Power plants – Combustion products used as motive fluid
Reexamination Certificate
2000-02-03
2001-11-27
Casaregola, Louis J. (Department: 3746)
Power plants
Combustion products used as motive fluid
C060S039281
Reexamination Certificate
active
06321525
ABSTRACT:
BACKGROUND
The present invention relates to engine control techniques, and more particularly, but not exclusively, relates to gas turbine engine overspeed detection and remediation.
A sudden loss of load for a gas turbine engine can result in a highly destructive failure if not quickly addressed. This type of load loss can occur, for example, when an engine shaft or associated gearing fails. One way to detect if a load loss has occurred is to monitor for an engine overspeed event. One basic type of overspeed detection compares rotational engine speed to a static limit. When this limit is exceeded, an overspeed condition is declared and engine fueling is consequently reduced or shut off. Unfortunately, when the static limit is set too low, false triggering can occur because of brief transient excursions beyond the overspeed limit. Such false triggering typically results in an unwarranted loss of engine power. On the other hand, when the static limit is set to high, the destructive effects of catastrophic, load loss failures are likely to progress further before the overspeed situation is addressed.
One alternative to address these shortcomings is to vary the overspeed limit with a different parameter more closely associated with catastrophic failure load loss, such as rotational acceleration. However, acceleration-based systems are often very sensitive to noise such as might be caused by power transients, electromagnetic interference, lightning, and the like—once again resulting in false triggers and unwarranted engine power loss. Thus, there is a demand for further contributions in this area of technology.
SUMMARY
One form of the present invention is a unique overspeed a monitoring technique. Other forms include unique systems and methods to detect an unacceptable gas turbine engine overspeed condition.
In another form, rotational speed of a rotating member of a gas turbine engine is determined and an overspeed condition of the gas turbine engine established if the rotational speed exceeds a first speed threshold and a second speed threshold. The first speed threshold varies relative to the second speed threshold in accordance with the rate of change of the rotational speed.
Still another form includes a gas turbine engine with a rotatable member and a sensor to provide a signal corresponding to rotational speed of this member. A control is also included that responds to this signal to detect an overspeed condition of the gas turbine engine if the rotational speed exceeds first and second speed thresholds. The control is operable to determine the first speed threshold as a function of rotational acceleration of the rotatable member. The first speed threshold varies relative to the second speed threshold in accordance with this acceleration. Further, an actuator may be included that responds to the control to reduce the rotational speed when the overspeed condition is detected. Such reduction can include activating a fuel valve to reduce or eliminate the flow of fuel to the engine; however, other actions as would occur to those skilled in the art may alternatively or additionally be performed.
Further forms, embodiments, objects, features, aspects, benefits, and advantages of the present invention shall become apparent from the detailed description and drawings contained herein.
REFERENCES:
patent: 3928962 (1975-12-01), Maker
patent: 3932058 (1976-01-01), Harner et al.
patent: 3939649 (1976-02-01), McCabe
patent: 3956884 (1976-05-01), Eves
patent: 4045955 (1977-09-01), Brannstrom et al.
patent: 4218879 (1980-08-01), Hagman et al.
patent: 4248040 (1981-02-01), Kast
patent: 4302931 (1981-12-01), White et al.
patent: 4423593 (1984-01-01), Zagranski et al.
patent: 4474013 (1984-10-01), Chamberlain
patent: 4478038 (1984-10-01), Cropper et al.
patent: 4528812 (1985-07-01), Cantwell
patent: 4578945 (1986-04-01), Peck et al.
patent: 4593523 (1986-06-01), Hawes
patent: 4845943 (1989-07-01), LaPrad et al.
patent: 4987737 (1991-01-01), Cantwell
patent: 4998949 (1991-03-01), Cantwell
patent: 5134845 (1992-08-01), Romano
patent: 5301499 (1994-04-01), Kure-Jensen et al.
patent: 5440490 (1995-08-01), Summerfield
patent: 5486997 (1996-01-01), Reismiller et al.
patent: 5579632 (1996-12-01), Dutka et al.
patent: 5927064 (1999-07-01), Dyer et al.
patent: 5953902 (1999-09-01), Jerye et al.
Casaregola Louis J.
Rolls-Royce Corporation
Woodard Emhardt Naughton Moriarty & McNett
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