General model to predict performance degradation in centrifugal pumps.

2021 ◽

Author(s):

Andrew Eaton ◽

Wael Ahmed ◽

Marwan A. Hassan

Keyword(s):

Principal Component Analysis ◽

Distribution Systems ◽

Water Distribution ◽

Principal Component ◽

Component Analysis ◽

Performance Degradation ◽

Centrifugal Pumps ◽

Pump Performance ◽

Hydraulic Machines ◽

Wide Range

Abstract Centrifugal pumps are used in a variety of engineering applications, such as power production, heating, cooling, and water distribution systems. Although centrifugal pumps are considered to be highly reliable hydraulic machines, they are susceptible to a wide range of damage due to several degradation mechanisms, which make them operate away from their best efficiency range. Therefore, evaluating the energy efficiency and performance degradation of pumps is an important consideration to the operation of these systems. In the present study, the hydraulic performance along with the vibration response of an industrial scale centrifugal pump (7.5KW) subjected to different levels of impeller unbalance were experimentally investigated. Extensive testing of pump performance along with vibration measurements were carried. Both time and frequency domain techniques coupled with principal component analysis (PCA) were used in this evaluation. The effect of unbalance on the pump performance was found to be mainly on the shaft power, while no change in the flow rate and the pump head were observed. As the level of unbalance increased, the power required to operate the pump at the designated speed increased by as much as 12%. The PCA found to be a useful tool in comparing the pump vibrations in the field in order to determine the presence of unbalance as well as the degree of damage. The results of this work can be used to evaluate and monitor pump performance under prescribed degradation in order to enhance preventative maintenance programs.

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

La Houille Blanche ◽

10.1051/lhb/2018031 ◽

2018 ◽

pp. 41-48 ◽

Cited By ~ 4

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.

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An Experimental Investigation on the Erosion of a Helico-Axial Pump With Gas Presence

Volume 1: Fluid Applications and Systems; Fluid Measurement and Instrumentation ◽

10.1115/fedsm2020-20481 ◽

2020 ◽

Author(s):

Yi Chen ◽

Abhay Patil ◽

Yiming Chen ◽

Gerald Morrison ◽

Marisela Rojas

Keyword(s):

Volume Fraction ◽

Pressure Rise ◽

Leading Edge ◽

Oil And Gas Industry ◽

Performance Degradation ◽

Oil Field ◽

Tip Clearance ◽

Centrifugal Pumps ◽

Impeller Blade ◽

Axial Pump

Abstract Electrical submersible pump (ESP) technology has been widely applied in the oil and gas industry due to its high productivity. However, erosion always causes the reduction of productivity and sometimes even the failure of an ESP system. This study explores the effect of gas presence on erosion mechanism on an ESP which is composed of 4 stages of Helico-Axial Pump (HAP). A 200-hour erosion test has been performed on this ESP. During the test, the ESP was running at 3600 RPM with a liquid flow rate of 880 GPM, 20% inlet Gas Volume Fraction (GVF), and 0.24% sand concentration by weight. Performance tests were conducted every 50 hours to acquire the performance maps and monitor the performance degradation. Analysis of volume/weight loss and performance degradation is conducted to investigate pump wear. Two types of erosion are found at the impeller: the volume loss found notably at the leading edge is mainly caused by two-body impact erosion, while the tip clearance increment between the impeller housing and impeller blade tip is mainly caused by the three-body abrasive erosion. Unlike most conventional centrifugal pumps, there is no observable wear found at the trailing edge of the impeller. The presence of the gas shows a negative effect on both types of erosion. The consequence of the erosion is the performance degradation, especially at the condition with higher pressure rise. It is suggested to apply this HAP in the oil field with more gas and higher bottom hole pressure.

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Experimental Investigations on the Inner Flow Behavior of Centrifugal Pumps under Inlet Air-Water Two-Phase Conditions

Energies ◽

10.3390/en12224377 ◽

2019 ◽

Vol 12 (22) ◽

pp. 4377 ◽

Cited By ~ 5

Author(s):

Si ◽

Zhang ◽

Bois ◽

Zhang ◽

Cui ◽

...

Keyword(s):

Two Phase Flow ◽

Flow Behavior ◽

Bubbly Flow ◽

Performance Degradation ◽

Phase Flow ◽

Centrifugal Pumps ◽

Two Phase ◽

Impeller Blade ◽

Pump Performance ◽

Starting Point

Centrifugal pumps are widely used and are known to be sensitive to inlet air-water two-phase flow conditions. The pump performance degradation mainly depends on the changes in the two-phase flow behavior inside the pump. In the present paper, experimental overall pump performance tests were performed for two different rotational speeds and several inlet air void fractions (αi) up to pump shut-off condition. Visualizations were also performed on the flow patterns of a whole impeller passage and the volute tongue area to physically understand pump performance degradation. The results showed that liquid flow modification does not follow head modification as described by affinity laws, which are only valid for homogeneous bubbly flow regimes. Three-dimensional effects were more pronounced when inlet void fraction increased up to 3%. Bubbly flow with low mean velocities were observed close to the volute tongue for all αi, and returned back to the impeller blade passages. The starting point of pump break down was related to a strong inward reverse flow that occurred in the vicinity of the shroud gap between the impeller and volute tongue area.

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On the Performance Degradation of Centrifugal Pumps

Proceedings of the 5th International Conference of Fluid Flow, Heat and Mass Transfer (FFHMT'18) ◽

10.11159/ffhmt18.158 ◽

2018 ◽

Author(s):

A. Eaton ◽

F. D’Alessandro ◽

W. Ahmed ◽

H. Hassan

Keyword(s):

Performance Degradation ◽

Centrifugal Pumps

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Numerical Study of the Performance Loss of A Centrifugal Pump Carrying Emulsion

E3S Web of Conferences ◽

10.1051/e3sconf/202132101010 ◽

2021 ◽

Vol 321 ◽

pp. 01010

Author(s):

Lila Achour ◽

Mathieu Specklin ◽

Idir Belaidi ◽

Smaine Kouidri

Keyword(s):

Centrifugal Pump ◽

Numerical Study ◽

Fluid Dynamic ◽

Performance Degradation ◽

Operating Conditions ◽

Centrifugal Pumps ◽

Two Phase ◽

Performance Loss ◽

Cfd Models ◽

Phase Liquid

The performance and hydrodynamic behavior of centrifugal pumps when handling two-phase liquid-liquid flow and emulsion remain relatively unexplored, although they are of fundamental importance in optimizing the operating conditions of these pumps. Hence, this study aims at investigating the performance degradation of a centrifugal pump under emulsion flow by combined means of analytical and computational fluid dynamic (CFD) models. The analytical approach is based on internal energy loss equations while the CFD approach models the emulsion as a continuous and homogeneous single-phase fluid exhibiting shear thinning behavior. The results give a good insight into the performance degradation of such a system, especially at the best efficiency point (BEP).

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