Patent Application
20170268780
The present invention generally involves a bundled tube fuel nozzle for a gas turbine combustor. More specifically, the invention relates to a bundled tube fuel nozzle with vibration damping.
Particular combustion systems for gas turbine engines utilize combustors having bundled tube type fuel nozzles for premixing a gaseous fuel with a compressed air upstream from a combustion zone. A bundled tube fuel nozzle generally includes multiple tubes that extend through a fuel plenum which is at least partially defined between a forward plate, an intermediate plate and an outer sleeve. Compressed air flows into an inlet portion of each tube. Fuel from the fuel plenum is injected into each tube where it premixes with the compressed before it is routed into the combustion zone.
A portion of each tube may be rigidly connected to the intermediate plate while a downstream end or tip portion is unsupported, thereby creating a cantilevered tube. The downstream end or tip portion of each tube extends through a corresponding tube opening defined in an aft plate which is axially spaced from the intermediate plate and positioned proximate to the combustion chamber. A circumferentially continuous radial gap is defined between an outer surface of each tube at its tip portion and the corresponding tube opening in the aft plate to allow for a cooling fluid such as compressed air to flow around the tube towards the combustion chamber, thereby cooling the tip portion. During operation, the tip portion of each tube may vibrate causing potentially resulting in undesirable wear between the individual tubes and the aft plate.
Aspects and advantages are set forth below in the following description, or may be obvious from the description, or may be learned through practice.
One embodiment of the present disclosure is a bundled tube fuel nozzle. The bundled tube fuel nozzle includes a forward plate, an intermediate plate, an aft plate and an outer sleeve. The forward plate, the intermediate plate and the outer sleeve define a fuel plenum therebetween. An aft plate is axially spaced from the intermediate plate and the intermediate plate, the aft plate and the outer sleeve define a cooling air plenum therebetween. A plurality of tubes extends through the forward plate, the fuel plenum, the intermediate plate, the cooling air plenum and the aft plate. Each tube of the plurality of tubes extends through a respective tube opening of a plurality of tube openings defined by the aft plate. A radial gap is defined between an outer surface of each tube and an inner surface of the respective tube opening. The plurality of tubes comprises at least one tube that is radially loaded against the inner surface of the respective tube opening.
Another embodiment of the present disclosure is a combustor. The combustor includes an end cover coupled to an outer casing and a bundled tube fuel nozzle disposed within the outer casing and coupled to the end cover via one or more fluid conduits. The bundled tube fuel nozzle includes a forward plate, an intermediate plate, an aft plate and an outer sleeve. The forward plate, the intermediate plate and the outer sleeve define a fuel plenum therebetween. An aft plate is axially spaced from the intermediate plate and the intermediate plate, the aft plate and the outer sleeve define a cooling air plenum therebetween. A plurality of tubes extends through the forward plate, the fuel plenum, the intermediate plate, the cooling air plenum and the aft plate. Each tube of the plurality of tubes extends through a respective tube opening of a plurality of tube openings defined by the aft plate. A radial gap is defined between an outer surface of each tube and an inner surface of the respective tube opening. The plurality of tubes comprises at least one tube that is radially loaded against the inner surface of the respective tube opening.
Another embodiment includes a gas turbine. The gas turbine includes a compressor, a combustor downstream from the compressor and a turbine disposed downstream form the compressor. The combustor includes an end cover that is coupled to an outer casing and a bundled tube fuel nozzle disposed within the outer casing and coupled to the end cover via one or more fluid conduits. The bundled tube fuel nozzle includes a forward plate, an intermediate plate, an aft plate and an outer sleeve. The forward plate, the intermediate plate and the outer sleeve define a fuel plenum therebetween. An aft plate is axially spaced from the intermediate plate and the intermediate plate, the aft plate and the outer sleeve define a cooling air plenum therebetween. A plurality of tubes extends through the forward plate, the fuel plenum, the intermediate plate, the cooling air plenum and the aft plate. Each tube of the plurality of tubes extends through a respective tube opening of a plurality of tube openings defined by the aft plate. A radial gap is defined between an outer surface of each tube and an inner surface of the respective tube opening. The plurality of tubes comprises at least one tube that is radially loaded against the inner surface of the respective tube opening.
Those of ordinary skill in the art will better appreciate the features and aspects of such embodiments, and others, upon review of the specification.
A full and enabling disclosure of the of various embodiments, including the best mode thereof to one skilled in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying figures, in which:
Reference will now be made in detail to present embodiments of the disclosure, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and letter designations to refer to features in the drawings. Like or similar designations in the drawings and description have been used to refer to like or similar parts of the disclosure.
As used herein, the terms “first”, “second”, and “third” may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components. The terms “upstream” and “downstream” refer to the relative direction with respect to fluid flow in a fluid pathway. For example, “upstream” refers to the direction from which the fluid flows, and “downstream” refers to the direction to which the fluid flows. The term “radially” refers to the relative direction that is substantially perpendicular to an axial centerline of a particular component, and the term “axially” refers to the relative direction that is substantially parallel and/or coaxially aligned to an axial centerline of a particular component.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
Each example is provided by way of explanation, not limitation. In fact, it will be apparent to those skilled in the art that modifications and variations can be made without departing from the scope or spirit thereof. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present disclosure covers such modifications and variations as come within the scope of the appended claims and their equivalents. Although exemplary embodiments of the present disclosure will be described generally in the context of a bundled tube fuel nozzle for a land based power generating gas turbine combustor for purposes of illustration, one of ordinary skill in the art will readily appreciate that embodiments of the present disclosure may be applied to any style or type of combustor for a turbomachine and are not limited to combustors or combustion systems for land based power generating gas turbines unless specifically recited in the claims.
Referring now to the drawings,
During operation, air 24 flows through the inlet section 12 and into the compressor 14 where the air 24 is progressively compressed, thus providing compressed air 26 to the combustor 16. At least a portion of the compressed air 26 is mixed with a fuel 28 within the combustor 16 and burned to produce combustion gases 30. The combustion gases 30 flow from the combustor 16 into the turbine 18, wherein energy (kinetic and/or thermal) is transferred from the combustion gases 30 to rotor blades (not shown), thus causing shaft 22 to rotate. The mechanical rotational energy may then be used for various purposes such as to power the compressor 14 and/or to generate electricity. The combustion gases 30 exiting the turbine 18 may then be exhausted from the gas turbine 10 via the exhaust section 20.
As shown in
In particular embodiments, the head end portion 38 is in fluid communication with the high pressure plenum 34 and/or the compressor 14. One or more liners or ducts 40 may at least partially define a combustion chamber or zone 42 for combusting the fuel-air mixture and/or may at least partially define a hot gas path through the combustor as indicated by arrow 44, for directing the combustion gases 30 towards an inlet to the turbine 18.
In various embodiments, the combustor 16 includes at least one bundled tube fuel nozzle 100. As shown in
In at least one embodiment, as shown in
In various embodiments, as shown in
During operation, in the known configuration as shown in
The tube(s) 120, particularly the tip portion(s) 130, may have circular or non-circular cross sectional shapes. For example, the tube(s) 120 may be circular, oval, triangular or multisided such as a pentagon, hexagon, octagon or any other non-circular shape which allows for at least one contact point CP between the outer surface 136 of the tube(s) 120 and the inner surface 138 of the respective tube opening 132.
In particular embodiments, as shown in
The various embodiments illustrated and described herein provide various technical benefits over exiting bundled tube fuel nozzles. For example, the radial loaded tubes reduce tube tip wear thus improving tube life. In addition, the embodiments provided do not require an increase in part count which saves manufacturing costs and time and may reduce high cycle fatigue at the tube/intermediate plate connection.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
