Pumped-Storage and Hybrid Energy Solutions Towards the Improvement of Energy Efficiency in Water Systems

Communications engineering / telecommunication

Poverty measures and poverty orderings

We examine the conditions under which unanimous poverty rankings of income distributions can be obtained for a general class of poverty indices. The “per-capita income gap” and the Shorrocks and Thon poverty measures are particular members of this class. The conditions of dominance are stated in terms of comparisons of the corresponding TIP curves and areas.Peer Reviewe

Low-head energy recovery: tubular propeller with 5 blades

[ES] Os sistemas de abastecimento, distribuição e drenagem do setor da água são um dos principais tipos de sistemas hidráulicos artificiais com potencial para a instalação de micro-hídricas. Apesar de existirem algumas aplicações de mini-hidroeletricidade nas condutas de adução, as redes de distribuição de águas urbanas e de rega continuam a ser pouco exploradas. Desta forma, com o objetivo de aproveitar o potencial energético, estudou-se uma turbina hélice tubular com 5 pás inicialmente desenvolvida no âmbito do projeto europeu HYLOW em 2008 e testada em HES-SO Valais. Modelações numéricas foram efetuadas por forma a avaliar o comportamento do fluido no interior da turbina. As simulações apresentaram uma boa aproximação com os ensaios experimentais, com valores de desvio abaixo dos 5%.[EN] Water supply, distribution and drainage systems are one of the main types of artificial hydraulic systems with potential for the installation of micro-turbines. Although there are some mini-hydropower applications in pipe systems, urban water and irrigation networks are still under-exploited. Thus, in order to exploit the energy potential, a 5-blade tubular propeller turbine, initially developed as part of the European HYLOW project in 2008 and tested in HES-SO Valais, was studied. Numerical models were performed to evaluate the behavior of the flow inside the turbine. The simulations presented a good approximation with the experimental tests, with deviation values below 5%.Os autores agradecem ao projeto REDAWN (Redução da Dependência Energética nas Redes de Águas da Área Atlântica) EAPA_198 / 2016 do PROGRAMA INTERREG ATLÂNTICO 2014-2020, ao CERIS e aos Laboratórios de Hidráulica do DECivile HES-SO Valais, pelo apoio no desenvolvimento dos ensaios experimentais.Simao, M.; Ramos, H. (2020). Recuperação de energia de baixa queda: turbina hélice tubular com 5 pás. Ingeniería del agua. 24(4):285-294. https://doi.org/10.4995/ia.2020.13636OJS285294244Abbasi, T. 2011. Small hydro and the environmental implications of its extensive utilization. Renewable and Sustainable Energy Reviews, 15, 2134-2143. https://doi.org/10.1016/j.rser.2010.11.050Aggidis, G.A. 2014. Hydro turbine prototype and generation of performance curves: Fully automated approach. Renewable Energy, 71, 433-441. https://doi.org/10.1016/j.renene.2014.05.043Ayli, E., Celebioglu, K., Aradag, S. 2016. CFD based Hill chart construction and similarity study of prototype and model Francis turbines for experimental tests. 12th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics.Biner, D., Hasmatuchi, V., Avellan, F., Münch-Alligné, C. 2015. Design & performance of a hydraulic microturbine with counterrotating runners. 5th International Youth Conference on Energy (IYCE), Pisa, pp. 1-10. https://doi.org/10.1109/IYCE.2015.7180737Carravetta, A., Del Giudice, G., Fecarotta, O., Ramos, H.M. 2012. Energy Production in Water Distribution Networks: A PAT Design Strategy. Water Resource Management, 26, 3947-3959. https://doi.org/10.1007/s11269-012-0114-1Caxaria, G., Mesquita e Sousa, D., Ramos, H.M. 2011. Small scale hydropower: generator analysis and optimization for water supply systems. Sweden, European council for an energy efficient economy. In World Renewable Energy Congress-Sweden; 8-13 May; 2011; Linköping; Sweden (No. 057, pp. 1386-1393). Linköping University Electronic Press. https://doi.org/10.3384/ecp110571386Coelho, B., Andrade-Campos, A. 2014. Efficiency achievement in water supply systems-A review. Renewable and Sustainable Energy Reviews, 30, 59-84. https://doi.org/10.1016/j.rser.2013.09.010Corcoran, L., McNabola, A., Coughlan, P. 2015. Optimization of Water Distribution Networks for Combined hydropower Energy Recovery and Leakage Reduction. Journal of Water Resources Planning and Management, 142(2). https://doi.org/10.1061/(ASCE)WR.1943-5452.0000566Elbatran, A. Yaakob, O.B., Ahmed, Y.M., Shabara, H.M. 2015. Operation, performance and economic analysis of low head micro-hydropower turbines for rural and remote areas: A review. Renewable and Sustainable Energy Reviews, 43, 40-50. https://doi.org/10.1016/j.rser.2014.11.045Heller, V. 2011. Scale effects in physical hydraulic engineering models. Journal of Hydraulic Research, 49, 293-306. https://doi.org/10.1080/00221686.2011.578914Luna-Ramírez, A., Campos-Amezcua, A., Dorantes-Gómez, O., Mazur-Czerwiec, Z., Muñoz-Quezada, R. 2016. Failure analysis of runner blades in a Francis hydraulic turbine - Case study. Engineering Failure Analysis, 59, 314-325. https://doi.org/10.1016/j.engfailanal.2015.10.020Paish, O. 2002. Small hydro power: technology and current status. Renewable and Sustainable Energy Reviews, 6(6), 537-556. https://doi.org/10.1016/S1364-0321(02)00006-0Ramos, H.M., Borga, A., Simão, M. 2009. New design for low-power energy production in water pipe systems. Water Science and Engineering, 2(4), 69-84. https://doi.org/10.3882/j.issn.1674-2370.2009.04.007Ramos, H.M., Simão, M., Borga, A. 2013. Experiments and CFD Analyses for a New Reaction Microhydro Propeller with Five Blades. Journal of Energy Engineering, 139, 109-117. https://doi.org/10.1061/(ASCE)EY.1943-7897.0000096Samora, I., Hasmatuchi, V., Münch-Alligné, C., Franca, M.J., Schleiss, A.J., Ramos, H.M. 2016a. Experimental characterization of a five blade tubular propeller turbine for pipe inline installation. Renewable Energy, 95, 2016, 356-366. https://doi.org/10.1016/j.renene.2016.04.023Samora, I., Schleiss, A., Ramos, H.M. 2016b. Optimization of low-head hydropower recovery in water supply networks. https://doi.org/10.5075/epfl-thesis-7126.Simão, M., Pérez-Sánchez, M., Carravetta, A., López-Jiménez, P., Ramos, H.M. 2017. Velocities in a centrifugal PAT operation: Experiments and CFD analyses. Fluids, 3(3). https://doi.org/10.3390/fluids3010003Williamson, S.J., Stark, B.H., Booker, J.D. 2014. Low head pico hydro turbine selection using a multi-criteria analysis. Renewable Energy, 61, 43-50. https://doi.org/10.1016/j.renene.2012.06.02

Experimental and numerical analysis of a water emptying pipeline using different air valves

The emptying procedure is a common operation that engineers have to face in pipelines. This generates subatmospheric pressure caused by the expansion of air pockets, which can produce the collapse of the system depending on the conditions of the installation. To avoid this problem, engineers have to install air valves in pipelines. However, if air valves are not adequately designed, then the risk in pipelines continues. In this research, a mathematical model is developed to simulate an emptying process in pipelines that can be used for planning this type of operation. The one-dimensional proposed model analyzes the water phase propagation by a new rigid model and the air pockets effect using thermodynamic formulations. The proposed model is validated through measurements of the air pocket absolute pressure, the water velocity and the length of the emptying columns in an experimental facility. Results show that the proposed model can accurately predict the hydraulic characteristic variables. © 2017 by the authors

Effect of a commercial air valve on the rapid filling of a single pipeline: A numerical and experimental analysis

The filling process in water pipelines produces pressure surges caused by the compression of air pockets. In this sense, air valves should be appropriately designed to expel sufficient air to avoid pipeline failure. Recent studies concerning filling maneuvers have been addressed without considering the behavior of air valves. This work shows a mathematical model developed by the authors which is capable of simulating the main hydraulic and thermodynamic variables during filling operations under the effect of the air valve in a single pipeline, which is based on the mass oscillation equation, the air-water interface, the polytropic equation of the air phase, the air mass equation, and the air valve characterization. The mathematical model is validated in a 7.3-m-long pipeline with a 63-mm nominal diameter. A commercial air valve is positioned in the highest point of the hydraulic installation. Measurements indicate that the mathematical model can be used to simulate this phenomenon by providing good accuracy. © 2019 by the authors.This work is supported by Fundacao para a Ciencia e Tecnologia (FCT), Portugal (grant number PD/BD/114459/2016)

Effect of the non-stationarity of rainfall events on the design of hydraulic structures for runoff management and its applications to a case study at Gordo Creek watershed in Cartagena de Indias, Colombia

The 24-h maximum rainfall (P 24h-max ) observations recorded at the synoptic weather station of Rafael Núñez airport (Cartagena de Indias, Colombia) were analyzed, and a linear increasing trend over time was identified. It was also noticed that the occurrence of the rainfall value (over the years of record) for a return period of 10 years under stationary conditions (148.1 mm) increased, which evidences a change in rainfall patterns. In these cases, the typical stationary frequency analysis is unable to capture such a change. So, in order to further evaluate rainfall observations, frequency analyses of P 24h-max for stationary and non-stationary conditions were carried out (by using the generalized extreme value distribution). The goodness-of-fit test of Akaike Information Criterion (AIC), with values of 753.3721 and 747.5103 for stationary and non-stationary conditions respectively, showed that the latter best depicts the increasing rainfall pattern. Values of rainfall were later estimated for different return periods (2, 5, 10, 25, 50, and 100 years) to quantify the increase (non-stationary versus stationary condition), which ranged 6% to 12% for return periods from 5 years to 100 years, and 44% for a 2-year return period. The effect of these findings were tested in the Gordo creek watershed by first calculating the resulting direct surface runoff (DSR) for various return periods, and then modeling the hydraulic behavior of the downstream area (composed of a 178.5-m creek's reach and an existing box-culvert located at the watershed outlet) that undergoes flooding events every year. The resulting DSR increase oscillated between 8% and 19% for return periods from 5 to 100 years, and 77% for a 2-year return period when the non-stationary and stationary scenarios were compared. The results of this study shed light upon to the precautions that designers should take when selecting a design, based upon rainfall observed, as it may result in an underestimation of both the direct surface runoff and the size of the hydraulic structures for runoff and flood management throughout the city. © 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license

Existence and concentration of solutions for a class of biharmonic equations

Some superlinear fourth order elliptic equations are considered. Ground states are proved to exist and to concentrate at a point in the limit. The proof relies on variational methods, where the existence and concentration of nontrivial solutions are related to a suitable truncated equation.Comment: 18 page