Effect of Operating Head on Dynamic Behavior of a Pump–Turbine Runner in Turbine Mode

Li, Xiangyang; Cao, Jingwei; Zhuang, Jianling; Wu, Tongmao; Zheng, Hongyong; Wang, Yunfeng; Zheng, Wenxu; Lin, Guosheng; Wang, Zhengwei

doi:10.3390/en15114004

Cited by 4 publications

(2 citation statements)

References 27 publications

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“…Through the analysis of internal flow characteristics and pressure pulsation, it can be seen that the flow state of the runner and guide vanes is complicated, and the pressure pulsation in the vaneless zone is more significant under the combined influence of RSI and the rotating stall. To gain a better understanding, the weak-coupling method [32] is applied for analyzing the structure stress of runner and guide vanes. The discretized form of the linear dynamic equilibrium equation can be manifested as follows:…”

Section: Analysis Of Structure Stressmentioning

confidence: 99%

The Influence of Hydraulic Characteristics on Structural Performance in a Pump-Turbine under No-Load Conditions

Ren,

Zheng,

Yuan

et al. 2023

Processes

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The operating state of a pump-turbine unit under no-load conditions is directly related to its safe and stable operation. In order to probe into the influence of hydraulic characteristics on structural performance, a pump-turbine assembled in China is selected for research by using CFD (computational fluid dynamics) and unidirectional FSI (fluid–structure interaction) methods. The vortex distribution and the law of pressure pulsation propagation are analyzed to capture the peculiar flow phenomena. The results show that the vortex distribution in the runner channel appears initially at the suction side of the blades but then propagates toward the pressure side with GVO. This produces rotating stall frequencies (0.7fn) and a combination of the RSI, asymmetry of the water ring in vaneless space, and high-amplitude pressure pulsations in the downstream channel close to the runner inlet and elbow section of the draft tube. This, in turn, is associated with the structural stress of the runner and guide vane. The stress level of the guide vane becomes alleviated under no-load conditions with large GVO, but the stress distribution of the runner is no longer symmetrical, which aligns with the vortex evolution in the runner passage. The stress concentration that develops further along the blade root increases the structural failure, which is also captured and verified as a crack in the prototype runner. The phenomena suggest that the RPT should avoid operating under no-load conditions with large GVO as far as possible. Therefore, in the design or optimization of the pump-turbine unit, the structures of the guide vanes and runner could be treated as a whole to investigate the resulting internal flow and structure characteristics.

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Section: Analysis Of Structure Stressmentioning

confidence: 99%

The Influence of Hydraulic Characteristics on Structural Performance in a Pump-Turbine under No-Load Conditions

Ren,

Zheng,

Yuan

et al. 2023

Processes

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“…This instability can lead to the emergence of severe vortex phenomena [2,3] within the draft tube. And under the influence of vortex-induced vibration, the hydraulic unit may experience abnormal overall deflection [4,5]. Therefore, investigating the hydraulic characteristic distribution in the internal flow field of the pumpturbine and analyzing the energy loss quantitatively due to different types of vortex ropes under part load conditions [6] are of vital importance.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Hydraulic Losses in Vortex Rope Inside the Draft Tube of Francis Pump-Turbine Based on Entropy Production Theory

Wang,

Zhou,

Guo

et al. 2023

Machines

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The existence of vortex ropes inside the draft tube significantly impacts hydraulic efficiency and operational stability, and few studies on the formation mechanism of vortex ropes and hydraulic loss problems have been explored. Hence, in this paper, we build an inherent correlation between the local entropy production rate (LEPR) in the draft tube and the dynamics of vortex motion, by incorporating the vortex identification method Ω~R with entropy production theory, using the OpenFOAM-v2212 software. From the analysis of the entropy production theory, the entropy production rate caused by turbulence dissipation (EPTD) is responsible for the majority of energy loss in the form of entropy production rate, accounting for about 87% of the total entropy production rate (TEPR) in different load operations. Comparatively, the entropy production rate caused by wall shear stress (EPWS) can account for up to 12%, while the entropy production rate due to direct dissipation (EPDD) plays a minor role in TEPR. The rotating vortex rope movement of the unit at part load conditions leads to more intense LEPR. Therefore, to determine the hydraulic loss caused by the vortex rope, the TEPR at the cross-section can be used to assess the hydraulic characteristics of the draft tube.

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Failure analysis on the bolt connecting the head-cover and stay ring in pumped storage unit: Part Ⅰ-Experimental study

Zhao,

Luo,

Zhai

et al. 2023

Engineering Failure Analysis

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Effect of Operating Head on Dynamic Behavior of a Pump–Turbine Runner in Turbine Mode

Cited by 4 publications

References 27 publications

The Influence of Hydraulic Characteristics on Structural Performance in a Pump-Turbine under No-Load Conditions

The Influence of Hydraulic Characteristics on Structural Performance in a Pump-Turbine under No-Load Conditions

Analysis of Hydraulic Losses in Vortex Rope Inside the Draft Tube of Francis Pump-Turbine Based on Entropy Production Theory

Failure analysis on the bolt connecting the head-cover and stay ring in pumped storage unit: Part Ⅰ-Experimental study

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