Ralph E. Harris

Development of a Knowledge Based Advisory System Based on Vibration of a Peaking Gas Turbine

This paper describes the process of knowledge development and interpretation for a particular model of power generation combustion turbine and generator. The knowledge derives from three sources: fundamental understanding of rotordynamics; the experience of experts in troubleshooting this particular turbine; and in-depth analysis of vibration data acquired during every start-up and run of several examples. The data acquisition system is operated via modem from any phone tine to provide operational data for review.The knowledge is to be applied in two ways. A Post Trip Analysis will provide the operator with advice on what to do when the unit trips, based upon the data obtained during the tripped run and previously acquired characteristics. The Post Trip Analysis will have knowledge which, when compared with the acquired data factors about vibration, and historical characteristics of the specific machine or the fleet, will give a recommended action. This application is designed to be available moments after the trip has occurred.The second application of knowledge is for health assessment. A software module will automatically analyze each day’s data when the file is completed. The volume of data is reduced to a smaller, very descriptive set of data which is saved and compared with previous runs. These analyses are to be performed at the two critical speeds of the turbine and generator, as well as the normal running speed. One planned test for health assessment is to seek deviations: characteristics which fall outside the statistically normal range for the unit in question; characteristics which fall outside the desirable range based on expert opinion; and distinct unexplained changes during a run.The paper illustrates the development and application of the knowledge base.Copyright

Remote Condition Monitoring of a Peaking Gas Turbine

This paper illustrates how software and hardware for telecommunications and data acquisition enable cost-effective monitoring of peaking gas turbines using personal computers. It describes the design and evaluation of a system which transmits data from each start-up and shutdown over 1,500 miles to a monitoring computer. It presents system structure, interfaces, data content, and management. The system captures transient sequences of acceleration, synchronization, loading, thermal stabilization, steady operation, shutdown and cooldown; it yields coherent sets of speed, load, temperature, journal eccentricity, vibration amplitude, and phase at intervals appropriately spaced in time and speed. The data may be used to characterize and identify operational problems.© 1991 ASME