Table of Contents
5.1 Technical monitoring of gas turbines
If we compare our car with that in former days, the electronic monitoring of the technical functions has a central significance. Whatever it is, the closing of the seat belts, the condition of the brakes or the fill level of the windscreen washer. Everything is alredy checked at the start of the car and discovered deviations displayed. That is also true during driving. Naturally the many informations can make insecure, expecially because there is always the suspicion of a malfunction of the electronic itself or of probes. From experience this is not so unjustified.
Not only that we have at the display everything in mind, in the background the data respectively events are additional stored. Later they can be read by the specialists with suitable computer programs. This means, we are shepherded by electronics but also dependent. Where, at times of the mechanic signal transmission, a failure in the indicating device did not paralyse the whole car, today even at one single erroneous inpulse with the danger of a breakdown of the whole car, that it must be towed. So we experience the old worldly wisdom: when there is much light there are also shadows. Therefore reliability and the stability of the monitoring system is essential.
A comparable maxim also applies to the operator of a gas turbine. Reliability, competent analysis and evaluation of the data are of high importance for the quality of monitoring.
The technical monitoring of a gas turbine by using probes can be carried out in different ways. The continued monitoring (condition monitoring, Chapter 5.1.1) replaces a random sampling in regular time intervals. Following monitoring methods are typical:
- Control of the oil system for
- chips and contaminations (magnetic chip detektor, "Ill. 3.5-5"),
- pressure,
- temperature.
- Vibration monitoring, especially for unbalances, rubbing processes and bearing problems ( "Ill. 5.1.2-1").
- Particles in the exhaust gas stream result of critical rubbing processes and component failures.
- Analysis of the gas stream data throughout the whole engine (gas path analysis, "Ill. 5.1-2").
- Temperature of the high pressure turbine blading (pyrometer, "Ill. 3.3.3-1" and "Ill. 3.3.3-2").
- Delivered power/performance respectively torque at the shaft.
- Speed (revolutions) control of the rotor shafts.
