Gas-only cartridge for a premix fuel nozzle
A gas-only cartridge for a fuel nozzle includes a flange that defines a plurality of apertures for receiving a gaseous fuel, an outer tube that is coupled to the flange and an inner tube that extends axially within the outer tube. The inner tube and the outer tube define a fuel passage therebetween and the fuel passage is in fluid communication with the plurality of apertures of the flange. A fuel distribution tip is disposed at a downstream end of the gas-only cartridge and defines a plurality of fuel ports circumferentially spaced along and annularly arranged about an outer surface of the fuel distribution tip. The fuel ports are in fluid communication with the fuel passage.
1. A fuel nozzle, comprising:
a center body;
a tip body disposed at a downstream end of the center body, the tip body defining an opening that extends axially through the tip body and including a plurality of channels circumferentially spaced and positioned along an inner surface of the tip body within the opening, wherein each channel defines a flow passage through an upstream surface and a downstream surface of the tip body; and
a gas-only cartridge that extends axially within the center body, the gas-only cartridge having an outer tube, an inner tube extending axially within the outer tube and a fuel passage defined therebetween, wherein the outer tube and the centerbody define a secondary premix air passage therebetween, the gas-only cartridge further comprising a fuel distribution tip that extends at least partially through the opening of the tip body, the fuel distribution tip including a plurality of circumferentially spaced fuel ports in fluid communication with the fuel passage, wherein each fuel port is in fluid communication with a respective channel of the tip body and each channel is in fluid communication with the secondary premix air passage.
2. The fuel nozzle as in claim 1 , wherein each channel of the plurality of channels is “U” shaped.
3. The fuel nozzle as in claim 1 , wherein the inner surface of the tip body forms a seal against an outer surface of the fuel distribution tip between each circumferentially adjacent channel of the plurality of channels.
4. The fuel nozzle as in claim 1 , wherein the inner tube of the gas-only cartridge at least partially defines an air passage within the gas-only cartridge.
5. The fuel nozzle as in claim 4 , wherein the fuel distribution tip of the gas-only cartridge defines an aperture disposed along a downstream surface of the fuel distribution tip, wherein the aperture is in fluid communication with the air passage at least partially defined by the inner tube.
6. The fuel nozzle as in claim 4 , wherein a flange of the gas-only cartridge at least partially defines at least one air circuit, wherein the air circuit is in fluid communication with the air passage at least partially defined by the inner tube.
7. The fuel nozzle as in claim 1 , wherein at least one fuel port of the plurality of fuel ports of the fuel distribution tip is axially offset from a circumferentially adjacent fuel port of the fuel distribution tip.
8. The fuel nozzle as in claim 1 , wherein a flange of the gas-only cartridge is formed to connect to an outer surface of an end cover of a gas turbine combustor.
9. A combustor, comprising:
an end cover coupled to an outer casing;
a fuel nozzle having a base portion coupled to one side of the end cover, the fuel nozzle comprising:
a center body coupled to and coaxially aligned with the base portion;
a tip body disposed at a downstream end of the center body, the tip body defining an opening that extends axially through the tip body and including a plurality of channels circumferentially spaced and positioned along an inner surface of the tip body within the opening, wherein each channel defines a flow passage through an upstream surface and a downstream surface of the tip body; and
a gas-only cartridge that extends axially within the center body, the gas-only cartridge having an outer tube, an inner tube extending axially within the outer tube and a fuel passage defined therebetween, wherein the outer tube and the centerbody define a secondary premix air passage therebetween, the gas-only cartridge further comprising a fuel distribution tip that extends at least partially through the opening of the tip body, the fuel distribution tip including a plurality of circumferentially spaced fuel ports in fluid communication with the fuel passage, wherein each fuel port is in fluid communication with a respective channel of the tip body and each channel is in fluid communication with the secondary premix air passage.
10. The fuel nozzle as in claim 9 , wherein the inner surface of the tip body forms multiple seals against an outer surface of the fuel distribution tip between each circumferentially adjacent channel of the plurality of channels.
11. The gas turbine as in claim 9 , wherein the inner tube of the gas-only cartridge at least partially defines an air passage within the gas-only cartridge, wherein the fuel distribution tip of the gas-only cartridge defines at least one aperture disposed along a downstream surface of the fuel distribution tip, and wherein the aperture is in fluid communication with the air passage at least partially defined by the inner tube.
12. The gas turbine as in claim 9 , wherein at least one fuel port of the plurality of fuel ports of the fuel distribution tip is axially offset from a circumferentially adjacent fuel port of the fuel distribution tip.