Pump Vibration Research Articles

Influence of shaft combined misalignment on vibration and noise characteristics in a marine centrifugal pump

Shaft combined misalignment is the main form of shaft misalignment fault in a marine centrifugal pump. To investigate the influence of shaft misalignment on the vibration and noise of marine centrifugal pumps, a marine pump is experimentally measured under normal condition and shaft combined misalignment condition. In this paper, the frequency domain characteristics of vibration and noise are analyzed by Fast Fourier transform technique. The characteristics of axis orbit, the spectral characteristics of vibration and noise, and the One-Third octave spectral distribution characteristics are also comprehensively compared. Results show that after shaft combined misalignment occurs, the maximum amplitudes of 1APF (axial passing frequency) in the X and Y directions at M1 increase by 35.06% and 24.04%, the maximum amplitudes of 2APF in the X and Y directions at M1 increase by 2.61 times and 2.61 times, and the axis orbit shows a clockwise variation of the “8” shape. As the flow rate decreases, the shape of an “8” of the rotor axis orbit becomes progressively flatter. The maximum Overall vibration velocity level (OAVL) of M2 and M5 decreases by 12.03% and 1.79%, and the maximum OAVL of M3 and M4 increases by 6.52% and 2.27%. The frequency domain amplitude of M6 increases significantly in 1APF and 2APF, and the maximum increases are 12.41% and 2.24% at different flow rates. The overall sound pressure level of M6 increases by 0.42% at 0.6 Qd. These findings indicate the vibration energy of M1-M5 and noise energy of M6 are related to the running condition. The axis orbit of M1 shows the shape of 8, which can significantly judge the misalignment of the shafting. Then, combined with the amplitude variation of 1APF and 2APF of the M2-M6 spectrum, the comprehensive misalignment of shafting can be further judged. The above discoveries provide reference to the diagnosis of shaft combined misalignment fault that occurred for the marine pump.

Control and Dynamic Characteristics Analysis for the Double-Compound Axial Piston Pump Based on Working Conditions

The periodic flow and pressure pulsation of the axial piston pump can lead to periodic vibration, noise, and even damage to various components in the hydraulic system. Therefore, the dynamic characteristics analysis of the axial piston pump in the hydraulic system is of great significance for reducing vibration and noise in the hydraulic system and improving efficiency. The double-compound axial piston pump is the key component of a high power and large flow hydraulic power system, which has a special power control mode. In this paper, the working and control principles of the double-compound axial piston pump are analyzed, the numerical model of the double-compound axial piston pump is established, and the effectiveness of the model is verified through experimental tests. The constant power control characteristics of the double-compound axial piston pump under different power settings and the variable power control characteristics under the rated load pressure are analyzed. By analyzing the dynamic characteristics of the double-compound axial piston pump, the influence of different working conditions on the dynamic characteristics is investigated. The results show that the output efficiency of the double-compound axial piston pump is higher when the output flow is larger. When the piston chamber works in the closed pre-compression pressure zone and the closed pre-release pressure zone, oil backflow occurs. The oil backflow in the piston chamber seriously intensifies the outlet flow pulsation of the double-compound axial piston pump. The flow pulsation rate is positively correlated with load pressure and power control pilot pressure, while negatively correlated with spindle speed. The paper provides a basis for the analysis and optimization of power control, flow pulsation, fluid vibration, and noise of the double-compound axial piston pump.

Research Status and Prospect for Vibration, Noise and Temperature Rise-Based Effect of Food Transport Pumps on the Characteristics of Liquid Foods.

In the field of food processing, the processing of liquid foods has always played an important role. Liquid foods have high requirements for the processing environment and equipment. As the core equipment in liquid foods processing, food transport pumps are widely used in liquid foods production, processing and transportation. Most liquid foods are non-Newtonian and vulnerable to vibration, noise, and temperature rise produced by rotary motions of food transport pumps in operation, which can finally affect foods safety. Therefore, this review summarizes the impact of mechanical vibration, noise, and temperature rise on liquid food products, with the aim of ensuring food safety while designing a cleaner, safer and more reliable food transport pumps in the future.

Cavity molecular dynamics of vibrational modes enhanced non-linear absorption and population dynamics

We present a quantum description of SERRS, in analogy to the energy spectrum dynamics for a system that comprises two molecules interacting with a single plasmonic cavity, taking into account the effect of molecular vibrations and Van der Waals interactions between the two molecules. It is shown that the splitting of the transparency peak can easily distinguish two adjacent molecules with similar chemical structures and nearly equal vibrational frequencies. We also found that vibrational pumping can selectively activate a particular vibrational mode, thus providing a mechanism to control its population dynamics and drives plasmon-assisted chemistry. Our results will provide a new approach for understanding the role of cavity photons in a two-level system comprising interacting polaritons and phonons.

Analysis and Solutions of Boiler Feed Water Pump Vibration in Thermal Power Plant

Analysis and Solutions of Boiler Feed Water Pump Vibration in Thermal Power Plant

Hydrodynamic Performance and Vibration and Noise of Machine-pump Integration Device

As a new type of drainage equipment or underwater propeller, the machine pump integrated device composed of permanent magnet motor and pump blade of Halbach structure has many advantages and wide application prospects. Starting from the hydrodynamic analysis method of the machine pump integrated device, this paper reviews the research progress in this field at home and abroad in recent years. The results are summarized and analyzed. Finally, according to the current problem needs and the shortcomings of the research status, some ideas are put forward for the vibration and noise suppression method of the machine pump integrated device, which provides a reference for the follow-up related research.

Research of the Flow Attenuation Mechanism of a Double-Suction Pump

As an important machine for energy conversion and fluid transmission, centrifugal pump has the advantages of high efficiency, reliable performance, and easy adjustment. In order to improve the stability of the pump, this article adopts the method of experimental and numerical simulation in the pump and studies the variation of the vibration characteristics in the operation process. Based on the numerical simulation results, the intake condition and the cavitation inside the centrifugal pump are analyzed and summarized, which reveals the flow attenuation mechanism of a pumping station. The main results of the work reported in this article are as follows: 1) Various experimental schemes to monitor the vibration of centrifugal pumps in real time have been designed. The vibration characteristics of the pumps have been significantly improved by adding special trash barriers. 2) The gas entering the pump was not enough to affect the normal operation of the pump, but cavitation did occur in the actual operation process. 3) The critical net positive suction head under the three conditions is calculated to be 8.9, 10.9, and 12.9 m, respectively.

Effect of Incident Angle of Wear-Ring Clearance on Pressure Pulsation and Vibration Performance of Centrifugal Pump

A wear-ring is an important part of the centrifugal pump. The leakage flow in the wear-ring clearance and main flow at the impeller inlet form crossed mixed flows perpendicular to each other. Large eddies and shocks are produced at the intersection of the two flows due to great velocity difference and different directions, resulting in flow losses, unsteady flow, and even flow-induced vibration. Consequently, the pump performance, pressure pulsation and vibration, and other characteristics will be greatly affected. In this paper, 5 incident angles between the incident section of the wear-ring clearance and the circumferential direction of impeller inlet, i.e., the original angle (90°), 75°, 60°, 45°, and 30°, were formed with a low-specific-speed centrifugal pump as the study object. Unsteady flow calculation and fluid–structure interaction calculation were performed on centrifugal pumps with different wear-ring clearances; the effect of the incident angle of the wear-ring clearance on the distribution of pressure pulsation and vibration performance of centrifugal pump was analyzed. The results showed that the improved efflux angle of the wear-ring clearance could effectively weaken the impact disturbance of the leakage flow in the wear-ring clearance to the main flow at the inlet. Accordingly, the flow status at the inlet of the centrifugal pump was improved, flow losses were reduced, the efficiency of the centrifugal pump was improved, and the vibration amplitude and vibration energy of the pump were also reduced.

N2 vibrational excitation in atmospheric pressure ns pulse and RF plasma jets

Time-resolved N2 vibrational temperature and translational–rotational temperature in quasi-two-dimensional atmospheric pressure plasma jets sustained by ns pulse and RF discharges in nitrogen/noble gas mixtures are measured by the broadband vibrational Coherent Anti-Stokes Raman Scattering (CARS) . The results indicate a much stronger vibrational excitation in the RF plasma jet, due to the lower reduced electric field and higher discharge power. In a ns pulse discharge in N2/He, N2 vibrational temperature is significantly lower compared to that in N2/Ar, due to the more rapid vibration–translation (V–T) relaxation of nitrogen by helium atoms. In the RF plasma jets in N2/Ne and N2/Ar, the vibrational excitation increases considerably as the nitrogen fraction in the mixture is reduced. The experimental data in the RF plasma jet in N2/Ar jet are compared with the kinetic modeling predictions. The results indicate that nitrogen vibrational excitation in N2/Ar plasma jets with a small N2 fraction in the mixture (several percent) is controlled primarily by electron impact, anharmonic vibration–vibration (V–V) pumping, and V–T relaxation by N atoms. In comparison, V–V energy transfer from the vibrationally excited molecules in the first excited electronic state, N2(A3Σu +, v), which are generated primarily by the energy transfer from the metastable Ar atoms, has a minor effect on the vibrational populations of the ground electronic state, N2(X1Σg +, v). Although the discharge energy fraction going to electronic excitation is significant, the predicted quasi-steady-state N2(A3Σu +) number density, controlled by the energy pooling and quenching by N atoms, remains relatively low. Because of this, the net rate of N2(X1Σg +) vibrational excitation by the V–V energy transfer from N2(A3Σu +) is much lower compared to that by the direct electron impact. The results show that atmospheric pressure RF plasma jets can be used as sources of highly vibrationally excited N2 molecules and N atoms.

Flow Deflection between Guide Vanes in a Pump Turbine Operating in Pump Mode with a Slight Opening

During the startup and shutdown processes of a reversible-pump turbine (RPT) working in pump mode, abnormal sounds and vibrations usually occur in the distributor when the guide vanes (GVs) are at a slight opening (max opening of about 6%). The objective of this paper is to apply a three-dimensional numerical CFD method to study the unsteady flow behavior in the guide vane region of a pump turbine operating in pump mode. The dynamic meshing technique is introduced to simulate the startup and shutdown processes, and it is shown to be critical in accurately capturing the details of the flow pattern variations. In addition, the RNG k-epsilon two-equation turbulence model is applied and the governing equations are discretized with the finite volume method. Moreover, the boundary conditions are set through the calculation of the transient process of the power station. The results show that the main flow between the GVs is deflected during the startup and shutdown processes. In the shutdown process, the deflection occurs when the guide vane opening (GVO) is between 1.99 and 5.32 degrees, on average. In the startup process, the deflection occurs when the GVO is between 2.83 and 4.11 degrees, on average. In these processes, the velocity field and pressure field change dramatically. Simultaneously, the hydraulic torque (HT) on the GVs has a sharp change. The abrupt change in the HT leads to vibrations and abnormal sounds.

Investigation on vibration of Centrifugal Pump by Bearing supported position

Vibration is one of the main problems which should be considered seriously in designing and operating a marine centrifugal pump to decrease vibration for the reliability of equipment and safety of ship. The reduction for vibration also can provide a guarantee for enhancing concealment, which will be benefit for military ships with higher requirements for concealment to improve combat effectiveness. A numerical calculation model of whole centrifugal pump was established in this paper. The emphasis of this article is that influence of bearing supported position on vibration of centrifugal pump. And conclusion was obtained that vibration peak can be reduced through adjust supported position of bearing reasonably. The simulation results was proved by experiment which was carried out in the Shaking Table Test.

Industrial Internet of Things for Condition Monitoring and Diagnosis of Dry Vacuum Pumps in Atomic Layer Deposition Equipment

In the modern semiconductor industry, defective products occur with unexpected small variables due to process miniaturization. Managing the condition of each part is an effective way of preventing unexpected errors. The industrial internet of things (IIoT) environment, which can monitor and analyze the performance degradation of parts that affect process results, enables advanced process yield management. This paper introduces the IIoT concept-based data monitoring and diagnostic system construction results. The process of pump vibration data acquisition is explained to evaluate the effectiveness of this system. The target process is deposition. The purpose of the system is to detect degradation of pumps due to by-products of the atomic layer deposition (ALD) process. The system consists of three areas: a data acquisition unit using six vibration sensors, a Web access-based monitoring unit that can monitor vibration data, and an Azure platform that searches for outliers in vibration data.

A Predict Method of Water Pump Operating State Based on Improved Particle Swarm Optimization of Support Vector Machine

In order to improve prediction accuracy of water pump operating state, a chaotic prediction model of the pump vibration data based on improved particle swarm optimization of support vector machine is proposed in this paper. Firstly, a grouping optimization strategy particle swarm algorithm based on cosine function is proposed. Then, the training set is obtained on the time series of vibration data by phase space reconstruction. Secondly, The improved particle algorithm is used to optimize the penalty parameters, insensitive loss coefficient and width parameters of support vector machine. Then, a prediction model of vibration data is established by using support vector machine combined with training set and optimal parameters. Finally, the operating state of the pump is predicted according to pump vibration measurement and evaluation method. Compared with the method of linear decreasing weight strategy, the method proposed in this paper is more accurately.

Numerical and experimental study in pressure pulsation and vibration of a two-stage centrifugal pump under cavitating condition

Instantaneous cavitating turbulent flow in a two-stage centrifugal pump with diffuser was simulated using a hybrid RANS/LES model and rotating corrected-based cavitation model in this paper. The predicted results of numerical simulation were in good agreement with the experimental results. The mechanism of pressure pulsation in the two-stage centrifugal pump was discussed. Some representative main frequencies of pressure pulsation such as main blade passing frequency, sub-blade passing frequency and intersection frequency of impeller blade and diffuser blade were analyzed systematically. Uncertainty estimation was used to ensure the accuracy of experimental results and it was also used to analyze the variation of pressure pulsation and vibration signals at different positions with the intensification of cavitation degree in the centrifugal pump. According to the results of uncertainty estimation, the center frequency of 1/3 octave band and the root mean square method were used to evaluate the energy change of the pressure pulsation signals and vibration signals at different frequency bands as the cavitation number decreases. The characteristics of pressure pulsation and vibration signals at different positions were analyzed in different frequency bands.

Analisa Kapasitas Struktur Intake Rumah Pompa Karang Anyar, Pulokerto

Intake Building Structure is a Pier Type Structure that is used as a building for the distribution of clean water. This structure stands on a stake that stands on the edge of the river, as a pier-type building that accepts the load of river currents and pump vibration loads, it is necessary to analyze the maximum capacity, economical and also sturdy. There are several important aspects that must be reviewed to get the maximum design, including water current load, soil load, pump vibration load and also earthquake load in the form of spketrum response based on Palembang area. The design reference used is SNI1727-2013 and SNI 1726-2002. Based on the analysis, the intake structure was obtained in the form of reinforced concrete structures on the floor area and pilecap while for the foundation of the stake in the form of composite steel, columns and beams because it supports a heavy enough load, the profile steel is used.

Evaluating the Performance Degradation of Centrifugal Pumps Using the Principal Component Analysis

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 this study, the hydraulic performance along with the vibration response of an industrial scale centrifugal pump (7.5 KW) subjected to different levels of impeller unbalance was experimentally investigated. Extensive testing of the manometric pressure head, flow rate, shaft power and efficiency along with vibration measurements were carried out to evaluate the effects of various levels of impeller unbalance on the pump hydraulic performance. 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 was observed. As the level of unbalance increased, the power required to operate the pump at the designated speed increased by as much as 12%. Also, the PCA found to be a useful tool in comparing the pump vibrations in the field compared to the baseline vibration of the new pump in order to determine the degree of the impeller unbalance. The results of this work can be used to evaluate and monitor the degradation in the pump performance to set the allowable operating conditions and enhance the preventative maintenance programs.

Mechanical noise and vibration control

This presentation is intended to provide basic training for entry-level and early-career acoustical consultants in the area of mechanical equipment noise and vibration control in buildings. The seminar will address the following topics: (1) general design guidelines and noise and vibration criteria; (2) basics of fan, pump, and compressor noise generation and vibration isolation; (3) HVAC ductwork and piping design; (4) evaluating manufacturer sound data; (5) laboratory measurement of mechanical equipment; and (6) conducting field measurements and calculations. References to past projects from the speaker’s 40 + years of consulting experience will be included to emphasize specific points, as appropriate.

Performance of a Long Smooth Multiphase Pump Seal in Different Flow Regimes

Abstract Demanding for multiphase pumps introduces new challenges to the pump design. To prevent machine failures, the performance of the pump (noncontact) annular seal under multiphase conditions needs to be studied. The air addition into the oil flow not only changes the properties of the fluid but also can change the flow status in the seal clearance. The flow status can significantly affect the performance of the pump seal and thereby impact the pump vibration performance. Within the seal annulus, the axial direction flow is dominated by the pressure drop through the seal and can be considered as a Poiseuille flow. The circumferential direction flow is driven by the rotor rotation and can be considered as a Couette flow. The regime of the flow in the seal is controlled by the axial Reynolds number and the circumferential Reynolds number. Published test results on the boundaries between the laminar, transitional, and turbulent regimes in an annular seal are scant. This article will first draw these boundaries based on the test data for long smooth pump seals. Then, this article will show the performance of the long smooth pump seal in different flow regimes. Predictions will also be presented to compare with test results under different flow conditions.

Effects of Increased Tooth Clearance on the Performance of a Labyrinth Seal With Oil-Rich Bubbly Laminar Flow

Abstract In recent years, multiphase pumps have become more and more popular because of the capability to simplify the process, reduce the footprint, and lower the cost. To compensate for the axial thrust force, an annular seal is normally used as a balance piston seal, and the labyrinth seal is one of the choices. A typical labyrinth seal consists of a surface with teeth and a smooth surface. The teeth are either on the rotor or the stator. To protect the machine, one side (either the teeth or the smooth surface) is made of a material that can be safely sacrificed during a rub. After the rub, the teeth clearance is increased. This paper studies the impact of the increased teeth clearance on the performance of the labyrinth seal under oil-rich bubbly flow conditions. The test fluid is a mixture of silicone oil (PSF-5cSt) and air with inlet gas volume fraction (GVF) up to 9%. Tests are conducted with pressure drop (PD) = 34.5 bars, rotor speed ω = 5 krpm, and radial tooth clearance Cr = 0.102 mm and 0.178 mm. Test results show that, for all test conditions (before and after injecting air bubbles into the oil flow), increasing Cr from 0.102 mm to 0.178 mm increases the mass flow rate by about 40% but barely changes the test seal's rotordynamic coefficients, i.e., the increased tooth clearance would not change the pump vibration performance.

A Cost-Aware DNN-Based FDI Technology for Solenoid Pumps

Fluid Pumps serve a critical function in hydraulic and thermodynamic systems, and this often exposes them to prolonged use, leading to fatigue, stress, contamination, filter clogging, etc. On one hand, vibration monitoring for hydraulic components has shown reliable efficiencies in fault detection and isolation (FDI) practices. On the other hand, signal processing techniques provide reliable FDI parameters for artificial intelligence (AI)-based data-driven diagnostics (and prognostics) and have recently attracted global interest across different disciplines and applications. Particularly for cost-aware systems, the choice of diagnostic parameters determines the reliability of an FDI/diagnostic model. By extracting (and selecting) discriminative spectral and transient features from solenoid pump vibration signals, accurate diagnostics across operating conditions can be achieved using AI-based FDI algorithms. This study employs a deep neural network (DNN) for fault diagnosis after a correlation-based selection of discriminative spectral and transient features. To solve the problem of hyperparameter selection for the proposed model, a grid search technique was employed for optimal search for parameters (number of layers, neurons, activation function, weight optimizer, etc.) on different network architectures.The results reveal the high accuracy of a three-layer DNN with ReLU activation function, with a test accuracy of 99.23% and a minimal false alarm rate on a case study.