PILOT NOZZLE HEAT SHIELD HAVING INTERNAL TURBULATORS

• US 20100095677A1
• Filed: 05/11/2006
• Published: 04/22/2010
• Est. Priority Date: 05/11/2006
• Status: Active Grant

• Current Assignee: Siemens Energy Incorporated (Siemens AG)
• Original Assignee: Siemens Power Generation, Inc.
• Inventors: King, Richard E. JR., Dawson, Robert W., Ras, Raman, Sanford, Richard L.
• Granted Patent: US 7,762,070 B2
• Time in Patent Office: Days
• US Class Current: 60/752
• CPC Class Codes: F23D 14/76 Protecting flame and burner parts
• CPC Class Codes: F23D 2900/00018 Means for protecting parts of the burner, e.g. ceramic lining outside of the flame tube
• CPC Class Codes: F23R 3/343 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

Abstract

A pilot nozzle heat shield includes a body having a first end for receiving a pilot nozzle and a second end including a flow tip. The body includes a plurality of internal turbulators circumferentially disposed about the internal peripheral surface of the body. The flow tip includes a proximal periphery and a distal periphery. A plurality of flow ports are circumferentially spaced about the proximal periphery of the flow tip. The flow tip includes a plurality of slots. Each slot extends distally from one of the flow ports to the distal periphery of the flow tip, which defines an aperture. The plurality of slots define a plurality of tangs; each tang is defined between a pair of neighboring slots. A plurality of turbulators can be disposed about the inner peripheral surface of the heat shield body at the tangs.

Claims

1. A pilot nozzle heat shield comprising:

a heat shield body having a first end region including a first end and a second end region including a second opposite end, the body having an internal cavity opening to the first end for receiving a pilot nozzle, the heat shield body having an inner peripheral surface and an outer peripheral surface, wherein the body has a longitudinal axis extending from the first end to the second end;

the second end region including a flow tip, the flow tip extending from a proximal periphery to a distal periphery defining an aperture, a plurality of flow ports extending through the heat shield body and spaced about the proximal periphery of the flow tip, the flow tip further including a plurality of through slots, each through slot extending distally from one of the plurality of flow ports to the aperture, the through slots defining sets of tangs therebetween; and

at least one internal turbulator disposed on the inner peripheral surface of the body, the internal turbulator being located proximate and upstream of the flow tip.

2. The pilot nozzle heat shield of claim 1 wherein the heat shield body further includes at least one tang turbulator disposed about the inner peripheral surface of the heat shield body located at the tangs.

3. The pilot nozzle heat shield of claim 1 wherein the heat shield is manufactured from a heat resistant weldable alloy that includes iron and at least two other materials selected from the group consisting of:

aluminum, boron, carbon, chromium, cobalt, copper, manganese, molybdenum, nickel, phosphorus, silicon, sulfur, titanium and tungsten.

4. The pilot nozzle heat shield of claim 1 wherein the tangs angle concentrically inward at an angle between about 25 degrees and about 90 degrees relative to the longitudinal axis of the heat shield body.

5. The pilot nozzle heat shield of claim 1 wherein the tangs angle concentrically inward at an angle between about 25 degrees and about 65 degrees relative to the longitudinal axis of the heat shield body.

6. The pilot nozzle heat shield of claim 1 wherein the heat shield body includes a plurality of retention pin passages and wherein at least one of the retention pin passages is reinforced by a ring of a heat resistant alloy material disposed about the periphery of the heat shield.

7. The pilot nozzle heat shield of claim 1 wherein the first end region has an internal taper for receiving the pilot nozzle.

8. A pilot nozzle heat shield for use in a gas turbine engine comprising:

a generally cylindrical body having a first end region including a first end and a second end region including a second opposite end, wherein the body has a longitudinal axis extending from the first end to the second end, the heat shield body having an inner peripheral surface and a outer peripheral surface, the body being manufactured from a heat resistant weldable alloy, the body further comprising at least one internal turbulator disposed circumferentially about the internal peripheral surface of the body for mixing cooling air passing therethrough,

the second end region of the body includes a frustoconical flow tip, the frustoconical flow tip comprising a proximal periphery and a distal periphery defining an aperture and further comprising a plurality of slots, each slot extending distally from one of a plurality of flow ports circumferentially disposed about the proximal periphery of the frustoconical flow tip to the aperture, the slots defining tangs therebetween, wherein at least two of the tangs are provided on the flow tip.

9. The pilot nozzle heat shield of claim 8 wherein the heat shield body further includes at least one tang turbulator disposed about the inner peripheral surface of the heat shield body located at the tangs.

10. The pilot nozzle heat shield of claim 8 wherein the heat resistant weldable alloy includes iron and at least two other materials selected from the group consisting of:

aluminum;

boron;

carbon;

chromium;

cobalt;

copper;

manganese;

molybdenum;

nickel;

phosphorus;

silicon;

sulfur;

titanium; and

tungsten.

11. The pilot nozzle heat shield of claim 8 wherein the tangs angle concentrically inward at an angle between about 25 degrees and about 65 degrees relative to the longitudinal axis of the heat shield body.

12. The pilot nozzle heat shield of claim 11 wherein the heat shield comprises between three and four retention pin passages and wherein the retention pin passages are reinforced by an annular ring of heat resistant alloy material disposed about the periphery of the heat shield.

13. A pilot nozzle for use in a gas turbine engine comprising:

a pilot nozzle having a distal end, the pilot nozzle including a plurality of castellations disposed proximate to the distal end; and

a heat shield having body with a first end region including a first end and a second end region including an opposite second end, wherein the body has a longitudinal axis extending from the first end to the second end, the heat shield body having an inner peripheral surface and an outer peripheral surface, the body having an internal cavity opening to the first end, the body further comprising at least one internal turbulator disposed circumferentially about the internal peripheral surface of the body for mixing cooling air passing therethrough,

the second end region of the body includes a frustoconical flow tip, the frustoconical flow tip having a proximal periphery and a distal periphery defining an aperture, the flow tip including a plurality of slots, wherein each slot extends distally from one of a plurality of flow ports circumferentially disposed about the proximal periphery of the frustoconical flow tip to the aperture, the slots defining tangs therebetween, wherein at least two of the tangs are provided on the flow tip,

wherein at least a portion of the pilot nozzle including the distal end extends into the internal cavity.

14. The pilot nozzle heat shield of claim 13 wherein the heat shield body further includes at least one tang turbulator disposed about the inner peripheral surface of the heat shield body located at the tangs.

15. The pilot nozzle of claim 13 wherein the tangs angle concentrically inward at an angle between about 25 degrees and about 65 degrees relative to the longitudinal axis of the heat shield.

16. The pilot nozzle of claim 13 wherein the heat shield is manufactured from a heat resistant weldable alloy including iron and at least two other materials selected from the group consisting of:

aluminum, boron, carbon, chromium, cobalt, copper, manganese, molybdenum, nickel, phosphorus, silicon, sulfur, titanium and tungsten.

17. The pilot nozzle of claim 13 wherein at least one of the castellations is characterized by a radial height and the nozzle is characterized by a nozzle thickness, wherein the ratio of the radial height to the nozzle thickness is in the range of about 0.25 to about 0.75.

18. The pilot nozzle of claim 17, wherein the ratio of radial height to nozzle thickness is about 0.5.

19. The pilot nozzle of claim 13, wherein at least one of the castellations is characterized by a wall thickness and the fuel jet is characterized by a jet diameter, wherein the ratio of the wall thickness to the jet diameter is in the range of about 0.25 to about 5.0.

20. The pilot nozzle of claim 19, wherein the ratio of the wall thickness to the jet diameter is about 1:

1.