Abstract This paper presents an application of fuzzy control technique in order to control pressure at entrance of a Water Distribution Pilot Network (RPDA, for its acronym in spanish), mesh with several points of consumption. Same is pressurized by a pump and motor assembly has power variation, which makes it difficult to stabilize control. Fuzzy controller implemented in system selects an optimum condition of operation regarding pressures available and engine output while maintaining pressure for network to meet demand. Evaluation of operating system energy gain with controller action was performed in comparison with operating system without control. Based on these results, fuzzy controller was satisfactory in controlling operating pressure during operation of distribution network.

Resumen Este trabajo se presenta una aplicación de la técnica de control difuso con el objetivo de controlar la presión en la entrada de una Red Piloto de Distribución de Agua (RPDA), malla, con diversos puntos de consumo. La misma se encuentra presurizada por un conjunto motor bomba y presenta variación del consumo, lo que dificulta la estabilización del control. El controlador difuso implantado en el sistema selecciona una condición excelente de operación referente a las presiones disponibles y el rendimiento del motor, manteniendo las presiones de la red constantes, para atender la demanda. La evaluación del logro energético del sistema operando con la acción del controlador fue realizada en comparación con el sistema operando sin control. De acuerdo a los resultados obtenidos, el controlador difuso fue considerado satisfactorio en el control de la presión del servicio durante la operación de la red de distribución.

RESUMO Este trabalho teve por objetivo propor um modelo computacional com vistas à calibração multivariada de modelos hidráulicos de sistemas de distribuição de água que possibilita a identificação de possíveis irregularidades, como: vazamentos, obstruções nas tubulações, válvulas inoperantes ou estranguladas e incompatibilidades na modelagem referente aos dados reais. Utiliza um algoritmo genético multiobjetivo no processo de calibração para ajustar as diferenças das variáveis de estado da rede, a fim de produzir informações compatíveis com suas respectivas redes reais. O modelo proposto permite utilizar até sete variáveis: a rugosidade, a demanda, a perda de carga singular, a cota topográfica, os vazamentos, os diâmetros e as válvulas, simultaneamente, ou qualquer combinação delas. A aplicação experimental foi realizada no Laboratório de Eficiência Energética e Hidráulica em Saneamento da Universidade Federal da Paraíba (LENHS/UFPB) com os dados do seu Sistema Piloto de Distribuição de Água (SPDA). Os resultados mostraram uma boa convergência com relação ao tempo de processamento e à aproximação dos dados medidos e calculados, assim como possibilitaram a identificação de problemas mediante análise dos parâmetros resultantes da calibração, o que proporciona subsídios para uma reabilitação mais precisa.

ABSTRACT This paper has aimed to propose a robust computational model with a view to multivariate calibration of hydraulic models of water distribution systems, enabling the identification of possible irregularities such as leaks, obstructions in the pipes, dead or strangled valves and incompatibilities in the modeling for the data real. Using a multiobjective genetic algorithm calibration process adjusts for differences of state variables of the network giving information consistent with their respective real networks. The proposed model allows use up to seven variables: the roughness, the demand, the headloss, the topographic, leaks, valves and diameters, simultaneously or any combination thereof. The experimental application was carried out at the Laboratory for Energy Efficiency and Water Sanitation Universidade Federal da Paraíba (UFPB) through its Pilot System for Water Distribution. The results showed a good convergence with respect to processing time and the approximation of the measured and calculated values, as well as enables the identification of problems by analyzing the parameters resulting from calibration, thus providing support for a more accurate rehabilitation.

RESUMO Esta pesquisa objetivou projetar um sistema de controle adaptativo para o modelamento e controle, em tempo real, de um sistema de distribuição de água. Os controladores atuaram no controle da pressão por meio da variação da velocidade de rotação do sistema de bombeamento e do ângulo de abertura de válvulas de controle. O sistema de controle é do tipo Variância Mínima Generalizado (GMV) autoajustável, cujos parâmetros foram estimados em tempo real pelo método dos mínimos quadrados recursivo (MQR). Os ensaios realizados na bancada experimental apresentaram resultados satisfatórios, com um erro máximo no controle de pressão de 2,12% (0,42 mca) e uma redução de 19,2% no consumo de energia elétrica para o sistema atuando na condição mais desfavorável.

ABSTRACT This research aimed to design an adaptive control system for modeling and real-time control of a water distribution system. Air traffic controllers acted on pressure control by varying the rotational speed of the pumping system and opening angle control valve. The system of control is of type Generalized Minimum Variance self-tuning, whose parameters were estimated in real time by the recursive least squares method. The tests performed on experimental workbench presented satisfactory results, with a maximum error on pressure control of 2.12% (0.42 mca) and a decrease of 19.2% in the consumption of electrical energy to the system in the most unfavorable condition.

O trabalho apresenta o desenvolvimento de um sistema Fuzzy para o controle de pressão de redes de distribuição de água, por meio da utilização de conversores de frequência acoplados aos conjuntos motor-bomba. Todo o estudo foi desenvolvido em uma bancada experimental instrumentalizada, simulando um sistema de abastecimento real. A utilização de conjuntos motor-bomba em paralelo gerou ao sistema um grande número de possibilidades de combinação das variações de velocidade dos conjuntos motor-bomba, com velocidades de rotação diferentes. O controlador Fuzzy identifica a melhor opção, referente ao consumo energético do sistema, e toma a decisão alusiva ao estado dos motores (ligado, desligado ou com rotação parcial). Todo esse processo é realizado na condição de atender a demanda de vazão do sistema, além de manter a pressão constante com o menor consumo energético possível.

The paper presents the development of a Fuzzy system for the pressure control of distribution of water through the use of frequency converters coupled to the motor-pump assemblies. The entire study was conducted in an instrumentalized bench trial simulating a real supply system. The use of pump-motor sets in parallel with the system generated a great number of combination possibilities of variations in speed of the motor-pump assemblies, with different speeds of rotation. The Fuzzy controller identifies the best option for the energy consumption of the system and makes the decision alluding to the state of the engines (on, off or partial rotation). This entire process is performed under the condition of meeting the demand flow system, and maintain constant pressure with the lowest possible energy consumption.

This paper presents a fuzzy system to control the pressure in a water distribution network, by using valves and controlling the rotor speed of the pumping systems. The variable frequency drive tracks the minimum head of the pumping system, while the control valves have the function of eliminating the excess pressure at various points of the network. The control system can track any reference pressure value and there is no limit for the number of monitored points. Experiments were carried out to demonstrate the fuzzy system's efficiency. By extrapolating the results achieved in the experimental setup to a real hydraulic network with leakages and no pressure control, the volumetric losses could be reduced by more than 56%. The experiments showed that the system is robust enough to control the pressure of an experimental setup of water distribution. Besides, the proposed system can be easily applied to similar water supply systems and would help to reduce the consumption of water and electricity, as well as to reduce the maintenance costs.

This study is aimed at developing a pipe-sizing model for a water distribution system. The optimal solution minimises the system's total cost, which comprises the hydraulic network capital cost, plus the capitalised cost of pumping energy. The developed model, called Lenhsnet, may also be used for economical design when expanding existing hydraulic networks. The methodology developed includes an iterative dynamic calculation process as well as a hydraulic simulation model. The performance of the method is tested against 4 benchmark examples in the literature. The results obtained show the feasibility of this model, presenting it as a viable alternative for water distribution systems. The method is easily used, once it is performed under EPANET2 software interface.

This paper presents an iterative method for the optimisation of the total costs for the rehabilitation of water-supply pipe networks with flow and pressure deficiency at the consumer nodes. The procedure is based on the exchange gradient concept of Granados for the economic design of pressurised networks. The substitution of pipe sections, relining and increase in pumping head are considered as being rehabilitation options. An initial solution is obtained for the deficient network by determining the required pumping head that would meet the pressure and discharge requirements at all the nodes. Subsequently, the pumping head is reduced in stages and for each reduction; the network of minimum cost is obtained by the substitution or relining of individual pipes in part or in full. The optimal solution is reached when the marginal annual cost of pipe rehabilitation exceeds the reduction in annual pumping costs.

RESUMO O uso da irrigação por gotejamento vem crescendo nos últimos anos, principalmente pela grande economia no consumo da água que a mesma proporciona, no entanto, por se tratar de um sistema fixo, os elevados custos de instalação tendem a inibir a utilização desta técnica. Buscando-se aproveitar as vantagens que a irrigação localizada oferece, o presente trabalho tem como objetivo fazer uma adaptação no método de otimização econômica integrada (aplicada a sistemas de irrigação por aspersão convencional, desenvolvida por Gomes) à irrigação por gotejamento. Tal metodologia visa à minimização do custo-conjunto da rede de distribuição, energia de bombeamento e equipamentos das parcelas. Os resultados obtidos foram consistentes com a teoria da referida metodologia, o que demonstra sua eficácia, tanto na irrigação por aspersão convencional como, também, no gotejamento.

ABSTRACT The use of trickle irrigation has increased during the past few years, mainly due to greater economy in water consumption. However, the fact of being a fixed system raises installation costs and inhibits its adoption. In order to get the advantages that localized irrigation offers, the objective of this work is to adopt the integrated economic optimization method (applied to conventional sprinkle irrigation systems, developed by Gomes) to trickle irrigation. This methodology intends to minimize costs of the distribution network, pumping energy and plot equipment. The results obtained were consistent with the methodology used in this work, showing its validity for conventional sprinkle irrigation as well as trickle irrigation.

RESUMO O método Granados de otimização, desenvolvido para redes ramificadas, foi associado à metodologia dos anéis de Hardy Cross e aplicado a redes malhadas. Os resultados obtidos mostram uma economia significativa no custo total das tubulações e revelam a potencialidade dessa ferramenta, que assume, definitivamente, o seu lugar no dimensionamento de redes pressurizadas.

ABSTRACT This article extends Granados method from branched to looped networks and shows how to apply it to find a new solution to an already dimensioned real-world system, comparing the new solutions against the previous one. The conclusion is that cost optimization methods bring such a significant cost economy that definitily grants them to be almost mandatorily advisable for sizing pressured water distribution systems.