Diffusion nozzles for low-oxygen fuel nozzle assembly and method

Patent metadata

Field	Value
Publication number	US-8955329-B2
Application number	US-201113278960-A
Country	US
Kind code	B2
Filing date	Oct 21, 2011
Priority date	Oct 21, 2011
Publication date	Feb 17, 2015
Grant date	Feb 17, 2015

Abstract

A fuel nozzle assembly has been conceived for a combustor in a gas turbine including a first passage and fourth passage connectable to a source of gaseous fuel, a second passage connectable to a source of a gaseous oxidizer, and a third passage coupled to a source of a diluent gas, wherein the first passage is a center passage and is configured to discharge gaseous fuel from nozzles at a discharge end of the center passage, the second passage is configured to discharge the gaseous oxidizer through nozzles adjacent to the nozzles for the center passage, the third passage discharges a diluent gas through nozzles adjacent to the nozzles for the second passage, and the fourth passage is configured to discharges the gaseous fuel downstream of the discharge location for the first, second and third passages.

First claim

What is claimed is:

1. A fuel nozzle assembly for a combustor in a gas turbine comprising:
a first passage and a fourth passage each connectable to a source of gaseous fuel, a second passage connectable to a source of a gaseous oxidizer and a third passage coupled to a source of a diluent gas;
wherein the first passage is a center passage and is configured to discharge the gaseous fuel from nozzles at a discharge end of the center passage wherein the discharge end is within a cavity of the fuel nozzle assembly, the second passage is configured to discharge the gaseous oxidizer through nozzles adjacent to the nozzles for the center passage and within the cavity, the third passage is configured to discharge a diluent gas through nozzles adjacent to the nozzles for the second passage and within the cavity, and the fourth passage is configured to discharge the gaseous fuel downstream of an open end of the cavity.

2. The fuel nozzle assembly as in claim 1 wherein the second, third and fourth passages are coaxial to an axis of the center passage, the nozzles for the third passage form an annular array around the axis, the nozzles for the second passage form an annular array around the axis and between the annular array for the third passage and the nozzles for the center passage, and the fourth passage is configured to discharge the gaseous fuel through nozzles which form an annular array around the open end of the cavity.

3. The fuel nozzle assembly as in claim 1 a discharge end of the fourth passage is aligned axially with a downstream end of the fuel nozzle assembly.

4. The fuel nozzle assembly as in claim 1 wherein the nozzles for the first passage comprise narrow passages each having a radially outwardly oriented pitch angle and a positive yaw angle in a range of 40 to 60 degrees, and wherein the nozzle of the second and third passages each having a radially inwardly oriented pitch angle and a yaw angle of 5 to 16 degrees, wherein the yaw angle for the nozzles of the third passage is positive and the yaw angle for the nozzles of the second passage is negative.

5. The fuel nozzle assembly as in claim 1 wherein the source of the diluent gas is a compressor for the gas turbine and the diluent gas includes a working fluid flowing through the gas turbine.

6. The fuel nozzle assembly as in claim 1 wherein the source of the oxidizer gas is the atmosphere and the oxidizer gas includes atmospheric air.

7. A combustor for a gas turbine having a reduced oxygen working fluid, wherein the combustor comprises:
a combustion chamber having a downstream end through which combustion gases flow towards a turbine of the gas turbine, and an inlet end opposite to the downstream end;
fuel nozzle assembly, at the upstream end of the combustor, which includes a center passage and fourth passage connectable to a source of gaseous fuel, a second passage connectable to a source of a gaseous oxidizer and a third passage coupled to a source of a diluent gas, wherein the center passage is configured to discharge the gaseous fuel from nozzles at a discharge end of the center passage and into a cavity within the fuel nozzle assembly, the second passage is configured to discharge the gaseous oxidizer into the cavity through nozzles adjacent to the nozzles for the center passage, the third passage is configured to discharge a diluent gas into the cavity through nozzles adjacent to the nozzles for the second passage and the fourth passage is configured to discharge the gaseous fuel downstream of the cavity.

8. The combustor fuel nozzle assembly as in claim 7 wherein the second, third and fourth passages are coaxial to an axis of the center passage, the nozzles for the third passage form an annular array around the axis, the nozzles for the second passage form an annular array around the axis and between the annular array for the third passage and the nozzles for the center passage, and the fourth passage is configured to discharge the gaseous fuel through nozzles arranged as an annular array around a downstream open end of the cavity.

9. The combustor as in claim 7 wherein a discharge end of the fourth passage is aligned axially with a downstream of the fuel nozzle assembly.

10. The combustor as in claim 7 wherein the nozzles for the first passage comprise narrow passages each having a radially outwardly oriented pitch angle and a positive yaw angle in a range of 40 to 60 degrees, and wherein the nozzle of the second and third passages each a radially inwardly oriented pitch angle and a yaw angle of 5 to 16 degrees, wherein the yaw angle for the nozzles of the third passage is positive and the yaw angle for the nozzles of the second passage is negative.

11. The combustor as in claim 7 wherein the source of the diluent gas is a compressor for the gas turbine and the diluent gas includes a working fluid flowing through the gas turbine.

12. The combustor as in claim 7 wherein the source of the oxidizer gas is the atmosphere and the oxidizer gas includes atmospheric air.

13. A method to produce combustion gases in a combustor for a low oxygen gas turbine comprising, wherein the combustor includes a fuel nozzle assembly and a combustion chamber, the method includes:
discharging a fuel from a center passage and from a fourth passage each extending through the fuel nozzle assembly, wherein the fuel is discharged from the center passage and into a cavity at the end of the fuel nozzle assembly as a swirling flow rotating in a first rotational direction;
discharging an oxidizer into the chamber from a second passage adjacent the center passage, wherein a discharge end of the second passage is adjacent a discharge end of the center passage, and wherein the oxidizer is discharged into the cavity as a swirling flow rotating in a second rotational direction which is opposite to the first rotational direction;
discharging a diluent from a third passage adjacent the second passage, wherein a discharge end of the third passage is adjacent the discharge end of the second passage, and wherein the diluent is discharged into the cavity as a swirling flow rotating in the first rotational direction;
retarding combustion of the fuel and oxidizer by the discharge of the diluent into the cavity;
discharging the fuel from a discharge end of the fourth passage adjacent a downstream, open end of the cavity, and
initiating combustion of the fuel and oxidizer in the combustion chamber and downstream of the open end of the cavity.

14. The method of claim 13 wherein the fuel is discharged from nozzles in the discharge end of the fourth passage which extend around the open end of the cavity.

15. The method of claim 13 wherein the diluent is compressed working fluid from the gas turbine and discharged by a compressor of the gas turbine, wherein the working fluid includes exhaust gases from the gas turbine when discharged by the compressor.

16. The method of claim 13 wherein the second and third passages are coaxial to an axis of the center passage, and the oxidizer and diluent are each discharged in separate conical swirling flows extending radially inward towards the fuel being discharged by the center passage.

17. The method of claim 13 wherein the oxidizer and diluent are discharged from second and third passages, respectively, at yaw angles in a range of 5 to 16 degrees to induce the swirling flows.

18. The method of claim 13 wherein the source of the oxidizer gas is the atmosphere and the oxidizer gas includes the atmospheric air.

Assignees

• Popovic Predrag
• Baruah Abinash
• Gen Electric

Inventors

• Popovic Predrag
• Baruah Abinash

Classifications

• F23D14/24 Primary

  at least one of the fluids being submitted to a swirling motion · CPC title

• F23R3/28

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