Effervescence injector for an aero-mechanical system for injecting air/fuel mixture into a turbomachine combustion chamber

• US 20060059915A1
• Filed: 09/22/2005
• Published: 03/23/2006
• Est. Priority Date: 09/23/2004
• Status: Active Grant

• Current Assignee: Safran Aircraft Engine Company
• Original Assignee: Snecma (Safran SA)
• Inventors: Noel, Thomas Olivier Marie, Vasilev, Alexander Jurevich, Yagodkin, Victor Ivanovich, Furletov, Victor Ivanovich, Rollin, Gilles Louis
• Granted Patent: US 7,568,345 B2
• Time in Patent Office: Days
• US Class Current: 60/740
• CPC Class Codes: F23D 11/24 by pressurisation of the fuel before a nozzle through which it is sprayed by a substantial pressure reduction into a space
• CPC Class Codes: F23R 3/286 having fuel-air premixing devices F23R3/30 takes precedence
• CPC Class Codes: F23R 3/30 comprising fuel prevapourising devices

Abstract

A fuel injector for an aero-mechanical injection system for injecting an air/fuel mixture into a turbomachine combustion chamber, the injector comprising a main tubular structure of axis XX′ opening out at a downstream end for delivering the air/fuel mixture, a tubular fuel duct that is disposed inside the main structure and that opens out into the main structure via a fuel atomizer plug so as to introduce fuel into the main structure at a pressure P_C into the main structure, at least one air feed channel that opens out into the main structure so as to introduce air at a pressure P_A therein, and means for injecting into the fuel duct a gas at a pressure P_G that is greater than P_A and greater than or equal to P_C so as to create effervescence in the fuel on being introduced into the main structure.

Claims

1. A fuel injector for an aero-mechanical injection system for injecting an air/fuel mixture into a turbomachine combustion chamber, the injector comprising:

a main tubular structure of axis XX′

opening out at a downstream end for delivering the air/fuel mixture;

a tubular fuel duct disposed inside the main structure so as to co-operate therewith to form an annular passage, and opening out at a downstream end into the main structure via a fuel atomizer plug so as to introduce fuel at a pressure P_C into the main structure; and

at least one air feed channel connected to a compressor stage of the turbomachine and opening out into the annular passage in such a manner as to introduce air at a pressure P_A into said passage;

the injector further comprising a tubular gas duct disposed inside the fuel duct and having a plurality of orifices opening out into said fuel duct to inject therein a gas at a pressure P_G that is greater than P_A and greater than or equal to P_C so as to create effervescence in the fuel on being introduced into the main structure, the orifices of the gas duct being disposed in at least one common transverse plane.

2. An injector according to claim 1, wherein the orifices of the gas duct open out substantially perpendicularly into the fuel duct.

3. An injector according to claim 1, wherein the fuel atomizer plug comprises a cylindrical portion centered on the axis XX′

, having an outside diameter that is smaller than the inside diameter of the fuel duct, and provided with a plurality of profiled fins extending radially outwards, said fins having outside surfaces coming into contact with an inside surface of the fuel duct.

4. An injector according to claim 3, wherein the profiled fins of the fuel atomizer plug are distributed regularly over the entire circumference of the cylindrical portion.

5. An injector according to claim 3, wherein the profiled fins of the fuel atomizer plug present angular twist in a common direction.

6. An injector according to claim 5, wherein the angular twist of the profiled fins is at about 45°

relative to the axis XX′

.

7. An injector according to claim 1, wherein the orifices of the gas duct open out into the fuel duct through the fuel atomizer plug.

8. An injector according to claim 3, wherein the orifices of the gas duct open out into the fuel duct through the fuel atomizer plug between pairs of adjacent fins thereof.

9. An injector according to claim 8, wherein the orifices of the gas duct open out tangentially into the gas duct.

10. An injector according to claim 1, wherein the orifices of the gas duct open out into the fuel duct upstream from the fuel atomizer plug.

11. An injector according to claim 1, further comprising a device for controlling the flow rate of the gas injected into the fuel duct.

12. An aero-mechanical injection system for injecting an air/fuel mixture into a turbomachine combustion chamber, the system comprising a fuel injector according to claim 1, centered on the axis YY′

of the injection system, and means for injecting air downstream from the fuel injector.

13. A system according to claim 12, including an inner air swirler disposed downstream from the injector enabling air to be injected in a radial direction, an outer air swirler disposed downstream from the inner air swirler, and serving to inject air in a radial direction, a Venturi interposed between the inner and outer air swirlers, and a bowl mounted downstream from the outer air swirler.

14. A system according to claim 12, comprising an inner air swirler disposed downstream from the injector and enabling air to be injected in a radial direction, an outer air swirler disposed downstream from the inner air swirler and enabling air to be injected into a radial direction, a first Venturi interposed between the inner and outer air swirlers, a second Venturi disposed downstream from the outer air swirler, and a pre-mixer and/or pre-vaporization tube disposed downstream from the second Venturi.

15. A turbomachine combustion chamber including a fuel injector according to claim 1.

16. A turbomachine including a combustion chamber fitted with a fuel injector according to claim 1.