scholarly journals TECHNIQUE OF PROCESSING OF VIBRATION MONITORING DATA, RECEIVED BY THE USE OF MICROELECTROMECHANICAL SYSTEMS

2019 ◽  
Vol 22 (2) ◽  
pp. 38-48
Author(s):  
B. A. Chichkov
Keyword(s):  
Gas Turbines ◽  
Microelectromechanical Systems ◽  
Vibration Characteristics ◽  
Technical State ◽  
Vibration Monitoring ◽  
Microelectromechanical Devices ◽  
Simultaneous Control ◽  
Diagnostic Potential ◽  
Additional Equipment ◽  
Aviation Engines

During the operation of such machines as aviation engines and land based gas turbines, the obligatory vibration monitoring is carried out which is focused on the prevention of their possible damages and destructions during the work on resonant modes or because of material fatigue. Nowadays, as a rule, the standard or additional equipment is used for such control which includes as a component various types of one-axial vibration gauges. In most cases, the control is carried out continuously, and the frequency of registration can differ from several values for a flight to several values in a second. The data received during routine vibration monitoring is peak values of vibrations. They are diagnosed, using the pre-start control and some ways of fit and the tendency of changes of vibration during the operation. Microelectromechanical systems gaining now the increasing distribution (MEMS), as a rule, allow to obtain the data about vibro-acceleration without giving data about the frequency vibration characteristics. But also the regular equipment of vibrational control used during the operation of considered machines does not give data about the frequency vibration characteristics. However, microelectromechanical devices allow to obtain the data with the essential higher frequency of sample rate (in tens and hundreds times) in comparison with mass equipment used now for control, and to carry out the simultaneous control of vibration on three axes using one gauge. Apart from the vibration peak value the position relative to a reference point is fixed. Does the information received according to mentioned above features have better diagnostic potential? Will the array dimension received during data verification be an obstacle to the operational processing? Materials of the present article are an attempt to give answers to these questions and to make representation about possibility and features of an estimation of a technical state of machines by the results of processing of time series vibro-accelerations received with the use of such processing microelectromechanical systems. It is represented that the way of data processing of vibrating monitoring considered in the article at sufficient simplicity of realization allows to solve the problem of an estimation of a technical state of monitoring item.

Error Considerations for Turbine-Generator Torsional Vibration Monitoring

2020 ◽  
Author(s):  
Jindrich Liska ◽  
Jan Jakl ◽  
Sven Kunkel
Keyword(s):  
Power Systems ◽  
Torsional Vibration ◽  
Gas Turbines ◽  
Measurement Errors ◽  
Power Plants ◽  
Signal To Noise Ratio ◽  
Vibration Monitoring ◽  
Turbine Generator ◽  
Turbine Generators ◽  
Incremental Encoder

Abstract Turbine-generator torsional vibration is linked to electrical events in the power grid by the generator air-gap torque. Modern power systems are subject to gradual transformation by increasing flexibility demands and incorporation of renewable resources. As a result, electrical transient events are getting more frequent and thus torsional vibration is getting more and more attention. Especially in the case of large steam and gas turbines torsional vibration can cause material fatigue and present a hazard for safe machine operation. This paper freely builds on previous work, where a method for torsional vibration evaluation using an incremental encoder measurement was presented, in that it supplements error considerations to this methodology. Measurement errors such as precision of the rotor encoder manufacturing, choice of the proper sensor, its signal to noise ratio and the error of instantaneous velocity computation algorithm are analyzed. The knowledge of these errors is essential for torsional vibration as there is an indirect and relatively complicated path from the measurement to the final torsional vibration results compared to other kinds of vibration. The characteristics of particular errors of the processing chain are validated both on experimental data from a test rig as well as field data measured on turbine-generators in power plants.

A Review of Vibration Monitoring as a Diagnostic Tool for Turbine Blade Faults

2012 ◽  
Vol 229-231 ◽  
pp. 1459-1463 ◽  
Author(s):  
Ahmed M. Abdelrhman ◽  
M. Salman Leong ◽  
Somia Alfatih M. Saeed ◽  
Salah M. Ali Al-Obiadi Al Obiadi
Keyword(s):  
Neural Networks ◽  
Signal Processing ◽  
Fuzzy Logic ◽  
Turbine Blade ◽  
Gas Turbines ◽  
Processing Method ◽  
Vibration Monitoring ◽  
Signal Processing Method ◽  
Detection And Diagnosis ◽  
Model Based Analysis

Vibration monitoring is widely recognized as an effective tool for the detection and diagnosis of incipient failures of gas turbines. This paper presents a review of vibration based methods for turbine blade faults. Methods typically involved analysis of blade passing frequencies, and extraction of dynamic signals from the measured vibration response. This includes frequency analysis, wavelet analysis, neural networks and fuzzy logic and model based analysis. The literature reviewed showed that vibration could detect most types of blade faults on the basis that dynamic signals are correctly extracted using the most appropriate signal processing method.

Development of a Case Vibration Measurement System for the DC-990 Gas Turbine

1984 ◽  
Vol 106 (4) ◽  
pp. 935-939
Author(s):  
H. A. Kidd
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Cost Effective ◽  
Industrial Applications ◽  
Vibration Monitoring ◽  
Vibration Measurement ◽  
Monitoring Systems ◽  
Development Programs ◽  
Field Service ◽  
Service Staff

The continued use of gas turbines in industrial applications and increased customer desires for trend analysis has led gas turbine suppliers to develop sophisticated, reliable, cost-effective vibration monitoring systems. This paper discusses the application of case vibration monitoring systems and the design criteria for each component. Engine installation, transducer mounting brackets, types of transducers, interconnecting cables and connectors, charge amplifiers, and signal conditioning and monitoring are considered. Examples are given of the benefits experienced with the final system in several of Dresser Clark’s engine development programs, by manufacturing and production testing, and by Dresser’s field service staff.

Time-Resolved Micro-Raman Thermometry for Microsystems in Motion

2008 ◽  
Vol 130 (12) ◽  
Author(s):  
Justin R. Serrano ◽  
Sean P. Kearney
Keyword(s):  
Microelectromechanical Systems ◽  
Diagnostic Technique ◽  
Temperature Measurements ◽  
Transient Temperature ◽  
Raman Signal ◽  
Periodic Signal ◽  
Fast Time ◽  
Time Resolved ◽  
Microelectromechanical Devices ◽  
Reliable Temperature

Micro-Raman thermometry has been demonstrated to be a feasible technique for obtaining surface temperatures with micron-scale spatial resolution for microelectronic and microelectromechanical systems (MEMSs). However, the intensity of the Raman signal emerging from the probed device is very low and imposes a requirement of prolonged data collection times in order to obtain reliable temperature information. This characteristic currently limits Raman thermometry to steady-state conditions and thereby prevents temperature measurements of transient and fast time-scale events. In this paper, we discuss the extension of the micro-Raman thermometry diagnostic technique to obtain transient temperature measurements on microelectromechanical devices with 100 μs temporal resolution. Through the use of a phase-locked technique we are able to obtain temperature measurements on electrically powered MEMS actuators powered with a periodic signal. Furthermore, we demonstrate a way of obtaining reliable temperature measurements on micron-scale devices that undergo mechanical movement during the device operation.

Recent Developments in Vibration Monitoring and Diagnostics for Aeroderivative Gas Turbines

1985 ◽  
Author(s):  
James C. Adams
Keyword(s):  
Gas Turbines ◽  
High Efficiency ◽  
Industrial Applications ◽  
Vibration Monitoring ◽  
Monitoring Systems ◽  
Monitoring Methods ◽  
Reliable Monitoring ◽  
Recent Developments ◽  
Monitoring And Diagnostics ◽  
Processing Techniques

Industrial aeroderivative gas turbines are becoming increasingly popular for use in both on-shore and off-shore installations. The characteristics of these machines — high efficiency in simple cycle operation, small size, and light weight — make them ideal for industrial applications. As the aeroderivative gas turbine has become more widely used, the need for more reliable monitoring methods has become increasingly apparent. Traditional velocity transducer based seismic monitoring systems have had several shortcomings when applied to aeroderivative gas turbines. One of these problems was nuisance alarms due to increasing transducer noise output. Another was not detecting increasing casing vibration because of transducer deterioration. Overcoming these problems has required advances in transducer technology as well as changes in signal processing techniques. This paper describes the technology and techniques used in new seismic vibration monitoring systems.

scholarly journals Effect of Temperature Variation on Vibration Monitoring of Prestressed Concrete Girders

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Thanh-Canh Huynh ◽  
Young-Hwan Park ◽  
Jae-Hyung Park ◽  
Dong-Soo Hong ◽  
Jeong-Tae Kim
Keyword(s):  
Spectral Density ◽  
Temperature Variation ◽  
Prestressed Concrete ◽  
Vibration Characteristics ◽  
Vibration Monitoring ◽  
Effect Of Temperature ◽  
Concrete Girders ◽  
Power Spectral ◽  
Coefficient Corrélation ◽  
Prestressed Concrete Girders

The effect of temperature variation on vibration monitoring of prestressed concrete (PSC) girders is experimentally analyzed. Firstly, vibration features such as autoregressive (AR) coefficient, correlation coefficient of power spectral density (CC of PSD), natural frequency, and mode shape are selected to estimate the effect of temperature variation on vibration characteristics of PSC girders. Secondly, vibration experiments on a lab-scale PSC girder are performed under the condition of temperature variation. Finally, the vibration features with respect to the temperature variation are analyzed to estimate the effect of temperature in vibration characteristics of the PSC girder.

Polycrystalline Silicon Films for Microelectromechanical Devices

1995 ◽  
Vol 403 ◽  
Author(s):  
H. Kahn ◽  
S. Stemmer ◽  
R. L. Mullen ◽  
M. A. Huff ◽  
A. H. Heuer
Keyword(s):  
Residual Stress ◽  
Polycrystalline Silicon ◽  
Microelectromechanical Systems ◽  
Device Fabrication ◽  
Process Equipment ◽  
Boron Doped ◽  
Microelectromechanical Devices ◽  
Polysilicon Films ◽  
Polycrystalline Silicon Films

AbstractPolycrystalline silicon is the most widely used structural material for surface micromachined microelectromechanical systems (MEMS). There are many advantages to using thick polysilicon films; however, due to process equipment limitations, these devices are typically fabricated from polysilicon films less than 3 μm thick. In this work, microelectromechanical test structures were designed and processed from thick (up to 10 μm) in situ boron-doped polysilicon films. The elastic modulus of these films was about 150 GPa, independent of film thickness. The thermal oxidation of the polysilicon induced a compressive stress into the top surface of the films, which was detected as a residual stress in the polysilicon after the device fabrication was complete.

scholarly journals Binary Cycle Gas Fired Turbine for Gas Compression Service

1962 ◽  
Author(s):  
Adrian W. McAnneny
Keyword(s):  
Gas Turbine ◽  
Centrifugal Compressor ◽  
Gas Turbines ◽  
High Speed ◽  
Waste Heat ◽  
Low Cost ◽  
Main Line ◽  
Gas Compression ◽  
Binary Cycle ◽  
Additional Equipment

Three years ago a survey was made of the various prime movers available to the pipeline industry for gas compression. This survey included gas turbines and two and four-cycle reciprocating gas engines. The purpose of this study was to determine which of the existing equipments would be most economical and whether or not there was a need for the development of additional equipment. As a result of this economic study, it appeared there was a definite requirement in the industry for a high-speed, low-cost, gas turbine-centrifugal compressor unit for both field and main-line-station gas compression. As a result of the studies two gas-turbine-driven centrifugal compressor units were placed in operation early in 1960 at Cypress Station near Houston, waste-heat recovery systems being installed in the summer of 1961. Performance tests were satisfactory and subsequently six small gas-engine-driven compressor units have been installed at two main-line compressor stations.

General Interpolated Fast Fourier Transform: A New Tool for Diagnosing Large Rotating Machinery

2004 ◽  
Vol 127 (4) ◽  
pp. 351-361 ◽  
Author(s):  
D. F. Shi ◽  
L. S. Qu ◽  
N. N. Gindy
Keyword(s):  
Fourier Transform ◽  
Fast Fourier Transform ◽  
Gas Turbines ◽  
Transient Behavior ◽  
Rotating Machinery ◽  
Vibration Monitoring ◽  
New Approach ◽  
Maintenance Program ◽  
Window Functions ◽  
Run Up

Vibration monitoring and diagnosis of rotating machinery is an important part of a predictive maintenance program to reduce operating and maintenance costs. In order to improve the efficiency and accuracy of diagnosis, the general interpolated fast Fourier transform (GIFFT) is introduced in this paper. In comparison to present interpolated fast Fourier transform, this new approach can deal with any type of window functions and possesses high accuracy and robust performance, especially coping with a small number of sampling points. Then, for the purpose of rotating machinery diagnosis, the harmonic vibration ellipse and orbit is reconstructed based on the GIFFT to extract the features of faults and remove the interference from environmental noise and some irrelevant components. This novel scheme is proving to be very effective and reliable in diagnosing several types of malfunctions in gas turbines and compressors and characterizing of the transient behavior of rotating machinery in the run-up stage.

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