ALTERNATING STARTER USE DURING MULTI-ENGINE MOTORING

• US 20180022465A1
• Filed: 07/18/2017
• Published: 01/25/2018
• Est. Priority Date: 07/21/2016
• Status: Active Grant

• Current Assignee: Rtx Corporation
• Original Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Gelwan, David, Clauson, Jesse W., Schwarz, Frederick M.
• Granted Patent: US 10,633,106 B2
• Time in Patent Office: Days
• CPC Class Codes: B64D 31/12 for equalising or synchronising power plants
• CPC Class Codes: F01D 19/02 dependent on temperature of component parts, e.g. of turbine-casing
• CPC Class Codes: F02C 7/26 Starting; Ignition
• CPC Class Codes: F02C 7/268 Starting drives for the rotor , acting directly on the rotor of the gas turbine to be started
• CPC Class Codes: F02C 7/27 Fluid drives turbine starters F02C7/277
• CPC Class Codes: F02C 7/275 Mechanical drives
• CPC Class Codes: F02C 7/277 the starter being a separate turbine
• CPC Class Codes: F02C 9/00 Controlling gas-turbine plants; Controlling fuel supply in air- breathing jet-propulsion plants controlling air intakes F02C7/057; controlling turbines F01D; controlling compressors F04D27/00; controlling in general G05
• CPC Class Codes: F02C 9/18 by bleeding, bypassing or acting on variable working fluid interconnections between turbines or compressors or their stages F02C3/113 takes precedence
• CPC Class Codes: F05D 2220/323 for aircraft propulsion, e.g. jet engines
• CPC Class Codes: F05D 2220/50 for auxiliary power units (APU's)
• CPC Class Codes: F05D 2240/40 Use of a multiplicity of similar components
• CPC Class Codes: F05D 2260/85 Starting
• CPC Class Codes: F05D 2270/304 Spool rotational speed

Abstract

A system is provided for alternating starter use during multi-engine motoring in an aircraft. The system includes a first engine starting system of a first engine and a controller. The controller is operable to coordinate control of the first engine starting system to alternate use of power from a power source relative to use of the power by one or more other engine starting systems of the aircraft while maintaining a starting spool speed of the first engine below a resonance speed of the starting spool during motoring of the first engine.

Claims

1. A system for alternating starter use during multi-engine motoring in an aircraft, the system comprising:

a first engine starting system of a first engine; and

a controller operable to coordinate control of the first engine starting system to alternate use of power from a power source relative to use of the power by one or more other engine starting systems of the aircraft while maintaining a starting spool speed of the first engine below a resonance speed of the starting spool during motoring of the first engine.

2. The system as in claim 1, wherein control of the first engine starting system comprises intermittently accelerating and decelerating the starting spool of the first engine during motoring.

3. The system as in claim 2, wherein acceleration and deceleration of one or more other engines of the aircraft during motoring is performed in an alternating sequence with respect to the first engine.

4. The system as in claim 1, wherein timing of coordinated control of the first engine starting system and the one or more other engine starting systems is determined based on a plurality of performance parameters that are based on one or more of:

an ambient condition, performance limitations of a power source and each starter driven by the power source, engine drag, and parasitic factors.

5. The system as in claim 4, wherein the performance parameters are determined based on one or more of:

an ambient air temperature, an ambient pressure, and an oil temperature.

6. The system as is claim 1, wherein the power source is a pneumatic or electric power source from:

an auxiliary power unit of the aircraft, a ground cart, a cross engine supply, or a stored energy system.

7. The system as in claim 1, wherein the controller is further operable to coordinate control based on one or more of:

an engine speed, a starter speed, a starter valve position, a starter air pressure, a starter system electric current, a rate of speed change, a rate of starter valve position change, a rate of starter air pressure change, and a rate of starter system electric current change.

8. The system as in claim 1, wherein the controller is further operable to coordinate control by commanding one or more adjustment to a baseline dry motoring profile to shift timing of use of the compressed air on an engine basis.

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

a compressed air source operable to supply compressed air;

a first engine system comprising a first gas turbine engine, a first air turbine starter, a first starter air valve, and a first controller operable to command the first starter air valve to control delivery of the compressed air to the first air turbine starter during motoring of the first gas turbine engine;

a second engine system comprising a second gas turbine engine, a second air turbine starter, a second starter air valve, and a second controller operable to command the second starter air valve to control delivery of the compressed air to the second air turbine starter during motoring of the second gas turbine engine; and

at least one engine control interface operable to coordinate control of the first starter air valve through the first controller and the second starter air valve through the second controller to alternate use of the compressed air between the first air turbine starter and the second air turbine starter while maintaining a starting spool speed of the first gas turbine engine and the second gas turbine engine below a resonance speed during motoring.

10. The system of claim 9, wherein the at least one engine control interface coordinates control by commanding intermittent acceleration and deceleration of the starting spool of the first gas turbine engine and the second gas turbine engine in an alternating sequence during motoring.

11. The system of claim 9, wherein timing of coordinated control is determined based on a plurality of performance parameters that are based on one or more of:

an ambient condition, performance limitations of the compressed air source and the first and second air turbine starters driven by the compressed air source, engine drag, and parasitic factors.

12. The system of claim 11, wherein the performance parameters are determined based on one or more of:

an ambient air temperature, an ambient pressure, and an oil temperature.

13. The system of claim 9, wherein the at least one engine control interface is further operable to coordinate control based on one or more of:

an engine speed, a starter speed, a starter valve position, a starter air pressure, a rate of speed change, a rate of starter valve position change, and a rate of starter air pressure change.

14. The system of claim 9, wherein the at least one engine control interface is further operable to coordinate control by commanding one or more adjustment to a baseline dry motoring profile to shift timing of use of the compressed air on an engine basis.

15. A method for alternating starter use during multi-engine motoring in an aircraft, the method comprising:

commanding, by a first controller, a first starter air valve of a first gas turbine engine to open while a second starter air valve of a second gas turbine engine is closed during motoring;

commanding, by the first controller, the first starter air valve to at least partially close based on a starting spool of the first gas turbine engine reaching a first speed threshold;

commanding, by a second controller, the second starter air valve to open after the first starter air valve is at least partially closed;

commanding, by the second controller, the second starter air valve to at least partially close based on the starting spool of the second gas turbine engine reaching a second speed threshold; and

repeating alternating opening and closing of the first starter air valve and the second starter air valve until a motoring termination condition is met.

16. The method as in claim 15, wherein at least one engine control interface coordinates command sequencing of the first controller and the second controller to perform intermittent acceleration and deceleration of the starting spool of the first gas turbine engine and the second gas turbine engine in an alternating sequence during motoring.

17. The method as in claim 15, wherein timing of coordinated control between the first controller and the second controller is determined based on a plurality of performance parameters that are based on one or more of:

an ambient condition, performance limitations of a compressed air source and first and second air turbine starters driven by the compressed air source in response to the first and second starter air valves, engine drag, and parasitic factors.

18. The method as in claim 17, wherein the performance parameters are determined based on one or more of:

an ambient air temperature, an ambient pressure, and an oil temperature.

19. The method as in claim 15, wherein the opening and closing comprises partially opening and partially closing the first and second air valves.

20. The method as in claim 15, wherein the first speed threshold and the second speed threshold are dynamically configurable and below a resonance speed of the starting spool speed of the first gas turbine engine and the second gas turbine engine.