Mixer
AssigneeAnsaldo Energia Switzerland AG
InventorsMirko Ruben Bothien, Alessandro Scarpato
Life of this patent
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Abstract
A mixer having a housing, a duct within the housing, a first and a second injector arranged to inject a fluid at a centre zone of the duct, a third and a fourth injector arranged to inject the fluid at a wall zone of the duct. The first/third injectors are at a distance D1=v/2f1 or odd integer multiples of it from the second/fourth injectors in the absence of an acoustic node between them, or at a distance D1=λconv=v/f1 or full wave length integer multiples of it in the presence of an acoustic node between them. Advantageously f1 is greater than f2.
Claims18
A method of dampening oscillating frequencies in a gas turbine mixer, the gas turbine mixer comprising a housing, a duct within the housing, a first injector and a second injector, each arranged to inject a fluid at a center zone of the duct, a third injector and a fourth injector, each arranged to inject the fluid at a wall zone of the duct, the method comprising:
- either:
- (a) injecting the fluid through the first injector at a distance D1=v/2f1, or odd integer multiples of D1, from the second injector in the absence of an acoustic node between the second injector and the first injector, or (b) injecting the fluid through the first injector at a distance D1=v/f1, or full wave length integer multiples of D1, in the presence of an acoustic node between the second injector and the first injector,
- and either:
- (c) injecting the fluid through the third injector at a distance D2=v/2f2, or odd integer multiples of D2 from the fourth injector in the absence of an acoustic node between the third injector and the fourth injector, or (d) injecting the fluid through the third injector at a distance D2=v/f2 from the fourth injector in the presence of an acoustic node between the third injector and the fourth injector,
- wherein f1 is an oscillating frequency to be damped at the wall zone of the duct,
- f2 is an oscillating frequency to be damped at the center zone of the duct,
- v is a fluid flow speed through the duct, and
- f1 is greater than f2.
A method of operating a gas turbine, wherein the gas turbine comprises a compressor, a first combustion chamber, a second combustion chamber fed with combustion gases coming from the first combustion chamber, a turbine and a mixer between the first combustion chamber and the second combustion chamber, wherein the mixer comprises a housing, a duct within the housing, a first injector and a second injector, each arranged to inject a fluid at a center zone of the duct, a third injector and a fourth injector, each arranged to inject the fluid at a wall zone of the duct, the method comprising:
- either:
- (a) injecting the fluid through the first injector at a distance D1=v/2f1, or odd integer multiples of D1 from the second injector in the absence of an acoustic node between the second injector and the first injector, or (b) injecting the fluid through the first injector at a distance D1=v/f1, or full wave length integer multiples of D1 in the presence of an acoustic node between the second injector and the first injector,
- and either:
- (c) injecting the fluid through the third injector at a distance D2=v/2f2, or odd integer multiples of D2, from the fourth injector in the absence of an acoustic node between the third injector and the fourth injector, or (d) injecting the fluid through the third injector at a distance D2=v/f2 from the fourth injector in the presence of an acoustic node between the third injector and the fourth injector,
- wherein f1 is an oscillating frequency to be damped at the wall zone of the duct,
- f2 is an oscillating frequency to be damped at the center zone of the duct,
- v is a fluid flow speed through the duct, and
- f1 is greater than f2.
A method of operating a gas turbine, comprising:
- combusting a fuel in a first combustion chamber, thereby producing a hot gas;
- flowing the hot gas through a mixer;
- and
- either:
- (a) injecting a fluid in the mixer at a first injection location at a distance D1=v/2f1, or odd integer multiples of D1, from a second injection location if there are no acoustic nodes between the second injection location and the first injection location, or (b) injecting the fluid at the first injection location at a distance D1=v/f1, or full wave length integer multiples of D1, if there is at least one acoustic node between the second injection location and the first injection location,
- and either:
- (c) injecting the fluid at a third injection location at a distance D2=v/2f2 or odd integer multiples of D2, from a fourth injection location if there are no acoustic nodes between the third injection location and the fourth injection location, or (d) injecting the fluid at the third injection location at a distance D2=v/f2 from the fourth injection location if there is at least one acoustic node between the third injection location and the fourth injection location,
- wherein f1 is an oscillating frequency to be damped at a wall zone of a duct of the mixer,
- f2 is an oscillating frequency to be damped at a center zone of the duct,
- v is a fluid flow speed through the duct, and
- f1 is greater than f2.
Dependencies are inferred from the claim text.