2017
Santolin, Alberto; Pavesi, Giorgio; Cavazzini, Giovanna; Ardizzon, Guido
Techno-economic feasibility analysis for energy production by variable speed Francis turbines in water distribution networks Proceedings Article
In: Tamanini.It, 2017.
Abstract | Links | BibTeX | Tags: Pelton Turbine, Variable-speed turbine
@inproceedings{pop00073,
title = {Techno-economic feasibility analysis for energy production by variable speed Francis turbines in water distribution networks},
author = {Alberto Santolin and Giorgio Pavesi and Giovanna Cavazzini and Guido Ardizzon},
url = {http://tamanini.it/wp/wp-content/uploads/2017/03/Techno_Economic-feasibility-analysis-for-energy-production-by-variable-speed-Francis-turbines-in-water-distribution-networks.pdf},
year = {2017},
date = {2017-01-01},
urldate = {2017-01-01},
booktitle = {Tamanini.It},
abstract = {This paper presents an Italian case study of a small hydropower plant exploiting the reserved flow (RF) at the dam outlet. The significant variations of the water level in the reservoir and of the seasonal RF discharged in accordance with the Italian environmental laws determine extremely variable operating conditions for the hydropower plant that can be efficiently faced only resorting to a variable speed turbine. This breakthrough technology allows to optimize the machine performance at a wider range of operating conditions, but still presents several issues to be faced, for example the lack of standardized design criteria. This study was focused on the design optimization of the variable-speed Pelton turbine to be installed in the small hydropower plant. Numerical analyses were carried out by the commercial code Ansys CFX 14 to define a Pelton bucket geometry characterized by high efficiency values in the requested wide operating range. , A transient homogeneous model coupled with a SST turbulence model was applied to solve the two-phase flow field., Experimental analyses were also carried out on the optimized runner in an open water test rig of the Laboratory of Turbomachinery of the University of Padova to validate the numerical simulations results. The experimental test rig, equipped with a pressurized reservoir, was properly settled so as to verify the turbine performance in a wide operating range. Finally, the results of the combined numerical and experimental design optimization were verified by comparison with the performance of the model installed in the small hydropower plant of Forte Buso.},
keywords = {Pelton Turbine, Variable-speed turbine},
pubstate = {published},
tppubtype = {inproceedings}
}
This paper presents an Italian case study of a small hydropower plant exploiting the reserved flow (RF) at the dam outlet. The significant variations of the water level in the reservoir and of the seasonal RF discharged in accordance with the Italian environmental laws determine extremely variable operating conditions for the hydropower plant that can be efficiently faced only resorting to a variable speed turbine. This breakthrough technology allows to optimize the machine performance at a wider range of operating conditions, but still presents several issues to be faced, for example the lack of standardized design criteria. This study was focused on the design optimization of the variable-speed Pelton turbine to be installed in the small hydropower plant. Numerical analyses were carried out by the commercial code Ansys CFX 14 to define a Pelton bucket geometry characterized by high efficiency values in the requested wide operating range. , A transient homogeneous model coupled with a SST turbulence model was applied to solve the two-phase flow field., Experimental analyses were also carried out on the optimized runner in an open water test rig of the Laboratory of Turbomachinery of the University of Padova to validate the numerical simulations results. The experimental test rig, equipped with a pressurized reservoir, was properly settled so as to verify the turbine performance in a wide operating range. Finally, the results of the combined numerical and experimental design optimization were verified by comparison with the performance of the model installed in the small hydropower plant of Forte Buso.
2013
Pavesi, Giorgio; Rossetti, Antonio; Santolin, Alberto; Ardizzon, Guido
Numerical Analyses of a Cavitating Pelton Turbine Proceedings Article
In: 10th European Conference on Turbomachinery Fluid Dynamics and Thermodynamics, ETC 2013, pp. 1-12, 2013, ISSN: 24104833.
Abstract | BibTeX | Tags: Cavitation, CFD, Pelton Turbine
@inproceedings{Pavesi2013,
title = {Numerical Analyses of a Cavitating Pelton Turbine},
author = {Giorgio Pavesi and Antonio Rossetti and Alberto Santolin and Guido Ardizzon},
issn = {24104833},
year = {2013},
date = {2013-01-01},
urldate = {2013-01-01},
booktitle = {10th European Conference on Turbomachinery Fluid Dynamics and Thermodynamics, ETC 2013},
pages = {1-12},
abstract = {Erosive wear of hydro turbine runners is a complex phenomenon, which depends upon many parameters and which leads to a decrease of the performance in time and/or in extreme cases to the rotor mechanical failure. Consistently, the study of this wearing process is an important step to improve the impeller design, to avoid or minimize the rise of extraordinary maintenance. In the present paper the cavitation mechanics of a Pelton turbine was investigated using CFD analyses. A Pelton affected by pitting cavitation was taken as test case. The Pelton geometry was modelled and analyzed using unsteady Reynolds averaged Navier-Stokes (RANS) multiphase analyses. The homogeneous approach was used to describe the multiphase flow composed by water, water vapour and air. Numerical results discriminated the vapour production processes during the cut in of the bucket on the water jet. The design and the part load flow rates were analyzed and the cavitation process compared. A simple procedure to identify the locations of higher damage risk was presented and verified on the test case runner.},
keywords = {Cavitation, CFD, Pelton Turbine},
pubstate = {published},
tppubtype = {inproceedings}
}
Erosive wear of hydro turbine runners is a complex phenomenon, which depends upon many parameters and which leads to a decrease of the performance in time and/or in extreme cases to the rotor mechanical failure. Consistently, the study of this wearing process is an important step to improve the impeller design, to avoid or minimize the rise of extraordinary maintenance. In the present paper the cavitation mechanics of a Pelton turbine was investigated using CFD analyses. A Pelton affected by pitting cavitation was taken as test case. The Pelton geometry was modelled and analyzed using unsteady Reynolds averaged Navier-Stokes (RANS) multiphase analyses. The homogeneous approach was used to describe the multiphase flow composed by water, water vapour and air. Numerical results discriminated the vapour production processes during the cut in of the bucket on the water jet. The design and the part load flow rates were analyzed and the cavitation process compared. A simple procedure to identify the locations of higher damage risk was presented and verified on the test case runner.
Rossetti, Antonio; Pavesi, Giorgio; Cavazzini, Giovanna; Santolin, Alberto; Ardizzon, Guido
Influence of the bucket geometry on the Pelton performance Journal Article
In: Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy, vol. 228, iss. 1, pp. 33-45, 2013, ISSN: 0957-6509.
Abstract | Links | BibTeX | Tags: Bucket Geometry, Eulerian-Lagrangian method, Hydraulic Turbines, hydro power, Pelton Turbine, Performance Analysis, Turbine Design
@article{Rossetti2013a,
title = {Influence of the bucket geometry on the Pelton performance},
author = {Antonio Rossetti and Giorgio Pavesi and Giovanna Cavazzini and Alberto Santolin and Guido Ardizzon},
url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84899444882&partnerID=tZOtx3y1},
doi = {10.1177/0957650913506589},
issn = {0957-6509},
year = {2013},
date = {2013-01-01},
urldate = {2013-01-01},
journal = {Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy},
volume = {228},
issue = {1},
pages = {33-45},
publisher = {Professional Engineering Publishing},
abstract = {The increasing share of hydropower in world electricity production requires the development of standardized and optimized design procedures leading to increasingly higher efficiency values.To date, despite a certain amount of support from computational fluid dynamics, Pelton turbines are still characterized by semiempirical design criteria that do not make it possible to optimize the jet-bucket interaction in order to maximize turbine performance. Based on an analysis of particle flow tracks, this paper presents a hybrid Eulerian-Lagrangian method to investigate the influence of bucket geometry on the Pelton efficiency at two different operating conditions. Jet-bucket interaction was numerically analyzed by means of a traditional mesh-based numerical approach, using a transient multi-phase homogeneous model. Subsequently, the numerical results were integrated using a predictor-corrector algorithm, combining a fourth order Adams-Bashforth method as predictor and a fourth order Adams-Moulton method as corrector, in order to determine the fluid particle trajectories on the rotating buckets. The particle flow tracks were analyzed in detail to evaluate the single-particle performance in terms of discharged kinetic energy, momentum variation, and total energy variation during the jet-bucket interaction. Moreover, on the basis of the particle discharging position, the contribution of the different bucket areas to the total torque of the turbine was investigated to determine the time-depending influence of the bucket geometry on the turbine energy exchange and to suggest possible design solutions for improving bucket performance. © IMechE 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.},
keywords = {Bucket Geometry, Eulerian-Lagrangian method, Hydraulic Turbines, hydro power, Pelton Turbine, Performance Analysis, Turbine Design},
pubstate = {published},
tppubtype = {article}
}
The increasing share of hydropower in world electricity production requires the development of standardized and optimized design procedures leading to increasingly higher efficiency values.To date, despite a certain amount of support from computational fluid dynamics, Pelton turbines are still characterized by semiempirical design criteria that do not make it possible to optimize the jet-bucket interaction in order to maximize turbine performance. Based on an analysis of particle flow tracks, this paper presents a hybrid Eulerian-Lagrangian method to investigate the influence of bucket geometry on the Pelton efficiency at two different operating conditions. Jet-bucket interaction was numerically analyzed by means of a traditional mesh-based numerical approach, using a transient multi-phase homogeneous model. Subsequently, the numerical results were integrated using a predictor-corrector algorithm, combining a fourth order Adams-Bashforth method as predictor and a fourth order Adams-Moulton method as corrector, in order to determine the fluid particle trajectories on the rotating buckets. The particle flow tracks were analyzed in detail to evaluate the single-particle performance in terms of discharged kinetic energy, momentum variation, and total energy variation during the jet-bucket interaction. Moreover, on the basis of the particle discharging position, the contribution of the different bucket areas to the total torque of the turbine was investigated to determine the time-depending influence of the bucket geometry on the turbine energy exchange and to suggest possible design solutions for improving bucket performance. © IMechE 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.
Santolin, Alberto; Pavesi, Giorgio; Cavazzini, Giovanna; Ardizzon, Guido
Variable-speed Pelton turbine for an efficient exploitation of the reserved flow: an Italian case study Proceedings Article
In: HYDRO 2013 - Promoting the Versatile Role of Hydro, 2013.
Abstract | BibTeX | Tags: Pelton Turbine, Variable Speed
@inproceedings{Santolin2013,
title = {Variable-speed Pelton turbine for an efficient exploitation of the reserved flow: an Italian case study},
author = {Alberto Santolin and Giorgio Pavesi and Giovanna Cavazzini and Guido Ardizzon},
year = {2013},
date = {2013-01-01},
urldate = {2013-01-01},
booktitle = {HYDRO 2013 - Promoting the Versatile Role of Hydro},
abstract = {This paper presents an Italian case study of a small hydropower plant exploiting the reserved flow (RF) at the dam outlet. The significant variations of the water level in the reservoir and of the seasonal RF discharged in accordance with the Italian environmental laws determine extremely variable operating conditions for the hydropower plant that can be efficiently faced only resorting to a variable speed turbine. This breakthrough technology allows to optimize the machine performance at a wider range of operating conditions, but still presents several issues to be faced, for example the lack of standardized design criteria. This study was focused on the design optimization of the variable-speed Pelton turbine to be installed in the small hydropower plant. Numerical analyses were carried out by the commercial code Ansys CFX 14 to define a Pelton bucket geometry characterized by high efficiency values in the requested wide operating range. , A transient homogeneous model coupled with a SST turbulence model was applied to solve the two-phase flow field., Experimental analyses were also carried out on the optimized runner in an open water test rig of the Laboratory of Turbomachinery of the University of Padova to validate the numerical simulations results. The experimental test rig, equipped with a pressurized reservoir, was properly settled so as to verify the turbine performance in a wide operating range. Finally, the results of the combined numerical and experimental design optimization were verified by comparison with the performance of the model installed in the small hydropower plant of Forte Buso.},
keywords = {Pelton Turbine, Variable Speed},
pubstate = {published},
tppubtype = {inproceedings}
}
This paper presents an Italian case study of a small hydropower plant exploiting the reserved flow (RF) at the dam outlet. The significant variations of the water level in the reservoir and of the seasonal RF discharged in accordance with the Italian environmental laws determine extremely variable operating conditions for the hydropower plant that can be efficiently faced only resorting to a variable speed turbine. This breakthrough technology allows to optimize the machine performance at a wider range of operating conditions, but still presents several issues to be faced, for example the lack of standardized design criteria. This study was focused on the design optimization of the variable-speed Pelton turbine to be installed in the small hydropower plant. Numerical analyses were carried out by the commercial code Ansys CFX 14 to define a Pelton bucket geometry characterized by high efficiency values in the requested wide operating range. , A transient homogeneous model coupled with a SST turbulence model was applied to solve the two-phase flow field., Experimental analyses were also carried out on the optimized runner in an open water test rig of the Laboratory of Turbomachinery of the University of Padova to validate the numerical simulations results. The experimental test rig, equipped with a pressurized reservoir, was properly settled so as to verify the turbine performance in a wide operating range. Finally, the results of the combined numerical and experimental design optimization were verified by comparison with the performance of the model installed in the small hydropower plant of Forte Buso.
2011
Santolin, Alberto; Cavazzini, Giovanna; Pavesi, Giorgio
Effect of penstock length variation on hydraulic transients Journal Article
In: Energy Conversion and …, 2011.
Links | BibTeX | Tags: Pelton, Pelton Turbine
@article{pop00065,
title = {Effect of penstock length variation on hydraulic transients},
author = {Alberto Santolin and Giovanna Cavazzini and Giorgio Pavesi},
url = {http://www.indianjournals.com/ijor.aspx?target=ijor:tidee&volume=10&issue=2&article=013&type=pdf},
year = {2011},
date = {2011-01-01},
urldate = {2011-01-01},
journal = {Energy Conversion and …},
publisher = {indianjournals.com},
keywords = {Pelton, Pelton Turbine},
pubstate = {published},
tppubtype = {article}
}
2009
Santolin, Alberto; Cavazzini, Giovanna; Ardizzon, Guido; Pavesi, Giorgio
Numerical investigation of the interaction between jet and bucket in a Pelton turbine Proceedings Article
In: Manna, Marcello; Scrivener, Colin; Martelli, Francesco (Ed.): Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy, pp. 721-728, journals.sagepub.com, 2009, ISSN: 09576509, (<b>From Duplicate 1 (<i>Numerical investigation of the interaction between jet and bucket in a Pelton turbine</i> - Santolin, A.; Cavazzini, G.; Ardizzon, G.; Pavesi, G.; ...; Pavesi, G.)<br/></b><br/><b>From Duplicate 2 (<i>Numerical investigation of the interaction between jet and bucket in a Pelton turbine</i> - Santolin, A.; Cavazzini, G.; Ardizzon, G.; Pavesi, G.; ...; Pavesi, G.)<br/></b><br/><b>From Duplicate 2 (<i>Numerical investigation of the interaction between jet and bucket in a Pelton turbine</i> - Santolin, A.; Cavazzini, G.; Ardizzon, G.; Pavesi, G.; ...; Pavesi, G.)<br/></b><br/><b>From Duplicate 2 (<i>Numerical investigation of the interaction between jet and bucket in a Pelton turbine</i> - Santolin, A.; Cavazzini, G.; Ardizzon, G.; Pavesi, G.; ...; Pavesi, G.)<br/></b><br/><b>From Duplicate 3 (<i>Numerical investigation of the interaction between jet and bucket in a Pelton turbine</i> - Santolin, A; Cavazzini, G; Ardizzon, G; ...)<br/></b><br/>Query date: 2017-05-06<br/><br/><b>From Duplicate 2 (<i>Numerical investigation of the interaction between jet and bucket in a Pelton turbine</i> - Santolin, Alberto; Cavazzini, Giovanna; Ardizzon, Guido; Pavesi, Giorgio; ...; Pavesi, Giorgio)<br/></b><br/><b>From Duplicate 3 (<i>Numerical investigation of the interaction between jet and bucket in a Pelton turbine</i> - Santolin, A.; Cavazzini, G.; Ardizzon, G.; Pavesi, G.; ...; Pavesi, G.)<br/>And Duplicate 4 (<i>Numerical investigation of the interaction between jet and bucket in a Pelton turbine</i> - Santolin, A.; Cavazzini, G.; Ardizzon, G.; Pavesi, G.; ...; Pavesi, G.)<br/>And Duplicate 6 (<i>Numerical investigation of the interaction between jet and bucket in a Pelton turbine</i> - Santolin, A.; Cavazzini, G.; Ardizzon, G.; Pavesi, G.; ...; Pavesi, G.)<br/></b><br/><b>From Duplicate 2 (<i>Numerical investigation of the interaction between jet and bucket in a Pelton turbine</i> - Santolin, A.; Cavazzini, G.; Ardizzon, G.; Pavesi, G.; ...; Pavesi, G.)<br/></b><br/><b>From Duplicate 3 (<i>Numerical investigation of the interaction between jet and bucket in a Pelton turbine</i> - Santolin, A; Cavazzini, G; Ardizzon, G; ...)<br/></b><br/>Query date: 2017-05-06).
Abstract | Links | BibTeX | Tags: Hydraulic efficiency, Hydraulic power, Ideal jet, Leakage flow, Pelton Turbine, Real jet
@inproceedings{pop00033,
title = {Numerical investigation of the interaction between jet and bucket in a Pelton turbine},
author = {Alberto Santolin and Giovanna Cavazzini and Guido Ardizzon and Giorgio Pavesi},
editor = {Marcello Manna and Colin Scrivener and Francesco Martelli},
url = {http://journals.sagepub.com/doi/abs/10.1243/09576509jpe824 http://journals.sagepub.com/doi/10.1243/09576509JPE824},
doi = {10.1243/09576509JPE824},
issn = {09576509},
year = {2009},
date = {2009-01-01},
urldate = {2009-01-01},
booktitle = {Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy},
volume = {223},
issue = {6},
pages = {721-728},
publisher = {journals.sagepub.com},
abstract = {This paper presents the numerical investigation of the interaction between the jet and the bucket in a Pelton Turbine. Unsteady numerical analyses were carried out on a single jet Pelton Turbine installed in the north of Italy. A two-phase inhomogeneous model was used. Two different jet configurations were analyzed and compared. In the first configuration the interaction between the runner and an axial-symmetric jet characterized by a given velocity jet profile was investigated, whereas in the second configuration the runner was coupled with the needle nozzle and the final part of the penstock and the interaction between the jet and the bucket was analyzed. A detailed analysis of the torque highlighted the influence of the shape of the water jet on the turbine losses and the influence of the stator on the efficiency of this type of hydraulic machines was shown. The numerical results were compared with the experimental data derived from the installation test of the turbine in order to validate the numerical analysis.},
note = {<b>From Duplicate 1 (<i>Numerical investigation of the interaction between jet and bucket in a Pelton turbine</i> - Santolin, A.; Cavazzini, G.; Ardizzon, G.; Pavesi, G.; ...; Pavesi, G.)<br/></b><br/><b>From Duplicate 2 (<i>Numerical investigation of the interaction between jet and bucket in a Pelton turbine</i> - Santolin, A.; Cavazzini, G.; Ardizzon, G.; Pavesi, G.; ...; Pavesi, G.)<br/></b><br/><b>From Duplicate 2 (<i>Numerical investigation of the interaction between jet and bucket in a Pelton turbine</i> - Santolin, A.; Cavazzini, G.; Ardizzon, G.; Pavesi, G.; ...; Pavesi, G.)<br/></b><br/><b>From Duplicate 2 (<i>Numerical investigation of the interaction between jet and bucket in a Pelton turbine</i> - Santolin, A.; Cavazzini, G.; Ardizzon, G.; Pavesi, G.; ...; Pavesi, G.)<br/></b><br/><b>From Duplicate 3 (<i>Numerical investigation of the interaction between jet and bucket in a Pelton turbine</i> - Santolin, A; Cavazzini, G; Ardizzon, G; ...)<br/></b><br/>Query date: 2017-05-06<br/><br/><b>From Duplicate 2 (<i>Numerical investigation of the interaction between jet and bucket in a Pelton turbine</i> - Santolin, Alberto; Cavazzini, Giovanna; Ardizzon, Guido; Pavesi, Giorgio; ...; Pavesi, Giorgio)<br/></b><br/><b>From Duplicate 3 (<i>Numerical investigation of the interaction between jet and bucket in a Pelton turbine</i> - Santolin, A.; Cavazzini, G.; Ardizzon, G.; Pavesi, G.; ...; Pavesi, G.)<br/>And Duplicate 4 (<i>Numerical investigation of the interaction between jet and bucket in a Pelton turbine</i> - Santolin, A.; Cavazzini, G.; Ardizzon, G.; Pavesi, G.; ...; Pavesi, G.)<br/>And Duplicate 6 (<i>Numerical investigation of the interaction between jet and bucket in a Pelton turbine</i> - Santolin, A.; Cavazzini, G.; Ardizzon, G.; Pavesi, G.; ...; Pavesi, G.)<br/></b><br/><b>From Duplicate 2 (<i>Numerical investigation of the interaction between jet and bucket in a Pelton turbine</i> - Santolin, A.; Cavazzini, G.; Ardizzon, G.; Pavesi, G.; ...; Pavesi, G.)<br/></b><br/><b>From Duplicate 3 (<i>Numerical investigation of the interaction between jet and bucket in a Pelton turbine</i> - Santolin, A; Cavazzini, G; Ardizzon, G; ...)<br/></b><br/>Query date: 2017-05-06},
keywords = {Hydraulic efficiency, Hydraulic power, Ideal jet, Leakage flow, Pelton Turbine, Real jet},
pubstate = {published},
tppubtype = {inproceedings}
}
This paper presents the numerical investigation of the interaction between the jet and the bucket in a Pelton Turbine. Unsteady numerical analyses were carried out on a single jet Pelton Turbine installed in the north of Italy. A two-phase inhomogeneous model was used. Two different jet configurations were analyzed and compared. In the first configuration the interaction between the runner and an axial-symmetric jet characterized by a given velocity jet profile was investigated, whereas in the second configuration the runner was coupled with the needle nozzle and the final part of the penstock and the interaction between the jet and the bucket was analyzed. A detailed analysis of the torque highlighted the influence of the shape of the water jet on the turbine losses and the influence of the stator on the efficiency of this type of hydraulic machines was shown. The numerical results were compared with the experimental data derived from the installation test of the turbine in order to validate the numerical analysis.
