Liquid hammer and the transient operation of hydraulic turbines
- Univ. of California, San Diego, La Jolla, CA (United States)
- EBARA International Corp., Sparks, NV (United States)
The mathematical study of the flow of incompressible fluids through turbomachines such as pumps and turbine generators is difficult because such machines contain irregular shaped channels with variable curved surfaces and variable cross sections. A nonlinear black box model for such flows has been introduced based on conservation of mass, energy and momentum. The model involves the rotation speed x = x(t) of the turbine rotor, the liquid flow rate y = y(t) through the machine, and the hydraulic pressure head between the inlet and outlet of the machine, all considered as functions of time t. Conservation of mass follows directly from the common assumption that the mass flows across the inlet and the outlet are the same. The model has been used for inflow and for outflow turbine generators to study transient pressure pulses due to liquid hammer effects for fixed or variable speed radial flow turbines following a power failure during operation. The methods can also be used directly to study transient liquid hammer pulses following startup for fixed and variable speed pumps, and the model can also be used to study the response of turbomachines to small periodic disturbances during operation near a rated state. In the present work this latter phenomenon, of forced harmonic oscillations, is illustrated for the radial inflow turbine generator. From a practical standpoint the crucial question is the existence or lack of existence of resonant driving frequencies for which small-amplitude periodic driving mechanisms may lead to large responses. The authors show that such resonant frequencies do not exist.
- OSTI ID:
- 318953
- Report Number(s):
- CONF-980426-; TRN: IM9909%%127
- Resource Relation:
- Conference: American power conference, Chicago, IL (United States), 14-16 Apr 1998; Other Information: PBD: 1998; Related Information: Is Part Of Proceedings of the American Power Conference: Volume 60-1; McBride, A.E. [ed.] [Illinois Inst. of Tech., Chicago, IL (United States)]; PB: 613 p.
- Country of Publication:
- United States
- Language:
- English
Similar Records
Heat exchanger temperature response for duty-cycle transients in the NGNP/HTE.
MARITIME GAS-COOLED REACTOR PROGAM QUARTERLY PROGRESS REPORT FOR THE PERIOD ENDING DECEMBER 31, 1959