scholarly journals Numerical and Experimental Analysis of Influence of Impeller Structures on Slurry Pump Performance

2021 ◽  
Vol 9 ◽  
Author(s):  
Guangjie Peng ◽  
Jialin Du ◽  
Hao Chang ◽  
Qiang Chen ◽  
Jiahu Li ◽  
...  
Keyword(s):  
Energy Loss ◽  
Power Plants ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Flow Conditions ◽  
Two Phase ◽  
Fossil Energy ◽  
Pump Performance ◽  
Wear Characteristics ◽  
Edge Vortex

Slurry pump as an important equipment for transporting coal, which are widely used in power plants, mines and other fossil energy field. Therefore, the improvement of slurry pump performance can effectively reduce the energy loss of fossil energy industry. In this paper, a novel impeller with splitter blade structure was proposed, and the internal flow field of slurry pumps with different impeller structures was analyzed. Meanwhile, according to the shape and structure of the vortex in slurry pump, the vortex can be divided into leading edge vortex, trailing edge vortex and gap leakage vortex by employing the Q criterion, and the generation mechanism of each vortex and relationship between vortex strength and flow condition were analyzed. What is more, the entropy generation theory was employed to study the energy loss of slurry pump. The pressure distribution and wear characteristics of different impeller structures under two-phase flow conditions are studied. The result shows that the energy loss caused by entropy production in the slurry pump can be declined by employing the splitter blades, which can restrain the flow separation at the impeller outlet. Thus, the impeller with splitter blades not only can reduce the energy loss of the slurry pump, but also enhance the wear characteristics of impeller under two-phase flow conditions. Finally, the result can provide the guidelines for the design optimization of slurry pump.

Performance and pressure distribution changes in a centrifugal pump under two-phase flow

1998 ◽  
Vol 212 (3) ◽  
pp. 165-171 ◽  
Author(s):  
E T Pak ◽  
J C Lee
Keyword(s):  
Pressure Gradient ◽  
Pressure Distribution ◽  
Centrifugal Pump ◽  
Void Fraction ◽  
Two Phase Flow ◽  
Positive Pressure ◽  
Phase Flow ◽  
Flow Conditions ◽  
Two Phase ◽  
Pump Performance

Pump performance characteristics change drastically under two-phase flow conditions from those of single-phase flow. This is due to a change in flow characteristics in the impeller. Owing to a positive pressure gradient the air bubble moves more slowly than the water in the impeller channel, but in the suction surface region of the impeller inlet, where a negative pressure gradient prevails, the bubbles move more quickly than the water. Thus, in the space just after this region the distributions of the void fraction obtained are considerably higher and uneven. The change in the pressure distribution owing to air admission is also particularly evident in the inlet region of the impeller. These changes bring about an alteration of the whole flow pattern in the impeller and also cause a drop in pump performance. The Reynolds-averaged Navier-Stokes equations for two-phase flow in a centrifugal pump impeller are solved using a finite volume method to obtain the pressure, velocities and void fraction respectively. Good agreement is achieved when the predicted results are compared with those measured experimentally within the range of bubbly flow conditions.

On the performance of a cascade of turbine rotor tip section blading in wet steam Part 3: Wake traverses

1997 ◽  
Vol 211 (8) ◽  
pp. 639-648 ◽  
Author(s):  
F Bakhtar ◽  
H Mashmoushy ◽  
O C Jadayel
Keyword(s):  
Liquid Phase ◽  
Two Phase Flow ◽  
Turbine Rotor ◽  
Phase Flow ◽  
Wet Steam ◽  
Flow Conditions ◽  
Two Phase ◽  
Blow Down ◽  
The Third ◽  
Phase Mixture

During the course of expansion of steam in turbines the fluid first supercools and then nucleates to become a two-phase mixture. The liquid phase consists of a large number of extremely small droplets which are difficult to generate except by nucleation. To reproduce turbine two-phase flow conditions requires a supply of supercooled vapour which can be achieved under blow-down conditions by the equipment employed. This paper is the third of a set describing an investigation into the performance of a cascade of rotor tip section profiles in wet steam and presents the results of the wake traverses.

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

1993 ◽  
Vol 115 (4) ◽  
pp. 781-783 ◽  
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.

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

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.

Local characteristic of horizontal air–water two-phase flow by wire-mesh sensor

2016 ◽  
Vol 40 (3) ◽  
pp. 746-761 ◽  
Author(s):  
Weiling Liu ◽  
Chao Tan ◽  
Feng Dong
Keyword(s):  
Void Fraction ◽  
Transient Flow ◽  
Two Phase Flow ◽  
Wire Mesh ◽  
Local Characteristic ◽  
Phase Flow ◽  
Flow Conditions ◽  
Two Phase ◽  
Horizontal Pipe ◽  
Local Flow

Two-phase flow widely exists in many industries. Understanding local characteristics of two-phase flow under different flow conditions in piping systems is important to design and optimize the industrial process for higher productivity and lower cost. Air–water two-phase flow experiments were conducted with a 16×16 conductivity wire-mesh sensor (WMS) in a horizontal pipe of a multiphase flow facility. The cross-sectional void fraction time series was analysed by the probability density function (PDF), which described the void fraction fluctuation at different flow conditions. The changes and causes of PDFs during a flow regime transition were analysed. The local structure and flow behaviour were characterized by the local flow spectrum energy analysis and the local void fraction distribution (horizontal, vertical and radial direction) analysis. Finally, three-dimensional transient flow fluctuation energy evolution and characteristic scale distribution based on wavelet analysis of air–water two-phase flow were presented, which revealed the structural features of each phase in two-phase flow.

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