scholarly journals Pulsation and Vibration Measurement on Stator Side for Turbocharger Turbine Blade Vibration Monitoring

Author(s):  
Takashi Ando

Mechanically robust turbine design with respect to blade vibration is challenging when dealing with nozzle-ring fouling and wear. Especially for engines operating with heavy fuel oil (HFO), the nozzle rings of the turbocharger turbines are prone to severe degradation in terms of contamination with unburned fuel deposits. This contamination will lead to an increased excitation of blade resonances in comparison to the nominal design. Due to the statistical character of contamination, long-term monitoring of blade vibration amplitudes would be beneficial. In the harsh environment of HFO operation, however, conventional blade vibration measurement techniques, such as those using strain gauges or blade tip timing, cannot work reliably for a long period. Thus, the objective of this research is to develop a method that enables the monitoring of turbine blades using pulsation or vibration sensors installed on the stator side. Almost a dozen turbines, both radial and axial, have been examined in order to determine a proper measurement chain/position and analytical method. Even though the challenges specific to the turbocharger turbine application—that high-frequency (up to 50 kHz) acoustic radiation from turbine blades has to be detected by a sensor on the stator side—were demanding, in the course of the investigations several clear examples of turbine blades engine-order resonance detection were gathered. Finally, the proposed method has been tested successfully in a power plant for over one year.

2009 ◽  
Vol 147-149 ◽  
pp. 530-541 ◽  
Author(s):  
Miroslaw Witoś ◽  
Ryszard Szczepanik

The intended aim of the paper was to present a short review of more than 15 years of experience of ITWL in the field of applying the signal of actual rotational speed (aperiodic and oscillation components thereof) to the expert diagnosing of aero-engines, including identification of low- and high-cycle fatigue (LCF, HCF) of critical structural members. What has been presented is some essential metrological bearings of the non-contact technique of measuring the engine’s rpm with some flexible key phasors (i.e. vibrating compressor/turbine blades). Also, methods of numerical analysis of measuring signals, in use nowadays, have been discussed. With the jet engine of the SO-3 type (in use on the TS-11 “Iskra” combat trainer) as an example, are discussed algorithms of both the identification of disadvantageous aeromechanical effects (energy state of the engine - i.e. the source of accelerated HCF wear of structural components) and the early detection of symptoms of fatigue failures to compressor blades and the bearing system. The discussed problems have been illustrated with examples selected as to emphasise practicalities of applying a new source of diagnostic information to ‘actively’ control the process of fatigue wear (HCF + LCF) of engine components and to forecast the engine health/maintenance status.


Author(s):  
B. O. Al-Bedoor

Blade vibration has been recognized as one major and costly cause of failure in turbo-machinery. Its vibration measurement has attracted many investigators where until now there is no single reliable approach can be identified. Blade vibration measurement techniques can be classified into two broad categories, namely; (1) the direct approach that includes using strain gages, optical/laser methods, etc., to monitor directly the blade motion at one or more points on the blade span, (2) the indirect approach by extracting some vibration information form the lateral main rotor vibration and the casing/bearing cap vibration, pressure fluctuations, performance monitoring and thermal changes. Recently, a new indirect method has received attention of investigators which is monitoring the torsional vibration of the main rotor. This technique has been investigated by theoretical and experimental studies. The direct and indirect techniques are described in this survey paper and advantages and draw backs are discussed. From the results of this survey it seems that the indirect approach using the torsional vibration measurement is the most promising among all indirect techniques and further theoretical and experimental investigations are recommended.


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Haonan Guo ◽  
Yongmin Yang ◽  
Fengjiao Guan ◽  
Haifeng Hu ◽  
Guoji Shen ◽  
...  

During the working process of the turbine, some types of faults can cause changes in the vibration characteristics of the blades. The real-time vibration monitoring of the blades is of great significance to the stable operation and state-based maintenance. Torsional vibration is a kind of blade vibration modes and results in failures such as cracks easily. Thus, it is important to measure it due to the harmfulness of torsional vibration. Firstly, the principle of blade tip timing (BTT) is introduced, and the models of the blade are built to analyze the characteristics of torsional vibration. Then, the compressed sensing theory is introduced, and its related parameters are determined according to the measurement requirements. Next, based on the condition that the blade rigidity axis is not bent and bent, respectively, the layout method of sensors is proposed and the numerical simulation of the measurement process is performed. The results of the above two types of numerical simulation verify the proposed measurement method. Finally, by analyzing the influencing factors of measurement uncertainty, the optimization method of sensors’ layout is further proposed. This study can provide important theoretical guidance for the measurement of blade torsional vibration.


Author(s):  
Radosław Przysowa

A tip-timing system is used in a coal power station to investigate and mitigate excessive blade vibrations in the exit stage of the low-pressure steam turbine. There are presented hardware and software solutions used to monitor blade responses as well as the analyses of amplitude and frequency trends observed during the 5-year collaborative project, including operation at the nominal speed and during the shutdowns and start-ups. The transition from data acquisition to the embedded system with the partial reuse of tip-timing algorithms and LabView code is demonstrated. The proposed system processes the data coming from the turbine blades in real time and operates autonomously or under the supervision of the PC-based client program connected to the network. Acquired data are stored in a cyclic buffer and can be transferred to the host. The stack pattern is used to distinguish blades and calculate rotating reference. Tip deflection is analysed statistically and evaluated against defined reference patterns.


Author(s):  
Laís A. Nascimento ◽  
Marilda N. Carvalho ◽  
Mohand Benachour ◽  
Valdemir A. Santos ◽  
Leonie A. Sarubbo ◽  
...  

2007 ◽  
Vol 2007 ◽  
pp. 1-10 ◽  
Author(s):  
Shijie Guo

This paper demonstrates the investigations on the blade vibration of a radial inflow micro gas turbine wheel. Firstly, the dependence of Young's modulus on temperature was measured since it is a major concern in structure analysis. It is demonstrated that Young's modulus depends on temperature greatly and the dependence should be considered in vibration analysis, but the temperature gradient from the leading edge to the trailing edge of a blade can be ignored by applying the mean temperature. Secondly, turbine blades suffer many excitations during operation, such as pressure fluctuations (unsteady aerodynamic forces), torque fluctuations, and so forth. Meanwhile, they have many kinds of vibration modes, typical ones being blade-hub (disk) coupled modes and blade-shaft (torsional, longitudinal) coupled modes. Model experiments and FEM analysis were conducted to study the coupled vibrations and to identify the modes which are more likely to be excited. The results show that torque fluctuations and uniform pressure fluctuations are more likely to excite resonance of blade-shaft (torsional, longitudinal) coupled modes. Impact excitations and propagating pressure fluctuations are more likely to excite blade-hub (disk) coupled modes.


2017 ◽  
Vol 68 ◽  
pp. 203-215 ◽  
Author(s):  
Dionisis Stefanitsis ◽  
Ilias Malgarinos ◽  
George Strotos ◽  
Nikolaos Nikolopoulos ◽  
Emmanouil Kakaras ◽  
...  

1996 ◽  
Vol 26 (2) ◽  
pp. 2241-2250 ◽  
Author(s):  
M.A. Byrnes ◽  
E.A. Foumeny ◽  
T. Mahmud ◽  
A.S.A.K. Sharifah ◽  
T. Abbas ◽  
...  

Author(s):  
F. Mikaela Nordborg ◽  
Diane L. Brinkman ◽  
Gerard F. Ricardo ◽  
Susana Agustí ◽  
Andrew P. Negri

Author(s):  
Akili D. Khawaji ◽  
Jong-Mihn Wie

The most popular method of controlling sulfur dioxide (SO2) emissions in a steam turbine power plant is a flue gas desulfurization (FGD) process that uses lime/limestone scrubbing. Another relatively newer FGD technology is to use seawater as a scrubbing medium to absorb SO2 by utilizing the alkalinity present in seawater. This seawater scrubbing FGD process is viable and attractive when a sufficient quantity of seawater is available as a spent cooling water within reasonable proximity to the FGD scrubber. In this process the SO2 gas in the flue gas is absorbed by seawater in an absorber and subsequently oxidized to sulfate by additional seawater. The benefits of the seawater FGD process over the lime/limestone process and other processes are; 1) The process does not require reagents for scrubbing as only seawater and air are needed, thereby reducing the plant operating cost significantly, and 2) No solid waste and sludge are generated, eliminating waste disposal, resulting in substantial cost savings and increasing plant operating reliability. This paper reviews the thermodynamic aspects of the SO2 and seawater system, basic process principles and chemistry, major unit operations consisting of absorption, oxidation and neutralization, plant operation and performance, cost estimates for a typical seawater FGD plant, and pertinent environmental issues and impacts. In addition, the paper presents the major design features of a seawater FGD scrubber for the 130 MW oil fired steam turbine power plant that is under construction in Madinat Yanbu Al-Sinaiyah, Saudi Arabia. The scrubber with the power plant designed for burning heavy fuel oil containing 4% sulfur by weight, is designed to reduce the SO2 level in flue gas to 425 ng/J from 1,957 ng/J.


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