Dual action fuel injection nozzle

1. A fuel injection nozzle comprising:

a nozzle body, the nozzle body defining a central bore;

a fuel atomizer disposed in the central bore, the fuel atomizer defining a spill-return bore and a swirl chamber, the swirl chamber in fluid communication with the central bore, the spill-return bore including a return swirler proximate the swirl chamber; and

an air supply pump coupled to the fuel atomizer and in fluid communication with the spill-return bore, wherein the air supply pump is configured to selectively inject air into the swirl chamber through the spill-return bore.

2. The fuel injection nozzle of claim 1 , including a switch valve in fluid communication with the spill-return bore and the air supply pump.

3. The fuel injection nozzle of claim 2 , including a fuel return in fluid communication with the switch valve.

4. The fuel injection nozzle of claim 2 , including a controller coupled to the switch valve and configured to selectively couple the spill-return bore to one of the air supply pump and the fuel return.

5. The fuel injection nozzle of claim 1 , including a cooling jacket coupled to the nozzle body and configured to provide cooling fluid to a fluid cooling chamber defined by the cooling jacket and the nozzle body.

6. The fuel injection nozzle of claim 1 , wherein the swirl chamber includes a fuel swirler.

7. The fuel injection nozzle of claim 6 , wherein the fuel swirler includes a plurality of bores defined in the fuel swirler, with each such bore in fluid communication with the swirl chamber and the central bore.

8. The fuel injection nozzle of claim 1 , including a fuel supply coupled to the nozzle body and in fluid communication with the central bore.

9. The fuel injection nozzle of claim 1 , wherein the fuel injection nozzle is coupled to an internal combustion engine.

10. The fuel injection nozzle of claim 9 , wherein the internal combustion engine is a gas turbine.

11. A fuel injection system for an internal combustion engine, comprising:

a fuel supply; and

a fuel injection nozzle coupled to the fuel supply, the fuel injection nozzle comprising:

a nozzle body, the nozzle body defining a central bore;

a fuel atomizer disposed in the central bore, the fuel atomizer defining a spill-return bore and a swirl chamber, the swirl chamber in fluid communication with the central bore, the spill-return bore including a return swirler proximate the swirl chamber; and

an air supply pump coupled to the fuel atomizer and in fluid communication with the spill-return bore, wherein the air supply pump is configured to selectively inject air into the swirl chamber through the spill-return bore, and wherein the fuel supply is coupled to the nozzle body and in fluid communication with the central bore.

12. The fuel injection system for an internal combustion engine of claim 11 , including a switch valve in fluid communication with the spill-return bore and the air supply pump.

13. The fuel injection system for an internal combustion engine of claim 12 , including a fuel return in fluid communication with the switch valve.

14. The fuel injection system for an internal combustion engine of claim 12 , including a controller coupled to the switch valve and configured to selectively couple the spill-return bore to one of the air supply pump and the fuel return.

15. The fuel injection system for an internal combustion engine of claim 11 , including a cooling jacket coupled to the nozzle body and configured to provide cooling fluid to a fluid cooling chamber defined by the cooling jacket and the nozzle body.

16. The fuel injection system for an internal combustion engine of claim 11 , wherein the swirl chamber includes a fuel swirler.

17. The fuel injection system for an internal combustion engine of claim 16 , wherein the fuel swirler includes a plurality of bores defined in the fuel swirler, with each such bore in fluid communication with the swirl chamber and the central bore.

18. The fuel injection system for an internal combustion engine of claim 11 , wherein the internal combustion engine is a gas turbine.

19. A method of increasing atomization performance of a fuel injection nozzle, the nozzle including a nozzle body defining a central bore, a fuel atomizer disposed in the central bore, the fuel atomizer defying a spill-return bore and a swirl chamber, with the swirl chamber in fluid communication with the central bore, the method comprising:

coupling an air supply pump to the fuel atomizer, the air supply pump in fluid communication with the spill-return bore; and

injecting air selectively into the swirl chamber through the spill-return bore,

wherein the fuel injection nozzle is changed from pressure-atomization to air-assist atomization.

20. The method of increasing atomization performance of a fuel injection nozzle of claim 19 , including the step of inserting a return swirler in the spill-return bore proximate the swirl chamber, wherein the return swirler is configured to swirl the injected air.

21. The method of increasing atomization performance of a fuel injection nozzle of claim 19 , including a switch valve in fluid communication with the spill-return bore and the air supply pump, wherein air flow into the spill-return bore is selected.

22. The method of claim 19 further including the step of:

injecting fuel into the swirl chamber through a fuel swirler simultaneously with the step of injecting air selectively into the swirl chamber through the spill-return bore, such that the injected fuel and air mix to supply atomized fuel.

23. The fuel injection system of claim 11 , wherein the fuel injection system is configured such that the fuel supply and air supply pump are configured to simultaneously inject fuel and air into the swirl chamber to form a mixture of atomized air and fuel to be supplied to the internal combustion engine to power, continuously, the internal combustion engine.