Apparatus and method for a gas turbine entrainment system

• US 8,015,821 B2
• Filed: 01/11/2008
• Issued: 09/13/2011
• Est. Priority Date: 01/11/2008
• Status: Active Grant

• Current Assignee: Spytek Aerospace Corporation
• Original Assignee: Spytek Aerospace Corporation
• Inventors: Spytek, Christopher J.
• Primary Examiner(s): KIM, TAE JUN
• Application Number:
  US12/013,085
• Publication Number:
  US 20090178412A1
• Time in Patent Office: 1,341 Days
• Field of Search: 607/72, 60/395, 607/46, 607/48, 60/391.7
• US Class Current: 60/772
• CPC Class Codes: F02C 3/14 characterised by the arrangement of the combustion chamber in the plant combustion chambers per se F23R; F02C3/205 takes precedence
• CPC Class Codes: F02C 6/003 Gas-turbine plants with heaters between turbine stages
• CPC Class Codes: F05D 2250/25 helical
• CPC Class Codes: F05D 2260/2212 by creating turbulence
• CPC Class Codes: F05D 2260/60 Fluid transfer
• CPC Class Codes: F23M 9/08 Helical or twisted baffles or deflectors
• CPC Class Codes: F23R 3/58 Cyclone or vortex type combustion chambers
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

This invention relates to an apparatus for an entrainment system of a vortex burning combustion chamber or a vortex burning inter-turbine burner in a gas turbine. The entrainment system rapidly and thoroughly mixes hot combustion gases with non-combustion gases to reduce the gas temperature before entering a turbine. The entrainment system includes a plurality of helical vanes forming trenches and resulting in a highly helical flow path. The highly helical flow path provides an increased residence time for mixing of the combustion gases and non-combustion gases. Radial cavities in the helical vanes, canted vane angles and varying geometries further facilitate mixing while reducing losses. This invention also includes a method of mixing combustion and non-combustion gases in an entrainment system.

Claims

1. A gas turbine entrainment system for mixing combustion gases and non-combustion gases, the entrainment system comprising:

an axial body having a first end and a second end;

a plurality of helical vanes radially disposed with respect to the axial body, each of the helical vanes having a root attached to the axial body and a tip opposite the root; and

a plurality of trenches formed by the helical vanes, each trench radially receiving combustion gases from the tip towards the root, each trench receiving non-combustion gases from the first end of the axial body to the second end of the axial body in a helical flow path to quench the combustion gases with the non-combustion gases.

2. The entrainment system of claim 1 wherein the helical flow path is between about 45 degrees and about 85 degrees from an axis of the axial body.

3. The entrainment system of claim 1 wherein helical flow path has an effective length of at least about 1.2 times an axial length of the axial body.

4. The entrainment system of claim 1 wherein the plurality of helical vanes comprises between about 5 helical vanes and about 15 helical vanes generally equally radially disposed circumferentially with respect to the axial body.

5. The entrainment system of claim 1 further comprising at least one radial cavity formed in a leading side of each helical vane for conducting combustion gases into the trench and increasing mixing.

6. The entrainment system of claim 5 wherein:

a first radial cavity is disposed at between about 15 percent and about 35 percent of a length of the helical vane;

a second radial cavity is disposed at between about 40 percent and about 60 percent of the length of the helical vane; and

a third radial cavity is disposed at between about 65 percent and about 85 percent of the length of the helical vane.

7. The entrainment system of claim 5 wherein a depth of each radial cavity is between about 10 percent and about 50 percent of a thickness of the helical vane.

8. The entrainment system of claim 5 wherein a length of each radial cavity is between about 10 percent and about 30 percent of a length of the helical vane.

9. The entrainment system of claim 1 wherein:

the first end of the axial body is in fluid communication with an air compressor; and

the second end of the axial body is in fluid communication with a power turbine.

10. The entrainment system of claim 1 wherein the gas turbine comprises at least one of the group consisting of vortex burning combustion chambers, vortex burning inter-turbine burners and combinations thereof.

11. The entrainment system of claim 1 wherein a profile of each trench has as a canted V-shape at the tip and widens into a parallelogram shape at the root.

12. The entrainment system of claim 11 wherein a width of each trench increases along a length of each helical vane from the first end of the axial body to the second end of the axial body.

13. The entrainment system of claim 11 wherein each trench is tilted between about 2 degrees and about 20 degrees from the root to the tip toward the first end of the axial body for mixing combustion gases and non-combustion gases.

14. The entrainment system of claim 1 further comprising a splay deflector bridging across each trench with respect to the first end of the axial body and the tip of each helical vane forming each trench, the spay deflector directing a portion of the non-combustion gases radially outward.

15. A gas turbine entrainment system for mixing combustion gases and non-combustion gases, the entrainment system comprising:

an axial body having a first end and a second end, the axial body disposed within an inner radius of a vortex combustion chamber;

ten helical vanes generally equally radially disposed circumferentially with respect to the axial body, each of the helical vanes having a root attached to the axial body and a tip opposite the root;

ten trenches formed by the helical vanes, each trench radially receiving combustion gases from the tip towards the root, each trench is tilted between about 8 degrees and about 12 degrees from the root to the tip toward the first end of the axial body, each trench receiving non-combustion gases from the first end of the axial body to the second end of the axial body in a helical flow path to quench the combustion gases with the non-combustion gases, wherein the helical flow path is between about 65 degrees and about 70 degrees from an axis of the axial body;

a first radial cavity having a depth of between about 25 percent and about 35 percent of a thickness of the helical vane and a length of between about 15 percent and about 25 percent of a length of the helical vane, the first radial cavity is disposed at between about 20 percent and about 30 percent of the length of the helical vane;

a second radial cavity having a depth of between about 25 percent and about 35 percent of the thickness of the helical vane and a length of between about 15 percent and about 25 percent of the length of the helical vane, the second radial cavity is disposed at between about 45 percent and about 55 percent of the length of the helical vane;

a third radial cavity having a depth of between about 25 percent and about 35 percent of the thickness of the helical vane and a length of between about 15 percent and about 25 percent of the length of the helical vane, the third radial cavity is disposed at between about 70 percent and about 80 percent of the length of the helical vane;

a profile of each trench has a canted V-shape at the tip and widens into a parallelogram shape at the root; and

a width of each trench increases along the length of the helical vane from the first end of the axial body to the second end of the axial body.

16. A method of mixing combustion and non-combustion gases in a gas turbine, the method comprising:

compressing ambient air in an air compressor forming compressed air;

splitting the compressed air into combustion air and non-combustion gases;

mixing fuel and combustion air in a vortex burning combustion chamber including an inner radius and an entrainment system within the inner radius;

burning fuel and combustion air in the vortex burning combustion chamber, forming combustion gases;

quenching the combustion gases with the non-combustion gases in an entrainment system including an axial body and, disposed within the axial body, helical canted vanes forming trenches, each vane including a root and a tip opposite the root, the quenching forms quenched gases; and

powering a turbine with the quenched gases;

wherein each trench receives combustion gases from the tip toward the root of a corresponding helical canted vane, and each trench receives non-combustion gases from a first end of the axial body to a second end of the axial body in a helical flow path to quench the combustion gases with the non-combustion gases.

17. The method of claim 16 wherein the combustion air is between about 15 percent and about 40 percent of a mass of the compressed air and the non-combustion gases is between about 60 percent and about 85 percent of the mass of the compressed air.

18. The method of claim 16 wherein a drawdown of the combustion gases into the trench occurs between about 30 percent and about 65 percent of the length of the canted helical vane.

19. The method of claim 16 wherein:

mixing of the fuel and combustion air occurs at between about 10 meters per second and about 60 meters per second;

burning of the fuel and combustion air occurs at between about 1,500 degrees Celsius and about 2,000 degrees Celsius; and

quenching results in quenched gases having a uniform temperature of between about 975 degrees Celsius and about 1,375 degrees Celsius.

20. The method of claim 16 wherein splitting occurs within the entrainment system having a splay deflector.