Gas turbine engine fuel air mixer

Patent metadata

Field	Value
Publication number	US-9404658-B2
Application number	US-201314105495-A
Country	US
Kind code	B2
Filing date	Dec 13, 2013
Priority date	Mar 5, 2013
Publication date	Aug 2, 2016
Grant date	Aug 2, 2016

Abstract

A gas turbine engine device is disclosed for mixing fuel and air prior to a combustion. The device includes a pilot mixer and a main mixer each having a fuel opening for the delivery of fuel to one or more passages. In one form the main mixer includes an inner passage and an outer passage and in which a fuel opening delivers fuel to the inner passage. The main mixer can include swirlers in the inner and/or outer passages. The pilot mixer can also include a swirler. In one embodiment the main mixer includes a converging flow path and/or a diverging flow path. The pilot mixer can also include a converging and/or diverging flow path and in one form is sheltered from an exit of the device. The main mixer fuel opening can be disposed between an upstream end and a downstream end of the mixer.

First claim

What is claimed is:

1. An apparatus comprising:
a main gas turbine fuel/air mixer having a first main swirler and a main fuel opening for a delivery of fuel to a first main passage, the main fuel opening positioned between an upstream side of the first main swirler and a downstream side of the first main swirler;
a main convergent-divergent portion downstream of the first main swirler, the main convergent-divergent portion configured to provide a space to mix a fuel from the main fuel opening with an air having a movement provided by the first main swirler; and
a pilot mixer having a pilot swirler positioned upstream of a pilot fuel opening for a delivery of a fuel to the pilot mixer, the pilot mixer including a fuel aperture and an annular passage for passage of air that surrounds the fuel aperture, the pilot mixer including a pilot convergent-divergent portion that converges at a narrowest diameter of a throat thereof, wherein the pilot fuel opening through which the fuel exits is downstream of the narrowest diameter, and wherein all the air passing through the pilot mixer passes through the pilot swirler before entering the pilot convergent-divergent portion.

2. The apparatus of claim 1 , wherein the main fuel opening is configured to deliver a jet of fuel transverse to a passing stream of air.

3. The apparatus of claim 2 , wherein the first main passage includes a member positioned opposite the main fuel opening for forming a fuel film on a surface thereof.

4. The apparatus of claim 2 , which further includes a second main passage radially offset from the first main passage, the second main passage including a second main swirler located upstream from the main convergent-divergent portion.

5. The apparatus of claim 1 , which further includes a second main swirler radially outward of the first main swirler, and wherein the main fuel opening is located to provide fuel to the first main swirler, and wherein the pilot fuel opening is recessed from a pilot fuel/air mixture outlet.

6. The apparatus of claim 5 , wherein the first main passage, a second main passage, and the main convergent-divergent portion are part of a main passage, and wherein a portion of an inlet of the main passage is radially outward of a portion of an outlet of the main passage.

7. The apparatus of claim 1 , which further includes a second main passage having a second swirler, and wherein the pilot mixer includes the pilot convergent-divergent portion.

8. An apparatus comprising:
a gas turbine engine fuel module having a main mixer and a pressure swirl pilot mixer, the gas turbine engine fuel module including:
the pressure swirl pilot mixer having a pilot fuel opening structured to deliver fuel to a pilot passage that includes a swirler, the pilot mixer including a fuel aperture and an annular passage for passage of air that surrounds the fuel aperture, the pilot mixer including a pilot convergent-divergent portion that converges at a narrowest diameter of a throat thereof, wherein the pilot fuel opening through which the fuel exits is downstream of the narrowest diameter, and wherein all the air passing through the pilot mixer passes through the swirler before entering the pilot convergent-divergent portion; and
the main mixer having a main flow path that includes a first flow path having a first swirler radially inward from a second flow path having a second swirler and both the first flow path and second flow path merge to a common flow path prior to a main mixer outlet, the main mixer also having a fuel opening positioned in the first flow path and structured to dispense a fuel upstream of the common flow path.

9. The apparatus of claim 8 , which further includes a main mixer flow path downstream of both the first flow path and the second flow path, the main mixer flow path having a convergent section.

10. The apparatus of claim 9 , wherein the convergent section is defined by an outer wall and an inner wall, each of the outer wall and inner wall having a decreasing radial distance from a central axis of the gas turbine engine fuel module along a length of the main mixer flow path.

11. The apparatus of claim 10 , wherein the outer wall and inner wall are configured to provide for a divergent section downstream of the convergent section.

12. The apparatus of claim 8 , wherein the fuel opening is oriented to provide a jet of fuel to the first flow path.

13. The apparatus of claim 8 , wherein the first flow path includes a fuel filming surface to receive a jet of fuel from the fuel opening, and wherein the common flow path includes a convergent divergent section.

14. The apparatus of claim 13 , wherein the pilot fuel opening of the pilot mixer is recessed from an outlet of the pilot mixer.

15. A method comprising:
delivering a pilot fuel to a pilot passage to form a pilot fuel/air mixture, the pilot passage including an annular passage having vanes for swirling a pilot air and including a fuel aperture and an annular passage for passage of air that surrounds the fuel aperture, the pilot mixer including a pilot convergent-divergent portion that converges at a narrowest diameter of a throat thereof, wherein the fuel aperture through which the fuel exits is downstream of the narrowest diameter, and wherein all the air passing through the pilot mixer passes through the vanes before entering the pilot convergent-divergent portion;
providing a main fuel to a first main passage located radially inward of a second main passage, the first main passage having a plurality of members oriented to impart a rotational component to a main air passing through the first main passage, the providing located between an upstream end of one of the plurality of members and a downstream end of the one of the plurality of members and oriented to eject fuel in a direction away from a central axis of the pilot passage;
mixing the main fuel with the main air in the first main passage; and
turning a flow line of the mixture of main fuel and main air toward a pilot mixer in another passage located downstream of the providing the main fuel.

16. The method of claim 15 , which further includes accelerating the mixture of main fuel and air in the another passage, the another passage having a converging flow area.

Assignees

• Rolls Royce Corp

Inventors

• Nickolaus Daniel

Classifications

• F23R3/343

  Pilot flames, i.e. fuel nozzles or injectors using only a very small proportion of the total fuel to insure continuous combustion (ignition in gas-turbine plants F02C7/264; pilot flame igniters F23Q9/00) · CPC title

• F23R3/286 Primary

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

• F23R3/14

  by using swirl vanes · CPC title

• F23R2900/03343

  Pilot burners operating in premixed mode · CPC title