Method for monitoring the operation of a gas turbine

A method, comprising:

• operating a gas turbine having an annular combustor with a burner to produce energy;
• burning of fuel by the burner during the operation of the gas turbine;
• monitoring vibrations of the annular combustor during the operation of the gas turbine by an acceleration sensor coupled on the annular combustor and being excitable to vibrate by vibrations of the annular combustor during the operation of the gas turbine, wherein the monitoring comprising:
• detecting accelerations associated with the annular combustor during the operation of the gas turbine by the acceleration sensor wherein the accelerations include acceleration amplitudes in damaging frequency bands and acceleration amplitudes in non-damaging frequency bands wherein the damaging frequency bands being associated with structure-mechanical damage to the annular combustor from vibration of the annular combustor, and
• forwarding a sensor signal representative of the detected accelerations of the annular combustor to a calculating unit;
• processing, by the calculating unit, the sensor signal;
• subdividing, by the calculating unit, a discrete frequency signal representing the accelerations by means of a frequency band or by means of a plurality of frequency bands into a signal section or a plurality of signal sections on the basis of the sensor signal forwarded during operation of the gas turbine by the acceleration sensor wherein each signal section associated with a respective section time interval,
• wherein the discrete frequency signal represents a corresponding time interval of the sensor signal, and wherein those section time intervals in which only the acceleration amplitudes in the damaging frequency bands which are detected as being greater than an associated frequency band-specific threshold are counted to form a count,
• establishing, by the calculating unit, an overall vibration period based on the count for only the damaging frequency bands;
• and
• comparing the overall vibration period to an overall vibration period threshold wherein if the overall vibration period exceeds the overall vibration period threshold, the gas turbine is caused to be shutdown.