A study on performance of centrifugal pumps driven in two-phase flow (2nd report, Prediction of pump head)

The semiempirical method described combines the ideal performance of a centrifugal pump with experimental data for single and two-phase flow to produce a so-called “head-loss ratio,” which is the apparent loss of head in two-phase flow divided by the loss of head in single-phase flow. This head-loss ratio is shown to be primarily a function of void fraction. It is demonstrated that the measured characteristics of a centrifugal pump operating in two-phase flow in normal rotation and normal and reversed flow directions (first and second -quadrant operation) and in reversed rotation and reversed flow direction (third-quadrant operation) can be reproduced with acceptable accuracy.

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Surveillance Models of Large-Scale ESP With High Viscosity Fluids and Gas

Volume 6: Materials Technology; Polar and Arctic Sciences and Technology; Petroleum Technology Symposium ◽

10.1115/omae2012-83534 ◽

2012 ◽

Author(s):

Lissett Barrios ◽

Stuart Scott ◽

Charles Deuel

Keyword(s):

Large Scale ◽

Two Phase Flow ◽

Electrical Current ◽

High Viscosity ◽

Viscous Fluids ◽

Phase Flow ◽

Centrifugal Pumps ◽

Operational Parameters ◽

Two Phase ◽

Operational Conditions

The paper reports on developmental research on the effects of viscosity and two phases, liquid–gas fluids on ESPs which are multi stage centrifugal pumps for deep bore holes. Multiphase viscous performance in a full-scale Electrical Submersible Pump (ESP) system at Shell’s Gasmer facility has been studied experimentally and theoretically. The main objectives is to predict the operational conditions that cause degradations for high viscosity fluids when operating in high Gas Liquid Radio (GLR) wells to support operation in Shell major Projects. The system studied was a 1025 series tandem WJE 1000. The test was performed using this configuration with ten or more pump stages moving fluids with viscosity from 2 to 200 cP at various speed, intake pressure and Gas Void Fractions (GVF). For safety considerations the injected gas was restricted to nitrogen or air. The ESP system is a central artificial lift method commonly used for medium to high flow rate wells. Multiphase flow and viscous fluids causes problems in pump applications. Viscous fluids and free gas inside an ESP can cause head degradation and gas locking. Substantial attempts have been made to model centrifugal pump performance under gas-liquid viscous applications, however due to the complexity this is still a uncertain problem. The determination of the two-phase flow performance in these harmful conditions in the ESP is fundamental aspects in the surveillance operation. The testing at Shell’s Gasmer facility revealed that the ESP system performed as theoretical over the range of single flowrates and light viscosity oils up to Gas Volume Fractions (GVF) around 25%. The developed correlations predict GVF at the pump intake based on the operational parameters. ESP performance degrades at viscosity higher than 100cp as compared to light oil applications, gas lock condition is observed at gas fraction higher than 45%. Pump flowrate can be obtained from electrical current and boost for all range of GVF and speed. The main technical contributions are the analysis of pump head degradation under two important variables, high viscosity and two-phase flow inside the ESP.

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Prediction of Pump Performance Under Air-Water Two-Phase Flow Based on a Bubbly Flow Model

Journal of Fluids Engineering ◽

10.1115/1.2910213 ◽

1993 ◽

Vol 115 (4) ◽

pp. 781-783 ◽

Cited By ~ 6

Author(s):

Kiyoshi Minemura ◽

Tomomi Uchiyama

Keyword(s):

Two Phase Flow ◽

Bubbly Flow ◽

Phase Flow ◽

Centrifugal Pumps ◽

Flow Conditions ◽

Two Phase ◽

Performance Change ◽

Void Fractions ◽

Two Phases

This paper is concerned with the determination of the performance change in centrifugal pumps operating under two-phase flow conditions using the velocities and void fractions calculated under the assumption of an inviscid bubbly flow with slippage between the two phases. The estimated changes in the theoretical head are confirmed with experiments within the range of bubbly flow regime.

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Numerical Simulation of Gas–Liquid Two-Phase Flow Characteristics of Centrifugal Pump Based on the CFD–PBM

Mathematics ◽

10.3390/math8050769 ◽

2020 ◽

Vol 8 (5) ◽

pp. 769 ◽

Cited By ~ 1

Author(s):

Fan Zhang ◽

Lufeng Zhu ◽

Ke Chen ◽

Weicheng Yan ◽

Desmond Appiah ◽

...

Keyword(s):

Numerical Simulation ◽

Centrifugal Pump ◽

Two Phase Flow ◽

Average Diameter ◽

Balance Model ◽

Phase Flow ◽

Centrifugal Pumps ◽

Two Phase ◽

Coalescence Rate ◽

Breakage Rate

This work seeks to apply the computational fluid dynamics–population balance model (CFD–PBM) to investigate the gas distribution and flow mechanism in the gas–liquid two-phase flow of a centrifugal pump. The findings show that the numerical simulation accurately captures the bubble distribution characteristics in the process of coalescence and breakage evolution. In addition, comparing the CFD–PBM with the Double Euler, the hydraulic head of the pump are similar, but the efficiency using the Double Euler is much higher—even close to single-phase. This is in contrast to previous experimental research. Then, the unsteady flow usually led to the formation of bubbles with larger diameters especially where vortices existed. In addition, the rotor–stator interaction was a main reason for bubble formation. Generally, it was observed that the coalescence rate was greater than the breakage rate; thus, the coalescence rate decreased until it equaled the breakage rate. Thereafter, the average diameter of the bubble in each part tended to be stable during the process of bubble evolution. Finally, the average diameter of bubbles seemed to increase from inlet to outlet. The results of this study may not only enhance the gas–liquid two-phase internal flow theory of centrifugal pumps, but also can serve as a benchmark for optimizations of reliable operation of hydraulic pumps under gas–liquid two-phase flow conditions.

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Experimental Investigations on the Inner Flow Behavior of Centrifugal Pumps under Inlet Air-Water Two-Phase Conditions

Energies ◽

10.3390/en12224377 ◽

2019 ◽

Vol 12 (22) ◽

pp. 4377 ◽

Cited By ~ 5

Author(s):

Si ◽

Zhang ◽

Bois ◽

Zhang ◽

Cui ◽

...

Keyword(s):

Two Phase Flow ◽

Flow Behavior ◽

Bubbly Flow ◽

Performance Degradation ◽

Phase Flow ◽

Centrifugal Pumps ◽

Two Phase ◽

Impeller Blade ◽

Pump Performance ◽

Starting Point

Centrifugal pumps are widely used and are known to be sensitive to inlet air-water two-phase flow conditions. The pump performance degradation mainly depends on the changes in the two-phase flow behavior inside the pump. In the present paper, experimental overall pump performance tests were performed for two different rotational speeds and several inlet air void fractions (αi) up to pump shut-off condition. Visualizations were also performed on the flow patterns of a whole impeller passage and the volute tongue area to physically understand pump performance degradation. The results showed that liquid flow modification does not follow head modification as described by affinity laws, which are only valid for homogeneous bubbly flow regimes. Three-dimensional effects were more pronounced when inlet void fraction increased up to 3%. Bubbly flow with low mean velocities were observed close to the volute tongue for all αi, and returned back to the impeller blade passages. The starting point of pump break down was related to a strong inward reverse flow that occurred in the vicinity of the shroud gap between the impeller and volute tongue area.

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Study on the Effects of the Wear-Rings Clearance on the Solid-Liquid Two-Phase Flow Characteristics of Centrifugal Pumps

Symmetry ◽

10.3390/sym12122003 ◽

2020 ◽

Vol 12 (12) ◽

pp. 2003

Author(s):

Chaoshou Yan ◽

Jianfei Liu ◽

Shuihua Zheng ◽

Bin Huang ◽

Jiacheng Dai

Keyword(s):

Numerical Simulation ◽

Centrifugal Pump ◽

Two Phase Flow ◽

Phase Flow ◽

Centrifugal Pumps ◽

Suction Surface ◽

Two Phase ◽

Wear Area ◽

Fluid Medium ◽

Solid Liquid

In order to study the wear law of the centrifugal pump flowing surface under different wear-rings clearance, the McLaury wear model was used to conduct the full-passage numerical simulation of solid-liquid two-phase flow in a single-stage single-suction centrifugal pump. The reliability of the numerical calculation method is verified by comparing the experimental data and numerical simulation results. The clearance is 0.1, 0.15, 0.2, 0.3 and 0.5 mm, respectively. The results show that the wear of the centrifugal pump blades is mainly concentrated in the end part and the inlet part of the blade, and the wear of the pressure surface at the end of the suction surface and the front of the blade is more serious. As the clearance increases, the maximum wear value in the impeller increases first and then decreases, reaching a maximum at 0.15 mm. With the increase of the clearance, the wear degree and the wear rate of the volute wall surface first increase and then decrease, and reach the maximum at 0.2 mm. With the increase of the clearance and the concentration of the fluid medium, the wear at the clearance of the centrifugal pump is more serious, and the severe wear area exhibits a point-like circumferential distribution.

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Investigation on the Handling Ability of Centrifugal Pumps under Air–Water Two-Phase Inflow: Model and Experimental Validation

Energies ◽

10.3390/en11113048 ◽

2018 ◽

Vol 11 (11) ◽

pp. 3048 ◽

Cited By ~ 9

Author(s):

Qiaorui Si ◽

Gérard Bois ◽

Qifeng Jiang ◽

Wenting He ◽

Asad Ali ◽

...

Keyword(s):

Centrifugal Pump ◽

Two Phase Flow ◽

Bubbly Flow ◽

Three Dimensional ◽

Navier Stokes ◽

Phase Flow ◽

Centrifugal Pumps ◽

Flow Conditions ◽

Two Phase ◽

Local Flow

The paper presents experimental and numerical investigations performed on a single stage, single-suction, horizontal-orientated centrifugal pump in air–water two-phase non-condensable flow conditions. Experimental measurements are performed in a centrifugal pump using pressure sensor devices in order to measure the wall static pressures at the inlet and outlet pump sections for different flow rates and rotational speeds combined with several air void fraction (a) values. Two different approaches are used in order to predict the pump performance degradations and perform comparisons with experiments for two-phase flow conditions: a one-dimensional two-phase bubbly flow model, and a full “Three-Dimensional Unsteady Reynolds Average Navier–Stokes” (3D-URANS) simulation using a modified k-epsilon turbulence model combined with the Euler–Euler inhomogeneous two-phase flow description. The overall and local flow features are presented and analyzed. Limitations concerning both approaches are pointed out according to some flow physical assumptions and measurement accuracies. Some additional suggestions are proposed in order to improve two-phase flow pump suction capabilities.

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A Comparative Study on Centrifugal Pump Designs and Two-Phase Flow Characteristic under Inlet Gas Entrainment Conditions

Energies ◽

10.3390/en13010065 ◽

2019 ◽

Vol 13 (1) ◽

pp. 65 ◽

Cited By ~ 6

Author(s):

Qiaorui Si ◽

Gérard Bois ◽

Minquan Liao ◽

Haoyang Zhang ◽

Qianglei Cui ◽

...

Keyword(s):

Pressure Pulsation ◽

Two Phase Flow ◽

Three Dimensional ◽

Flow Characteristics ◽

Internal Flow ◽

Phase Flow ◽

Water Mixture ◽

Centrifugal Pumps ◽

Two Phase ◽

Void Fractions

Capability for handling entrained gas is an important design consideration for centrifugal pumps used in petroleum, chemistry, nuclear applications. An experimental evaluation on their two phase performance is presented for two centrifugal pumps working under air-water mixture fluid conditions. The geometries of the two pumps are designed for the same flow rate and shut off head coefficient with the same impeller rotational speed. Overal pump performance and unsteady pressure pulsation information are obtained at different rotational speeds combined with various inlet air void fractions (α0) up to pump stop condition. As seen from the test results, pump 2 is able to deliver up to 10% two-phase mixtures before pump shut-off, whereas pump 1 is limited to 8%. In order to understand the physics of this flow phenomenon, a full three-dimensional unsteady Reynolds Average Navier-Stokes (3D-URANS) calculation using the Euler–Euler inhomogeneous method are carried out to study the two phase flow characteristics of the model pump after corresponding experimental verification. The internal flow characteristics inside the impeller and volute are physically described using the obtained air distribution, velocity streamline, vortex pattern and pressure pulsation results under different flow rates and inlet void fractions. Pump performances would deteriorate during pumping two-phase mixture fluid compared with single flow conditions due to the phase separating effect. Some physical explanation about performance improvements on handing maximum acceptable inlet two phase void fractions capability of centrifugal pumps are given.

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Performance prediction model of multistage centrifugal Pumps used as Turbines with Two-Phase Flow

Energy Procedia ◽

10.1016/j.egypro.2018.08.102 ◽

2018 ◽

Vol 148 ◽

pp. 408-415 ◽

Cited By ~ 7

Author(s):

M. Stefanizzi ◽

M. Torresi ◽

F. Fornarelli ◽

B. Fortunato ◽

S.M. Camporeale

Keyword(s):

Prediction Model ◽

Performance Prediction ◽

Two Phase Flow ◽

Phase Flow ◽

Centrifugal Pumps ◽

Two Phase

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Investigation of Centrifugal Pump Performance Under Two-Phase Flow Conditions

Journal of Fluids Engineering ◽

10.1115/1.2816802 ◽

1995 ◽

Vol 117 (1) ◽

pp. 129-137 ◽

Cited By ~ 15

Author(s):

G. R. Noghrehkar ◽

M. Kawaji ◽

A. M. C. Chan ◽

H. Nakamura ◽

Y. Kukita

Keyword(s):

Centrifugal Pump ◽

Nuclear Reactor ◽

Two Phase Flow ◽

Fluid Model ◽

Small Scale ◽

Phase Flow ◽

Flow Conditions ◽

Two Phase ◽

Pump Impeller ◽

Pump Head

A one-dimensional two-fluid model has been used to study the centrifugal pump head degradation phenomena and to analyze the gas-liquid interaction within the pump impeller under high pressure, steam-water two-phase flow conditions. The analytical model was used to predict the two-phase pump head data for the small-scale and full-scale nuclear reactor pumps and the predictions of the head degradation compared favorably with the test data for different suction void fractions. The physical mechanisms responsible for head degradation were also investigated.

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