Performance Predication and Axial Force Study on Deep-Well Centrifugal Pump

2011 ◽  
Vol 130-134 ◽  
pp. 711-714
Author(s):  
Ling Zhou ◽  
Wei Dong Shi ◽  
Wei Gang Lu ◽  
Hui Li
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Pump ◽  
Axial Force ◽  
Simulation Method ◽  
Experimental Measurements ◽  
Centrifugal Pumps ◽  
Pump Performance ◽  
Deep Well ◽  
Multi Stage ◽  
Safety And Reliability

Axial force is one of the main factors which affect the pump safety and reliability during the operation of pumps, especially in multi-stage centrifugal pumps. 150QJ20 type deep-well centrifugal pump (DCP) is selected as an example to research the pump performance and axial force with the numerical simulation and experiment method. The numerical simulation results were compared with experimental measurements, and such result was analyzed. The results show that the change trend of the pump performance and axial force acquired by numerical and experiment is similar. At rated operating point, the error of axial force between the numerical simulation and experimental measurements is less than 3%. This confirmed the feasibility of predict the pump performance by numerical simulation method.

scholarly journals NUMERICAL CALCULATION AND EXPERIMENTAL STUDY OF AXIAL FORCE IN A DEEP-WELL CENTRIFUGAL PUMP

2014 ◽  
Vol 44 (1) ◽  
pp. 105-110
Author(s):  
L. ZHOU ◽  
W. D. SHI ◽  
L. BAI ◽  
W. G. LU ◽  
W. LI
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Pump ◽  
Axial Force ◽  
Experimental Results ◽  
Centrifugal Impeller ◽  
Centrifugal Pumps ◽  
Deep Well ◽  
Multi Stage ◽  
Operation Process ◽  
Force Calculation

 In the operation process of centrifugal pumps, especially in multi-stage pumps, axial force is one of the main factors which affect the pump safety and reliability. This paper presents the axial force study in a deep-well centrifugal pump (DCP) with theoretical calculation, numerical simulation and experimental measure. Three different calculation formulas were respectively introduced and used in the model pump. The calculated results were compared and analyzed with the numerical simulation values and experimental results, and the detailed numerical simulation methods and experimental configuration were explained. Finally, the more accurate formula for calculating the axial force in oblique flow centrifugal impeller was selected out. At the rated flow point, the deviation of the axial force obtained by numerical simulation and the experimental value is approximately 3.8%, and the calculated result of selected formula only less than the experimental results of 2.6%. The results provide a theoretical basis for the axial force calculation in the centrifugal impeller design process.

Numerical Simulation and Experimental Study on Deep-Well Centrifugal Pump with Small Rear Shroud Diameter

2011 ◽  
Vol 354-355 ◽  
pp. 659-663
Author(s):  
Wei Dong Shi ◽  
Ling Zhou ◽  
Wei Gang Lu ◽  
Hui Li
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Pump ◽  
Axial Force ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Pump Impeller ◽  
Pump Performance ◽  
Deep Well ◽  
Static Pressure Distribution

Choose the appropriate rear shroud diameter of impeller could get relatively small axial force and high pump performance. In this paper, a deep-well centrifugal pump impeller with a small rear shroud was studied by simulation and test. Two stages deep well centrifugal pump was simulated by means of a commercial CFD software that solved the Navier-Stokes equations for three-dimensional steady flow. The flow field and the static pressure distribution in the impellers obtained by steady numerical simulation were analyzed. By manufacturing and testing, the test results was acquired, and then compared with the predicting data of the numerical simulation. Results show that trimming the rear shroud could reduce the axial force, but too small rear shroud diameter lead to pump performance decline.

Numerical and Experimental Study of Axial Force and Hydraulic Performance in a Deep-Well Centrifugal Pump With Different Impeller Rear Shroud Radius

2013 ◽  
Vol 135 (10) ◽  
Author(s):  
Ling Zhou ◽  
Weidong Shi ◽  
Wei Li ◽  
Ramesh Agarwal
Keyword(s):  
Centrifugal Pump ◽  
Axial Force ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Hydraulic Performance ◽  
Navier Stokes ◽  
Computational Domain ◽  
Pump Performance ◽  
Deep Well ◽  
Static Pressure Distribution

A multistage deep-well centrifugal pump (DCP) with different impeller rear shroud radius have been investigated both numerically and experimentally under multiconditons, which aims at studying the influence of impeller rear shroud radius to the axial force and pump hydraulic performance. During this study, a two-stage DCP equipped with three different impellers was simulated employing the commercial computational fluid dynamics (CFD) software ANYSY-Fluent to solve the Navier-Stokes equations for three-dimensional steady flow. High-quality structured grids were meshed on the whole computational domain. Test results were acquired by prototype experiments, and then compared with the predicted pump performance and axial force. The static pressure distribution in the pump passage obtained by numerical simulation was analyzed. The results indicated that the appropriate impeller rear shroud radius could improve the pump performance and lower the axial force significantly.

Study of the Effect of Impeller Side Clearance on the Centrifugal Pump Performance Using CFD

2015 ◽  
Author(s):  
A. Farid Ayad ◽  
H. M. Abdalla ◽  
A. Abou El-Azm
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Pump ◽  
Reference Frame ◽  
Internal Flow ◽  
Computational Domain ◽  
Performance Parameters ◽  
Centrifugal Pumps ◽  
Empirical Formulas ◽  
Pump Performance ◽  
The Impact

Centrifugal pumps (CP) are probably among the most often used machinery in industrial facilities as well as in common practice. Compared to other types of rotating pumps, CP yield higher efficiency. In aerospace application reducing the weight of the CP impeller has the advantage of reducing mechanical stresses and enable using the CP at high number of revolution. In order to minimize the impeller weight the requirements to study and develop the CP with semi-open impeller appears. Using this type of impeller results in clearance between the impeller blades and the casing which degrade the centrifugal pump performance. The impact of this side clearance has not been deeply investigated in open literature. The present paper is devoted to reveal more details about the impact of CP side clearance on its performance. This is done by numerically investigating the influence of the variation of the CP side clearance width (0:0.2 impeller width) on the CP performance parameters at different flow rates (0:5 Liter/s). These CP performance parameters include the pump head, efficiency, slip factor, blades loads and the internal flow structure. 3-D steady numerical simulation has been carried out using commercial software, ANSYS® CFX. The computational domain consists of four zones: inlet, side gab, impeller and volute with outlet. They are defined by means of the multi-reference frame technique. The impeller is situated in the rotating reference frame, while the inlet, side gab and outlet zones are in the fixed reference frame, and they are related to each other through the “frozen rotor” interface. The meshes of four computational domains are generated separately after performing mesh sensitivity analysis. The boundary conditions are set as total pressure at inlet and the mass flow at outlet. A no-slip condition is imposed at the wall boundary defined at the blade and casing. A turbulent, incompressible flow solver has been adapted using SST k–ω turbulent model. The numerical simulation has been compared with own experimental results and a published empirical formulas to verify the numerical solution. The CFD results show an acceptable agreement with the results of the experimental work and the empirical formulas. It has been shown that the impeller side clearance have a great regression effect on the centrifugal pump performance. An explanation to the performance regression has been proposed based on the flow field feature. Performance regression could be attributed to the drop in the pressure difference between the impeller inlet and outlet. And the redistribution of the velocity inside the impeller channel and the side clearance.

scholarly journals Particle Distribution and Motion in Six-Stage Centrifugal Pump by Means of Slurry Experiment and CFD-DEM Simulation

2021 ◽  
Vol 9 (7) ◽  
pp. 716
Author(s):  
Liwen Deng ◽  
Qiong Hu ◽  
Jun Chen ◽  
Yajuan Kang ◽  
Shaojun Liu
Keyword(s):  
Centrifugal Pump ◽  
Simulation Method ◽  
Test Site ◽  
Centrifugal Pumps ◽  
Mining System ◽  
Transport Characteristic ◽  
Dem Simulation ◽  
Multi Stage ◽  
Pump Stage ◽  
Slurry Transport

Six-stage centrifugal pumps are used in deep-sea mining lifting systems and are required to convey slurry containing coarse particles. A six-stage centrifugal pump suitable for operation in a natural mining system was manufactured. High-flow and full-scaled slurry conveying experiments at a 5% and 9% volume concentration of particles was carried out at a large modified test site with artificial nodules. CFD-DEM simulations were carried out to obtain slurry transport characteristic curves, particle transport and distribution characteristics, where the simulation method was validated by the experiment data. A clarified two-stage pump can be used instead of a multi-stage pump for simplified simulation calculations with acceptable accuracy. Local agglomeration of particles caused by backflow was found at the outlet of the diffuser, and such agglomeration decreased with increasing flow rates. It was found that particles are transported non-uniformly, particles transport in diffusers in strands. Particles are transported in a pulse-like mode within the pump, with the latter stage showing similar particle characteristics to those transported in the previous pump stage.

Enhancing the Performance of Centrifugal Pump by Adding Cylindrical Disks at Inlet Suction

2019 ◽  
Author(s):  
Linda Sadik ◽  
Badih Jawad ◽  
Munther Y. Hermez ◽  
Liping Liu
Keyword(s):  
Numerical Simulation ◽  
Secondary Flow ◽  
Centrifugal Pump ◽  
Three Dimensional ◽  
Low Flow ◽  
Pump Efficiency ◽  
Centrifugal Pumps ◽  
Flow Rates ◽  
Pump Performance ◽  
Suction Performance

Abstract Optimizing the high efficiency design of centrifugal pumps requires a detailed understanding of the internal flow. The prediction of the flow inside the pump can be acquired by understanding the rotatory motion and the three-dimensional shape of the impellers, as well as its fundamental unsteady behavior. The flow inside a centrifugal pump is three-dimensional, unsettled and always associated with secondary flow structures. When a centrifugal pump operates under low flow rates, a secondary flow, known as recirculation, starts to begin. Inside this, the separation of flow increases, which creates vortices and cause local pressure to decrease, which induces cavitation. This phenomenon of recirculation will increase the Net Positive Suction Head Required (NPSHR). Improving the suction performance continues to remain a vital and continuous topic in the development and application of centrifugal pumps. In this research, the focal point is to enhance the pump suction performance under low flow rates by modifying the impeller design. This research entails a numerical simulation investigation on the addition of three different designs, each consisting of two cylindrical disks at the impeller inlet suction. It is hypothesized that these modifications will assist suppressing the recirculation phenomenon. The turbulent flow within the centrifugal pump was analyzed by applying the Reynolds-Averaged Navier-Stokes equations and the k–ϵ equations for turbulence modelling. The computational domain consists of the inlet, impeller, diffuser and outlet. Analysis of ΔP, torque data and pump efficiency was conducted. The application of CFD solvers to predict pump performance resulted in reduced prices for testing as well as pump development time. The numerical simulation concluded that placing 3-D multi-cylindrical disks at the impeller inlet section improved the centrifugal pump performance under low flow rates. The model design 1 resulted in a pump efficiency improvement of about 5% at low flow rates by lowering the amount of flow leaking back (re-circulation) through the internal suction.

scholarly journals Optimal Design of Slit Impeller for Low Specific Speed Centrifugal Pump Based on Orthogonal Test

2021 ◽  
Vol 9 (2) ◽  
pp. 121
Author(s):  
Yang Yang ◽  
Ling Zhou ◽  
Hongtao Zhou ◽  
Wanning Lv ◽  
Jian Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Pump ◽  
Large Scale ◽  
Internal Flow ◽  
Orthogonal Test ◽  
Centrifugal Pumps ◽  
Initial Model ◽  
Low Specific Speed ◽  
Specific Speed ◽  
Four Levels

Marine centrifugal pumps are mostly used on board ship, for transferring liquid from one point to another. Based on the combination of orthogonal testing and numerical simulation, this paper optimizes the structure of a drainage trough for a typical low-specific speed centrifugal pump, determines the priority of the various geometric factors of the drainage trough on the pump performance, and obtains the optimal impeller drainage trough scheme. The influence of drainage tank structure on the internal flow of a low-specific speed centrifugal pump is also analyzed. First, based on the experimental validation of the initial model, it is determined that the numerical simulation method used in this paper is highly accurate in predicting the performance of low-specific speed centrifugal pumps. Secondly, based on the three factors and four levels of the impeller drainage trough in the orthogonal test, the orthogonal test plan is determined and the orthogonal test results are analyzed. This work found that slit diameter and slit width have a large impact on the performance of low-specific speed centrifugal pumps, while long and short vane lap lengths have less impact. Finally, we compared the internal flow distribution between the initial model and the optimized model, and found that the slit structure could effectively reduce the pressure difference between the suction side and the pressure side of the blade. By weakening the large-scale vortex in the flow path and reducing the hydraulic losses, the drainage trough impellers obtained based on orthogonal tests can significantly improve the hydraulic efficiency of low-specific speed centrifugal pumps.

scholarly journals Investigation on centrifugal pump performance degradation under air-water inlet two-phase flow conditions

2018 ◽  
pp. 41-48 ◽  
Author(s):  
Qiaorui Si ◽  
Qianglei Cui ◽  
Keyu Zhang ◽  
Jianping Yuan ◽  
Gérard Bois
Keyword(s):  
Centrifugal Pump ◽  
Pressure Pulsation ◽  
Flow Characteristics ◽  
Performance Degradation ◽  
Inlet Pressure ◽  
Pulsation Frequency ◽  
Centrifugal Pumps ◽  
Two Phase ◽  
Flow Rates ◽  
Pump Performance

In order to study the flow characteristics of centrifugal pumps when transporting the gas-liquid mixture, water and air were chosen as the working medium. Both numerical simulation and experimental tests were conducted on a centrifugal pump under different conditions of inlet air volume fraction (IAVF). The calculation used URANS k-epsilon turbulence model combined with the Euler-Euler inhomogeneous two-phase model. The air distribution and velocity streamline inside the impeller were obtained to discuss the flow characteristics of the pump. The results show that air concentration is high at the inlet pressure side of the blade, where the vortex will exist, indicating that the gas concentration have a great relationship with the vortex aggregation in the impeller passages. In the experimental works, pump performances were measured at different IAVF and compared with numerical results. Contributions to the centrifugal pump performance degradations were analyzed under different air-water inlet flow condition such as IAVF, bubble size, inlet pressure. Results show that pump performance degradation is more pronounced for low flow rates compared to high flow rates. Finally, pressure pulsation and vibration experiments of the pump model under different IAVF were also conducted. Inlet and outlet transient pressure signals under four IAVF were investigated and pressure pulsation frequency of the monitors is near the blade passing frequency at different IAVF, and when IAVF increased, the lower frequency signal is more and more obvious. Vibration signals at five measuring points were also obtained under different IAVF for various flow rates.

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

Mathematics ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 769 ◽  
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.

scholarly journals Experimental Investigation and Passive Flow Control of a Cavitating Centrifugal Pump

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Spyridon D. Kyparissis ◽  
Dionissios P. Margaris
Keyword(s):  
Flow Control ◽  
Centrifugal Pump ◽  
Leading Edge ◽  
Total Efficiency ◽  
Centrifugal Pumps ◽  
Pump Performance ◽  
Passive Flow Control ◽  
Passive Flow ◽  
Pump Test ◽  
Blade Leading Edge

Passive flow control techniques are used to improve the flow field and efficiency of centrifugal pumps and turbomachines, in general. An important phenomenon that mechanical engineers have to take into account is cavitation. It leads to the decrease of the pump performance and total head. In the present experimental study, a centrifugal pump is investigated in cavitating conditions. A passive flow control is realized using three different blade leading edge angles in order to reduce the cavitation development and enhance the pump performance. The experiments are carried out in a pump test rig specially designed and constructed, along with the impellers. The head drop and total efficiency curves are presented in order to examine the effect of the blade leading edge angle on the cavitation and pump performance. Finally, the vapour distribution along with the blades is illustrated for the tested blade leading edge angles.

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