The present invention generally involves a combustor such as may be incorporated into a gas turbine or other turbo-machine. Specifically, the invention relates to a combustor having a system for supporting a bundled tube fuel injector within the combustor.
Combustors are commonly used in industrial and power generation operations to ignite fuel to produce combustion gases having a high temperature and pressure. For example, turbo-machines such as gas turbines typically include one or more combustors to generate power or thrust. A typical gas turbine includes an inlet section, a compressor section, a combustion section, a turbine section, and an exhaust section. The inlet section cleans and conditions a working fluid (e.g., air) and supplies the working fluid to the compressor section. The compressor section progressively increases the pressure of the working fluid and supplies a compressed working fluid to the combustion section. A fuel is mixed with the compressed working fluid within the combustion section and the mixture is burned in a combustion chamber defined within the combustion section to generate combustion gases having a high temperature and pressure. The combustion gases flow to the turbine section where they expand to produce work. For example, expansion of the combustion gases in the turbine section may rotate a shaft connected to a generator to produce electricity.
The combustion section may include one or more combustors annularly arranged between the compressor section and the turbine section. In a particular combustor design, the combustors include one or more axially extending bundled tube fuel injectors disposed downstream from an end cover. The end cover generally includes one or more fuel circuits that provide fuel to a fluid conduit that provides for fluid communication between the fuel circuits and a fuel plenum defined within each bundled tube fuel injector. Each bundled tube fuel injector generally includes a plurality of parallel tubes arranged radially and circumferentially across the bundled tube fuel injector. The parallel tubes extend generally axially through the fuel plenum to provide for fluid communication through the fuel plenum and into the combustion chamber. The compressed working fluid is routed through inlets of each of the parallel tubes. Fuel is supplied to the fuel plenum through the fluid conduit and the fuel is injected into the tubes through one or more fuel ports defined within each of the tubes. The fuel and compressed working fluid mix inside the tubes before flowing out of the tubes and into the combustion chamber for combustion.
Typically, one end of the fluid conduit is rigidly bolted to the end cover and a second end is fixedly or rigidly connected to the bundled tube fuel injector, thereby creating an end loaded cantilevered mass. As a result, the fluid conduit generally carries the majority of the load created by the cantilevered bundled tube fuel injector at the end cover and fluid conduit connection.
The bundled tube fuel injector is typically heavier or has a greater mass than a conventional fuel nozzle structure which may also be cantilevered. As the combustor cycles through various operating modes, the cantilevered bundled tube fuel injector may vibrate at various frequencies which may result in large deflections of the fluid conduit, thereby causing undesirable bending stresses at the end cover and fluid conduit connection. Therefore, an improved system for mounting and/or supporting a bundled tube fuel injector within a combustor would be useful.
Aspects and advantages of the invention are set forth below in the following description, or may be obvious from the description, or may be learned through practice of the invention.
One embodiment of the present invention is a combustor. The combustor includes an end cover that is disposed at one end of the combustor. The end cover includes an outer side and an inner side. The combustor further includes an outer barrel having a forward end that is adjacent to the inner side of the end cover and an aft end that is axially spaced from the forward end. An inner barrel is at least partially disposed concentrically within the outer barrel and is fixedly connected to the outer barrel. A fluid conduit extends downstream from the end cover. A first bundled tube fuel injector segment is disposed concentrically within the inner barrel. The bundled tube fuel injector segment includes a fuel plenum that is in fluid communication with the fluid conduit and a plurality of parallel tubes that extend axially through the fuel plenum. The bundled tube fuel injector segment is fixedly connected to the inner barrel.
Another embodiment of the present invention is a combustor. The combustor includes an end cover that is disposed at one end of the combustor. The end cover at least partially defines a fuel feed passage that extends axially therethrough. An outer barrel extends axially away from the end cover within the combustor. An inner barrel extends within the outer barrel and is fixedly connected to the outer barrel. A bundled tube fuel injector segment is disposed concentrically within the inner barrel. The bundled tube fuel injector segment includes a fuel plenum and a plurality of parallel tubes that extend axially through the fuel plenum. The bundled tube fuel injector segment is fixedly connected to the inner barrel. The combustor further includes a fluid conduit that provides for fluid communication between the fuel feed passage and the fuel plenum. The fluid conduit includes a first portion that extends within the fuel feed passage and a second portion that is fixedly connected to the bundled tube fuel injector segment. The first portion is slidable within the fuel feed passage to allow for thermal growth of the fluid conduit.
The present invention may also include a gas turbine. The gas turbine includes a compressor, a combustor that is at least partially surrounded by an outer casing disposed downstream from the compressor and a turbine that is disposed downstream from the combustor. The combustor comprises an end cover that is coupled to the outer casing and that includes an outer side, an inner side and a fuel feed passage that extends through the outer and the inner sides. A center fuel nozzle extends downstream from the inner side. An outer barrel extends axially away from the end cover within the combustor. An inner barrel extends within the outer barrel and at least partially surrounds the center fuel nozzle. The inner barrel is fixedly connected to the outer barrel. A bundled tube fuel injector segment is disposed between the center fuel nozzle and the inner barrel. The bundled tube fuel injector segment includes a fuel plenum and a plurality of parallel tubes that extend axially through the fuel plenum. The bundled tube fuel injector segment is fixedly connected to the inner barrel. The combustor further includes a fluid conduit that provides for fluid communication between the fuel feed passage and the fuel plenum. The fluid conduit includes a first portion that extends within the fuel feed passage and a second portion that is fixedly connected to the bundled tube fuel injector segment. The first portion is slidable within the fuel feed passage to allow for thermal growth of the fluid conduit.
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 present invention, 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 invention, 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 invention. 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 to an axial centerline of a particular component.
Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present invention 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 invention covers such modifications and variations as come within the scope of the appended claims and their equivalents. Although exemplary embodiments of the present invention will be described generally in the context of a combustor incorporated into a gas turbine for purposes of illustration, one of ordinary skill in the art will readily appreciate that embodiments of the present invention may be applied to any combustor incorporated into any turbo-machine and are not limited to a gas turbine combustor unless specifically recited in the claims.
Referring now to the drawings, wherein identical numerals indicate the same elements throughout the figures,
The combustion gases 24 flow through a turbine 26 where thermal and kinetic energy are transferred to one or more stages of turbine rotor blades (not shown) that are connected to a rotor shaft 28, thereby causing the rotor shaft 28 to rotate to produce work. For example, the rotor shaft 28 may be used to drive the compressor 16 to produce the compressed working fluid 18. Alternately or in addition, the rotor shaft 28 may connect the turbine 26 to a generator 30 for producing electricity. Exhaust gases 32 from the turbine 26 flow through an exhaust section 34 that may connect the turbine 26 to an exhaust stack 36 downstream from the turbine 26. The exhaust section 34 may include, for example, a heat recovery steam generator (not shown) for cleaning and extracting additional heat from the exhaust gases 32 prior to release to the environment.
The combustors 20 may be any type of combustor known in the art, and the present invention is not limited to any particular combustor design unless specifically recited in the claims.
The compressed working fluid 18 is routed to the end cover 42 where it reverses direction and flows through one or more bundled tube fuel injectors 52 disposed downstream from the end cover 42. Fuel is provided to the bundled tube fuel injector 52 and the fuel and the compressed working fluid are premixed or combined within the bundled tube fuel injectors 52 before being injected into a combustion chamber 54 defined within the combustor 20. The fuel and compressed working fluid mixture is burned in the combustion chamber 54 to generate the hot combustion gases 24.
In particular embodiments, the combustor 20 includes an outer barrel 68. The outer barrel 68 is generally cylindrically shaped. The outer barrel 68 includes a forward end 70 and an aft end 72. In particular embodiments, the forward end 70 is generally adjacent to the inner side 58 of the end cover 42. The aft end 72 is axially spaced from the forward end 70 with respect to the axial centerline 60. In particular embodiments, the outer barrel 68 is coaxially aligned with respect to the axial centerline 60 of the end cover 42. The outer barrel 68 may at least partially define a head end plenum 74 of the combustor 20. In particular embodiments, the forward end 70 is fixedly connected to the end cover 42. For example, the forward end 70 of the outer barrel 68 may be pinned, bolted, welded, brazed or otherwise fixedly connected to the end cover 42. In addition or in the alternative, as shown in
In particular embodiments, the combustor 20 includes an inner barrel 78. The inner barrel 78 may be generally cylindrically shaped. At least a portion of the inner barrel 78 is disposed within the outer barrel 68. The inner barrel 78 includes a forward end 80 that is proximate to the end cover 42 and an aft end 82 that is axially separated from the forward end 80. In particular embodiments, the inner barrel 78 is coaxially aligned with the outer barrel 68. In one embodiment, the inner barrel 78 extends concentrically within the outer barrel 68. The inner barrel 78 and the outer barrel 68 are spaced radially apart so as to define a flow passage 84 therebetween.
In particular embodiments, the inner barrel 78 is fixedly connected to the outer barrel 68. For example, the inner barrel 78 may be pinned, bolted, welded, brazed or otherwise fixedly connected to the outer barrel 68. In particular embodiments, one or more struts 86 extend between the inner barrel 78 and the outer barrel 68 within the flow passage 84. In particular embodiments, the inner barrel 78 is fixedly connected to the outer barrel via the one or more struts 86.
In particular embodiments, an inlet flow conditioner 94 extends radially and circumferentially across the inner barrel generally proximate to the forward end 80. In one configuration, the inlet flow conditioner 94 generally comprises of an annular plate 96 that includes a plurality of flow holes 98 to condition or control the flow of the compressed working fluid 18 (
As shown in
In particular embodiments, as shown in
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In particular embodiments, as shown in
In operation, as illustrated in various figures, fuel 22 is routed from one the fuel circuits 64 through the fuel port 66 and into the fuel passage 130 where it is routed to the fuel plenum 118. As the combustor 20 cycles through various thermal transients, the fluid conduit 128 will expand or contract axially due to thermal expansion. Because the second portion 138 of the fluid conduit 128 is fixedly connected to the bundled tube fuel injector segment 109 and the bundled tube fuel injector segment 52 is fixedly connected to the inner barrel 78, the slidable interface between the first portion 136 of the fluid conduit 128 and the fuel feed passage 62 will accommodate for the axial growth of the fluid conduit 128. The annular seals maintain a fluid seal between the forward portion 136 of the fluid conduit 128 and the fuel feed passage 62 and/or the insert 144 as the fluid conduit expands and contracts within the fuel feed passage 62.
In one embodiment, as shown in
In this configuration, at least one annular seal 140 of the one or more annular seals 140 extends radially between the first portion of the fluid conduit and the orifice sleeve 146. For example, one of the one or more annular seals 140 may extend between the outer tube 132 and the inner surface 142 of the fuel feed passage 62 and at least one of the one or more annular seals 140 may extend radially between the inner tube 134 and the orifice sleeve 146. The annular seals 140 maintain a fluid seal between the forward portion 136 of the fluid conduit 128 and the fuel feed passage 62 and/or the orifice sleeve 146 as the fluid conduit expands and contracts or translates axially within the fuel feed passage 62.
During operation of the combustor 20, as illustrated in the various figures presented herein, the temperature of the compressed working fluid 18 is generally much higher than the temperature of the fuel 22 entering the fuel plenum 118. As a result, thermal stresses may impact the durability of brazed or welded joints that are formed to provide a seal between the tubes 110 and the first and second plates 120, 122 and/or the outer sleeve 124. In addition, the rigid connection and the proximity between outer sleeves 124 of the bundled tube fuel injectors 52 and the inner barrel 78 may also contribute to thermal gradients which may also result in undesirable thermal stresses, between the outer sleeve 124 and the inner barrel 78.
The heated air flow path 160 allows for a portion of the compressed working fluid 18 or some other heating medium to be routed from the flow passage 84 or other source (not shown) across the bundled tube fuel injector segments 109, particularly the outer sleeve 124, thereby providing convective heating to the outer sleeve 154 and reducing undesirable thermal gradients between the components. The compressed working fluid 18 may then be routed into the center fuel nozzle 108 and/or into the head end plenum 74 to accommodate for any pressure loss created by the 180 degree turning of the compressed working fluid 18 that enters the head end plenum 74 from the flow passage 84. As a result, potential for flame holding at the center fuel nozzle 108 may also be reduced.
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.
This invention was made with Government support under Contract No. DE-FC26-05NT42643, awarded by the Department of Energy. The Government has certain rights in the invention.