FUEL ATOMIZATION DUAL ORIFICE FUEL NOZZLE

• US 20120151930A1
• Filed: 12/17/2010
• Published: 06/21/2012
• Est. Priority Date: 12/17/2010
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Patel, Nayan Vinodbhai, Benjamin, Michael Anthony, Thomsen, Duane Douglas, Mancini, Alfred Albert
• Granted Patent: US 8,726,668 B2
• Time in Patent Office: Days
• US Class Current: 60/746
• CPC Class Codes: F23D 11/383 with swirl means
• CPC Class Codes: F23D 11/386 Nozzle cleaning
• CPC Class Codes: F23R 2900/00004 Preventing formation of deposits on surfaces of gas turbine components, e.g. coke deposits
• CPC Class Codes: F23R 2900/03042 Film cooled combustion chamber walls or domes
• CPC Class Codes: F23R 2900/03044 Impingement cooled combustion chamber walls or subassemblies
• CPC Class Codes: F23R 3/283 Attaching or cooling of fuel injecting means including supports for fuel injectors, stems, or lances
• CPC Class Codes: F23R 3/286 having fuel-air premixing devices F23R3/30 takes precedence
• CPC Class Codes: F23R 3/36 Supply of different fuels
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

A pilot fuel injector tip includes concentric primary and secondary pilot fuel nozzles having a circular primary exit axially aft and downstream of an annular secondary exit respectively. A fuel nozzle assembly includes a pilot swirler flowpath section having an annular inwardly tapering conical flowpath section surrounding primary and secondary exits. An inwardly tapering conical wall section radially inwardly bounding flowpath section defines a conical surface. Exits are located at or axially forward or upstream of the conical surface. An annular secondary fuel supply passage in secondary pilot fuel nozzle includes a secondary fuel swirler with an array of helical spin slots that may have rectangular cross sections. A chamfered leading edge of an annular wall section disposed between an outer pilot swirler and an inlet to an injector cooling flowpath surrounding the second pilot swirler includes a radially inwardly facing conical chamfered surface for deflecting dirt from cooling flowpath.

Claims

1. A pilot fuel injector tip comprising:

substantially concentric primary and secondary pilot fuel nozzles centered about a centerline axis of the pilot fuel injector tip,

the primary and secondary pilot fuel nozzles having circular primary and annular secondary exits respectively, and

the circular primary exit located axially aft and downstream of the annular secondary exit.

2. A pilot fuel injector tip as claimed in claim 1, further comprising:

an annular secondary fuel supply passage operable for flowing fuel to the annular secondary exit in the secondary pilot fuel nozzle,

an annular secondary fuel swirler in the secondary fuel supply passage, and

the secondary fuel swirler including an annular array of helical spin slots.

3. A pilot fuel injector tip as claimed in claim 2, further comprising the helical spin slots having rectangular cross sections.

4. A gas turbine engine fuel nozzle assembly comprising:

a pilot fuel injector tip substantially centered about a centerline axis in an annular pilot inlet to a pilot mixer,

substantially concentric primary and secondary pilot fuel nozzles in the pilot fuel injector tip,

the primary and secondary pilot fuel nozzles having circular primary and annular secondary exits respectively, and

the circular primary exit located axially aft and downstream of the annular secondary exit.

5. A fuel nozzle assembly as claimed in claim 4, further comprising:

an annular secondary fuel supply passage operable for flowing fuel to the annular secondary exit in the secondary pilot fuel nozzle,

an annular secondary fuel swirler in the secondary fuel supply passage, and

the secondary fuel swirler including an annular array of helical spin slots.

6. A fuel nozzle assembly as claimed in claim 5, further comprising the helical spin slots having rectangular cross sections.

7. A fuel nozzle assembly as claimed in claim 4, further comprising:

an annular inwardly tapering conical flowpath section of a pilot swirler flowpath section,

a first downstream end of the primary pilot fuel nozzle including the circular primary exit,

a second downstream end of the secondary pilot fuel nozzle including the annular secondary exit,

the annular inwardly tapering conical flowpath section surrounding the first and second downstream ends,

an inwardly tapering conical wall section radially inwardly bounding the annular inwardly tapering conical flowpath section and defining a conical surface, and

the circular primary and annular secondary exits located at or axially forward or upstream of the conical surface.

8. A fuel nozzle assembly as claimed in claim 7, further comprising:

an annular secondary fuel supply passage operable for flowing fuel to the annular secondary exit in the secondary pilot fuel nozzle,

an annular secondary fuel swirler in the secondary fuel supply passage, and

the secondary fuel swirler including an annular array of helical spin slots.

9. A fuel nozzle assembly as claimed in claim 8, further comprising the helical spin slots having rectangular cross sections.

10. A fuel injector as claimed in claim 4, further comprising:

an inner pilot swirler located radially outwardly of and adjacent to the dual orifice pilot fuel injector tip,

an outer pilot swirler located radially outwardly of the inner swirler,

a splitter radially positioned between the first and second pilot swirlers,

the inner pilot swirler including a generally cylindrical inner pilot swirler flowpath section upstream and axially forward of an annular inwardly tapering conical flowpath section between the splitter and a radially outer wall of the pilot fuel injector tip,

an inwardly tapering conical wall section of the radially outer wall radially inwardly bounding the inwardly tapering conical flowpath section,

a conical surface defined by the inwardly tapering conical wall section, and

the circular primary and annular secondary exits located at or axially forward or upstream of the conical surface.

11. A fuel nozzle assembly as claimed in claim 10, further comprising:

an annular secondary fuel supply passage operable for flowing fuel to the annular secondary exit in the secondary pilot fuel nozzle,

an annular secondary fuel swirler in the secondary fuel supply passage, and

the secondary fuel swirler including an annular array of helical spin slots.

12. A fuel nozzle assembly as claimed in claim 11, further comprising the helical spin slots having rectangular cross sections.

13. A fuel nozzle assembly as claimed in claim 4, further comprising:

an inner pilot swirler located radially outwardly of and adjacent to the dual orifice pilot fuel injector tip,

an outer pilot swirler located radially outwardly of the inner swirler,

an axially aft or downstream extending injector cooling flowpath disposed radially outwardly of and surrounding the second pilot swirler,

an annular wall section radially disposed between the outer pilot swirler and an annular cooling flowpath inlet to the injector cooling flowpath,

an annular chamfered leading edge of the annular wall section, and

a radially inwardly facing conical chamfered surface of the chamfered leading edge.

14. A fuel injector as claimed in claim 13, further comprising:

a splitter radially positioned between the first and second pilot swirlers,

the inner pilot swirler including a generally cylindrical inner pilot swirler flowpath section upstream and axially forward of an annular inwardly tapering conical flowpath section between the splitter and a radially outer wall of the pilot fuel injector tip,

an inwardly tapering conical wall section of the radially outer wall radially inwardly bounding the inwardly tapering conical flowpath section,

a conical surface defined by the inwardly tapering conical wall section, and

the circular primary and annular secondary exits located at or axially forward or upstream of the conical surface.

15. A fuel nozzle assembly as claimed in claim 14, further comprising:

an annular secondary fuel supply passage operable for flowing fuel to the annular secondary exit in the secondary pilot fuel nozzle,

an annular secondary fuel swirler in the secondary fuel supply passage, and

the secondary fuel swirler including an annular array of helical spin slots.

16. A fuel nozzle assembly as claimed in claim 4, further comprising:

a pilot housing including a centerbody radially surrounding the pilot mixer,

an axially or downstream extending injector cooling flowpath disposed in the pilot housing and radially between a fuel nozzle inner casing and the centerbody,

an upstream forward end of the centerbody including an annular chamfered leading edge of the forward end, and

a radially inwardly facing conical chamfered surface of the chamfered leading edge.

17. A fuel nozzle assembly as claimed in claim 16, further comprising:

a first pilot swirler located radially outwardly of and adjacent to the dual orifice pilot fuel injector tip,

a second pilot swirler located radially outwardly of the first swirler, and

a splitter radially positioned between the first and second pilot swirlers.

18. A fuel nozzle assembly as claimed in claim 17, further comprising a main fuel nozzle located radially outwardly of the primary and secondary pilot fuel nozzles and supported at least in part by the fuel nozzle inner casing.

19. A fuel nozzle assembly as claimed in claim 18, further comprising:

an annular secondary fuel supply passage operable for flowing fuel to the annular secondary exit in the secondary pilot fuel nozzle,

an annular secondary fuel swirler in the secondary fuel supply passage, and

the secondary fuel swirler including an annular array of helical spin slots.

20. A fuel nozzle assembly as claimed in claim 19, further comprising the helical spin slots having rectangular cross sections.