On the Prediction of Rotating Stall in an Industrial Gas Turbine Compressor

2021 ◽  
Author(s):  
Senthil Krishnababu
Author(s):  
Senthil K. Krishnababu

Abstract An investigation is presented into the computation of rotating stall in an industrial gas turbine compressor using a hybrid whole annulus and single passage computational domain. The objective of this investigation is to demonstrate the use of large-scale unsteady computations with quicker turn-around times in the design cycle to develop and evaluate several variable guide vane schedules and/or bleed settings. This means that subsequent engine test campaign could be carried out with significantly lower test matrix size in terms of the number of variable guide vane schedules and/or the handling bleed settings thus reducing the overall development time and cost. Rotating stall that was measured and characterised during a previous compressor rig test (Krishnababu, et al. [1]) were successfully predicted by large-scale unsteady computations using TurboStream. The predicted number of stall cells and their speed agreed closely with the test data. The methodology validated was applied to predict and mitigate the rotating stall in the development of a compressor for a new gas turbine engine. Using this approach, it was possible to define bleed control system that ensured stall free operation.


1997 ◽  
Vol 119 (2) ◽  
pp. 362-369 ◽  
Author(s):  
V. Dedoussis ◽  
K. Mathioudakis ◽  
K. D. Papailiou

A method for establishing signatures of faults in the rotating blades of a gas turbine compressor is presented. The method employs a panel technique for the calculation of the flow field around blade cascades, with disrupted periodicity, a situation encountered when a blade fault has occurred. From this calculation, time signals of the pressure at a location on the casing wall, facing the rotating blades, are constituted. Processing these signals, in combination with “healthy” pressure signals, allows the constitution of fault signatures. The proposed method employs geometric data, as well as data about the operating point of the engine. It gives the possibility of establishing the fault signatures without the need of performing experiments with implanted faults. The successful application of the method is demonstrated by comparison of signatures obtained by simulation to signatures derived from experiments with implanted blade faults, in an industrial gas turbine.


Author(s):  
E. Loukis ◽  
K. Mathioudakis ◽  
K. Papailiou

A method enabling the automated diagnosis of Gas Turbine Compressor blade faults, based on the principles of statistical pattern recognition is initially presented. The decision making is based on the derivation of spectral patterns from dynamic measurements data and then the calculation of discriminants with respect to reference spectral patterns of the faults while it takes into account their statistical properties. A method of optimizing the selection of discriminants using dynamic measurements data is also presented. A few scalar discriminants are derived, in such a way that the maximum available discrimination potential is exploited. In this way the success rate of automated decision making is further improved, while the need for intuitive discriminant selection is eliminated. The effectiveness of the proposed methods is demonstrated by application to data coming from an Industrial Gas Turbine while extension to other aspects of Fault Diagnosis is discussed.


Author(s):  
Brian Kestner ◽  
Tim Lieuwen ◽  
Chris Hill ◽  
Leonard Angello ◽  
Josh Barron ◽  
...  

This paper summarizes an analysis of data obtained from an instrumented compressor of an operational, heavy duty industrial gas turbine; the goal of the aforementioned analysis is to understand some of the fundamental drivers, which may lead to compressor blade vibration. Methodologies are needed to (1) understand the fundamental drivers of compressor blade vibration, (2) quantify the severity of “events,” which accelerate the likelihood of failure and reduce the remaining life of the blade, and (3) proactively detect when these issues are occurring so that the operator can take corrective action. The motivation for this analysis lies in understanding the correlations between different sensors, which may be used to measure the fundamental drivers and blade vibrations. In this study, a variety of dynamic data was acquired from an operating engine, including acoustic pressure, bearing vibration, tip timing, and traditional gas path measurements. The acoustic pressure sensors were installed on the first four compressor stages, while the tip timing was installed on the first stage only. These data show the presence of rotating stall instabilities in the front stages of the compressor, occurring during every startup and shutdown, and manifesting itself as increased amplitude oscillations in the dynamic pressure measurements, which are manifested in blade and bearing vibrations. The data that lead to these observations were acquired during several startup and shutdown events, and clearly show that the amplitude of these instabilities and the rpm at which they occur can vary substantially.


Author(s):  
John R. Scheibel ◽  
Robert P. Dewey ◽  
Leonard Angello ◽  
Josh Barron

This paper addresses recent industrial gas turbine compressor dependability issues and risk mitigation measures viewed from the end user’s perspective. Industrial reliability-availability-maintainability statistics related to power generation applications are reviewed. Several case histories with specific component issues involving blades and vanes are covered. Case histories are used to summarize field experience, engineering analysis and evaluation of related design and operating modifications as appropriate. Recent progress with setting up a field monitoring demonstration using pressure pulsations, vibration and acoustic emissions is summarized.


Author(s):  
S. D. Grimshaw ◽  
J. Brind ◽  
G. Pullan ◽  
R. Seki

Abstract Loss in axial compressor bleed systems is quantified, and the loss mechanisms identified, in order to determine how efficiency can be improved. For a given bleed air pressure requirement, reducing bleed system loss allows air to be bled from further upstream in the compressor, with benefits for the thermodynamic cycle. A definition of isentropic efficiency which includes bleed flow is used to account for this. Two cases with similar bleed systems are studied: a low-speed, single-stage research compressor and a large industrial gas turbine high-pressure compressor. A new method for characterising bleed system loss is introduced, using research compressor test results as a demonstration case. A loss coefficient is defined for a control volume including only flow passing through the bleed system. The coefficient takes a measured value of 95% bleed system inlet dynamic head, and is shown to be a weak function of compressor operating point and bleed rate, varying by ±2.2% over all tested conditions. This loss coefficient is the correct non-dimensional metric for quantifying and comparing bleed system performance. Computations of the research compressor and industrial gas turbine compressor identify the loss mechanisms in the bleed system flow. In both cases, approximately two-thirds of total loss is due to shearing of a high-velocity jet at the rear face of the bleed slot, one quarter is due to mixing in the plenum chamber and the remainder occurs in the off-take duct. Therefore, the main objective of a designer should be to diffuse the flow within the bleed slot. A redesigned bleed slot geometry is presented that achieves this objective and reduces the loss coefficient by 31%.


Author(s):  
Douglas L. Wenzel ◽  
Jeffrey M. Elmore

The Cooper-Bessemer Rotating Products group of Cooper Energy Services has designed an all-new industrial gas turbine / compressor package based upon the Allison Engine Company 501-KC5 gas generator with a two-stage industrial power turbine. The latest project management techniques were employed to reduce design cycle time while optimizing total product quality, manufacturability, and reliability. The resulting gas turbine / compressor package is a low-risk, technologically conservative approach, designed to avoid the problems often associated with new product development.


Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2708
Author(s):  
Martí de Castro-Cros ◽  
Stefano Rosso ◽  
Edgar Bahilo ◽  
Manel Velasco ◽  
Cecilio Angulo

Maintenance is the process of preserving the good condition of a system to ensure its reliability and availability to perform specific operations. The way maintenance is nowadays performed in industry is changing thanks to the increasing availability of data and condition assessment methods. Soft sensors have been widely used over last years to monitor industrial processes and to predict process variables that are difficult to measured. The main objective of this study is to monitor and evaluate the condition of the compressor in a particular industrial gas turbine by developing a soft sensor following an autoencoder architecture. The data used to monitor and analyze its condition were captured by several sensors located along the compressor for around five years. The condition assessment of an industrial gas turbine compressor reveals significant changes over time, as well as a drift in its performance. These results lead to a qualitative indicator of the compressor behavior in long-term performance.


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