Vibrations in Turbo Machinery

Paper No. 9

D. R. Smith/J. C. Wachel, Electric Power Research Institute, Symposium on Power Plant Fans: The State of the Art, Indianapolis, IN, October 1981.

Fan vibration problems have been a serious cause of plant unreliability in large fossil-fired power plants and have resulted in operational problems, shutdowns, and reduced generation. The basic causes of most problems are dynamic resonances associated with the system. These have to be identified before practical and effective recommendations can be made for corrective action or design modifications. The most effective solutions can best be determined from computer models which match the measured field data. This paper discusses several cause histories and illustrates methods and instrumentation for analyzing existing fan problems. Experimental techniques are described for defining problem symptoms, and these are related to root causes by the use of data analysis and computer simulation techniques. Computer modeling techniques can then be used to evolve reliable fixes or used in the design stage to simulate interaction between rotor dynamic response and complete system response to prevent potential dynamic problems.

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