Dynamic characteristic analysis of pressure pulsations of a pump turbine in turbine mode utilizing variational mode decomposition combined with Hilbert transform

Zheng, Xianghao; Zhang, Suqi; Zhang, Yuning; Li, Jinwei

doi:10.1016/j.energy.2023.128148

Cited by 16 publications

(3 citation statements)

References 33 publications

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“…Overall, the characteristics of pressure fluctuation in turbine mode showed some similarities with those reported in reference [35]. However, under near-full-load conditions, the reference identified pressure modes corresponding to rotor-stator interaction (RSI), which were not distinctly observed in this study.…”

Section: 15 X For Peer Reviewsupporting

confidence: 76%

A Field Investigation of Stability Characteristics of Pressure Fluctuation and Vibration in Prototype Pump Turbine at Multiple Working Points

Hu,

Xia,

Song

et al. 2023

Water

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In practical operation, pump turbines typically operate far from their designed working points, which has a significant impact on the stability of the unit’s operation. In this paper, we conducted a field test to investigate the stability characteristics of prototype pump turbines at different working points. By adjusting the given power of the generator in a stepwise manner to control its working point, we obtained the statistical and spectral characteristics of pressure signals and acceleration signals. In turbine mode, the result shows that, at low, medium, and high power, the variation in pressure fluctuation characteristics is influenced by three different factors, while vibration generally reaches its maximum value at approximately 50 MW. In pump mode, variations in pressure were observed among different measurement points in the low-frequency range, and the characteristics of vibration acceleration were influenced by both the rotor–stator interaction (RSI) and the structural modal frequencies. We emphasized that the high-frequency bands have influences on the unit comparable in magnitude to those of the rotor–stator interaction, which has rarely been mentioned in previous studies. Through detailed testing and analysis of the unit’s actual operation, we can gain a better understanding of its behavior and performance in the turbine and pump modes, and these results hold significant importance for ensuring the stability and reliability of the unit.

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Section: 15 X For Peer Reviewsupporting

confidence: 76%

A Field Investigation of Stability Characteristics of Pressure Fluctuation and Vibration in Prototype Pump Turbine at Multiple Working Points

Hu,

Xia,

Song

et al. 2023

Water

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“…Finally, the total entropy production rate (TEPR) within the computational domain encompasses the sum of direct dissipation, turbulent dissipation, and wall friction. The total entropy production is obtained through the volume integration using Equation (25).…”

Section: Entropy Production Theory Modelmentioning

confidence: 99%

“…It is commonly acknowledged that the movement of vortex ropes [20,21] in draft tubes results in considerable hydraulic losses [22,23]. These losses have an impact not only on the overall hydraulic efficiency of the unit but also lead to low-frequency pulsations [24,25] that present risks to the operation of power plants. In recent years, many scholars have embraced a perspective based on the second law of thermodynamics, establishing a link between the distribution of entropy production and hydraulic losses.…”

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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A universal hydraulic-mechanical diagnostic framework based on feature extraction of abnormal on-field measurements: Application in micro pumped storage system

Zhao,

Chen,

et al. 2024

Applied Energy

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Dynamic characteristic analysis of pressure pulsations of a pump turbine in turbine mode utilizing variational mode decomposition combined with Hilbert transform

Cited by 16 publications

References 33 publications

A Field Investigation of Stability Characteristics of Pressure Fluctuation and Vibration in Prototype Pump Turbine at Multiple Working Points

A Field Investigation of Stability Characteristics of Pressure Fluctuation and Vibration in Prototype Pump Turbine at Multiple Working Points

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

A universal hydraulic-mechanical diagnostic framework based on feature extraction of abnormal on-field measurements: Application in micro pumped storage system

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