Application of Radio-Wave Motion Transducers to Measure the Parameters of Bending Vibrations of a Turbine Unit Shaft

This work is devoted to the use of radio-wave motion transducers to measure the parameters of bending vibrations of a turbine unit shaft. Various devices for monitoring the vibration parameters of turbine unit elements are considered, their advantages and disadvantages are analyzed. A method is proposed for determining the coordinates of the displacement of the axis of the turbine unit shaft during vibrations, using two radio-wave transducers, with emitters located in two directions perpendicular to the axis of the controlled shaft, taking into account longitudinal and transverse movements in the field of each sensor. A special case of method for monitoring the deformation state of a turbine unit shaft using one peripheral radio-wave transducer is proposed, based on an analysis of the shape of the autodyne signal obtained during the interaction of a radio-wave transducer with the surface of the controlled shaft performing a runout, which allows reducing the level of preparation of the turbine unit body. The criteria for selecting the found parameters of shaft oscillations are determined, based on the conditions of the physical feasibility of the elements of the turbine unit and the possible parameters of oscillatory processes, for both proposed methods. A mathematical model has been developed for the interaction of a radio-wave transducer with the surface of a shaft performing a complex flexural-rotational motion. The results of applying the methodology to measure the parameters of bending vibrations of a turbine unit shaft were checked and the measured parameters of shaft vibrations were compared with the parameters of the oscillatory process specified using a simulator.