Evaluating the pressure fluctuations during load rejection of two pump-turbines in a prototype pumped-storage system by using 1D-3D coupled simulation

2021 ◽  
Author(s):  
Demin Liu ◽  
Xiaoxi Zhang ◽  
Zhiyan Yang ◽  
Ke Liu ◽  
Yongguang Cheng
Keyword(s):  
Storage System ◽  
Pressure Fluctuations ◽  
Coupled Simulation ◽  
Pumped Storage

Water column separation in pump-turbine after load rejection: 1D-3D coupled simulation of a model pumped-storage system

2021 ◽  
Vol 163 ◽  
pp. 685-697
Author(s):  
Xiaoxi Zhang ◽  
Yongguang Cheng ◽  
Zhiyan Yang ◽  
Qiuhua Chen ◽  
Demin Liu
Keyword(s):  
Water Column ◽  
Storage System ◽  
Coupled Simulation ◽  
Pump Turbine ◽  
Column Separation ◽  
Pumped Storage

scholarly journals Optimal Model for Complementary Operation of a Photovoltaic-Wind-Pumped Storage System

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Jinjin Gao ◽  
Yuan Zheng ◽  
Jianming Li ◽  
Xiaoming Zhu ◽  
Kan Kan
Keyword(s):  
Wind Power ◽  
Storage System ◽  
Optimal Solution ◽  
Multiobjective Problems ◽  
Storage Station ◽  
Compromise Optimal Solution ◽  
Pumped Storage ◽  
Economic Objective ◽  
Single Objective

An optimization model for the complementary operation of a photovoltaic-wind-pumped storage system is built to make full use of solar and wind energy. Apart from ensuring the maximum economic benefit which is normally used as the only objective, the stable objectives of minimizing the output fluctuation and variation of load and output difference are added to form the multiobjective problems because of lack of study on access capacity of photovoltaic and wind power. The model aims to increase the power benefit and reduce the output fluctuation and variation of load and output difference under the constraints of station, output balance, and transmission limitation. In a case study, four schemes including single-objective independent operation, single-objective complementary operation, and multiobjective complementary operation are compared to discuss the effect of pumped storage station on economic objective and stable objectives. Furthermore, the opposite trend of the two objectives is proved and a compromise optimal solution is given. The results indicate that the pumped storage station can effectively increase power benefit and access capacity of photovoltaic and wind power. The study can provide references to the complementary optimization of the pumped storage station and the intermittent renewable energy.

Destructive Vibration of Trashracks due to Fluid-Structure Interaction

1975 ◽  
Vol 97 (4) ◽  
pp. 1359-1365 ◽  
Author(s):  
S. H. Crandall ◽  
S. Vigander ◽  
P. A. March
Keyword(s):  
Vortex Shedding ◽  
Storage System ◽  
Water Channel ◽  
Scale Model ◽  
Original Design ◽  
Cross Sectional ◽  
Flow Rates ◽  
Pumped Storage ◽  
Sectional Shape ◽  
Lock In

Trashracks in pumped storage systems with high flow rates can develop fatigue failures due to excessive vibration excited by the flow past the rods in the rack. An experimental study of trashrack vibration was made on a half-scale model of a prototype rack design for the TVA Raccoon Mountain pumped storage system. The natural frequencies and loss factors of the first dozen natural modes of the rack were determined in air before placing the rack in a water channel. Under normal flow rates the rack developed “locked-in” pure tone vibrations of sufficient amplitude to cause early fatigue failure. Unexpectedly, the frequency of the vibration was not close to the vortex-shedding frequency and the motion of the rods was not transverse to the flow. The “locked-in” modes were identified as modes in which the bending displacements of the rods were parallel to the flow. Further investigation showed that the excitation mechanism involved synchronization between the fluctuating drag involved in vortex shedding and the fore-and-aft motion of the rods in sharply resonant modes. Modifications of the original design were introduced to defeat the identified mechanism. In order to completely eliminate the “lock-in” phenomenon it was necessary to change the bar cross-sectional shape and to introduce additional damping into the rack structure. A half-scale model of the modified design was built and tested to verify the absence of destructive vibrations.

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