Method of monitoring gas turbine engine operation

• US 20050261820A1
• Filed: 05/21/2004
• Published: 11/24/2005
• Est. Priority Date: 05/21/2004
• Status: Active Grant

• Current Assignee: Pratt & Whitney Canada Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Pratt & Whitney Canada Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Syed, Yusuf Razl, Feeney, Mark Edward, Leslie, Keith John, Hartropp, Simon John
• Granted Patent: US 7,487,029 B2
• Time in Patent Office: Days
• US Class Current: 701/100
• CPC Class Codes: F01D 19/00 Starting of machines or engines; Regulating, controlling, or safety means in connection therewith warming-up before starting F01D25/10; turning or inching gear F01D25/34
• CPC Class Codes: F05D 2220/50 for auxiliary power units (APU's)
• CPC Class Codes: F05D 2240/12 Fluid guiding means, e.g. vanes
• CPC Class Codes: F05D 2260/80 Diagnostics
• CPC Class Codes: F05D 2270/303 Temperature
• CPC Class Codes: F05D 2270/44 active, predictive, or anticipative
• CPC Class Codes: G07C 5/0816 Indicating performance data, e.g. occurrence of a malfunction

Abstract

A system, method and apparatus for monitoring the performance of a gas turbine engine. A counter value Indicative of the comparison between the engine condition and the threshold condition is adjusted. The aircraft operator is warned of an impending maintenance condition based on the counter value and determines an appropriate course of action.

Claims

1. A method of monitoring the performance of an aircraft-mounted gas turbine engine, the method comprising the steps of:

selecting at least one engine parameter to monitor, wherein the engine parameter is indicative of a deterioration condition of the engine as the engine is operated;

selecting an engine at-limit point corresponding to the parameter;

selecting an engine warn point corresponding to the at-limit point, where the warn point is different than the at-limit point;

monitoring the engine parameter;

sensing a difference in the engine parameter between an actual value and an expected value;

adjusting a counter value based on the engine parameter actual-expected difference sensed;

comparing the counter value to the warn point setting a warning flag indicative of an impending maintenance condition when the counter value meets at least a first criterion based on said comparison; and

indicating to an operator of the aircraft that the warning flag has been set.

2. The method of claim 1, wherein the step of adjusting the counter includes adjusting the counter value based on the magnitude of if the difference sensed.

3. The method of claim 2, wherein the counter is adjusted in a first direction if a difference is sensed, and adjusted in a second direction opposite to the first direction if no difference is sensed.

4. The method of claim 1 further wherein the steps of sensing and adjusting are iterated until the step of setting a warning flag is achieved.

5. The method of claim 1, further comprising the step of altering a flight path of the aircraft from a first path to a second path based on the warning flag indication to thereby select a flight path permitting continued operation of the engine within at least one maintenance limit.

6. The method of claim 5, wherein the second path includes a destination having ambient conditions more favorable to continued operation of the engine than ambient conditions of the first path,

7. The method of claim 1, further comprising the step of providing information to the operator on a remaining operating margin within which the engine may be operated prior to performance of a maintenance operation.

8. The method of claim 7, further comprising the step of altering a flight path of the aircraft from a first path to a second path to thereby operate the engine within the remaining operating margin.

9. The method of claim 8, wherein the second path includes a destination having ambient conditions more favorable to continued operation of the engine than ambient conditions of the first path.

10. The method of claim 1, further comprising the step of advising the operator that engine monitoring data should be reviewed to determine a health condition of the engine.

11. The method of claim 1, wherein the engine condition is selected from a set of engine conditions susceptible to control by reason of a selection of ambient operating environments available to the operator.

12. The method of claim 11, wherein the set of engine conditions Includes at least one of an engine temperature, an engine shaft speed, engine oil pressure and an engine torque value.

13. The method of claim 1, further comprising the step of altering the schedule of a maintenance task for said engine.

14. The method of claim 13, further comprising the step of performing said r scheduled maintenance task.

15. A method of monitoring the performance of an aircraft-mounted gas turbine engine, the method comprising the steps of:

sensing effect of at least one ambient weather condition on at least one engine operating parameter;

comparing the sensed effect against a predetermined threshold condition, wherein the threshold condition is different from an engine-at-limit condition such that when the threshold condition is met continued engine operation is still permitted within a selected operational margin prior to a next related maintenance operation;

warning an operator of the aircraft when the predetermined threshold condition Is met; and

then

selecting at least one of a maintenance task and an operating plan for the aircraft based at least partially on expected ambient conditions at an intended destination to thereby operate the aircraft within the operational margin.

16. The method of claim 15, wherein the step of selecting includes selecting a destination having an ambient condition more favorable to continued operation of the engine than an otherwise-intended destination.

17. The method of claim 16, wherein the ambient weather condition comprises at least one of temperature and pressure.

18. The method of claim 17, wherein the temperature comprises a ground temperature at an airport at which the engine is operated.

19. The method of claim 18, wherein the step of selecting includes selecting a destination having a ground temperature more favorable to continued operation of the engine than an otherwise-intended destination.

20. A method of extending operation of an aircraft-mounted gas turbine engine, the method comprising the steps of:

monitoring a temperature of the engine;

counting at least occurrences of a threshold temperature exceedance and occurrences of a threshold temperature non-exceedance;

when a predetermined count value is achieved, selecting an aircraft flight plan to provide a cool operating environment which thereby extends permissible operation period of the engine before a next engine maintenance event is required.

21. The method of claim 20, wherein the engine comprises an auxiliary power unit, and wherein engine exhaust gas temperature is monitored.

22. The method of claim 21, wherein the flight plan is selected to provide an operating environment expected to have an airport ground temperature below a predetermined temperature value.

23. A system for monitoring the performance of an aircraft-mounted gas turbine engine, the system comprising:

a sensor to monitor an engine parameter and detect a difference in the engine parameter between an actual value and an expected value;

a counter to keep track of a counter value based on engine parameter actual- expected difference sensed;

a comparator to compare the counter value to a warn point corresponding to an at- limit point corresponding to the engine parameter, where the warn point is different than the at-limit point and to set a warning flag indicative of an impending maintenance condition when the counter value meets at least a first criterion based on said comparison; and

an indicator to advise an operator of the aircraft that the warning flag has been set.

24. An apparatus for monitoring the performance of an aircraft-mounted gas turbine engine, the apparatus comprising:

an input for receiving an engine parameter;

computing means for detecting a difference in the engine parameter between an actual value and an expected value;

a memory to keep track of a counter value based on engine parameter actual expected difference sensed;

said computing means for further comparing the counter value to a warn point corresponding to an at-limit point corresponding to the engine parameter, where the warn point Is different than the at-limit point and for setting a warning flag indicative of an impending maintenance condition when the counter value meets at least a first criterion based on said comparison; and

an output for Indicating to an operator of the aircraft that the warning flag has been set.