scholarly journals Study on dynamic stress of pump turbine runner during power failure in pump mode

2021 ◽  
Vol 1985 (1) ◽  
pp. 012044
Author(s):  
Kai Lin ◽  
Funan Chen ◽  
Chao Wang ◽  
Huili Bi ◽  
Yongyao Luo ◽  
...  
Keyword(s):  
Dynamic Stress ◽  
Pump Mode ◽  
Pump Turbine ◽  
Power Failure ◽  
Turbine Runner

Evaluation of gap influence on the dynamic response behavior of pump-turbine runner

2019 ◽  
Vol 36 (2) ◽  
pp. 491-508 ◽  
Author(s):  
Lingyan He ◽  
Lingjiu Zhou ◽  
Soo-Hwang Ahn ◽  
Zhengwei Wang ◽  
Yusuke Nakahara ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Dynamic Stress ◽  
Resonance Curve ◽  
Added Mass ◽  
Resonance Phenomenon ◽  
Gap Size ◽  
Pump Turbine ◽  
Content Type ◽  
Turbine Runner ◽  
Fluid Added Mass

Purpose The gaps between runner and nearby structures play an important role in the dynamic response of runner, especially for pump-turbines. This paper aims to evaluate the gap influence on the added mass and dynamic stress of pump-turbine runner and provide an improved method to predict the resonance of runner. Design/methodology/approach Acoustic-structural coupling method was used to evaluate the added mass factors of a reduced scale pump-turbine with different axial and radial gap size between runner and nearby rigid walls. Improved one-way fluid-structural interaction (FSI) simulation was used to calculate the dynamic stress of the runner, which takes into account fluid added mass effect. The time-dependent hydraulic forces on the runner surfaces that were obtained from unsteady CFD simulation were transferred to the runner structure as a boundary condition, by using mesh-matching algorithm at the FSI surfaces. Findings The results show that the added mass factors increase as the gap size decreases. The axial gaps have greater influence on the added mass factors for the in-phase (IP) modes than the counter-phase (CP) and crown-dominant (CD) modes, while the CP and CD modes are very sensitive to the radial gaps. The largest added mass factor is observed in (2 + 4)ND-CP mode (resonance mode). The results reveal that the transient structural dynamic stress analysis, with the consideration of gaps and fluid added mass, can accurately predict the resonance phenomenon. Resonance curve of the pump-turbine has been obtained which agrees well with the test result. The gap fluid has great influence on the resonance condition, while for non-resonance operating points, the effect of gaps on the dynamic stress amplitude is quite small. Originality/value This paper provides an accurate method to analyze the dynamic response during runner design stage for safety assessment. The resonance curve prediction has more significance than previous methods which predict the resonance of runner by modal or harmonic analysis.

Analysis of Francis Pump-Turbine Runner Cavitation Flows in Pump Mode

2009 ◽  
Author(s):  
Lanjin Zhang ◽  
Xingying Jing ◽  
Zhengwei Wang ◽  
Jinshi Chang ◽  
Guangjie Peng
Keyword(s):  
Suction Side ◽  
Hydraulic Performance ◽  
Pressure Side ◽  
Cavitation Flow ◽  
Pump Mode ◽  
Pump Turbine ◽  
Cavitation Performance ◽  
Turbine Runner ◽  
Turbine Mode ◽  
Better Than

Pump-turbine works in pump and turbine modes, and its hydraulic performance in pump mode is more important than that in turbine mode. The cavitation is an important factor influencing hydraulic performance in pump, especially when designing the runner. The paper studies pump cavitation flow of model pump-turbine runner and its cavitation performance. That can be a method to help design and chose pump-turbine runner. The hydraulic performance and cavitation is analyzed in different net positive suction head (NPSH) and discharge. The result shows that NPSH simulated by cavitation flow is better than that simulated by no cavitation flow. The simulation result also shows that cavitation places near the band of pump blade inlet on suction side when the pump discharge is small, and cavitation sites near the band of pump blade inlet on pressure side when the discharge is large. The hydraulic performance of pump runner will not change until water vapor accounts for about 42 percent of total volume.

scholarly journals Fatigue Life Prediction of a Pump Turbine Runner

2021 ◽  
Vol 627 ◽  
pp. 012025
Author(s):  
Q L He ◽  
T Liu ◽  
X L Yang ◽  
F N Chen ◽  
C Wang ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Fatigue Life Prediction ◽  
Pump Turbine ◽  
Turbine Runner

scholarly journals Distribution of Pressure Fluctuations in a Prototype Pump Turbine at Pump Mode

2014 ◽  
Vol 6 ◽  
pp. 923937 ◽  
Author(s):  
Yuekun Sun ◽  
Zhigang Zuo ◽  
Shuhong Liu ◽  
Jintao Liu ◽  
Yulin Wu
Keyword(s):  
Mass Flow ◽  
Pressure Fluctuations ◽  
Dominant Frequency ◽  
Pump Mode ◽  
Pump Turbine ◽  
Guide Vanes ◽  
Path Direction ◽  
Mass Flow Rates ◽  
Operating Points ◽  
Spiral Casing

Pressure fluctuations are very important characteristics in pump turbine's operation. Many researches have focused on the characteristics (amplitude and frequencies) of pressure fluctuations at specific locations, but little researches mentioned the distribution of pressure fluctuations in a pump turbine. In this paper, 3D numerical simulations using SSTk − ω turbulence model were carried out to predict the pressure fluctuations distribution in a prototype pump turbine at pump mode. Three operating points with different mass flow rates and different guide vanes’ openings were simulated. The numerical results show how pressure fluctuations at blade passing frequency (BPF) and its harmonics vary along the whole flow path direction, as well as along the circumferential direction. BPF is the first dominant frequency in vaneless space. Pressure fluctuation component at this frequency rapidly decays towards upstream (to draft tube) and downstream (to spiral casing). In contrast, pressure fluctuations component at 3BPF spreads to upstream and downstream with almost constant amplitude. Amplitude and frequencies of pressure fluctuations also vary along different circumferential locations in vaneless space. When the mass flow and guide vanes’ opening are different, the distribution of pressure fluctuations along the two directions is different basically.

Cavitation behavior study in the pump mode of a reversible pump-turbine

2018 ◽  
Vol 125 ◽  
pp. 655-667 ◽  
Author(s):  
Ran Tao ◽  
Ruofu Xiao ◽  
Fujun Wang ◽  
Weichao Liu
Keyword(s):  
Pump Mode ◽  
Pump Turbine ◽  
Behavior Study ◽  
Cavitation Behavior

Unsteady flow characteristics regarding hump instability in the first stage of a multistage pump-turbine in pump mode

2018 ◽  
Vol 127 ◽  
pp. 377-385 ◽  
Author(s):  
Jun Yang ◽  
Giorgio Pavesi ◽  
Xiaohua Liu ◽  
Tian Xie ◽  
Jun Liu
Keyword(s):  
Unsteady Flow ◽  
Flow Characteristics ◽  
Pump Mode ◽  
Pump Turbine ◽  
Multistage Pump

Cavitation Characteristics and Hydrodynamic Radial Forces of a Reversible Pump–Turbine at Pump Mode

2020 ◽  
Vol 146 (6) ◽  
pp. 04020066
Author(s):  
Ying-yuan Liu ◽  
Jian-guo Gong ◽  
Kang An ◽  
Le-qin Wang
Keyword(s):  
Pump Mode ◽  
Pump Turbine ◽  
Radial Forces
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