System and method for purging a fuel manifold of a gas turbine engine using a pump

Patent metadata

Field	Value
Publication number	US-11486303-B2
Application number	US-202016871127-A
Country	US
Kind code	B2
Filing date	May 11, 2020
Priority date	May 15, 2019
Publication date	Nov 1, 2022
Grant date	Nov 1, 2022

Abstract

Methods and systems of operating a gas turbine engine in a low-power condition are provided. In one embodiment, the method includes supplying fuel to a combustor by supplying fuel to a first fuel manifolds and a second fuel manifold of the gas turbine engine. The method also includes, while supplying fuel to the combustor by supplying fuel to the first fuel manifold: stopping supplying fuel to the second fuel manifold; and using a pump to drive gas into the second fuel manifold to flush fuel in the second fuel manifold into the combustor and hinder coking in the second fuel manifold and associated fuel nozzles.

First claim

What is claimed is:

1. A method of operating a gas turbine engine, the gas turbine engine having a first fuel manifold and a second fuel manifold configured to supply fuel to a combustor of the gas turbine engine, the method comprising:
supplying air from a compressor section of the gas turbine engine to the combustor;
supplying fuel to the combustor by supplying fuel to the first and second fuel manifolds;
while supplying fuel to the combustor by supplying fuel to the first fuel manifold:
stopping supplying fuel to the second fuel manifold; and
using a pump other than the compressor section of the gas turbine engine to drive gas into the second fuel manifold to flush fuel in the second fuel manifold into the combustor.

2. The method of claim 1 , comprising using a flow divider valve to stop supplying fuel to the second fuel manifold and to supply fuel to the first fuel manifold.

3. The method of claim 1 , wherein the gas turbine engine is mounted to an aircraft and the method is executed during flight of the aircraft.

4. The method of claim 3 , wherein:
the aircraft is a rotary wing aircraft;
the gas turbine engine is a first gas turbine engine;
a second gas turbine engine is mounted to the aircraft; and
the method includes:
operating the first gas turbine engine in a low-power mode of operation while fuel is supplied to the first fuel manifold and fuel supply to the second fuel manifold is stopped; and
operating the second gas turbine engine in a high-power mode of operation while the first gas turbine engine is operated in the low-power mode of operation.

5. The method of claim 1 , comprising, after fuel in the second fuel manifold is flushed into the combustor and while continuing to supply fuel to the combustor by supplying fuel to the first fuel manifold, stopping the using of the pump to drive gas into the second fuel manifold.

6. The method of claim 1 , comprising supplying the gas from the pump to a fuel line at a location between a flow divider valve and the second fuel manifold.

7. The method of claim 1 , comprising, after fuel in the second fuel manifold is flushed into the combustor and while supplying fuel to the second fuel manifold is stopped, continuing to supply fuel to the combustor by supplying fuel to the first fuel manifold.

8. The method of claim 1 , wherein at least a majority of the gas is air.

9. A method of operating a multi-engine system of an aircraft, the multi-engine system including a first gas turbine engine (FGTE) and a second gas turbine engine (SGTE) drivingly connected to a common load, the method comprising:
operating the FGTE and the SGTE to drive the common load, operating the SGTE including supplying fuel to a combustor of the SGTE by supplying fuel to a first fuel manifold and a second fuel manifold of the SGTE;
while operating the FGTE and supplying fuel to the combustor of the SGTE by supplying fuel to the first fuel manifold of the SGTE:
stopping supplying fuel to the second fuel manifold of the SGTE; and
using a pump to drive gas into the second fuel manifold of the SGTE to flush fuel in the second fuel manifold into the combustor of the SGTE.

10. The method of claim 9 , comprising using a flow divider valve to stop supplying fuel to the second fuel manifold and to supply fuel to the first fuel manifold.

11. The method of claim 9 , wherein the common load includes a rotary wing of the aircraft and the method is executed during flight of the aircraft.

12. The method of claim 9 , comprising, after fuel in the second fuel manifold is flushed and while continuing to supply fuel to the combustor of the SGTE by supplying fuel to the first fuel manifold, stopping the using of the pump to drive gas into the second fuel manifold.

13. The method of claim 9 , comprising supplying the gas from the pump to a fuel line at a location between a flow divider valve and the second fuel manifold.

14. The method of claim 9 , comprising, after fuel in the second fuel manifold is flushed and while supplying fuel to the second fuel manifold is stopped, continuing to supply fuel to the combustor of the SGTE by supplying fuel to the first fuel manifold.

15. A gas turbine engine comprising:
a compressor section for pressurizing air;
a combustor in which the pressurized air is mixed with fuel and ignited for generating an annular stream of combustion gases;
a turbine for extracting energy from the combustion gases;
a first fuel manifold configured to supply fuel to the combustor;
a second fuel manifold configured to supply fuel to the combustor;
one or more valves actuatable between a first configuration and a second configuration, the one or more valves configured to supply fuel to the first and second fuel manifolds in the first configuration, the one or more valves configured to supply fuel to the first fuel manifold and stop supplying fuel to the second fuel manifold in the second configuration; and
a pump other than the compressor section and configured to, in the second configuration of the one or more valves, drive gas into the second fuel manifold to flush fuel in the second fuel manifold into the combustor.

16. The gas turbine engine of claim 15 , comprising a fuel line establishing fluid communication between a first of the one or more valves and the second fuel manifold, the pump configured to discharge the gas into the fuel line at a location downstream of the first valve.

17. The gas turbine engine of claim 15 , wherein the pump is electrically driven by an electric motor.

Assignees

• Pratt & Whitney Canada

Inventors

• Shenouda Antwan

Classifications

• F02C9/263

  by means of fuel metering valves · CPC title

• F02C7/222

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

• F02C7/228

  Dividing fuel between various burners · CPC title

• F02C6/02 Primary

  Plural gas-turbine plants having a common power output · 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