| 摘要 |
The invention relates to a method of detecting and localizing partial rotor-stator rubbing during the operation of a turbine, in which the rotor (1) of the turbine is monitored by means of at least one pair of sensors (3, 30, 4, 40) of the rotor vibrations arranged in one plane of measuring (330, 440) perpendicular to the axis of the rotor (1) and by at least one pair of sensors of the absolute vibrations of the bearings (2, 20). When using this method of processing, synchronically digitalized signals of the sensors (3, 30, 4, 40) of rotor vibrations, first the arithmetic mean of the individual harmonic bands in full spectrum in the frequency domain is calculated, by which means the information about the subharmonic components and their multiples in the full spectrum of these signals is transfered into the frequency band -1 X to 1 X (where X indicates the rotational frequency of the rotor (1)), at the same time is by the calculation of the median estimated the level of the signal noise, with which individual frequency bands of the full spectrum are encumbered, and which is subtracted from the amplitudes in the individual frequency bands of full spectrum of the signals of the sensors. Thus normalized accumulated full spectrum of the signals of the sensors of rotor vibrations is created, in which, subsequently, the amplitude of the predetermined subharmonic component/components of the signals of rotor vibrations is compared with the amplitudes of the frequency components in its proximity determined by the Fourier transform or by approximation with the Fourier series. Simultaneously, the presence of the monitored subharmonic component of the signals of the rotor vibrations in the spectrum of these signals is deduced, on the basis of which subsequently the occurrence of rotor-stator rubbing is deduced. In case of the rubbing occurrence the place/places of the turbine where it takes place is further localized. |
