Dry low emission combustor for gas turbine engines

Claim 2

The combustor assembly in Claim 1, wherein said fueling pathway has apertures located upstream of the axial midpoint of said vaned swirler.

Claim 3

The combustor assembly in Claim 1, wherein said vaned swirler further comprises a plurality of vanes having chords varying with radial distance from said centerbody.

Claim 4

The combustor assembly in Claim 1, wherein said vaned swirler further comprises a plurality of vanes, each of said vanes having an airfoil shape for minimizing flow separation and thereby preventing flame stabilization combustion within said premix dome.

Claim 5

A combustor assembly for receiving a flow of fuel from an external source and a flow of air from a compressor, comprising: a combustion housing having an upstream end, a downstream end, and a combustion barrel disposed within said combustion housing; and a premix dome having a downstream end connected to the upstream end of said combustion housing for receiving and substantially premixing the fuel and air prior to delivery to said upstream end of said combustion housing, said premix dome comprising: a centerbody extending longitudinally through said premix dome; a vaned swirler having an inlet and an outlet, said vaned swirler positioned around said centerbody for turning and mixing the fuel and air passing through said premix dome; and a premix chamber located adjacent said swirler, positioned around said centerbody and defining therebetween a cavity having a converging portion for accelerating the flow of fuel and air passing through said premix dome to said upstream end of said combustion housing to inhibit flashback into said premix dome; said centerbody further including a root diameter measured adjacent said outlet of said vaned swirler, a tip located adjacent said downstream end of said premix dome, and a widening portion downstream of said outlet of said vaned swirler, said widening portion having a maximum diameter greater than said root diameter for minimizing disparities in temperatures in said combustion barrel by enlarging the radius of the annulus through which the premixed flow exits said premix chamber and thereby spreading out the air and fuel mixture entering said combustion barrel.

Claim 6

The combustor assembly in Claim 5, wherein said maximum diameter of said widening portion of said centerbody is located at said tip of said centerbody.

Claim 7

The combustor assembly in Claim 5, wherein said maximum diameter of said widening portion of said centerbody is at least about 20% greater than said root diameter of said centerbody.

Claim 8

The combustor assembly in Claim 7, wherein said maximum diameter of said widening portion of said centerbody is at least about 100% greater than said root diameter of said centerbody.

Claim 9

The combustor assembly in Claim 5, wherein said maximum diameter of said widening portion of said centerbody is at least about 35% of the diameter of said combustor barrel measured at said upstream end of said combustion housing.

Claim 10

The combustor assembly in Claim 5, wherein said maximum diameter of said widening portion of said centerbody is at least about 55% of the diameter of said combustor barrel measured at said upstream end of said combustion housing.

Claim 11

The combustor assembly in Claim 5, wherein the diameter of said tip of said centerbody is at least about 20% of the diameter of said combustion barrel measured at said upstream end of said combustion housing.

Claim 12

The combustor assembly in Claim 5, wherein said combustion barrel has an inner surface with a thermal barrier ceramic coating deposited thereon for protecting said combustion barrel and maintaining said inner surface of said combustion barrel at a temperature higher than is possible without said coating thereby reducing the combustion reaction quenching effect on reactions involving carbon monoxide and unburned hydrocarbons.

Claim 13

The combustor assembly in Claim 5, wherein said premix dome further comprises an inside wall with a thermal barrier ceramic coating thereon for protecting and maintaining said inside wall at a temperature higher than is possible without said coating thereby reducing the combustion reaction quenching effect on reactions involving carbon monoxide and unburned hydrocarbons.

Claim 14

The combustor assembly in Claim 5, wherein said tip of said centerbody has a thermal barrier ceramic coating deposited thereon for protecting said tip and maintaining said tip at a temperature higher than is possible without said coating thereby reducing the combustion reaction quenching effect on reactions involving carbon monoxide and unburned hydrocarbons.

Claim 15

A combustor assembly for receiving a flow of fuel from an external source and a flow of air from a compressor, comprising: a combustion housing having an upstream end, a downstream end, and a combustion barrel disposed within said combustion housing; and a premix dome having a downstream end connected to the upstream end of said combustion housing for receiving and substantially premixing the fuel and air prior to delivery to said upstream end of said combustion housing, said premix dome comprising: a centerbody extending longitudinally through said premix dome and having a tip located adjacent said downstream end of said premix dome, the area of said tip being at least about 10% of the total area calculated from the diameter of said combustion barrel measured at said upstream end of said combustion housing; a vaned swirler having an outlet, said vaned swirler positioned around said centerbody for turning and mixing the fuel and air passing through said premix dome; and a premix chamber located adjacent said swirler, positioned around said centerbody and defining therebetween a cavity having an outlet with a smaller area than the area of said outlet of said vaned swirler.

Claim 16

The combustor assembly in Claim 15, wherein the area of said tip of said centerbody is at least about 30% of the total area calculated from the diameter of said combustion barrel measured at said upstream end of said combustion housing.

Claim 17

A combustor assembly for receiving a flow of fuel from an external source and a flow of air from a compressor, comprising: a combustion housing have an upstream end and a downstream end; and a premix dome connected to the upstream end of said combustion housing for receiving and substantially premixing the fuel and air prior to delivery to said upstream end of said combustion housing, said premix dome comprising: a centerbody extending longitudinally through said premix dome; a vaned swirler having an inlet, said vaned swirler positioned around said centerbody for turning and mixing the fuel and air passing through said premix dome; and a fueling pathway positioned radially along said swirler for delivering fuel across said swirler, said fueling pathway having an outlet located adjacent said inlet of said vaned swirler.

Claim 18

The combustor assembly in Claim 17, wherein said vaned swirler is fixed relative to said premix dome and includes a plurality of vanes.

Claim 19

The combustor assembly in Claim 18, wherein all of said vanes have approximately the same angular orientation with respect to said centerbody for producing a swirling flow substantially free from localized low-speed and reverse flow regions.

Claim 20

The combustor assembly in Claim 18, wherein said vanes have chords varying with radial distance from said centerbody for imparting a more uniform swirl to the flow of fuel and air.

Claim 21

The combustor assembly in Claim 18, wherein each of said vanes has an airfoil shape for minimizing flow separation and thereby preventing flame stabilization combustion within said premix dome.

Claim 22

The combustor assembly in Claim 18, wherein each of said vanes has a leading edge and a plurality of apertures formed adjacent said leading edge, and said fueling pathway comprises a plurality of fuel passageways formed in said vanes and in flow communication with said apertures of said vanes.

Claim 23

The combustor assembly in Claim 22, wherein said fueling pathway further comprises a plurality of fuel tubes located upstream of said vanes, each of said fuel tubes having fuel outlet holes located adjacent a trailing edge of each of said fuel tubes and radially positioned along each of said fuel tubes so that said fuel outlet holes are staggered with respect to said apertures of said vanes for more evenly dispensing fuel across the air flow.

Claim 24

A combustor assembly for receiving a flow of fuel from an external source and a flow of air from a compressor, comprising: a combustion housing having an upstream end and a downstream end; and a premix dome connected to the upstream end of said combustion housing for receiving and substantially premixing the fuel and air prior to delivery to said upstream end of said combustion housing, said premix dome comprising: a centerbody extending longitudinally through said premix dome; a vaned swirler positioned around said centerbody for turning and mixing the fuel and air passing through said premix dome, said vaned swirler including a plurality of vanes, all of said vanes having substantially the same angular orientation with respect to said centerbody for producing a swirling flow substantially free from localized low-speed and reverse flow regions; and a fueling pathway positioned adjacent said swirler for delivering fuel across said swirler.

Claim 25

The combustor assembly in Claim 24, wherein said fueling pathway has apertures located upstream of the axial midpoints of said vanes.

Claim 26

The combustor assembly in Claim 24, wherein said vanes have chords varying with radial distance from said centerbody.

Claim 27

The combustor assembly in Claim 24, wherein each of said vanes has an airfoil shape for minimizing flow separation and thereby preventing auto ignition combustion within said premix dome.

Claim 28

A combustor assembly comprising means for dispensing fuel into air immediately at the start of the assembly, means for thoroughly blending the flow of fuel and air gently without producing a shear layer in the flow, means for accelerating the flow of fuel and air downstream, and means for ejecting the accelerated flow into a combustor in a diffuse manner.

Claim 29

A combustor assembly for receiving a flow of fuel from an external source and a flow of air from a compressor, comprising: a combustion barrel having an inner surface, an upstream end and a downstream end; a premix dome having a downstream end connected to the upstream end of said combustion barrel for receiving and substantially premixing the fuel and air prior to delivery to said upstream end of said combustion housing; and a plurality of pilot fuel nozzles equally spaced adjacent said downstream end of said premix dome, each of said nozzles having a longitudinal axis oriented at about 15° with respect to said inner surface of said combustion barrel, each of said nozzles having a fuel exit hole opening into said upstream end of said combustion barrel and oriented at about 45° with respect to said inner surface of said combustion barrel; said premix dome further comprising: a centerbody extending longitudinally through said premix dome; a vaned swirler positioned around said centerbody for turning and mixing the fuel and air passing through said premix dome, said vaned swirler including a plurality of vanes, each of said vanes having a leading edge and a plurality of apertures formed adjacent said leading edge; a fueling pathway positioned radially along said swirler for delivering fuel across said swirler, said fueling pathway including a plurality of fuel passages formed in said vanes and in flow communication with said apertures of said vanes; and an annular premixing chamber located downstream said swirler, positioned around said centerbody and defining therebetween a cavity having a converging portion for accelerating the flow of fuel and air passing through said premix dome to said upstream end of said combustion barrel to inhibit flashback into said premix dome.

Claim 30

A gas turbine engine including a compressor section for supplying compressed air, a turbine section, a combustor section positioned operatively therebetween, and a means for supplying fuel to said combustor section, said combustor section comprising: a combustion housing having an upstream end and a downstream end; and a premix dome connected to said upstream end of said combustion housing for receiving and substantially premixing the fuel and air prior to delivery to said upstream end of said combustion housing, said premix dome comprising: a centerbody extending longitudinally through said premix dome; a vaned swirler having an inlet and an outlet, said vaned swirler positioned around said centerbody and turning the flow of fuel and air from said inlet to said outlet through an angle between about 60° and about 70°; and a fueling pathway connected to said means for supplying fuel for delivering fuel across said swirler.