Hydraulic torque on the guide vane within the slight opening of pump turbine in turbine operating mode

Fan, Honggang; Yang, Haixia; Li, F C; Chen, N X

doi:10.1088/1755-1315/22/3/032050

Cited by 9 publications

(4 citation statements)

References 4 publications

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“…They found that the length of the lap between guide blades is closely related to the self-excited oscillation of guide vanes, and the vibration problem can be improved by modifying the profile [4]. The dynamic meshing technique was adopted to simulate the starting up and shutting down processes by Q F Ji and H G Fan, to capture the flow details between the guide vanes [7,8,9]. They found that there is bistable flow between guide vanes in pump condition, which was believed to be the cause of abnormal vibration.…”

Section: Introductionmentioning

confidence: 99%

Redesign of Adjustable Guide Vane Cascades of Pump Turbine and Its Effect on Self-Excited Vibrations at Slight Opening During Pump Mode’s Starting Up Process

Hao,

Wang,

et al. 2024

J. Phys.: Conf. Ser.

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Abnormal sounds and vibrations have occurred at several pumped storage power stations, when the guide vanes are at a slight opening during the pump mode’s starting up process. This paper proposes a modification method for active guide vanes to reduce the probability of abnormal vibration caused by self-excited vibration. A set of real machine guide vanes was selected to investigate the influence of different geometric parameters on self-excited vibration. Comprehensive analyses were conducted on the modified blades by the unsteady Reynolds-averaged Navier-Stokes solver and the 1DOF oscillator model (URANS-1DOF) coupling simulations. The results indicate that the probability of self-excited vibration divergence of the guide vanes is closely related to the degree of contraction and diffusion of the narrow gap flow channel. The self-excited vibration of the guide vane can be effectively suppressed by selecting appropriate overlapping length, contraction coefficient and diffusion coefficient. In addition, model tests have verified that the modification method has a slight impact on hydraulic performance.

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Section: Introductionmentioning

confidence: 99%

Redesign of Adjustable Guide Vane Cascades of Pump Turbine and Its Effect on Self-Excited Vibrations at Slight Opening During Pump Mode’s Starting Up Process

Hao,

Wang,

et al. 2024

J. Phys.: Conf. Ser.

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“…Some studies have also paid attention to the flow non-uniformity among multiple guide vane passages and the variation patterns of guide vane hydraulic torque. Fan et al [6] studied the relationship between noise frequency and head of a pump turbine at slight guide vane opening. By introducing the torque variation rate of a single guide vane and CFD flow simulation, they found that the repeating reversal of fluid in the guide vane region is the cause of vibration during load rejection.…”

Section: Introductionmentioning

confidence: 99%

Numerical Investigation of Guide Vane Hydraulic Torque Characteristics of a Pump Turbine in Pump Mode

Hu,

Xia,

Qiao

et al. 2024

HSET

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This study performs numerical simulations to investigate the hydraulic torque characteristics of a pump turbine at different guide vane openings in pump mode. The SST k-ω turbulence model is utilized to simulate the flow field at guide vane angles from 1° to 21°. The simulation results reveal that the overall hydraulic torque shows a decreasing trend as guide vane opening increases. However, significant asymmetry of hydraulic torque exists among different guide vanes at certain openings. This asymmetry highly correlates with the large vibration observed during pump start-up in the field test. By analysing pressure contours and velocity streamlines at openings of 3°, 9° and 17°, the causes for torque asymmetry are explored in depth. The primary factors are identified as circumferential flow non-uniformity, distinct flow discharge tendencies between boundary guide vanes, and reverse flow towards upstream stay vanes. The research findings provide important insights into the hydraulic torque characteristics of pump turbines at off-design conditions, and offer valuable guidance for the optimal design and stable operation of pump turbines in pump mode.

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“…Moreover, the vibration problem could be successfully eliminated by modifying the shape of the vanes. To address the issue of Tianhuangping, H. G. Fan [22] studied the HT of the GVs of the RPT during the startup and shutdown processes in the turbine mode with a 2D periodical CFD simulation. His work indicated that a repeated reversal of fluid occurred when the GVs worked with a slight opening during the shutdown process in the turbine mode.…”

Section: Introductionmentioning

confidence: 99%

Flow Deflection between Guide Vanes in a Pump Turbine Operating in Pump Mode with a Slight Opening

Liao

et al. 2022

Energies

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During the startup and shutdown processes of a reversible-pump turbine (RPT) working in pump mode, abnormal sounds and vibrations usually occur in the distributor when the guide vanes (GVs) are at a slight opening (max opening of about 6%). The objective of this paper is to apply a three-dimensional numerical CFD method to study the unsteady flow behavior in the guide vane region of a pump turbine operating in pump mode. The dynamic meshing technique is introduced to simulate the startup and shutdown processes, and it is shown to be critical in accurately capturing the details of the flow pattern variations. In addition, the RNG k-epsilon two-equation turbulence model is applied and the governing equations are discretized with the finite volume method. Moreover, the boundary conditions are set through the calculation of the transient process of the power station. The results show that the main flow between the GVs is deflected during the startup and shutdown processes. In the shutdown process, the deflection occurs when the guide vane opening (GVO) is between 1.99 and 5.32 degrees, on average. In the startup process, the deflection occurs when the GVO is between 2.83 and 4.11 degrees, on average. In these processes, the velocity field and pressure field change dramatically. Simultaneously, the hydraulic torque (HT) on the GVs has a sharp change. The abrupt change in the HT leads to vibrations and abnormal sounds.

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Hydraulic torque on the guide vane within the slight opening of pump turbine in turbine operating mode

Cited by 9 publications

References 4 publications

Redesign of Adjustable Guide Vane Cascades of Pump Turbine and Its Effect on Self-Excited Vibrations at Slight Opening During Pump Mode’s Starting Up Process

Redesign of Adjustable Guide Vane Cascades of Pump Turbine and Its Effect on Self-Excited Vibrations at Slight Opening During Pump Mode’s Starting Up Process

Numerical Investigation of Guide Vane Hydraulic Torque Characteristics of a Pump Turbine in Pump Mode

Flow Deflection between Guide Vanes in a Pump Turbine Operating in Pump Mode with a Slight Opening

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