Research on the performance of pump-turbine during the transition process from pump mode to turbine mode DOI Creative Commons

Zhe Man,

Zhe Xu,

Zhonghua Gui

et al.

Frontiers in Energy Research, Journal Year: 2024, Volume and Issue: 12

Published: Aug. 1, 2024

In current engineering, the transition process of pump turbines from to turbine mode mainly includes shutdown operating and startup operating, switching working conditions mostly depends on opening closing ball valve. While, this article focuses transitional condition without relying valve, which will significantly reduce response time unit enable quick in emergency situations. study, torque balance equation is employed analyze entire flow system operation. Additionally, entropy production theory utilized investigate correlation between pressure, state, energy loss pump-turbine, shedding light changes external characteristics through evolution internal characteristics. Furthermore, segmented into five stages based variations guide vanes (GV). The findings reveal that rotation GV triggers sharp fluctuations static torque, axial force. During stage four, initiation all three positions results an increase rate accompanied by a decrease two, closure leads pressure within spiral casing (SC) stay (SV) domains, coupled with bladeless zone, runner, draft tube domains. Simultaneously, difference both sides runner decreases significantly, directly causing drop three, interrupts resulting significant backflow SC, SV, alongside high-speed circulation area. Moreover, location high (EPR) value aligns reflux indicating considerable attributable reflux. above research provide reference for rapid

Language: Английский

Study on evolution characteristics of energy dissipation and vortex in pump-turbine during load rejection transition process DOI
Yonggang Lu, Zhiwang Liu,

Yun Zhao

et al.

Physics of Fluids, Journal Year: 2025, Volume and Issue: 37(2)

Published: Feb. 1, 2025

The widespread adoption of intermittent wind and solar energy sources disrupts the stability power grids, necessitating frequent load rejection processes for pump-turbine. This jeopardizes pump-turbine units. To investigate operating behavior units during rejection, this study focuses on a Francis reversible Employing results from one-dimensional characteristic line method as boundary conditions, three-dimensional numerical simulations are conducted. entropy production theory was employed to quantify loss in different components, including direct dissipation, turbulent wall shear stress. And pressure curves runner blades at spans extracted. flow characteristics, losses, loads within passage analyzed various moments process. Results demonstrate that when unit undergoes it repeatedly transitions into out S-characteristic region. state is most unfavorable under reverse pump with reaching its maximum value 339 160 W/K. When unit's rotational speed increased beyond 1.1nd, water thrust torque underwent drastic changes. Moreover, significant variations runaway difference among up 33 000 kPa. These findings provide scientific basis ensuring safe reliable operation processes.

Language: Английский

Citations

2
Unstable pressure fluctuations in the vaneless space of high-head reversible pump-turbines – A systematic review DOI
Bhushan R. Rode, Arun Kumar

Journal of Energy Storage, Journal Year: 2023, Volume and Issue: 72, P. 108397 - 108397

Published: July 20, 2023

Language: Английский

Citations

30
The mechanism of internal energy losses in double suction centrifugal pumps under direct and reverse conditions DOI
Senchun Miao,

Xingxing Tan,

Luo Wen

et al.

Energy, Journal Year: 2024, Volume and Issue: 306, P. 132547 - 132547

Published: July 24, 2024

Language: Английский

Citations

10
Mechanism of the influence of sand on the energy dissipation inside the hydraulic turbine under sediment erosion condition DOI
Xijie Song,

Yongyao Luo,

Zhengwei Wang

et al.

Energy, Journal Year: 2024, Volume and Issue: 294, P. 130794 - 130794

Published: Feb. 26, 2024

Language: Английский

Citations

9
Time-mean equation and multi-field coupling numerical method for low-Reynolds-number turbulent flow in ferrofluid DOI
Wangxu Li, Zhenggui Li, Wei Han

et al.

Physics of Fluids, Journal Year: 2023, Volume and Issue: 35(12)

Published: Dec. 1, 2023

Significant breakthroughs in the theory and applications of ferrofluid have broadened their usage areas such as sealing actuation. However, development numerical dynamics has been slow owing to inadequate multi-field coupling techniques incomplete equations for turbulence flow. The understanding low-Reynolds-number turbulent flow mechanisms at small scales, particularly actuation applications, remains limited, therefore hindering further advancements. This article delves into general fluid discusses influence different-scale vortices on average motion. An anisotropic model was introduced verified using around a cylinder. Magnetic fields data were coupled through node ranking interpolation methods. By introducing interaction force magnetic dipoles, refined within Euler grids, thereby establishing motion ferrofluids influenced by multiple fields. applied study deformation migration processes under an external field. variations forces encapsulated, macroscopic comparisons made experiments, which demonstrated good consistency. research provides new methods ideas use studies. Additionally, it offers valuable technical support that can aid developing industrial products driving devices based ferrofluids.

Language: Английский

Citations

22
Energy loss analysis of transition simulation for a prototype reversible pump turbine during load rejection process DOI
Faye Jin,

Yongyao Luo,

Qiang Zhao

et al.

Energy, Journal Year: 2023, Volume and Issue: 284, P. 129216 - 129216

Published: Sept. 29, 2023

Language: Английский

Citations

16
PaT-ID: A tool for the selection of the optimal pump as turbine for a water distribution network DOI Creative Commons
Gabriella Balacco, Gaetano Daniele Fiorese, Maria Rosaria Alfio

et al.

Energy, Journal Year: 2023, Volume and Issue: 282, P. 128366 - 128366

Published: July 8, 2023

In a historical context where renewable energy is increasingly being adopted, the installation of Pumps as Turbines (PaTs) in Water Distribution Networks (WDNs) gaining relevance scientific community. The selection PaT to be installed WDN complex, requiring trade-off between technical and economic aspects. This paper presents methodology for guiding based on characteristics WDN, predicting its characteristic curves, estimating daily power generation. proposed algorithm has been automated computer tool called PaT-ID. innovative aspects this concern general applicability any machine catalogue. It automatically selects most useful considering input water demand trend hydraulic head available PaT. addition, decides series or parallel layouts if necessary. Finally, absence data, PaT-ID provides first-level analysis define potential site production, simulating flow rate data. code validated with two case studies analysed previous works.

Language: Английский

Citations

14
Improvement in energy performance from the construction of inlet guide vane and diffuser vane geometries in an axial-flow pump DOI Creative Commons
Duc-Anh Nguyen, Cong-Τruong Dinh, Jin‐Hyuk Kim

et al.

Scientific Reports, Journal Year: 2024, Volume and Issue: 14(1)

Published: Jan. 3, 2024

Advanced inlet guide vane (IGV) and diffuser (DV) geometries were constructed in an effort to increase the energy performance of axial-flow pump at best efficiency point (BEP). DV setting angles also investigated off-design points. By integrating advantages adjustable IGV, combinations IGV thoroughly analyzed by way loss. The asymmetrical geometry upgraded through use a hydrofoil profile, resulted higher hydraulic compared that reference model. total head BEP increased significantly with implementation new DV, 1.456% 5.756% over those model, respectively. Using reduced unsteady turbulent flow behind trailing edge under all rate conditions, resulting reduction vibration noise. positive high-flow-rate region, whereas negative produced good low-flow-rate region. Combining model significant head, more optimal provided angles. At low-velocity zone is closely related high entropy generation. Furthermore, these high-entropy generation regions follow trajectory zones. However, not strongly associated region when operating conditions.

Language: Английский

Citations

6
Research on the starting-up process of a prototype reversible pump turbine with misaligned guide vanes: An energy loss analysis DOI
Faye Jin,

Yongyao Luo,

Zhengwei Wang

et al.

Energy, Journal Year: 2024, Volume and Issue: 304, P. 132219 - 132219

Published: June 26, 2024

Language: Английский

Citations

6
Thermo-hydrodynamic lubrication and energy dissipation mechanism of a pump-turbine thrust bearing in load-rejection process DOI Open Access
Jingwei Cao,

Yongyao Luo,

Liwei Deng

et al.

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(3)

Published: March 1, 2024

The dynamic behavior of the pump-turbine thrust bearing is important to safety operation unit. This paper analyzed lubrication and energy dissipation mechanism during load-rejection based on thermo-hydrodynamic model. results show that variation axial force maximum pad surface pressure basically consistent with inclination surface. change friction loss rotational speed, while temperature affected by combination speed. chaotic flow in oil tank accompanied different forms vortices, such as Taylor vortex pairs, Karman a significant asymmetry distribution. groove has an effect film. provides theoretical basis for design optimization bearings, reference solving problems wear, mist, other related bearings engineering.

Language: Английский

Citations

4