Method and system for operating an engine

Patent metadata

Field	Value
Publication number	US-11713723-B2
Application number	US-201916425488-A
Country	US
Kind code	B2
Filing date	May 29, 2019
Priority date	May 15, 2019
Publication date	Aug 1, 2023
Grant date	Aug 1, 2023

Abstract

Systems and methods for operating an engine are described herein. The engine is operated at low power by supplying fuel to a combustor through a first set of fuel nozzles of at least one first manifold and without supplying fuel to the combustor through a second set of fuel nozzles of at least one second manifold. An amount of fuel to at least in part fill the at least one second manifold to impede fuel coking of the second set of fuel nozzles is determined. The amount of fuel is periodically supplied to the at least one second manifold.

First claim

What is claimed is:

1. A method for operating an engine, the method comprising:
operating the engine at a first power, wherein a fuel is supplied to a combustor of the engine via at least one first manifold of the engine to a first set of nozzles and at least one second manifold of the engine to a second set of nozzles;
operating the engine at a second power that is lower than the first power;
while the engine is at the second power, supplying the fuel to the combustor of the engine through the first set of fuel nozzles of the at least one first manifold of the engine without supplying the fuel to the combustor through the second set of fuel nozzles of the at least one second manifold of the engine; and
while the engine is at the second power, supplying an amount of the fuel at a constant interval to the at least one second manifold to deliver the fuel to the combustor of the engine.

2. The method of claim 1 , further comprising determining the amount of fuel to at least in part fill the at least one second manifold to impede fuel coking of the second set of fuel nozzles.

3. The method of claim 2 , further comprising:
determining an amount of time for one or more components of the engine to overheat when the engine operates at the second power; and
setting a time interval for supplying the amount of fuel to the at least one second manifold at less than the amount of time as determined.

4. The method of claim 2 , further comprising determining a duration for supplying the amount of fuel to the at least one second manifold, the duration determined to fill the at least one second manifold.

5. The method of claim 2 , wherein the engine is decoupled from a rotor of a rotorcraft while the engine is operating at the second power, and the amount of fuel is determined to prevent the engine from being recoupled to the rotor.

6. The method of claim 2 , further comprising determining a rate for supplying the amount of fuel to the at least one second manifold to prevent the engine from surging.

7. The method of claim 2 , wherein one of:
supplying the amount of fuel to the at least one second manifold comprises increasing a fuel pressure above a cracking pressure of a hydraulic flow divider valve, the hydraulic flow divider valve operatively connected to the at least one first manifold and the at least one second manifold, the hydraulic flow divider valve diverting the amount of fuel to the at least one second manifold; and
supplying the amount of fuel to the at least one second manifold comprises actuating a solenoid of a solenoid actuated flow divider valve, the solenoid actuated flow divider valve operatively connected to the at least one first manifold and the at least one second manifold, the solenoid when actuated causing the solenoid actuated flow divider valve to divert the amount of fuel to the at least one second manifold.

8. The method of claim 2 , wherein the supplying the amount of fuel is performed at a set time interval and for a set duration.

9. A system for operating an engine, the system comprising:
at least one processing unit; and
at least one non-transitory computer-readable memory having stored thereon program instructions executable by the at least one processing unit for:
operating the engine at a first power, wherein a fuel is supplied to a combustor of the engine via at least one first manifold of the engine to a first set of nozzles and at least one second manifold of the engine to a second set of nozzles;
operating the engine at a second power that is lower than the first power;
while the engine is at the second power, supplying the fuel to the combustor of the engine through the first set of fuel nozzles of the at least one first manifold of the engine without supplying the fuel to the combustor through the second set of fuel nozzles of the at least one second manifold of the engine; and
while the engine is at the second power, supplying an amount of the fuel at a constant interval to the at least one second manifold to deliver the fuel to the combustor of the engine.

10. The system of claim 9 , wherein the program instructions are further executable for determining the amount of fuel to at least in part fill the at least one second manifold to impede fuel coking of the second set of fuel nozzles.

11. The system of claim 10 , wherein the program instructions are further executable for:
determining an amount of time for one or more components of the engine to overheat when the engine operates at the second power; and
setting a time interval for supplying the amount of fuel to the at least one second manifold at less than the amount of time as determined.

12. The system of claim 10 , wherein the program instructions are further executable for determining a duration for supplying the amount of fuel to the at least one second manifold, the duration determined to fill the at least one second manifold.

13. The system of claim 10 , wherein the engine is decoupled from a rotor of a rotorcraft while the engine is operating at the second power, and the amount of fuel is determined to prevent the engine from being recoupled to the rotor.

14. The system of claim 10 , wherein the program instructions are further executable for determining a rate for supplying the amount of fuel to the at least one second manifold to prevent the engine from surging.

15. The system of claim 10 , wherein one of:
the program instructions executable for supplying the amount of fuel to the at least one second manifold comprise program instructions executable for increasing fuel pressure above a cracking pressure of a hydraulic flow divider valve, the hydraulic flow divider valve operatively connected to the at least one first manifold and the at least one second manifold, the hydraulic flow divider valve diverting the amount of fuel to the at least one second manifold; and
the program instructions executable for supplying the amount of fuel to the at least one second manifold comprise program instructions executable for actuating a solenoid of a solenoid actuated flow divider valve, the solenoid actuated flow divider valve operatively connected to the at least one first manifold and the at least one second manifold, the solenoid when actuated causing the solenoid actuated flow divider valve to divert the amount of fuel to the at least one second manifold.

16. The system of claim 10 , wherein the program instructions are further executable for supplying of the amount of fuel at a set time interval and for a set duration.

17. A computer readable medium having stored thereon program code executable by a processor for operating an engine, the program code comprising instructions for:
operating the engine at a first power, wherein a fuel is supplied to a combustor of the engine via at least one first manifold of the engine to a first set of nozzles and at least one second manifold of the engine to a second set of nozzles;
operating the engine at a second power that is lower than the first power;
while the engine is at the second power, supplying the fuel to the combustor of the engine through the first set of fuel nozzles of the at least one first manifold of the engine without supplying the fuel to the combustor through the second set of fuel nozzles of the at least one second manifold of the engine; and
while the engine is at the second power, supplying an amount of the fuel at a constant interval to the at least one second manifold to deliver the fuel to the combustor of the engine.

18. The computer readable medium of claim 17 , further comprising instructio

Assignees

• Pratt & Whitney Canada

Inventors

• Jarvo James
• Manoukian Patrick
• Beauchesne-Martel Philippe

Classifications

• F02C9/28 Primary

  Regulating systems responsive to plant or ambient parameters, e.g. temperature, pressure, rotor speed (F02C9/30 - F02C9/38, F02C9/44 take precedence) · CPC title

• F02C7/222

  Fuel flow conduits, e.g. manifolds · CPC title

• F05D2220/32

  in gas turbines · CPC title

• F05D2270/3032

  excessive temperatures, e.g. caused by overheating · CPC title

• F02C7/232 Primary

  Fuel valves {(control of fuel supply by means of fuel metering valves F02C9/263)}; Draining valves or systems (valves in general F16K) · CPC title