2020
Wang, Wenjie; Pavesi, Giorgio; Pei, Ji; Yuan, Shouqi
Transient simulation on closure of wicket gates in a high-head Francis-type reversible turbine operating in pump mode Journal Article
In: Renewable Energy, vol. 145, pp. 1817-1830, 2020, ISSN: 09601481.
Abstract | Links | BibTeX | Tags: Closure of Wicket Gate, Dynamic Mesh, Energy storage, Francis-type Reversible Turbine, PHES, power reduction scenario, Pumped-hydro energy storage plant, transient flow
@article{Wang2020,
title = {Transient simulation on closure of wicket gates in a high-head Francis-type reversible turbine operating in pump mode},
author = {Wenjie Wang and Giorgio Pavesi and Ji Pei and Shouqi Yuan},
url = {https://doi.org/10.1016/j.renene.2019.07.052},
doi = {10.1016/j.renene.2019.07.052},
issn = {09601481},
year = {2020},
date = {2020-01-01},
journal = {Renewable Energy},
volume = {145},
pages = {1817-1830},
abstract = {To solve the problem of grid instabilities, regulation in the Pumped Hydro Energy Storage (PHES) plants should quickly respond to the variation of electricity produced by unpredictable renewable energy. In this paper, a power reduction scenario applied to a pump turbine of a PHES is simulated considering the transient closure process of wicket gate. A novel dynamic mesh technique is applied to simulate the rotation of wicket gate vanes from best efficiency point to shutdown condition. Detached Eddy Simulation (DES) turbulence model is utilized to capture complex unsteady flow and the water weak compressibility effect is considered in the transient simulation. Flow rate, torque, power and pressure are analysed by the Fast Fourier Transform (FFT) and Continuous Wavelet Transform (CWT) methods. The results illustrate the delay between the performance parameters flow rate and power and the wicket gate opening angle. The closure of wicket gates affects the flow characteristics downstream the wicket gates greatly, causing intensive pressure fluctuations. The magnitude of pressure fluctuations downstream the wicket gate becomes the highest with the wicket gate closure of about 60%. Aside the blade passage frequency, a low frequency occurs, with the appearance of unsteady flow in pump turbine. Moreover, strong torque pulsations occur on the pin of the wicket vane when the percentage of closure is between 60% and 80%, with peaks much higher than that at the best efficiency point. The transient results can provide meaningful reference to the regulation law of wicket gate for safe operation of the pump turbine.},
keywords = {Closure of Wicket Gate, Dynamic Mesh, Energy storage, Francis-type Reversible Turbine, PHES, power reduction scenario, Pumped-hydro energy storage plant, transient flow},
pubstate = {published},
tppubtype = {article}
}
To solve the problem of grid instabilities, regulation in the Pumped Hydro Energy Storage (PHES) plants should quickly respond to the variation of electricity produced by unpredictable renewable energy. In this paper, a power reduction scenario applied to a pump turbine of a PHES is simulated considering the transient closure process of wicket gate. A novel dynamic mesh technique is applied to simulate the rotation of wicket gate vanes from best efficiency point to shutdown condition. Detached Eddy Simulation (DES) turbulence model is utilized to capture complex unsteady flow and the water weak compressibility effect is considered in the transient simulation. Flow rate, torque, power and pressure are analysed by the Fast Fourier Transform (FFT) and Continuous Wavelet Transform (CWT) methods. The results illustrate the delay between the performance parameters flow rate and power and the wicket gate opening angle. The closure of wicket gates affects the flow characteristics downstream the wicket gates greatly, causing intensive pressure fluctuations. The magnitude of pressure fluctuations downstream the wicket gate becomes the highest with the wicket gate closure of about 60%. Aside the blade passage frequency, a low frequency occurs, with the appearance of unsteady flow in pump turbine. Moreover, strong torque pulsations occur on the pin of the wicket vane when the percentage of closure is between 60% and 80%, with peaks much higher than that at the best efficiency point. The transient results can provide meaningful reference to the regulation law of wicket gate for safe operation of the pump turbine.
2014
Ardizzon, Guido; Cavazzini, Giovanna; Pavesi, Giorgio
A new generation of small hydro and pumped-hydro power plants: Advances and future challenges Journal Article
In: Renewable and Sustainable Energy Reviews, vol. 31, pp. 746-761, 2014, ISSN: 13640321.
Abstract | Links | BibTeX | Tags: CFD, Hydropower, Optimal management strategies, Pumped-hydro energy storage plant, Small hydro power plant, Variable-speed pump-turbine
@article{Ardizzon2014a,
title = {A new generation of small hydro and pumped-hydro power plants: Advances and future challenges},
author = {Guido Ardizzon and Giovanna Cavazzini and Giorgio Pavesi},
url = {http://linkinghub.elsevier.com/retrieve/pii/S1364032113008575},
doi = {10.1016/j.rser.2013.12.043},
issn = {13640321},
year = {2014},
date = {2014-01-01},
journal = {Renewable and Sustainable Energy Reviews},
volume = {31},
pages = {746-761},
abstract = {Hydropower is not only a renewable and sustainable energy source, but its flexibility and storage capacity also makes it possible to improve grid stability and to support the deployment of other intermittent renewable energy sources such as wind and solar power. As a result, a renewed interest in pumped-hydro energy storage plants (PHES) and a huge demand for the rehabilitation of old small hydropower plants are emerging globally. As regards PHES, advances in turbine design are required to increase plant performance and flexibility and new strategies for optimizing storage capacity and for maximizing plant profitability in the deregulated energy market have to be developed. During the upgrading of old small hydropower plants, the main challenges to be faced are the design of new runners, that had to match the existing stationary parts, and the development of optimal sizing and management strategies to increase their economic appeal. This paper traces an overview of the prospects of pumped-hydro energy storage plants and small hydro power plants in the light of sustainable development. Advances and future challenges in both turbine design and plant planning and management are proposed. PHES and hybrid wind/solar-PHES are illustrated and discussed, as well as the limits and peculiarities of the new design strategies, based on computational fluid dynamics, for both PHES and small hydropower plants. ?? 2014 Elsevier Ltd.},
keywords = {CFD, Hydropower, Optimal management strategies, Pumped-hydro energy storage plant, Small hydro power plant, Variable-speed pump-turbine},
pubstate = {published},
tppubtype = {article}
}
Hydropower is not only a renewable and sustainable energy source, but its flexibility and storage capacity also makes it possible to improve grid stability and to support the deployment of other intermittent renewable energy sources such as wind and solar power. As a result, a renewed interest in pumped-hydro energy storage plants (PHES) and a huge demand for the rehabilitation of old small hydropower plants are emerging globally. As regards PHES, advances in turbine design are required to increase plant performance and flexibility and new strategies for optimizing storage capacity and for maximizing plant profitability in the deregulated energy market have to be developed. During the upgrading of old small hydropower plants, the main challenges to be faced are the design of new runners, that had to match the existing stationary parts, and the development of optimal sizing and management strategies to increase their economic appeal. This paper traces an overview of the prospects of pumped-hydro energy storage plants and small hydro power plants in the light of sustainable development. Advances and future challenges in both turbine design and plant planning and management are proposed. PHES and hybrid wind/solar-PHES are illustrated and discussed, as well as the limits and peculiarities of the new design strategies, based on computational fluid dynamics, for both PHES and small hydropower plants. ?? 2014 Elsevier Ltd.
