Chaotic dynamic characteristics of pressure fluctuation signals in hydro-turbine

Su, Wen-Tao; Li, Xiaobin; Lan, Chaofeng; An, Shi; Wang, Jiansheng; Li, Feng‐Chen

doi:10.1007/s12206-016-1020-x

Cited by 14 publications

(4 citation statements)

References 19 publications

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“…Tang et al studied the Francis turbine inner vortex characteristics by using numerical methods [4]. Su et al studied the pressure pulsation characteristics of a Francis turbine under local flow conditions and concluded that chaotic attractors do exist in the turbine pressure fluctuation signal [5]. Ren et al performed numerical simulations of a mixed-flow turbine in a power station.…”

Section: Introductionmentioning

confidence: 99%

Study on the design of short blade offset for the long and short blade runner of 1000 MW hydraulic turbine units

Lu,

Zhang,

Chen

et al. 2024

J. Phys.: Conf. Ser.

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For such complex rotating machinery as hydraulic turbine, the hydraulic operation characteristics of the hydraulic turbine unit are significantly impacted by the short blade of the runner used as the splitter blade. To find the optimum position of the short blade, the study object is the 1000 MW hydraulic turbine, selects three circumferential offset positions of the short blade for numerical simulation calculation, obtains the runner flow pattern at different offsets, and explores the impact on the short blade offset on the vortex and pressure pulsation in the runner. The results show that the counterclockwise offset of the short blade will improve the flow pattern of the runner, reduce the scale of vortex in the runner and enhance the efficiency of the hydraulic turbine. The counterclockwise offset will increase the interference while decreasing the pressure pulsation in the vaneless region, at the runner’s inlet, and downstream of the short blade. When the offset δ=0.6, the peak-valley difference of pressure fluctuation in the vaneless zone is the smallest, accounting for only 1.38 % of the rated head. The main frequency of the vaneless zone gradually changes from 15fn to 30fn , and the main frequency of the runner inlet and the short blade downstream is 24fn . Due to the different weakening effects of short blades on the interference, low-frequency pulsation components of 4fn and 8fn appear.

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Section: Introductionmentioning

confidence: 99%

Study on the design of short blade offset for the long and short blade runner of 1000 MW hydraulic turbine units

Lu,

Zhang,

Chen

et al. 2024

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

show abstract

“…Wang et al [17] investigated the characteristic frequencies in the unsteady hydraulic behavior of a hydraulic turbine experimentally wherein their results showed that the pressure fluctuation in a draft tube is stronger than that in the upstream flow passage. A more recent study by Su et al [18] investigated the chaotic dynamic characteristics of pressure fluctuation signals in hydroturbines, and their results revealed that the main energy pressure fluctuations in a draft tube are located at low-frequency regions. Also recently, Glowacz [19] investigated the fault diagnosis of a single-phase induction motor based on acoustic signals and then proposed a signal processing method for early fault diagnosis of electrical and mechanical faults of rotating machines.…”

Section: Introductionmentioning

confidence: 99%

Flow and Fast Fourier Transform Analyses for Tip Clearance Effect in an Operating Kaplan Turbine

et al. 2019

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The Kaplan turbine is an axial propeller-type turbine that can simultaneously control guide vanes and runner blades, thus allowing its application in a wide range of operations. Here, turbine tip clearance plays a crucial role in turbine design and operation as high tip clearance flow can lead to a change in the flow pattern, resulting in a loss of efficiency and finally the breakdown of hydro turbines. This research investigates tip clearance flow characteristics and undertakes a transient fast Fourier transform (FFT) analysis of a Kaplan turbine. In this study, the computational fluid dynamics method was used to investigate the Kaplan turbine performance with tip clearance gaps at different operating conditions. Numerical performance was verified with experimental results. In particular, a parametric study was carried out including the different geometrical parameters such as tip clearance between stationary and rotating chambers. In addition, an FFT analysis was performed by monitoring dynamic pressure fluctuation on the rotor. Here, increases in tip clearance were shown to occur with decreases in efficiency owing to unsteady flow. With this study’s focus on analyzing the flow of the tip clearance and its effect on turbine performance as well as hydraulic efficiency, it aims to improve the understanding on the flow field in a Kaplan turbine.

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“…Historically, stability modeling has been split in two directions (see Fig. 1), focusing on the hydro-turbine governing systems (HTGSs) [3] and the shaft systems of hydro-turbine generator units (SSHTGs) [4]. (a) A hydro-turbine governing system (b) A hydro-turbine generator set Fig.…”

Section: Introductionmentioning

confidence: 99%

Mathematical model and parametric uncertainty analysis of a hydraulic generating system

Chen

Patelli

et al. 2019

Renewable Energy

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Conversion efficiency and unit vibration are two important indexes in evaluating the stability of hydraulic generating systems (HGSs). Most of related studies have been carried out in the deterministic theory framework. As running times of HGS increased, understanding uncertainties and limitations of model parameters are important for accurate modeling and stability evaluation. In this study, first, we establish an integrated model of a HGS by proposing unbalanced hydraulic forces based on the Kutta-Zhoukowski assumption. Second, global sensitivity and parametric interactions for conversion efficiency and unit vibration are investigated based on this model. Finally, the novel unified model is verified with two conventional models. This integrated and accurate mathematical model is a major advance in the diagnosis and prediction of failures in hydropower operation. *Revised Manuscript-Clear Click here to download Revised Manuscript-Clear: 20180520-a clear manuscript.docx Click here to view linked References

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Chaotic dynamic characteristics of pressure fluctuation signals in hydro-turbine

Cited by 14 publications

References 19 publications

Study on the design of short blade offset for the long and short blade runner of 1000 MW hydraulic turbine units

Study on the design of short blade offset for the long and short blade runner of 1000 MW hydraulic turbine units

Flow and Fast Fourier Transform Analyses for Tip Clearance Effect in an Operating Kaplan Turbine

Mathematical model and parametric uncertainty analysis of a hydraulic generating system

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