US 2014/0109587 A1 · SYSTEM AND METHOD FOR REDUCING MODAL COUPLING OF COMBUSTION DYNAMICS

Abstract

A system and method for reducing combustion dynamics includes first and second combustors, and each combustor includes a fuel nozzle and a combustion chamber downstream from the fuel nozzle. Each fuel nozzle includes an axially extending center body, a shroud that circumferentially surrounds at least a portion of the axially extending center body, a plurality of vanes that extend radially between the center body and the shroud, a first fuel port through at least one of the plurality of vanes at a first axial distance from the combustion chamber, the plurality of vanes being located at a second axial distance from the combustion chamber. A second fuel port is provided through the center body at a third axial distance from the combustion chamber. The system further includes structure for producing a combustion instability frequency in the first combustor that is different from the combustion instability frequency in the second combustor.

Claims15

Dependent claims

A system for reducing modal coupling of combustion dynamics, the system comprising:

(a) a plurality of combustors arranged in a circumferential array about a common longitudinal axis, each combustor having a liner defining a combustion chamber and a cap assembly having an axial cap length;
(b) at least one fuel nozzle disposed within each combustor upstream of the combustion chamber, each fuel nozzle being housed within the cap assembly and comprising an axially extending center body, a shroud circumferentially surrounding at least a portion of the axially extending center body and a plurality of vanes extending radially between the center body and the shroud, each vane defining at least a first fuel port located at a first axial distance from the combustion chamber and further comprising a leading edge located at a second axial distance from the combustion chamber;
wherein at least one of the first axial distance and the second axial distance in a first combustor of the plurality of combustors is different from the first axial distance and the second axial distance in a second combustor of the plurality of combustors.

A method of reducing modal coupling of combustion dynamics in a combustion system comprising a plurality of combustors, the method comprising:

(a) providing a first combustor having a first liner defining a first combustion chamber, a first cap assembly, and at least one fuel nozzle housed within the first cap assembly and comprising an axially extending center body, a shroud circumferentially surrounding at least a portion of the axially extending center body and a plurality of vanes extending radially between the center body and the shroud, each vane defining at least a first fuel port located at a first axial distance from the first combustion chamber and further comprising a leading edge located at a second axial distance from the first combustion chamber;
(b) providing a second combustor having a second liner defining a second combustion chamber, a second cap assembly, and at least one fuel nozzle housed within the second cap assembly and comprising an axially extending center body, a shroud circumferentially surrounding at least a portion of the axially extending center body and a plurality of vanes extending radially between the center body and the shroud, each vane defining at least a first fuel port located at a first axial distance from the second combustion chamber and further comprising a leading edge located at a second axial distance from the second combustion chamber;
wherein at least one of (i) the first axial distance in the first combustor is different from the first axial cap distance in the second combustor;
and (ii) the second axial distance in the first combustor is different from the second axial distance in the second combustor.

1 more element

Dependencies are inferred from the claim text.

System and method for reducing modal coupling of combustion dynamics

Life of this patent

System and method for reducing modal coupling of combustion dynamics

Life of this patent

Abstract

Claims15