Axial swirler

Patent metadata

Field	Value
Publication number	US-2016010856-A1
Application number	US-201514793775-A
Country	US
Kind code	A1
Filing date	Jul 8, 2015
Priority date	Jul 10, 2014
Publication date	Jan 14, 2016
Grant date	—

Abstract

The present invention relates to an axial swirler, in particular for premixing of oxidizer and fuel in gas turbines. The axial swirler for a gas turbine burner includes a plurality of swirl vanes with a streamline cross-section being arranged around a swirler axis and extending in radial direction between an inner radius R min and an outer radius R max . Each swirl vane has a leading edge, a trailing edge, and a suction side and a pressure side extending each between the leading and trailing edges. A discharge flow angle a between a tangent to the swirl vane camber line at its trailing edge and the swirler axis is first function of radial distance R from the swirler axis. A position of maximum camber of the swirl vane is second function of radial distance R from the swirler axis. At least one swirl vane of the first and second functions include each a respective local maximum and local minimum values along said radial distance from R min to R max . The invention also relates to a burner with such a swirler.

First claim

1 . An axial swirler for a gas turbine burner, comprising a plurality of swirl vanes with a streamline cross-section being arranged around a swirler axis and extending in radial direction between an inner radius (R min ) and an outer radius (R max ), each swirl vane having a leading edge, a trailing edge, and a suction side and a pressure side extending each between said leading and trailing edges, wherein a discharge flow angle (α) between a tangent to the swirl vane camber line ( 27 ) at its trailing edge and the swirler axis is a first function of a radial distance (R) from the swirler axis, and a position of maximum camber of the swirl vane is a second function of a radial distance (R) from the swirler axis,
wherein at least one swirl vane said first and second functions comprise each a respective local maximum and local minimum values along said radial distance from R min to R max .

2 . The axial swirler according to claim 1 , wherein said first function of radial distance (R) from the swirler axis, and/or second function of radial distance (R) from the swirler axis is periodic function.

3 . The axial swirler according to claim 1 , wherein a period of said first function of radial distance (R) from the swirler axis, or/and said second function of radial distance (R) from the swirler axis is from 1 to 100 mm, preferably in the range 20-60 mm.

4 . The axial swirler according to claim 1 , wherein said first function of radial distance (R) from the swirler axis, and/or second function of radial distance (R) from the swirler axis is a sinusoidal function.

5 . The axial swirler according to claim 1 , wherein said first function of radial distance (R) from the swirler axis, and said second function of radial distance (R) from the swirler axis are substantially in phase from R min to R max .

6 . The axial swirler according to claim 1 , wherein said first periodic function of radial distance (R) from the swirler axis is given by a function:
α 0 +R b α*sin(2 πNR )

where α 0 is fixed angle, α* is maximum angle deviation, b and N are rational numbers.

7 . The axial swirler claim 1 , wherein all the swirl vanes are identically formed and/or in that the swirl vanes are arranged around the swirler axis in a circle.

8 . The axial swirler claim 1 , wherein the said first function of radial distance (R) from the swirler axis of two adjacent vanes are in phase or are inverted out of phase.

9 . A burner for a combustion chamber of a gas turbine, the burner comprising an axial swirler according to claim 1 .

10 . The burner according to claim 9 , further comprising fuel injection means.

11 . The burner according to claim 10 , wherein at least one of the swirl vanes is configured as an injection device with at least one fuel nozzle for introducing at least one fuel into the burner.

12 . The burner according to claim 10 , wherein fuel is injected on the suction side of at least one swirl vane.

13 . The burner according to any of claim 10 , wherein fuel is injected on the pressure side ( 23 ) of at least one swirl vane.

Assignees

• Alstom Technology Ltd

Inventors

• Biagioli Fernando
• Poyyapakkam Madhavan Narasimhan
• Wysocki Stefan

Classifications

• F23D14/24

  at least one of the fluids being submitted to a swirling motion · CPC title

• F23D14/02 Primary

  Premix gas burners, i.e. in which gaseous fuel is mixed with combustion air upstream of the combustion zone · CPC title

• F23C2900/07001

  Air swirling vanes incorporating fuel injectors · CPC title

• F23R3/14 Primary

  by using swirl vanes · CPC title