Gauging and Diagnostics of Turbine-Unit Shaft Lines by Torsional Oscillations

Abstract

We consider the problems of developing the systems for gauging and diagnostics of the technical condition of the shaft lines of the steam-turbine generator sets of nuclear and thermal power plants using torsional vibrations. The requirements for full-time systems of diagnostic monitoring of torsional vibrations are formulated. The measuring schemes and methods to measure torsional vibrations of rotary machines by the time-interval measurement method are analyzed. Their advantages and disadvantages are shown. The reasons causing errors when measuring torsional vibrations are described. A method for measuring torsional vibrations of rotary machines by the time-interval method has been developed, which can serve as an arbitration technique, since it allows for the influence of the largest number of spurious factors and provides the most accurate measurement of torsional vibrations. The reasons for exciting torsional vibrations of the shaft lines of the gas turbine generator sets and the methods of their identification, ways to solve the problem of assessing the stress-strain state of the shaft line in dynamics, and early detection of the shaft line integrity defects during operation are considered.