Combustor system for high fuel/air ratio and reduced combustion dynamics

Patent metadata

Field	Value
Publication number	US-11480338-B2
Application number	US-201715684066-A
Country	US
Kind code	B2
Filing date	Aug 23, 2017
Priority date	Aug 23, 2017
Publication date	Oct 25, 2022
Grant date	Oct 25, 2022

Abstract

Combustor systems are provided. For example, a combustor system comprises a combustor having forward and aft ends and including annular inner and outer liners that each extend generally along an axial direction and define a combustion chamber therebetween. The combustor system also comprises a fuel nozzle having an outlet defined in an outlet end of the fuel nozzle and including a pilot swirler. The outlet is positioned at the forward end of the combustor to direct a fuel-air mixture into the combustion chamber. The combustor system further comprises a main mixer attached to the outlet end of the fuel nozzle and extending about the outlet. A total combustor airflow through the combustor comprises a pilot swirler airflow that is greater than about 14% of the total combustor airflow and a main mixer airflow that is less than about 50% of the total combustor airflow.

First claim

What is claimed is:

1. A combustor system, comprising:
a combustor having a forward end and an aft end, the combustor including an annular inner liner extending along an axial direction and an annular outer liner extending along the axial direction, the annular inner liner and the annular outer liner defining a combustion chamber therebetween;
a fuel nozzle having an outlet defined in an outlet end of the fuel nozzle; and
a main mixer,
wherein the outlet is positioned at the forward end of the combustor to direct a fuel-air mixture into the combustion chamber,
wherein the fuel nozzle includes a pilot swirler,
wherein the fuel nozzle further comprises a main fuel injector and a pilot fuel injector,
wherein an outer boundary wall surrounds the pilot fuel injector,
wherein the main mixer is positioned at the outlet end of the fuel nozzle,
wherein the main mixer extends about the outlet,
wherein the main mixer comprises a plurality of inlet apertures configured to provide a main mixer airflow to a main flow passage,
wherein the main flow passage is defined downstream of the plurality of inlet apertures and in fluid communication with the main fuel injector,
wherein the pilot swirler comprises a pilot air inlet and at least a portion of a pilot flow passage each defined between the outer boundary wall and the pilot fuel injector,
wherein a pilot splitter is positioned in the pilot flow passage,
wherein a downstream end of the pilot splitter surrounds the pilot fuel injector,
wherein the pilot air inlet and the pilot flow passage each comprise a radial height upstream of the pilot splitter,
wherein the pilot swirler is configured to provide a pilot swirler airflow to the pilot flow passage, and
wherein a radial height of the portion of the pilot flow passage defined between the outer boundary wall and the pilot fuel injector is greater than a radial height of the main flow passage.

2. The combustor system of claim 1 , wherein the annular inner liner is formed from a ceramic matrix composite (CMC) material.

3. The combustor system of claim 1 , wherein the annular outer liner is formed from a ceramic matrix composite (CMC) material.

4. The combustor system of claim 1 , wherein the fuel nozzle is configured to provide between 0% and 70% of the fuel flow to the main fuel injector at the high power operating condition.

5. The combustor system of claim 4 , wherein the fuel nozzle is configured to provide between 30% to 100% of the fuel flow to the pilot fuel injector at the high power operating condition.

6. The combustor system of claim 1 , further comprising:
a combustor dome extending along a radial direction between the annular inner liner and the annular outer liner, the fuel nozzle disposed through the combustor dome.

7. The combustor system of claim 1 ,
wherein the pilot flow passage comprises a flow passage area normal to a direction of the pilot swirler airflow therethrough;
wherein a total combustor airflow through the combustor comprises the pilot swirler airflow proportional to at least the main mixer airflow,
wherein the total combustor airflow is split between at least the pilot swirler airflow comprising at least 21% of the total combustor airflow through the combustor and the main mixer airflow comprising between 25% and 40% of the total combustor airflow through the combustor,
wherein the flow passage area and the radial height of the pilot swirler together correspond to the pilot swirler airflow of at least 21% of the total combustor airflow, and
wherein the main mixer airflow through the main flow passage at least between a main mixer wall radially spaced apart from a fuel nozzle outer wall corresponds to the main mixer airflow.

8. The combustor system of claim 7 ,
wherein the radial height of the pilot flow passage corresponds to the pilot swirler airflow between 21% to 40% of the total combustor airflow to the combustor, and wherein the radial height of the pilot flow passage corresponds to the pilot swirler airflow proportional to the radial spacing of the main flow passage between the main mixer wall and the fuel nozzle outer wall through which main mixer airflow is provided to the combustor.

9. The combustor system of claim 1 ,
wherein a pilot inner air passage is defined between the pilot fuel injector and the pilot splitter, and
wherein a radial height of the pilot inner air passage is greater than the radial height of the main flow passage.

10. A combustor system for a gas turbine engine, comprising:
a combustor having a forward end and an aft end, the combustor including:
an annular inner liner extending along an axial direction, the annular inner liner formed from a ceramic matrix composite (CMC) material, and
an annular outer liner extending along the axial direction, the annular outer liner formed from a CMC material, the annular inner liner and the annular outer liner defining a combustion chamber therebetween;

a fuel nozzle assembly; and
a main mixer,
wherein the fuel nozzle assembly includes a fuel nozzle having an outlet defined in an outlet end of the fuel nozzle,
wherein the outlet is positioned at the forward end of the combustor to direct a fuel-air mixture into the combustion chamber,
wherein the fuel nozzle includes a pilot swirler,
wherein the fuel nozzle comprises a main fuel injector and a pilot fuel injector,
wherein each of the main fuel injector and the pilot fuel injector is configured to receive a portion of a fuel flow to the fuel nozzle,
wherein an outer boundary wall surrounds the pilot fuel injector,
wherein the main mixer is positioned at the outlet end of the fuel nozzle,
wherein the main mixer extends about the outlet,
wherein the main mixer comprises a plurality of inlet apertures configured to provide a main mixer airflow to a main flow passage,
wherein the main flow passage is defined downstream of the plurality of inlet apertures and in fluid communication with the main fuel injector,
wherein the pilot swirler comprises a pilot air inlet and at least a portion of a pilot flow passage each defined between the outer boundary wall and the pilot fuel injector,
wherein a pilot splitter is positioned in the pilot flow passage,
wherein a downstream end of the pilot splitter surrounds the pilot fuel injector,
wherein the pilot air inlet and the pilot flow passage each comprise a radial height upstream of the pilot splitter,
wherein the pilot swirler is configured to provide a pilot swirler airflow to the pilot flow passage, and
wherein a radial height of the portion of the pilot flow passage defined between the outer boundary wall and the pilot fuel injector is greater than a radial height of the main flow passage.

11. The combustor system of claim 10 , wherein the fuel nozzle is configured to provide between 0% and 70% of the fuel flow to the main fuel injector at the high power operating condition.

12. The combustor system of claim 11 , wherein the fuel nozzle is configured to provide between 30% to 100% of the fuel flow to the pilot fuel injector at the high power operating condition.

13. The combustor system of claim 10 , further comprising:
a combustor dome extending along a radial direction between the annular inner liner and the annular outer liner, the fuel nozzle disposed through the combustor dome.

14. The combustor system of claim 13 , wherein the combustor dome is formed from a CMC material.

15. The combustor system of claim 10 ,
wherein the radial height of the pilot swirler corresponds to at least 21% of a total combustor airflow to the combustor, and
wherein the main mixer airflow through

Assignees

• Gen Electric

Inventors

• Stevens Eric John
• Durbin Mark David
• Burrus David Louis

Classifications

• F23R3/286 Primary

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

• F23R3/50

  Combustion chambers comprising an annular flame tube within an annular casing (toroidal combustion chambers F23R3/52) · CPC title

• 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

• F23R2900/00014

  Reducing thermo-acoustic vibrations by passive means, e.g. by Helmholtz resonators · CPC title

• F23R3/58

  Cyclone or vortex type combustion chambers · CPC title