JP6186132B2 - Annular premix pilot for fuel nozzle - Google Patents

Description

  The present invention relates generally to a gas turbine engine that burns hydrocarbon fuel mixed with air to drive a turbine blade to produce a hot gas stream that rotates a shaft attached to the blade, and more specifically. The invention relates to an engine fuel nozzle having a pilot nozzle that premixes fuel and air while reducing nitrogen oxides.

  Gas turbine engines are widely used to generate power for many applications. A conventional gas turbine engine includes a compressor, a combustor, and a turbine. In a typical gas turbine engine, the compressor supplies compressed air to the combustor. The air entering the combustor is mixed with fuel and burned. The combustion hot gas is exhausted from the combustor and flows into the blades of the turbine to rotate the shaft of the turbine connected to the blades. Part of that mechanical energy of the rotating shaft drives the compressor and / or other mechanical systems.

  Government regulations do not allow nitrogen oxides to be released into the atmosphere and require that nitrogen oxide production as a by-product of gas turbine engine operation be maintained below acceptable standards. One strategy to meet such regulations is to use a fully premixed mode of operation to reduce, for example, nitrogen oxides (generally labeled NOx) and carbon monoxide (CO) emissions from diffusion flame combustors. It is used to move to a combustor with lean fuel and air mixture. These combustors are well known in the art as dry low NOx (DLN), dry low emission (DLE), or lean premixed (LPM) combustion systems.

  Fuel / air mixing affects both the amount of nitrogen oxides produced in the hot gas of combustion in a gas turbine engine and the performance of the engine. Gas turbine engines may use one or more fuel nozzles that take in air and fuel to facilitate fuel / air mixing in the combustor. The fuel nozzle may be located at the head end of the combustor and may be configured to capture airflow and mix with fuel input. In general, each fuel nozzle may be supported internally by a central body located within the fuel nozzle, and a pilot may be attached to the downstream end of the central body. For example, as described in US Pat. No. 6,438,961, which is incorporated herein by reference in its entirety for all purposes, a so-called swozzle is attached to the exterior of the central body and positioned upstream of the pilot. Can be made. The swozzle has a curved stationary blade that extends radially from the central body across the annular flow path, and fuel is introduced into the annular flow path from the stationary blade, and an air flow that forms a vortex by the stationary blade of the swozzle. It is mixed.

US Patent Application Publication No. 2011/0252803

  Various parameters describing the combustion process of a gas turbine engine correlate with the production of nitrogen oxides. For example, the higher the gas temperature in the combustion reaction zone, the more nitrogen oxide is produced. One way to reduce these temperatures is by premixing the mixture and reducing the ratio of fuel to air to burn. As the ratio of burned fuel to air decreases, the amount of nitrogen oxides also decreases. However, the performance of the gas turbine engine is sacrificed. This is because as the ratio of fuel to air to be burned decreases, the tendency of the fuel nozzle flame to disappear increases, resulting in unstable operation of the gas turbine engine. Diffusion flame type pilots have been used to provide better flame stability in the combustor, which increases NOx.

  Aspects and advantages of the invention are described in the following description, or may be obvious from the description, or may be learned by practicing the invention.

  Theoretically, at any point in the combustion chamber, as the stoichiometric relationship between fuel and air combusting at a given combustion temperature is obtained, the production of nitrogen oxides as a by-product of combustion is minimized. It leads to restraining to. A combustion nozzle configured as described below allows a more uniform equivalence ratio to be achieved across the entire surface of the outer nozzle central body tip, resulting in a given combustion in the combustion chamber of the gas turbine engine. Such a theoretical condition in the desired stoichiometric relationship between fuel burning at temperature and air can be achieved more approximately. In addition, to overcome one of the disadvantages of diffusion flame type pilots, the premix pilot is also used as a pilot to stabilize the pilot flame to prevent NOx increase even at low air-fuel ratios. be able to.

  In one embodiment of the fuel nozzle including a premixing conduit configured with a concentric axis parallel to the burner tube axis to guide the air-fuel mixture axially from the premixing pilot nozzle, at least one beside each premixing conduit. There are two air jets, each of which is directed radially outward from the premixing conduit so that each air jet entrains a portion of the mixture and causes the mixture to exit radially outward from the premixing conduit. To form a more uniform mixture at the burn exit plane of the nozzle and to the combustion chamber of the gas turbine. The air jet is desirably disposed at the downstream end of an annular channel disposed radially outward of the premixing conduit.

  In another embodiment of the invention, each premixing conduit itself is constructed concentrically about a central longitudinal axis disposed at an acute angle with respect to the axis of the burner tube to allow the mixture to pass through the axis of the burner tube. The air is guided radially outward from the center to form a more uniform air-fuel mixture at the combustion outlet surface of the nozzle, and is led into the combustion chamber of the gas turbine.

  In another embodiment of the invention, the premixing conduits themselves each have a first leg arranged parallel to the axis of the burner tube and a second leg arranged at an acute angle with respect to the axis of the burner tube. Concentric with respect to the central longitudinal axis of the two directions, and the air-fuel mixture is guided radially outwardly about the axis of the burner tube to provide a more uniform air-fuel mixture at the combustion outlet surface of the nozzle. It is formed and guided into the combustion chamber of the gas turbine.

  Each premixing conduit itself is concentric about a central longitudinal axis arranged at an acute angle with respect to the axis of the burner tube to guide the mixture radially outwardly about the axis of the burner tube In a further embodiment, there is at least one air jet next to each premixing conduit so that each air jet entrains a portion of the mixture and diverts the mixture radially outward from the premixing conduit. Further, the gas can be guided to form a more uniform air-fuel mixture at the combustion outlet surface of the nozzle, and can be guided into the combustor of the gas turbine. In addition, one or more of the air jets are desirably directed radially outward from the premixing conduit to entrain a portion of the mixture and further guide the mixture radially outward from the premixing conduit. As a result, a more uniform air-fuel mixture is formed at the combustion outlet surface of the nozzle and introduced into the combustion chamber of the gas turbine.

  Those skilled in the art will appreciate more fully the features and aspects of such embodiments upon review of the specification.

  The full and privileged disclosure of the present invention, including the best mode for those skilled in the art, is more specifically described in the following portion of the specification, including references to the accompanying drawings.

1 is a block diagram illustrating a turbine system with a fuel nozzle coupled to a combustor, in accordance with an embodiment of the present technology. FIG. 2 is a cross-sectional view illustrating several portions of a combustor in a gas turbine system of the present disclosure. FIG. 2 is a partial perspective view and a cross-sectional view of an exemplary embodiment of a component of the present invention. FIG. 6 is a cross-sectional view illustrating another exemplary embodiment of a component of the present invention. FIG. 5 is a cross-sectional view along the line of sight designated by 5-5 in FIG. 4. FIG. 6 is a cross-sectional view illustrating a further exemplary embodiment of a component of the present invention. FIG. 6 is a cross-sectional view illustrating yet another exemplary embodiment of a component of the present invention. FIG. 9 is a cross-sectional view illustrating an exemplary alternative embodiment of a section surrounded by a broken line designated by reference numeral 8 in FIG. 6. FIG. 5 is a cross-sectional view illustrating another exemplary embodiment of components of the present invention, similar to the view shown in FIG. 1 is a schematic diagram illustrating an embodiment of the method of the present invention for operating a fuel / air nozzle of a gas turbine engine. FIG. FIG. 6 is a schematic diagram illustrating an alternative embodiment of the method of the present invention for operating a fuel / air nozzle of a gas turbine engine.

  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 of the drawings. Like or similar symbols in the drawings and description are used to refer to like or similar parts in the embodiments of the present invention.

  Each example is provided by way of illustration of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that the present invention can be modified and modified without departing from the scope or spirit of the invention. For example, features illustrated or described as part of one embodiment may be used in another embodiment to yield a still further embodiment. Accordingly, the present invention is intended to embrace all such modifications and variations as fall within the scope of the appended claims and their equivalents.

  It should be understood that the ranges and limits referred to herein include all subranges that are within the specified limits, including the limits themselves, unless otherwise specified. For example, the range of 100-200 includes all possible subranges, for example 100-150, 170-190, 153-162, 145.3-149.6, and 187-200. Further, the limit of 7 or less includes the limits of 5 or less, 3 or less, and 4.5 or less, and includes all subranges within the limits such as about 0 to 5, including 0 and 5; And 5.2-7, including 5.2 and 7.

  Referring to FIG. 1, a simplified diagram of several portions of a gas turbine system 10 is shown. The turbine system 10 may use liquid or gaseous fuel, such as natural gas and / or hydrogen enriched synthesis gas, to operate the turbine system 10. As shown, a plurality of fuel nozzles 12 of the type described in more detail below takes a fuel supply 14, mixes the fuel with air, and distributes the mixture into the combustor 16. The air-fuel mixture burns in a chamber within the combustor 16 thereby creating hot pressurized exhaust gas. The combustor 16 guides the exhaust gas through the turbine 18 toward the exhaust outlet 20. As the exhaust gas passes through the turbine 18, the gas rotates the shaft 22 along the axis of the system 10 by one or more turbine blades. As shown, the shaft 22 may be connected to various components of the turbine system 10 including the compressor 24. The compressor 24 also includes a blade that may be coupled to the shaft 22. As the shaft 22 rotates, the blades in the compressor 24 also rotate so that air from the air intake 26 is compressed through the compressor 24 and enters the fuel nozzle 12 and / or the combustor 16. The shaft 22 may also be connected to a load 28, which may be a permanent load such as a car or a power plant generator or aircraft propeller. As will be appreciated, the load 28 may include any suitable device that can be powered by the rotational output of the turbine system 10.

  FIG. 2 is a simplified cross-sectional view of several portions of the gas turbine system 10 shown schematically in FIG. As shown schematically in FIG. 2, the turbine system 10 includes one or more fuel / air nozzles 12 located at the head end 27 of one or more combustors 16 of a gas turbine engine. Each of the illustrated fuel nozzles 12 may include a plurality of integrated fuel nozzle groups and / or stand-alone fuel nozzles, each of the illustrated fuel nozzles 12 being at least largely or completely internal structural support. (E.g., load bearing fluid passages). With reference to FIG. 2, the system 10 includes a compressor section 24 that pressurizes a gas, such as air, that enters the system 10 via an air intake 26. In operation, air may enter the turbine system 10 via the air intake 26 and be pressurized in the compressor 24. Although the gas may be referred to herein as air, it should be understood that the gas may be any gas suitable for use in the gas turbine system 10. Pressurized air discharged from the compressor compartment 24 is typically delivered by a plurality of combustors 16 (only one of which is shown in FIGS. 1 and 2) arranged in an annular array centered on the axis of the system 10. It flows into the combustor section 16, which is characterized. Air entering the combustor section 16 is mixed with fuel and burned in the combustion chamber 32 of the combustor 16. For example, the fuel nozzle 12 may inject the air-fuel mixture into the combustor 16 at an air / fuel ratio suitable for optimal combustion, exhaust, fuel consumption, and power. Combustion produces hot pressurized exhaust gas that then flows from each combustor 16 to the turbine section 18 (FIG. 1) to drive the system 10 and produce an output. The hot gas drives one or more blades (not shown) in the turbine 18 to rotate the shaft 22 and consequently rotate the compressor 24 and the load 28. As the shaft 22 rotates, the blade 30 in the compressor 24 rotates, and the air received by the intake 26 is drawn in and pressurized. However, the combustor 16 does not necessarily have to be configured as described above and illustrated herein, and generally mixes and burns compressed air and fuel and transfers them to the turbine section 18 of the system 10. It should be readily appreciated that any configuration that allows for

  3-9 schematically illustrate various embodiments of a fuel / air nozzle 12 according to an exemplary embodiment of the present invention. For example, in each of FIGS. 4, 8, and 9, at least each upstream end of each premixing conduit 41 has a fluid flow entering the inlet opening 66 a of each premixing conduit 41 parallel to the central axis 36 of the central body 52. A central axis 41d is defined and arranged to be guided by For example, in each of FIGS. 6 and 7, at least each upstream end of each premixing conduit 41 has a fluid flow entering the inlet opening 66a of each premixing conduit 41 from the central axis 36 of the central body 52 to 0.1. A central axis 41d is defined and arranged to be guided at an acute angle in the range of 20 ° to 20 °. For example, as schematically shown in FIG. 3, one embodiment of the fuel / air nozzle 12 is configured with a concentric axis parallel to the burner tube axis 36 to guide the mixture from the premix pilot nozzle 40 in the axial direction. A premixing conduit 41. In the embodiment schematically shown in FIGS. 4, 5, and 9, there is at least one air jet 42 next to each premix conduit 41, each air jet 42 entraining a portion of the mixture, Leading the air-fuel mixture radially outward from the premixing conduit 41 to form a more uniform air-fuel mixture at the combustion outlet face 44 of the nozzle 12 and leading it into the combustion chamber 32 (FIGS. 1 and 2) of the combustor 16 Can do. In the embodiment shown in FIGS. 4 and 5, each air jet 42 is preferably directed radially outward from the premixing conduit 41, so that each air jet 42 more easily entrains a larger amount of air-fuel mixture. The air-fuel mixture is directed radially outward from the premixing conduit 41 to form a more uniform air-fuel mixture at the combustion outlet face 44 of the nozzle 12 and into the combustion chamber 32 (FIGS. 1 and 2) of the combustor 16. be able to.

  For example, as schematically illustrated in FIG. 3, the fuel / air nozzle 12 of a gas turbine engine desirably includes an axially elongated peripheral wall 50 that defines an outer envelope of the nozzle 12. The peripheral wall 50 of the fuel / air nozzle 12 has an outer surface 50a and an inner surface 50b facing the outer surface 50a and defining an inner cavity 50c that is elongated in the axial direction.

  For example, as schematically shown in FIG. 3, the fuel / air nozzle 12 of the gas turbine engine is desirably disposed within the internal cavity 50c of the fuel / air nozzle 12 and has a central axis 36 that is the same as the central axis of the burner tube. A hollow, axially elongated central body 52 that defines The central body 52 is defined by a central body wall 52a that defines an upstream end 52b and a downstream end 52c disposed on the opposite side of the upstream end 52b in the axial direction. The central body wall 52a is defined by an outer surface 52d and an inner surface 52e facing the outer surface 52d. The inner surface 52 d of the central body wall 52 a defines an axially elongated internal flow path 53 that is disposed concentrically with the central axis 36 of the central body 52. The primary air flow channel 51 is defined in an annular space between the inner surface 50b of the peripheral wall 50 and the outer surface 52d of the central body wall 52a.

  For example, as schematically shown in FIG. 3, the fuel / air nozzle 12 of a gas turbine engine desirably has an axially elongated hollow that extends axially through an internal flow path 53 of a central body 52. A fuel supply path 54 is included. The fuel supply path 54 has an upstream end 54a that is disposed at the upstream end 52b of the center body 52 and is configured to connect to a fuel source (not shown). The fuel supply path 54 has a downstream end portion 54 b disposed at the downstream end portion 52 c of the center body 52. The secondary air flow channel is defined by an annular space between the inner surface 52e of the central body 52 and the outer surface of the fuel supply passage 54, which annular space is an elongated internal flow in the axial direction schematically shown in FIG. A path 53 is defined.

  As schematically shown in FIG. 3, the primary fuel passes through a plurality of air swirler vanes 56 secured to and extending across the flow path of the primary air flow channel 51. Sixteen combustion chambers 32 (FIG. 2) may be supplied. These air swirler vanes 56 define a so-called swozzle that extends radially from the outer surface of the central body wall 52a. As shown schematically in FIG. 3, each swozzle air swirler vane 56 preferably includes an internal fuel conduit 57 that terminates in a fuel injection port or hole 58 from which the conduit 57 Is injected into the primary air (indicated by the arrow designated by 51a) flowing through the fuel injection port 58 of the air swirler vane 56. it can. The primary air flow 51a is directed to the air swirler vane 56 and a swirl pattern is imparted to the primary air flow 51a, thereby causing the air swirler vane into the primary air flow 51a and the passing primary air flow 51a. Mixing with the primary fuel ejected from the 56 holes 58 is facilitated. The primary air flow 51a mixed with the primary fuel may then flow into a pre-mixing annulus defined between the peripheral wall 50 and the inner central body 52, where the primary air flow 51a The air flow 51 a and the primary fuel continue to be mixed with each other before entering the combustion chamber 32.

  For example, as schematically shown in FIG. 3, the fuel / air nozzle 12 of a gas turbine engine is preferably a premixed pilot nozzle with an upstream end 40a connected to a downstream end 52c of the central body 52. 40 is included. In the embodiment shown in FIG. 3, the downstream end 52 c of the central body 52 and the upstream end 40 a of the premix pilot nozzle 40 are partially divided by different sections of the metal tube forming the central body 52, Defined by the outermost wall defining the premix pilot nozzle 40. The premix pilot nozzle 40 has a downstream end 40b disposed on the opposite side in the axial direction from the upstream end 40a of the premix pilot nozzle 40.

  For example, as schematically shown in FIGS. 3, 4, and 9, the premix pilot nozzle 40 defines a pilot fuel nozzle 60 that defines an upstream end 60a and a downstream end 60b. For example, as shown schematically in FIGS. 4 and 9, the upstream end 60 a of the pilot fuel nozzle 60 is connected in fluid communication with the downstream end 54 b of the fuel supply path 54. The downstream end 60 b of the pilot fuel nozzle 60 defines at least one fuel jet 61 configured in fluid communication with the upstream end 60 a of the pilot fuel nozzle 60. For example, as schematically shown by the arrow designated 62 in FIGS. 4 and 9, the fuel 62 entering the pilot fuel nozzle 60 via the downstream end 54b of the fuel supply passage 54 is a plurality of fuel jets 61 ( The pilot fuel nozzle 60 is exited via (shown in phantom in FIG. 5).

  For example, as schematically shown in FIGS. 3, 4, and 9, the premix pilot nozzle 40 is further radially outward from the pilot fuel nozzle 60 and preferably relative to the burner tube axis 36 shown in FIG. And defining an annular fuel plenum wall 63 arranged concentrically. For example, as schematically illustrated in FIGS. 3, 4, and 9, the fuel plenum wall 63 defines a fuel plenum 64 between the pilot fuel nozzle 60 and the fuel plenum wall 63. For example, as schematically shown in FIGS. 4 and 9, the fuel plenum wall 63 further defines a plurality of fuel holes 63a through which fuel is discharged from the fuel plenum 64. For example, as schematically shown in FIGS. 4 and 9, at least one of the fuel holes 63 a is connected in fluid communication with at least one of the fuel jets 61 via a fuel plenum 64. Desirably, each of the fuel holes 63a is connected in fluid communication with each of the fuel jets 61 via a fuel plenum 64.

  For example, as schematically shown in FIGS. 3, 4, and 9, the premix pilot nozzle 40 further includes a plurality of axially elongated hollow premix conduits disposed radially outward from the fuel plenum wall 63. 41 is specified. For example, as schematically shown in the embodiment shown in FIGS. 4 and 9, each premix conduit 41 is desirably defined in part by a plenum wall 63. For example, as schematically shown in FIG. 3, each premixing conduit 41 has an upstream end 41 a that is disposed near the downstream end 52 c of the central body 52. For example, as schematically shown in FIGS. 4 and 9, each premix conduit 41 defines an inlet opening 66a in fluid communication with the internal flow path 53 of the central body 52 at its upstream end 41a. The arrows designated 53a in FIGS. 4 and 9 schematically show the air flow 53a entering the inlet opening 66a of each premixing conduit 41 from the internal flow path 53 of the central body 52.

  For example, as schematically shown in FIGS. 4 and 9, each premix conduit 41 is connected in fluid communication with at least one of the fuel holes 63 a defined in the fuel plenum wall 63 of the fuel plenum 64. The arrows designated 62 a in FIGS. 4 and 9 schematically show the fuel flow 62 a that exits the fuel plenum 64 through the fuel holes 63 a defined in the fuel plenum wall 63 and enters each premixing conduit 41. The arrows designated 62b in FIGS. 4 and 9 schematically show the mixture flow 62b moving downstream in the premix conduit 41 of the premix pilot nozzle 40.

  For example, as schematically shown in FIGS. 4 and 9, each premixing conduit 41 is disposed axially opposite the upstream end 41 a of the premixing conduit 41, and the downstream end of the premixing pilot nozzle 40. It has a downstream end 41b disposed in the vicinity of 40b. For example, as schematically shown in FIGS. 4 and 9, the downstream end 41b of each premix conduit 41 each has an outlet that allows fluid, ie, the mixture 62b, to be discharged from the hollow premix conduit 41. An opening 66b is defined. For example, as schematically shown in FIGS. 4 and 9, the downstream end 41b of each premixing conduit 41 defines a central axis 41c, and the wall defining each premixing conduit 41 defines this central axis 41c. Centered and concentric. Further, for example, as schematically shown in the embodiment of the premix pilot nozzle 40 shown in FIGS. 4 and 9, each central axis 41c is a mixture that discharges from the outlet opening 66b of each premix conduit 41. The fluid flow is a straight line arranged so as to be guided parallel to the central axis 36 of the central body 52.

  The air-fuel mixture 62b tends to diffuse radially from each central axis 41c as the air-fuel mixture 62b leaves the outlet opening 66b of each premixing conduit 41. It is not noticeable. In fact, Applicants' study shows that the equivalence ratio in the section of the combustion outlet face 44 (FIGS. 4 and 9) located immediately downstream of the outlet opening 66b of each premixing conduit 41 is that of the central body 52. It has been shown that it can be approximately twice the equivalence ratio present in the section of the combustion exit face 44 (FIGS. 4 and 9) located immediately downstream of the central axis 36. A high equivalence ratio at a position immediately downstream of the outlet opening 66b of each premix conduit 41 can ignite the mixture through the axially elongated internal cavity 50c (FIG. 3) continuously and effectively, Even if the flame is in a lean-blow-out (LBO) condition, the flame can be stabilized. This is one of the important roles of the premix pilot, and the premix pilot 60 plays this role without increasing NOx.

  Various embodiments of the present invention offset this much higher equivalence ratio present in the section of the combustion outlet face 44 (FIGS. 4 and 9) located immediately downstream of the outlet opening 66b of each premix conduit 41. Including features. For example, as shown schematically in the embodiment of the premix pilot nozzle 40 shown in FIGS. 3, 4, 5, and 9, the premix pilot nozzle 40 is further disposed radially outward from the premix conduit 41. An annular channel 70 is defined. For example, in the embodiment shown in FIGS. 3, 4, 5, and 9, the inner wall 43 of the annular channel 70 also serves to define the outer wall 43 of the premixing conduit 41. For example, in the embodiments shown in FIGS. 3, 4, 5, and 9, the central body wall 52a also serves to define the outer wall 52a of the annular channel 70.

  For example, as shown schematically in the embodiment of the premix pilot nozzle 40 shown in FIGS. 3, 4, and 9, the upstream end of the annular channel 70 is in fluid communication with the internal flow path 53 of the central body 52. Therefore, the air flow is received from the internal flow path 53 of the central body 52. A plurality of air jets 42 are defined at the downstream end of the annular channel 70. At least one of the air jets 42 is disposed near at least one of the at least one outlet opening 66b of the premix conduit 41. Desirably, for example, as shown in FIGS. 4, 5, and 9, at least one of the air jets 42 is disposed near each outlet opening 66 b of each premix conduit 41.

  For example, as schematically shown in FIG. 9, each flow path defining one of the air jets 42 has a central axis disposed parallel to the central axis 41 c of the downstream end 41 b of the nearby premixing conduit 41. It is defined concentrically around 42a. At that time, the higher-speed air leaving each air jet 42 mixes a part of the air-fuel mixture leaving the premixing conduit 41, and the combustion outlet surface located immediately downstream of the outlet opening 66 b of each premixing conduit 41. It serves to guide the air-fuel mixture present in the compartment 44 (FIG. 9). The overall result is that the equivalence ratio at the combustion exit face 44 (FIG. 9) of the fuel / air nozzle 12 is more uniform and can also be used as a pilot by the ignition source.

  For example, as schematically shown in FIG. 4, each flow path defining one of the air jets 42 is disposed at an acute angle with respect to the central axis 41c of the downstream end 41b of the nearby premix conduit 41. It is defined concentrically about the central axis 42a. The magnitude of this acute angle is desirably in the range of 0.1 ° to 20 °. Furthermore, the air jets 42 in the embodiment of FIG. 4 desirably cause individual air jets 42 to direct the air flow exiting the air jets 42 away from the vicinity of one of the outlet openings 66b of the premix conduit 41. Thus, it is configured and arranged. Thus, for example, in the embodiment schematically illustrated in FIG. 4, each air jet 42 is configured such that the air leaving the air jet 42 is in a downstream direction and radially away from the central axis 36 of the central body 52. , As well as in a direction radially away from the central axis 41c of the downstream end 41b of the adjacent individual premixing conduit 41. At that time, the air leaving each air jet 42 mixes a part of the air-fuel mixture leaving the premixing conduit 41, and the combustion outlet face 44 (see FIG. 5) located immediately downstream of the outlet opening 66 b of each premixing conduit 41. 9) plays a role of guiding the air-fuel mixture existing in the section radially outward toward the peripheral wall 50 (FIG. 3). The overall result is that the equivalence ratio at the combustion outlet face 44 (FIG. 4) of the fuel / air nozzle 12 is more uniform and can also be used as a pilot by the ignition source.

  For example, in another embodiment of the invention schematically illustrated in FIG. 6, except for the premixed pilot nozzle 40 embodiment schematically illustrated in FIG. 6, the embodiment of FIG. , And the same as the ninth embodiment. As shown schematically in FIG. 6, each premixing conduit 41 itself is concentric about a central longitudinal axis 41c disposed at an acute angle with respect to the central axis 36 of the central body 52. The magnitude of this acute angle is desirably in the range of 0.1 ° to 20 °. Thus, in the premix pilot nozzle 40 shown schematically in FIG. 6, each premix conduit 41 causes the air mixture exiting the exit opening 66 b of each premix conduit 41 to move radially outward from the central axis 36 of the central body 52. Directed away to form a more uniform mixture at the combustion exit face 44 of the fuel / air nozzle 12 and lead it into the combustion chamber of the gas turbine 10 and an internal cavity elongated in the axial direction of the fuel / air nozzle 12 It is constructed and arranged to ignite the mixture supplied through 50c (FIG. 3) continuously and effectively. For example, although not specifically illustrated in FIG. 6, the one or more axial lengths of the premix conduit 41 appear to be concentric about the central axis 41 c of the downstream end 41 b of the premix conduit 41. Thus, it can extend beyond the downstream end 40 b of the premix pilot nozzle 40.

  For example, in another embodiment of the present invention schematically illustrated in FIG. 8, the embodiment of FIG. 8 is a diagram, except for the embodiment of the premixing conduit 41 of the premixing pilot nozzle 40 schematically illustrated in FIG. Similar to the 3, 4, 5, 6, and 9 embodiments. In the embodiment schematically shown in FIG. 8, the premixing conduits 41 themselves are each concentric about a two-way central longitudinal axis having a first leg 41d and a second leg 41c. . As schematically shown in FIG. 8, the first leg 41 d of the two central longitudinal axes is arranged parallel to the central axis 36 of the central body 52, and the upstream end 41 a of each premixing conduit 41. And the downstream end 41b. The second leg 41 c of the two central longitudinal axes is arranged at an acute angle with respect to the central axis 36 of the central body 52 and extends through the downstream end 41 b of each premixing conduit 41. The magnitude of this acute angle is desirably in the range of 0.1 ° to 20 °. Accordingly, the premixing conduit 41 shown schematically in FIG. 8 guides the air-fuel mixture exiting from the outlet opening 66b away radially outward from the central axis 36 of the central body 52 so that the fuel / air nozzle 12 A more uniform air-fuel mixture is formed at the combustion outlet surface 44 and is introduced into the combustion chamber of the gas turbine 10 and is continuous with the air-fuel mixture supplied through the internal cavity 50c (FIG. 3) elongated in the axial direction of the fuel / air nozzle 12. And is arranged and arranged to ignite effectively.

  For example, in another embodiment of the invention schematically illustrated in FIG. 7, an embodiment of the premixing conduit 41 and annular channel 70 of the premixing pilot nozzle 40 schematically illustrated in FIGS. Except for this, the embodiment of FIG. 7 is similar to the embodiments of FIGS. As shown schematically in FIG. 7, each premixing conduit 41 itself is concentric about a central longitudinal axis 41 c that is disposed at an acute angle with respect to the central axis 36 of the central body 52. The magnitude of this acute angle is desirably in the range of 0.1 ° to 20 °. Thus, in the premix pilot nozzle 40 schematically shown in FIG. 7, each premix conduit 41 causes the air-fuel mixture exiting from the outlet opening 66b of each premix conduit 41 to move radially outward from the central axis 36 of the central body 52. Directed away to form a more uniform mixture at the combustion exit face 44 of the fuel / air nozzle 12 and lead it into the combustion chamber of the gas turbine 10 and an internal cavity elongated in the axial direction of the fuel / air nozzle 12 It is constructed and arranged to ignite the mixture supplied through 50c (FIG. 3) continuously and effectively.

  For example, as schematically shown in the embodiment of the premix pilot nozzle 40 shown in FIG. 7, the upstream end of the annular channel 70 is an air jet disposed next to each outlet opening of the premix conduit 41. It is comprised so that it may taper as it goes downstream toward 42. As described above with respect to the embodiment of FIGS. 3, 4, and 5, each air jet 42 is directed radially outwardly from the premixing conduit 41 so that each air jet 42 entrains a portion of the mixture. Thus, the air-fuel mixture is further guided radially outward from the premixing conduit 41 to form a more uniform air-fuel mixture at the combustion outlet face 44 of the fuel / air nozzle 12 and the combustion chamber 32 (FIG. 1 and FIG. 1). 2) The air / fuel mixture supplied through the internal cavity 50c (FIG. 3) elongated in the axial direction of the fuel / air nozzle 12 can be ignited continuously and effectively.

  Each embodiment of the premix pilot nozzle 40 provides a small well anchored premixed flame near the base of the fuel / air nozzle 12 so that it exits the fuel / air nozzle 12. The swirling mixture is fixed. Improved flame stability enables reduced air-mix operation, resulting in an extended LBO and exhaust operability window.

  The fuel / air nozzle 12 as in the embodiment described above makes it possible to implement an advantageous method of operating the fuel / air nozzle 12 of the gas turbine engine 10. One embodiment of such a method of operating the fuel / air nozzle 12 of the gas turbine engine 10 desirably downstream of the next primary air flow 51a (eg, FIG. 3), shown schematically in FIG. 10, from the swozzle. The primary air flow vortex, and the primary fuel flow 57a (eg, FIG. 3) is delivered through the swozzle to form a vortex downstream of the swozzle. Step 82 for mixing with 51a; Step 83 for delivering pilot fuel flow 62 (eg, FIG. 4) through the hollow fuel supply path 54 to the premix pilot nozzle 40; and Secondary air flow 53a (eg, FIG. 4). ) Through the central body 52 (eg, FIG. 3) downstream to the premix pilot nozzle 40, and the mixture 62b (eg, FIG. 3). And 9) mix pilot fuel 62 with secondary air flow 53a in a plurality of axially elongated hollow premix conduits 41 (eg, FIG. 4) that discharge from downstream end 41b of premix pilot nozzle 40. Step 85, and step 86 of ejecting the air-fuel mixture 62b from the premixing conduit 41 of the premixing pilot nozzle 40 in a direction away from the central axis 36 (eg, FIGS. 3, 4, and 6-9) of the central body 52; including.

  Another embodiment of such a method of operating the fuel / air nozzle 12 of the gas turbine engine 10 desirably provides a subsequent primary air flow 51a (eg, FIG. 3), as schematically illustrated in FIG. Deliver downstream to create a vortex of primary air flow 81 and deliver primary fuel flow 57a (eg, FIG. 3) through the swozzle to form a vortex downstream of the swozzle. Step 82 for mixing with the flow 51a, Step 83 for delivering the pilot fuel flow 62 (eg, FIG. 4) through the hollow fuel supply path 54 to the premix pilot nozzle 40, and a secondary air flow 53a (eg, FIG. 4) delivering 84 downstream through the central body 52 (eg, FIG. 3) to the premix pilot nozzle 40, and the mixture 62b (eg, 4 and 9) in a plurality of axially elongated hollow premix conduits 41 (eg, FIG. 4) that discharge from the downstream end 41b of the premix pilot nozzle 40, pilot fuel 62 and secondary air flow 53a. Mixing step 85 and a portion of the secondary air flow 53a (eg, FIGS. 4, 7, and 9) to an annular channel 70 disposed radially outward from the premixing conduit 41 of the premixing pilot nozzle 40. Delivering 87 and ejecting air 88 from the annular channel 70 in a direction away from the premix pilot nozzle 40 (eg, FIGS. 4, 7 and 9). Desirably, the pressure of the air ejected from the annular channel 70 exceeds the pressure of the air entering the annular channel 70. Desirably, for example, as shown schematically in FIG. 7, the annular channel 70 includes an upstream end configured to taper as it proceeds in the downstream direction. Desirably, for example, as schematically illustrated in FIG. 7, a further embodiment of the method ejects the mixture from the premix conduit 41 of the premix pilot nozzle 40 in a direction away from the central axis 36 of the central body 52. Includes steps. Desirably, for example, as schematically illustrated in FIG. 4, a further embodiment of the method removes the mixture 62b from the premix conduit 41 of the premix pilot nozzle 40 in a direction parallel to the central axis 36 of the central body 52. Including a step of ejecting. Desirably, a further embodiment of the method, for example, schematically shown in FIGS. 4 and 7, squirts the air-fuel mixture 62b from the annular channel 70 in a direction radially away from the central axis 36 of the central body 52. including.

  This written description uses examples to disclose the invention, including the best mode, and to enable any person skilled in the art to make and use the invention, including the creation and use of any device or system and the practice of any integrated method. Make it possible to implement. 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 embodiments are intended to be within the scope of the claims if they contain structural elements that do not differ from the claim language, or equivalent structural elements that do not substantially differ from the claim language. To do.

DESCRIPTION OF SYMBOLS 10 Turbine system 12 Fuel / air nozzle 14 Fuel supply 16 Combustor 18 Turbine 20 Exhaust outlet 22 Shaft 24 Compressor 26 Air intake 27 Head side edge 28 Load 30 Blade 32 Combustion chamber 36 Center axis 40 Premix pilot nozzle 41 Premix conduit 41a Upstream end 41b Downstream end 41c Central axis 41c Second leg 41d Central axis 41d First leg 42 Air jet 43 Inner wall outer wall 44 Combustion exit surface 50 Peripheral wall 50a Outer surface 50b Inner surface 50c Internal cavity 51 Primary air flow channel 51a Primary air flow 52 Central body 52a Central body wall 52b Upstream end 52c Downstream end 52d Outer surface 53 Internal flow path 53a Air flow 54a Upstream end 54b Downstream end 56 Air Swivel vane 57 conduit 57a primary Fuel flow 58 Fuel injection port 60 Fuel nozzle 60a Upstream end 60b Downstream end 61 Fuel jet 62 Fuel 62a Fuel flow 62b Mixture flow 63 Fuel plenum wall 64 Fuel plenum 66a Inlet opening 66b Outlet opening 70 Annular channel 81 Step 82 Step 83 Step 84 Step 85 Step 86 Step 87 Step 88 Step

Claims (29)

An axially elongated peripheral wall defining an outer envelope of the fuel / air nozzle, having an outer surface and an inner surface facing the outer surface, and defining an axially elongated inner cavity;
A hollow axially elongated central body disposed within the internal cavity of the fuel / air nozzle and defining a central axis, the axial end opposite the upstream end and the upstream end A central body wall defining a downstream end, wherein the central body wall is defined by an outer surface and an inner surface facing the outer surface, the inner surface of the central body wall being the center A central body defining an internal flow path elongated in an axial direction concentrically disposed about the central axis of the body; and
An elongate hollow fuel supply passage that extends in the axial direction through the internal flow path of the central body, and is disposed at the upstream end of the central body and configured to connect to a fuel source A fuel supply path having an upstream end and a downstream end disposed at the downstream end of the central body;
A primary air flow channel defined by an annular space between the outer surface of the central body and the inner surface of the peripheral wall;
A premix pilot nozzle having an upstream end connected to the downstream end of the central body, the downstream end disposed on the opposite side in the axial direction of the upstream end of the premix pilot nozzle A premixed pilot nozzle having
The premix pilot nozzle further defines a plurality of axially elongated hollow premix conduits, each of the premix conduits being disposed near the downstream end of the central body, At least an upstream end defining an inlet opening in fluid communication with the internal flow path, and each of the premix conduits is connected in fluid communication with the downstream end of the fuel supply path Each of the premix conduits has a downstream end defining an outlet opening that allows fluid to be discharged from the hollow premix conduit. downstream end, respectively, defining a central axis which is inclined radially outwardly against the central axis of the central body, the fuel / air nozzle of a gas turbine engine.   The fuel / air nozzle of claim 1, wherein each of the central axes of at least one premixing conduit is disposed at an acute angle with respect to the central axis of the central body. The premix pilot nozzle further defines an annular channel disposed radially outward from the premix conduit, wherein the annular channel is configured in fluid communication with the internal flow path of the central body; There defining a plurality of air jets, wherein at least one of the air jets, while being disposed one near at least one of the outlet opening of the premixing duct, having a central axis, claim 1 or claim 2. The fuel / air nozzle according to 2.   The fuel / air of claim 3, wherein the central axis of the upstream end of the at least one premixing conduit is constructed and arranged to extend in a direction parallel to the central axis of the central body. nozzle. The fuel / air nozzle according to claim 3 or 4 , wherein at least one central axis of the air jet forms an acute angle with the central axis of the central body. The fuel / air nozzle according to any one of claims 3 to 5, wherein the annular channel is configured to taper as it travels downstream toward the air jet. A swozzle including a plurality of swirling blades extending radially across the primary air flow channel, wherein at least one of the swirling blades has an inlet at one end and the primary air flow channel and fluid at the opposite end; 7. A fuel / air nozzle as claimed in any one of the preceding claims , defining a fuel conduit having an outlet in communication therewith. The premix pilot nozzle defines a pilot fuel nozzle, the pilot fuel nozzle defines an upstream end and a downstream end, and the upstream end of the pilot fuel nozzle is the downstream side of the fuel supply path Defining at least one fuel jet connected in fluid communication with an end, wherein the downstream end of the pilot fuel nozzle is configured in fluid communication with the upstream end of the pilot fuel nozzle;
The premix pilot nozzle is disposed radially outward from the pilot fuel nozzle and further defines a fuel plenum wall defining a fuel plenum between the pilot fuel nozzle and a fuel plenum wall; A wall further defines a plurality of fuel holes, wherein at least one of the fuel holes is connected in fluid communication with at least one of the fuel jets through the fuel plenum, and the premixing conduits are each connected to the fuel plenum wall. 8. A fuel / air nozzle according to any one of the preceding claims , disposed radially outward from and in fluid communication with at least one of the fuel holes. The head side end,
A combustor for a gas turbine engine, comprising: at least one fuel / air nozzle according to any one of claims 1 to 8 supported by the head side end . A method of operating a fuel / air nozzle for improving flame stability and NOx of a gas turbine engine, wherein the fuel / air nozzle is disposed within the peripheral wall, the hollow wall defining the central axis and within the peripheral wall A central body, a swozzle extending radially from the outside of the upstream end of the central body and radially toward the peripheral wall, and a plurality of preliminary openings having an outlet opening at the downstream end of the central body. In a method of operation defined by a premix pilot nozzle including a mixing conduit,
Delivering a primary air flow downstream of the swozzle to create a swirl of the primary air flow;
Delivering a primary fuel flow through the swozzle to mix with the primary air flow forming a swirl downstream of the swozzle;
Delivering a pilot fuel flow to the premix pilot nozzle through a hollow fuel supply path;
Delivering secondary air flow downstream through the central body to the premix pilot nozzle;
With respectively define a central axis that is inclined radially outwardly against the central axis of the central body at the downstream end, to release the mixing Aiki from the downstream end of the premix pilot nozzle, Mixing the pilot fuel with the secondary air flow in a plurality of axially elongated hollow premix conduits;
Ejecting the air-fuel mixture from the outlet opening of the premixing conduit of the premixing pilot nozzle. The method of claim 10 , further comprising ejecting the air-fuel mixture from the premixing conduit of the premixing pilot nozzle in a direction radially away from the central axis of the central body. 12. The method of claim 10 or claim 11 , further comprising diverting a portion of the secondary air flow into an annular channel disposed radially outward from the premixing conduit of the premixing pilot nozzle. The pressure of air ejected from the annular channel, exceeds the pressure of the air entering the said annular channel, The method of claim 12, wherein. 14. A method according to claim 12 or claim 13 , wherein the annular channel tapers as it travels in the downstream direction. 15. A method according to any one of claims 12 to 14 , further comprising injecting air from the annular channel of the premix pilot nozzle in a direction away from the outlet opening of the premix conduit. The method of claim 15 , wherein the air ejected from the annular channel is directed in a direction away from the central axis of the central body. An axially elongated peripheral wall defining an outer envelope of the fuel / air nozzle, having an outer surface and an inner surface facing the outer surface, and defining an axially elongated inner cavity;
A hollow axially elongated central body that is disposed within the internal cavity of the fuel / air nozzle and defines a central axis, the upstream end and the axially opposite side of the upstream end. A central body wall defining a downstream end, wherein the central body wall is defined by an outer surface and an inner surface facing the outer surface, and the inner surface of the central body wall is A central body defining an elongated internal flow path in an axial direction arranged concentrically about the central axis of the central body;
An elongate hollow fuel supply passage that extends in the axial direction through the internal flow path of the central body, and is disposed at the upstream end of the central body and configured to connect to a fuel source A fuel supply path having an upstream end and a downstream end disposed at the downstream end of the central body;
A primary air flow channel defined by an annular space between the outer surface of the central body and the inner surface of the peripheral wall;
A premix pilot nozzle having an upstream end connected to the downstream end of the central body, the downstream end being disposed on an axially opposite side of the upstream end of the premix pilot nozzle A premix pilot nozzle having a portion,
The premix pilot nozzle further defines a plurality of axially elongated hollow premix conduits, each of the premix conduits being disposed near the downstream end of the central body, At least an upstream end defining an inlet opening in fluid communication with the internal flow path, and each of the premix conduits is connected in fluid communication with the downstream end of the fuel supply path Defining a fuel hole, each of the premix conduits having a downstream end defining an outlet opening that allows fluid to be discharged from the hollow premix conduit, the upstream of the premix conduit each side edge is at least defining a central axis, wherein the premix conduit entrance Ru Fluid flow to the inlet opening of each of which is constructed and arranged to be directed parallel to the central axis of the central body,
The fuel / air nozzle of a gas turbine engine further comprising an annular channel disposed radially outward from the premixing conduit, the annular channel configured in fluid communication with the internal flow path of the central body. . The fuel / air nozzle of claim 17 , wherein the upstream end of at least one premixing conduit defines a central axis that is not parallel to the central axis of the downstream end of at least one premixing conduit. 19. A fuel / air nozzle as claimed in claim 17 or claim 18, wherein the annular channel defines a plurality of air jets at its downstream end. At least one of the air jets, while being disposed one near at least one of the outlet opening of the premixing duct, having a central axis that forms the central axis an acute angle of the central body, according to claim 19 The fuel / air nozzle as described. 21. The fuel / air nozzle of claim 20 , wherein at least one central axis of the air jet directs air flow exiting the air jet away from the central axis of the central body. The fuel / air nozzle according to any one of claims 19 to 21, wherein the annular channel is configured to taper as it proceeds downstream toward the air jet. The head side end,
23. A combustor for a gas turbine engine, comprising: at least one fuel / air nozzle according to any one of claims 17 to 22 supported by the head side end . A method of operating a fuel / air nozzle of a gas turbine engine, the fuel / air nozzle, the peripheral wall and a hollow central body defining a central axis while being disposed in said peripheral wall, the upper flow of the central body from the outside of the side end portion, and a swozzle extending radially toward the peripheral wall, the underlying stream side end portion of the central body, premixed pilot nozzle including a plurality of premix conduit having an outlet opening In the operation method defined by
Delivering a primary air flow downstream of the swozzle to create a swirl of the primary air flow;
Delivering a primary fuel flow through the swozzle to mix with the primary air flow forming a swirl downstream of the swozzle;
Delivering a pilot fuel flow to the premix pilot nozzle through a hollow fuel supply path;
Delivering secondary air flow downstream through the central body to the premix pilot nozzle;
The mixture plurality of axially within elongated hollow premix conduits emanating from the lower stream side end portion of the premixed pilot nozzle, comprising the steps of mixing the pilot fuel and the secondary air flow,
Diverting a portion of the secondary air flow into an annular channel disposed radially outward from the premix conduit of the premix pilot nozzle;
Ejecting the air-fuel mixture from the outlet opening of the premixing conduit of the premixing pilot nozzle. 25. The method of claim 24 , further comprising ejecting the air-fuel mixture from the premixing conduit of the premixing pilot nozzle in a direction parallel to the central axis of the central body. 26. A method according to claim 24 or claim 25 , further comprising the step of ejecting the air-fuel mixture from the premixing conduit of the premixing pilot nozzle in a direction radially away from the central axis of the central body. The pressure of air ejected from the annular channel, exceeds the pressure of the air entering the annular channel, any one method according to claim 24 or claim 26. 28. A method according to any one of claims 24 to 27, wherein the annular channel tapers as it progresses in the downstream direction. 29. A method according to any one of claims 24 to 28 , further comprising injecting air from the annular channel of the premix pilot nozzle in a direction away from the outlet opening of the premix conduit.