Effect of impeller and diffuser matching optimization on broadening operating range of storage pump

Journal of Energy Storage, Journal Year: 2023, Volume and Issue: 72, P. 108737 - 108737

Published: Aug. 27, 2023

Language: Английский

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Study on rotating stall characteristics of centrifugal pumps based on gamma transition model

Physics of Fluids, Journal Year: 2024, Volume and Issue: 36(5)

Published: May 1, 2024

The phenomenon of rotating stall in centrifugal pumps is closely associated with the evolution blade boundary layer. Aiming to accurately predict characteristics layer, this study investigates pump impellers using gamma (γ) transition model. accuracy numerical simulation was confirmed by comparing its conclusions results testing. In calculations considering characteristics, distribution low-pressure areas inside impeller relatively discontinuous, while pressure more uniform. However, without transition, regions neighboring flow channels exhibit a tendency be interconnected, resulting variable distribution, and contour at outlet closer parallel. dynamic were obtained through mode decomposition method, including frequency, structure, process vortex. Through modal reconstruction, it discovered that impeller's rotation causes vortex undergo periodic fluctuations. not stationary but moves synchronously blades. At different time points, exhibits changes. suction entrance, initially appears. Subsequently, multiple structures resulted channel blockage. After period development, excess merge generate typical “8” shaped structure move toward exit. Finally, exit disappears, new generated inlet surface.

Language: Английский

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Numerical analysis of energy loss in electric submersible pump under stall conditions based on entropy production theory

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

Published: Jan. 1, 2025

Studying the energy loss characteristics of electrical submersible pump (ESP) under stalling conditions is beneficial for reducing global carbon emissions. By combining steady and unsteady numerical simulations with entropy production (EP) theory, evolution internal vortices in ESP analyzed, a theoretical model predicting based on EP established. The results show that turbulent dissipation inside main component total production. Under critical stall conditions, stability impeller single-stage higher. However, first-stage multi-stage ESP, periodic shedding breakdown lead to flow field at inlet diffuser, resulting increased impact losses. deep recirculation exhibit symmetric distribution. In pumps, period asynchronous rotation period. There are differences each channel, nonsymmetrical distributions circumferential radial directions. interaction between outlet diffuser passage leads formation multiple high-energy, small-scale vortex structures entrance next-stage impeller. It will further fluid separation cause enter condition. research offer valuable insights can be utilized as references optimizing design application ESPs.

Language: Английский

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Transient flow characteristics and energy loss investigation in a desalination energy recovery device under rotor system axial sliding conditions: Focusing on the turbine side

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

Published: Jan. 1, 2025

The energy recovery integrated machine can effectively reduce the consumption of a seawater desalination system by harnessing residual pressure in high-pressure waste liquid. However, axial force imbalance between pump side and turbine lead to sliding rotor system, then change clearance size. objective this paper is investigate unsteady flow pattern with sliding, focusing specifically on under coupled operation conditions. results show that increased size performance decreases obviously but little affected. entropy production analysis impeller, draft tube volute are core regions loss turbine. instability tube, chamber amplified size, resulting greater turbulent kinetic dissipation. Unsteady phenomena such as jet, separation vortex front cause great loss. dominant frequency fluctuation impeller generally fn. 6fn. With enhanced. generation large-scale leakage outlet region. near wall gradually changes from 6fn As increases, intensified gradual strength outside tube.

Language: Английский

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Experimental and Numerical Study of Hydraulic Characteristics and Pressurization Deterioration Mechanism of a Three-Stage Mixed-Flow Electrical Submersible Pump Under Gas-Liquid Condition

Journal of Fluids Engineering, Journal Year: 2024, Volume and Issue: 146(9)

Published: March 16, 2024

Abstract Electrical submersible pump (ESP) is extensively utilized in industrial sectors such as petroleum, chemical, and nuclear energy. However, ESPs experience pressurization deterioration due to the high gas volume fraction (GVF), resulting failure. In this paper, a three-stage mixed-flow ESP with closed impeller structure detailed analysis. The interstage hydraulic characteristics mechanism of are investigated at various rotational speeds inlet conditions by combining experimental simulation. population balance model (PBM) renormalization group (RNG) k − ε employed. As liquid flowrate increases, experiences “three-stage” downward trend pressurization. It discovered that first booster stage has lower inflow velocity flow separation degree compared subsequent stages, greater liquid-phase capacity. gas–liquid exhibits wave-shaped significant stage-wise when low. Once (IGVF) reaches critical GVF, aggregates on impeller's suction surface removed outlet, creating an annular air mass, which creates chaotic vortex absorbing fluids' kinetic

Language: Английский

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

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

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Energy Performance Prediction Model for Mixed-Flow Pumps by Considering the Effect of Incoming Prerotation

Journal of Fluids Engineering, Journal Year: 2023, Volume and Issue: 146(6)

Published: Dec. 29, 2023

Abstract Mixed-flow pump is one of the most broadly applied sorts power equipment in field petrochemical and water conservancy. The effect inlet prerotation on energy characteristics operational stability a significant consideration. aim this study to analyze relationship between total consumption mixed flow by developing predictive model. impact pumping performance conversion for typical mixed-flow has been investigated combined approach theoretical derivation, numerical simulation, experimental verification. Validation methods was achieved comparing results experimentally obtained data. A prediction model developed head power, which incorporated prerotation. utilized mathematical simulation compute output wide range angles. two were highly consistent. Moreover, effects structure analyzed. It found that led an increase incoming angle, resulting unstable patterns causing secondary flows low-pressure vortex impeller path. This induced rise impeller. analysis internal provide foundation predicting hydraulic performances pumps under conditions improving their operation.

Language: Английский

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Determining the Head Characteristics of Radial Centrifugal Pumps under the Impact of Prewhirl

Applied Sciences, Journal Year: 2024, Volume and Issue: 14(16), P. 7224 - 7224

Published: Aug. 16, 2024

The flow rate is a significant factor in the operation of centrifugal pumps. characteristic curve pump head frequently employed calculation rate. Nevertheless, this may be subject to alteration because prewhirl on suction side pump. Calculating changes head’s reveals change hydraulic losses. impact losses investigated by experimental and numerical analysis two radial It demonstrated that primary occur impeller Relative velocity context. Alterations pumps’ configurations result range secondary flows shock at leading edge blades. A physical model, derived basis relative velocity, used predict curves pumps with high degree accuracy. results demonstrate notable enhancement comparison modelling techniques do not incorporate fluctuating

Language: Английский

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