Abstract: A fuel system for a turbine engine for reducing CO emissions caused during fuel staging processes while the turbine engine operates at reduced loads. The fuel system may include a first premix injector assembly and a second premix injector assembly, each formed from one or more injectors. In at least one embodiment, the first premix injector includes four injectors assembled into two pairs, and the second premix injector includes four injectors assembled into two pairs. The two pairs of the second premix injector assembly may be positioned between the two pairs forming the first premix injector assembly, thereby reducing the interface between fueled and unfueled areas, which reduces CO emissions.

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 method of operating 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. Fuel injection staging sequences are disclosed that create the conditions necessary to provide stable combustion and reduced emissions at multiple load conditions.

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: A lean premix burner for a gas turbine having at least one fuel supply ring 4 fitted with primary fuel nozzles 8 and additional secondary fuel nozzles 9, and a method of operation for this lean premix burner.

Abstract: Method and device (1) for supplying fuel to a combustion chamber that includes at least one main injector (3) and at least one pilot injector (2). The device includes a fuel tank (4), a line system (5) coupled from the fuel tank to the injectors (2, 3), a pump (6) for pumping fuel from the tank to the injectors, and a first regulator valve (7) for regulating the flow of fuel in a first line (8) in the system which is connected to the pilot injector (2). The device further includes a second regulator valve (9) for regulating the flow of fuel through a second line (10) in the system, which is connected to the pilot injector (2). The second regulator valve (9) is designed to regulate a substantially smaller flow than the first regulator valve (7).

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: A gas turbine combustor apparatus comprising plural combustors and plural fuel supply systems realizes a combustion of a lean and uniform pre-mixture in each of the combustors to thereby enable to reduce NOx generation. Flow regulating valves 29, 30 are provided in fuel supply systems 23, 24, respectively, that supply combustors 25, 26 with fuel. Pressure gauges 31, 32 are provided in the fuel supply systems 23, 24, respectively, in front of inlets of the combustors 25, 26. The flow regulating valves 29, 30 are controlled so that pressures measured by the pressure gauges 31, 32 become the same.

Abstract: A fuel delivery system for a gas turbine engine combustor, the combustor having at least two fuel injectors of substantially the same design. All the fuel injectors are in flow communication with a first fuel supply via a first manifold, and some but not all of the injectors are in flow communication with a second fuel supply via a second manifold. During normal operation of the gas turbine engine combustor fuel is supplied to all of the fuel injectors via the first manifold. However, during predetermined engine operating conditions a second fuel supply is used to supply fuel flow in those fuel injectors in flow communication with the second manifold.

Abstract: A fuel system having an ecology valve controlling liquid flow through a retention passage when pressurized liquid is passed through the valve is presented. The retention passage winds between the valve outlet and a cavity such that no matter which way the valve is oriented gravity alone is unable to drain liquid from the cavity to the outlet. The ecology valve serves to suction fuel from fuel nozzle passages upon engine shutdown. Fuel is temporarily stored in the cavity and the retention passage. The ecology valve also provides a fuel splitting function for providing a port geometry determined split between fuel nozzles in the fuel system.

Abstract: A multiplex injector system comprising an injector head, a first fuel path located in the injector head, and a first set of injector tips located in the injector head and in fluid communication with the first fuel path. The first set of injector tips includes at least one first injector tip. The multiplex injector further includes a second fuel path located in the injector head and a second set of injector tips located in the injector head and in fluid communication with the second fuel path. The second set of injector tips includes at least one second injector tip. A flow of fuel in each of the first and second fuel paths can be selectively controlled to control the flow of fuel through the first and second sets of injector tips.

Abstract: A fuel flow dividing ecology valve conveys fuel from a fuel source to at least a secondary gas turbine engine intake manifold during engine operation and withdraws fuel therefrom upon cessation of engine operation. The valve includes a flow dividing valve portion having an inlet coupled to the fuel source and an outlet coupled to the secondary manifold. The valve also includes an ecology valve portion controlled by the fuel pressure differential between the fuel source and the flow restricting inlet. The ecology valve portion includes a housing with a movable piston disposed therein. The piston defines, in conjunction with the housing, a variable volume chamber for withdrawing fuel from the engine intake manifolds. When the engine is de-energized, the piston moves from a first position toward a second position thereby purging the manifolds of fuel.

Abstract: A fuel injector assembly for dispensing fuel in the combustion chamber of a gas turbine engine, includes in one embodiment an elongated, multi-layered, convoluted nozzle feed strip having an internal passage for directing fuel through the length of the strip from the inlet end to an outlet end; and a cylindrical, multi-layered fuel dispensing nozzle unitary with the feed strip and fluidly connected to the outlet end of the feed strip for dispensing the fuel. The multi-layered feed strip and nozzle allow complex porting of fuel circuits through the injector. The internal fluid passages through the feed strip and nozzle are formed by etching. In another embodiment, the feed strip can be used for directing fuel from the manifold to one or more fuel injectors.

Abstract: A combustor for a gas turbine engine includes a fuel delivery system that uses circumferential fuel staging. The fuel delivery system includes a plurality of fuel supply rings and a backpurge sub-system. The fuel supply rings are arranged concentrically at various radial distances to supply fuel to a combustor through a plurality of combustor manifolds and pigtails. The backpurge system uses high temperature and high pressure combustor air to purge fuel from non-flowing fuel supply rings, combustor pigtails, and combustor manifolds. Additionally, the fuel delivery system includes at least two orifices to minimize pressure decays during filling stages.

Abstract: A fuel supply control system for a gas turbine includes a plurality of solenoid valves. The solenoid valves are energized in a timing sequence with a phase relationship designed to achieve a desired fuel flow. In one example, one solenoid valve is associated with a primary portion of a fuel manifold while at least two other solenoids are associated with a secondary portion of the manifold. A controller that energizes the solenoids to achieve the desired fuel flow can receive feedback information regarding turbine performance to make adjustments to the solenoid operation to bring the turbine performance closer to a desired level.

Abstract: A method and apparatus for converting single multiphase fluid flow into plural multiphase fluid flows having substantially uniform composition and flow properties. A manifold comprises an enclosure having an inlet and an inner surface perpendicular to the inlet such that the incident angle of input flow impacts the surface to form a stagnation point whereby an intermediate flow is deflected along the surface substantially symmetrically outward from the stagnation point and channeled to a plurality of parallel fluid outlets connected to the enclosure. The distance between the stagnation point and the plurality of outlets is selected to maintain substantially equivalent fluid pressures and uniform flow rates at the outlets. A preferred embodiment of the manifold channels the intermediate flow between two walls forming a triangular shaped nozzle directing the flow from the stagnation point to the base of the triangle for communication of electrolyte to a metal-based fuel cell through the plurality of outlets.

Abstract: An oil supply system for a gas turbine comprises an oil feeding device, a water feeding device and a blow-off device, The oil feeding device comprises a fuel distributor connected to an oil supply line and delivering oil through primary and secondary oil conduits and to the combustion chambers of the turbine. The water feeding device comprises a water supply line connected to a distributor delivering primary and secondary water through conduits to the combustion chambers. The blow-off device comprises an air supply line split into two supply branch lines, two closed circular pipes connected to the supply branch lines by connection valves, and primary and secondary air conduits connected to the closed circular pipes for delivering air to the nozzles of the combustion chamber. To ensure a gentle oil firing operation of the gas turbine meeting the requirement of low emission values, the oil and water feeding devices comprise a secondary distributor connected to the oil and water, respectively.

Abstract: A gas turbine combustor apparatus comprising plural combustors and plural fuel supply systems realizes a combustion of a lean and uniform pre-mixture in each of the combustors to thereby enable to reduce NOx generation. Flow regulating valves 29, 30 are provided in fuel supply systems 23, 24, respectively, that supply combustors 25, 26 with fuel. Pressure gauges 31, 32 are provided in the fuel supply systems 23, 24, respectively, in front of inlets of the combustors 25, 26. The flow regulating valves 29, 30 are controlled so that pressures measured by the pressure gauges 31, 32 become the same.

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 (76, 78, 80, 92). Secondary fuel injectors (106) and two secondary fuel manifolds (105A, 105B) supply fuel into different circumferential sectors, halves, of the secondary fuel and air mixing duct (80). The secondary fuel manifolds (105A, 105B) have secondary fuel valves (107A, 107B) which supply a greater proportion of fuel to the secondary fuel manifold (105A) than the secondary fuel manifold (105B) so that there is circumferential biasing of fuel in the secondary combustion zone (40). This circumferential biasing of fuel in the secondary combustion zone (40) reduces the generation of harmful pressure oscillations in the combustion chamber (28).

Abstract: A fuel delivery system for a gas turbine engine combustor, the combustor having at least two fuel injectors of substantially the same design. All the fuel injectors are in flow communication with a first fuel supply via a first manifold, and some but not all of the injectors are in flow communication with a second fuel supply via a second manifold. During normal operation of the gas turbine engine combustor fuel is supplied to all of the fuel injectors via the first manifold. However, during predetermined engine operating conditions a second fuel supply is used to supply fuel flow in those fuel injectors in flow communication with the second manifold.

Abstract: A fuel system for a gas turbine engine having a fuel conduit carried within an outer containment member for receiving and containing leakage from the fluid conduit. The fuel conduit includes an end that carries an elongated ferrule that has a first, enlarged head end to receive a connecting nut and a second end for receiving an end of the fuel conduit and for spacing the end of the fuel conduit from the head end of the ferrule. The ferrule has a body portion intermediate the first and second ends that has a tapered outer surface so that the body portion has thicker side wall adjacent the head end than that adjacent the second end.

Abstract: A fuel control system for supplying metered quantities of fuel from a fuel supply (11), through a fuel pump (13), a metering valve (15) and a pressurizing valve (17) to a plurality of engine fuel manifolds (31a, 31b, 33) includes an ecology valve (43) for withdrawing fuel from the engine fuel manifolds (31a, 31b, 33) during cessation of engine operation and for returning fuel to the engine fuel manifolds (31a, 31b, 33) to be burned during normal engine operation. The ecology valve (43) includes a valve housing (44) having a plurality of ecology ports (50, 52, 54) adapted to be coupled to corresponding ones of the engine fuel manifolds (31a, 31b, 33) and a control port (46) adapted to be connected to a corresponding control port (45) of the fuel pressurizing valve (17).

Abstract: A gas turbine engine combustor includes outer and inner liners joined together at an annular dome. Outer and inner air swirlers and cooperating fuel injectors are mounted in two rows in the combustor dome. The fuel injectors are joined to a common fuel manifold for simultaneously channeling fuel thereto over an operating range from idle to full power for reducing exhaust emissions.

Abstract: A fuel nozzle system for use in a combustor utilized in a combustion turbine for reducing nitrogen oxides and other pollutants including an annular fuel distribution manifold separately mounted away from a diffusion nozzle, said annular manifold having a plurality of fuel emitting passages or holes disposed along the downstream side of the manifold, said manifold being mounted in a position away from the diffuser nozzle body to allow air to stream around the manifold on all sides allowing for a thorough mixture of fuel and air around the annular manifold for better premixing in the combustion chamber. In an alternate embodiment, the diffusion nozzle is replaced by a pilot flame nozzle that is supplied with both air and fuel through a premix air and fuel chamber to a pilot flame nozzle which is used to sustain combustion in the secondary chamber. The use of a pilot flame nozzle that has a fuel and air mixture is believed to reduced NOx emissions.

Abstract: An improved bulkhead for dual fuel industrial and aeroengine gas turbines, that may be formed by one or more bulkhead elements. Each element has a fuel-air channel, having an inlet for introducing air and an outlet for exiting a fuel-air mixture. Each element further includes at least one manifold for introducing a liquid or a gaseous fuel into the fuel-air channel. The channel and the manifold are formed by a plurality of etched layers of macrolaminate or platelet material. Each element may further include an air cooling channel for cooling the backside of the bulkhead. The bulkhead may be used in can and in annular combustors.

Abstract: A fuel control system for supplying metered quantities of fuel from a fuel supply (11), through a fuel pump (13), a metering valve (15) and a pressurizing valve (17) to a plurality of engine fuel manifolds (31a, 31b, 33) includes an ecology valve (43) for withdrawing fuel from the engine fuel manifolds (31a, 31b, 33) during cessation of engine operation and for returning fuel to the engine fuel manifolds (31a, 31b, 33) to be burned during normal engine operation. The ecology valve (43) includes a valve housing (44) having a plurality of ecology ports (50, 52, 54) adapted to be coupled to corresponding ones of the engine fuel manifolds (31a, 31b, 33) and a control port (46) adapted to be connected to a corresponding control port (45) of the fuel pressurizing valve (17).

Abstract: A combustor for a gas turbine engine includes a fuel delivery system that uses circumferential fuel staging. The fuel delivery system includes a plurality of fuel supply rings and a backpurge sub-system. The fuel supply rings are arranged concentrically at various radial distances to supply fuel to a combustor through a plurality of combustor manifolds and pigtails. The backpurge system uses high temperature and high pressure combustor air to purge fuel from non-flowing fuel supply rings, combustor pigtails, and combustor manifolds. Additionally, the fuel delivery system includes at least two orifices to minimize pressure decays during filling stages.

Abstract: A fuel delivery system for fuel nozzle staging includes a gas circuit and a fuel circuit. Each circuit includes a first manifold and a second manifold. The fuel delivery system delivers a first gas and a first fuel to a gas turbine engine during initial operation through the first manifold connected within each respective gas circuit. As the gas turbine engine reaches a predetermined operational speed, staging valves permit the fuel delivery system to also deliver the first gas and the first fuel to the gas turbine engine through the second manifold of each respective gas circuit.

Abstract: A fuel delivery system for fuel nozzle staging includes a gas circuit and a fuel circuit. Each circuit includes a first manifold and a second manifold. The fuel delivery system delivers a first gas and a first fuel to a gas turbine engine during initial operation through the first manifold connected within each respective gas circuit. As the gas turbine engine reaches a predetermined operational speed, staging valves permit the fuel delivery system to also deliver the first gas and the first fuel to the gas turbine engine through the second manifold of each respective gas circuit.

Abstract: A gas turbine engine for generating electricity having low NOx emissions that includes a turbine system linearly and axially connected by a power shaft to a compressor section and having a combustion section mounted vertically relative to the turbine section and the compressor section. The combustion system includes a plurality of individual combustors mounted in a circular or annular array around the upper cap or dome of the combustion system, each of said combustors being a dual mode, two-stage, emitting low levels of NOx. Each combustor exhausts its combustion gases into a common central plenum chamber that is vertically oriented relative to the turbine engine centerline. The plenum provides the hot gases to the turbine blades through an annular chamber 360 degrees around the shaft. The gas turbine engine vertical combustion system provides for a highly efficient, low nitric oxide emissions while allowing for uniform mixing of the combusting gases powering the turbine system.

Abstract: A fuel injector for use in a gas turbine engine includes an inlet stem with a bore formed therein and an insert disposed in the bore. The insert has a cavity formed therein for receiving a fuel filter. The use of the insert allows the upstream end of the inlet stem to be connected to a fuel manifold with a double seal fitting.

Abstract: A fuel control system for supplying metered quantities of fuel from a fuel supply (11), through a fuel pump (13), a metering valve (15) and a pressurizing valve (17) to a plurality of engine fuel manifolds (31a, 31b, 33) includes an ecology valve (43) for withdrawing fuel from the engine fuel manifolds (31a, 31b, 33) during cessation of engine operation and for returning fuel to the engine fuel manifolds (31a, 31b, 33) to be burned during normal engine operation. The ecology valve (43) includes a valve housing (44) having a plurality of ecology ports (50, 52, 54) adapted to be coupled to corresponding ones of the engine fuel manifolds (31a, 31b, 33) and a control port (46) adapted to be connected to a corresponding control port (45) of the fuel pressurizing valve (17).

Abstract: A fuel nozzle system for use in a combustor utilized in a combustion turbine for reducing nitrogen oxides and other pollutants including an annular fuel distribution manifold separately mounted away from a diffusion nozzle, said annular manifold having a plurality of fuel emitting passages or holes disposed along the downstream side of the manifold, said manifold being mounted in a position away from the diffuser nozzle body to allow air to stream around the manifold on all sides allowing for a thorough mixture of fuel and air around the annular manifold for better premixing in the combustion chamber.

Abstract: A process for controlling a system for generating electricity which contains at least two compressors and two microturbines. Compressed gas from a pressure vessel is supplied to the first microturbine, and thereafter the pressure within the pressure vessel is measured. If the pressure is below a specified value, a first compressor is caused to operate to feed compressed gas to the pressure vessel. Thereafter, as the system needs require, a second compressor and, optionally, a third compressor is caused to furnish compressed gas to the pressure vessel. If the system pressure within the pressure vessel is too high, the third compressor is shut down and, if necessary, the second compressor and the first compressor are then sequentially shut down.

Abstract: A fluid manifold (41) comprises two annular chambers (42 and 46) in flow series and having a barrier (45) therebetween. A fluid is fed into the first larger annular chamber (42) and circulates circumferential therethrough before being passed through a plurality of apertures (44) in the barrier (45) to the second smaller annular chamber (46). The fluid circulates circumferentially through the second chamber (46) in the opposite direction prior to its discharge through apertures (50) in a final barrier (48). The apertures (50) in the final barrier (48) decelerate the fluid discharging therefrom to enhance mixing of air with the fluid downstream of the manifold (41).

Abstract: A premixer for a combustor system has a venturi-type mixing tube with a flow axis, an inlet adjacent one axial mixing tube end, and a nozzle assembly at the opposite axial mixing tube end. The mixing tube inlet is flow connected to a source of compressed air and a source of fuel, and the mixing tube is connected to combustion chamber, an annular or can-type liner and an inlet, and the nozzle assembly extends into the combustion chamber and has at least one port for distributing the fuel/air mixture within a single stage combustion zone. In a preferred configuration, a pair of premixers are located at diametrically opposed positions on an annular combustion chamber, and the venturi axes are both radially disposed and axially inclined with respect to the combustion chamber axis. A single, centrally located, cylindrical air valve controls compressed air flow to both premixers through a manifold and distribution conduits.

Abstract: Lean premixed combustion of a hydrocarbon fuel and air is combined with lean direct injection of hydrocarbon fuel and carrier fluid such as air or inert gas or a mixture of air and inert gas into a combustor downstream of the premixed reaction zone in order to achieve extremely low levels of emissions of oxides of nitrogen at the high combustor exit temperatures required by advanced heavy duty industrial gas turbines. One or more premixing fuel nozzles are used to supply a lean mixture of hydrocarbon fuel and air to the main or primary reaction zone of a gas turbine combustor. This lean fuel/air mixture has an adiabatic flame temperature below the temperature that would result in substantial thermal NOx formation.

Abstract: A distributor for supplying burners of a gas turbine with fuel, air and coolant. Prior art distributors contain a combination of ring lines and tie lines, over which the fuel is distributed to individual burners. It is very complicated and expensive to replace defective components, and in some cases the entire apparatus has to be dismantled to do so. The distributor of the invention has two or more modules, depending on the number of burners, which are assembled from distributor units and regulating units in such a way that they can be taken apart again. For each burner, at least one regulating unit is provided, from which at least one supply line for the fuel, air and coolant extends to the burner.

Abstract: A combustor for a gas turbine having first and second passages for pre-mixing primary fuel and air supplied to a primary combustion zone. The flow of fuel to the first and second pre-mixing passages is separately regulated using a single annular fuel distribution ring having first and second row of fuel discharge ports. The interior portion of the fuel distribution ring is divided by a baffle into first and second fuel distribution manifolds and is located upstream of the inlets to the two pre-mixing passages. The annular fuel distribution ring is supplied with fuel by an annular fuel supply manifold, the interior portion of which is divided by a baffle into first and second fuel supply manifolds. A first flow of fuel is regulated by a first control valve and directed to the first fuel supply manifold, from which the fuel is distributed to first fuel supply tubes that direct it to the first fuel distribution manifold.

Abstract: A gas-turbine combustor (1) provided with a plurality of premix burners (2-a, 2-b) and a diffusion burner (8) and capable of varying the number of the operating premix burners according to the variation of load thereon comprises fuel pipes (3-a, 3-b, 9) connected to the burners, flow control valves (4-a, 4-b, 10) placed respectively in the fuel pipes, a pressure control valves (6, 12) placed in fuel pipes (5, 11), a fuel distribution setting device (14) for controlling the respective openings of the flow control valves according to load, and a pressure ratio setting device (15) for controlling the respective openings of the pressure control valves when the condition of the flow control valves is changed.

Abstract: A dual fuel injection system for a low Nox combustor in which separate gaseous and liquid fuel manifolds are integrally joined to form manifold assemblies. Each manifold assembly extends circumferentially around the inlet of an annular fuel and air mixing passage. The gaseous fuel manifolds have a number of gas discharge ports spaced around their circumferences. The liquid fuel manifolds have a number of fuel nozzles spaced around their circumferences. The gaseous fuel discharge ports and liquid fuel nozzles are oriented so as to inject fuel into the annular passages in a manner that will facilitate mixing of the fuel and air. Separate gaseous and liquid fuel supply tubes are connected to each manifold.

Abstract: A positive displacement pump supplies a low lubricity liquid fuel through a main supply line to the combustors of a turbine. A pressure transducer and a flow meter are provided in the main fuel supply line. The fuel is supplied to a pressure compensated fuel delivery valve which divides the fuel equally among the combustors and affords pressure compensation. A controller is responsive to the pressure in the main fuel supply line to control a bypass pressure valve to supply fuel in the main supply line at a predetermined pressure. The controller also controls the total volume of fuel flow rate through the pressure compensated fuel delivery valve responsive to the flow meter. In another form, a centrifugal pump supplies fuel to the pressure compensated fuel delivery valve. A controller responsive to the flow meter in the main supply line controls the total fuel flow rate to the valve which divides the fuel equally among the combustors at equal flow rates.

Abstract: A gas turbine augmentor fuel manifold unit is provided which includes a plurality of fuel manifolds, each having a plurality of feed tubes, and at least one wear resistant clamp for clamping the feed tubes. The wear resistant clamp includes first and second wear sleeves, first and second clamp members, and a fastener. The wear sleeves are disposed between the clamp members and the tubes to minimize wear therebetween. The first wear sleeve, which is fixed to one of the feed tubes, includes a plurality of retaining tabs to limit the travel of the first and second clamp members.

Abstract: A gas turbine augmentor fuel manifold is provided which includes a hollow body, a plurality of fuel valves and a cleansing port disposed in the hollow body, and apparatus for selectively admitting fuel into the hollow body. The hollow body has a forward surface and an aft surface. When the apparatus for selectively admitting fuel into the hollow body is in an off position, core gas flowing past the hollow body enters the cleansing port and purges the interior of the hollow body of residual fuel and fuel residue, thereby cleaning the hollow body.

Abstract: In a gas turbine having a plurality of combustors, each having an annular array of outer fuel nozzles arranged about a center axis, an improved construction is provided wherein each combustor has a center nozzle located on the center axis. Various methods of operating the improved combustor are also disclosed.

Abstract: A staged fuel system for a gas turbine engine in which the main burners are supplied with fuel through fluid pressure actuated, servo-controlled valves. All pilot and main burners are supplied from a single manifold. However, fuel flow to the main burners is controlled by the servo-valves which are controlled by pressure in a servo-manifold fed with fuel tapped from a high pressure region of the fuel system. Thus, a simple variable control valve on the outlet of the servo-manifold is able to control fuel staging.

Abstract: A fuel injection system for a gas trubine engine combustion chamber comprises at least one pilot fuel injector having a fuel discharge passage communicated to the combustion chamber and at least one secondary fuel injector having a fuel discharge passage communicated to the combustion chamber and a fuel purging passage communicated to a higher pressure region upstream of the combustion chamber. A fuel flow control device supplies metered fuel flow to the pilot fuel injector under all regimes of engine operation and to the secondary fuel injector under certain, intermittent regimes of engine operation requiring fuel flow above a selected level. A shuttle valve is movable to a first position to provide fuel flow communication between the fuel control device and the fuel discharge passage of the secondary fuel injector for fuel injection to the combustion chamber.

Abstract: A fuel manifold staging valve is provided for use with aircraft engines. A first set of fuel nozzles is associated with a primary manifold, and a second set of fuel nozzles is associated with a secondary manifold. The valve opens on the basis of a constant ratio of fuel flow divided by compressor discharge pressure. The valve detects fuel flow by sensing the pressure drop across the fuel nozzles. This pressure drop is biased by a spring and compared to the compressor discharge pressure. When the ratio is correct for the geometry of the valve, the valve begins to open, allowing fuel to flow to the secondary manifold and associated fuel nozzles.

Abstract: A fuel control system for a gas turbine engine having a plurality of burner manifolds, comprising a spill valve for spilling excess fuel from a high pressure fuel supply line and a plurality of control arrangements, each of which is arranged to control fuel flow rate to a respective one of the manifolds and comprises a metering valve and a regulator for regulating the pressure drop across the metering valve, the spill valve having a cylinder containing a piston which is movable to close the spill valve and each of the regulators having a valve for connecting the cylinder of the spill valve to high pressure fuel when the pressure drop across the metering valve is less than a predetermined value.

Abstract: A combustor for a gas turbine includes a diffusion flame combustion zone, a catalytic combustion zone and a post-catalytic combustion zone. At start-up or low-load levels, fuel and compressor discharge air are supplied to the diffusion flame combustion zone to provide combustion products for the turbine. At mid-range operating conditions, the products of combustion from the diffusion flame combustion zone are mixed with additional hydrocarbon fuel for combustion in the presence of a catalyst in the catalytic combustion zone. Because the fuel/air mixture in the catalytic reactor bed is lean, the combustion reaction temperature is too low to produce thermal NO.sub.x. Under high-load conditions, a lean direct injection of fuel/air is provided in a post-catalytic combustion zone where auto ignition occurs with the reactions going to completion in the transition between the combustor and turbine section.