MEASUREMENT METHOD FOR DETECTING DAMAGE TO A TURBINE BLADE AND TURBINE

摘要

A measurement method for early detection of damage to a blade of an impeller of a turbine is provided. During operation, in a rotational direction of the blade along a circumference which surrounds the impeller, at a plurality of points, in each case a plurality of magnetic fields are generated next to one another substantially in an oscillation direction of the blade, which magnetic fields are influenced by a tip of a turbine blade during transit. Positional values of the tip are detected by at the plurality of points. A positional profile of the turbine blade is then formed from the positional values and a frequency is determined from the positional profile. The frequency is compared with defined frequency values. An alarm event is recognized in case of a sudden and/or pronounced change in the frequency. In addition, a turbine is provided which is configured to carry out the method.

主权项

1. A measurement method for the early detection of damage to a blade of an impeller of a turbine, the method comprising
during operation of the turbine, in a rotational direction of the blade along a circumference which surrounds the impeller, at a plurality of points, in each case a plurality of magnetic fields are generated next to one another substantially in an oscillation direction of the blade, which magnetic fields are influenced by a tip of a blade leaf of the blade during transit, wherein, in the turbine, measuring areas are arranged at a plurality of points along the circumference in the direction of rotation, wherein the measuring areas are formed with a plurality of exciter coils and with a plurality of rows of probes arranged next to one another, acquiring, as a result of the influence at the plurality of points, positional values of the tip, forming a positional profile of the blade leaf from the positional values, determining a frequency from the positional profile, comparing the frequency with specific frequency values and in the event of a sudden and/or sharp change in the frequency, detecting an alarm event.