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Elena Vagnoni

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Publications associées (38)

Assessing the energy potential of modernizing the European hydropower fleet

Anton Schleiss, Elena Vagnoni

About 50% of all hydropower plants (HPPs) worldwide were originally commissioned more than 40 years ago, so that the advanced age of the fleet is a major concern across all continents, and especially in Europe. The modernization of HPPs can generate severa ...

Elsevier2021

Experimental facility for reduced scale model testing of hydraulic machines hybridized with a battery energy storage system

Sidi-Rachid Cherkaoui, Mario Paolone, Martin Seydoux, Elena Vagnoni, Francesco Gerini

With a continuously growing share of non-dispatchable renewable energy sources in the power mix, flexibility in hydropower provision is becoming fundamental. The major role played by hydropower in frequency regulation in the last years has underlined the p ...

IOP PUBLISHING LTD2021

Numerical investigation on the volute cutwater for pumps running in turbine mode

Elena Vagnoni, Alessandro Morabito

The hydropower sector has recently raised the interest in pump as turbine (PaT) that can be a valid trade-off between capital cost and performance in micro-scale installations. Nevertheless, the modest efficiency of PaTs often restricts their exploitation. ...

Pergamon-Elsevier Science Ltd2021

Dynamic behaviour of a Francis turbine during voltage regulation in the electrical power system

François Avellan, Elena Vagnoni

Hydroelectric units can be operated in synchronous condenser mode to provide reactive power to the electrical power system (EPS) for voltage regulation. In this operating mode, the hydraulic turbine consumes active power and in case of hydroelectric units ...

2020

Underground Pumped Storage Hydropower Case Studies in Belgium: Perspectives and Challenges

Elena Vagnoni, Alessandro Morabito

To avoid the geographical and topographical prerequisites of the conventional pumped hydro energy storage, the use of underground cavities as water reservoirs allows countries without steep topography, such as Belgium, to increase the potential of the ener ...

MDPI2020

Oxygen diffusion through air–water free surfaces in a pump–turbine operating in condenser mode

François Avellan, Elena Vagnoni, Loïc Andolfatto, Pierre Leroy

The present research aims at understanding the mass transfer of air into water in a reversible pump turbine operating in condenser mode. In particular, the diffusion of oxygen through the water free-surface both in the vaneless gap between the impeller bla ...

2019

Hydraulic performance evaluation of a micro-turbine with counter rotating runners by experimental investigation and numerical simulation

François Avellan, Cécile Münch-Alligné, Elena Vagnoni, Loïc Andolfatto

The development of energy recovery systems on existing water utility networks is a new challenge for increasing the sustainability of electricity generation mix. The concept of the new micro-turbine with counter rotating runners braces this goal by allowin ...

Pergamon-Elsevier Science Ltd2018

Interaction of a rotating two-phase flow with the pressure and torque stability of a reversible pump-turbine operating in condenser mode

François Avellan, Elena Vagnoni, Loïc Andolfatto, Pierre Leroy

The operation of a reversible pump-turbine in condenser mode requires to dewater the impeller by closing the guide vanes and injecting compressed air in the draft tube cone to reduce the friction torque on the impeller blades. A water discharge is injected ...

2019

Rotating air-water ring in the vaneless gap of a pump-turbine operating in condenser mode

François Avellan, Elena Vagnoni, Loïc Andolfatto, Pierre Leroy

The rotating air-water ring, featuring a bubbly flow, in the vaneless gap of a reduced scale physical model of a pump-turbine operating in dewatered condition is investigated. High speed visualizations are performed together with pressure fluctuation measu ...

2018

Air-Water Ring in the Vaneless Gap of a Reversible Pump-Turbine Operating in Condenser Mode

François Avellan, Elena Vagnoni, Loïc Andolfatto, Pierre Leroy

2018

Two-phase flow phenomena in hydraulic turbines and pump-turbines operating in synchronous condenser mode

Elena Vagnoni

Hydraulic turbines and pump-turbines are often required to operate in particular conditions at which they consume active power. To keep the power consumption at a minimum, it is necessary to dewater the runner to reduce the mechanical torque. One of these ...

EPFL2018

Experimental investigation of the sloshing motion of the water free surface in the draft tube of a Francis turbine operating in synchronous condenser mode

François Avellan, Arthur Tristan Favrel, Elena Vagnoni, Loïc Andolfatto

Hydropower units may be required to operate in condenser mode to supply reactive power. In this operating mode, the water level in the turbine or pump-turbine is decreased below the runner by closing the guide vanes and injecting pressurized air. While ope ...

2018

On the sloshing free surface in the draft tube cone of a Francis turbine operating in synchronous condenser mode

François Avellan, Elena Vagnoni, Loïc Andolfatto

Hydropower plants may be required to operate in synchronous condenser mode in order to supply reactive power to the grid for compensating the fluctuations introduced by the intermittent renewable energies such wind and solar. When operating in this mode, t ...

2017

Simulation of energy recovery on water utility networks by a micro-turbine with counter-rotating runners

François Avellan, Cécile Münch-Alligné, Vlad Hasmatuchi, Elena Vagnoni, Loïc Andolfatto

Wherever relief valves and other energy dissipation devices are installed to limit the pressure, water utility networks provide unexploited hydropower potentials. This is mainly due to a lack of economically viable technologies for energy recovery in the p ...

International Association For Hydraulic Research2016

A mixed standard/custom design strategy to minimize cost and maximize efficiency for picohydro power potential harvesting

François Avellan, Cécile Münch-Alligné, Elena Vagnoni, Loïc Andolfatto

Harvesting the numerous small scale hydroelectric potential is a way to increase the sustainable hydraulic energy production in developed countries. The condition to meet economical profitability with pico power stations - below 25 kW - is to minimize the ...

2015

Analytical hill chart towards the maximisation of energy recovery on water utility networks with counter rotating micro-turbine

François Avellan, Cécile Münch-Alligné, Elena Vagnoni, Loïc Andolfatto, João Nuno Gomes Borga Delgado

Existing water utility networks provides a wide, distributed and unexploited hydropower potential. The installation of energy recovery stations on existing infrastructures limits both the required investment and the environmental impact. The counter-rotati ...

2015

Experimental evaluation of the velocity profiles and performance of a counter rotating micro-turbine by 2D laser Doppler velocimetry

François Avellan, Cécile Münch-Alligné, Elena Vagnoni, Loïc Andolfatto

The most exploited renewable energy at a global scale is hydropower, which nowadays accounts for the 18 % of the world’s electricity supply. Its production is expected to increase approximately 3.1% each year in the next 25 years maintaining its share in t ...

2015

Application of Laser Doppler Velocimetry to the development of a counter rotating micro-turbine

François Avellan, Cécile Münch-Alligné, Elena Vagnoni, Loïc Andolfatto, João Nuno Gomes Borga Delgado

The sustainability of the electricity mix can be increased by introducing recovery energy systems on existing water supply infrastructures. The concept of the new counter rotating micro-turbine presented in this work is a competitive option for energy reco ...

2015

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