Patent Application
20120214605
The present application relates generally to gas turbine engines and more particularly relates to the use of a torsional damping coupling between a gas turbine engine and a generator to protect the gas turbine engine from generator based fault events.
Gas turbine engines and other types of turbo-machinery are often used to drive loads such as electrical generators. Gas turbines are designed to withstand certain levels of generator based fault events without damage. Such fault events may be defined as out-of-phase synchronizing, short circuits, and the like. Fault events may transmit high torques at high oscillation rates from the generator to the turbine. Generally described, a turbine may be designed to tolerate minor fault events without permanent damage and to tolerate major fault events without failure of the turbine. These fault design requirements, however, may increase the overall size, cost, and weight of the turbine.
Shear couplings have been used in the past in attempts to protect the gas turbine engine from generator based fault events. Shear couplings, however, generally do not provide any benefit during minor fault events and generally require replacement after a major fault event. As such, shear couplings may be of limited effectiveness and long term value.
There is thus a desire for systems and methods for the protection and/or response of a gas turbine engine from generator based fault events. Such improved systems and methods preferably would substantially isolate the gas turbine engine from such fault events and thus permit a reduction in current turbine fault design requirements and costs.
The present application and the resultant patent thus provide a gas turbine engine generator system. The gas turbine engine generator system may include a turbine, a generator, and a shaft. The turbine drives the generator via the shaft. A torsional damping coupling may be positioned about the shaft so as to limit the transmission of torque to the turbine during a generator based fault event.
The present application and the resultant patent further provide a method of operating a gas turbine engine generator system. The method may include the steps of positioning a torsional damping coupling about a shaft between a generator and a turbine, driving the generator by the turbine via the shaft, generating torque in the generator during a fault event, and damping a transmission of torque from the generator to the turbine by the torsional damping coupling.
The present application and the resultant patent further provide a gas turbine engine generator system. The gas turbine engine system may include a turbine, a generator, and a shaft. The turbine drives the generator via the shaft. A torsional damping coupling may be positioned about the shaft. The torsional damping coupling may include an inner part and an outer part separated by a spring set.
These and other features and improvements of the present application will become apparent to one of ordinary skill in the art upon review of the following detailed description when taken in conjunction with the several drawings and the appended claims.
Referring now to the drawings, in which like numerals refer to like elements throughout the several views,
The gas turbine engine 10 may use natural gas, various types of syngas, and/or other types of fuels. The gas turbine engine 10 may be anyone of a number of different gas turbine engines offered by General Electric Company of Schenectady, New York and the like. The gas turbine engine 10 may have different configurations and may use other types of components. Other types of gas turbine engines also may be used herein. Multiple gas turbine engines, other types of turbines, and other types of power generation equipment also may be used herein together.
The gas turbine engine generator system 100 also may include a torsional damping coupling 160 positioned about the shaft 140. The torsional damping coupling 160 may slow the response of the turbine 130 to torque applied by the generator 150 during a fault event. Such fault events typically oscillate at grid frequency and may abate quickly, generally within several seconds. As such, even a relatively short response lag between the generator 150 and the turbine 130 provided by the torsional damping coupling 160 may result in reduced response torque in the turbine 130 and the damage caused thereby.
During torque transmission caused by a generator based fault event, the outer part 180 of the torsional damping coupling 160 may rotate relative to the inner part 170 so as to bend the springs 200. Movement of the springs 200 may push the oil or other fluid from one chamber 210 to another. Generally described, hydraulic friction in the oil flow thus slows the relative movement of the inner part 170 and the outer part 180 so as to provide a momentary damping effect. The torsional damping coupling 160 of this example thus provides oil based and spring based damping. A number of torsional damping couplings 160 may be used herein.
The torsional damping coupling 160 and the operation thereof are described herein for purposes of example only. Many other types and configurations of the torsional damping coupling 160 may be available. An example of the torsional damping coupling 160 may be available from Geislinger GmbH of Salzburg, Austria. Such a torsional damping coupling 160 may be shown in DE 19839470 to Geislinger. Similar devices may be used herein. Other components and other configurations may be used herein.
The use of the torsional damping coupling 160 in the gas turbine engine generator system 100 thus may minimize the impact of both minor and major fault events on the turbine 130 and the other components described herein. Specifically, the torsional damping coupling 160 smoothes the transmission of torque to the turbine 130 cause by generator based fault events. Such a reduction in torque may allow overall turbine design requirements to be relaxed. The size, cost, and weight of the turbine 130 thus may be reduced. Moreover, the entire gas turbine engine generator system 100 may be more reliable with longer component lifetime. The torsional damping coupling 160 may be original equipment or part of a retrofit. Although the use of the gas turbine engine 10 has been described herein, the torsional damping coupling 160 may be used with any type of turbo-machinery and the like.
It should be apparent that the foregoing relates only to certain embodiments of the present application and the resultant patent. Numerous changes and modifications may be made herein by one of ordinary skill in the art without departing from the general spirit and scope of the invention as defined by the following claims and the equivalents thereof.
