Device and method for monitoring rotor blades of a turbine

摘要

A device and a method for monitoring the operational state of rotor blades of a turbine from a position facing the blade tip of a passing rotor blade: A wavesource generates an electromagnetic wave and a wave guide directs the wave towards the blade tip. The waveguide is included in a resonator defining at least one discrete resonance frequency of the wave on the waveguide. An aperture at its front end emits an energy fraction of the wave toward the blade tip. The frequency of the wave is adjusted to the resonance frequency of the resonator at the momentary operation conditions, and a measuring unit compares at least one measurement parameter of the wave directed towards the blade tip with the corresponding measurement parameter of the wave reflected from the blade tip.

主权项

1. A device for monitoring an operational state of rotor blades of a turbine from a position facing a blade tip of a passing rotor blade, the device comprising a wavesource for generating an electromagnetic wave and a waveguide for directing the wave towards the blade tip, wherein said waveguide is included in a resonator defining at least one discrete resonance frequency of the wave on said waveguide and the resonator comprising an aperture at its front end through which an energy fraction of the wave can be emitted towards the blade tip, and the device further comprises a frequency adjusting unit that is configured to set the frequency of the wave to a resonance frequency of said resonator at the momentary operation conditions, and a measuring unit that is configured to compare at least one measurement parameter of the wave emitted towards the blade tip with a corresponding measurement parameter of the wave reflected from the blade tip.