Practical Application Of Pressure-Dependent EPANET Extension

Hydraulic models have been widely used in the design and operation of water distribution system (WDSs). The models enable planning for possible changes in the system under a wide range of conditions. Under abnormal operating condition, for instance, WDSs become pressure deficient and unable to satisfy demand fully. In such circumstances, pressure dependent models are suitable to quantify the shortfall in flow and pressure accurately for crucial decision-making. Most recently, a pressure dependent extension of the renowned EPANET hydraulic simulator was developed to enable modelling of pressure deficient networks. The model has an integrated pressure dependent demand (i.e. nodal flow) function coupled with a line search and backtracking procedure to facilitate convergence. Extensive verifications were conducted on the model using benchmark and real life networks and good modelling performances were accomplished. The model was combined with multi-objective genetic algorithm for optimisation of design, rehabilitation and operation of WDSs. It generated superior results for benchmark as well as real life networks in terms of cost, hydraulic performance and computational time in reference to previous solutions. It has also been utilised for water quality modelling of real life networks. Overall, the model has not experienced convergence problems when executing the various simulations. Having demonstrated the robustness and benefits of the model previously including seamless integration in genetic algorithms, it would be greatly beneficial on investigating ways of improving the algorithm further. In this work, the line search and backtracking procedure of the algorithm has been improved. This has improved the robustness further by enhancing greatly the computational properties for low flow conditions and increasing the algorithm’s consistency over a wider range of operating conditions. Extended period simulations were executed on real life network considering source head variations and pipe closure conditions

Constraint programming for optimal design of architectures for water distribution tanks and reservoirs: a case study

Sustav za raspodjelu vode je bitna komponenta svakog gradskog infrastrukturnog sustava. Njegov je projekt uglavnom težak zadatak zbog postojanja nekoliko složenih međusobno povezanih parametara. Između ostalih, neki parametri koji se moraju proučiti su potražnja za vodom, potrebni tlak, topografija, lokacija resursa, pouzdanost sustava, i korištenje energije. U ovom smo radu usmjereni na postojeći slučaj sustava za distribuciju vode s ciljem smanjenja troškova instaliranja zadovoljavanjem zahtjeva toga sustava. Problem rješavamo primjenom najnovijih metoda Programiranja Ograničenja kombiniranih s Analizom Intervala u svrhu preciznog baratanja s trajnim varijablama odluka. Eksperimentalni rezultati pokazuju da je predloženi pristup izvediv i globalni optimum postignut u svim slučajevima i u zadovoljavajućem vremenu.A water distribution system is an essential component of any urban infrastructure system. Its design is commonly a hard task mainly due to the presence of several complex interrelated parameters. Among others, some parameters to study are the water demand, pressure requirements, topography, location of resources, system reliability, and energy uses. In this paper, we focus on a real case of water distribution system in order to minimize installation costs by satisfying the given system requirements. We solve the problem by using state-of-the-art Constraint Programming techniques combined with Interval Analysis for rigorously handling continuous decision variables. Experimental results demonstrate the feasibility of the proposed approach, where the global optimum is reached in all instances and in reasonable runtime

SA to optimize the Multi-Period Water Distribution Network Design

The design optimization of the water distribution network is an important issue in modern cities. For this reason, we propose an optimization technique based on Simulated Annealing (SA) to solve the Water Distribution Network Design problem, considering multi-period restrictions with time varying demand patterns. The SA is improved with a local search procedure, yielding a hybrid SA, in order to obtain good quality networks designs. A broad experimentation using different test networks is carried out to test our proposal. Moreover, a comparison with an approach from the literature reveals the goodness of our proposal, the hybrid SA.XIX Workshop Agentes y Sistemas Inteligentes (WASI)Red de Universidades con Carreras en Informática (RedUNCI

Designing a Multi-Period Water Distribution Network with a Hybrid Simulated Annealing

The design optimization of water distribution systems, considering multi-period restrictions with time varying demand patterns, is a complex optimization problem present in modern cities. Taking into account this issue, we propose a hybrid optimization technique based on Simulated Annealing (HSA) enhanced with a local search procedure, in order to obtain good quality networks designs. The SA performance is very sensitive to the choice of the cooling scheme, which includes parameters as the cooling function and the initial temperature. For this reason, we have analysed the HSA behaviour using proportional, exponential, logarithmic and a new random cooling functions and three different initial temperatures. An extensive experimentation using different benchmark networks has been carried out to test our proposals. Moreover, a comparison with an approach from the literature has revealed the goodness to solve this network design problem.Sociedad Argentina de Informática e Investigación Operativ

Designing a Multi-Period Water Distribution Network with a Hybrid Simulated Annealing

The design optimization of water distribution systems, considering multi-period restrictions with time varying demand patterns, is a complex optimization problem present in modern cities. Taking into account this issue, we propose a hybrid optimization technique based on Simulated Annealing (HSA) enhanced with a local search procedure, in order to obtain good quality networks designs. The SA performance is very sensitive to the choice of the cooling scheme, which includes parameters as the cooling function and the initial temperature. For this reason, we have analysed the HSA behaviour using proportional, exponential, logarithmic and a new random cooling functions and three different initial temperatures. An extensive experimentation using different benchmark networks has been carried out to test our proposals. Moreover, a comparison with an approach from the literature has revealed the goodness to solve this network design problem.Sociedad Argentina de Informática e Investigación Operativ

Water distribution networks optimization considering unknown flow directions and pipe diameters

Water Distribution Networks (WDN) are present in a large number of industrial processes and urban centers. Reservoirs, pipes, nodes, loops, and pumps compose WDN and their design can be formulated as an optimization problem. The main objective is the minimization of the network cost, which depends on the pipe diameters and flow directions known a priori. However, in the design of new WDN in real industrial problems, flow directions are unknown. In the present paper, a disjunctive Mixed Integer NonLinear Programming (MINLP) model is proposed for the synthesis of WDN considering unknown flow directions. Two case studies are employed to test the model and global optimization techniques are used in its solution. Results show that the global optima WDN cost with the correct flow directions is obtained for the studied cases without the necessity of using additional software to calculate pressure drops and velocities in the pipes.The authors gratefully acknowledge the financial support from the National Council for Scientific and Technological Development —CNPq (Brazil), the Coordination for the Improvement of Higher Education Personnel —Process 88881.171419/2018-01 –CAPES (Brazil) and the Ministério de Economía, Industria y Competitividad CTQ2016-77968-C3-02-P (FEDER, UE)

Utilización de sistemas inteligentes para optimizar el diseño de redes de distribución de agua en General Pico - La Pampa

Esta línea de investigación aborda la resolución del problema del diseño óptimo de redes de distribución de agua multi-período, usando un algoritmo híbrido basado en la metaheurística Simulated Annealing. La propuesta algorítmica inicialmente es testeada satisfactoriamente con benchmarks presentes en el estado del arte. En consecuencia y dado que en la provincia de La Pampa el problema del acceso al agua es de tratamiento prioritario, los resultados obtenidos en esta línea de investigación son transferidos y aplicados a una variante de este problema para optimizar el diseño de redes de distribución de agua en un nuevo barrio de 505 hectáreas de la ciudad de General Pico.Eje: Agentes y Sistemas Inteligentes.Red de Universidades con Carreras en Informátic

Optimization of electrical energy consumption and level reliability of water supply system

Generally, high operational cost is associated with all water supply system. This is as a result of the high amount of electric energy consumption ascribed to the system due to its components. The water supply system of the Mara-Japan Industrial Institute (MJII), Beranang, Selangor is one of such system that suffers this challenge of high operational cost. In this paper we have applied the use of an Adaptive Weighted Sum Genetic Algorithm to optimize the system operations such that it minimizes the high energy consumption as well as ensuring the overall reliability of the water level in the reservoir. The results obtained from the optimized model of the system show a promising and a significant reduction to the tune of 34.97% in the amount of energy consumed as compared with that of normal operations

A Real Case of Multi-Period Water Distribution Network Design solved by a Hybrid Simulated Annealing

In this work, we propose an optimization solver based on a hybrid Simulated Annealing (HSA) to optimize the water distribution network design. The problem formulation includes multi-period restrictions with time-varying demand patterns. The HSA search process is affected by the Markov Chain Length (MCL), making modifications in the network design. For that reason, we studied the HSA behaviour by considering static and dynamic methods to compute the MCL. We test the algorithms by using networks reported in the state-of-the-art and also a real and new median size network that arises from a regional necessity. The experimentation suggests the use of a dynamic method, which exhibits the balance between efficacy and efficiency.Workshop: WASI – Agentes y Sistemas InteligentesRed de Universidades con Carreras en Informátic