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

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.

2014 ◽  
Vol 17 (1) ◽  
pp. 20-35 ◽  
Author(s):  
João Marques ◽  
Maria Cunha ◽  
Dragan A. Savić

This paper presents a real options approach to handling uncertainties associated with the long-term planning of water distribution system development. Furthermore, carbon emissions associated with the installation and operation of water distribution networks are considered. These emissions are computed by taking an embodied energy approach to the different materials used in water networks. A simulated annealing heuristic is used to optimise a flexible eco-friendly design of water distribution systems for an extended life horizon. This time horizon is subdivided into different time intervals in which different possible decision paths can be followed. The proposed approach is applied to a case study and the results are presented according to a decision tree. Lastly, some comparisons and results are used to demonstrate the quality of the results of this approach.


2006 ◽  
Vol 53 (4-5) ◽  
pp. 503-511 ◽  
Author(s):  
D. Misiunas ◽  
J. Vítkovský ◽  
G. Olsson ◽  
M. Lambert ◽  
A. Simpson

An algorithm for the burst detection and location in water distribution networks based on the continuous monitoring of the flow rate at the entry point of the network and the pressure at a number of points within the network is presented. The approach is designed for medium to large bursts with opening times in the order of a few minutes and is suitable for networks of relatively small size, such as district metered areas (DMAs). The burst-induced increase in the inlet flow rate is detected using the modified cumulative sum (CUSUM) change detection test. Based on parameters obtained from the CUSUM test, the burst is simulated at a number of burst candidate locations. The calculated changes in pressure at the pressure monitoring points are then compared to the measured values and the location resulting in the best fit is selected as the burst location. The EPANET steady-state hydraulic solver is utilised to simulate the flows and pressures in the network. A sensitivity-based sampling design procedure is introduced to find the optimal positions for pressure monitoring points. The proposed algorithm is tested on a case study example network and shows potential for burst detection and location in real water distribution systems.


Water ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2321
Author(s):  
Federica Bruno ◽  
Mauro De Marchis ◽  
Barbara Milici ◽  
Domenico Saccone ◽  
Fabrizio Traina

Efficient management of water distribution networks (WDNs) is currently a focal point, especially in countries where water scarcity conditions are more and more amplified by frequent drought periods. In these cases, in fact, pressure becomes the fundamental variable in managing the WDNs. Similarly, WDNs are often obsolete and affected by several points of water losses. Leakages are mainly affected by pressure; in fact, water utilities usually apply the technique of pressure management to reduce physical losses. It is clear how pressure plays a fundamental role in the management of WDNs and in water safety. Even though the technologies are quite mature, these systems are often expensive, especially if a capillarity monitoring system is required; thus, water managers apply the measurement of the flow rate and pressure at very few points. Today, the implementation of the Internet of things (IoT) can be considered a key strategy for monitoring water distribution systems. Once the sensors are installed, in fact, it is relatively easy to build a communication system able to collect and send data from the network. In the proposed study, a smart pressure monitoring system was developed using low-cost hardware and open-source software. The prototype system is composed of an Arduino microcontroller, a printed circuit board, and eight pressure transducers. The efficiency of the proposed tool was compared with a SCADA monitoring system. To investigate on the efficiency of the proposed measurement system, an experimental campaign was carried out at the Environmental Hydraulic Laboratory of the University of Enna (Italy), and hydrostatic as well as hydrodynamic tests were performed. The results showed the ability of the proposed pressure monitor tool to have control of the water pressure in a WDN with a simple, scalable, and economic system. The proposed system can be easily implemented in a real WDN by water utilities, thus improving the knowledge of pressure and increasing the efficiency level of the WDN management.


2021 ◽  
Vol 10 (12) ◽  
pp. e407101220659
Author(s):  
Emerson Pessanha de Almeida ◽  
Fernando das Graças Braga da Silva ◽  
Victor Eduardo de Mello Valerio

The research carried out in the water distribution networks is of great importance, given the social, environmental and economic impacts that have occurred due to the scarcity of water resources. Therefore, any scientific effort shown in research that studies water distribution systems is of great relevance. Techniques such as mathematical modeling, computer simulation and statistical methods are widely used in order to obtain more reliable answers, whether for the identification of the current situation of the network, as well as for the prediction of scenarios, failure events, increased demand, etc. The objective of this work is to carry out a bibliometric analysis to identify the state of the art of research that addresses the theme of water distribution networks for the control and reduction of the volume of water losses, which will serve as a guide for future works to to structure itself in the most relevant researches that study the theme. The developed methodology was able to analyze a metadata composed of 4188 documents taken from the Web of Science journals database. As a result, a geographical view of the theme was obtained, pointing out the main countries, affiliations, journals and researchers, as well as pointing out the main documents and relevance of the theme. It can be concluded after the results obtained that bibliometric analysis is an important tool for obtaining the state of the art. With it is possible to have a better understanding of the current situation in the development of research, familiarizing researchers with what is most current and relevant.


2021 ◽  
Vol 11 (2) ◽  
pp. 143-150
Author(s):  
E. Vitan ◽  
Anca Hotupan ◽  
Adriana Hadarean

Abstract The performance evaluation of an implemented water distribution network is in tight relation with the choice of adequate measures for water loss reduction. Hence, the consequences of placing the water network in a wrong performance category are bad and will conduct to unreasonably costs or considerable water loss volumes. Therefore, the evaluation of the water network performance level based on both Non-Revenue Water (NRW) and Infrastructure Leakage Index (ILI) indicators is to be recommended. This paper deals with the performance evaluation of water distribution systems based on the calculated performance indicators NRW and ILI. For this purpose, collected data for a period of one year from 12 Romanian small water distribution systems and two simplified average pressure determination methods were used.


Author(s):  
Maryam Kammoun ◽  
Amina Kammoun ◽  
Mohamed Abid

Abstract Leakage in water distribution systems is a significant long-standing problem due to the huge economic and ecological losses. Different leak detection studies have been examined in literature using different types of technologies and data. Currently, although machine learning techniques have achieved tremendous progress in outlier detection approaches, they are still limited in terms of water leak detection applications. This research aims to improve the leak detection performances by refining the choices of learning data and techniques. From this perspective, commonly used techniques for leak detection are assessed in this paper, and the characteristics of hydraulic data are investigated. Four intelligent algorithms are compared, namely k-nearest neighbors, support vector machines, logistic regression, and multi-layer perceptron. This study focuses on six experiments based on identifying outliers in various packages of pressure and flow data, yearly data, seasonal data, night data, and flow data difference to detect leakage in water distribution networks. Different scenarios of realistic water demand in two networks from the benchmark dataset LeakDB are used. Results demonstrate that the leak detection accuracy varies between 30% and 100% depending on the experiment and the choices of algorithms and data.


2021 ◽  
Author(s):  
Ran Yan ◽  
Yu Li ◽  
Jinhui Jeanne Huang

<p>During January 2016 and December 2020, eastern and southern China including Shanghai experienced a rapid drop in temperatures along with snow. This cold wave which also had a severe impact on water distribution networks. Leakage of pipe network causes serious economic loss and waste of water resources. Nonetheless, cold wave is not the only factor affecting leakage from a pipe network. There are also other factors including the burial depth of pipes, the materials of pipes, the diameters of pipes, break history and so on. In this work, we use machine learning method and Bayesian distribution regression to explore the relationship between pipe leaks and impact factors. Based on results, risk maps of water distribution networks are generated. This research indicated that which risk factors is important for leakage detection and water loss management of urban water supply network, which can be promising for wide practical applications due to rapid expansion of data.</p>


2017 ◽  
Vol 34 (5) ◽  
pp. 720-732 ◽  
Author(s):  
Indra Gunawan ◽  
Frank Schultmann ◽  
Seyed Ashkan Zarghami

Purpose The purpose of this paper is to review the different interpretations of four key performance indicators of water distribution networks (WDNs): reliability, resilience, redundancy and robustness. It then addresses a range of metrics which have been developed to assess the performance of critical infrastructures, in particular WDNs. Design/methodology/approach The paper provides a comprehensive review and categorization of performance indicators of WDNs. The main focus is on papers addressing performance indicators of water distribution systems, additionally papers on application of complex system approach to critical infrastructures are also included. Findings Due to this complexity, a wide range of interpretation of WDNs performance indicators exists in the literature. This represents a significant impediment toward universally accepted interpretation of these indicators Accurate assessment of WDNs’ performance depends on clear definition of system performance indicators as well as accurate quantifying of these indicators. The application of 18 metrics as a basis for assessing the system performance have been reviewed in this paper and none are particularly significant as standalone values. Combination of these indicators are required to accurately indicate the performance of WDNs. Originality/value The authors believe that this paper can be a valuable source of information for academic researchers and practitioners and suggests a roadmap for future works.


2017 ◽  
Vol 17 (6) ◽  
pp. 1663-1672 ◽  
Author(s):  
E. Forconi ◽  
Z. Kapelan ◽  
M. Ferrante ◽  
H. Mahmoud ◽  
C. Capponi

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.


Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1841
Author(s):  
Miguel Capelo ◽  
Bruno Brentan ◽  
Laura Monteiro ◽  
Dídia Covas

The current paper proposes a novel methodology for near–real time burst location and sizing in water distribution systems (WDS) by means of Multi–Layer Perceptron (MLP), a class of artificial neural network (ANN). The proposed methodology can be systematized in four steps: (1) construction of the pipe–burst database, (2) problem formulation and ANN architecture definition, (3) ANN training, testing and sensitivity analyses, (4) application based on collected data. A large database needs to be constructed using 24 h pressure–head data collected or numerically generated at different sensor locations during the pipe burst occurrence. The ANN is trained and tested in a real–life network, in Portugal, using artificial data generated by hydraulic extended period simulations. The trained ANN has demonstrated to successfully locate 60–70% of the burst with an accuracy of 100 m and 98% of the burst with an accuracy of 500 m and to determine burst sizes with uncertainties lower than 2 L/s in 90% of tested cases and lower than 0.2 L/s in 70% of the cases. This approach can be used as a daily management tool of water distribution networks (WDN), as long as the ANN is trained with artificial data generated by an accurate and calibrated WDS hydraulic models and/or with reliable pressure–head data collected at different locations of the WDS during the pipe burst occurrence.


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