Axial swirler for a gas turbine burner

Patent metadata

Field	Value
Publication number	US-9518740-B2
Application number	US-201313937482-A
Country	US
Kind code	B2
Filing date	Jul 9, 2013
Priority date	Jul 10, 2012
Publication date	Dec 13, 2016
Grant date	Dec 13, 2016

Abstract

An axial swirler for a gas turbine burner includes a vane ring with a plurality of swirler vanes circumferentially distributed around a swirler axis. Each of the swirler vanes includes a trailing edge. In order to achieve a controlled distribution of the exit flow velocity profile and/or the fuel equivalence ratio in the radial direction. The trailing edge is discontinuous with the trailing edge having a discontinuity at a predetermined radius.

First claim

What is claimed is:

1. An axial swirler for a gas turbine burner, the axial swirler comprising:
a vane ring with a plurality of swirler vanes circumferentially distributed around a swirler axis and extending in a radial direction between an inner radius and an outer radius, each of said swirler vanes comprising a trailing edge that extends between the inner radius and the outer radius of the swirler vane, the trailing edge configured to define a controlled distribution of an exit flow velocity profile and/or a fuel equivalence ratio in the radial direction,
wherein said trailing edge is discontinuous with the trailing edge having a discontinuity at a predetermined radius to define an apex of the trailing edge, a first segment of the trailing edge extending from the inner radius to the apex and a second segment of the trailing edge extending from the apex to the outer radius, wherein the trailing edge is configured so that at the inner radius an exit flow angle of fluid passing along the swirler vane between a tangent to a camber line of the swirler vane and a swirler axis is between 0° and 30°, the exit flow angle is linearly increasing to a value of between 30° and 60° from the inner radius to the predetermined radius, and the exit flow angle is linearly decreasing to a value of between 10° and 40° from the predetermined radius to the outer radius.

2. The axial swirler according to claim 1 , wherein the trailing edge is configured so that the exit flow angle at the inner radius is between 10° and 28°, the exit flow angle from the inner radius to the predetermined radius is linearly increasing to a value of between 35° and 50° at the predetermined radius, and from the predetermined radius to the outer radius is linearly decreasing to a value of between 20° and 40° at the outer radius.

3. The axial swirler according to claim 1 , wherein the trailing edge is configured so that the exit flow angle at the inner radius is between 24° and 28°, the exit flow angle from the inner radius to the predetermined radius is linearly increasing to a value of between 42° and 46°, and the exit flow angle from the predetermined radius to the outer radius is linearly decreasing to a value of between 36° and 38° at the outer radius.

4. The axial swirler according to claim 1 , wherein the trailing edge linearly extends from the inner radius to the predetermined radius and the trailing edge linearly extends from the predetermined radius to the outer radius of the swirler vane, the discontinuity at the predetermined radius defining the apex being a point at which the trailing edge extends farthest away from a leading edge of the swirler vane that is opposite the trailing edge of the swirler vane.

5. The axial swirler according to claim 1 , wherein said predetermined radius has a value of between 20% and 80% of a difference between the outer radius and the inner radius.

6. The axial swirler according to claim 1 , wherein said discontinuous trailing edge is formed as a result of two different prescribed types of flow, each with a predetermined flow velocity profile in a swirling flow at an exit of the axial swirler, wherein the first segment of the trailing edge between the inner radius and the predetermined radius is configured to generate a jet like axial velocity distribution and the second segment of the trailing edge between said predetermined radius and the outer radius is configured to level off the axial velocity distribution above flashback values.

7. The axial swirler according to claim 6 , wherein said predetermined flow velocity profiles of the two flow types do not mix with each other and therefore allow for a controlled distribution of the fuel equivalence ratio in the radial direction.

8. The axial swirler according to claim 1 , wherein said swirler vanes have a suction side and a pressure side, and at least one fuel injector is on the pressure side.

9. The axial swirler according to claim 1 , wherein the trailing edge is configured so that a relationship between a tangential flow component of a flow of the fluid at an exit of the swirler vane and an axial flow component of the flow of the fluid at the exit of the swirler vane is defined by the swirler vane so that the tangential flow component is flat from the inner radius to the predetermined radius and the axial flow component is decreasing from the inner radius to the predetermined radius and the axial flow component is flat from the predetermined radius to the outer radius at the exit of the swirler vane and the tangential flow component is decreasing from the predetermined radius to the outer radius at the exit of the swirler vane.

10. The axial swirler according to claim 9 , wherein the trailing edge is configured so that the flow of the fluid has a radial flow component that is 0 such that there is no mixing of the fluid between an inner section of the flow of the fluid and an outer section of the flow of the fluid.

11. The axial swirler according to claim 1 , wherein the trailing edge is configured so that a relationship between a tangential flow component of a flow of the fluid at an exit of the swirler vane and an axial flow component of the flow of the fluid at the exit of the swirler vane is defined by the swirler vane so that the tangential flow component is unchanging from the predetermined radius to the inner radius and the axial flow component is decreasing from the predetermined radius to the inner radius and the axial flow component is unchanging from the predetermined radius to the outer radius at the exit of the swirler vane and the tangential flow component is decreasing from the predetermined radius to the outer radius at the exit of the swirler vane.

12. The axial swirler according to claim 11 , wherein the trailing edge is configured so that the flow of the fluid has a radial flow component that is 0 such that there is no mixing of the fluid between an inner section of the flow of the fluid passing along the inner radius and an outer section of the flow of the fluid passing along the outer radius.

13. The axial swirler according to claim 12 , wherein the swirler vane is configured to define a predetermined stall at a region of increased turbulence in the flow of the fluid approaching a flame front.

14. The axial swirler according to claim 12 , wherein at least one row of fuel injection ports are defined in the trailing edge.

15. The axial swirler according to claim 14 , wherein the at least one row of the fuel injection ports comprise at least one of:
a row of the fuel injection ports on a suction side extending between a leading edge of the swirler vane and the trailing edge of the swirler vane; and
a row of the fuel injection ports on a pressure side of the trailing edge extending between the leading edge and the trailing edge.

16. The axial swirler of claim 12 , wherein the trailing edge has a splitting radius configured to divide the flow of the fluid into the inner section of the flow of the fluid and the outer section of the flow of the fluid.

17. The axial swirler of claim 16 , wherein the splitting radius is located at the discontinuity defined in the trailing edge.

18. A method of using an axial swirler for a gas turbine burner, the axial swirler comprising a vane ring with a plurality of swirler vanes circumferentially distributed around a swirler axis and extending in a radial direction between an inner radius and an outer radius, each of said swirler vanes comprising a trailing edge configured to define a controlled distribution of an exit flow velocity profile and/or a fuel equivalence ratio in the

Assignees

• Alstom Technology Ltd
• General Electric Company Gmbh

Inventors

• Biagioli Fernando
• Aluri Naresh
• Poyyapakkam Madhavan Narasimhan
• Cerny Jan

Classifications

• F23C7/004

  using vanes · CPC title

• F23R3/286

  having fuel-air premixing devices (F23R3/30 takes precedence) · CPC title

• F23R3/14 Primary

  by using swirl vanes · CPC title