2019
Mao, Xiuli; Pavesi, Giorgio; Chen, Diyi; Xu, Hengshan; Mao, Gaojun
Flow induced noise characterization of pump turbine in continuous and intermittent load rejection processes Journal Article
In: Renewable Energy, vol. 139, pp. 1029-1039, 2019, ISSN: 18790682.
Abstract | Links | BibTeX | Tags: Flow induced noise, Hydroelectric energy, Load rejection, Pressure fluctuations, Pump as Turbine
@article{Mao2019a,
title = {Flow induced noise characterization of pump turbine in continuous and intermittent load rejection processes},
author = {Xiuli Mao and Giorgio Pavesi and Diyi Chen and Hengshan Xu and Gaojun Mao},
url = {https://doi.org/10.1016/j.renene.2019.02.116},
doi = {10.1016/j.renene.2019.02.116},
issn = {18790682},
year = {2019},
date = {2019-01-01},
journal = {Renewable Energy},
volume = {139},
pages = {1029-1039},
publisher = {Elsevier Ltd},
abstract = {In order to study pump turbine stability in view of flow induced noise, this paper focuses on two-part operation of one high head reversible turbine: transient load rejection process and intermittent vane closing conditions. Both above simulations are solved by DES turbulent model, additionally, the flow field results are regarded as sound source and analyzed comparatively by LMS software. Except for flow field interpretation, some developing rules of flow induced noise during the period of pump turbine load rejection are found. The result indicates that flow induced noise radiation is consistent with internal fluid characteristics, and the developing trends are similar which acquired from these two part calculations, whereas the values are distinct. This work provides a reference for the study of pump turbine operating stability from the acoustic aspect, and for pump turbine design work as well.},
keywords = {Flow induced noise, Hydroelectric energy, Load rejection, Pressure fluctuations, Pump as Turbine},
pubstate = {published},
tppubtype = {article}
}
In order to study pump turbine stability in view of flow induced noise, this paper focuses on two-part operation of one high head reversible turbine: transient load rejection process and intermittent vane closing conditions. Both above simulations are solved by DES turbulent model, additionally, the flow field results are regarded as sound source and analyzed comparatively by LMS software. Except for flow field interpretation, some developing rules of flow induced noise during the period of pump turbine load rejection are found. The result indicates that flow induced noise radiation is consistent with internal fluid characteristics, and the developing trends are similar which acquired from these two part calculations, whereas the values are distinct. This work provides a reference for the study of pump turbine operating stability from the acoustic aspect, and for pump turbine design work as well.
2018
Xiuli, Mao; Giorgio, Pavesi; Yuan, Zheng
Francis-Type reversible turbine field investigation during fast closure of wicket gates Journal Article
In: Journal of Fluids Engineering, Transactions of the ASME, vol. 140, iss. 6, pp. 061103, 2018, ISSN: 00982202.
Abstract | Links | BibTeX | Tags: Dynamic Mesh, Francis-type Reversible Turbine, Load rejection, transient flow
@article{Xiuli2018a,
title = {Francis-Type reversible turbine field investigation during fast closure of wicket gates},
author = {Mao Xiuli and Pavesi Giorgio and Zheng Yuan},
doi = {10.1115/1.4039089},
issn = {00982202},
year = {2018},
date = {2018-01-01},
journal = {Journal of Fluids Engineering, Transactions of the ASME},
volume = {140},
issue = {6},
pages = {061103},
abstract = {Flexible electricity demand and variability of the electricity produced by wind turbines and photovoltaic affect the stable operations of power grids. Pump-Turbines are used to stabilize the power grid by maintaining a real-Time electricity demand. Consistently, the machines experience transient conditions during the course of operation, such as startup, load acceptance, load rejection, and shutdown, which induce high amplitude pressure pulsations and affect operating lifespan of the components. During the closure of the wicket gates, the transient flow characteristics is analyzed for a Francis-Type reversible pump-Turbine in generating mode by three-dimensional (3D) numerical simulation with a moving mesh technique and using detached eddy simulation (DES) turbulent model. Mesh motion is carried out in the region of wicket gates during the load rejection by a moving, sliding mesh, which makes dynamic flow simulation available, instead of building various steady models with different guide vanes angles. The transient flow characteristics are illustrated by analyzing the flow, torque, and pressure fluctuations signals by frequency and time-frequency analyses. The flow field analysis includes the onset and strengthening of unsteady phenomena during the turbine load reduction. The flow pattern in return channel maintained a quite stable flow field, whereas the flow pattern in the runner and draft tube emphasized its instability with the flow rate decreased. Influence of 3D unsteady flow structures on runner is determined, and its evolution is characterized spectrally during fast closure of wicket gates. © 2018 by ASME.},
keywords = {Dynamic Mesh, Francis-type Reversible Turbine, Load rejection, transient flow},
pubstate = {published},
tppubtype = {article}
}
Flexible electricity demand and variability of the electricity produced by wind turbines and photovoltaic affect the stable operations of power grids. Pump-Turbines are used to stabilize the power grid by maintaining a real-Time electricity demand. Consistently, the machines experience transient conditions during the course of operation, such as startup, load acceptance, load rejection, and shutdown, which induce high amplitude pressure pulsations and affect operating lifespan of the components. During the closure of the wicket gates, the transient flow characteristics is analyzed for a Francis-Type reversible pump-Turbine in generating mode by three-dimensional (3D) numerical simulation with a moving mesh technique and using detached eddy simulation (DES) turbulent model. Mesh motion is carried out in the region of wicket gates during the load rejection by a moving, sliding mesh, which makes dynamic flow simulation available, instead of building various steady models with different guide vanes angles. The transient flow characteristics are illustrated by analyzing the flow, torque, and pressure fluctuations signals by frequency and time-frequency analyses. The flow field analysis includes the onset and strengthening of unsteady phenomena during the turbine load reduction. The flow pattern in return channel maintained a quite stable flow field, whereas the flow pattern in the runner and draft tube emphasized its instability with the flow rate decreased. Influence of 3D unsteady flow structures on runner is determined, and its evolution is characterized spectrally during fast closure of wicket gates. © 2018 by ASME.
