shows low efficiency in cases of high pressure losses, usually requires large volumes of water, and does not remove incrustations. Air scouring is known for being very effective in particle removal with minimal impacts from pressure loss, requiring little water and improving hydraulic capacities by removing soft incrustations. Flushing sequences of unidirectional flushing and air scouring were performed in similar conditions on 18 pipe sections from four water distribution networks located in the province of Quebec, Canada; unidirectional flushing was also performed on 14 additional pipe sections located in three other water distribution networks. Total suspended solid concentration of flushed water, water flow and pressure were recorded to estimate the amount of flushed particles, the required water volume and the evolution of hydraulic capacities. Within the studied networks, the water requirements for air scouring were approximately 8-fold less than for unidirectional flushing and did not significantly improve the hydraulic capacity of the cleaned pipes.

Optimal Operation of Water Distribution Networks under Water Shortage Considering Water Quality

2016 ◽  
Vol 7 (3) ◽  
pp. 04016005 ◽  
Author(s):  
Mohammad Solgi ◽  
Omid Bozorg-Haddad ◽  
Samaneh Seifollahi-Aghmiuni ◽  
Parisa Ghasemi-Abiazani ◽  
Hugo A. Loáiciga
Keyword(s):  
Water Quality ◽  
Water Distribution ◽  
Distribution Networks ◽  
Water Shortage ◽  
Optimal Operation ◽  
Water Distribution Networks

Optimization of small hydropower systems in water distribution networks through evolutionary algorithms and water demand forecasting

2021 ◽  
Author(s):  
Robert Sitzenfrei ◽  
Lukas Schartner ◽  
Martin Oberascher
Keyword(s):  
Drinking Water ◽  
Water Demand ◽  
Water Distribution ◽  
Distribution Networks ◽  
Water Distribution Networks ◽  
Water Volume ◽  
Hydropower Production ◽  
Water Surplus ◽  
Demand Forecasts

<p>The transition from fossil fuel to renewable energies represents the central challenge of the early 21st century. In this context, small hydro power systems (SHPS) can be implemented in water distribution networks (WDNs) to use pressure and drinking water surplus for hydropower production. However, inflow to SHPS is normally controlled based on the available water volume after ensuring a reliable drinking water supply and considering a fire-fighting reserve. Hence, the hydropower generation in WDNs has to be in accordance with its primary tasks. The challenge now is to optimally use the available pressure and water surplus for hydropower production while at the same time reliably fulfilling drinking water constraints.</p><p>In this work, future predictions of daily water demand are added into the control strategy of SHPS to optimize the operation. The control procedure of a SHPS is optimized by means of an evolutionary algorithm in combination with Monte-Carlo sampling. This is done for different categorized water demand and water source data in order to maximize profit while ensuring the WDNs reliable operation. Further, water demand forecasts of varying quality are evaluated in combination with previously optimized and categorized SHPS control-sets. For case study, a real WDN of an Alpine municipality is hypothetically retrofitted with a controllable SHPS. Different types of SHPS and turbine characterises are investigated using amount of hydropower production, more specifically profitability, as performance indicator.</p><p>While in literature, optimization is usually performed based on representative days (e.g., average day demand), long-term simulations over 10 years are used in this work. Therefore, a sufficient supply pressure in all water demand nodes in the WDN is ensured during this period. This results in a significant lower but more realistic estimation of potential benefits. The results also show, that after optimizing the SHPS location and device size, an additional potential increase of yearly profit of 1.1% can be achieved in the long-term operation of a Pelton turbine by considering water demand forecasts.</p>

Performance Analysis of Ageing Domestic Water Meters with Respect to Apparent Losses: A Case Study

2019 ◽  
Vol 3 (1) ◽  
pp. 69-80
Author(s):  
Christian Camilleri ◽  
Luke Pace ◽  
Alex Rizzo
Keyword(s):  
Measurement Errors ◽  
Water Distribution ◽  
Planning Process ◽  
Distribution Networks ◽  
Testing Procedure ◽  
Low Flow ◽  
Domestic Water ◽  
Flow Rates ◽  
One Year ◽  
Water Meter

In water distribution networks, a substantial amount of Apparent Losses result from water-meter errors. This study aims to evaluate water-meter under-registration, specifically the effect of ageing on the meter measurement errors, controlled at different flow-rates. The study was initiated by establishing a holistic methodology highlighting the planning process and meter-testing procedure. The results achieved show that the metrological percentage meter error is highly pronounced at low flow-rates. In the case of medium to high flow-rates for one-year, three-year, and five-year-old class of meters, meter errors were not statistically significant. However, an opposite outcome for the same flow-rates resulted for the seven-year class meter.

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