Design Optimization of Splitter Blade Impeller in a Centrifugal Pump

2020 ◽  
Author(s):  
Shunya Takao ◽  
Kentarou Hayashi ◽  
Masahiro Miyabe
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Design Method ◽  
General Purpose ◽  
Stable Operation ◽  
Centrifugal Pumps ◽  
Unstable Flow ◽  
Rate Range ◽  
Flow Rate Range ◽  
Suction Performance

Abstract In order to improve suction performance, centrifugal pumps with an inducer are used for rocket pumps, liquid gas transport such as LNG, and general-purpose pumps. Since a higher suction performance than conventional pump is required, a splitter blade that consists of a long blade and a short blade is sometimes adopted. However, the design becomes more difficult due to the increased number of parameters. The stable operation over a wide flow rate range are required in the general-purpose pumps. Therefore it is necessary to design them so that unstable flow phenomena such as surges do not occur. However, the design method to avoid them is not well understood yet. In this study, we focused on the splitter blade impeller in a general-purpose low-speed centrifugal pump with an inducer. Six parameters such as leading edge position and trailing edge position of the short blade for both hub-side and tip-side were set as design ones. A multi-objective optimization method using a commercial software was applied to improve suction performance while maintaining high efficiency. Then obtained optimal shape were analyzed by CFD calculation and extracted the feature. Furthermore, optimized impellers were manufactured and confirmed the performance over a wide flow rate range by experiments. In addition, a optimizing design method that improves pump performance at lower cost was studied.

Measurements of Axial and Radial Thrust Forces Working on a Three-Stages Centrifugal Pump Rotor

2015 ◽  
Author(s):  
Tetsuya Yamashita ◽  
Satoshi Watanabe ◽  
Yoshinori Hara ◽  
Hiroyoshi Watanabe ◽  
Kazuyoshi Miyagawa
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Axial Direction ◽  
Low Flow ◽  
Axial Thrust ◽  
Rate Range ◽  
Wide Range ◽  
Flow Rate Range ◽  
Three Stages ◽  
Thrust Forces

In this study, radial and axial thrust forces working on the whole rotor in a three-stages centrifugal pump are measured in a wide range of flow rate. The forces are measured at two floating journal bearings and one floating ball bearing, which are supported by the individual load cells. The effects of the offset of rotor position in the axial direction on the thrust forces are investigated. It is found that the effect of the axial offset is significant for the axial thrust force in the low flow rate range, whereas it has little influence on the head and efficiency performances in the whole flow rate range.

Effect of Pre-Whirl on Unstable Flow Suppression in a Centrifugal Impeller With Ring Groove Arrangement

2006 ◽  
Author(s):  
Masahiro Ishida ◽  
Daisaku Sakaguchi ◽  
Hironobu Ueki
Keyword(s):  
Flow Rate ◽  
Guide Vane ◽  
Pressure Rise ◽  
Centrifugal Impeller ◽  
Unstable Flow ◽  
Ring Groove ◽  
Rate Range ◽  
Recirculation Flow ◽  
Setting Angle ◽  
Flow Rate Range

In order to obtain a wider operating range in a centrifugal impeller with inducer, the effect of the pre-whirl induced by the inlet recirculation flow on the flow incidence and the impeller characteristics were analyzed numerically and compared with the experimental results. In order to control the swirl intensity of the recirculation flow, guide vanes were installed circumferentially in the annular bypass of the ring groove arrangement, and the setting angle of the guide vane was changed. The fundamental concept for surge suppression is to achieve the flow incidence less than or close to the critical one. A too large-positive flow incidence can be reduced by increasing the recirculation flow rate determined by the pressure difference between the two ring groove positions, on the other hand, a higher pressure rise in the inducer can be obtained at the flow incidence close to the critical one by suppressing the pre-whirl induced by the recirculation flow. It is clearly shown that the better impeller characteristics and the large recirculation flow rate can be achieved by giving a suitable setting angle of the guide vane. The unstable flow rate range of the tested impeller was reduced by about 53% almost without deterioration of the impeller efficiency in the whole flow rate range.

Experimental Investigation of Pressure Fluctuations on Inner Wall of a Centrifugal Pump

2019 ◽  
Vol 36 (4) ◽  
pp. 401-410 ◽  
Author(s):  
Xiao-Qi Jia ◽  
Bao-Ling Cui ◽  
Zu-Chao Zhu ◽  
Yu-Liang Zhang
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Pressure Fluctuation ◽  
Pressure Fluctuations ◽  
High Flow ◽  
Low Flow ◽  
Centrifugal Pumps ◽  
Flow Rates ◽  
Pressure Distributions ◽  
Blade Passing Frequency

Abstract Affected by rotor–stator interaction and unstable inner flow, asymmetric pressure distributions and pressure fluctuations cannot be avoided in centrifugal pumps. To study the pressure distributions on volute and front casing walls, dynamic pressure tests are carried out on a centrifugal pump. Frequency spectrum analysis of pressure fluctuation is presented based on Fast Fourier transform and steady pressure distribution is obtained based on time-average method. The results show that amplitudes of pressure fluctuation and blade-passing frequency are sensitive to the flow rate. At low flow rates, high-pressure region and large pressure gradients near the volute tongue are observed, and the main factors contributing to the pressure fluctuation are fluctuations in blade-passing frequency and high-frequency fluctuations. By contrast, at high flow rates, fluctuations of rotating-frequency and low frequencies are the main contributors to pressure fluctuation. Moreover, at low flow rates, pressure near volute tongue increases rapidly at first and thereafter increases slowly, whereas at high flow rates, pressure decreases sharply. Asymmetries are observed in the pressure distributions on both volute and front casing walls. With increasing of flow rate, both asymmetries in the pressure distributions and magnitude of the pressure decrease.

Improving the Hall Thruster Global Efficiency over a Wide Flow-Rate Range

2021 ◽  
pp. 1-9
Author(s):  
Hao-tian Fan ◽  
Hong Li ◽  
Wei Mao ◽  
Yong-Jie Ding ◽  
Li-Qiu Wei ◽  
...  
Keyword(s):  
Flow Rate ◽  
Hall Thruster ◽  
Rate Range ◽  
Global Efficiency ◽  
Flow Rate Range

Clocking effect in a centrifugal pump with a vaned diffuser

2020 ◽  
Vol 34 (26) ◽  
pp. 2050286
Author(s):  
Fen Lai ◽  
Xiangyuan Zhu ◽  
Yongqiang Duan ◽  
Guojun Li
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Pressure Loss ◽  
Total Pressure ◽  
Radial Force ◽  
Design Flow ◽  
Total Pressure Loss ◽  
Inlet Section ◽  
Centrifugal Pumps ◽  
Installation Angle

The performance and service life of centrifugal pumps can be influenced by the clocking effect. In this study, 3D numerical calculations based on the k-omega shear stress transport model are conducted to investigate the clocking effect in a centrifugal pump. Time-averaged behavior and transient behavior are analyzed. Results show that the optimum diffuser installation angle in the centrifugal pump is [Formula: see text] due to the minimum total pressure loss and radial force acting on the impeller. Total pressure loss, particularly in the volute, is considerably influenced by the clocking effect. The difference in total pressure loss in the volute at different clocking positions is 2.75 m under the design flow rate. The large total pressure loss in the volute is primarily caused by the large total pressure gradient within the vicinity of the volute tongue. The radial force acting on the impeller is also considerably affected by the clocking effect. When the diffuser installation angle is [Formula: see text], flow rate fluctuations in the volute and impeller passage are minimal, and flow rate distribution in the diffuser passage is more uniform than those in other diffuser installation angles. Moreover, static pressure fluctuations in the impeller midsection and the diffuser inlet section are at the minimum value. These phenomena explain the minimum radial force acting on the impeller. The findings of this study can provide a useful reference for the design of centrifugal pumps.

Comparison of Inlet Curved Disk Arrangements for Suppression of Recirculation in Centrifugal Pump Impellers

2016 ◽  
Author(s):  
Munther Y. Hermez ◽  
Badih A. Jawad ◽  
Liping Liu ◽  
Vernon Fernandez ◽  
Kingman Yee ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
High Speed ◽  
Operating Cost ◽  
Three Dimensional ◽  
Centrifugal Pumps ◽  
Unstable Flow ◽  
Pump Impeller ◽  
Flow Rates ◽  
Flow Recirculation ◽  
Flow Field Characteristics

The present work aims to numerically study the inlet flow recirculation and modified impeller interaction in a centrifugal pump. An optimization of modified shrouded impeller with curved disk arrangement to suppress the unsteady flow recirculation is pursued. This modification will enhance the impeller characteristics with a wider operation range at both low and high flow rates in a high speed centrifugal pump type. The unstable flow in the centrifugal pumps is a common problem that leads to damage in the pump’s internal parts, consequently increases the operating cost. At certain flow rates, generally below the Best Efficiency Point (BEP), all centrifugal pumps are subject to internal recirculation occurs at the suction and discharge areas of the impeller. For decades, experimental work has been done to investigate the complex three-dimensional flow within centrifugal pumps impellers, before computational work gains momentum due to advancement of computing power and improved numerical codes. In this study the impeller with a curved disk arrangement has been investigated by using a three-dimensional Navier-Stokes code with a standard k-ε turbulence model. The purpose is to evaluate and select the optimum impeller modification that would increase the pump suction flow rate range. Three-dimensional numerical Computational Fluid Dynamics (CFD) tools are used to simulate flow field characteristics inside the centrifugal pump and provide critical hydraulic design information. In the present work, ANSYS v.16.1 Fluent solver is used to analyze the pressure and velocity distributions inside impeller suction and discharge passages. The ultimate goal of this study is to manufacture and validate the most optimized and efficient centrifugal pump impeller with a curved disk. The best case curve identifies the highest increase of total pressure difference by 22.1%, and highest efficiency by 92.3% at low flowrates.

Research of Wet Gas Experimental Facility with Adjustable and Intermediate Pressure

2012 ◽  
Vol 220-223 ◽  
pp. 875-879
Author(s):  
Ying Xu ◽  
Cun Yin ◽  
Zheng Hai Long
Keyword(s):  
Measurement Uncertainty ◽  
Flow Rate ◽  
Gas Flow ◽  
Uncertainty Assessment ◽  
Experimental Facility ◽  
Rate Range ◽  
Intermediate Pressure ◽  
Loop Design ◽  
Wet Gas ◽  
Flow Rate Range

In order to better simulate the flowing condition of wet gas, Tianjin University has designed and built up a wet gas flow experimental facility with adjustable and intermediate pressure in the flow laboratory. The designed pressure of the facility which used standard meter method and dual closed-loop design is 4MPa. The experiment medium is air and water, and the highest operation pressure is 1.6MPa. The gas flow rate range is 3~1000m3/h, and the liquid flow rate range is 0.05~8 m3/h. This article includes the structure introduction of the facility and the calculation of pressure loss of the system, etc. By the uncertainty assessment for the discussed facility, the conclusion is stated that the facility’s gas measurement uncertainty is 1% and the facility’s liquid measurement uncertainty is 0.35%.

A Survey of Modern Centrifugal Pump Practice for Oilfield and Oil Refinery Services

1943 ◽  
Vol 150 (1) ◽  
pp. 121-134 ◽  
Author(s):  
N. Tetlow
Keyword(s):  
Centrifugal Pump ◽  
Chemical Engineering ◽  
Saturation Pressure ◽  
Difficult Problem ◽  
Future Trend ◽  
Oil Refinery ◽  
Engineering Practice ◽  
Centrifugal Pumps ◽  
Oil Companies ◽  
Suction Performance

During the last thirty years there has been a manifold increase in the demand for centrifugal pumps for oilfield and oil refinery service, an increase in which British engineers have played a worthy part. With traditional British reticence little has been said of the achievements of British oil companies and British pump manufacturers in this field of activity, and the author has written this paper with the object of correcting the omission. In the field of oil transportation over long distances, for instance, the influence of British practice is to be seen in many oilfields throughout the world. Within the refinery considerable strides have been made, particularly in solving the difficult problem of handling unstable hydrocarbon liquids under high suction pressures. Hot oil pump practice is now more or less established, and in this development the greater share of credit is due to American pump manufacturers. These developments are dealt with at some length in the appropriate section of the paper. Another point which calls for comment here is the introduction of a new term, for the characteristic of flow into the impeller eye, which is used in section 3 of the paper. When dealing with hydrocarbon liquids under saturation pressure and temperature conditions, the so-called “suction performance” of a centrifugal pump becomes extremely important. As a description of this most important characteristic of a pump the use of the phrase “suction performance” is misleading, and it has led to much confusion of thought. An attempt has been made to reduce the possibility of further confusion by coining a new phrase based on the analogy of similar characteristics encountered in electrical engineering. Throughout the paper, therefore, the pump characteristic relating to flow into the impeller eye has been described as the characteristic of “flow inductance”. The paper would not be complete without an attempt to assess the future trend. There will probably be a much greater tendency towards electrification of main-line pumping plant. A further increase in operating temperatures and pressures will, no doubt, lead to many fundamental changes in the design of pumping plant for use inside the refinery. As an example, it is suggested that for some difficult duties it may be necessary to adopt pump designs in which stuffing boxes are avoided altogether. Finally, it is probable that refinery technologists will tend more and more to adopt chemical processes and chemical engineering practice, so introducing new problems for the pump designer.

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