Advanced Image Analysis of Two-Phase Flow inside a Centrifugal Pump

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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Calculating Method for the Solid Phase Effect Coefficient of the Solid-Fluid Two Phase Flow Centrifugal Pump

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.29-32.658 ◽

2010 ◽

Vol 29-32 ◽

pp. 658-663

Author(s):

Chuan Jun Li ◽

Gang Yu ◽

Xin Wang

Keyword(s):

Differential Equation ◽

Centrifugal Pump ◽

Two Phase Flow ◽

Solid Phase ◽

High Accuracy ◽

Phase Flow ◽

Phase Effect ◽

Two Phase ◽

Error Band ◽

Calculating Method

In order to acquire the solid-fluid two phase flow centrifugal pump’s slurry head according with the fact, the solid phase effect coefficient must be calculated precisely. By analysising the acting forces on the solid particle, its moving differential equation was established. And the calculating formula of the solid phase effect coefficient was deduced based on the equation. For the sake of verifying its validity, a test of contrast and comparison on the calculating slurry heads by some ways was carried out. The results shows that the relative error values of the slurry head calculated are less than 2.00% with a small and stably error band. The method has the advantage of simple calculating process, high accuracy, low randomness and good practicability.

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Wear Characteristics of Dense Fine Particles Solid-Liquid Two-Phase Fluid Centrifugal Pump with Open Impellers

Shock and Vibration ◽

10.1155/2021/6635630 ◽

2021 ◽

Vol 2021 ◽

pp. 1-13

Author(s):

Yanping Wang ◽

Chuanfeng Han ◽

Ye Zhou ◽

Zhe Lin ◽

Jianfeng Ma ◽

...

Keyword(s):

Numerical Simulation ◽

Centrifugal Pump ◽

Volume Concentration ◽

Fine Particles ◽

Two Phase Flow ◽

Middle Part ◽

Phase Flow ◽

Particle Volume ◽

Two Phase ◽

Wear Characteristics

The demand for a centrifugal pump with open impellers for conveying dense fine particles in solid-liquid two-phase flow has increased significantly in actual engineering. The wear of dense fine particles on the centrifugal pump is also exceedingly prominent, which affects the engineering efficiency and economic benefits. The two-phase flow in the open centrifugal pump is three-dimensional and unsteady; the movement of high-volume concentration particles in the centrifugal pump and its mutual influence on the two-phase flow, which results in the calculation of wear, are very intricate. To study the wear characteristics of the centrifugal pump with open impeller with high-volume concentration particles more accurately, numerical simulation and experimental comparison are carried out for the impeller wear of dense fine particles transported by the centrifugal pump with open impellers. Considering the relationship between particles and walls, we used the Fluent 18.0 built-in rebound function and wear model. The RNG k-ε model and the DDPM model were adopted in the numerical simulation, and the numerical solution for centrifugal pump wear was performed under flow rate (9.6 m3·h−1, 12.8 m3·h−1, 16 m3·h−1, and 19.2 m3·h−1), different particle sizes (0.048 mm, 0.106 mm, 0.15 mm, 0.27 mm, and 0.425 mm), and different particle volume concentrations (10%, 15%, 20%, 25%, and 30%), respectively. By comparing the serious wear positions of the impeller, the experimental results correspond well with the numerical simulation, which can be used to predict and study the wear characteristics of the impeller. The results show that the most serious area of blade wear is the middle part of the pressure surface, followed by the middle part of the upper part of the blade. The wear of the impeller is greatly affected by relevant parameters, such as pump flow rate, particle diameter, and particle volume concentration. These results can provide some basis for the wear-resistant design of dense fine particle impeller.

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Numerical Study on the Gas-Water Two-Phase Flow in the Self-Priming Process of Self-Priming Centrifugal Pump

Processes ◽

10.3390/pr7060330 ◽

2019 ◽

Vol 7 (6) ◽

pp. 330 ◽

Cited By ~ 34

Author(s):

Chuan Wang ◽

Bo Hu ◽

Yong Zhu ◽

Xiuli Wang ◽

Can Luo ◽

...

Keyword(s):

Centrifugal Pump ◽

Two Phase Flow ◽

Numerical Study ◽

The Self ◽

Main Stage ◽

Phase Flow ◽

Urban Greening ◽

Two Phase ◽

Ansys Cfx ◽

Priming Process

A self-priming centrifugal pump can be used in various areas such as agricultural irrigation, urban greening, and building water-supply. In order to simulate the gas-water two-phase flow in the self-priming process of a self-priming centrifugal pump, the unsteady numerical calculation of a typical self-priming centrifugal pump was performed using the ANSYS Computational Fluid X (ANSYS CFX) software. It was found that the whole self-priming process of a self-priming pump can be divided into three stages: the initial self-priming stage, the middle self-priming stage, and the final self-priming stage. Moreover, the self-priming time of the initial and final self-priming stages accounts for a small percentage of the whole self-priming process, while the middle self-priming stage is the main stage in the self-priming process and further determines the length of the self-priming time.

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Influences of Impeller Diameter and Diffuser Blades on Air-Water Two-Phase Flow Performance of Centrifugal Pump

Volume 2: Fora ◽

10.1115/fedsm2005-77388 ◽

2005 ◽

Cited By ~ 2

Author(s):

Naoki Matsushita ◽

Akinori Furukawa ◽

Kusuo Okuma ◽

Satoshi Watanabe

Keyword(s):

Centrifugal Pump ◽

Water Flow ◽

Flow Rate ◽

Rotational Speed ◽

Flow Condition ◽

High Performance ◽

Two Phase Flow ◽

Water Flow Rate ◽

Phase Flow ◽

Two Phase

A tandem arrangement of double rotating cascades and single diffuser cascade, proposed as a centrifugal pump with high performance in air-water two-phase flow condition, yields lower head due to the smallness of the impeller outlet in comparison with a impeller with large outlet diameter and no diffuser. Influences of impeller diameter change and installation of diffuser blades on two-phase flow performance were experimentally investigated under the case of the same volute casing. As the result, the similarity law of the diameter of impeller having the similar blade geometry and the rotational speed is satisfied even in two-phase flow condition. Comparing pump performances between a large impeller without diffuser blades and a small one with diffuser blades, higher two-phase flow performance is obtained by controlling the rotational speed of a small impeller with diffuser blades in the range of small water flow rates, while a large impeller with no diffuser gives high performance in the range of high water flow rate and small air flow rate.

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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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