water distribution system Articles
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Robustness-based optimal pump design and scheduling for water distribution systems
We introduce a new system robustness index for optimizing the pump design and operation of water distribution systems. Here, robustness is defined as a system's ability to continue functioning under varying demand conditions. The maximum difference between the daily maximum and minimum pressures of a node was taken as a robustness indicator and incorporated as a constraint in a pump design ...
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Automated parameter optimization of a water distribution system
The hydraulic model EPANET was applied and calibrated for the water distribution system (WDS) of La Sirena, Colombia. The Parameter ESTimator (PEST) was used for parameter optimization and sensitivity analysis. Observation data included levels at water storage tanks and pressures at monitoring nodes. Adjustable parameters were grouped into different classes according to two different scenarios ...
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Water distribution system model calibration under uncertainty environments
The calibration process of water distribution system models allows for accurate and reliable hydraulic analysis results. Thus, calibration is of utmost importance if adequate operation and maintenance model-based procedures are sought. However, in emerging economies, there is a series of factors that make it more difficult to construct accurate models, including very poor information management, ...
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Application of genetic programming to modeling pipe failures in water distribution systems
The water loss from a water distribution system is a serious problem for many cities, which incurs enormous economic and social loss. However, the economic and human resource costs to exactly locate the leakage are extraordinarily high. Thus, reliable and robust pipe failure models are demanded to assess a pipe's propensity to fail. Beijing City was selected as the case study area and the pipe ...
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Merged two-level optimization for optimal pump operation of large scale urban water distribution system
Subsequent to the least cost design problem of water distribution systems (WDSs), optimal operation is probably the most explored topic. Since 1970 a variety of methods have been developed to address this problem. Although the proposed methods give theoretic ways for solving optimal operation problems of WDSs, there are little successful application cases in practice, especially when the ...
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Study on the impacts of peaking factors on a water distribution system in Germany
This paper aims to explore the impacts of peaking factors on a water distribution system designed for a small city in Germany through model-based analysis. As a case study, the water distribution network was modelled by EPANET and then two specific studies were carried out. The first study tested corresponding system-wide influences on water age and energy consumption if the peaking factors used ...
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Influence of cavitation phenomenon on the hydraulic behavior of leaks in water distribution systems
This paper examines the hydraulic behavior of leakage from water distribution systems under condition of cavitation. For this purpose, an experimental model featuring small (i.e., a fraction of a millimeter) orifice openings was designed and built to simulate idealized cracks in defective pipes. During the tests, water was allowed to flow through the cracks at controlled pressures during ...
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An agent-based modeling framework for sociotechnical simulation of water distribution contamination events
In the event that a contaminant is introduced to a water distribution network, a large population of consumers may risk exposure. Selecting mitigation actions to protect public health may be difficult, as contamination is a poorly predictable dynamic event. Consumers who become aware of an event may select protective actions to change their water demands from typical demand patterns, and new ...
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Equivalent hydraulic resistance to simulate pipes subject to diffuse outflows
In water distribution network simulation models, pipes subject to diffuse outflow, either due to connections or to distributed demand or to leaks along their length, are generally converted into pipe elements only subject to lumped demand at their ending nodes. This approximation, which disregards the flow variation along the pipes, generates a loss of axial momentum, which is not correctly taken ...
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Characterising the pressure-leakage response of pipe networks using the FAVAD equation
This study investigated the feasibility of characterising the pressure-leakage response of water distribution systems using the FAVAD (Fixed and Variable Area Discharges) equation, instead of the conventional N1 power equation. The study was based on 300 network models with randomly distributed leaks and 35 networks generated through a sensitivity analysis. It was found that the leakage rate ...
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Pipe burst diagnostics using evidence theory
This paper presents a decision support methodology aimed at assisting Water Distribution System (WDS) operators in the timely location of pipe bursts. This will enable them to react more systematically and promptly. The information gathered from various data sources to help locate where a pipe burst might have occurred is frequently conflicting and imperfect. The methodology developed in this ...
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Chlorate formation in water distribution systems: a modeling study
Chlorine-based disinfection agents are known to favor the production of disinfection by-products (DBPs), whose concentrations are restricted by international guidelines to ensure a safe consumption of drinking water. Hence, it is important to understand the behavior of DBPs within water distribution networks (WDNs) to avoid users' exposure to concentrations higher than guideline values. The ...
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Pipe roughness calibration in water distribution systems using grey numbers
This paper presents a procedure based on the use of grey numbers for the calibration (with uncertainty) of pipe roughness in water distribution systems. The pipe roughness uncertainty is represented through the grey number amplitude (or interval). The procedure is of a wholly general nature and can be applied for the calibration (with uncertainty) of other parameters or quantities, such as nodal ...
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A general framework of chlorine decay modeling at a pilot-scale water distribution system
Understanding the variation of chlorine concentrations in water distribution systems is important for determining the schedule of rechlorination. Maintaining an appropriate chlorine concentration in domestic tap water and a sustainable residual chlorine in water distribution systems is an important commitment to ensure high drinking water quality. A generic modeling framework is proposed to ...
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Data reconstruction of flow time series in water distribution systems – a new method that accommodates multiple seasonality
The purpose of this paper is to present a simple yet highly effective method to reconstruct missing data in flow time series. The presence of missing values in network flow data severely restricts their use for an adequate management of billing systems and for network operation. Despite significant technology improvements, missing values are frequent due to metering, data acquisition and ...
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Simultaneous corrosion control and water quality improvement in water distribution systems
The effects of different dosages of sodium hexametaphosphate and sodium orthophosphate on corrosion inhibition and water quality in two model water distribution systems, and the corrosion inhibition mechanism on pipe walls were investigated. Results show that adding sodium hexametaphosphate and sodium orthophosphate can not only provide a remedy for the damaged cement coating surface, but ...
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Stochastic simulation methodology for resilience assessment of water distribution networks
Water distribution systems enable social and economic development and sustain people quality of life. However, these systems face significant performance challenges including ageing, natural disruptive events, and man–made disruptions. Physical protection of networked infrastructure distributed over large geographical areas is unfeasible. A cost–effective alternative is to enhance the water ...
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Multi-objective optimization for conjunctive placement of hydraulic and water quality sensors in water distribution systems
Near real-time continuous monitoring systems have been proposed as a promising approach for enhancing drinking water utilities detect and respond efficiently to threats on water distribution systems. Water quality sensors are aimed at revealing contamination intrusions, while hydraulic pressure and flow sensors are utilized for estimating the hydraulic system state. To date optimization models ...
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Sensitivity of algorithm parameters and objective function scaling in multi-objective optimisation of water distribution systems
This paper presents an extensive analysis of the sensitivity of multi-objective algorithm parameters and objective function scaling tested on a large number of parameter setting combinations for a water distribution system optimisation problem. The optimisation model comprises two operational objectives minimised concurrently, the pump energy costs and deviations of constituent concentrations ...
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Bayesian modelling for water loss management decisions
Bayesian networks and their associated methods are especially suited for capturing and dealing with uncertainty. They can be successfully applied both in engineering sciences and in reliability analyses of water distribution systems. In this paper we propose an interactive Bayesian network and a decision-theoretic system which intend to monitor water loss, predict likely outcome and select ...
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