Unreported leaks location using pressure and flow sensitivity in water distribution networks

[EN] Water distribution systems are made up of many interdependent elements that enable water supply to meet a demand that is variable in time and space. One of the main concerns for utility managers is quickly locating and repairing a leak after detection, during regular network water balance. This paper presents a two-stage methodology for locating a leak that is based on the hydraulic model of the network, and, particularly, on the conservation equations that govern network behaviour. In the first stage, the sensitivity of each element (nodes and pipes) is obtained for a given demand increase in any node. In the second stage, that sensitivity is combined with additional real data provided by the (possibly) existing pressure sensors and flowmeters installed throughout the network. As a final result, the system of equations thus obtained produces the theoretical leak flow at each network node that matches the network conditions. A subsequent analysis of the leak flows obtained highlights the node or nodes in which the leak is occurring. The presented methodology is applied and assessed in a case study.Salguero Barceló, FJ.; Cobacho Jordán, R.; Pardo Picazo, MA. (2019). Unreported leaks location using pressure and flow sensitivity in water distribution networks. Water Science & Technology: Water Supply. 19(1):11-18. https://doi.org/10.2166/ws.2018.048S111819

Standalone direct pumping photovoltaic system or energy storage in batteries for supplying irrigation networks. Cost analysis

[EN] Solar photovoltaic systems have become one of the most popular topics in the water management industry. Moreover, irrigation networks are water- and energy-hungry, and utilitymanagers are likely to adaptwater consumption (and consequently energy demand) to the hours inwhich there is energy availability. In countries such as Spain (with high irradiance values), solar energy is an available green alternative characterised by zero electricity costs and significantly lower environmental impact. In this work, several types of irrigation scheduled programmes (according to different irrigation sectors) that minimise the number of photovoltaic solar panels to be installed are studied; moreover, the effects of the variable costs linked to energy (energy and emissions costs) are presented. Finally, the effect of incorporating batteries for storing energy to protect the system against emergencies, such as unfavourable weather, is proposed. The irrigation hours available to satisfywater demands are limited by sunlight; they are also limited by the condition that the irrigation schedule type has to be rigid (predetermined rotation) and that the pressure at any node has to be above minimumpressure required by standards. A real case study is performed, and the results obtained demonstrate that there is no universal solution; this is because the portfolio of alternatives is based on investments for purchasing equipment at present and also on future energy savings (revenues). Apart from these two values, there is an economic value (equivalent discontinuous discount rate), which also influences the final results.This work was supported by the research project “GESAEN” through the 2016 call of the Vicerrectorado de Investigación, Desarrollo e Innovación de la Universidad de Alicante GRE-16-08.Pardo Picazo, MA.; Manzano Juarez, J.; Valdes-Abellan, J.; Cobacho Jordán, R. (2019). Standalone direct pumping photovoltaic system or energy storage in batteries for supplying irrigation networks. Cost analysis. The Science of The Total Environment. 673:821-830. https://doi.org/10.1016/j.scitotenv.2019.04.050S82183067