Effect of the Vortex on the Movement Law of Sand Particles in the Hump Region of Pump-Turbine DOI Creative Commons
Guangtai Shi, Xunyun Ye, Yexiang Xiao

et al.

Journal of Marine Science and Engineering, Journal Year: 2024, Volume and Issue: 12(12), P. 2190 - 2190

Published: Nov. 30, 2024

The pump turbine, as the core equipment of a pumped storage power plant, is most likely to operate in hump zone between condition changes, which has great impact on stable operation and high sedimentation natural river will lead wear tear overflow components equipment. Therefore, this paper based Euler–Lagrange model, seeks investigate distribution vortices turbine its effect movement sand particles. study shows that flow rate increases, strip vortex straight cone section draft tube becomes elongated, cluster elbow gradually decreases. encourages particles move along surface, while hinders accumulation areas increase axially laterally, respectively. blade runner occupies channel near pressure surface towards suction resulting serious surface. As number blades where accumulate increases area moves cover plate outlet. separation double-row cascade decreases drives middle lower sections vanes. stay vane with increasing rate, but guide vanes then wall volute at outlet first decreases, disappears, finally reappears. suppresses movement, changes from elongated lumpy due flow. results provide an important theoretical reference for reducing components.

Language: Английский

Vortex and energy characteristics in the hump region of pump-turbines based on the rigid vorticity and local hydraulic loss method DOI
Lianchen Xu, Yuquan Zhang, Junhui Xu

et al.

Physics of Fluids, Journal Year: 2025, Volume and Issue: 37(3)

Published: March 1, 2025

With the climate change hazards and implementation of pumped-storage hydropower units in power grid increases, maintaining hydraulic stability hump region is primordial for energy transition yet presents a significant challenge. This study investigates loss characteristics instability pump-turbine during operation using both model testing computational fluid dynamics methods. The results indicate that predominantly occurs guide vane (GV) passage draft tube (DT), more with flow reduction. Specifically, vaneless space linked to shear vorticity, while rigid vorticity plays prominent role GV DT. Analysis Rortex enstrophy transport equation shows pseudo-Lamb term dominant factor influencing vortex evolution. Additionally, combining Reynolds-averaged Navier–Stokes equations particle image velocimetry experiments reveals near zero-velocity gradient region, effects are concentrated core on runner side, primarily wake direction motion.

Language: Английский

Citations

1
Analysis of unstable flow characteristics in the blade region of Francis pump-turbine under non-design conditions DOI

Jiawu Zhou,

Yuquan Zhang,

Yuan Zheng

et al.

Physics of Fluids, Journal Year: 2025, Volume and Issue: 37(1)

Published: Jan. 1, 2025

Under non-design situations, the Francis pump-turbine, a frequently employed core energy conversion device in pumped storage power plants, plays significant role ensuring their stable operation. This article examines unstable flow inside pump-turbine using gradient theory and numerical computations model experiments. Research has indicated that forced impacts separation between fluids blades are causes of deteriorating mechanical gradients, whereas non-optimal angles stay guide vanes can readily cause separation. The strong helical at blade inlet is primary flow, hub outlet locations for high shear force work area brought on by large-scale vortex structures, middle portion impeller where field begins needs more attention.

Language: Английский

Citations

0
Compressibility effects and rotational dynamics of stall cells in a pump turbine diffuser during hump instability DOI
Jun Yang,

Yingying Zheng,

Junzhu Wang

et al.

Physics of Fluids, Journal Year: 2025, Volume and Issue: 37(5)

Published: May 1, 2025

The hump phenomenon significantly impacts the operational stability of pump turbines, with rotating stall in diffuser channels being a key unsteady flow structure and primary cause instability. This study investigates compressibility effects rotational behavior cells during instability conditions using proper orthogonal decomposition two-dimensional frequency domain visualization methods. evolution process is analyzed terms spatial distribution, intensity, characteristics. results reveal that working fluid partially suppresses transition into stable cells. Meanwhile, circumferential propagation identified as contributor to significant hydraulic losses critical factor phenomenon. Consequently, suppressing not only effectively reduces mitigates phenomenon, but also expands unit's safe operating range enhances its performance under off-design conditions, offering potential strategies for improving turbine stability.

Language: Английский

Citations

0
Effect of the Vortex on the Movement Law of Sand Particles in the Hump Region of Pump-Turbine DOI Creative Commons
Guangtai Shi, Xunyun Ye, Yexiang Xiao

et al.

Journal of Marine Science and Engineering, Journal Year: 2024, Volume and Issue: 12(12), P. 2190 - 2190

Published: Nov. 30, 2024

The pump turbine, as the core equipment of a pumped storage power plant, is most likely to operate in hump zone between condition changes, which has great impact on stable operation and high sedimentation natural river will lead wear tear overflow components equipment. Therefore, this paper based Euler–Lagrange model, seeks investigate distribution vortices turbine its effect movement sand particles. study shows that flow rate increases, strip vortex straight cone section draft tube becomes elongated, cluster elbow gradually decreases. encourages particles move along surface, while hinders accumulation areas increase axially laterally, respectively. blade runner occupies channel near pressure surface towards suction resulting serious surface. As number blades where accumulate increases area moves cover plate outlet. separation double-row cascade decreases drives middle lower sections vanes. stay vane with increasing rate, but guide vanes then wall volute at outlet first decreases, disappears, finally reappears. suppresses movement, changes from elongated lumpy due flow. results provide an important theoretical reference for reducing components.

Language: Английский

Citations

0