Abstract: A method of operating a gas turbine engine combustion system at lower load conditions while maintaining required emissions levels is disclosed. The present invention includes multiple embodiments of axial, radial, and circumferential fuel staging within a can-type combustor having alternate ignition techniques of spark ignition or torch ignition.

Abstract: A combustor dome assembly for a gas turbine engine having a longitudinal centerline axis extending therethrough, including: an annular dome plate having an inner portion, an outer portion, a forward surface, and a plurality of circumferentially spaced openings formed therein, wherein a radial section defined between each of the openings includes a cooling trough formed therein; an outer cowl connected to the dome plate outer portion at a downstream end thereof; an inner cowl connected to the dome plate inner portion at a downstream end thereof; and, a deflector plate connected to and positioned aft of each opening in the dome plate.

Abstract: A gas turbine combustor has a combustion chamber into which fuel and air are supplied, wherein the fuel and the air are supplied into said combustion chamber as a plurality of coaxial jets.

Abstract: The present invention relates to an improved multi-point injector for use in a gas turbine engine or other types of combustors. The multi-point fuel injector has a plurality of nozzles arranged in at least two arrays such as concentric rings. The injector further has different fuel circuits for independently controlling the fuel flow rate for the nozzles in each of the arrays. Each of the nozzles include a fluid channel and one or more swirler vanes in the fluid channel for creating a swirling flow within the fluid channel. A method for injecting a fuel/air mixture into a combustor stage of a gas turbine engine is also described. At least one zone has a flame hot enough to stabilize the entire combustor flame.

Abstract: Aspects of the invention relate to a method for facilitating the reduction of carbon monoxide emissions during part load operation of a turbine engine by holding high combustor temperatures. The combustor section of the turbine engine includes a plurality of combustors, each combustor having a pilot nozzle, a plurality of main nozzles circumferentially surrounding the pilot nozzle, and a premix ring. According to one aspects of the invention, a first pair of combustors are selected. Fuel can be substantially restricted from being supplied to the main nozzles and the premix ring of the selected combustors, while fuel continues to be supplied to the pilot nozzles of the selected combustors. Additional combustors can be selected and the supply of fuel can be selectively restricted as described above. The process can continue until there is substantially zero net power out of the engine.

Abstract: In a burner arrangement for the annular combustion chamber of a gas turbine, a plurality of burners are arranged above one another, in each case in pairs in the radial direction, on concentric rings. In a burner arrangement of this type, the mechanical integrity of the turbine casing is increased and operation of the combustion chamber is optimized by virtue of the two burners in a pair of burners being oriented out of the parallel position, in such a manner that their burner axes converge in the direction of flow.

Abstract: In a fuel injector circuit for a gas turbine engine, a fuel staging valve assembly for distributing fuel into multiple zones in the combustor, the staging valve assembly, including a pilot valve operatively interconnected with at least one main valve, having high pressure and no leak capabilities, which are used to open, close and modulate the mass flow rate volume of fuel within the fuel injection circuit, with the position of the normally-closed valve being controlled by the pressure difference between the nozzle fuel supply circuit and a separately supplied signal circuit. As long as the desired pressure differential is maintained, fuel flow may be modulated without affecting the position of the valve, with the valve seats and valve seals being so configured as to prevent fuel leakage into the downstream nozzle circuit under these conditions.

Abstract: This invention relates to a fuel injection system for a staged combustion chamber (1) of a gas turbine aero-engine, in which a certain quantity of fuel is permanently supplied to the pilot burner(s) (3) and in which fuel is apportioned to the main burner(s) (4) only at higher engine performance, whereby a staging valve unit (7) which variably splits the total fuel mass flow (WF) to the pilot burners (3) and to the main burners (4) is provided downstream of a control valve unit (6) which controls the entire fuel mass flow, with both valve units being actuated by an engine control unit (8) and with the actuation of the staging valve unit (7) being accomplished on the basis of the desired engine performance, characterized in that the engine performance is described by way of a staging parameter (SP) reflecting the load of the gas turbine combustion chamber (1) and actuating the staging control unit (7) according to a switching line, in that the staging parameter (SP) is derived from a functional relationship, in

Abstract: A fuel injector system that reduces and/or eliminates combustion instability. The fuel injector system includes a pilot fuel injector, a pilot swirler that swirls air past the pilot fuel injector, a main airblast fuel injector having an aft end, inner and outer main swirlers that swirl air past the main airblast fuel injector, and an air splitter located between the pilot swirler and the inner main swirler. The air splitter includes at least one aft end cone angled radially outboard and axially positioned downstream of the main airblast fuel injector aft end. The air splitter divides a pilot air stream exiting the pilot swirler from an inner main air stream exiting the inner main swirler to create a bifurcated recirculation zone.

Abstract: A combustor includes outer and inner liners joined together by a dome to define a combustion chamber. A row of air swirlers is mounted in the dome and includes corresponding main fuel injectors for producing corresponding fuel and air mixtures. Pilot fuel injectors fewer in number than the main injectors are mounted in the dome between corresponding ones of the swirlers. Staged fuel injection from the pilot and main injectors is used for starting the combustor during operation.

Abstract: The present invention relates to an improved multi-point injector for use in a gas turbine engine or other types of combustors. The multi-point fuel injector has a plurality of nozzles arranged in at least two arrays such as concentric rings. The injector further has different fuel circuits for independently controlling the fuel flow rate for the nozzles in each of the arrays. Each of the nozzles include a fluid channel and one or more swirler vanes in the fluid channel for creating a swirling flow within the fluid channel. A method for injecting a fuel/air mixture into a combustor stage of a gas turbine engine is also described. At least one zone has a flame hot enough to stabilize the entire combustor flame.

Abstract: A three-stage lean burn combustion chamber (28) comprises a primary combustion zone (36), a secondary combustion zone (40) and a tertiary combustion zone (44). Each of the combustion zones (36, 40, 44) is supplied with premixed fuel and air by respective fuel and air mixing ducts (54, 70, 92). The fuel and air mixing ducts (54, 70, 92) have a plurality of air injection slots (62, 64, 76, 98) spaced apart transversely to the direction of flow through the fuel and air mixing ducts (54, 70, 92). The air injection slots (62, 64, 76, 98) extend in the direction of flow through the fuel and air mixing ducts (54, 70, 92) to the reduce the magnitude of the fluctuations in the fuel to air ratio of the fuel and air mixture supplied into the at least one combustion zone (36, 40, 44). This reduces the generation of harmful vibrations in the combustion chamber (28).

Abstract: Manifolds are shaped cross star having curved surfaces inside thereof, and holes are bored in four corners of the manifolds. In mounting a combustor to a casing, oil in the manifolds is transmitted to the holes by way of the curved surfaces. As a result of this, oil is prevented from staying, and coking is prevented from occurring, inside the manifolds.

Abstract: A gas turbine engine combustor can downstream of a pre-mixer has a pre-mixer flowpath therein and circumferentially spaced apart swirling vanes disposed across the pre-mixer flowpath. A primary fuel injector is positioned for injecting fuel into the pre-mixer flowpath. A combustion chamber surrounded by an annular combustor liner disposed in supply flow communication with the pre-mixer. An annular trapped dual vortex cavity located at an upstream end of the combustor liner is defined between an annular aft wall, an annular forward wall, and a circular radially outer wall formed therebetween. A cavity opening at a radially inner end of the cavity is spaced apart from the radially outer wall. Air injection first holes are disposed through the forward wall and air injection second holes are disposed through the aft wall. Fuel injection holes are disposed through at least one of the forward and aft walls.

Abstract: A gas turbine combustion system having reduced emissions and improved flame stability at multiple load conditions is disclosed. The improved combustion system accomplishes this through complete premixing, a plurality of fuel injector locations, combustor geometry, and precise three dimensional staging between fuel injectors. Axial, radial, and circumferential fuel staging is utilized including fuel injection proximate air swirlers. Furthermore, strong recirculation zones are established proximate the introduction of fuel and air premixture from different stages to the combustion zone. The combination of the strong recirculation zones, efficient premixing, and staged fuel flow thereby provide the opportunity to produce low emissions combustion at various load conditions.

Abstract: A gas turbine combustor has a combustion chamber into which fuel and air are supplied, wherein the fuel and the air are supplied into said combustion chamber as a plurality of coaxial jets.

Abstract: A gas turbine combustor is provided with a nozzle extension tube having an inclination outward in a diameter direction of a combustor inner cylinder and in a peripheral direction of the combustor inner cylinder. As a result, the premixed gas is transformed to a spiral flow passing into a combustion chamber while turning, i.e., an outward turning flow, thereby sufficiently mixing the premixed gas while the premixed gas is flowing in the combustion chamber.

Abstract: A gas turbine combustor has a combustion chamber into which fuel and air are supplied, wherein the fuel and the air are supplied into said combustion chamber as a plurality of coaxial jets.

Abstract: A method for providing a gas turbine engine and a combustor having a more uniform fluid flow is disclosed. For a combustor end cover, individual nozzle flow rates are determined and nozzles positioned on an end cover such that each nozzle injects substantially the same amount of fluid as an adjacent nozzle. As a result, gas temperature variations within the combustor are reduced and combustion dynamics lowered. For a gas turbine engine utilizing a plurality of combustors, individual end cover flow rates are determined and end covers positioned on each combustor relative to the supply inlet of the engine such that each end cover is supplied with a substantially similar flow rate. Other factors including pressure loss and fluid temperature changes are taken into consideration when determining nozzle and end cover positions.

Abstract: The present invention relates to a gas turbine combustor comprising an air passage to supply air to the inside; and a fuel nozzle which is provided with an injection port to inject fuel and disposed in the air passage, wherein a turbulence producing means adjacent to the injection port of the fuel nozzle is provided in the air passage. Further, the present invention relates to a gas turbine combustor comprising an air passage to supply air to the inside; and a fuel nozzle which is provided with an injection port to inject fuel and disposed in the air passage, wherein a diffuser portion is provided in the air passage, and the diffuser portion causes the cross-sectional area of a part of the air passage positioned in the vicinity of the injection port to be smaller than that of a downstream portion of the air passage positioned downstream from the injection port in the direction of the airflow. Thus, the mixing action of fuel and air can be enhanced, and combustion vibration can be prevented.

Abstract: An improved combination (110) of a premixing chamber (112) and a combustion chamber (111), with low emission of pollutants, for gas turbines running on liquid and/or gas fuel, in which the combustion chamber (111) has a truncated conical end (111a) and is surrounded by a cavity (115) for cooling air (120), the cavity (115) carrying combustion air (120a) to the premixing chamber (112), which has at its inlet apertures or ports (126) which can be constricted according to the quantity of fuel used, and at its outlet a circumferential set of burners (134) to create a corresponding set of additional flames; gas fuel supply means (125) fuel and liquid fuel injection devices (119) are provided in the premixing chamber (112), and a set of liquid fuel injectors (140) is present on the end (111a).

Abstract: The purpose is to improve the mixture ratio of a pre-mixer by a simple arrangement to form a more uniform premixed gases so as to materialize low NOx combustion. Two fuel nozzles disposed circumferentially of a pre-mixer are combined with a single air intake window to make a set, which set is used to produce swirls in a pair, thereby expediting mixing. Further, the inlet window is shaped such that its circumferential width is changed axially of the combustor, thereby changing the strength and size of the swirls to achieve the greatest effect. By reducing both the pre-mixer inlet windows and the partition walls in number, the manufacturing cost can be reduced, and by strengthening and optimizing the swirls, a combustor with superior low NOx performance can be provided, while it is possible to reduce the length of the pre-mixer necessary to obtain the same mixture ratio, leading to a cost reduction.

Abstract: A turbine containing system is disclosed. The system includes an intake section, a compressor section downstream from the intake section, a combustor section having a primary combustion system downstream from the intake section, a secondary combustion system downstream from the primary combustion system, a turbine section, an exhaust section and a load. The secondary combustion system includes an injector for transversely injecting a secondary fuel into a stream of combustion products of the primary combustion system. The injector including a coupling, a wall defining an airfoil shape circumscribing a fuel mixture passage, and at least one exit for communication between said fuel mixture passage and said stream of primary combustion products.

Abstract: A method for operating a gas turbine engine facilitates reducing an amount of emissions from a combustor. The combustor includes a mixer assembly including a pilot mixer, a main mixer, and a centerbody that extends therebetween. The pilot mixer includes a pilot fuel nozzle and a plurality of axial swirlers. The main mixer includes a main swirler and a plurality of fuel injection ports. The method comprises injecting fuel into the combustor through the pilot mixer, such that the fuel is discharged downstream from the pilot mixer axial swirlers, and directing flow exiting the pilot mixer with a lip extending from the centerbody into a pilot flame zone downstream from said pilot mixer.

Abstract: This pilot nozzle has a fuel oil supply pipe disposed at the center of a heat-shielding air layer that is provided along an axial core, and a plurality of atomized-fluid supply paths are disposed in the circumferential direction of a cylinder unit that surrounds the outside of the heat-shielding air layer. The atomized-fluid supply paths and the fuel gas supply paths are disposed alternately and uniformly. Based on this structure, it is possible to take a large thickness for the heat-shielding air layer to a maximum extent in a radial direction. Therefore, it is possible to protect the fuel oil supply pipe disposed at the center, from high temperature at the outside of the pilot nozzle.

Abstract: A combustor (40) for a gas turbine engine is provided with a premix pilot fuel stage (42) in order to reduce the emission of oxides of nitrogen from the engine. An in-service engine may be modified to add the premix pilot fuel stage by delivering premix pilot fuel to a ring manifold (42) for tip-feeding a premix pilot fuel outlet member such as a swirler vane (78) or fuel peg (124). In this manner, complex and expensive components such as the top hat (46), support housing (48) and diffusion pilot burner assembly (44) may be used without modification. Thermal stresses caused by the differential cooling of the ring manifold by the premix pilot fuel (96) are reduced by a heat shield (94) installed within the manifold.

Abstract: A gas turbine combustor includes a side wall, for defining a combustion volume, having upstream and downstream ends, a pilot nozzle, disposed adjacent the upstream end of the side wall, for discharging a pilot fuel to form a diffusion flame in the combustion volume, and a plurality of main nozzles, provided around the pilot nozzles, for discharging a fuel-air mixture to form premixed flames in the combustion volume. Film air is supplied into the combustion volume downstream of the main nozzles along the inner surface of the side wall to reduce the fuel-air ratio in a region adjacent the inner surface of the side wall and to restrain a combustion-driven oscillation in the combustion volume.

Abstract: A fully premixed secondary fuel nozzle assembly for use in a gas turbine combustor having multiple combustion chambers, in which the products of the premixed secondary fuel nozzle assembly are injected into the second combustion chamber for supporting a pilot flame and flame transfer between combustion chambers, is disclosed. The improvement includes the elimination of the pilot fuel circuit, which previously served to establish flame in the second combustion chamber. The secondary fuel nozzle assembly includes at least one first injector extending radially outward from the fuel nozzle body for injecting all fuel from the fuel nozzle to mix with compressed air prior to combustion. The first injector can include a plurality of tubes or an annular manifold circumferentially disposed about the nozzle body. Compressed air is drawn into the nozzle body and passes through holes in an injector plate at the tip region to provide cooling.

Abstract: A gas turbine combustor includes a liquid fuel nozzle for jetting out liquid fuel; a pre-mixture chamber wall provided with the liquid fuel nozzle at a center thereof, having a hollow conical shape gradually spreading in the direction in which the fuel is jetted out, and defining a pre-mixture chamber therein; a plurality of air inlet holes bored through the pre-mixture chamber wall and introducing the combustion air to the pre-mixture chamber such that angles at which the combustion air is introduced to the pre-mixture chamber through the air inlet holes are deflected at least toward the circumferential direction of the pre-mixture chamber wall; and a plurality of gaseous fuel nozzles disposed around the pre-mixture chamber wall in an opposing relation respectively to the plurality of air inlet holes and jetting out gaseous fuel substantially coaxially with axes of the air inlet holes.

Abstract: Manifolds are shaped cross star having curved surfaces inside thereof, and holes are bored in four corners of the manifolds. In mounting a combustor to a casing, oil in the manifolds is transmitted to the holes by way of the curved surfaces. As a result of this, oil is prevented from staying, and coking is prevented from occurring, inside the manifolds.

Abstract: A fuel system for a gas turbine engine having a main burner fuel supply line and a pilot burner fuel supply line, a high pressure pump supplying fuel to the main and pilot burner supply lines in use, a throttle valve controlling the flow of fuel in the main burner supply line, a metering valve controlling the flow of fuel in the pilot burner supply line, and a pressure raising valve between the pilot burners and the metering valve, the pressure raising valve serving to maintain the upstream fuel pressure to a pre-determined amount in excess of the pressure of fuel supplied from the throttle valve to the main burners.

Abstract: A gas turbine combustor has a combustion chamber into which fuel and air are supplied, wherein the fuel and the air are supplied into said combustion chamber as a plurality of coaxial jets.

Abstract: There are provided an injector and an associated method for injecting and mixing gases, comprising a carbonaceous fuel and oxygen, in a combustion chamber of a combustion device. The injector has jets, which can be used to separately inject different combustion fuels. The injector is compatible with combustion devices that inject only gases, for example, a reheater that provides initial combustion in a power generation cycle or a reheater that recombusts a discharged gas from a gas generator and turbine. Further, the injector defines an annular space through which a recycle gas can be injected into the combustion chamber to lower the combustion temperature.

Abstract: There are provided an injector and an associated method for injecting and mixing gases, comprising a carbonaceous fuel and oxygen, in a combustion chamber of a combustion device. The injector has jets, which can be used to separately inject different combustion fuels. The injector is compatible with combustion devices that inject only gases, for example, a reheater that provides initial combustion in a power generation cycle or a reheater that recombusts a discharged gas from a gas generator and turbine. Further, the injector defines an annular space through which a recycle gas can be injected into the combustion chamber to lower the combustion temperature.

Abstract: An injector of a two-headed combustion chamber of a turbomachine has a first feed tube which is connected to an annular injection piece for discharging primary fuel into the combustion chamber. It also has a second feed tube surrounding the first feed tube and connected to a cylindrical endpiece for discharging secondary fuel into said combustion chamber. This endpiece has an annular channel of diameter that is greater than the diameter of the second feed tube and that extends over its entire length. A third tube is provided that surrounds the second tube and that is connected to a tubular separation element which is inserted in the annular channel of the cylindrical endpiece so as to form two annular spaces in which a cooling fluid can flow over 360° all the way to the end of the injector.

Abstract: A gas turbine combustor is provided with a nozzle extension tube having an inclination outward in a diameter direction of a combustor inner cylinder and in a peripheral direction of the combustor inner cylinder. As a result, the premixed gas is transformed to a spiral flow passing into a combustion chamber while turning, i.e., an outward turning flow, thereby sufficiently mixing the premixed gas while the premixed gas is flowing in the combustion chamber.

Abstract: A gas turbine engine (10) includes a plurality of can combustors (19). Each can combustor includes a first stage of burners (46) located at a first radius about the combustor centerline (42) and a second stage of burners (50) located at a second radius greater than the first radius. The second stage of burners may be clocked to an angular position that is not midway between respective neighboring burners of the first stage. Combustion instabilities may be controlled by exploiting variations in combustion parameters created by differential fueling of the two stages.

Abstract: A low emissions combustion method wherein, in an embodiment, a plurality of tangential fuel injectors introduce a fuel/air mixture at the combustor dome end of an annular combustion chamber in two spaced injector planes. Each of the spaced injector planes includes multiple tangential fuel injectors delivering premixed fuel and air into the annular combustor. A generally skirt-shaped flow control baffle extends from the tapered inner liner into the annular combustion chamber downstream of the fuel injector planes. A plurality of air dilution holes in the tapered inner liner underneath the flow control baffle introduce dilution air into the annular combustion chamber while another plurality of air dilution holes in the cylindrical outer liner introduces more dilution air downstream from the flow control baffle.

Abstract: An injector includes a plurality of flat, circular plates which provide fuel delivery and cooling of the injector. Fuel delivery passages in the plates have swirl chambers and spray orifices which are formed by chemical etching. A pair of fuel delivery plates define a fuel cavity therebetween, and include a plurality of radially-outwardly extending spokes, with the spokes from one fuel plate in adjacent, surface-to-surface relation with opposing spokes from the adjacent fuel plate. A fuel passage is defined between each of the opposing spokes, leading from the fuel cavity to a fuel outlet opening at the distal end of each spoke. A fuel tube delivers fuel to the fuel cavity between the plates, from where the fuel is then directed through the outlet openings. Downstream plates shape the fuel into appropriate sprays for ignition. An upstream cooling plate assembly directs air against the upstream fuel plate, and radially outwardly along the spokes of the upstream plate.

Abstract: The purpose is to improve the mixture ratio of a pre-mixer by a simple arrangement to form a more uniform premixed gases so as to materialize low NOx combustion. Two fuel nozzles disposed circumferentially of a pre-mixer are combined with a single air intake window to make a set, which set is used to produce swirls in a pair, thereby expediting mixing. Further, the inlet window is shaped such that its circumferential width is changed axially of the combustor, thereby changing the strength and size of the swirls to achieve the greatest effect. By reducing both the pre-mixer inlet windows and the partition walls in number, the manufacturing cost can be reduced, and by strengthening and optimizing the swirls, a combustor with superior low NOx performance can be provided, while it is possible to reduce the length of the pre-mixer necessary to obtain the same mixture ratio, leading to a cost reduction.

Abstract: A method for operating a gas turbine engine facilitates reducing an amount of emissions from a combustor. The combustor includes a mixer assembly including a pilot mixer, a main mixer, and an annular centerbody extending therebetween. The method comprises injecting at least one of fuel and airflow into the combustor through at least one swirler positioned within the pilot mixer, and injecting fuel into the combustor through at least one swirler positioned within the main mixer, such that the fuel is directed into a combustion chamber downstream from the main mixer.

Abstract: A combustor inner cylinder is disposed inside a combustor outer casing, and a spread flame formation cone and a plurality of premixed flame-formation nozzles are provided inside the combustor inner cylinder. The premixed flame-formation nozzles have sector-shaped outlets and disposed annularly between the combustor inner cylinder and the spread flame formation cone which forms spread combustion flames. Part of the air from a compressor is passed through clearances between the premixed flame-formation nozzles as cooled air and discharged toward a combustion chamber.

Abstract: A gas turbine combustor (10) having a first grouping (64) of pre-mix burners (12, 12′, 12″) having mixing passages (36) that are geometrically different than the mixing passages (38) of a second grouping (66) of pre-mix burners (14, 14′, 14″). The aerodynamic differences created by these geometric differences provide a degree of control over combustion properties of the respective flames (44, 46) produced in a downstream combustion chamber (40) when the two groupings of burners are fueled by separate fuel stages (52, 54). The geometric difference between the fuel passages of the two groupings may be outlet diameter, slope of convergence of the passage diameter, or outlet contour. The fuel injection regions (16, 18) of all of the burners may be identical to reduce cost and inventory complexity. The burners may be arranged in a ring (60) with a center pre-mix burner (68) being identical to burners of either of the groupings.

Abstract: A gas turbine engine combustor can downstream of a pre-mixer has a pre-mixer flowpath therein and circumferentially spaced apart swirling vanes disposed across the pre-mixer flowpath. A primary fuel injector is positioned for injecting fuel into the pre-mixer flowpath. A combustion chamber surrounded by an annular combustor liner disposed in supply flow communication with the pre-mixer. An annular trapped dual vortex cavity located at an upstream end of the combustor liner is defined between an annular aft wall, an annular forward wall, and a circular radially outer wall formed therebetween. A cavity opening at a radially inner end of the cavity is spaced apart from the radially outer wall. Air injection first holes are disposed through the forward wall and air injection second holes are disposed through the aft wall. Fuel injection holes are disposed through at least one of the forward and aft walls.

Abstract: A three-stage lean burn combustion chamber (28) comprises a primary combustion zone (36), a secondary combustion zone (40) and a tertiary combustion zone (44). Each of the combustion zones (36,40,44) is supplied with premixed fuel and air by respective fuel and air mixing ducts (54,70,92). The fuel and air mixing ducts (54,70,92) have a plurality of air injection slots (62,64,76,98) spaced apart transversely to the direction of flow through the fuel and air mixing ducts (54,70,92). The air injection slots (62,64,76,98) extend in the direction of flow through the fuel and air mixing ducts (54,70,92) to the reduce the magnitude of the fluctuations in the fuel to air ratio of the fuel and air mixture supplied into the at least one combustion zone (36,40,44). This reduces the generation of harmful vibrations in the combustion chamber (28).

Abstract: An internal cylinder which has the opening section from which combustion gas is blown out is inserted into the tail cylinder which becomes a flow path of the combustion gas, and is engaged with the tail cylinder, while securing a clearance between the edge of the opening section and the internal wall surface of the tail cylinder. Air compressed with a compressor is jetted from the clearance along the internal wall surface of the tail cylinder, and a film of cooling air is formed on the internal wall surface of the tail cylinder.

Abstract: The present invention relates to an improved multi-point injector for use in a gas turbine engine or other types of combustors. The multi-point fuel injector has a plurality of nozzles arranged in at least two arrays such as concentric rings. The injector further has different fuel circuits for independently controlling the fuel flow rate for the nozzles in each of the arrays. Each of the nozzles include a fluid channel and one or more swirler vanes in the fluid channel for creating a swirling flow within the fluid channel. A method for injecting a fuel/air mixture into a combustor stage of a gas turbine engine is also described. At least one zone has a flame hot enough to stabilize the entire combustor flame.

Abstract: A combustor (40) for a gas turbine engine is provided with a premix pilot fuel stage (42) in order to reduce the emission of oxides of nitrogen from the engine. An in-service engine may be modified to add the premix pilot fuel stage by delivering premix pilot fuel to a ring manifold (42) for tip-feeding a premix pilot fuel outlet member such as a swirler vane (78) or fuel peg (124). In this manner, complex and expensive components such as the top hat (46), support housing (48) and diffusion pilot burner assembly (44) may be used without modification. Thermal stresses caused by the differential cooling of the ring manifold by the premix pilot fuel (96) are reduced by a heat shield (94) installed within the manifold.

Abstract: A pre-mixing burner (10) for a gas turbine engine having improved resistance to flashback. Fuel (32) is supplied to a pre-mixing chamber (24) of the burner from a plurality of fuel outlet openings (34) formed in fuel pegs (36) extending into the flow of air (30) passing through the chamber. The fuel outlet openings are formed to direct the fuel in a downstream direction at an angle (A) relative to the direction of the flow of air past the respective fuel peg. This angle imparts a downstream velocity vector (VD) for increasing the net velocity of the air and a normal velocity vector (VN) for directing the fuel away from the wake (44) formed downstream of the fuel peg. Alternate ones of the fuel outlet openings along a single fuel peg may be formed at respective positive (A) and negative (B) angles with respect to a plane (46) extending along the wake in order to minimize the size of the wake.

Abstract: A gas turbine engine (10) includes a plurality of can combustors (19). Each can combustor includes a first stage of burners (46) located at a first radius about the combustor centerline (42) and a second stage of burners (50) located at a second radius greater than the first radius. The second stage of burners may be clocked to an angular position that is not midway between respective neighboring burners of the first stage. Combustion instabilities may be controlled by exploiting variations in combustion parameters created by differential fueling of the two stages.