Extending EPANET capabilities with Add-In Tools

[EN] EPANET is probably the most widespread model for water distribution network (WDN). More than twenty years after its appearance, it has become a global reference both for hydraulic and quality analysis of water networks. In 2000, EPANET 2 appears, which includes as most important computational feature a new Toolkit. This toolkit was a library of functions allowing the modification of network data and reading results without access to the appropriate files. Over time, the use of this library has been the communication protocol for every application developers who use the method propose by Todini and Pilati to analyze the behavior of WDN. This library also provides interface tools that allow the execution of a simulation from an external application, as long as the network characteristics had been previously defined. This paper presents a change in the original EPANET model, including a new menu in the graphical user interface (GUI). This menu allows users to set up a personal collection of Add-In tools, which use both project data and simulation results. These tools can be customized and allows to extend the analysis capability of EPANET. All of them can access EPANET functions through the Toolkit and were developed by the authors during the Spanish translation of EPANET, taking into account the homologous Add-in tools developed for SWMM model. As an example of the operation and capabilities of this new menu, several applications integrated as EPANET add-in tools are presented. These tools perform tasks such as importing data network from both CAD and GIS systems, the design of WDNs using genetic algorithms, automatic assignment of initial water quality to network nodes; the skeletonization of a network or optimization of pumping schedule in the network in order to achieve a minimum energy cost.Iglesias Rey, PL.; Martínez-Solano, FJ.; Ribelles-Aguilar, J. (2017). Extending EPANET capabilities with Add-In Tools. Procedia Engineering. 186:626-634. doi:10.1016/j.proeng.2017.03.279S62663418

BBLAWN: A combined use of best management practices and an optimization model based on a pseudo-genetic algorithm

[EN] The paper presents a solution to the problem of the Battle of Background Leakage Assessment for Water Networks (BBLAWN) using a methodology that combines the use of Best Management Practices (BMPs) and an optimization model based on a Pseudo- Genetic Algorithm (PGA) as described in [1]. In a first stage, an analysis of marginal costs of pipes whose replacement would be potentially recommended was performed. Next, a network topological analysis to study the pipes that could potentially be closed in order to facilitate pressure control was done. Furthermore, a methodology for studying branched areas was also developed, determining possible location for pressure reducing valves (PRV). A significant reduction in the number of decision variables was obtained and a specific optimization model was developed.This work was supported by the project DPI2009-13674 (OPERAGUA) of the Dirección General de Investigación y Gestión del Plan Nacional de I + D + I del Ministerio de Ciencia e Innovación, Spain.Iglesias Rey, PL.; Martínez-Solano, FJ.; Mora Melia, D.; Martinez Solano, PD. (2014). BBLAWN: A combined use of best management practices and an optimization model based on a pseudo-genetic algorithm. Procedia Engineering. 89:29-36. doi:10.1016/j.proeng.2014.11.156S29368

Efficiency of evolutionary algorithms in water network pipe sizing

© 2015, Springer Science+Business Media Dordrecht. The pipe sizing of water networks via evolutionary algorithms is of great interest because it allows the selection of alternative economical solutions that meet a set of design requirements. However, available evolutionary methods are numerous, and methodologies to compare the performance of these methods beyond obtaining a minimal solution for a given problem are currently lacking. A methodology to compare algorithms based on an efficiency rate (E) is presented here and applied to the pipe-sizing problem of four medium-sized benchmark networks (Hanoi, New York Tunnel, GoYang and R-9 Joao Pessoa). E numerically determines the performance of a given algorithm while also considering the quality of the obtained solution and the required computational effort. From the wide range of available evolutionary algorithms, four algorithms were selected to implement the methodology: a PseudoGenetic Algorithm (PGA), Particle Swarm Optimization (PSO), a Harmony Search and a modified Shuffled Frog Leaping Algorithm (SFLA). After more than 500,000 simulations, a statistical analysis was performed based on the specific parameters each algorithm requires to operate, and finally, E was analyzed for each network and algorithm. The efficiency measure indicated that PGA is the most efficient algorithm for problems of greater complexity and that HS is the most efficient algorithm for less complex problems. However, the main contribution of this work is that the proposed efficiency ratio provides a neutral strategy to compare optimization algorithms and may be useful in the future to select the most appropriate algorithm for different types of optimization problems

Sensitivity parameters during the emptying maneuvers in water pipelines

[EN] Emptying pipelines can be critical in many water pipelines because subatmospheric pressure troughs are reached due to the expansion of entrapped air, which could cause considerable damage to the system depending on both installation conditions and stiffness pipe. This paper shows the sensitivity analysis for the mathematical model proposed by the authors, where the main hydraulic and thermodynamic parameters are analyzed (internal pipe diameter, friction factor, pipe slope, polytropic coefficient, air valve diameter, air pocket size and time maneuvering of the drain valve). Two cases were analyzed: (i) a pipe with the upstream end closed, and (ii) a pipe with an air valve installed in the upstream end. The results show that in the Case No.1, pipe slope, polytropic coefficient and air pocket size parameters are very sensitive on the subatmospheric pressure troughs, and on the other hand in the Case No. 2, the majority of parameters are very sensitive during the emptying process.[ES] El proceso de vaciado en conducciones de agua genera depresiones por la expansión del aire en el interior de las tuberías y esto podría causar el colapso del sistema dependiendo de las condiciones de instalación y de la rigidez de la conducción. En este artículo se presenta el análisis de sensibilidad del modelo matemático desarrollado por los autores, analizando los principales parámetros hidráulicos y termodinámicos que intervienen en este proceso tales como: diámetro interior de la tubería, factor de fricción, pendiente longitudinal de la tubería, coeficiente politrópico, diámetro de la ventosa, tamaño de la bolsa de aire y tiempo de apertura. Este análisis se realizó para dos casos posibles: Caso No. 1, tubería con el extremo aguas arriba cerrado; y Caso No. 2, tubería con una ventosa instalada en el extremo aguas arriba. Los resultados muestran que para el Caso No. 1 los parámetros que más inciden en las depresiones son la pendiente longitudinal de la tubería, el coeficiente politrópico y el tamaño de la bolsa de aire; mientras que para el Caso No. 2, la mayoría de los parámetros influyen significativamente durante el proceso de vaciado.Los autores agradecen la financiación del estudiante de doctorado Óscar E. Coronado-Hernández, realizada por la Fundación Centro de Estudios Interdisciplinarios Básicos y Aplicados (CEIBA) - Gobernación de Bolívar (Colombia).Coronado-Hernández, O.; Fuertes-Miquel, V.; Iglesias-Rey, P.; Mora-Meliá, D. (2018). Parámetros significativos durante los procesos de vaciado en conducciones de agua. Ingeniería del Agua. 22(3):141-152. https://doi.org/10.4995/ia.2018.9292SWORD141152223AWWA. American Water Works Association. Manual of water supply practices M51: air release, air-vacuum, and combination air valves. Denver, USA, 2001.Coronado-Hernández, O.E., Fuertes-Miquel, V.S., Besharat, M., Ramos, H.M. 2017. Experimental and numerical analysis of a water emptying pipeline using different air valves. Water , 9(2), 98. doi:10.3390/w9020098.Coronado-Hernández, O.E., Fuertes-Miquel, V.S., Angulo-Hernández, F.N. 2017. Emptying Operation of Water Supply Networks. Water , 10(1), 22. doi: 10.3390/w10010022.Coronado-Hernández, O.E., Fuertes-Miquel, V.S., Iglesias-Rey, P.L., Martínez-Solano, F.J. 2018. Rigid Water Column Model for Simulating the Emptying Process in a Pipeline Using Pressurized Air. Journal of Hydraulic Engineering (Aceptado). doi: 10.1061/(ASCE)HY.1943-7900.0001446.Coronado-Hernández, O.E., Fuertes-Miquel, V.S., Iglesias-Rey, P.L., Mora-Meliá, D. 2016. Análisis de los fenómenos transitorios generados durante el vaciado de agua en una tubería simple. IAHR - XXVII Congreso Latinoamericano de Hidráulica. Septiembre 28-30. Lima, Perú.Fuertes-Miquel, V.S., Coronado-Hernández, O.E., Iglesias-Rey, P.L., Mora-Meliá, D. 2017. Transient phenomenon during the emptying process of a single pipe with water-air interaction. Journal of Hydraulic Research (pendiente de publicación).Fuertes-Miquel, V. S., López-Jiménez, P. A., Martínez-Solano, F. J., López-Patiño, G. 2016. Numerical modelling of pipelines with air pockets and air valves. Canadian. Journal of Civil Engineering, 43(12):1052-1061.Fuertes-Miquel, V.S. 2001. Hydraulic transients with entrapped air pockets. Ph.D. Thesis, Department of Hydraulic Engineering, Polytechnic University of Valencia, Valencia, Spain.Izquierdo, J., Fuertes, V.S., Cabrera, E., Iglesias, P., García-Serra, J. 1999. Pipeline start-up with entrapped air. Journal of Hydraulic Research, 37, 579-590. doi: 10.1080/00221689909498518.Laanearu, J., Annus, I., Koppel, T., Bergant, A., Vučkovic', S., Hou, Q., Tijsseling, A.S., Anderson, A., Van't Westende, J.M.C. 2012. Emptying of Large-Scale Pipeline by Pressurized Air, Journal of Hydraulic Engineering (138), 1090-1100. doi:10.1061/(ASCE)HY.1943-7900.0000631.León, A., Ghidaoui, M., Schmidt, A., Garcia, M. 2010. A robust two-equation model for transient-mixed flows. Journal of Hydraulic Research, 48, 44-56, http://dx.doi.org/10.1080/00221680903565911.Liou, C., Hunt, W.A. 1996. Filling of Pipelines with Undulating Elevation Profiles. Journal of Hydraulic Engineering 122, 534-539. doi:10.1061/(ASCE)0733-9429(1996)122:10(534).Martins, S.C., Ramos, H.M., Almeida, A.B. 2015. Conceptual analogy for modelling entrapped air action in hydraulic systems. Journal of Hydraulic Research. pp 678-686.Martino, G., Fontana, N., Giugni, M. 2008. Transient flow caused by air expulsion through an orifice. Journal of Hydraulic Engineering, 134(9):1395-1399. doi:10.1061/(ASCE)0733-9429(2008)134:9(1395).Ramezani, L., Karney, B., Malekpour, B.A. 2015. The Challenge of Air Valves: A Selective Critical Literature Review. Journal of Water Resources and Planning Management, doi:10.1061/(ASCE)WR.1943-5452.0000530.Ramezani, L., Karney, B., Malekpour, A. 2016. Encouraging Effective Air Management in Water Pipelines: A Critical Review. Journal of Water Resources Planning and Management 142 (12). doi: 10.1061/(ASCE)WR.1943-5452.0000695.Wang, L., Wang, F., Karney, B., Malekpour, A. 2017. Numerical investigation of rapid filling in bypass pipelines. Journal of Hydraulic Research, 55(5), 647-656. doi:10.1080/00221686.2017.1300193.Wylie, E., Streeter, V. 1993. Fluid transients in systems; Prentice Hall: Englewood Cliffs, NJ, USA.Zhou, L., Liu, D. 2013. Experimental investigation of entrapped air pocket in a partially full water pipe. Journal of Hydraulic Research, 51, 469-474, http://dx.doi.org/10.1080/00221686.2013.785985.Zhou, L., Liu, D., Karney, B. 2013. Investigation of Hydraulic Transients of Two Entrapped Air Pockets in a Water Pipeline. Journal of Hydraulic Engineering 139, 949-959. doi:10.1061/(ASCE)HY.1943-7900.0000750

Characterization of modular deposits for urban drainage networks using CFD techniques

[EN] The growing urban development of population centers in much of the world joined with the significant effects of climate change are causing an increasingly important and recurring increase of the damage caused by flooding. Much of the drainage networks of cities were designed for precipitation characteristics and return periods that have proved to be insufficient with the lapse of time. Therefore, solutions need to be addressed both to reduce runoff generated flows as to control circulating ones through the rainwater drainage networks. All these flow control rain technologies are commonly known as SUDS (Sustainable Urban Drainage), term that encompasses a multitude of solutions to control runoff although many of them require significant costs that make them practically unviable. Therefore, not only should focus on reducing runoff input to the network but also in the flow control techniques development. The idea is to design strategies to reduce flow rain peaks and maximize the capacity of existing networks. The use of detention and storm tanks for flood control is a solution increasingly used as an alternative one to control increased rainfall caused by climate change [1]. Nature and execution of storm tanks can be very diverse, from conventional way based on concrete structures to the most innovative ones in which modular structures are employed to improve the construction speed if many modular units are required at the same time that minimizing urban supply disruption is achieved. Currently, a wide range of modular structures exists on the market with both, different geometries and sizes. In this study the Aquacell brand supplied by Mexichem-PAVCO in Colombia shown in Fig. 1 has been chosen for the development of this study.S849218

Energy optimization of supplied flows from multiple pumping stations in water distributions networks

[EN] One of the most important concerns within the field of urban hydraulic engineers is the right management of water resources. When there is more than one water source, there is a question that must be answered: How much water should be provided by each water source according to the demand curve of the network? This work proposes a methodology that solves this question. It involves an energy analysis of the water network based on the concept of the setpoint curve. The setpoint curve gives, for every supplied flow, the minimum head needed to satisfy pressure requirements in the network. In this sense, the setpoint curve of every source relates two variables: supplied flow and minimum required head. Energy consumption in every source is evaluated by means of the product of these two variables. Then flow distribution among sources is optimized and minimum heads are obtained from the setpoint curve. The optimization process has been validated in two different ways. On one hand, a discrete method has been used, where a predefined combination of flow distributions are evaluated. On the other hand, the solution is found by means of Hooke-Jeeves and Nelder-Mead optimization algorithms. To apply these methods EPANET and its Toolkit has been applied to the mathematical model of the network. The optimization process can be applied to networks models with and without leakages. Finally, the methodology is applied to two cases, one academic network and real network where maximum flow limitations of every source were also taken into account.León Celi, CF.; Iglesias Rey, PL.; Martínez-Solano, FJ. (2017). Energy optimization of supplied flows from multiple pumping stations in water distributions networks. Procedia Engineering. 186:93-100. doi:10.1016/j.proeng.2017.03.214S9310018

Effects of orifice sizes for uncontrolled filling processes in water pipelines

The sizing of air valves during the air expulsion phase in rapid filling processes is crucial for design purposes. Mathematical models have been developed to simulate the behaviour of air valves during filling processes for air expulsion, utilising 1D and 2D schemes. These transient events involve the presence of two fluids with different properties and behaviours (water and air). The effect of air valves under scenarios of controlled filling processes has been studied by various authors; however, the analysis of uncontrolled filling processes using air valves has not yet been considered. In this scenario, water columns reach high velocities, causing part of them to close air valves, which generates an additional peak in air pocket pressure patterns. In this research, a two-dimensional computational fluid dynamics model is developed in OpenFOAM software to simulate the studied situations

Using the set point concept to allow water distribution system skeletonization preserving water quality constraints

[EN] Water distribution networks were included in the catalogue of critical infrastructures by different institutions as the European Council. One of the vulnerabilities of a water distribution networks consists of the contamination due to accidental or provoked events. Therefore, it is increasingly common to develop water quality models which allow the study of these threats. Many hydraulic models use algorithms with a high computational cost. Therefore, any strategy to accelerate these algorithms is an important contribution to the problem. This paper proposes a method to simplify branched areas of the network without losing information regarding water quality.This article has been possible inside the actions developed by the researchers of UPV involved in the project “Mejora de las técnicas de llenado y operación de redes de abastecimiento de agua (OPERAGUA)”. The number reference of the project is DPI2009-13674.Martínez-Solano, FJ.; Iglesias Rey, PL.; Mora Meliá, D.; Fuertes Miquel, VS. (2014). Using the set point concept to allow water distribution system skeletonization preserving water quality constraints. Procedia Engineering. 2014(89):213-219. https://doi.org/10.1016/j.proeng.2014.11.179S21321920148

Drinking water temperature around the globe : understanding, policies, challenges and opportunities

Water temperature is often monitored at water sources and treatment works; however, there is limited monitoring of the water temperature in the drinking water distribution system (DWDS), despite a known impact on physical, chemical and microbial reactions which impact water quality. A key parameter influencing drinking water temperature is soil temperature, which is influenced by the urban heat island effects. This paper provides critique and comprehensive summary of the current knowledge, policies and challenges regarding drinking water temperature research and presents the findings from a survey of international stakeholders. Knowledge gaps as well as challenges and opportunities for monitoring and research are identified. The conclusion of the study is that temperature in the DWDS is an emerging concern in various countries regardless of the water source and treatment, climate conditions, or network characteristics such as topology, pipe material or diameter. More research is needed, especially to determine (i) the effect of higher temperatures, (ii) a legislative limit on temperature and (iii) measures to comply with this limit