AIR SUPPLY CONTROL DURING MOTORING OF A GAS TURBINE ENGINE

• US 20180023479A1
• Filed: 07/21/2016
• Published: 01/25/2018
• Est. Priority Date: 07/21/2016
• Status: Active Application

• Current Assignee: Rtx Corporation
• Original Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Clauson, Jesse W., Gelwan, David
• Application Number:
  US15/216,168
• Publication Number:
  US 20180023479A1
• Time in Patent Office: Days
• CPC Class Codes: B64D 27/12 within, or attached to, wings
• CPC Class Codes: F01D 17/145 by means of valves, e.g. for steam turbines valves in general F16K
• 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: F01D 19/02 dependent on temperature of component parts, e.g. of turbine-casing
• CPC Class Codes: F01D 21/003 Arrangements for testing or measuring for measuring vibrations G01H
• CPC Class Codes: F01D 21/02 Shutting-down responsive to overspeed
• CPC Class Codes: F02C 7/27 Fluid drives turbine starters F02C7/277
• CPC Class Codes: F02C 7/277 the starter being a separate turbine
• CPC Class Codes: F05D 2220/32 in gas turbines
• CPC Class Codes: F05D 2220/50 for auxiliary power units (APU's)
• CPC Class Codes: F05D 2260/85 Starting
• CPC Class Codes: F05D 2270/114 by limiting mechanical stresses

Abstract

A system for motoring a gas turbine engine of an aircraft is provided. The system includes an air turbine starter, a starter air valve operable to deliver compressed air to the air turbine starter, and a controller. The controller is operable to control motoring of the gas turbine engine, detect a fault condition that prevents the controller from maintaining a motoring speed below a threshold level, and command a mitigation action that reduces delivery of the compressed air to the air turbine starter based on detection of the fault condition.

Claims

1. A system for motoring a gas turbine engine of an aircraft, the system comprising:

an air turbine starter;

a starter air valve operable to deliver compressed air to the air turbine starter; and

a controller operable to control motoring of the gas turbine engine, detect a fault condition that prevents the controller from maintaining a motoring speed below a threshold level, and command a mitigation action that reduces delivery of the compressed air to the air turbine starter based on detection of the fault condition.

2. The system as in claim 1, wherein the compressed air is driven by an auxiliary power unit of the aircraft.

3. The system as in claim 2, wherein the controller relays the command for the mitigation action to the auxiliary power unit through an engine control interface using a digital communication bus.

4. The system as in claim 3, wherein the mitigation action comprises opening one or more bleed valves to purge the compressed air.

5. The system as in claim 4, wherein the controller receives state information of the one or more bleed valves through the engine control interface.

6. The system as is claim 1, wherein the mitigation action comprises shutting one or more supply valves of the compressed air.

7. The system as in claim 1, wherein the fault condition comprises a stuck open position of the starter air valve.

8. The system as in claim 1, wherein the fault condition comprises a pressure surge of the compressed air.

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

an auxiliary power unit operable to supply compressed air to the aircraft;

an engine control interface operable to communicate with the auxiliary power unit on a digital communication bus;

an air turbine starter operable to drive rotation of a starting spool of a gas turbine engine of the aircraft in response to the compressed air;

a starter air valve operable to deliver the compressed air to the air turbine starter; and

a controller operable to control motoring of the starting spool by the air turbine starter, detect a fault condition that prevents the controller from maintaining a motoring speed below a threshold level, and send a command to the engine control interface to initiate a mitigation action that reduces delivery of the compressed air to the air turbine starter based on detection of the fault condition.

10. The system of claim 9, wherein the mitigation action comprises opening one or more bleed valves to purge the compressed air.

11. The system of claim 10, wherein the controller receives state information of the one or more bleed valves through the engine control interface.

12. The system of claim 9, wherein the mitigation action comprises shutting one or more supply valves of the compressed air.

13. The system of claim 9, wherein the fault condition comprises a stuck open position of the starter air valve.

14. The system of claim 9, wherein the fault condition comprises a pressure surge of the compressed air.

15. A method for air supply control during motoring of a gas turbine engine, the method comprising:

commanding, by a controller, a starter air valve to control delivery of compressed air to an air turbine starter during motoring of the gas turbine engine;

detecting a fault condition that prevents the controller from maintaining a motoring speed below a threshold level; and

commanding a mitigation action that reduces delivery of the compressed air to the air turbine starter based on detecting the fault condition.

16. The method as in claim 15, wherein the compressed air is driven by an auxiliary power unit of the aircraft and the controller relays a command for the mitigation action to the auxiliary power unit through an engine control interface using a digital communication bus.

17. The method as in claim 16, the mitigation action comprises opening one or more bleed valves to purge the compressed air.

18. The method as in claim 17, further comprising receiving, by the controller, state information of the one or more bleed valves through the engine control interface.

19. The method as in claim 15, wherein the mitigation action comprises shutting one or more supply valves of the compressed air.

20. The method as in claim 15, wherein the fault condition comprises a stuck open position of the starter air valve or a pressure surge of the compressed air.