Hydrodynamic Characteristics of Vaned-Diffuser and Return-Channel for a Multistage Centrifugal Pump

2011 ◽  
Vol 14 (6) ◽  
pp. 54-60 ◽  
Author(s):  
Hyoung-Woo Oh
Keyword(s):  
Centrifugal Pump ◽  
Hydrodynamic Characteristics ◽  
Vaned Diffuser ◽  
Multistage Centrifugal Pump ◽  
Return Channel

A New Method to Simulate Rotor-Stator Interactions in a Centrifugal Pump Stage

2006 ◽  
Author(s):  
Jianjun Feng ◽  
Friedrich-Karl Benra ◽  
Hans Josef Dohmen
Keyword(s):  
Boundary Conditions ◽  
Centrifugal Pump ◽  
Mass Flow ◽  
New Method ◽  
Water Tank ◽  
Mean Flow ◽  
Vaned Diffuser ◽  
Stationary Boundary ◽  
Flow Fluctuation ◽  
Return Channel

A new method is put forward to model rotor-stator interactions in the first stage of a multistage centrifugal pump consisting of an impeller, a vaned diffuser and a vaned return channel. A directional loss model is utilized to model the function of a water tank behind the return channel. A periodic boundary condition between the inlet and the outlet is applied to model a closed loop. Thus no flow specification either in the inlet or outlet is required, neither is the turbulence level. Consequently it can avoid specifying unphysical stationary boundary conditions at the inlet and the outlet for transient simulations. Transient numerical results are compared with those by the conventional simulation with stationary boundary conditions (constant total pressure at the inlet and fixed mass flow at the outlet) in detail. The new model can predict the mass flow fluctuation in the pump, which reaches 0.5% of mean flow rate during one period. The mass flow fluctuation does not have a significant influence on the velocity field; however it does have some important effects on the pressure and turbulent kinetic energy fields.

scholarly journals Flow Field Analysis and Feasibility Study of a Multistage Centrifugal Pump Designed for Low-Viscous Fluids

2021 ◽  
Vol 11 (3) ◽  
pp. 1314
Author(s):  
Mohamed Murshid Shamsuddeen ◽  
Sang-Bum Ma ◽  
Sung Kim ◽  
Ji-Hoon Yoon ◽  
Kwang-Hee Lee ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
Flow Behavior ◽  
Field Analysis ◽  
Low Flow ◽  
Design Stage ◽  
Pump Design ◽  
Second Stage ◽  
Low Viscosity ◽  
Multistage Centrifugal Pump ◽  
Return Channel

A multistage centrifugal pump is designed for pumping low-viscosity, highly volatile and flammable chemicals, including hydrocarbons, for high head requirements. The five-stage centrifugal pump consists of a double-suction impeller at the first stage followed by a twin volute. The impellers for stages two through five are single-suction impellers followed by diffuser vanes and return channel vanes. The analytical performance is calculated initially in the design stage by applying similarity laws to an existing scaled-down pump model designed for low flow rate applications. The proposed pump design is investigated using computational fluid dynamics tools to study its performance in design and off-design conditions for water as the base fluid. The design feasibility of the centrifugal pump is tested for other fluids, such as water at a high temperature and pressure, diesel and debutanized diesel. The pump design is found to be suitable for a variety of fluids and operating ranges. The losses in the pump are analyzed in each stage at the best efficiency point. The losses in efficiency and head are observed to be higher in the second stage than in other stages. The detailed flow behavior at the second stage is studied to identify the root cause of the losses. Design modifications are recommended to diminish the losses and improve the overall performance of the pump.

scholarly journals Vibration in a Multistage Centrifugal Pump under Varied Conditions

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Ling Bai ◽  
Ling Zhou ◽  
Xiaoping Jiang ◽  
Qinglong Pang ◽  
Daoxing Ye
Keyword(s):  
Centrifugal Pump ◽  
Vibration Frequency ◽  
Vibration Velocity ◽  
Major Type ◽  
Outlet Section ◽  
Flow Conditions ◽  
Technical Requirements ◽  
Mass Unbalance ◽  
Blade Passing Frequency ◽  
Multistage Centrifugal Pump

Multistage pumps are intended to improve designs with low-vibration and -noise features as the industry applications increase the technical requirements. In this frame, it becomes really important to fully understand the vibration patterns of these kinds of complex machines. In this study, a vibration test bench was established to examine the vibration and stability of a cantilever multistage centrifugal pump under different flow rates. The vibration spectrum diagrams for the inlet and outlet sections and the pump body were evaluated under varied flow conditions. Results showed the effects of operational conditions on the vibration of the cantilever multistage centrifugal pump. Vibration velocity was primarily caused by mass unbalance at the shut-off flow rate point. Under different flow conditions, the blade passing frequency (BPF) and two times the blade passing frequency (2BPF) were the main excitation frequencies. The vibration frequency of the final pump body remained at the BPF under different flow conditions due to the contact with the outlet section. The major type of vibration frequency for the inlet and outlet was high frequency.

scholarly journals Experimental Analysis on Pressure Fluctuation Characteristics of a Centrifugal Pump with Vaned-Diffuser

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 126
Author(s):  
Houlin Liu ◽  
Ruichao Xia ◽  
Kai Wang ◽  
Yucheng Jing ◽  
Xianghui He
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Pressure Fluctuation ◽  
Dominant Frequency ◽  
Design Flow ◽  
Signal Source ◽  
Vaned Diffuser ◽  
Impeller Outlet ◽  
Variation Tendency ◽  
Design Flow Rate

Experimental measurements to analyze the pressure fluctuation performance of a centrifugal pump with a vaned-diffuser, which its specific speed is 190. Results indicate that the main cause of pressure fluctuation is the rotor-stator interference at the impeller outlet. The head of the pump with vaned-diffuser at the design flow rate is 15.03 m, and the efficiency of the pump with a vaned-diffuser at the design flow rate reaches 71.47%. Pressure fluctuation decreases gradually with increasing distance from the impeller outlet. Along with the increase of the flow rate, amplitude of pressure fluctuation decreases. The amplitude of pressure fluctuation at the measuring points near the diffusion section of the pump body is larger than other measuring points. The variation tendency of pressure fluctuation at P1–P10 is the same, while there are wide frequency bands with different frequencies. The dominant frequency of pressure fluctuation is the blade passing frequency. The rotor-stator interference between the impeller and the vaned-diffuser gives rise to the main signal source of pressure fluctuation.

Numerical Research of the Effect of the Outlet Diameter of Diffuser on the Performance and the Radial Force in a Single-Stage Centrifugal Pump

2014 ◽  
Author(s):  
Jiang Wei ◽  
Li Guojun ◽  
Liu Pengfei ◽  
Zhang Lisheng ◽  
Qing Hongyang
Keyword(s):  
Centrifugal Pump ◽  
Radial Force ◽  
Numerical Results ◽  
Operating Conditions ◽  
Single Stage ◽  
Navier Stokes ◽  
Computational Domain ◽  
Ansys Fluent ◽  
Vaned Diffuser ◽  
Unsteady Numerical Simulation

In this paper, a single-stage pump with diffuser vanes of different outlet diameters has been investigated both numerically and experimentally. The influence of the diffuser vane outlet diameter on pump hydraulic performance and on the radial force of the impeller is explored. Pumps equipped with three different diffusers but with impellers and volutes of the same parameters were simulated by 3D Navier-Stokes solver ANSYS-FLUENT in order to study the effect of the outlet diameter of vaned diffuser on performance of the centrifugal pump. Structured grids of high quality were applied on the whole computational domain. Experimental results were acquired by prototype experiments and were then compared with the numerical results. Both experimental and numerical results show that the performance of a pump with a diffuser of smaller outlet diameter is better than of bigger outlet diameter under all operating conditions. The radial force imposed on the impeller obtained by unsteady numerical simulation was analyzed. The results also indicated that an appropriate decrease in the outlet diameter of the diffuser vane could increase the radial force.

scholarly journals Efficiency improvement and evaluation of a centrifugal pump with vaned diffuser

2019 ◽  
Vol 11 (3) ◽  
pp. 168781401982590 ◽  
Author(s):  
Kai Wang ◽  
Yu-cheng Jing ◽  
Xiang-hui He ◽  
Hou-lin Liu
Keyword(s):  
Centrifugal Pump ◽  
Axial Force ◽  
Flow Rate ◽  
Pressure Pulsation ◽  
Energy Performance ◽  
Radial Force ◽  
Design Flow ◽  
Vaned Diffuser ◽  
Original Scheme ◽  
Design Flow Rate

In order to enhance the efficiency of centrifugal pump, the structure of a centrifugal pump with vaned diffuser, whose specific speed is 190, was numerically improved by trimming back-blades of impeller and smoothing sharp corner in annular chamber. The energy performance, the internal flow field, the axial force, the radial force, and the pressure pulsation of the pump were analyzed. Results show that efficiency of the improving scheme 1 under the design flow rate is 77.47%, which can balance 69.82% of the axial force, while efficiency of the improving scheme 2 under the design flow rate is the maximum, which could still balance 62.74% of the axial force. The pressure pulsations of the improving scheme 2 at the typical monitoring points are less than that of the improving scheme 1 and the original scheme. The difference of the radial force peak between the improving scheme 1 and the improving scheme 2 is very small. The vector distributions of the radial force of the improving scheme 1 and the improving scheme 2 are more uniform than that of the original scheme. Considering the efficiency, pressure pulsation, and axial force, experiment measurements on the improving scheme 2 were carried out to verify the effectiveness of the improvement result. Results of energy performance experiment show that efficiency of the improving scheme 2 under the design flow rate is 76.48%, which is 5.26 percentage points higher than that of the original scheme.

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