Correlation Analysis of Multiple Sensors for Industrial Gas Turbine Compressor Blade Health Monitoring

Abstract

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.

A Review of NDT/Structural Health Monitoring Techniques for Hot Gas Components in Gas Turbines

“…Kestner et al studied the correlations between different installed sensor types on blade vibrations. The authors used acoustic pressure, bearing vibration, tip timing and gas path measurement from an operating machine [14].…”

Experimental Investigation on Hardware and Triggering Effect in Tip-Timing Measurement Uncertainty

“…To avoid this and to increase the performance, safety and stability of gas turbine engines, several techniques have been developed in the last 50 years for Structural Health Monitoring (SHM) and Non-Destructive Testing (NDT) of turbomachinery engines blades [ 3 , 4 ]. Traditionally, a common system to validate the dynamics of rotating blades is the use of strain gauges [ 5 , 6 , 7 ]. However, while they have high accuracy and well established signal processing algorithms, strain gauges have limited lifetimes in high-temperature conditions, are intrusive, have complicated means of transmitting data from a rotating system and the provided information is limited to instrumented blades [ 4 ].…”

“…However, while they have high accuracy and well established signal processing algorithms, strain gauges have limited lifetimes in high-temperature conditions, are intrusive, have complicated means of transmitting data from a rotating system and the provided information is limited to instrumented blades [ 4 ]. Unlike vibration, temperature and ultrasound-based techniques [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ], the Blade Tip-Timing (BTT) approach is one of the most advanced and versatile in situ techniques for axial turbomachinery blade dynamics measurements [ 15 , 16 , 17 ]. The principle of the BTT approach is based on the measurement of instantaneous blade tip deflection by detecting delays or advances in the arrival time of the blade tip at fixed angular positions [ 18 , 19 ].…”

Fault Diagnosis of High‐Speed Train Bogie Based on Synchrony Group Convolutions

“…Hong and Huang [34] evaluated the health condition of the power transformer through the vibration correlation analysis. Kestner et al [35] analysed the correlations for sensors between the pressure measurements and bearing vibration measurements of gas turbine compressor from the view of harmonics. Recent studies suggested that the analytic representation can be another way to obtain time-resolved connectivity of signals.…”