Hybrid air blast fuel nozzle

Patent metadata

Field	Value
Publication number	US-9939157-B2
Application number	US-201514643335-A
Country	US
Kind code	B2
Filing date	Mar 10, 2015
Priority date	Mar 10, 2015
Publication date	Apr 10, 2018
Grant date	Apr 10, 2018

Abstract

A fuel nozzle apparatus for a gas turbine engine includes: a first pilot fuel injector disposed on a centerline axis of the fuel nozzle which defines a direction of air flow through the fuel nozzle, the first pilot fuel injector being of a pressure atomizing type; an annular second pilot fuel injector at least partially surrounding the first pilot fuel injector, the second pilot fuel injector being of an air blast type and having a fuel outlet disposed axially downstream and radially outboard of the first pilot fuel injector; an annular venturi surrounding the first and second pilot fuel injectors, the venturi including a throat of minimum diameter; an array of inner swirl vanes extending between the first pilot fuel injector and the second pilot fuel injector; and an array of outer swirl vanes extending between the second pilot fuel injector and the venturi.

First claim

What is claimed is:

1. A fuel nozzle apparatus for a gas turbine engine, comprising:
a first pilot fuel injector disposed on a centerline axis of the fuel nozzle which defines a direction of air flow through the fuel nozzle, the first pilot fuel injector being a pressure atomizing injector and having a fuel outlet;
an annular second pilot fuel injector at least partially surrounding the first pilot fuel injector, the second pilot fuel injector being an air blast injector and having a fuel outlet disposed axially downstream and radially outboard of the fuel outlet of the first pilot fuel injector, the second pilot fuel injector placed on a diverging wall of a first venturi downstream of the first pilot fuel injector;
an air passage surrounding the first pilot fuel injector and the second pilot fuel injector;
a second venturi surrounding the first pilot fuel injector and the second pilot fuel injector, the second venturi including a throat of minimum diameter and forming the outer wall of the air passage;
an array of inner swirl vanes extending between the first pilot fuel injector and the second pilot fuel injector; and
an array of outer swirl vanes extending between the second pilot fuel injector and the second venturi,
wherein fuel from the first pilot fuel injector mixes with air in the first venturi to form a fuel and air mixture, and
wherein the fuel and air mixture from the first venturi, the fuel from the second pilot fuel injector and the air from the air passage mixes at the throat of the second venturi before exiting the fuel nozzle into a combustor.

2. The apparatus of claim 1 , wherein the second pilot fuel injector includes an annular fuel manifold defined therein which communicates with the fuel outlet of the second pilot fuel injector, and
wherein the fuel in the second pilot fuel injector is atomized by blasting air at the fuel.

3. The apparatus of claim 2 , wherein an annular inner heat shield is disposed radially inboard of the fuel manifold, separated from the fuel manifold by an air space.

4. The apparatus of claim 2 , wherein an annular outer heat shield is disposed radially outboard of the fuel manifold, separated from the fuel manifold by an air space.

5. The apparatus of claim 1 , wherein at least some of the inner swirl vanes of the array of inner swirl vanes have a helical or partially-helical shape.

6. The apparatus of claim 1 , wherein at least some of the outer swirl vanes of the array of outer swirl vanes have a helical or partially-helical shape.

7. A fuel nozzle system comprising:
the apparatus of claim 1 ;
an annular outer body surrounding the first pilot fuel injector and the second pilot fuel injector, the outer body extending parallel to the centerline axis, the outer body having a generally cylindrical exterior surface extending between forward and aft ends, and having a plurality of openings passing through the exterior surface;
an annular main injection ring disposed inside the outer body, the main injection ring including an annular array of main fuel orifices, each main fuel orifice being aligned with one of the openings in the outer body; and
a main fuel gallery extending within the main injection ring in a circumferential direction and communicating with the array of main fuel orifices.

8. The apparatus of claim 1 , wherein the throat of the second venturi is axially downstream of the second pilot fuel injector.

Assignees

• Gen Electric

Inventors

• Patel Nayan Vinodbhai
• Thomsen Duane Douglas

Classifications

• F23D11/24

  by pressurisation of the fuel before a nozzle through which it is sprayed by a substantial pressure reduction into a space · CPC title

• F23R3/286 Primary

  having fuel-air premixing devices (F23R3/30 takes precedence) · CPC title

• F23R3/28 Primary

  characterised by the fuel supply (burners F23D) · CPC title

• F23D2900/00015

  Pilot burners specially adapted for low load or transient conditions, e.g. for increasing stability · CPC title

• F23D2900/11101

  Pulverising gas flow impinging on fuel from pre-filming surface, e.g. lip atomizers · CPC title