Health Monitoring of Centrifugal Pumps Using Digital Models

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Amr A. Abdel Fatah ◽  
Mohammed A. Hassan ◽  
Mohamed Lotfy ◽  
Antoine S. Dimitri
Keyword(s):  
Centrifugal Pump ◽  
Fluid Dynamic ◽  
Rapid Development ◽  
Dynamic Performance ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Normal Operation ◽  
Centrifugal Pumps ◽  
Digital Models ◽  
Exciting Forces

The area of predictive maintenance (PM) has received growing research interest in the past few years. Diagnostic capabilities of PM technologies have increased due to advances made in sensor technologies, signal processing algorithms, and the rapid development of computational power and data handling algorithms. Conventional PM programs are mostly built around analyzing sensors' data collected from physical systems. Incorporating simulation data collected from digital models replicating the physical system with sensors' data can lead to more optimization for operation and maintenance. This paper demonstrates the role of using digital models in implementing effective condition monitoring on centrifugal pumps. Two digital models are used to study the dynamic performance of a centrifugal pump experiencing cavitation condition. The first model is a three-dimensional fully turbulent computational fluid dynamic (CFD) model. Based on the pressure distribution obtained from the CFD, a novel analytical pressure pulsation model is developed and used to simulate the exciting forces affecting the pump. The second digital model is a pump casing dynamic model which is used to predict the casing vibration response to exciting forces due to faulty operating conditions. Results obtained from the digital models are validated using an experimental test rig of a small centrifugal pump. Using this concept, a pump faulty operation can be simulated to provide complete understanding of the root cause of the fault. Additionally, digital models can be used to simulate different corrective actions that would restore the normal operation of the pump.

Research on Improving the Dynamic Performance of Centrifugal Pumps With Twisted Gap Drainage Blades

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Zheng-Chuan Zhang ◽  
Hong-Xun Chen ◽  
Zheng Ma ◽  
Jian-Wu He ◽  
Hui Liu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Pump ◽  
Dynamic Characteristics ◽  
Dynamic Performance ◽  
Three Dimensional ◽  
Hydraulic Performance ◽  
Operating Conditions ◽  
Navier Stokes ◽  
Centrifugal Pumps ◽  
Practical Applications

Through numerical simulation and experiments analysis, it is indicated that the hydraulic and anticavitation performance of a centrifugal pump with twisted gap drainage blades based on flow control theory can be significantly improved under certain operating conditions. In order to introduce the technology of gap drainage to practical applications, we put forward the parameter formulas of the twisted gap drainage blade to design three-dimensional new type blade, which are also proved to be effective for enhancing the dynamic characteristics of the centrifugal pump. Furthermore, a practical centrifugal pump is redesigned to be a twisted gap drainage impeller with the same structure size as the original impeller, and the nonlinear hybrid Reynolds-averaged Navier–Stokes (RANS)/large eddy simulation (LES) method is employed to simulate the hydraulic dynamic characteristics. Numerical simulation results show that the hydraulic performance and dynamic characteristics of the redesigned impeller centrifugal pump are significantly enhanced. In experiments, the twisted gap drainage blades structure not only remarkably improves the hydraulic performance and the pressure pulsation characteristics of the centrifugal pump but also reduces the vibration intensity.

Optimization of Curved Spacer Prototype Design for Flow Improvement in Centrifugal Pump Impeller

2018 ◽  
Author(s):  
Munther Y. Hermez ◽  
Badih Jawad ◽  
Liping Liu ◽  
Sabah Abro
Keyword(s):  
Flow Field ◽  
Centrifugal Pump ◽  
Water Flow ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Stable Operation ◽  
Inlet Section ◽  
Computational Domain ◽  
Centrifugal Pumps ◽  
Flow Recirculation

An optimization of modified shrouded impeller with a curved spacer to suppress the unsteady flow recirculation was pursed. Centrifugal pumps are required to sustain a stable operation of the system they support under all operating conditions. Effect of minor geometrical modifications on the flow inside the three dimensional impeller passages are yet not fully understood, leading to costly trial and error approaches in the solution of instability problems. The idea of using a curved spacer to enhance the specified centrifugal impeller characteristics was validated. This modification with positioning the successful curved spacer prototype model at the impeller inlet section provided a wider pressure operation range at both low and high flow rates in a high-speed centrifugal pump type. Seven curved spacer models were numerically analyzed in combination with the same original closed type impeller. The research investigated the effects of each inlet curved spacer model on the impeller’s performance improvement. The flow field inside a centrifugal pump is known to be fully turbulent, three-dimensional, and unsteady associated with secondary flow recirculation and separation at the impeller’s inlet and exit section. The rotor-stator interaction mechanisms or other unsteady effects often influence the water flow. The present research addresses the problem of Net Positive Suction Head Required (NPSHR) increase due to flow recirculation at the impeller suction side. The three dimensional unsteady water flow inside different models were analyzed by using a 3-D Navier-Stokes code with a standard k-ε turbulence model. The computational domain consists of four main zones: inlet, impeller hub, vanes, and outlet. The measurements with test rig were conducted for the pump hydraulic performances and flow field in the impeller passages. The numerical simulation and experimental tests of prototype performance concluded: (1) Positioning a 3-D curved spacer at the impeller inlet section has a great impact on the centrifugal pump performance. (2) Favorite effects were achieved on impeller performance by separating the inlet flow region into two lanes. (3) The curved spacer resulted in improvement of closed impeller inlet static and total pressure values. (4) Q-ΔP-η data and flow structures in the impeller passages were analyzed.

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

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).

Experimental and Numerical Investigation of Centrifugal Pump Performance When Handling Viscous Fluids

2005 ◽  
Author(s):  
M. H. Shojaee Fard ◽  
M. B. Ehghaghi ◽  
F. A. Boyaghchi
Keyword(s):  
Soviet Union ◽  
Centrifugal Pump ◽  
Turbulent Flows ◽  
Characteristic Curve ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Viscous Fluids ◽  
Test Bed ◽  
Flow Process ◽  
Pump Performance

On the test bed of centrifugal pump, the centrifugal pump performance has been investigated using water and viscous oil as Newtonian fluids, whose kinematic viscosities are 1 × 10−6, 43 × 10−6 and 62 × 10−6 m2/s, respectively. Also, the finite volume method is used to model the three dimensional viscous fluids for different operating conditions. For these numerical simulations the SIMPLEC algorithm is used for solving governing equations of incompressible viscous/turbulent flows through the pump. The κ-ε turbulence model is adopted to describe the turbulent flow process. These simulations have been made with a steady calculation and using the multiple reference frame (MRF) technique to take into account the impeller-volute interaction. Numerical results are compared with the experimental characteristic curve for each viscous fluid. The data obtained allow the analysis of the main phenomena existent in this pump, such as: head, efficiency, power and pressure field changes for different operating conditions. Also, the correction factors for oils are obtained from the experimental for part loading (PL), best efficiency point (BEP) and over loading (OL) and the results are compared with proposed factors by American Hydraulic Institute (HIS) and Soviet Union (USSR). The comparisons between the numerical and experimental results show a good agreement.

Centrifugal Pump Leak-Free Technology Introduction and Its Applications in EPR Nuclear Power Plant

2010 ◽  
Author(s):  
Guohui Cong ◽  
Ling Zhang
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Centrifugal Pump ◽  
Nuclear Power ◽  
Operating Conditions ◽  
Critical Conditions ◽  
Mechanical Seal ◽  
Centrifugal Pumps ◽  
Canned Motor ◽  
Magnetic Drive

Environmental protection requirement is more and more critical now, and it increases the request to prevent dangerous liquid to leak outside in nuclear power plant too. Centrifugal pumps are the most important active equipments in nuclear power plant, but there is a shaft clearance between rotor and stator of centrifugal pump. The shaft clearance can lead pumped fluid to the outside, so the environment may be polluted by the leakage. In some critical conditions such as transferring high radioactive fluid in the pump, the leakage shall be totally forbidden. So solutions have to be found to make centrifugal pumps totally leak-free for applications in nuclear power plant. Normally there are three leak-free technologies for centrifugal pumps: mechanical seal with auxiliary system, canned motor and magnetic drive. In this paper, all the three leak-free technologies and some of their applications in EPR 3rd generation PWR nuclear power plants are presented and discussed. The results show that in EPR nuclear power plant, canned motor pumps can be preferably used for strict environmental requirement of leak-free if the pump power and operating conditions are applicable. For other conditions, pumps with double mechanical seal can also be used with additional sealing water system support. For centrifugal pumps with magnetic drive are not so applicable in high pressure condition, and the safety aspect is weaker than canned motor pumps, generally they are not used in EPR nuclear power plant at present.

Optimal Design and Experimental Study on 500SM35 Type Centrifugal Pump

2010 ◽  
Vol 29-32 ◽  
pp. 1003-1007
Author(s):  
Ming Wei Hou
Keyword(s):  
Centrifugal Pump ◽  
Optimization Design ◽  
High Efficiency ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Multi Objective Optimization ◽  
Centrifugal Pumps ◽  
Design Specification ◽  
Turbulence Flow ◽  
Hydraulic Design

To make the high efficiency and energy-saving centrifugal pump, using multi-objective optimization design to make hydraulic design of the 500SM35 centrifugal pumps, using CFD technology to simulate the three-dimensional turbulence flow in pump, also make performance experiment and cavitation experiment of the 500SM35 centrifugal pump that have been self-developed. Experimental studies have shown that: the 500SM35 centrifugal pump’s prototype performance parameters all beyond design specification.

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.

The effect of wear ring clearance on flow field in the impeller sidewall gap and efficiency of a low specific speed centrifugal pump

2017 ◽  
Vol 232 (17) ◽  
pp. 3062-3073 ◽  
Author(s):  
M DaqiqShirazi ◽  
R Torabi ◽  
A Riasi ◽  
SA Nourbakhsh
Keyword(s):  
Flow Field ◽  
Centrifugal Pump ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Volumetric Efficiency ◽  
Centrifugal Pumps ◽  
Disk Friction ◽  
Low Specific Speed ◽  
Overall Efficiency ◽  
Specific Speed

In this paper, the flow in the impeller sidewall gap of a low specific speed centrifugal pump is analyzed to study the effect of wear ring clearance and the resultant through-flow on flow field in this cavity and investigate the overall efficiency of the pump. Centrifugal pumps are commonly subject to a reduction in the flow rate and volumetric efficiency due to abrasive liquids or working conditions, since the wear rings are progressively worn, the internal leakage flow is increased. In the new operating point, the overall efficiency of the pump cannot be predicted simply by using the pump characteristic curves. The flow field is simulated with the use of computational fluid dynamics and the three-dimensional full Navier–Stokes equations are solved using CFX software. In order to verify the numerical simulations, static pressure field in volute casing and pump performance curves are compared with the experimental measurements. The results show that, for the pump with minimum wear ring clearance, the disk friction efficiency is the strongest factor that impairs the overall efficiency. Therefore, when the ring clearance is enlarged more than three times, although volumetric efficiency decreases effectively but the reduction in overall efficiency is remarkably smaller due to improvement in the disk friction losses.

Experimental and Numerical Study of Stall Flutter in a Transonic Low-Aspect Ratio Fan Blisk

2003 ◽  
Author(s):  
A. J. Sanders ◽  
K. K. Hassan ◽  
D. C. Rabe
Keyword(s):  
Aspect Ratio ◽  
Numerical Study ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Tip Clearance ◽  
Strain Gages ◽  
Pressure Transducers ◽  
Low Aspect Ratio ◽  
Benchmark Data

Experiments are performed on a modern design transonic shroudless low-aspect ratio fan blisk that experienced both subsonic/transonic and supersonic stall-side flutter. High-response flush mounted miniature pressure transducers are utilized to measure the unsteady aerodynamic loading distribution in the tip region of the fan for both flutter regimes, with strain gages utilized to measure the vibratory response at incipient and deep flutter operating conditions. Numerical simulations are performed and compared with the benchmark data using an unsteady three-dimensional nonlinear viscous computational fluid dynamic (CFD) analysis, with the effects of tip clearance, vibration amplitude, and the number of time steps-per-cycle investigated. The benchmark data are used to guide the validation of the code and establish best practices that ensure accurate flutter predictions.

Solution of Cavitation Problems in Pumps by Means of Model Air Testing

1965 ◽  
Vol 2 (04) ◽  
pp. 422-430
Author(s):  
K. Pilarczyk ◽  
Vasil Rusak
Keyword(s):  
Centrifugal Pump ◽  
Radial Direction ◽  
Three Dimensional ◽  
Flow Distribution ◽  
Operating Conditions ◽  
Original Design ◽  
Velocity Pattern ◽  
Standard Values ◽  
Suction Nozzle ◽  
Dimensional Picture

This paper describes a case of rather unusual and severe cavitation in a double-suction centrifugal pump and the way the problem was corrected. The cavitation was demonstrated in a heavy erosion in the impeller blades while the performance of the pump did not show any signs of deterioration. The original design of the pump and the operating conditions were rather conventional with the available NPSH exceeding the recommended Hydraulic Institute Standard values. To solve this problem it was necessary to study, in detail, the velocity pattern at the impeller inlet. For this purpose, a wooden model of the pump suction nozzle was built and tested with air. A three-dimensional picture of the flow distribution in the impeller eye was obtained from this test indicating a considerable nonunlformlty in both the circumferential and the radial direction. This information led to the redesign of the impeller-inlet passage which ultimately eliminated the cavitation.

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