STAGED BLADE INJECTOR

BACKGROUND

This disclosure relates to a gas turbine engine, and more particularly to staged blade injector that may be incorporated into a gas turbine engine.

Gas turbine engines typically include a compressor section, a combustor section and a turbine section. During operation, air is pressurized in the compressor section and is mixed with fuel and burned in the combustor section to generate hot combustion gases. The hot combustion gases are communicated through the turbine section, which extracts energy from the hot combustion gases to power the compressor section and other gas turbine engine loads.

A plurality of devices are used to premix fuel and air downstream of a combustor head-end/dome (on/from the liner walls) of the gas turbine engine to allow for axial or aft staging of the combustion process. The plurality of devices need to be configured in order to provide for a “lean” combustion process and reduce NOx emissions.

BRIEF DESCRIPTION

Disclosed is a blade fuel injector for a gas turbine engine, including: a mixer, the mixer having a first set of openings located on opposite sides of the mixer and a second set of openings located below the first set of openings; and a blade injector, the blade injector having a plurality of atomizers, wherein some of the first set of openings align with the plurality of atomizers.

In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the first set of openings is a pair of opposing elongated openings.

In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the blade injector is removably installed into the mixer.

In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the blade injector and mixer are formed as a single unitary unit wherein the blade injector is not removable from the mixer.

In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the second set of openings are located on opposite sides of the mixer.

In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the second set of openings are of varying sizes.

In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, some of the second set of openings are elliptical in shape.

In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the first set of openings is a pair of opposing elongated openings.

In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the second set of openings are of varying sizes and are teardrop in shape or elliptical in shape.

In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the second set of openings that are teardrop in shape are located in an alternating pattern with respect to the second set of openings that are elliptical in shape.

Also disclosed is a combustor for a gas turbine engine, including: a plurality of pilot fuel injectors; a plurality of blade fuel injectors, each blade fuel injector including: a mixer, the mixer having a first set of openings located on opposite sides of the mixer and a second set of openings located below the first set of openings; and a blade injector, the blade injector having a plurality of atomizers, wherein some of the first set of openings align with the plurality of atomizers.

In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the plurality of pilot fuel injectors inject fuel in a combustion chamber of the combustor in a first direction and the plurality of blade fuel injectors inject fuel into the combustion chamber is a second direction which is different from the first direction.

In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the first direction is generally or substantially aligned with an axis of the gas turbine engine and the second direction is substantially orthogonal or perpendicular to the first direction.

In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the combustor is an annular combustor.

In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the plurality of blade fuel injectors are located at a 45 degree angle with respect to a forward end of the combustor.

In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the mixer is located in an annular outer plenum and extends from an outer case to an outer wall of the combustion chamber and the mixer provides a path for air and fuel to the combustion chamber and the mixer provides a path from the annular outer plenum to the combustion chamber.

In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the first set of openings is a pair of opposing elongated openings.

In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the blade injector is removably installed into the mixer.

In addition to one or more of the features described above, or as an alternative to any of the foregoing embodiments, the second set of openings are located on opposite sides of the mixer.

BRIEF DESCRIPTION OF THE DRAWINGS

The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:

FIG. 1 is a schematic, partial cross-sectional view of a gas turbine engine in accordance with this disclosure;

FIG. 2A is a perspective view of a combustor in accordance with the present disclosure;

FIG. 2B is a side view of a combustor in accordance with the present disclosure;

FIG. 2C is an end view of a combustor in accordance with the present disclosure;

FIG. 3 is a partial cross-sectional view of a portion of a combustor in accordance with the present disclosure;

FIG. 4 is a partial perspective cross-sectional view of a portion of a combustor in accordance with the present disclosure;

FIG. 5 is a partial perspective cross-sectional view of a portion of a blade injector and mixer of a fuel injector in accordance with an embodiment of the present disclosure;

FIG. 6 is a partial perspective cross-sectional view of a portion of a blade injector and mixer of a fuel injector in accordance with an embodiment of the present disclosure;

FIG. 7 is a cross-sectional view of a portion of a blade injector and mixer of a fuel injector in accordance with an embodiment of the present disclosure;

FIG. 8 is a cross-sectional view of a portion of a blade injector and mixer along lines 8-8 in FIG. 7;

FIG. 9 is a cross-sectional view of a portion of a blade injector and mixer along lines 9-9 in FIG. 7;

FIGS. 10A and 10B are partial perspective cross-sectional views of a portion of a blade injector and mixer of a fuel injector in accordance with an embodiment of the present disclosure;

FIG. 11 is an end view looking into the mixer from a bottom of the mixer in accordance with an embodiment of the present disclosure;

FIG. 12 is a view along lines 12-12 of FIG. 11; and

FIGS. 13A-13E are views of a blade injector and mixer of a fuel injector in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION

A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the FIGS.

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.

FIG. 1 schematically illustrates a gas turbine engine 20. The gas turbine engine 20 is disclosed herein as a two-spool turbofan that generally incorporates a fan section 22, a compressor section 24, a combustor section 26 and a turbine section 28. Alternative engines might include other systems or features. The fan section 22 drives air along a bypass flow path B in a bypass duct, while the compressor section 24 drives air along a core flow path C for compression and communication into the combustor section 26 then expansion through the turbine section 28. Although depicted as a two-spool turbofan gas turbine engine in the disclosed non-limiting embodiment, it should be understood that the concepts described herein are not limited to use with two-spool turbofans as the teachings may be applied to other types of turbine engines including three-spool architectures.

The exemplary engine 20 generally includes a low speed spool 30 and a high speed spool 32 mounted for rotation about an engine central longitudinal axis A relative to an engine static structure 36 via several bearing systems 38. It should be understood that various bearing systems 38 at various locations may alternatively or additionally be provided, and the location of bearing systems 38 may be varied as appropriate to the application.

The low speed spool 30 generally includes an inner shaft 40 that interconnects a fan 42, a first or low pressure compressor 44 and a first or low pressure turbine 46. The inner shaft 40 is connected to the fan 42 through a speed change mechanism, which in exemplary gas turbine engine 20 is illustrated as a geared architecture 48 to drive the fan 42 at a lower speed than the low speed spool 30. The high speed spool 32 includes an outer shaft 50 that interconnects a second or high pressure compressor 52 and a second or high pressure turbine 54. A combustor 56 is arranged in exemplary gas turbine 20 between the high pressure compressor 52 and the high pressure turbine 54. A mid-turbine frame 57 of the engine static structure 36 is arranged generally between the high pressure turbine 54 and the low pressure turbine 46. The mid-turbine frame 57 further supports bearing systems 38 in the turbine section 28. The inner shaft 40 and the outer shaft 50 are concentric and rotate via bearing systems 38 about the engine central longitudinal axis A which is collinear with their longitudinal axes.

The core airflow is compressed by the low pressure compressor 44 then the high pressure compressor 52, mixed and burned with fuel in the combustor 56, then expanded over the high pressure turbine 54 and low pressure turbine 46. The mid-turbine frame 57 includes airfoils 59 which are in the core airflow path C. The turbines 46, 54 rotationally drive the respective low speed spool 30 and high speed spool 32 in response to the expansion. It will be appreciated that each of the positions of the fan section 22, compressor section 24, combustor section 26, turbine section 28, and fan drive gear system 48 may be varied. For example, gear system 48 may be located aft of combustor section 26 or even aft of turbine section 28, and fan section 22 may be positioned forward or aft of the location of gear system 48.

The engine 20 in one example is a high-bypass geared aircraft engine. It should be understood, however, that the above parameters are only exemplary of one embodiment of a geared architecture engine and that the present disclosure is applicable to other gas turbine engines including direct drive turbofans.

Referring now to at least FIGS. 2A-4, a combustor 56 in accordance with the present disclosure is illustrated. The combustor 56 may be referred to as an annular combustor 56. FIG. 2A is a perspective view of the combustor 56 while FIG. 2B is a side view of the combustor and the FIG. 2C is an end view of the combustor 56. The combustor 56 has an outer case or combustor-diffuser case 70 of the engine 20. Disposed about the outer periphery of the outer case or combustor-diffuser case 70 are a plurality of pilot fuel injectors 72 and a plurality of main fuel injectors 74.

The combustor 56 has an outer wall 76, an inner wall 78 and a diffuser case module 80. The outer wall 76 and the inner wall 78 are spaced apart radially with respect to axis A and such that a combustion chamber 82 is generally defined therebetween. The combustion chamber 82 is generally annular in shape. The outer wall 76 is spaced radially inward from the outer case or combustor-diffuser case 70 of the diffuser case module 80, with an annular outer plenum 84 being defined therebetween. The inner wall 78 is spaced radially outward from a diffuser inner case 86 of the diffuser case module 80 to define an annular inner plenum 88. It should be understood that although a particular combustor is illustrated, other combustor types with various combustor wall and case arrangements will also benefit here from. For instance, the diffuser outer case 70 maybe an integral part of an engine case structure.

Furthermore, although shown and described with respect to an aircraft engine, those of skill in the art will appreciate that embodiments provided herein can be employed within land-based or sea-based gas turbine engines and/or so industrial gas turbines (IGT). Furthermore, combustors as provided herein can be annular combustors, can combustors, or other types of combustors as known in the art. Further, in some embodiments, such as in industrial gas turbines, as known, water may be injected into the combustion chamber and used for emission control. Such water and/or associated water supply can be used as a cooling source.

Each combustor wall 76, 78 generally includes a respective support shell 90, 92, respectively, that supports one or more liners 94, 96, respectively, mounted to a hot side of the respective support shell 90, 92. The liners 94, 96 directly define the combustion chamber 80 that contains the flow of combustion products for driving the turbine section 28. The liners 94, 96 can be comprised of a plurality of Impingement Film Float (IFF) panels orientated in a generally rectilinear liner array. Each panel can be manufactured of, for example, a nickel based super alloy, ceramic, or other temperature resistant material. In non-limiting embodiments, the array of panels of the liners can include a plurality of forward liner panels and a plurality of aft liner panels that line the hot side of the outer shell 90 and a plurality of forward liner panels and a plurality of aft liner panels that line the hot side of the inner shell 92.

The combustor 56 also includes a forward assembly 98 immediately downstream of the compressor section 24 to guide compressed airflow C therefrom. The forward assembly 98 generally includes an annular wall or bulkhead support shell 100 of a bulkhead assembly 102, and a plurality of swirlers 104 spaced circumferentially about engine axis A.

The annular wall 100 extends radially between, and in one non-limiting embodiment is secured to the forward most ends of the walls 76, 78 and in particular may be secured to outer and inner walls 90, 92. A plurality of circumferentially ports in annular wall 100 each accommodate a respective one of the plurality of pilot fuel injectors 72 as well as direct compressed air C into the forward end of the combustion chamber 82 through the associated swirler 104. Each pilot fuel injector 72, can be secured to the diffuser case module 80 to project through one of the ports and the respective swirler 104. It should be appreciated that various architectures of the forward assembly 98 can also benefit herefrom.

Each swirler 104, is circumferentially aligned with a respective port to project through the bulkhead assembly 102. The bulkhead assembly 102 includes a plurality of circumferentially distributed bulkhead heat shields 106 secured to the annular wall or bulkhead support shell 100 around each swirler 104.

The forward assembly 98 and walls 76 and 78 are configured to introduce core combustion air C into the forward end of the combustion chamber 82 while the remainder enters from the annular outer plenum 84 and the annular inner plenum 88. The plurality of pilot injectors 72 and respective swirlers 104 facilitate the generation of a blended fuel-air mixture that supports combustion in the combustion chamber 82. Thereafter, the combusted gases travel through an exit 83 of the combustor towards the turbine section 28 of the engine 20. An igniter is provided to start and enable combustion within the combustion chamber 82.

As illustrated, the combustor 56 is configured with a plurality of axially staged main fuel injectors 74. The main fuel injectors 74 may be referred to blade injectors 74 and include swirlers or mixers 108. The pilot fuel injectors 72 inject fuel in a first direction which may be generally or substantially aligned axis A or in one embodiment parallel to axis A while the main fuel injectors 74 inject fuel into the combustion chamber 82 is a second direction that is in one non-limiting embodiment substantially orthogonal or perpendicular to the first direction or different from the first direction. In some embodiments, the main fuel injectors 74 can be oriented with an angle with respect to the pilot fuel injector(s) 72. Those of skill in the art will appreciate that main fuel injectors 74 can be positioned above and/or below the combustion chamber 82 such that fuel can be injected from either or both the inner diameter or the outer diameter of the combustion chamber 82.

As provided in accordance with embodiments of the present disclosure, lean-staging can be achieved by axially distributing the fuel injection with front-end pilot injectors 72 and downstream main injectors 74 to axially distribute the heat release similar to a Rich Quench Lean design, as known in the art. However, embodiments provided herein have lean/lean combustion to enable low NOx and particulate emissions. Such configuration is different from radial staged designs where all the fuel is injected at the front-end of the combustor.

In accordance with the present disclosure, the pilot and main injector(s) can each include measures to control the combustion dynamics and/or combustion instabilities within various zones of the combustion chamber. For example dynamics can be controlled or measured within an injector that is based on a high shear design with dual secondary fuel injection locations, with dynamic control for upstream injection for improved high power emissions and downstream injection for low power tone mitigation.

In accordance with the present disclosure, the main injectors 74 are blade injectors that include swirlers, mixers or blade mixer 108. In one non-limiting embodiment, the mixers 108 can be located at a 45 degree angle with respect to a forward end of the combustor 56 or the pilot injectors 72. For example, a broad side of the main injectors 74 opposes the pilot injectors 72.

As such, the “blade” mixer 108 can be rotated/angled relative to the combustor's axis to augment/affect the interaction between the main reactants with the pilot's products in the combustor. The angling or rotation can also affect the combustor's exit temperature profile and pattern factor.

In one non-limiting embodiment, the blade mixer 108 is located in the annular outer plenum 84 and extends from the outer case or combustor-diffuser case 70 to the outer wall 76. The blade mixer 108 provides a path for air and fuel to the combustion chamber 82. In particular, the blade mixer 108 will provide a path from the annular outer plenum 84 to the combustion chamber 82.

As such, the mixer 108 and injector 74 directs a portion of the combustion air from the annulus 84 between the combustor liner 94 and engine case 70 into the mixer 108, where it mixes with fuel in preparation to combust in the combustion chamber 82 of the combustor 56 aft and downstream of the combustor's front end. The mixer 108 uses a portion of the available combustor pressure drop to create specifically shaped and oriented air jets that airblast atomize the liquid fuel and that drive turbulence and circulation within the mixer 108 to premix the fuel and air. The mixer 108 delivers better than 50% fuel-air mixedness (or coefficient of variation), within a short residence time and mixing distance, prior to combustion—making autoignition or flashback improbable (e.g., less than 1% chance) within the device. Also, the device can have multiple fuel injection circuits independently feeding injectors spaced along the length of the device to vary the fuel-air-ratio along the length of the device's exit as a function of % engine power or atmospheric conditions.

As such, the present disclosure premixes more than 30% of the combustor's fuel and air aft (downstream) of the front-end (dome) primary zone. The present disclosure also manages the airflow and fuel flow in a very confined space. As such, it allows for the staging of fuel via multiple fuel injection points to match the cycle requirements. It uses a reasonable pressure drop.

The present disclosure also can be incorporated into low-emissions gas-turbine combustors, where the focus is on reducing emissions (e.g., NOx, CO, and PM) while maintaining or improving performance and durability.

Referring now to at least FIG. 5 is a partial perspective cross-sectional view of a portion of a blade injector 110 and mixer 108 of a main fuel injector 74 in accordance with an embodiment of the present disclosure is illustrated. The blade injector 110 can be removably installed into the mixer 108 of the main fuel injector 74 or it and the mixer 108 are formed as a single unitary unit where one is not removable from the other.

The blade injector 110 will have a plurality of atomizers 112 which can be anyone of a fan spray atomizer, pressure swirler atomizer, plane jet atomizer or any suitable equivalent. The plurality of atomizers 112 may be on both sides of the blade injector or only one side. In addition the atomizers located on opposite sides of the blade injector may be aligned with each other or offset from each other. Each atomizer can be run independently via multiple fuel circuits or ganged with others using a single fuel circuit.

As illustrated in at least FIGS. 5-9, the mixer 108 has a pair of elongated openings 114 located on opposite sides of the mixer 108 that align with the atomizers 112. The elongated openings 114 may be a continuous slot. Alternatively, the elongated openings or continuous slots 114 may be replaced with a plurality of openings 116 of varying sizes (e.g., discrete windows of various shapes (e.g., triangles, circles, etc.) located on opposite sides of the mixer 108. Alternatively, one side may have a continuous slot 114 and the other a plurality of openings 116 or both sides may have the continuous slot 114.

Located below, the elongated openings or continuous slots 114 or plurality of openings 116 of varying sizes are a second set of openings 118 which may be teardrop in shape or elliptical in shape. As illustrated, the teardrop shapes of the second set of openings 118 may be located in an alternating pattern with respect to the elliptical shaped openings 118.

As illustrated by arrow 120, the fuel jet is airblasted by incoming air flow (approximately 40% of the mixer's airflow).

As illustrated by arrow 122, any fuel on the concave blade surface will be airblasted off the downstream edge by the opposing opening 114 (approximately 20% of the mixer's airflow).

As illustrated, by arrows 124, the initial airblasted, dispersed fuel will be turbulently mixed by the pattern of shaped (teardrops and ellipses shown) of the second set of openings 118, opposing the mixing jets or atomizers 112 of the injector 74 (approximately 40% of the mixer's airflow) before exiting the mixer 108 into the combustor 56.

In this embodiment, the larger teardrop holes on opposing sides straddle each fuel jet or atomizer 112 and the smaller elliptical holes of the second set of openings 118 are inline with the opposing, larger tear drop holes of the second set of openings 118.

FIG. 6 is a partial perspective cross-sectional view of a portion of a blade injector 110 and the mixer 108 in accordance with an embodiment of the present disclosure.

FIG. 7 is a cross-sectional view of a portion of the blade injector 110 and mixer 108 in accordance with an embodiment of the present disclosure.

FIG. 8 is a cross-sectional view of a portion of the blade injector 110 and mixer 108 along lines 8-8 in FIG. 7. Lines 8-8 are in line with the fuel injection 112 plane.

FIG. 9 is a cross-sectional view of a portion of the blade injector 110 and mixer 108 along lines 9-9 in FIG. 7. Lines 9-9 are located between the fuel injection planes.

As illustrated herein, the “Blade” fuel injector 110 is aerodynamically contoured with the first 114 and second inlet passages 118. As mentioned above, it can be integrated with the mixer 108, as a single assembly, or it can be a separate part that slides into the mixer 108 (as shown).

FIGS. 10A and 10B are partial perspective cross-sectional views of a portion of a blade injector 110 and mixer 108 in accordance with another embodiment of the present disclosure. Here the mixer 108 has first inlet passages 114 which may be a continuous slot or may be replaced with a plurality of openings 116 of varying sizes (e.g., discrete windows of various shapes (e.g., triangles, circles, etc.). As mentioned above, the elongated openings or continuous slots 114 may be replaced with a plurality of openings 116 of varying sizes (e.g., discrete windows of various shapes (e.g., triangles, circles, etc.) located on opposite sides of the mixer 108. Alternatively, one side may have a continuous slot 114 and the other a plurality of openings 116 or both sides may have the continuous slot 114.

FIG. 11 is an end view looking into the mixer from a bottom of the mixer in accordance with the embodiment illustrated in at least FIGS. 10A and 10B of the present disclosure and FIG. 12 is a view along lines 12-12 of FIG. 11.

However and in this embodiment, the function of the second inlet passages 118 is replaced by a plurality of vortex generators 120 located on an interior surface of the mixer 108 below the first inlet passages 114.

FIGS. 13A-13E are views of a blade injector 110 and mixer 108 in accordance with another embodiment of the present disclosure. Here the fuel injector 110 is integrated with the mixer 108 as a single component. Also, shown in FIGS. 13A-13E, the elongated openings or continuous slots 114 are replaced with the plurality of openings 116 of varying sizes (e.g., discrete windows of various shapes (e.g., triangles, circles, etc.) located on opposite sides of the mixer 108.

In addition, the injection points 112 alternate back and forth from side to side.

The term “about” is intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application. For example, “about” can include a range of +8% or 5%, or 2% of a given value.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. 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, element components, and/or groups thereof.

While the present disclosure has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this present disclosure, but that the present disclosure will include all embodiments falling within the scope of the claims.

STAGED BLADE INJECTOR

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