Fault diagnosis and analysis of main sea water pump based on vibration monitoring in offshore oil field

The main sea water pump is the key equipment for the floating production storage and offloading （FPSO）. Affected by some factors such as hull deformation, sea water corrosion, rigid base and pipeline stress, the vibration value of main sea water pump in the horizontal direction is abnormally high and malfunctions usually happen. Therefore, it is essential to make fault diagnosis of main sea water pump, By conventional off-line monitoring and vibration amplitude spectrum analysis, the fault cycle is found and the alarm value and stop value of equipment are set, which is helpful to equipment maintenance and accident prevention.

Fast Tool for Structural Monitoring of a Pier After Impact of a Very Large Vessel Using Ambient Vibration Analysis

Operational modal analysis is a non-destructive structural investigation that considers only the loads resulting from service conditions.This approach allows the measurement of vibrations on a given structure with no need to interrupt its use.The present work aims to develop a numerical model to represent the global structural behavior of a vessel breasting dolphin using a technique that is simple and cheap in order to obtain a fast answer about the stiffness of a pier after the collision of ships with capacity up to 400,000 t.To determine the modes of vibration,one accelerometer was installed on the breasting dolphin located on the pier and a frequency domain technic was conducted over recorded data to obtain modal parameters of the structure.In situ measurements were compared to data from a finite element model based on the original structural design in order to adapt the model to accurately represent the actual behavior of the system.This allowed a reliable structural analysis that accounted for existing structural damage and imperfections.The results of the experiment presented herein are the numerical characterization of the structure,along with the structural analysis to assess the degree of damage currently observed on the system.It is noted that the dolphin subjected to ship impacts presents a reduction in stiffness of approximately10%and its global damage level can be monitored from now after new accidents.

Vibration analysis of large bulb tubular pump house under pressure pulsations

A 3D finite element model of the Huaiyin third pumping station of the Eastern Route of the South-to-North Water Transfer is described in this paper. Two methods were used in the calculation and vibration analysis of the pumping station in both the time domain and the frequency domain. The pressure pulsation field of the whole flow passage was structured on the basis of pressure pulsations recorded at some locations of the physical model test. Dynamic time-history analysis of the pump house under pressure pulsations was carried out. At the same time, according to spectrum characteristics of the pressure pulsations at measuring points and results of free vibration characteristics analysis of the pump house, the spectrum analysis method of random vibration was used to calculate dynamic responses of the pump house. Results from both methods are consistent, which indicates that they are both reasonable. The results can be used for reference in anti-vibration safety evaluation of the Huaiyin third pumping station.

Analysis of fluid vibration transfer path and parameter sensitivity of swash plate axial piston pump

Taking swash plate axial piston pump as the research object,the mechanism of fluid vibration and transfer rule are analyzed.The pump shell can be assumed as the ultimate recipient of vibration transmission,the path model and differential equations from the fluid to the shell are established.The parameters of the path model are determined by the simulation software,and the mathematical model is solved by the simulation software.And time/frequency domain analysis of vibration acceleration of shell is presented.Based on the different influence of various parameters in the transfer path model on transfer characteristics and vibrational recipients,the time-varying parameters are studied by using sensitivity analysis theory,and the influence of the structural parameters on the vibration characteristics of vibration subject is quantitatively analyzed.The research in the paper provides theoretical basis for vibration analysis and structure parameter optimization of axial piston pump.

Design on Vibration Monitoring and Fault Diagnosis System of Large Water Pump Motor

Large water pump motor,whose operation decides the reliability of the whole production line,plays a very important role.Therefore,its online condition monitoring can help companies better know its operation,process fault analysis and protection.The essay mainly studies and designs large water pump motor′s real time vibration monitoring and fault diagnosis system.The essay completes the systems project design,the establishment of the system and performance test.Eddy-currentsensor,XM-120 vibration module,XM-320 axial translation module,XM-362 temperature module,XM-360 process amount module and XM-500 gateway module are used to measure the axial vibration and displacement of main motors.Laboratory tests prove that the system can meet the requirements of motor vibration monitoring.

Vibration Monitoring and Diagnosis of Pipe-line Pumps on Offshore Platforms

This paper presents the applications of vibration monitoring and a diagnosis technique on the predictive maintenance of pipe line pumps on offshore platforms. The monitored ten pumps are distributed on the past three petroleum platforms of the CACT (C: China offshove Southern; A: Agip; C: Chivron; T: Texaco) Operation Group in the Huizhou oil field. By the periodical vibration survey in recent three years, the typical faults and the vibration features of these pumps have been summarized, which set up the basis for efficient predictive maintenance of this key equipment offshore.

State of the Art Vibration Analysis of Electrical Rotating Machines

Electrical machines are precarious mechanisms in manufacturing practices. A motor failure may yield an unexpected interruption at the industrial plant, with consequences in costs, product quality, and security. To govern the conditions of each part of motor, various testing and monitoring methods have been developed. In this paper, a review on effective fault indicators and vibration based condition monitoring approaches of rotating electrical machines has been accomplished. The determination of the review is to progress the understanding of vibration based analysis, and its use in the Machine Health Monitoring. A variety of analysis was identified to highlight the concept of predictive maintenance in industries. The techniques of vibration analysis were investigated to detect both healthy and fault related signals of rotating machineries.

SVM Algorithm for Vibration Fault Diagnosis in Centrifugal Pump

Vibration failure in the pumping system is a significant issue for indus-tries that rely on the pump as a critical device which requires regular maintenance.To save energy and money,a new automated system must be developed that can detect anomalies at an early stage.This paper presents a case study of a machine learning(ML)-based computational technique for automatic fault detection in a cascade pumping system based on variable frequency drive(VFD).Since the intensity of the vibrational effect depends on which axis has the most significant effect,a three-axis accelerometer is used to measure it in the pumping system.The emphasis is on determining the vibration effect on different axes.For experiment,various ML algorithms are investigated on collected vibratory data through Matlab software in x,y,z axes and performances of the algorithms are compared based on accuracy rate,prediction speed and training time.Based on the proposed research results,the multiclass support vector machine(MSVM)is found to be the best suitable algorithm compared to other algorithms.It has been demonstrated that ML algorithms can detect faults automatically rather than conventional meth-ods.MSVM is used for the proposed work because it is less complex and pro-duces better results with a limited data set.

Structural health monitoring of long-span suspension bridges using wavelet packet analysis

During the service life of civil engineering structures such as long-span bridges, local damage at key positions may continually accumulate, and may finally result in their sudden failure. One core issue of global vibration-based health monitoring methods is to seek some damage indices that are sensitive to structural damage, This paper proposes an online structural health monitoring method for long-span suspension bridges using wavelet packet transform （WPT）. The WPT- based method is based on the energy variations of structural ambient vibration responses decomposed using wavelet packet analysis. The main feature of this method is that the proposed wavelet packet energy spectrum （WPES） has the ability to detect structural damage from ambient vibration tests of a long-span suspension bridge. As an example application, the WPES-based health monitoring system is used on the Runyang Suspension Bridge under daily environmental conditions. The analysis reveals that changes in environmental temperature have a long-term influence on the WPES, while the effect of traffic loadings on the measured WPES of the bridge presents instantaneous changes because of the nonstationary properties of the loadings. The condition indication indices VD reflect the influences of environmental temperature on the dynamic properties of the Runyang Suspension Bridge. The field tests demonstrate that the proposed WPES-based condition indication index VD is a good candidate index for health monitoring of long-span suspension bridges under ambient excitations.

Defect detection in freight railcar tapered-roller bearings using vibration techniques

Currently,there are two types of defect detection systems used to monitor the health of freight railcar bearings in service:wayside hot-box detection systems and trackside acoustic detection systems.These systems have proven to be inefficient in accurately determining bearing health,especially in the early stages of defect development.To that end,a prototype onboard bearing condition monitoring system has been developed and validated through extensive laboratory testing and a designated field test in 2015 at the Transportation Technology Center,Inc.in Pueblo,CO.The devised system can accurately and reliably characterize the health of bearings based on developed vibration thresholds and can identify defective taperedroller bearing components with defect areas smaller than 12.9 cm2 while in service.

Integrated Condition Monitoring of Large Captive Power Plants and Aluminum Smelters

Condition monitoring is implementation of the advanced diagnostic techniques to reduce downtime and to increase the efficiency and reliability.The research is for determining the usage of advanced techniques like Vibration analysis,Oil analysis and Thermography to diagnose ensuing problems of the Plant and Machinery at an early stage and plan to take corrective and preventive actions to eliminate the forthcoming breakdown and enhancing the reliability of the system.Nowadays,the most of the industries have adopted the condition monitoring techniques as a part of support system to the basic maintenance strategies.Major condition monitoring technique they follow is Vibration Spectrum Analysis,which can detect faults at a very early stage.However implementation of other techniques like Oil analysis or Ferrography,Thermography etc.can further enhance the data interpretation as they would detect the source of abnormality at much early stage thus providing us with a longer lead time to plan and take the corrective actions.In Large Captive Power Plants and Aluminium Smelters,Integrated Condition Monitoring techniques play an important role as stoppage of primary system and its auxiliaries(boiler,steam turbine,generator,coal and ash handling plants etc.)results into the stoppage of the entire plant,which in turn leads to loss of productivity.From economical and operational point of view,it is desirable to ensure optimum level of system availability.

Health Monitoring of Dry Clutch System Using Deep Learning Approach

Clutch is one of the most significant components in automobiles.To improve passenger safety,reliability and economy of automobiles,advanced supervision and fault diagnostics are required.Condition Monitoring is one of the key divisions that can be used to track the reliability of clutch and allied components.The state of the clutch elements can be monitored with the help of vibration signals which contain valuable information required for classification.Specific drawbacks of traditional fault diagnosis techniques like high reliability on human intelligence and the requirement of profes-sional expertise,have made researchers look for intelligent fault diagnosis techniques.In this article,the classification performance of the deep learning technique(employing images plotted from vibration signals)is compared with the machine learning technique(using features extracted from vibration signals)to identify the most viable solution for condition monitoring of the clutch system.The overall experimentation is carried out in two phases,namely the deep learning phase and the machine learning phase.Overall,the effectiveness of the pre-trained networks was assessed and compared with machine learning algorithms.Based on the comparative study,the best-performing technique is recommended for real-time application.

Monitoring the Technical Condition of Dams of Hydroelectric Power Plants with an Automated Monitoring and Earthquake Registration System

An approach is described that has been developed for auxiliary monitoring of technical condition of hydropower plant dams. It is based on analysis of changes in dynamic characteristics of dams obtained by an automated monitoring and earthquake registration system that records microseismic vibrations of structures. The configuration of the system as well as the results of seismometric monitoring of the dam of Krasnoyarsk hydroelectric power plant are described. To study behavior of the dam under normal and extreme loads it was proposed to develop a model of the dam with the use of the finite element method.

Dynamics analysis and experiment on the fishtailing type of valveless piezoelectric pump with rectangular vibrator

In recent years, the research and development of piezoelectric pumps have become an increasingly popular topic. Minimization, structure simplification and stronger output become the focus of piezoelectric pumps’ research due to its possible application in MEMS technology. The valveless fishtailing piezoelectric pump, neither a volumetric nor a rotating pump, was invented according to the bionics of fish swimming. With assumption that the head of the fish is fixed while its tail is swinging, fluid would flow toward the end of the tail, achieving the function of a valveless pump. This type of pumps creates a new branch for the piezoelectric pump research, which is proposed for the first time in this paper. The relationship between the flow rates and vibrating frequencies was derived from the interaction between the vibrator and fluid. Numerical simulations with FEM software were conducted to study the first and second vibration modes of the piezoelectric vibrator. The results showed that the maximum amplitude of the vibrator was 0.9 mm at the frequency of 76 Hz for the first vibration mode, while the maximum amplitude of the vibrator was 0.22 mm at the frequency of 781 Hz for the second vibration mode. Experiments were conducted with the Doppler laser vibration measurement system, and the results were compared to those of the FEM simulation. It was shown that in the first vibration mode the piezoelectric vibrator reached its maximum amplitude of about 0.9 mm at the driving frequency of 49 Hz, which gives the flow rate of 2.0 mL/min, in the second vibration mode, the maximum amplitude was about 0.25 mm at the frequency of 460 Hz with the flow rate being 6.4 mL/min.

Design of Vibration Sensor Based on Fiber Bragg Grating

Fiber grating is a kind of new type of fiber optic light source device which has been rapidly changing in the refractive index of the core in recent years. Especially, it can realize the high precision of the external parameters by means of the special structure design and the encapsulation technology [1, 2]. In this paper, a fiber grating vibration sensor which is suitable for vibration monitoring in key areas is designed based on the technical background of vibration monitoring system. The sensor uses a single beam structure and pastes the fiber Bragg grating （FBG） to measure the vibration wavelength on the surface. When the vibration is simply harmonic vibration, the Bragg reflection wavelength will change periodically, and the periodic variation of the wavelength curve can be measured by the fiber grating demodulator, then the correctness of the experimental results is verified. In this paper, through the analysis of the data measured by the demodulator, the MATLAB software is used to verify the data, and the different frequency domains, the modes, and the phase frequency curves are obtained. The measurement range is 0Hz-100Hz, and the natural frequency is 90.6Hz.

Vibration testing of a steel girder bridge using cabled and wireless sensors

Being able to significantly reduce system installation time and cost,wireless sensing technology has attracted much interest in the structural health monitoring(SHM)community.This paper reports the field application of a wireless sensing system on a 4-span highway bridge located in Wayne,New Jersey in the US.Bridge vibration due to traffic and ambient excitation is measured.To enhance the signal-to-noise ratio,a low-noise high-gain signal conditioning module is developed for the wireless sensing system.Nineteen wireless and nineteen cabled accelerometers are first installed along the sidewalk of two neighboring bridge spans.The performance of the wireless sensing system is compared with the high-precision cabled sensing system.In the next series of testing,16 wireless accelerometers are installed under the deck of another bridge span,forming a 4×4 array.Operating deflection analysis is successfully conducted using the wireless measurement of traffic and ambient vibrations.

Physics-based data analysis for wind turbine condition monitoring

This article presents methodologies for improving wind turbine condition monitoring using physics-based data analysis techniques.The unique operating conditions of the wind turbine drivetrain are described,and the complex kinematics of the gearbox is analyzed in detail.The pros and cons of the current wind turbine condition monitoring system(CMS)are evaluated.To improve the wind turbine CMS capability,it is suggested to use linear models with unsteady excitations,instead of using nonlinear and nonstationary process models,when dealing the wind turbine dynamics response model.An analysis is undertaken of the damage excitation mechanisms cause for various components in a gearbox,especially for those associated with lower-speed shafts.Physics(mechanics)-based data analysis methods are presented for different component damage excitation mechanisms.Validation results,using the wind farm and manufacturing floor data,are reported.

基于声纹监测技术的大型泵站机组振动特性研究

声音和振动是反映旋转机械设备运行状态信息的直接载体,根据声纹监测的原理,通过对数据进行采集、预处理、提取特征值,采用卷积神经网络深度学习识别模型,建立大型泵站机组运行状态声纹样本库和模型库,构建泵站机组振动状态的声纹监测系统,实现大型泵站机组运行状态的实时监测。

爆破振动在岩质边坡坡面的放大机制研究

岩质边坡坡面的爆破振动放大现象,影响着边坡爆破振动监测及安全评价的准确性。采用数值模拟方法,研究了边坡坡面的振动放大现象,基于结构动力学原理,根据振型分析理论揭示了边坡坡面振动放大机制。数值模拟结果表明:边坡振动放大现象主要发生在台阶坡顶线附近区域,受台阶突出物几何尺寸及岩体物理力学参数的影响,随着平台宽度增大、台阶高度减小、台阶坡比减小以及岩体工程质量等级的降低,台阶坡顶线位置振动速度峰值相对于台阶坡底线位置的振动放大现象逐渐显著,但第一主应力分布与振动速度峰值分布规律相反,因此为了更准确地进行爆破振动安全评价,建议将监测点布置于台阶坡底线位置。振型分析结果表明:台阶突出物的低阶振型中坡底线位置与坡顶线位置的振动速度峰值之比随着台阶几何尺寸及物理力学参数的变化规律与数值模拟计算结果一致。由此可见:边坡坡面的振动放大效应主要由台阶突出物几何尺寸及岩体物理力学参数决定的低阶振型控制。

工况对双螺杆混输泵振动特性影响实验

为研究工况对双螺杆混输泵振动特性的影响,搭建双螺杆混输泵多通道振动测试系统,测试并分析不同含气率、转速及出口压力下混输泵振动参数。结果表明:排液开始时排液腔瞬时打开诱发射流,射流向竖直向的泵出口偏转从而产生压力脉动并诱发振动,导致泵竖直方向振动加速度有效值高于水平方向和轴向;含气率为7.5%时振动加速度有效值为纯液工况时的1.88倍,随着含气率进一步升高测量值降低;而含气率大于20%时,振动有效值继续升高。在转速为1450r/min时y方向振动加速度有效值是850r/min时的2.95倍;振动加速度有效值随出口压力变化较小。当转速由850r/min升高至1450r/min时,径向垂直方向振动加速度主频由75fn移动至50fn。研究可为提高双螺杆混输泵运行稳定性提供指导。