2024
Wang, Wenjie; Qiu, Gai; Pei, Ji; Pavesi, Giorgio; Tai, Geyuan; Yuan, Shouqi
Effect of return channel on performance and pressure fluctuation of pump turbine Journal Article
In: Physics of Fluids, vol. 36, iss. 10, 2024, ISSN: 10897666.
Abstract | Links | BibTeX | Tags: Closure of Wicket Gate, Guide Vane Closure, Hydro plant control, Pumped hydro storage
@article{Wang2024,
title = {Effect of return channel on performance and pressure fluctuation of pump turbine},
author = {Wenjie Wang and Gai Qiu and Ji Pei and Giorgio Pavesi and Geyuan Tai and Shouqi Yuan},
doi = {10.1063/5.0229130},
issn = {10897666},
year = {2024},
date = {2024-01-01},
urldate = {2024-01-01},
journal = {Physics of Fluids},
volume = {36},
issue = {10},
publisher = {American Institute of Physics},
abstract = {To stabilize the operation of pumped storage power station, an orthogonal experimental design was proposed to optimize the return channel with the splitter blades of the pump turbine. The calculation results of various return channel models under multiple operating conditions indicated that inlet distance a1 and blade number z considerably affect the efficiency and flow pattern in the flow passage. The optimal scheme improved efficiency by nearly 3% at 0.6Qd. The Savitzky-Golay filtering method and Fast Fourier Transform were used to analyze the unsteady characteristics of the pump turbine in pump model. The amplitude of pressure pulsations at the blade passing frequency in the vaneless space and the interference zone between the guide vane and return channel reduced considerably, and the pressure pulsation amplitude in the vaneless zone decreased by 50%, 48%, and 20% for 0.6Qd, 1.0Qd, and 1.1Qd operating conditions. A Continuous Wavelet Transform was used to analyze frequency signals during the shutdown transition process. The optimization of the splitter blades improved the flow pattern in their corresponding flow passages and suppressed high-amplitude pressure pulsations in the unit for the stable operation of the pumped storage power station.},
keywords = {Closure of Wicket Gate, Guide Vane Closure, Hydro plant control, Pumped hydro storage},
pubstate = {published},
tppubtype = {article}
}
To stabilize the operation of pumped storage power station, an orthogonal experimental design was proposed to optimize the return channel with the splitter blades of the pump turbine. The calculation results of various return channel models under multiple operating conditions indicated that inlet distance a1 and blade number z considerably affect the efficiency and flow pattern in the flow passage. The optimal scheme improved efficiency by nearly 3% at 0.6Qd. The Savitzky-Golay filtering method and Fast Fourier Transform were used to analyze the unsteady characteristics of the pump turbine in pump model. The amplitude of pressure pulsations at the blade passing frequency in the vaneless space and the interference zone between the guide vane and return channel reduced considerably, and the pressure pulsation amplitude in the vaneless zone decreased by 50%, 48%, and 20% for 0.6Qd, 1.0Qd, and 1.1Qd operating conditions. A Continuous Wavelet Transform was used to analyze frequency signals during the shutdown transition process. The optimization of the splitter blades improved the flow pattern in their corresponding flow passages and suppressed high-amplitude pressure pulsations in the unit for the stable operation of the pumped storage power station.
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.
