Download or read book Modeling and Optimization of Transients in Water Distribution Networks with Intermittent Supply written by Anna Marie Lieb and published by . This book was released on 2016 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt: Much of the world's rapidly growing urban population relies upon water distribution systems to provide treated water through networks of pipes. Rather than continuously supplying water to users, many of these distribution systems operate intermittently, with parts of the network frequently losing pressure or emptying altogether. Such intermittent water supply deleteriously impacts water availability, infrastructure, and water quality for hundreds of millions of people around the world. In this work I introduce the problem of intermittent water supply through the lens of applied mathematics. I first introduce a simple descriptive mathematical model that captures some hydraulic features of intermittency not accounted for by existing water distribution system software packages. I then consider the potential uses of such a model in a variety of optimization examples motivated by real-world applications. In simple test networks, I show how to reduce pressure gradients while the network fills by changing either the inflow patterns or the elevation profile. I also show test examples of using measured data to potentially recover unknown information such as initial conditions or boundary outflows. I then use sensitivity analysis to better understand how various parameters control model output, with an eye to figuring out which parameters are worth measuring most carefully in field applications, and also which parameters may be useful in an optimization setting. I lastly demonstrate some progress in descriptively modeling a real network, both through the introduced mathematical model and through a fluid-mechanics-based method for identifying data where the model is most useful.

Download or read book Advances in Water Distribution Networks written by Giuseppe Pezzinga and published by MDPI. This book was released on 2019-02-28 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Special Issue on Advances in Water Distribution Networks (WDNs) explores four important topics of research in the framework of WDNs, namely simulation and optimization modelling, topology and partitioning, water quality, and service effectiveness. With regard to the first topic, the following aspects are addressed: pressure-driven formulations, algorithms for the optimal location of control valves to minimize leakage, the benefits of water discharge prediction for the remote real time control of valves, and transients generated by pumps operating as turbines. In the context of the second topic, a topological taxonomy of WDNs is presented, and partitioning methods for the creation of district metered areas are compared. In relation to the third topic, the vulnerability to trihalomethane is assessed, and a statistical optimization model to minimize heavy metal releases is presented. Finally, the fourth topic focusses on the estimation of non-revenue water, including leakage and unauthorized consumption, and on the assessment of service under intermittent supply conditions.

Download or read book Advances in Water Distribution Networks written by Enrico Creaco and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Special Issue on Advances in Water Distribution Networks (WDNs) explores four important topics of research in the framework of WDNs, namely simulation and optimization modelling, topology and partitioning, water quality, and service effectiveness. With regard to the first topic, the following aspects are addressed: pressure-driven formulations, algorithms for the optimal location of control valves to minimize leakage, the benefits of water discharge prediction for the remote real time control of valves, and transients generated by pumps operating as turbines. In the context of the second topic, a topological taxonomy of WDNs is presented, and partitioning methods for the creation of district metered areas are compared. In relation to the third topic, the vulnerability to trihalomethane is assessed, and a statistical optimization model to minimize heavy metal releases is presented. Finally, the fourth topic focusses on the estimation of non-revenue water, including leakage and unauthorized consumption, and on the assessment of service under intermittent supply conditions.

Download or read book Advances in Water Distribution Networks written by and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Special Issue on Advances in Water Distribution Networks (WDNs) explores four important topics of research in the framework of WDNs, namely simulation and optimization modelling, topology and partitioning, water quality, and service effectiveness. With regard to the first topic, the following aspects are addressed: pressure-driven formulations, algorithms for the optimal location of control valves to minimize leakage, the benefits of water discharge prediction for the remote real time control of valves, and transients generated by pumps operating as turbines. In the context of the second topic, a topological taxonomy of WDNs is presented, and partitioning methods for the creation of district metered areas are compared. In relation to the third topic, the vulnerability to trihalomethane is assessed, and a statistical optimization model to minimize heavy metal releases is presented. Finally, the fourth topic focusses on the estimation of non-revenue water, including leakage and unauthorized consumption, and on the assessment of service under intermittent supply conditions.

Download or read book Water Distribution written by Stephen Nyende-Byakika and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling Transient Flow in Intermittent Water Supply System written by Xin Zhang (S.M.) and published by . This book was released on 2017 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: Water distribution systems in cities throughout South Asia (and many other countries) only supply water on an intermittent basis (currently averaging less than 5hrs/day in most Indian cities). Intermittent Water Supply (IWS) creates inequities in water availability and carries public health risks associated with the ingress of contaminants from the surrounding ground through flaws in the aged piping systems. It is a major challenge to upgrade from intermittent to continuous water supply (CWS) as this involves an increase in the operating water pressures which promotes higher rates of leakage. There are currently no reliable computational models for characterizing the transient hydraulic behavior of IWS systems (including pipe filling and draining events) and hence, it is difficult to understand and control IWS systems. In a recent PhD thesis, Lieb (2015) developed an open-source code to solve the dynamics of IWS pipe networks through finite volume solution of the governing 1-D Saint Venant equations using the Preismann slot approximation. The current thesis extends and refines the algorithms proposed by Lieb to enable more robust simulations for pipe networks. Specific modification include algorithms for dry pipes and three-pipe junctions. The thesis proposes a new algorithm for representing the conservation of fluid mass, momentum and energy at a three-pipe junction which is validated by comparing computed loss coefficients with measured data reported in the literature. The research also validates predictions of mixed flow conditions (open-channel and pressured pipe flow conditions) with results from laboratory model tests. The proposed formulation has been applied to simulate a skeletonized pipe network (at a test site in Delhi), where simulations are compared with water pressures during intermittent water supply periods. The proposed analysis represents a first step towards comprehensive modeling of IWS that can be used to improve understanding and control of these systems and to manage the upgrading process for CWS operations.

Download or read book Fluid Transients and Pipeline Optimization Using Genetic Algorithms written by Zhiqiang Zhang and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Millions of dollars are spent each year on water distribution systems. Pipe optimization techniques provide an opportunity for potential savings in costs for water supply systems. These optimization techniques include linear programming, non-linear programming, dynamic programming, enumerative approaches, and genetic algorithms. The former four techniques have been applied to pipe network optimization in the research literature over the last 20 years or so. Genetic algorithms provide a new approach to pipe network optimization. Details of this method are considered in this thesis. A global cost analysis of each component in a water supply system is carried out of the genetic algorithm in order to assess the form of the objective function. Traditionally, the analysis an pipeline systems has focused on the steady state. In the current work, a genetic algorithm optimization model, which uses a probabilistic search procedure that emulates Darwinian natural selection, is coupled with a transient hydraulic simulation model to generate and evaluate trial pipe network designs in search of an optimal solution. A new and powerful penalty function is also developed for pressure violations distinguishing steady state and transient conditions. The genetic algorithm search is applied to a case study which demonstrates its flexibility and the opportunity for significant cost saving offered by this method.

Download or read book Susceptibility of Distribution Systems to Negative Pressure Transients written by Kala K. Fleming and published by American Water Works Association. This book was released on 2006 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Low or negative pressure transients (also called surge or water hammer) create temporary opportunities for external chemical and microbial contaminants at higher pressure to enter the water distribution system, creating potential health hazard and potential weakening of distribution pipes, leading to failure. This study investigates how such events as power outages, pump shutdowns, valve operations, main flushing, firefighting, and main breaks can create significant rapid, temporary drops in system pressure. The report offers useful recommendations for using surge models to optimally locate pressure monitors and to minimize the occurrence and impact from low- and negative-pressure transients.

Download or read book Control of Transients in Water Distribution Networks written by Jonas Perolini Castellsague and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, the pressure control in water distribution networks are discussed. First, the importance of efficient pressure control in water distribution networks as well as different pressure control methods are introduced. Then the governing equations for WDNs and pressure reducing valves are derived. Second, an isolated pressure reducing valve is implemented in MATLAB/SIMULINK. Through simulations, the performance of various control algorithm are contrasted. Finally, the control problem of transients in water pressure reducing valves is addressed through a case study. First, a water distribution network model including the transient behavior is developed using MATLAB/SIMULINK for the considered case study. Then, the current case study control strategy is reproduced using a simulator and contrasted with a redesigned control scheme.

Download or read book Water Supply and Water Scarcity written by Vasileios A. Tzanakakis and published by MDPI. This book was released on 2020-11-04 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Book includes selected papers that has been published in the Water journal Special Issue (SI) on Water Supply and Water Scarcity. Moreover, an overview of the SI is included. The papers selected for publication in the SI include review and research papers on water history, on water management issues under water scarcity regimes, on rainwater harvesting, on water quality and degradation, and on climatic variability impacts on water resources. Overall, the issue identify and highlight the main challenges in water sector, and particularly in management and protection of water resources and in use of alternative (non-conventional) water resources, especially in areas with demographic change and climate vulnerability in order to achieve sustainable and secure water supply. Furthermore, general guidelines and possible solutions for an improved and sophisticated water management system are proposed and discussed, such as the adoption of advanced technological solutions and practices that improve water-use efficiency and the use of alternative water resources, to address the growing environmental and health issues and to reduce the emerging conflicts among water users.

Download or read book Modelling of Pressurised Water Supply Networks that May Exhibit Transient Low Pressure Open Channel Flow Conditions written by and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Growing demand for water due to increasing populations, industrialisation and water consuming lifestyles puts stress on existing water supply systems. To cater for the rising demand, water distribution networks are expanded beyond their design capacities and this creates transient “low-pressure-open-channel flow” (LPOCF) conditions. Current water supply models use “demand driven approach” (DDA) methodology which is not able to simulate transient LPOCF conditions, that poses an impediment to management/analysis of pressure-deficient networks.

Download or read book EXPERIMENTAL ANALYSIS AND COMPUTER SIMULATION OF A LABORATORY SCALE INTERMITTENT WATER SUPPLY SYSTEM written by and published by . This book was released on 2022 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : Intermittent water systems (IWS) are prevalent throughout developing regions of the world. However, few tools exist to predict IWS performance because modeling transient flow is difficult: IWS networks can experience widely fluctuating conditions, ranging from completely empty to completely full (pressurized flow). An experimental IWS, consisting of a 50.75-gallon reservoir, an elevated distribution network, and four outlets was constructed to study the hydraulics of IWS. Three experiments were run on the system that represented two falling-head scenarios and a constant-head scenario. Computer simulation models of the experimental IWS were developed in EPANET 2.2.0 and EPA-SWMM 5.1, which are open-source modeling software for pressured water distribution networks and stormwater conveyance systems, respectively. EPANET 2.2.0 was incapable of representing flows observed in the experiments, likely due to the steady-state assumptions inherent to its global gradient algorithm. However, EPA-SWMM 5.1, which models the propagation of network flows with dynamic wave routing, was able to generate outflow hydrographs that emulated experimental discharge flows. Therefore, it is recommended that further verification be undertaken to validate SWMM's capacity to model IWS systems under a range of hydraulic scenarios. If SWMM can withstand rigorous experimentation, potential may exist for this software to be retooled for the design of IWS.

Download or read book PLANNING FOR INTERMITTENT WATER SUPPLY IN SMALL GRAVITY FED DISTRIBUTION SYSTEMS written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : Intermittent water supply (IWS) is defined as a piped water distribution system that operates in an intermittent fashion, i.e. less than 24 hours per day. Piped water distribution systems are designed to operate with continuous water supply (CWS), meaning the system is operated continuously and maintains positive pressures in the distribution network. Operating a system in an intermittent fashion can cause inequality of access in a water distribution system. It may also result in lower water quality and wear and tear on the system. In the community of Espavé, Panamá a new water system was installed and brought online in 2015. It was designed to operate continuously; however, during the dry season the flow from the spring source drops below the total daily demand of the community. Under this intermittent regime, the system operates differently, causing some community members not to receive water service. Survey and design data were used to model the system, as designed, in EPANET for CWS operation and EPA SWMM for IWS operation. Various trial runs were conducted in SWMM using dynamic flow routing to simulate dry season flow rates, under average and high demand. The model was then divided into two sections in order to isolate higher households from those at lower elevations. These isolated sections were used to develop a staggered operation system for water delivery. Model results indicate that reducing daily usage during the dry season is recommended to prevent intermittency in the system. If demand continues to exceed supply, staggering the delivery to different areas may help to maintain equality in distribution. In the future models for water distribution systems should be developed to simulate IWS.

Download or read book Estimation of Marginal Time in Water Distribution Systems for Valve Closure Considering Transient Flow Effects written by Juan Diego Carvajal Cruz and published by . This book was released on 2017* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Water Distribution Systems (WDS) design problem is frequently carried out under the assumption of steady state flow through the entire network. However, a disruption from steady flow conditions occurs when there is a change in operation of elements in the system as valves or pumps. By undergoing the valve operation properly, the transient pressure changes can be kept under control, minimizing its effects. This research was focused on finding the marginal time by determining a set of optimal closures of a valve at different locations in a WDS. An optimization model was used with valve closure curve and closure time as decision variables; and two objective functions were established: minimization of the Surge Damage Potential Factor (SDPF) and minimization of the Amount of Water Passed (AWP). This model was solved using NSGA II algorithm. The results obtained showed the existence of a Pareto front between SPDF and AWP for the valve operation. This front proved the existence of a marginal time in different WDS with diverse characteristics as maximum flow and existing valves. Determining the marginal time of a WDS can lead to operate different elements properly by minimizing transient flow effects.

Download or read book Water Distribution Networks written by Kalanithy Vairavamoorthy and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Leak Detection written by Stuart Hamilton and published by IWA Publishing. This book was released on 2013-06-30 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ageing infrastructure and declining water resources are major concerns with a growing global population. Controlling water loss has therefore become a priority for water utilities around the world. In order to improve efficiencies, water utilities need to apply good practices in leak detection. Leak Detection: Technology and Implementation assists water utilities with the development and implementation of leak detection programs. Leak detection and repair is one of the components of controlling water loss. In addition, techniques are discussed within this book and relevant case studies are presented. This book provides useful and practical information on leakage issues.

Download or read book Water Transmission and Distribution written by American Water Works Association and published by American Water Works Association. This book was released on 2003 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt: Water distribution systems are made up of pipe, valves and pumps through which treated water is moved from the treament plant to homes, offices, industries, and other consumers. The types of materials and equipment used by each water system are usually governed by local conditions, past practices, and economics. Consequently, drinking water professionals must be knowledgeable about common types of equipment and operating methods that are available. Completely revised and updated, Water transmission and distribution includes information on the following: distribution system design and operation and maintenance ; piping materials ; valves, pumps, and water meters ; water main installation ; backfilling, main testing, and installation safety ; fire hyfrants ; water storage ; water services ; cross-connection control ; motors and engines ; instrumentation and control ; information management and public relations.--Cover page [4].