Guide vane profile optimization of pump-turbine for grid connection performance improvement

Zhang, Fangfang; Fang, Mingkun; Pan, Jiale; Tao, Ran; Zhu, Di; Liu, Weichao; Xiao, Ruofu

doi:10.1016/j.energy.2023.127369

Cited by 18 publications

(4 citation statements)

References 34 publications

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“…The impact of flow pulsation on the stability of runaway has been fully explained. Zhang et al [19] studied the influence of guide vane geometry on the pump-turbine's runaway instability. The stability is improved by restraining the bad flow at the runner outlet and draft tube inlet.…”

Section: Introductionmentioning

confidence: 99%

Influence of Guide Vane Opening on the Runaway Stability of a Pump-Turbine Used for Hydropower and Ocean Power

Zhu,

Yan,

Guang

et al. 2023

JMSE

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Runaway is a common phenomenon in pump-turbines for hydropower and ocean power, accompanied by strong instability, which can easily lead to accidents. This study reveals the stability during the runaway process of a pump-turbine, mainly exploring the phenomenon of guide vane rejection happening in transition conditions when dealing with hydropower or ocean power. Through model experiments and computational fluid dynamics numerical simulations, the pressure pulsation when reaching runaway was compared under different guide vane opening angles. The amplitude of pressure pulsation measured in the experiment increases with the increase in guide vane opening, but there are also local changes in size and peak. The simulation results show that when the guide vane opening angle is 12 degrees, the vortex flow in the area between the guide vane and the runner of the unit increases, leading to instability. When the opening angle of the guide vane is between 12 and 20 degrees, the vortex flow intensity does not change much and the distribution becomes uniform, resulting in a decrease in the amplitude of pressure fluctuations. The pulsation of the flow field causes a dissipation of flow energy. Relationships can be found among velocity field, vortex intensity, and entropy production. This study is of great significance for ensuring the stable operation of pump-turbines.

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Section: Introductionmentioning

confidence: 99%

Influence of Guide Vane Opening on the Runaway Stability of a Pump-Turbine Used for Hydropower and Ocean Power

Zhu,

Yan,

Guang

et al. 2023

JMSE

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“…Many researchers have indeed found that variable-speed operation can effectively improve the hydraulic performance of pump turbines. Due to the difficulty of pump turbine calculations, many studies have proposed optimization strategies combining fuzzy logic (FL) and genetic algorithms (GA) [25][26][27]. In summary, variable-speed operation has been shown to enhance the efficiency and stability of pump turbines [28].…”

Section: Introductionmentioning

confidence: 99%

Hydraulic Characterization of Variable-Speed Pump Turbine under Typical Pumping Modes

Shang,

Cao,

Wang

et al. 2023

Processes

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The pump turbine is a crucial component of pumped storage hydropower plants. When operated at a constant speed, it does not respond well to variations in the grid frequency. To improve the hydraulic efficiency of pumped storage units, variable-speed units have been introduced. However, the mechanism of variable-speed pump turbines has not been extensively studied numerically. In this study, the flow characteristics of a variable-speed pump turbine were computed under two typical pumping modes, the maximum head and minimum flow rate condition, as well as the minimum head and maximum flow rate condition. The computed results aligned with experimental results, and the changing trends of hydraulic thrust under these two pumping modes were discussed. The error for the Hmax, Qmin condition was 1.3%, and the error for the Hmin, Qmax condition was −1.9%. These error values fell within a reasonable range. The research findings indicate that in the Hmax, Qmin condition, the flow within the flow passage exhibited higher velocity, which was 84.87 m/s, increased flow turbulence, larger pressure fluctuations, and poorer unit stability. On the other hand, in the Hmin, Qmax condition, both the axial hydraulic thrust and radial forces were greater, and there were sudden changes in the extreme values of pressure fluctuations over a certain period of time. It is recommended to avoid operating the variable-speed pump turbine under these two conditions during pumping operations.

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“…With the depletion of renewable energy sources in the world, the International Energy Agency has released the '2050 Net Zero Emissions Roadmap for the Global Energy Industry', which sets requirements for the global use of clean, green, and renewable energy. Among the many renewable energy sources, such as wind energy, solar energy, hydropower, and tidal energy, hydraulic energy is widely used as a clean and pollution-free form of energy with a high conversion rate, abundant reserves, and high stability, while water conservancy projects are being built around the world and hydropower stations are thriving worldwide [1][2][3].…”

Section: Introductionmentioning

confidence: 99%

Investigation of Fractal Characteristics of Karman Vortex for NACA0009 Hydrofoil

et al. 2023

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A Karman vortex is a phenomenon of fluid flow that can cause fluctuation and vibration. As a result, it leads to fatigue damage to structures and induces safety accidents. Therefore, the analysis of the shedding law and strength of the Karman vortex is significant. To further understand the laws of turbulent Karman vortex shedding and strength, this study conducts a numerical vorticity simulation of a Karman vortex at the trailing edge of a hydrofoil based on the two-dimensional simplified model of the NACA0009 hydrofoil under different Reynolds numbers. Combined with image segmentation technology, the fractal characteristics of a turbulent Karman vortex at the trailing edge of a hydrofoil are extracted, the number and total area of vortex cores are calculated, and the fractal dimension of the vortex is obtained. The results show that the fractal dimension can characterize the change in vortex shape and strength under different Reynolds numbers, and that the fractal analysis method is feasible and effective for the shedding analysis of a turbulent Karman vortex.

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Guide vane profile optimization of pump-turbine for grid connection performance improvement

Cited by 18 publications

References 34 publications

Influence of Guide Vane Opening on the Runaway Stability of a Pump-Turbine Used for Hydropower and Ocean Power

Influence of Guide Vane Opening on the Runaway Stability of a Pump-Turbine Used for Hydropower and Ocean Power

Hydraulic Characterization of Variable-Speed Pump Turbine under Typical Pumping Modes

Investigation of Fractal Characteristics of Karman Vortex for NACA0009 Hydrofoil

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