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Masuda, Naoki, e Fanlin Meng. "Dynamical stability of water distribution networks". Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 475, n.º 2230 (outubro de 2019): 20190291. http://dx.doi.org/10.1098/rspa.2019.0291.
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Water distribution networks are hydraulic infrastructures that aim to meet water demands at their various nodes. Water flows through pipes in the network create nonlinear dynamics on networks. A desirable feature of water distribution networks is high resistance to failures and other shocks to the system. Such threats would at least transiently change the flow rate in various pipes, potentially undermining the functionality of the whole water distribution system. Here we carry out a linear stability analysis for a nonlinear dynamical system representing the flow rate through pipes that are interconnected through an arbitrary pipe network with reservoirs and consumer nodes. We show that the steady state is always locally stable and develop a method to calculate the eigenvalue that corresponds to the mode that decays the most slowly towards the equilibrium, which we use as an index for resilience of the system. We show that the proposed index is positively correlated with the recovery rate of the pipe network, which was derived from a realistic and industrially popular simulator. The present analytical framework is expected to be useful for deploying tools from nonlinear dynamics and network analysis in the design, resilience management and scenario testing of water distribution networks.
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Ahn, J. C., S. W. Lee, G. S. Lee e J. Y. Koo. "Predicting water pipe breaks using neural network". Water Supply 5, n.º 3-4 (1 de novembro de 2005): 159–72. http://dx.doi.org/10.2166/ws.2005.0096.
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The relationships between pipe breaks of service pipes and mains and several factors were examined. Historical pipe breaks, and water and soil temperatures were also modeled by an artificial neural network to predict pipe breaks for efficient management and maintenance of the pipe networks. It was observed that the breaks of pipes increased after the temperatures of water and soil crossed in spring and fall. The pipe breaks were closely related to water and soil temperature, especially mains were affected more than service pipes. The fittings and valves were susceptible to the temperatures and needed to take measures for preventing breaks. The prediction of the pipe breaks by the ANN model built had a good performance except that the sensitivity was not good when the pipe breaks rapidly increased or decreased. The ANN model gave a good performance and was to be useful to predict the patterns of pipe breaks on a seasonal basis.
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Young, Brian. "Analysis and optimisation of looped water distribution networks". Journal of the Australian Mathematical Society. Series B. Applied Mathematics 41, n.º 4 (abril de 2000): 508–26. http://dx.doi.org/10.1017/s0334270000011796.
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AbstractA three stage procedure for the analysis and least-cost design of looped water distribution networks is considered in this paper. The first stage detects spanning trees and identifies the true global optimum for the system. The second stage determines hydraulically feasible pipe flows for the network by the numerical solution of a set of non-linear simultaneous equations and shows that these solutions are contained within closed convex polygonal regions in the solution space bounded by singularities resulting from zero flows in individual pipes. Ideal pipe diameters, consistent with the pipe flows and the constant velocity constraint adopted to prevent the system degenerating into a branched network, are selected and costed. It is found that the most favourable optimum is in the vicinity of a vertex in the solution space corresponding to the minimum spanning tree. In the third stage, commercial pipes are specified and the design finalised. Upper bound formulae for the number of spanning trees and hydraulically feasible solutions in a network have also been proposed. The treatment of large networks by a heuristic procedure is described which is shown to result in significant economies compared with designs obtained by non-linear programming.
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Teleszewski, Tomasz Janusz, Dorota Anna Krawczyk e Antonio Rodero. "Reduction of Heat Losses Using Quadruple Heating Pre-Insulated Networks: A Case Study". Energies 12, n.º 24 (10 de dezembro de 2019): 4699. http://dx.doi.org/10.3390/en12244699.
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The paper presents an analysis of heat loss and reductions of annual emissions of air pollutants of a quadruple pre-insulated heating network by comparing this solution with the existing pre-insulated network consisting of four pre-insulated single pipes and the variant consisting of two twin pipe pre-insulated. For calculations, an existing heating network located in central Poland was adopted, where heat is transported for heating purposes of buildings and domestic hot water with circulation of domestic hot water through four separate pre-insulated underground pipes. The idea of the construction of four pre-insulated pipes presented in the paper consists in the location of four steel pipes in a common round thermal insulation, which perform the role of heat transport for heating purposes in multi-family buildings (supply and return) and two pipes transporting hot water (a pipe with domestic hot water with circulation). In Poland, heating pipes used in multi-family housing have a larger diameter compared to domestic hot water pipes, which is why standard twin pipe heating pipes have been used in the construction of four pre-insulated networks, in which the domestic hot water pipe has been added to the thermal insulation and circulation of domestic hot water. In order to determine heat losses, a simplified two-dimensional model of conductive heat transfer was developed using Fortran to create a computer program. The results of numerical simulations show that the use of twin pipes for the construction of pre-insulated quadruple networks has contributed to a significant reduction in heat loss in relation to the existing single pre-insulated network (up to 57.1%), while reducing the thermal insulation field of the cross-section of the pre-insulated pipe by 21.4%.
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Hooda, Nikhil, e Om Damani. "Inclusion of tank configurations as a variable in the cost optimization of branched piped-water networks". Drinking Water Engineering and Science 10, n.º 1 (9 de junho de 2017): 39–44. http://dx.doi.org/10.5194/dwes-10-39-2017.
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Abstract. The classic problem of the capital cost optimization of branched piped networks consists of choosing pipe diameters for each pipe in the network from a discrete set of commercially available pipe diameters. Each pipe in the network can consist of multiple segments of differing diameters. Water networks also consist of intermediate tanks that act as buffers between incoming flow from the primary source and the outgoing flow to the demand nodes. The network from the primary source to the tanks is called the primary network, and the network from the tanks to the demand nodes is called the secondary network. During the design stage, the primary and secondary networks are optimized separately, with the tanks acting as demand nodes for the primary network. Typically the choice of tank locations, their elevations, and the set of demand nodes to be served by different tanks is manually made in an ad hoc fashion before any optimization is done. It is desirable therefore to include this tank configuration choice in the cost optimization process itself. In this work, we explain why the choice of tank configuration is important to the design of a network and describe an integer linear program model that integrates the tank configuration to the standard pipe diameter selection problem. In order to aid the designers of piped-water networks, the improved cost optimization formulation is incorporated into our existing network design system called JalTantra.
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Levinas, Daniel, Gal Perelman e Avi Ostfeld. "Water Leak Localization Using High-Resolution Pressure Sensors". Water 13, n.º 5 (25 de fevereiro de 2021): 591. http://dx.doi.org/10.3390/w13050591.
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A new method for identifying a leaking pipe within a pressurized water distribution system is presented. This novel approach utilizes transient modeling to analyze water networks. Urban water supply networks are important infrastructure that ensures the daily water consumption of urban residents and industrial sites. The aging and deterioration of drinking water mains is the cause of frequent burst pipes, thus making the detection and localization of these bursts a top priority for water distribution companies. Here we describe a novel method based on transient modeling of the water network and produces high-resolution pressure response under various scenarios. Analyzing this data allows the prediction of the leaking pipe. The transient pressure data is classified as leaking pipes or no leak clusters using the K-nearest neighbors (K-NN) algorithm. The transient model requires a massive computation effort to simulate the network’s performance. The classification model presented good performance with an overall accuracy of 0.9 for the basic scenarios. The lowest accuracy was obtained for interpolated scenarios the model had not been trained on; in this case, the accuracy was 0.52.
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Tabesh, M., J. Soltani, R. Farmani e D. Savic. "Assessing pipe failure rate and mechanical reliability of water distribution networks using data-driven modeling". Journal of Hydroinformatics 11, n.º 1 (1 de janeiro de 2009): 1–17. http://dx.doi.org/10.2166/hydro.2009.008.
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In this paper two models are presented based on Data-Driven Modeling (DDM) techniques (Artificial Neural Network and neuro-fuzzy systems) for more comprehensive and more accurate prediction of the pipe failure rate and an improved assessment of the reliability of pipes. Furthermore, a multivariate regression approach has been developed to enable comparison with the DDM-based methods. Unlike the existing simple regression models for prediction of pipe failure rates in which only few factors of diameter, age and length of pipes are considered, in this paper other parameters such as pressure and pipe depth, are also included. Furthermore, an investigation is carried out on most commonly used mechanical reliability relationships and the results of incorporation of the proposed pipe failure models in the reliability index are compared. The proposed models are applied to a real case study involving a large water distribution network in Iran and the results of model predictions are compared with measured pipe failure data. Compared with the results of neuro-fuzzy and multivariate regression models, the outcomes of the artificial neural network model are more realistic and accurate in the prediction of pipe failure rates and evaluation of mechanical reliability in water distribution networks.
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Neilands, K., M. Bernats e J. Rubulis. "Accumulation and modeling of particles in drinking water pipe fittings". Drinking Water Engineering and Science 5, n.º 1 (3 de setembro de 2012): 47–57. http://dx.doi.org/10.5194/dwes-5-47-2012.
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Abstract. The effect of pipe fittings (mainly T-pieces) on particle accumulation in drinking water distribution networks were shown in this work. The online measurements of flow and turbidity for cast iron, polyethylene and polyvinyl chloride pipe sections were linked with analysis of pipe geometry. Up to 0.29 kg of the total amount mobilized in T-pieces ranging from DN 100/100–DN 250/250. The accumulated amount of particles in fittings was defined as J and introduced into the existing turbidity model PODDS (prediction of discoloration in distribution systems) proposed by Boxall et al. (2001) which describes the erosion of particles leading to discoloration events in drinking water network viz sections of straight pipes. However, this work does not interpret mobilization of particles in pipe fittings which have been considered in this article. T-pieces were the object of this study and depending of the diameter or daily flow velocity, the coefficient J varied from 1.16 to 8.02. The study showed that pipe fittings act as catchment areas for particle accumulation in drinking water networks.
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Aklog, D., e Y. Hosoi. "Reliability-based optimal design of water distribution networks". Water Supply 3, n.º 1-2 (1 de março de 2003): 11–18. http://dx.doi.org/10.2166/ws.2003.0080.
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Maintaining network loops, and hence attaining acceptable system reliability, has been a challenge in the optimal design of water distribution networks. Aimed at a possible solution to the problem, this paper has two objectives: to introduce a new reliability-based optimal design formulation and a model, and to examine the effect of specifying minimum allowable pipe sizes during least-cost designs on system reliability. System reliability is estimated using the minimum cut-set method, but instead of using the mechanical failure probabilities of pipes, weighted failure probabilities are calculated by considering the ratio of the actual supply to demand. One of the salient features of this study and the new reliability-based design model in particular, is that a pressure-driven network simulation model is used to determine the actual supply at each demand point when a component fails. A simplified two-loop network is used to illustrate the performance of the new model and to study the effect of specifying minimum allowable pipe sizes. The results obtained show that the new model preserves loops and results in a system with better reliability; and, if appropriate, minimum allowable pipe sizes are specified in the least-cost design, a required reliability can be attained with a reasonably low cost.
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Wols, Bas, Andreas Moerman, Peter Horst e Karel van Laarhoven. "Prediction of Pipe Failure in Drinking Water Distribution Networks by Comsima". Proceedings 2, n.º 11 (6 de agosto de 2018): 589. http://dx.doi.org/10.3390/proceedings2110589.
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Comsima is a mechanical model that calculates stresses and joint rotations in drinking water distribution pipes based upon several loadings on the pipe (soil, traffic, water pressure, differential settlements). Pipe degradation mechanisms (slow crack growth resistance for PVC and calcium leaching for AC) were added to the model. A comparison with failure registration for an area in the Netherlands using satellite data to determine differential settlements shows that pipes with higher stresses or higher joint rotations in general have a higher failure rate.
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Kang, Won-Hee, Young-Joo Lee e Chunwei Zhang. "Computer-Aided Analysis of Flow in Water Pipe Networks after a Seismic Event". Mathematical Problems in Engineering 2017 (2017): 1–14. http://dx.doi.org/10.1155/2017/2017046.
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This paper proposes a framework for a reliability-based flow analysis for a water pipe network after an earthquake. For the first part of the framework, we propose to use a modeling procedure for multiple leaks and breaks in the water pipe segments of a network that has been damaged by an earthquake. For the second part, we propose an efficient system-level probabilistic flow analysis process that integrates the matrix-based system reliability (MSR) formulation and the branch-and-bound method. This process probabilistically predicts flow quantities by considering system-level damage scenarios consisting of combinations of leaks and breaks in network pipes and significantly reduces the computational cost by sequentially prioritizing the system states according to their likelihoods and by using the branch-and-bound method to select their partial sets. The proposed framework is illustrated and demonstrated by examining two example water pipe networks that have been subjected to a seismic event. These two examples consist of 11 and 20 pipe segments, respectively, and are computationally modeled considering their available topological, material, and mechanical properties. Considering different earthquake scenarios and the resulting multiple leaks and breaks in the water pipe segments, the water flows in the segments are estimated in a computationally efficient manner.
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Sarbu, Ioan, e Gabriel Ostafe. "Determination of Neutral Point in Water Distribution Network Pipes with Variable Discharge on Route". Advanced Materials Research 909 (março de 2014): 428–32. http://dx.doi.org/10.4028/www.scientific.net/amr.909.428.
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Distribution networks are an essential part of all water supply systems. Distribution system costs within any water supply scheme may be equal to or greater than 60% of the entire cost of the project. The reliability of supply is much greater in the case of looped networks. The pipe networks have concentrated outflows or uniform outflow along the length of each pipe. In some pipes with variable discharge of a looped distribution network, water velocity could be reversed between its extremities. Thus, it is a water stall point denominated neutral point in which the discharge is null. In this paper a mathematical model for the determination of water stall point location in the pipes with distributed consumption is developed. This model has been implemented in a computer program for PC microsystems. Numerical example will be presented to demonstrate the accuracy and efficiency of the proposed model.
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Boxall, J. B., P. J. Skipworth e A. J. Saul. "Aggressive flushing for discolouration event mitigation in water distribution networks". Water Supply 3, n.º 1-2 (1 de março de 2003): 179–86. http://dx.doi.org/10.2166/ws.2003.0101.
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Discolouration is one of the biggest causes of customer complaint associated with potable water. The flushing of systems has been widely identified as an appropriate pro-active means of removing material from distribution networks and hence controlling discolouration. Such flushing involves creating aggressive hydraulic forces within the network such that the materials that contribute to discolouration are mobilised and removed. Understanding of the causes and mechanisms leading to discolouration are poor. Previous work has been presented on the characterisation of material and particles collected at hydrants during flushing trials in the UK. From this data it was hypothesised that the materials causing discolouration originated from cohesive layers on pipe walls, and that once disturbed the material is maintained as a permanent suspension even under the most quiescent of networks conditions. The work presented in this paper attempts to validate the hypothesis that the discolouration materials originate from cohesive layers, and investigate the nature and variability of such layers within live distribution systems. The study involved the aggressive flushing of a long discrete length of cast iron pipe with known discolouration problems. The results showed a progressive generation of material over the length of the pipe, confirming that the material originated from a uniformly distributed cohesive source. This was followed by a sequence of flushing operations for the systematic cleaning of a complex network area, encompassing a mixture of pipe materials and ages. All measured turbidity traces showed exponential decay with time. Such exponential decay may be predicted by a model based on a change in layer strength with degree of erosion. Hydraulic forces appear to be a key factor governing the availability and mobilisation of material. Iron is the dominant material mobilised from all the pipes. There is no direct trend between the amount or the composition of the material mobilised from the different pipes.
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Chung, Gunhui, e Won Soo Ohk. "Development of the Urban Water Balance Model by Linking Water Distribution and Sewer Networks". Journal of the Korean Society of Hazard Mitigation 20, n.º 6 (31 de dezembro de 2020): 369–77. http://dx.doi.org/10.9798/kosham.2020.20.6.369.
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Due to urban overcrowding, the population density of residential areas and water use per unit are increasing. Therefore, it is necessary to study the flow of water supplied to cities and to improve the healthy circulation of urban water. This study used Modelica, a non-causal analytical program. Using Open Modelica, the researchers constructed a model linking water distribution and sewerage, as the basis of a balanced urban water model. Using the programmer's toolkit provided by EPA-NET and EPA-SWMM, which are commonly used to simulate the existing water supply and sewage pipe networks, Open Modelica-based water distribution networks and sewage pipe networks can be connected and simulated based on the customer block. A model was built so that 90% of the hourly water consumption supplied to the water supply pipe network can be automatically introduced into the sewage pipe network. If a matching table is constructed to connect the nodes of the water supply pipe network and the sewer pipe network, the nodes will reflect in the graphical user interface (GUI) developed in Open Modelica. It was developed to enable modification of links, pumps, tanks, and valves. The 48-hour water supply was simulated using the developed model, and it was confirmed that water supply and sewage networks were successfully connected. In the future, we plan to develop a more expanded and realistic urban water circulation model by considering additional urban water circulation factors, such as sewage treatment, water reuse, rainwater use, storm runoff, and low-impact development facilities. Through this study, it was confirmed that Modelica can simulate changes in the system over time. Since it is a formula-based non-causal simulation language, it is possible to establish and reuse relationships between blocks through block-by-block development of urban water circulation elements. It is expected to contribute to the visualization and concretization of future urban water circulation models.
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Vlase, Sorin, Marin Marin, Maria Luminița Scutaru, Dumitru Daniel Scărlătescu e Carol Csatlos. "Study on the Mechanical Responses of Plastic Pipes Made of High Density Polyethylene (HDPE) in Water Supply Network". Applied Sciences 10, n.º 5 (1 de março de 2020): 1658. http://dx.doi.org/10.3390/app10051658.
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This paper studies the mechanical behavior of high-density polyethylene (HDPE), from which the pipes used for water transport in water supply networks are manufactured. The study was generated by the practical problem of replacing and modernizing a water network of a city with 300,000 inhabitants. Of the numerous problems that have arisen and been solved by the group of researchers, only those referring to the mechanical behavior of the materials used for pipes are presented. HDPE, which is a thermoplastic material, is suitable for manufacturing the pipes used in water supply networks, having many advantages. Data on the mechanical properties of the material of which the pipe and elbow are made is obtained experimentally. The work involved the main steps required to design a water network, but the subject is not exhausted. The stresses in the polyethylene pipe are determined in two cases: buried in the ground and supported in a concrete massif. Thus, by calculation, the advantage offered by the second solution is justified. The crack of the pipes manufactured from HDPE is studied, taking into account the classical model used in the cracking process. A simulation of pipes and elbows cracking was made. The results obtained via MEF are useful for the users of the networks.
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Kusuma, Angga Budi. "Pemanfaatan Sistem Informasi Geografis Dalam Evaluasi Kinerja Penyediaan Air Minum Perpipaan (Studi Kasus Sistem Lendah Kabupaten Kulon Progo)". JURNAL GEOGRAFI 10, n.º 1 (2 de janeiro de 2018): 14. http://dx.doi.org/10.24114/jg.v10i1.8629.
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Abstrak Evaluasi jaringan perpipaan merupakan bagian dari evaluasi kinerja penyediaan air minum. Sistem Informasi Geografis (SIG) memberikan informasi akurat mengenai informasi kebumian dan integrasinya dengan Epanet memberikan efisiensi dalam evaluasi jaringan perpipaan. Jaringan Perpipaan Sistem Lendah merupakan jaringan distribusi air minum dengan sistem pompa-gravitasi dengan sumber air baku Sungai Progo. Hasil analisis menunjukan bahwa Sistem Lendah mampu menyediakan kebutuhan air minum selama 24 jam. Sisa tekanan air di beberapa lokasi sangat tinggi diatas persyaratan menyebebabkan rentan kebocoran. Kecepatan aliran di beberapa ruas pipa masih dibawah kecepatan yang dipersyaratkan menyebabkan potensi pengendapan dalam pipa. Beberapa solusi dapat digunakan untuk mengatasi permasalahan tersebut dengan mengganti jenis pipa, mengganti diameter pipa sesuai dengan kriteria, menambahkan bak pelepas tekanan (BTP) atau pressure reducing valve (valve) untuk mengurangi sisa tekanan di beberapa titik. Kata Kunci: Sistem Informasi Geografis, Epanet, Sistem Lendah, Jaringan PerpipaanAbstractPipe network evaluation is a part of evaluation of drinking water supply performance. Geographic Information System (GIS) provides accurate information about earth and its integration with Epanet gives eficiency in pipe network evaluation. Lendah system pipe network is drinking water distribution networks with pump-gravitation system and water of Progo River as the water source. The analyst shows that Lendah System is capable of providing drinking water needs 24 hours daily.The remaining water pressure in several locations are exceeded standard causing leakage vulnerability. Water velocity of several pipe segments is below required velocity. Several solutions could be taken to solve those problems they change pipe type, change pipe diameter suited to standard, add pressure release tube (PRT) or pressure reducing valve (valve) to reduce remaining pressure in several nodes. Keywords: Geographic Information Systems, Epanet, Lendah System, Pipe Network
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Fernández-Pato, J., e P. García-Navarro. "Finite volume simulation of unsteady water pipe flow". Drinking Water Engineering and Science 7, n.º 2 (21 de agosto de 2014): 83–92. http://dx.doi.org/10.5194/dwes-7-83-2014.
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Abstract. The most commonly used hydraulic network models used in the drinking water community exclusively consider fully filled pipes. However, water flow numerical simulation in urban pipe systems may require to model transitions between surface flow and pressurized flow in steady and transient situations. The governing equations for both flow types are different and this must be taken into account in order to get a complete numerical model for solving dynamically transients. In this work, a numerical simulation tool is developed, capable of simulating pipe networks mainly unpressurized, with isolated points of pressurization. For this purpose, the mathematical model is reformulated by means of the Preissmann slot method. This technique provides a reasonable estimation of the water pressure in cases of pressurization. The numerical model is based on the first order Roe's scheme, in the frame of finite volume methods. The novelty of the method is that it is adapted to abrupt transient situations, with subcritical and supercritical flows. The validation has been done by means of several cases with analytic solutions or empirical laboratory data. It has also been applied to some more complex and realistic cases, like junctions or pipe networks.
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Herstein, L. M., e Y. R. Filion. "Life-cycle assessment of common water main materials in water distribution networks". Journal of Hydroinformatics 13, n.º 3 (22 de novembro de 2010): 346–57. http://dx.doi.org/10.2166/hydro.2010.127.
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This paper examines the economy-wide environmental impacts linked to the manufacturing of PVC and ductile iron (DI) pipes, steel tanks, and to the generation of electricity for pumping in water distribution network optimization. The non-dominated sorting genetic algorithm (NSGA-II) is used to generate Pareto-optimal solutions of the benchmark ‘Anytown’ network expansion problem. Selected Pareto-optimal solutions of the ‘Anytown’ network are evaluated with an economic input–output life-cycle assessment (EIO-LCA) and 14 environmental measures on air emissions, non-renewable energy use and environmental releases. The major findings suggest that DI and PVC pipe manufacturing and electricity generation activities (for pumping) have higher environmental impacts than steel tank manufacturing and construction activities in the ‘Anytown’ network. The EIO-LCA suggests that DI pipe manufacturing is linked to: (i) carbon monoxide emissions from truck transportation and wholesale trade and (ii) land and underground toxic releases from metal mining activities. PVC pipe manufacturing is linked to: (i) carbon monoxide emissions from truck transportation, (ii) toxic air releases from the plastics material and resin manufacturing sector, (iii) land and underground toxic releases from metal mining and resin manufacturing, and (iv) natural gas use for plastics material and resin manufacturing.
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Shirzad, Akbar, e Massoud Tabesh. "New indices for reliability assessment of water distribution networks". Journal of Water Supply: Research and Technology-Aqua 65, n.º 5 (16 de junho de 2016): 384–95. http://dx.doi.org/10.2166/aqua.2016.091.
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This paper presents new indices to evaluate the reliability of water distribution networks (WDNs) usable in the design, planning and management of these networks. Since the pressure-driven analysis (PDA) of WDNs produces more accurate results than the demand-driven analysis, the new indices are proposed based on the PDA. In the proposed measures, nodal pressures, nodal available discharges and the energy loss per unit length of pipes are considered as the main factors influencing the reliability of WDNs. The introduced network reliability index is a combination of two indices named total nodal reliability and total pipe reliability. These indices are equal to the weighted average of all of the nodal and pipe reliabilities, respectively. A sample network is used to evaluate the new proposed index and some of the available indices and to compare their efficiencies in assessing the reliability of WDNs. The results show that the new proposed index is more efficient and outperforms the others. The introduced index is normalized and is independent of the WDN size. This index considers the qualitative aspects of WDNs besides the hydraulic aspects in evaluating reliability.
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Suribabu, C. R. "Differential evolution algorithm for optimal design of water distribution networks". Journal of Hydroinformatics 12, n.º 1 (1 de setembro de 2009): 66–82. http://dx.doi.org/10.2166/hydro.2010.014.
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Water distribution networks are considered as the most important entity in the urban infrastructure system and need huge investment for construction. The inherent problem associated with cost optimisation in the design of water distribution networks is due to the nonlinear relationship between flow and head loss and availability of the discrete nature of pipe sizes. In the last few decades, many researchers focused on several stochastic methods of optimisation algorithms. The present paper is focused on the Differential Evolution algorithm (henceforth referred to as DE) and utilises a similar concept as the genetic algorithm to achieve a goal of optimisation of the specified objective function. A simulation–optimisation model is developed in which the optimization is done by DE. Four well-known benchmark networks were taken for application of the DE algorithm to optimise pipe size and rehabilitation of the water distribution network. The findings of the present study reveal that DE is a good alternative to the genetic algorithm and other heuristic approaches for optimal sizing of water distribution pipes.
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Hoțupan, Anca, Roxana Mare e Adriana Hădărean. "Water Loss Reduction in Water Distribution Networks. Case Study". Journal of Applied Engineering Sciences 9, n.º 1 (1 de maio de 2019): 73–80. http://dx.doi.org/10.2478/jaes-2019-0009.
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Abstract Water losses on the potable water distribution networks represent an important issue; on the one hand, water loss does not bring money and on the other hand, they modify water flow and pressure distribution on the entire system and this can lead to a cut-off of the water supply. A stringent monitoring of the water distribution network reduces considerably the water losses. The appearance of a leakage inside the distribution network is inevitable in time. But very important is its location and repair time – that are recommended to be as short as possible. The present paper analyses the hydraulic parameters of the water flow inside a supply pipe of a looped network that provides potable water for an entire neighbourhood. The main goals are to optimize these parameters, to reduce water losses by rigorous monitoring and control of the service pressure on the supply pipe and to create a balance between pressure and water flow. The presented method is valid for any type of distribution network, but the obtained values refer strictly to the analysed potable water distribution looped network.
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Pawar, Mukund M., e Nitin P. Sonaje. "Converting Traditional Water Supply Network Into 24x7, using Water GEMS to Optimize Design". International Journal of Recent Technology and Engineering 10, n.º 1 (30 de maio de 2021): 280–84. http://dx.doi.org/10.35940/ijrte.a5937.0510121.
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Water is all-natural driving force. Entire world struggles to preserve it. Given that India is among the top 12 water poor countries, water wastage is a critical issue for us. India's population is increasing day by day and thus the demand for water is continuously increasing. This growing demand can be met through an efficient water distribution network which can be designed using modern hydraulic software such as Water GEMS. Using the Water GEMS software Pandharpur city is selected to convert existing water supply system into 24 * 7 continuous water supply systems. The largest investment is the pipes used in the water distribution system. The design, modeling and optimization of pipes in water supply system from an economic point of view are very important. Therefore optimal pipe network design for converting existing network into 24x7 water supply system networks is carried out in this paper to reduce the cost using WaterGEM software. Study of the existing water supply network system for one zone (Ambika Nagar Zone10) is initially carried out from the Pandharpur area. The effect on demand, head loss gradient, and pressure development of the forecasted population is studied. In addition, cost optimization of the pipe network for the proposed 24x7 water supply system is carried out using a genetic algorithms Darwin optimization approach.
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Wąsowski, Jacek, Dariusz Kowalski, Beata Kowalska, Marian Kwietniewski e Małgorzata Zawilska. "Water Quality Changes in Cement-Lined Water Pipe Networks". Applied Sciences 9, n.º 7 (30 de março de 2019): 1348. http://dx.doi.org/10.3390/app9071348.
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This research focused on a model setup fed with underground water pumped into a water supply network. The scope of the research included a long- and a short-term stagnation of water in the setup and a water flow of 0.1 m/s. The water supplied into the system gradually lost its corrosive properties and developed calcium carbonate precipitation capability. These processes indicated that cement components migrate from the lining into the water. Apart from the primary components, the presence of the following trace elements was found: iron (399.6 ppb), magnesium (17.8 ppm), zinc (26.9 ppb), barium (22.6 ppb), boron (21.6 ppb), sodium (10.8 ppm), gallium (2.1 ppb). At early stages of the operation, recorded quantities were not significant. Leaching of the trace elements from cement increased after water was chlorinated. In turn, the highest percent increases were observed in the case of zinc (217%), boron (19%) and gallium (12%), whereas the increase for sodium, iron, barium and magnesium in water was insignificant (reaching a few percent). A repeated analysis of samples of stagnant water in the setup showed that most of trace elements were below the detectability level. Final concentrations of all elements identified in the water after its contact with internal cement mortar lining were much lower than the limit values set out for drinking water.
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Kettler, A. J., e I. C. Goulter. "An analysis of pipe breakage in urban water distribution networks". Canadian Journal of Civil Engineering 12, n.º 2 (1 de junho de 1985): 286–93. http://dx.doi.org/10.1139/l85-030.
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The rates of pipe breakage with increasing pipe diameter and times are investigated. Failure rates for cast-iron pipe are found to decrease with increasing diameter. Changes in pipe failure rates for the various modes of failures are examined in detail. Asbestos-cement and cast-iron pipe overall failure rates are found to increase with time, but for different reasons. Analysis of the modes of failure shows that joint failure is predominant for cast-iron pipe systems with bolted and universal joints whereas the predominant mode of failure for asbestos-cement pipe systems is circumferential cracking. Key words: asbestos cement, cast iron, cracking, diameter, failure rate, joint, regression analysis.
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Mallick, Keshaw N., Iftekhar Ahmed, Kevin S. Tickle e Kevin E. Lansey. "Determining Pipe Groupings for Water Distribution Networks". Journal of Water Resources Planning and Management 128, n.º 2 (março de 2002): 130–39. http://dx.doi.org/10.1061/(asce)0733-9496(2002)128:2(130).
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Mohammed, Hadi, Hoese Michel Tornyeviadzi e Razak Seidu. "Modelling the impact of water temperature, pipe, and hydraulic conditions on water quality in water distribution networks". Water Practice and Technology 16, n.º 2 (20 de janeiro de 2021): 387–403. http://dx.doi.org/10.2166/wpt.2021.002.
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Abstract Identifying and controlling the drivers of change in the quality of water within distribution systems requires a comprehensive understanding of the individual and interactive effects of relevant factors. This article examines the impact of water temperature, pipe characteristics, and hydraulic conditions on the microbiological, physical, and chemical parameters of water quality in the distribution network using Bayesian Dirichlet process mixture of linear models and random forest method. The study was based on a database of the distribution network for the city of Ålesund in Norway and records of water quality data measured at seven different locations in the network from 2013 to 2019. In both modelling approaches applied, temperature was identified as the main factor that controls the microbiological stability of water in the network. From the minimum to the maximum values of temperature in the pipes (3.35 °C–11.14 °C respectively), the probabilities of occurrence of bacteria in water increased from 0.36 to 0.95. Temperature was also shown to be an important factor that affects the chemical parameters of water quality (pH, alkalinity and electrical conductivity). Among the input parameters included in this study, concentration of residual chlorine was shown to have the strongest growth-inhibiting effect on Total Bacteria in the pipes. The results further showed that changes in the hydraulic conditions in the pipes (residence time and flow) were among the most important determinants of the physical, chemical and microbiological quality of water in the distribution network. The random forest models assigned minimal importance to the pipe characteristics and conditions on changes in the water quality parameters. However, the Bayesian models revealed that these parameters have significant impact on the quality of water in the pipes.
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Giraldo-González, Mónica Marcela, e Juan Pablo Rodríguez. "Comparison of Statistical and Machine Learning Models for Pipe Failure Modeling in Water Distribution Networks". Water 12, n.º 4 (17 de abril de 2020): 1153. http://dx.doi.org/10.3390/w12041153.
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The application of statistical and Machine Learning models plays a critical role in planning and decision support processes for efficient and reliable Water Distribution Network (WDN) management. Failure models can provide valuable information for prioritizing system rehabilitation even in data scarcity scenarios, such as developing countries. Few studies have analyzed the performance of more than two models, and examples of case studies in developing countries are insufficient. This study compares various statistical and Machine Learning models to provide useful information to practitioners for the selection of a suitable pipe failure model according to information availability and network characteristics. Three statistical models (i.e., Linear, Poisson, and Evolutionary Polynomial Regressions) were used for failure prediction in groups of pipes. Machine Learning approaches, particularly Gradient-Boosted Tree (GBT), Bayes, Support Vector Machines and Artificial Neuronal Networks (ANNs), were compared in predicting individual pipe failure rates. The proposed approach was applied to a WDN in Bogotá (Colombia). The statistical models showed an acceptable performance (R2 between 0.695 and 0.927), but the Poisson Regression was the most suitable for predicting failures in pipes with lower failure rates. Regarding Machine Learning models, Bayes and ANNs exhibited low performance in the prediction of pipe failure condition. The GBT approach had the best performing classifier.
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Li, Zhen, Zijian Lin, Shilei Lyu, Zhiwei Wei e Heqing Huang. "Tree-Type Irrigation Pipe Network Planning and Design Method Using ICSO-ASV". Water 12, n.º 7 (14 de julho de 2020): 1985. http://dx.doi.org/10.3390/w12071985.
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Research on tree-type irrigation pipe networks is an important component of agricultural water-saving projects. The optimal design of tree-type irrigation pipe networks is a key aspect regarding the profitability of irrigated agriculture. Meanwhile, swarm intelligence optimization algorithms have good computational ability and can be applied to solve many optimization problems in agricultural engineering. To identify the lowest investment cost for a pipe network, this study defined the concept of an upper water node to ensure the connectivity of tree-type irrigation pipe networks, and therefore, improve the pipe network planning model without using preliminary network connection diagrams. In addition, this study proposed an improved chicken swarm optimization algorithm (Improved Chicken Swarm Optimization using Adaptive Search and Variation, ICSO-ASV), which was applied to solve 12 test functions of different dimensions. The test results show that, compared to the traditional chicken swarm algorithm and other algorithms in the control group, the ICSO-ASV algorithm could effectively improve the global search capability. Finally, the ICSO-ASV algorithm was used to plan and design 15-node and 40-node pipe networks. The calculation results show that the average investment costs of the two pipe networks generated by the ICSO-ASV algorithm were 42.20% and 31.09% lower than those generated by the traditional chicken swarm algorithm, which further verified the feasibility of applying ICSO-ASV to design tree-type irrigation pipe networks. Thus, the design method proposed in this study can solve the optimal problems of tree-type irrigation pipe networks with varying topologies. The optimal solutions can be generated automatically using the ICSO-ASV algorithm if essential parameters of the pipe network planning model are provided.
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Martin-Du Pan, Oliver, Paul Woods e Richard Hanson-Graville. "Optimising pipe sizing and operating temperatures for district heating networks to minimise operational energy consumption". Building Services Engineering Research and Technology 40, n.º 2 (27 de setembro de 2018): 237–55. http://dx.doi.org/10.1177/0143624418802590.
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Reducing heat losses is an important factor in improving the performance of district heating networks. High heat losses are sometimes experienced in UK district heating networks and this is often as a result of poor design, partly due to oversized pipes. To provide additional guidance to designers on this issue, this paper proposes a set of maximum pipe diameters to be used for a given maximum flow rate to reduce the risk of oversizing and high heat losses. It was found that the optimised velocities are higher than those given in CIBSE CP1 Heat Networks Code of Practice and adopting these will result in smaller pipe diameters and lower operational and capital costs. The methodology used in this paper is based on minimising the total operational energy. The flow and return optimised pipe diameters are calculated for different scenarios which include variations in the pipe material, insulation thickness, water temperature and ambient environment. It was found that the optimised velocity in every scenario remains relatively constant with a varying pipe diameter. This paper shows that the operational cost of a DH network can be reduced when selecting the recommended maximum pipe diameter, compared to commonly used sizing criteria. Further savings can be achieved if the flow and return pipe are sized separately; to minimise operational energy of both flow and return pipes, the return pipe should be sized for a lower velocity. This paper also explores particular questions of interest: A range of insulation thicknesses. Benefit from using a variable flow temperature and to supply the flow at 90℃ at peak times instead of a constant temperature at 70℃. A comparison between steel and plastic pipes which have different roughness coefficients. Optimised differential pressure drop per unit length in both flow and return pipes. Maximum distance occurring before measuring a temperature loss and pressure drop of 1℃ and 1 bar, respectively, at peak load. However, this paper does not take into account any potential benefits that a lower flow temperature might have in reducing heat production costs or a lower return temperature might have in enhanced heat recovery, or that lower temperatures may enable use of plastic carrier pipes. Such matters are site specific but should be included in any similar pipe sizing analysis and operating temperature optimisation carried out for an actual scheme. Practical application: Optimising maximum pipe diameters is necessary to improve the viability of district heating systems. The current guidance for designers is not considered optimal and this paper suggests a new methodology to size pipes to reduce both the heat losses and the operational cost. This paper also gives guidance to sustainability engineers to assess the performance of 90/40℃, 70/40℃ and 60/30℃ district heating networks; 70℃ was assumed to be the minimum acceptable flow temperature in the network to enable domestic hot water to be heated to a safe temperature of 60℃ for storage; 40℃ was the used return temperature to be in line with the CIBSE Code of Practice CP1 stating in Objective 3.5 that best practice should achieve return temperatures below 40℃ for a scheme supplying heat to new buildings. A 90/40℃ DH network performance when increasing the flow temperature was then compared to the performance of a 70/40℃ system. Finally, a 60/30℃ system was also analysed to investigate the benefit from operating a DH network complying with the 4th generation of DH network temperatures that encourages minimal exergy destruction from the network to the end user.
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Giustolisi, O., e L. Berardi. "Water distribution network calibration using enhanced GGA and topological analysis". Journal of Hydroinformatics 13, n.º 4 (4 de outubro de 2010): 621–41. http://dx.doi.org/10.2166/hydro.2010.088.
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The calibration of hydraulic models of water distribution networks (WDN) is of preeminent importance for their analysis and management. It is usually achieved by solving a constrained optimization problem based on some priors on decision variables and the demand-driven simulation of the entire network, given the observations of some hydraulic status variables (i.e. typically nodal heads and sometimes pipe flows). This paper presents a framework to perform the calibration of pipe hydraulic resistances considering two main issues: (i) the enhancements of WDN simulation models allowing us to simplify network topology with respect to serial nodes/trunks and/or to account for a more realistic representation of distributed demands and (ii) a different formulation of the calibration problem itself. Depending on the available measurements, the proposed calibration strategy reduces the hydraulic simulation model size and can permit the decomposition of the network. On the one hand, such a procedure allows for numerical and computational advantages, especially for large size networks. On the other hand, it allows a prompt analysis of observability of calibration decision variables based on actual observations and might help identifying those pipes (i.e. hydraulic resistances) which are more important for the whole network behaviour.
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Vertommen, Ina, Karel van Laarhoven, Peter van Thienen, Claudia Agudelo-Vera, Tjakko Haaijer e Roel Diemel. "Optimal Design of and Transition towards Water Distribution Network Blueprints". Proceedings 2, n.º 11 (3 de agosto de 2018): 584. http://dx.doi.org/10.3390/proceedings2110584.
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The design of network blueprints (ideal design of water distribution networks taking into account the existing infrastructure) is optimized considering the minimization of costs while satisfying the required pressure and flow velocities. The optimal transition from the existing infrastructure towards the blueprint is described by the minimization of pipe failures or maximization of hydraulic performance and the number of construction sites, where old pipes are replaced by new ones, in each transition phase. Both problems are solved with Gondwana. An application to the network of Helmond-Mierlo (The Netherlands) shows that the costs for the optimized blueprint are only 64% of those from the currently existing infrastructure, while the hydraulic performance is improved. The optimized transition shows that a larger number of intervention sites allows for a higher reduction of pipe failures and a better hydraulic performance of the network.
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Neilands, K., M. Bernats e J. Rubulis. "Accumulation and modeling of particles in drinking water pipe fittings". Drinking Water Engineering and Science Discussions 5, n.º 1 (11 de abril de 2012): 139–71. http://dx.doi.org/10.5194/dwesd-5-139-2012.
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Abstract. The effect of pipe fittings – mainly T-pieces – on particle accumulation in drinking water distribution networks is shown in this work. The online measurements of flow and turbidity for cast iron, polyethylene and polyvinylchloride pipe sections have been linked with the analysis of pipe geometry. Up to 0.29 kg of the total mass of particles was found to be accumulated in T-pieces ranging from DN 100/100–DN 250/250. The accumulated amount of particles in the fittings was defined as J and introduced into the existing turbidity model PODDS (Prediction of Discolouration in Distribution Systems) proposed by Boxall et al. (2001), which describes the erosion of particles leading to discoloration events in drinking water networks, viz. sections, of straight pipes. It does not interpret the mobilization of particles in pipe fittings, however, which have been considered in this article. T-pieces were the object of this study and depending on the diameter or daily flow velocity, the coefficient J varied from 1.16 to 8.02.
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Menaia, J., S. T. Coelho, A. Lopes, E. Fonte e J. Palma. "Dependency of bulk chlorine decay rates on flow velocity in water distribution networks". Water Supply 3, n.º 1-2 (1 de março de 2003): 209–14. http://dx.doi.org/10.2166/ws.2003.0105.
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Understanding chlorine residual decay kinetics and the factors that influence them are essential for such current tasks as siting chlorination facilities, dosage optimisation, choice of sampling locations and frequencies, and general design and operational control of drinking water networks, increasingly accomplished with the help of simulation models. Available constants for bulk chlorine decay are typically determined under static conditions. However, as for all fast reactions in water flows, chlorine consumption rates in drinking water pipes may be influenced by the existing mixing regimes, a function of flow turbulence, which is primarily controlled by flow velocity and pipe diameter. Flow velocities vary greatly in space and time in water transmission and distribution systems; pipe diameters are seldom uniform. Although both variables are readily available in the currently available network analysis simulators that implement chlorine models, such variations are not accounted for. Instead, a single preset decay rate constant is generally used for describing chlorine residual consumption throughout an entire system. In addition to highlighting how negligible PVC pipe wall chlorine consumption is, as such, this paper presents experimental evidence of a significant correlation between pipe flow velocity and bulk chlorine decay rates, and proposes a simple but effective approach to implement this dependency in current simulators.
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Gönczi, Gábor. "Computational fluid dynamics aided optimisation of liquid state antiseptic injection to water networks". Water Practice and Technology 9, n.º 3 (1 de setembro de 2014): 362–69. http://dx.doi.org/10.2166/wpt.2014.038.
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Waterworks mostly use chlorine as an antiseptic substance. It can be added in gaseous or liquid form. The simplest technique is to use gaseous injection but it carries the most risk as chlorine gas is highly toxic. Therefore, the current trend is to switch to the much safer hypo doser technology, whereby the hypo is injected into the water pipes with injector tubes, similarly to chlorination but the mixing of the antiseptic liquid is more problematic. Correct placement of the inlet and measurement points is indispensable. With the help of the computational fluid dynamic (CFD) simulation not only can the flow of the specific water pipe be modelled but also mixing of the antiseptic fluid can be modelled, thereby the measurement and inlet points can be installed at the optimal locations. In very short pipe sections with a limited amount of pipe length to achieve proper mixing the use of static mixers was suggested. Efficiency of the static mixers is variable and they increase the pressure loss on the specific water pipe section, which inflicts additional energy costs. With the help of CFD modelling, the fluid dynamic phenomena (vortices, backflows, etc.) on these pipe sections can be utilised to help mixing of the antiseptic substance meaning the use of static mixers can be avoided.
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Motiee, Homayoun, e Sonya Ghasemnejad. "Prediction of pipe failure rate in Tehran water distribution networks by applying regression models". Water Supply 19, n.º 3 (26 de julho de 2018): 695–702. http://dx.doi.org/10.2166/ws.2018.137.
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Abstract Four statistical models (linear regression, exponential regression, Poisson regression and logistic regression) applied to analyze the variables in pipe vulnerabilities with the objective of finding equations to predict probable future pipe accidents. The most effective variables in pipe failures are material, age, length, diameter and hydraulic pressure. To evaluate these models, the data collected in recent years in the water distribution network of district 1 in Tehran were used, with a total length of 582,702 m of pipes, and 48,500 consumers. The results demonstrate that among the four studied models, the logistic regression model is best able to give a good performance and is capable of predicting future accidents with a higher probability.
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Jha, Kailash, e Manish Kumar Mishra. "Object-oriented integrated algorithms for efficient water pipe network by modified Hardy Cross technique". Journal of Computational Design and Engineering 7, n.º 1 (1 de fevereiro de 2020): 56–64. http://dx.doi.org/10.1093/jcde/qwaa006.
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Abstract In this work, object-oriented integrated algorithms for an efficient flow analysis of the water pipe network are developed. This is achieved by treating the pipe network as a graph data structure with its nodes as the graph’s nodes and the pipes as the edges. The algorithm for cycle (real cycle or pseudo-cycle) extraction has been developed using nested breadth-first search that gives ordered cycles. Pseudo-loops are found using the shortest path algorithm between the nodes. Pipes are initialized loop by loop using conservation of mass at nodes. A modified Hardy Cross method is used in the proposed work with third-order convergence. The friction factor is updated for every change in discharges. The pressure calculation has been done by the graph traversal algorithm between the reference nodes and node where the pressure is to be calculated using the energy equation. The pressure at all intermediate nodes is obtained in the course of the traversal. Balanced discharges and nodal pressure in the pipe network are compared with the simultaneous loop flow adjustment method and EPANET software. The proposed work gives more efficient flow analysis than the traditional Newton–Raphson-based techniques for complex networks.
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Ghobadi, Fatemeh, Gimoon Jeong e Doosun Kang. "Water Pipe Replacement Scheduling Based on Life Cycle Cost Assessment and Optimization Algorithm". Water 13, n.º 5 (25 de fevereiro de 2021): 605. http://dx.doi.org/10.3390/w13050605.
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Water distribution networks (WDNs) comprise a complex network of pipes and are crucial for providing potable water to urban communities. Therefore, WDNs must be carefully managed to avoid problems such as water contamination and service failures; however, this requires a large budget. Because WDN components have different statuses depending on their installation year, location, transmission pressure, and flow rate, it is difficult to plan the rehabilitation schedule within budgetary constraints. This study, therefore, proposes a new pipe replacement scheduling approach to smooth the investment time series based on a life cycle cost (LCC) assessment for a large-scale WDN. The proposed scheduling plan simultaneously considers both the annual budget limitation and the optimum expenditure on the useful life of pipes. A multi-objective optimization problem consisting of three decision-making objectives—minimum imposed LCC on the network, minimum standard deviation of annual investment, and minimum average age of the network—is thus solved using a nondominated sorting genetic algorithm to obtain an optimal plan. Three scenarios with different pipe replacement time spans and different annual budget constraints are considered accordingly. The results indicate that the proposed scheduling framework provides an efficient water pipe replacement scheduling plan with a smooth management budget.
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Lee, Jinwoo, Gunhui Chung, Heeseong Park e Innjoon Park. "Evaluation of the Structure of Urban Stormwater Pipe Network Using Drainage Density". Water 10, n.º 10 (13 de outubro de 2018): 1444. http://dx.doi.org/10.3390/w10101444.
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In mega cities such as Seoul in South Korea, it is very important to protect the cities from surface flooding even for a short time period due to the enormous economic damage. That is why stormwater pipe networks are commonly applied to mega cities with large impervious areas to drain runoff from the city. Therefore, the stormwater pipe networks in urban catchments should be carefully designed for quick and efficient runoff removal. In this study, the structures of different stormwater pipe networks were evaluated based on the relationship between peak rainfall and runoff in the urban catchments in South Korea. More than 400 historical rainfall events from five urban catchments were used to develop respective linear regression models for estimating peak runoff for different pipe network structures. The developed regression models exhibited greater than 0.9 in determination coefficients and demonstrated overall the broader ranges in peak runoff with the greater rainfall amount, especially when the pipe networks were branched. This implies that the effect of pipe network structures on runoff is more profound in the branched networks whose runoff water flow is one-directional and thus tends to concentrate to the catchment outlet. In the case of the looped networks in which runoff paths are multiple, rainfall runoff can be routed to several alternative water paths depending on rainfall events resulting in the reduced peak runoff. The structures of pipe networks can be measured in drainage density which is defined as the ratio of total pipe length to catchment area. As a result, the range of the estimated runoff at the 95% confidence level increased as the drainage density increased, which implies increased uncertainty with the looped networks which commonly involve more pipe installation for unit area as compared to the branched. However, the looped networks with multiple water paths can reduce the time to drain rainfall from the catchments and thus the 95% confidence interval becomes narrow, which means greater reliability in peak runoff estimation. It would therefore be favorable to adopt looped stormwater pipe networks within an affordable budget and the complexity of pipe networks needs to be counted to reduce urban flood risk.
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Palod, Nikita, Vishnu Prasad e Ruchi Khare. "Non-parametric optimization technique for water distribution in pipe networks". Water Supply 20, n.º 8 (25 de agosto de 2020): 3068–82. http://dx.doi.org/10.2166/ws.2020.200.
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Abstract Water distribution networks (WDN) contribute the massive cost of pipes in total water distribution system (WDS) design, thus the optimal design of any WDN is more of a necessity than a requirement. Various evolutionary algorithms (EAs) proposed in the past involve the use of algorithm-specific parameters and their synchronizing to get the optimal solution and thus require more computational effort and time. To overcome this drawback, the present work introduces an optimization technique, JayaNet, which is the integration of the Jaya algorithm and hydraulic network solver EPANET 2. The best part of this technique is that no algorithm-specific parameter is to be synchronized for optimal cost but there needs to be adjustment of penalty parameter and population size based on network size. Four well-known benchmark networks with different sizes and layout have been taken and optimized using JayaNet. The results are compared with those obtained from other EAs. It is found that optimized costs obtained for four networks by JayaNet are either the same or less than the results obtained from other EAs even with a lower number of function evaluations (NFE). The NFE are found to increase with population size in all networks. The statistical parameter obtained from JayaNet is also compared for different networks.
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Shrivastava, V., A. Jaiswal, P. K. Thakur, S. P. Agarwal, P. Kumar, G. K. Kota, D. Carrera, M. K. Dhasmana, V. Sharma e S. Singh. "APPLICATION OF GIS FOR THE DESIGN OF POTABLE WATER DISTRIBUTION SYSTEM IN IIRS". ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences IV-5 (15 de novembro de 2018): 87–94. http://dx.doi.org/10.5194/isprs-annals-iv-5-87-2018.
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<p><strong>Abstract.</strong> The design and analysis of potable water distribution pipe network is one of the major task while planning any new city. Even finding the effectiveness and detecting any anomaly in the existing pipe line network is a very important to cut down losses and make a network all time efficient. This study makes an attempt to evaluate the existing water distribution network of Indian Institute of Remote Sensing (IIRS) and new pipe network to be developed under the master plan 2022. The new development induces an extra demand of 67634 litres per day (lpd). The Digital Globe image from Google Earth Pro is used for creating base layer and campus layout. ALOS PALSAR digital elevation model (DEM) is used to get elevation of nodes and tanks, which helps in alignment of pipes. Field survey was done for finding all the data necessary to make the database for input for EPANET 2.0. EPANET 2.0 pipe hydraulic model was used to test and design the existing and proposed potable water distribution pipe network. The results of evaluation of current operations show that the system can be made capable to fulfil the demand by increasing pumping time. But the future network operation requires an increase in pumping capability of 71 litre per minute (lpm) for filling Overhead tank. This study proves that geospatial technology is an efficient, time and cost saving alternative to the traditional methods of design and evaluation of potable water distribution networks.</p>
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Feng, Cuimin, Na Zhu, Ying Li, Zhen Xu e Ziyu Guo. "Microbial Characteristics of the Combined Ozone and Tea Polyphenols or Sodium Hypochlorite Disinfection in the Pipe Network". Water 13, n.º 13 (30 de junho de 2021): 1835. http://dx.doi.org/10.3390/w13131835.
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Microbiological safety of water in the pipe network is an important guarantee for safe drinking water. Simulation tests of stainless steel pipe network were carried out using te4a polyphenols and sodium hypochlorite as auxiliary disinfectants for ozone disinfection to analyze the persistent disinfection effects of different combined disinfection methods by measuring the changes in total bacterial colonies in the water. High-throughput sequencing of microorganisms in the pipe network was performed to analyze the differences in the community structure of microorganisms in the water and pipe wall under different disinfection methods. The results showed that the application of auxiliary disinfectants had a relatively long-lasting inhibitory effect on the bacterial colonies in the water, and the diversity of microorganisms in the pipe network varied significantly. As an auxiliary disinfectant for ozone disinfection, tea polyphenols are more powerful than sodium hypochlorite in killing pathogens and chlorine-resistant bacteria, so they are more beneficial to ensure the microbiological safety of water in stainless steel pipe networks.
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Laakso, Tuija, Suvi Ahopelto, Tiia Lampola, Teemu Kokkonen e Riku Vahala. "Estimating water and wastewater pipe failure consequences and the most detrimental failure modes". Water Supply 18, n.º 3 (14 de agosto de 2017): 901–9. http://dx.doi.org/10.2166/ws.2017.164.
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Abstract Failures of water and wastewater networks can lead to severe consequences for the human, natural and built environments. This paper presents how data on networks and their immediate environment together with graph analysis can be used to estimate the severity of pipe failure consequences. A case study concerning a large water and wastewater utility revealed that ca. 14% of the water distribution pipes and ca. 25% of the sewers had potentially severe failure consequences with regard to at least one factor considered. The most detrimental failure modes connected to these pipes were identified. An assessment of the most important information needs revealed that a number of crucial source data sets were missing. The results can be used to support asset management decisions aiming at risk alleviation, e.g. when estimating the resources needed for network maintenance, condition inspections or renovations and when planning excavation works.
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Campisano, Alberto, e Enrico Creaco. "Advances in Modeling and Management of Urban Water Networks". Water 12, n.º 11 (22 de outubro de 2020): 2956. http://dx.doi.org/10.3390/w12112956.
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This Editorial presents a representative collection of 15 papers, presented in the Special Issue on Advances in Modeling and Management of Urban Water Networks (UWNs), and frames them in the current research trends. The most analyzed systems in the Special Issue are the Water Distribution Systems (WDSs), with the following four topics explored: asset management, modelling of demand and hydraulics, energy recovery, and pipe burst identification and leakage reduction. In the first topic, the multi-objective optimization of interventions on the network is presented to find trade-off solutions between costs and efficiency. In the second topic, methodologies are presented to simulate and predict demand and to simulate network behavior in emergency scenarios. In the third topic, a methodology is presented for the multi-objective optimization of pump-as-turbine (PAT) installation sites in transmission mains. In the fourth topic, methodologies for pipe burst identification and leakage reduction are presented. As for the Urban Drainage Systems (UDSs), the two explored topics are asset management, with a system upgrade to reduce flooding, and modelling of flow and water quality, with analyses on the transition from surface to pressurized flow, impact of water use reduction on the operation of UDSs and sediment transport in pressurized pipes. The Special Issue also includes one paper dealing with the hydraulic modelling of an urban river with a complex cross-section.
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Kim, J. H., C. W. Baek, D. J. Jo, E. S. Kim e M. J. Park. "Optimal planning model for rehabilitation of water networks". Water Supply 4, n.º 3 (1 de junho de 2004): 133–48. http://dx.doi.org/10.2166/ws.2004.0050.
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An optimal planning model for rehabilitation of water networks is presented. Capital costs (replacement, rehabilitation and repairing costs), benefits (by the reduction of pumping cost and leakage cost), and hydraulic reliability are used for making an optimal decision for the rehabilitation plan of a water pipe network. KYPIPE is used for checking the hydraulic reliability. A multi-objective optimization model is successfully developed in this study. And the task is tackled using a new meta-heuristic algorithm, Harmony Search, for solving a large optimization problem to which conventional optimization techniques are poorly suited. Five different models with different objective functions are developed and tested according to various conditions considered in this study. These models provide more options for the rehabilitation of pipe network systems compared to previously suggested models in the literature.
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Robles-Velasco, Alicia, Cristóbal Ramos-Salgado, Jesús Muñuzuri e Pablo Cortés. "Artificial Neural Networks to Forecast Failures in Water Supply Pipes". Sustainability 13, n.º 15 (23 de julho de 2021): 8226. http://dx.doi.org/10.3390/su13158226.
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The water supply networks of many countries are experiencing a drastic increase in the number of pipe failures. To reverse this tendency, it is essential to optimise the replacement plans of pipes. For this reason, companies demand pioneering techniques to predict which pipes are more prone to fail. In this study, an Artificial Neural Network (ANN) is designed to classify pipes according to their predisposition to fail based on physical and operational input variables. In addition, the usefulness and effectiveness of two sampling methods, under-sampling and over-sampling, are analysed. The implementation of the model is done using the open-source software Weka, which is specialised in machine-learning algorithms. The system is tested with a database from a real water network in Spain, obtaining high-accurate results. It is verified that the balance of the training set is imperative to increase the predictions’ accurateness. Furthermore, under-sampling prioritises true positive rates, whereas over-sampling makes the system learn to predict failures and non-failures with the same precision.
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Chowdhury, R. K., e M. A. Rajput. "Will greywater reuse really affect the sewer flow? Experience of a residential complex in Al Ain, UAE". Water Supply 17, n.º 1 (10 de agosto de 2016): 246–58. http://dx.doi.org/10.2166/ws.2016.131.
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Reuse of recycled wastewater is one of the most feasible unconventional urban water sources in the United Arab Emirates (UAE). The extraction and reuse of greywater might affect the water and sewer pipe networks by changing flow characteristics. Therefore, the research question is how much greywater can be reused without affecting the existing water and sewer pipe networks? A residential complex located in Al Ain, UAE, was investigated in this regard. Water pipe network, water consumption and sewer flow data were collected and scenario modelling was conducted using the EPANET software. It was found that 100% capture and reuse of greywater has no impact on the upstream water distribution network, but reduces the recommended design flow in the downstream sewer network. The modelling results show that about 50% of generated greywater (about 95 litres per capita per day) can be harvested without affecting the upstream and downstream water and sewer flow characteristics, respectively.
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Barton, Neal Andrew, Timothy Stephen Farewell, Stephen Henry Hallett e Timothy Francis Acland. "Improving pipe failure predictions: Factors affecting pipe failure in drinking water networks". Water Research 164 (novembro de 2019): 114926. http://dx.doi.org/10.1016/j.watres.2019.114926.
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Ho, Clifford K. "Solute Mixing Models for Water-Distribution Pipe Networks". Journal of Hydraulic Engineering 134, n.º 9 (setembro de 2008): 1236–44. http://dx.doi.org/10.1061/(asce)0733-9429(2008)134:9(1236).
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Sarbu, Ioan, e Gabriel Ostafe. "Optimal design of urban water supply pipe networks". Urban Water Journal 13, n.º 5 (15 de janeiro de 2015): 521–35. http://dx.doi.org/10.1080/1573062x.2014.994007.
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Jowitt, P. W., e Chengchao Xu. "Predicting Pipe Failure Effects in Water Distribution Networks". Journal of Water Resources Planning and Management 119, n.º 1 (janeiro de 1993): 18–31. http://dx.doi.org/10.1061/(asce)0733-9496(1993)119:1(18).
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