Coupled blade-rotor torsional vibration component and low pressure blade retrofit issues
- Delmarva Power and Light Co., Wilmington, DE (United States). Production Operations
A turbine-generator system may respond to torsional excitation which can occur at both synchronous and twice-synchronous frequencies. If machine response frequencies coincide with these electrical system frequencies, significant rotor and blade stresses can occur. A number of blade failures experienced in the power industry have been attributed to torsional vibration. Therefore, when considering a new system or component retrofit, it is imperative that torsional vibration be addressed. This paper will provide: (1) a review of this issue, (2) updated design and analysis processes that can accurately quantify this problem, and (3) a review of two recent case histories at Delmarva Power and Light Company. The case histories will address a complete low pressure turbine and generator rotor retrofit, along with a low pressure turbine last stage blade retrofit. In both cases, significant changes of torsional dynamic characteristics occurred. In one of the case studies, verification testing was pursued to address concerns raised by analysis.
- OSTI ID:
- 207795
- Report Number(s):
- CONF-951010--; ISBN 0-7918-1488-2
- Country of Publication:
- United States
- Language:
- English
Similar Records
Resolution of torsional vibration issue for large turbine generators
Torsional vibration analysis of turbine-generator-blade coupled system