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Publications

Journal Articles

Wastewater Pump Control under Mechanical Wear

Fecarotta, O., Martino, R., & Morani, M. C. (2019). Wastewater Pump Control under Mechanical Wear. Water, 11(6), 1210. 

Abstract:

With reference to a classical wet tank equipped with a wastewater submersible pump, in this research, an advanced numerical model has been used in order to obtain the optimal pump scheduling of on/off operation and variable pump speed. Then, in order to evaluate the time decay of pump performances, the mechanical wear has been artificially simulated and the performance curves have been experimentally obtained for different rotational speeds. Finally, the benefits, as well as the feasibility, of pump scheduling have been evaluated for differing operating conditions. According to the results, the optimal pump scheduling achieves large energy savings up to 43%, for soft mechanical wear. If the mechanical wear is considered, the energy savings are large as well, between 35.60% and 26.70%, for medium and hard mechanical wear, respectively. On the other hand, the limitation of such a strategy has been highlighted: the feasibility of pump scheduling is limited by the elevation of the downstream tank. According to the results, energy savings can be achieved until the elevation of the downstream tank is 67% of the pressure head at the best efficiency point, whereas such percentage decreases to 50% for hard mechanical wear. Finally, the results show that plant efficiency is strongly affected by the mechanical wear: an accurate maintenance of the pumping system is therefore recommended in order to attenuate the time decay of pump performances.

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Optimal energy efficiency of isolated PAT systems by SEIG excitation tuning

João F.P. Fernandes, Modesto Pérez-Sánchez, F. Ferreira da Silva, P. Amparo López-Jiménez, Helena M. Ramos, P.J. Costa Branco, Optimal energy efficiency of isolated PAT systems by SEIG excitation tuning, Energy Conversion and Management, Volume 183, 2019,Pages 391-405

Abstract:

The use of pump working as turbine (PAT) was identified by many researchers as a way to improve the energy efficiency in the water systems. However, the majority of the researches consider the hydraulic machine connected to the electrical grid, which may not fit best when these recovery systems are located in rural or remote areas. To improve the efficiency in these recovery systems for rural areas, this research contributes for a further study and optimization of the off-grid PAT systems with induction generators. The current manuscript proposes a methodology to obtain the best efficiency of the PAT-SEIG (Self-Excited Induction Generator) system when operating under different speeds and loads. For these systems, the selection of capacitors for the SEIG is critical to maximizing the energy efficiency. A methodology is proposed to estimate and select the correct SEIG model parameters and, thus, compute the best capacitor values to improve the PAT-SEIG energy efficiency. Special attention is given to the impact the SEIG parameters have in the efficiency of the recovery system. The accuracy of the analytical model improved, reducing the error between analytical and experimental results from 50.8% (for a model with constant parameters) to 13.2% (with parameters changing according to the operating point of the system). These results showed an increase of the overall PAT system efficiency from 26% to 40% for the analyzed case study.

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Flow Conditions for PATs Operating in Parallel: Experimental and Numerical Analyses

Simão, M.; Pérez-Sánchez, M.; Carravetta, A.; Ramos, H.M. Flow Conditions for PATs Operating in Parallel: Experimental and Numerical Analyses. Energies 2019, 12, 901.

Abstract

Micro-hydro systems can be used as a promising new source of renewable energy generation, requiring a low investment cost of hydraulic, mechanical, and electrical equipment.

The improvement of the water management associated with the use of pumps working as turbines (PATs) is a real advantage when the availability of these machines is considered for a wide range of flow rates and heads. Parallel turbomachines can be used to optimize the flow management of the system. In the present study, experimental tests were performed in two equal PATs working in parallel and in single mode. These results were used to calibrate and validate the numerical simulations.

The analysis of pressure variation and head losses was evaluated during steady state conditions using different numerical models (1D and 3D). From the 1D model, the installation curve of the system was able to be defined and used to calculate the operating point of the two PATs running in parallel.

As for the computational fluid dynamics (CFD) model, intensive analysis was carried out to predict
the PATs behavior under different flow conditions and to evaluate the different head losses detected within the impellers. The results show system performance differences between two units running in parallel against a single unit, providing a greater operational flow range. 

The performance in parallel design conditions show a peak efficiency with less shock losses within the impeller. Furthermore, by combining multiple PATs in parallel arrangement, a site’s efficiency increases, covering a wide range of applications from the minimum to the maximum flow rate. The simulated flow rates were in good agreement with the measured data, presenting an average error of 10%.

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Pump-as-Turbine Selection Methodology for Energy Recovery in Irrigation Networks: Minimising the Payback Period

Miguel Crespo Chacón, Juan Antonio Rodríguez Díaz, Jorge García Morillo and Aonghus McNabola,
Pump-as-Turbine Selection Methodology for Energy Recovery in Irrigation Networks: Minimising the Payback Period (2019),
Water 2019, 11(1), 149 

Abstract

In pressurized irrigation networks, energy reaches around 40% of the total water costs. Pump-as-Turbines (PATs) are a cost-effective technology for energy recovery, although they can present low efficiencies when operating outside of the best efficiency point (BEP). Flow fluctuations are very important in on-demand irrigation networks. This makes flow prediction and the selection of the optimal PAT more complex. In this research, an advanced statistical methodology was developed, which predicts the monthly flow fluctuations and the duration of each flow value. This was used to estimate the monthly time for which a PAT would work under BEP conditions and the time for which it would work with lower efficiencies. In addition, the optimal PAT power for each Excess Pressure Point (EPP) studied was determined following the strategy of minimising the PAT investment payback period (PP). The methodology was tested in Sector VII of the right bank of the Bembézar River (BMD), in Southern Spain. Five potential sites for PAT installation were found. The results showed a potential energy recovery of 93.9 MWh and an annual energy index per irrigated surface area of 0.10 MWh year−1 ha−1. Renewable energy will become increasingly important in the agriculture sector, to reduce both water costs and the contribution to climate change. PATs represent an attractive technology that can help achieve such goals.

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Flow Velocity Distribution Towards Flowmeter Accuracy: CFD, UDV, and Field Tests

Mariana Simão, Mohsen Besharat, Armando Carravetta and Helena M. Ramos,  (2018) Flow Velocity Distribution Towards Flowmeter Accuracy: CFD, UDV, and Field Tests, Water 2018, 10, 1807; doi:10.3390/w10121807

Abstract

Inconsistences regarding flow measurements in real hydraulic circuits have been detected. Intensive studies stated that these errors are mostly associated to flowmeters, and the low accuracy is connected to the perturbations induced by the system layout. In order to verify the source of this problem, and assess the hypotheses drawn by operator experts, a computational fluid dynamics (CFD) model, COMSOL Multiphysics 4.3.b, was used. To validate the results provided by the numerical model, intensive experimental campaigns were developed using ultrasonic Doppler velocimetry (UDV) as calibration, and a pumping station was simulated using as boundary conditions the values measured in situ. After calibrated and validated, a new layout/geometry was proposed in order to mitigate the observed perturbations. 

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A Comparison of Energy Recovery by PATs against Direct Variable Speed Pumping in Water Distribution Networks

Maria Cristina Morani, Armando Carravetta, Giuseppe Del Giudice, Aonghus McNabola and Oreste Fecarotta; A Comparison of Energy Recovery by PATs against Direct Variable Speed Pumping in Water Distribution Networks; Fluids 2018, 3(2), 41; doi:10.3390/fluids3020041

Hydro-power energy recovery in pressurized irrigation networks

Garcia Morillo, J., McNabola, A., Camacho, E., Montesisnos, P., Rodriguez-Diaz, J.A., Hydro-power energy recovery in pressurized irrigation networks: A case study of an Irrigation District in the South of Spain., Agricultural Water Management, 204, 2018, p17 - 27

Electrical behaviour of the pump working as turbine in off grid operation

Capelo, B; Pérez-Sánchez, M; Fernandes, JFP; Ramos, H.M; López-Jiménez, P.A; Costa Branco, P.J. Electrical behaviour of the pump working as turbine in off grid operation, Applied Energy 2017, 208, 302-311

CFD Analyses and Experiments in a PAT Modeling

Pérez-Sánchez, M.; Simão, M.; López-Jiménez, P.A.; Ramos, H.M. CFD Analyses and Experiments in a PAT Modeling: Pressure Variation and System Efficiency. Fluids 2017, 2, 51.

Urban Floods Adaptation and Sustainable Drainage Measures

Ramos, H.M.; Pérez-Sánchez, M.; Franco, A.B.; López-Jiménez, P.A. Urban Floods Adaptation and Sustainable Drainage Measures. Fluids 2017, 2, 61.

Velocities in a Centrifugal PAT Operation: Experiments and CFD Analyses

Simão M, Pérez-Sánchez M, Carravetta A, López-Jiménez P, Ramos HM. Velocities in a Centrifugal PAT Operation: Experiments and CFD Analyses. Fluids. 2018; 3(1):3.

Books

The Northern Ireland experience in Transnational Programmes

SEUPB brochureThis review by the Special EU Programmes Body provides an overview of the INTERREG VB Transnational / VC Interregional Programmes, featuring some of the many achievements which have been made within Northern Ireland.  This includes the REDAWN project.

From blue growth and green mobility, to remote area connectivity, ageing populations and migration, Interreg transnational cooperation is fostering strong partnerships where national, regional & local authorities; academia; NGOs;and private sector enterprises work together to tackle today’s complex challenges. These multi-sector alliances build on regional strengths and address real challenges facing real places and people across Europe.

Download a pdf of the brochure here

#EU in my region: 30 years of Partnership: Stories of Countries & Regions Sharing Knowledge, Ideas & Innovation

#EU in my region brochureIt is impossible to capture the full extent and impact of Interreg programmes but in these pages you can enjoy a snapshot of projects supported by the Atlantic Area Programme, Northern Periphery and Arctic Programme and Interreg Europe, including REDAWN.

More than four decades have now elapsed since Ireland joined what was then the Common Market in 1973.

Throughout that period, Ireland has been a major beneficiary of EU Cohesion funding. The Union’s Cohesion policy lies at the heart of European integration and solidarity and proves that these words have real meaning for every part of the Union. It has been one of Europe’s success stories.

Everywhere you travel in Ireland you can see the distinctive Structural Funds logo on plaques and signs, which highlights the many ways we have benefitted from Cohesion funding – from major infrastructure road and rail projects to smaller community projects, to projects aimed at helping people acquire new skills and find better jobs. All serve to underline the very real ways Ireland has benefitted from its membership of the European Union. 

But Cohesion funding has done more than that. It has enabled Ireland to take part in European Territorial Cooperation – or INTERREG - programmes with other Member States and neighbouring countries.

Download a pdf of the brochure here

Pumps as Turbines: Fundamentals and Applications

Carravetta, A;  Houreh, S.D; Ramos, H.M. Pumps as Turbines: Fundamentals and Applications, Springer, 2018.

This book provides users, pump manufactures, engineers, researchers and students with extensive information about pump’s behavior in reverse operation. It reports on cutting-edge methods for selecting the proper PAT and improving PAT’s efficiency, discusses PAT’s reliability, economic issues and environmental impact as well. The book describes in detail electromechanical equipment of PAT systems, their installation and operation, and gives important practical insight into the use of PAT in water transmission and distribution systems, as part of thermal power plants and cooling systems, in oil distribution systems and other systems as well. It reports on different types on PAT control modes as well as on numerical methods useful for PAT analysis and implementation.  All in all, the book represents a comprehensive practice-oriented reference-guide to design engineers, as well as PAT general users and manufactures. It also provides researchers with extensive technical information on the use of PAT thus fostering new discussions and ideas to improve current methods and cope with future challenges.

Conference Proceedings

Reducing the Energy Dependency of Water Networks in Irrigation, Public Drinking Water, and Process Industry: REDAWN Project.

Carravetta, A.; Fecarotta, O.; Ramos, H.M.; Mello, M.; Rodriguez-Diaz, J.A.; Morillo, J.G.; Adeyeye, K.; Coughlan, P.; Gallagher, J.; McNabola, A. Reducing the Energy Dependency of Water Networks in Irrigation, Public Drinking Water, and Process Industry: REDAWN Project. Proceedings 2018, 2, 681.

https://doi.org/10.3390/proceedings2110681

Energy Saving Measures in Pressurized Irrigation Networks: A New Challenge for Power Generation.

Morillo, J.G.; Díaz, J.A.R.; Crespo, M.; McNabola, A. Energy Saving Measures in Pressurized Irrigation Networks: A New Challenge for Power Generation. Proceedings 20182, 1440.

https://doi.org/10.3390/proceedings2231440

Fostering Renewable Energies and Energy Efficiency in the Water Sector Using PATs and Wheels

Ramos, H.M.; Simão, M.; McNabola, A.; Novara, D.; Carravetta, A. Fostering Renewable Energies and Energy Efficiency in the Water Sector Using PATs and Wheels. Proceedings 2018, 2, 1438.

http://www.mdpi.com/2504-3900/2/23/1438/pdf

Energy recovery using PAT

Simão, M., Besharat, M. ,Ramos, H.M; (2018) Energy recovery using PAT,  Silva-Afonso A and Rodrigues-Pimental, C. (Eds), Proceedings of the Water Efficiency Conference 2018, 5-7 September 2018, Aveiro Portugal: WATEF Network/ University of Bath.

 

Hydropower energy recovery in water pipe networks: spatial regression analysis using GIS, assessing the correlation between energy recovery potential and geographical data

Dorde Mitrovic, Juan Antonio Rodriguez Diaz, Jorge Garcia Morillo, Paul Coughlan, John Gallagher, Aonghus McNabola, (2018) Hydropower energy recovery in water pipe networks: spatial regression analysis using GIS, assessing the correlation between energy recovery potential and geographical data, Silva-Afonso A and Rodrigues-Pimental, C. (Eds), Proceedings of the Water Efficiency Conference 2018, 5-7 September 2018, Aveiro Portugal: WATEF Network/ University of Bath.

Reducing the Energy Dependency of Water Pipe Networks in the Atlantic Area of Europe

Carravetta, A, Fecarotta, O., Ramos, H.M, Mello, M., Rodriguez-Diaz, J.A., Garica-Morillo, J., Adeyeye, K., Coughlan, P., Gallagher, J., McNabola, A., Reducing the Energy Dependency of Water Pipe Networks in the Atlantic Area of Europe: Case studies in irrigation, public drinking water and process industry, 3rd International EWaS (Efficient Water Systems) Conference, Greece, 27-30 June, 2018, pp1-7

Potential Energy Recovery using Micro-Hydropower Technology in Irrigation Networks

Crespo Chacon M., Rodriguez Diaz JA., Garcia Morillo J., Gallagher J., Coughlan P., McNabola A., Potential Energy Recovery using Micro-Hydropower Technology in Irrigation Networks: Real-World Cases Studies in the South of Spain, 3rd International EWaS (Efficient Water Systems) Conference, Greece, 27-30 June, 2018, pp1-8

Posters

Hydropower energy recovery potential from irrigation networks

M. Crespo*, A. McNabola, Hydropower energy recovery potential from irrigation networks, Presented at ENVIRON2018, Cork, Ireland.

Hydropower energy recovery potential of water distribution networks

D. Mitrovic*, A. McNabola, Hydropower energy recovery potential of water distribution networks: Assessing the correlation between the potential and geographical data, Presented at ENVIRON2018, Cork, Ireland.

Presentations

Hydropower energy recovery in water pipe networks

Potential Energy Recovery using MHP in Irrigation Networks: Case studies in Southern Spain