scholarly journals Online modelling of water distribution systems: a UK case study

2010 ◽  
Vol 3 (1) ◽  
pp. 21-27 ◽  
Author(s):  
J. Machell ◽  
S. R. Mounce ◽  
J. B. Boxall

Abstract. Hydraulic simulation models of water distribution networks are routinely used for operational investigations and network design purposes. However, their full potential is often never realised because, in the majority of cases, they have been calibrated with data collected manually from the field during a single historic time period and, as such, reflect the network operational conditions that were prevalent at that time, and they are then applied as part of a reactive, desktop investigation. In order to use a hydraulic model to assist proactive distribution network management its element asset information must be up to date and it should be able to access current network information to drive simulations. Historically this advance has been restricted by the high cost of collecting and transferring the necessary field measurements. However, recent innovation and cost reductions associated with data transfer is resulting in collection of data from increasing numbers of sensors in water supply systems, and automatic transfer of the data to point of use. This means engineers potentially have access to a constant stream of current network data that enables a new era of "on-line" modelling that can be used to continually assess standards of service compliance for pressure and reduce the impact of network events, such as mains bursts, on customers. A case study is presented here that shows how an online modelling system can give timely warning of changes from normal network operation, providing capacity to minimise customer impact.

2009 ◽  
Vol 2 (2) ◽  
pp. 279-294 ◽  
Author(s):  
J. Machell ◽  
S. R. Mounce ◽  
J. B. Boxall

Abstract. Hydraulic simulation models of water distribution networks are routinely used for operational investigations and network design purposes. However, their full potential is often never realised because, in the majority of cases, they have been calibrated with data collected manually from the field during a single historic time period and, as such, reflect the network operational conditions that were prevalent at that time, and they are then applied as part of a reactive, desktop investigation. In order to use a hydraulic model to assist proactive distribution network management its element asset information must be up to date and it should be able to access current network information to drive simulations. Historically this advance has been restricted by the high cost of collecting and transferring the necessary field measurements. However, recent innovation and cost reductions associated with data transfer is resulting in collection of data from increasing numbers of sensors in water supply systems, and automatic transfer of the data to point of use. This means engineers potentially have access to a constant stream of current network data that enables a new era of "online" modelling that can be used to continually assess standards of service compliance for pressure and reduce the impact of network events, such as mains bursts, on customers. A case study is presented here that shows how an online modelling system can give timely warning of changes from normal network operation, providing capacity to minimise customer impact.


Author(s):  
Jesús Rubén Sánchez-Navarro ◽  
David H. Sánchez ◽  
Carmen J. Navarro-Gómez ◽  
Eduardo Herrera Peraza

Abstract In intermittent drinking water distribution systems, large volumes of the water are wasted due to leaks in the distribution networks. Similarly, user service is not always satisfied in the time required to fill the storage, nor with sufficient pressure. Hence the importance of this study. Measuring the variability of pressure in the distribution network and determining the factors that influence the definition of a sufficient minimum hours of service, is a first step to change to a continuous service 24/7, in order to minimize the volumes of lost water and meet demand. 347 pressure sensors were placed in a network to detect changes in pressure and obtain data for three years. This study presents a new approach to determine the operating policy of the operating agency that provides the service intermittently. Two objectives are pursued: pressure variability – to minimize Leaks – and define the minimum hours of service. The analysis was performed using multivariate statistical techniques, including Principal Component Analysis, Correlation Matrix and ANOVA's, to explore the association between objectives. The results obtained show that the pressure distribution has a Gaussian behavior and that the hours of service has a Poisson distribution.


Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 672 ◽  
Author(s):  
Attilio Fiorini Morosini ◽  
Olga Caruso ◽  
Paolo Veltri

The correct management of Water Distribution Networks (WDNs) allows to obtain a reliable system. When a pipe failure occurs in a network and it is necessary to isolate a zone, it is possible that some nodes do not guarantee service for the users due to inadequate heads. In these conditions a Pressure Driven Analysis (PDA) is the correct approach to evaluate network behavior. This analysis is more appropriate than the Demand Driven Analysis (DDA) because it is known that the effective delivered flow at each node is influenced by the pressure value. In this case, it is important to identify a subset of isolation valves to limit disrupting services in the network. For a real network, additional valves must be added to existing ones. In this paper a new methodological analysis is proposed: it defines an objective function (OF) to provide a measure of the system correct functioning. The network analysis using the OF helps to choose the optimal number of additional valves to obtain an adequate system control. In emergency conditions, the OF takes into account the new network topology obtained excluding the zone where the broken pipe is located. OF values depend on the demand deficit caused by the head decrement in the network nodes for each pipe burst considered. The results obtained for a case study confirm the efficiency of the methodology.


2017 ◽  
Vol 18 (3) ◽  
pp. 767-777 ◽  
Author(s):  
Armando Di Nardo ◽  
Michele Di Natale ◽  
Carlo Giudicianni ◽  
Roberto Greco ◽  
Giovanni Francesco Santonastaso

AbstractWater distribution networks (WDNs) must keep a proper level of service under a wide range of operational conditions, and, in particular, the analysis of their resilience to pipe failures is essential to improve their design and management. WDNs can be regarded as large sparse planar graphs showing fractal and complex network properties. In this paper, the relationship linking the geometrical and topological features of a WDN to its resilience to the failure of a pipe is investigated. Some innovative indices have been borrowed from fractal geometry and complex network theory to study WDNs. Considering all possible network configurations obtained by suppressing one link, the proposed indices are used to quantify the impact of pipe failure on the system's resilience. This approach aims to identify critical links, in terms of resilience, with the help of topological metrics only, and without recourse to hydraulic simulations, which require complex calibration processes and come with a computational burden. It is concluded that the proposed procedure, which has been successfully tested on two real WDNs located in southern Italy, can provide valuable information to water utilities about which pipes have a significant role in network performance, thus helping in their design, planning and management.


Author(s):  
Sornsiri Sriboonnak ◽  
Phacharapol Induvesa ◽  
Suraphong Wattanachira ◽  
Pharkphum Rakruam ◽  
Adisak Siyasukh ◽  
...  

The formation of trihalomethanes (THMs) in natural and treated water from water supply systems is an urgent research area due to the carcinogenic risk they pose. Seasonal effects and pH have captured interest as potential factors affecting THM formation in the water supply and distribution systems. We investigated THM occurrence in the water supply chain, including raw and treated water from water treatment plants (coagulation, sedimentation, sand filtration, ClO2-disinfection processes, and distribution pipelines) in the Chiang Mai municipality, particularly the educational institute area. The effects of two seasons, rainy (September–November 2019) and dry (December 2019–February 2020), acted as surrogates for the water quality profile and THM occurrence. The results showed that humic acid was the main aromatic and organic compound in all the water samples. In the raw water sample, we found a correlation between surrogate organic compounds, including SUVA and dissolved organic carbon (DOC) (R2 = 0.9878). Four species of THMs were detected, including chloroform, bromodichloromethane, dibromochloromethane, and bromoform. Chloroform was the dominant species among the THMs. The highest concentration of total THMs was 189.52 μg/L. The concentration of THMs tended to increase after chlorination when chlorine dioxide and organic compounds reacted in water. The effect of pH on the formation of TTHMs was also indicated during the study. TTHM concentrations trended lower with a pH ≤ 7 than with a pH ≥ 8 during the sampling periods. Finally, in terms of health concerns, the concentration of TTHMs was considered safe for consumption because it was below the standard (<1.0) of WHO’s Guideline Values (GVs).


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.


2010 ◽  
Vol 107 ◽  
pp. 87-92 ◽  
Author(s):  
José Pérez García ◽  
Antonio Cortés Marco ◽  
Simón Nevado Santos

The main pipes in water distribution systems have, in many cases, an excess of static pressure. This excess of pressure is usually dissipated by means of intermediate reservoirs, pressure-reducing valves or any other device that produces the required energy loss with the aim to adjust the pressure level to the demand pattern of the system. This hydraulic energy can be used to directly drive a mechanical system or to generate electric power. In this type of recovery energy systems, the available hydraulic power is lower than 100 kW (micro-hydro). In this range, the utilization of conventional hydraulic turbines is not economically viable in short-medium time. In micro-hydropower applications the use of standard centrifugal pumps operated in reverse mode as hydraulic turbines (PAT) can be competitive. In this work, several prediction methods and algorithms suggested by different authors were analyzed and compared. Two case study, in the water system distribution of Murcia and Elche are also presented.


2017 ◽  
Vol 18 (3) ◽  
pp. 778-789 ◽  
Author(s):  
S. Parra ◽  
S. Krause ◽  
F. Krönlein ◽  
F. W. Günthert ◽  
T. Klunke

Abstract Pressure reducing valves (PRVs) are used in water distribution networks (WDNs) for pressure control and water loss reduction. In this study, a system composed of a PRV and a pump as turbine (PAT) in combination with intelligent pressure management is proposed and its performance is analysed experimentally. For this, data analysis using hydraulic modelling and extensive experimentation for a case study in Germany was performed. During the laboratory tests, the pressure at the critical point of the system could be successfully maintained at the selected value at variable discharges during a characteristic day, as a result of the advanced pressure modulation. Additionally, up to 2.3 kW of electrical energy were recovered, when the applied PAT was operating under full load, with a maximum total net system efficiency of 40%. Furthermore, the proposed pressure management was found to increase the water savings by up to 16% compared to conventional PRVs. This study concludes that the PAT-PRV-system may be suitable in WDNs with high differences in altitude, high operational pressures and high demand variability. For its application, the benefits and the investment costs, as well as the seasonal flow and pressure variations in the WDN should be analysed in detail.


Author(s):  
Isaac G. Musaazi ◽  
Jotham I. Sempewo ◽  
Mohammed Babu ◽  
Nicholas Kiggundu

Abstract Fluctuations in the network pressure of water supply systems affect hydraulic performance and water meter accuracy. The development of metering error curves requires steady-state conditions which are extremely rare in water distribution systems characterized by intermittent supply. Simple deterministic models are suggested and developed from monthly data collected over a 4-year period (2010–2014) for three most dominant meter models (Models 1–3) in the Kampala Water Distribution System (KWDS), Uganda. This study combines pressure and billing information at the same time to understand metering accuracy. Results showed that metering accuracy increased by 4.2, 8.4 and 2.9% when pressure was increased from 10 to 50 m for Models 1–3, respectively. Age did not influence the impact of pressure on meter accuracy. The most sensitive parameter in the model was the meter age. Metering accuracy was relatively constant after a period of 5 years. The least sensitive parameter was the working pressure which caused a slight change to the annual billed volume. The ability of the model to accurately predict the meter registration degenerated with an increasing annual billed volume. Model 2 meters were the best performing and probably the most suitable meters in the KWDS.


2013 ◽  
Vol 13 (4) ◽  
pp. 889-895 ◽  
Author(s):  
C. Lenzi ◽  
C. Bragalli ◽  
A. Bolognesi ◽  
S. Artina

The collection and distribution of drinking water resources generally require large quantities of energy, that vary according to factors related to the characteristics of the served area, as well as to design and management choices. Energy intensity indicators (energy per unit of volume) are insufficient to assess the weight of different factors that affect the energy consumption and appear not suitable for the comparison of different water supply systems. The key step of this work is to define a methodology for assessing the energy efficiency of water supply systems. In particular, water losses in water distribution systems, generally assessed in relation to the quantity of high quality water dispersed in the environment, are herein considered in relation to their energy content. In addition to the evaluation of energy balance using the approach proposed by Enrique Cabrera et al. in ‘Energy audit of water networks’ (see J. Water Res. Plan. Manage.136 (6), 669–677) an overall efficiency indicator WSEE (Water Supply Energy Efficiency) is then proposed. Its decomposition finally leads to the definition of further indicators, which may help to assess how the structure of the network, leakage rate and/or pumps affect the energy efficiency of the water system. Such indicators can be used to compare different water supply systems and to identify the impact of individual interventions. The proposed energy analysis was applied to two case studies in Northern Italy.


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