A Method for Correlating the Characteristics of Centrifugal Pumps in Two-Phase Flow

1978 ◽  
Vol 100 (4) ◽  
pp. 395-409 ◽  
Author(s):  
Jaroslaw Mikielewicz ◽  
David Gordon Wilson ◽  
Tak-Chee Chan ◽  
Albert L. Goldfinch

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.

Mathematics ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 769 ◽  
Author(s):  
Fan Zhang ◽  
Lufeng Zhu ◽  
Ke Chen ◽  
Weicheng Yan ◽  
Desmond Appiah ◽  
...  

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.


Symmetry ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2003
Author(s):  
Chaoshou Yan ◽  
Jianfei Liu ◽  
Shuihua Zheng ◽  
Bin Huang ◽  
Jiacheng Dai

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.


Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3048 ◽  
Author(s):  
Qiaorui Si ◽  
Gérard Bois ◽  
Qifeng Jiang ◽  
Wenting He ◽  
Asad Ali ◽  
...  

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.


2014 ◽  
Vol 6 ◽  
pp. 782619 ◽  
Author(s):  
Yu-Liang Zhang ◽  
Jun-Jian Xiao ◽  
Jian-Ping Yu ◽  
Ying-Yu Ji

The transient performance of centrifugal pumps during the startup period has drawn more and more attention in recent years due to urgent engineering needs. In order to make certain the transient startup characteristics of a high specific-speed prototype centrifugal pump delivering the gas-liquid two-phase flow, the transient flows inside the pump are numerically simulated during the startup period using the dynamic slip region method in this paper. The results show that the difference in heads mainly focuses on the later stage of the startup period when the pump is used to transmit the pure water and the gas-liquid two-phase flow, respectively. The existence of the gas phase makes the head less than that of delivering pure water. The nondimensional head coefficient is very high at the very beginning of the startup period and then quickly drops to a stable value. The continuous variation of the attack angle at the leading edges of blades is the main reason for evolution of the internal flow field during the startup period.


Author(s):  
Naoki Matsushita ◽  
Satoshi Watanabe ◽  
Kusuo Okuma ◽  
Tomomichi Hasui ◽  
Akinori Furukawa

Air-water two-phase flow performance of conventional centrifugal pumps causes the impermissible head deterioration even at an inlet void fraction less than about 10%. A tandem arrangement of double rotating cascades and higher blade outlet angle more than 90° only in outer rotating cascade has been proposed as a centrifugal pump impeller with high performance in air-water two-phase flow condition. To obtain further improvement of pump performances, a diffuser cascade is installed downstream of impeller outlet. In design of air-water two-phase flow centrifugal pump in various size and operating conditions as well as in single-phase flow, similarity law of pump performances is very useful. The similarity law of impeller diameter, blade height and rotational speed is investigated for the proposed impeller in the present paper. As the results, the similarity law of impeller diameter and rotational speed is certified experimentally even in two-phase flow condition. In addition, influences of blade height on air-water two-phase flow performances indicate a little difference from the similarity law. This difference is, then, discussed by using the results of static head on the shroud wall and air behaviors in the impellers.


Processes ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1317
Author(s):  
Biaobiao Wang ◽  
Haoyang Zhang ◽  
Fanjie Deng ◽  
Chenguang Wang ◽  
Qiaorui Si

In order to study the internal flow characteristics of centrifugal pumps with a split impeller under gas-liquid mixed transportation conditions, this paper conducted a steady calculation of the flow field in the centrifugal pump under the conditions of different inlet gas volume fractions based on the Eulerian-Eulerian heterogeneous flow model, using air and water as the working media and the Schiller Nauman model for the interphase resistance. This paper takes a low specific speed centrifugal pump as the research object, through the controlling variables, using the same pump body structure and pump body geometric parameters and setting three different arrangements of long and short blades (each plan uses the same long and short blades) to explore the influence of the short blade arrangement on the low specific speed centrifugal pump performance under a gas-liquid two-phase flow. The research results show that, under pure water conditions, the reasonable arrangement of the short blade circumferential position can eliminate the hump of the centrifugal pump under low-flow conditions, can make the flow velocity in the impeller more uniform, and can optimize the performance of the pump. Under the design conditions and the gas-liquid two-phase inflow conditions, when the circumferential position of the short blades is close to the suction surface of the long blades, some of the bubbles on the suction surface of the long blade can be broken under the work of the pressure surface of the short blade and flow out of the impeller with the liquid, which improves the flow state of the flow field in the impeller.


Author(s):  
Henrique Stel ◽  
Edgar Ofuchi ◽  
Dalton Bertoldi ◽  
Moisés Marcelino Neto ◽  
Rigoberto Morales ◽  
...  

Author(s):  
Carlos Eduardo Ribeiro Santa Cruz Mendoza ◽  
Rafael Dunaiski ◽  
Edgar Ofuchi ◽  
Henrique Stel ◽  
Rigoberto Morales

Author(s):  
Lissett Barrios ◽  
Stuart Scott ◽  
Charles Deuel

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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