GAS TURBINE ENGINE MOTORING WITH STARTER AIR VALVE MANUAL OVERRIDE

• US 20180094588A1
• Filed: 09/30/2016
• Published: 04/05/2018
• Est. Priority Date: 09/30/2016
• Status: Active Grant

• Current Assignee: Rtx Corporation
• Original Assignee: United Technologies Corporation (Rtx Corporation)
• Inventors: Clauson, Jesse W., Gelwan, David
• Granted Patent: US 10,787,968 B2
• Time in Patent Office: Days
• CPC Class Codes: F01D 19/02 dependent on temperature of component parts, e.g. of turbine-casing
• CPC Class Codes: F02C 3/04 having a turbine driving a compressor power transmission arrangements F02C7/36; control of working fluid flow F02C9/16
• CPC Class Codes: F02C 7/277 the starter being a separate turbine
• CPC Class Codes: F02C 7/32 Arrangement, mounting, or driving, of auxiliaries
• CPC Class Codes: F05D 2220/50 for auxiliary power units (APU's)
• CPC Class Codes: F05D 2260/85 Starting
• CPC Class Codes: F05D 2270/304 Spool rotational speed

Abstract

A system for gas turbine engine motoring includes an air turbine starter coupled to a gearbox of a gas turbine engine and a starter air valve in fluid communication with the air turbine starter to drive motoring of the gas turbine engine responsive to a regulated pressure from a compressed air source. A manual override of the starter air valve is adjustable to one or more predefined intermediate positions that partially open the starter air valve to limit a motoring speed of the gas turbine engine below a resonance speed of a starting spool of the gas turbine engine responsive to the regulated pressure.

Claims

1. A system for gas turbine engine motoring, the system comprising:

an air turbine starter coupled to a gearbox of a gas turbine engine;

a starter air valve in fluid communication with the air turbine starter to drive motoring of the gas turbine engine responsive to a regulated pressure from a compressed air source; and

a manual override of the starter air valve, the manual override adjustable to one or more predefined intermediate positions that partially open the starter air valve to limit a motoring speed of the gas turbine engine below a resonance speed of a starting spool of the gas turbine engine responsive to the regulated pressure.

2. The system as in claim 1, wherein the compressed air source is an auxiliary power unit, a ground cart, or a cross engine bleed.

3. The system as in claim 1, wherein at least one valve of the compressed air source sets the regulated pressure.

4. The system as in claim 3, further comprising a controller that adjusts the at least one valve of the compressed air source in response to at least one parameter of the gas turbine engine to maintain the motoring speed of the gas turbine engine below the resonance speed.

5. The system as in claim 4, wherein the at least one parameter comprises one or more of:

an engine speed of the gas turbine engine, a starter speed of the air turbine starter, and a starter air pressure.

6. The system as in claim 4, wherein the controller dynamically adjusts the at least one valve based on one or more of:

a pressure change of the compressed air source and a change in a targeted motoring speed of the gas turbine engine.

7. The system of claim 1, wherein the one or more predefined intermediate positions are set by one or more detents.

8. A system of an aircraft, the system comprising:

a donor gas turbine engine operable as a compressed air source to cross bleed a regulated pressure; and

a starting gas turbine engine comprising;

an air turbine starter coupled to a gearbox;

a starter air valve in fluid communication with the air turbine starter to drive motoring of the starting gas turbine engine responsive to the regulated pressure; and

a manual override of the starter air valve, the manual override adjustable to one or more predefined intermediate positions that partially open the starter air valve to limit a motoring speed of the starting gas turbine engine below a resonance speed of a starting spool of the starting gas turbine engine responsive to the regulated pressure.

9. The system of claim 8, wherein at least one valve of the compressed air source sets the regulated pressure.

10. The system of claim 9, wherein further comprising a controller that adjusts the at least one valve of the compressed air source in response to at least one parameter of the starting gas turbine engine to maintain the motoring speed of the starting gas turbine engine below the resonance speed.

11. The system of claim 10, the at least one parameter comprises one or more of:

an engine speed of the starting gas turbine engine, a starter speed of the air turbine starter, and a starter air pressure.

12. The system of claim 10, wherein the controller dynamically adjusts the at least one valve based on one or more of:

a pressure change of the compressed air source and a change in a targeted motoring speed of the starting gas turbine engine.

13. The system of claim 8, wherein the one or more predefined intermediate positions are set by one or more detents.

14. A method for gas turbine engine motoring, the method comprising:

opening a flow path from a compressed air source to a starter air valve in fluid communication with an air turbine starter to drive motoring of a gas turbine engine; and

controlling the compressed air source to provide a regulated pressure to the starter air valve set to a partially open position based on a manual override that is adjustable to one or more predefined intermediate positions that partially open the starter air valve to limit a motoring speed of the gas turbine engine below a resonance speed of a starting spool of the gas turbine engine responsive to the regulated pressure.

15. The method as in claim 14, wherein the compressed air source is an auxiliary power unit, a ground cart, or a cross engine bleed.

16. The method as in claim 14, further comprising setting the regulated pressure by at least one valve of the compressed air source.

17. The method as in claim 16, further comprising adjusting, by a controller, the at least one valve of the compressed air source in response to at least one parameter of the gas turbine engine to maintain the motoring speed of the gas turbine engine below the resonance speed.

18. The method as in claim 17, wherein the at least one parameter comprises one or more of:

an engine speed of the gas turbine engine, a starter speed of the air turbine starter, and a starter air pressure.

19. The method as in claim 17, further comprising dynamically adjusting, by the controller, the at least one valve based on one or more of:

a pressure change of the compressed air source and a change in a targeted motoring speed of the gas turbine engine.

20. The method of claim 14, wherein the one or more predefined intermediate positions are set by one or more detents.