Abstract: Apparatus for reducing air mass flow through the compressor in a single shaft gas turbine engine having an extended operating range including part load conditions, to provide low emissions combustion. The apparatus includes one or more nozzles positioned for injecting compressed air into the inlet region of the compressor. The nozzles are oriented to direct the compressed air tangentially to, and in the same angular direction as, the direction of rotation to create a swirl in the inlet air flow to the compressor inducer. The apparatus also includes conduits in flow communication between the compressor diffuser and the nozzles, one or more valves operatively connected to control the flow of compressed air from the diffuser to the nozzles, and a controller operatively connected to the valves to cause compressed air flow to the nozzles during operation at part load conditions.

Abstract: Apparatus for reducing air mass flow through the compressor in a single shaft gas turbine engine having an extended operating range including part load conditions, to provide low emissions combustion. The apparatus includes one or more nozzles positioned for injecting compressed air into the inlet region of the compressor. The nozzles are oriented to direct the compressed air tangentially to, and in the same angular direction as, the direction of rotation to create a swirl in the inlet air flow to the compressor inducer. The apparatus also includes conduits in flow communication between the compressor diffuser and the nozzles, one or more valves operatively connected to control the flow of compressed air from the diffuser to the nozzles, and a controller operatively connected to the valves to cause compressed air flow to the nozzles during operation at part load conditions.

Abstract: Apparatus for channeling combustion gases to a turbine in a gas turbine engine. The engine has a compressor for providing compressed air, a combustor for combusting fuel with the compressed air to provide combustion gases, and a radial inflow turbine having an inlet configured to receive the combustion gases. The turbine is rotatable about an axis for expanding the combustion gases to produce work. The apparatus includes a subassembly of plurality of nozzle guide vanes fixed between a pair of spaced apart, ring-shaped sidewalls. A pair of spaced apart supports is configured to position the subassembly therebetween, concentric with the axis, and adjacent the turbine inlet. The apparatus further includes a plurality of bolt assemblies extending axially through the pair of supports, apertures in the sidewalls, and holes in the guide vanes.

Abstract: A compact, single shaft gas turbine gas generator uses a high pressure ratio dual-entry single stage centrifugal compressor, can combustors, and a radial inflow turbine with the compressor configured to achieve an overall pressure ratio of about 12:1 or greater and Mach Numbers less than or equal to about 1.4. The radial inflow turbine is configured to provide an expansion ratio of about 4:1 to about 5:1, to provide partially expanded combustion gases to a free-power turbine or an expansion nozzle, in a work-producing engine configuration. A ball bearing assembly in front of the compressor is used in conjunction with a thrust piston assembly to take up turbine thrust load, while a radial tilt pad bearing assembly is used in front of the turbine. A collector with scroll-shaped sector portions collects compressed air from an annular vaned diffuser, and respective crossover ducts channel the collected diffused compressed air from each sector portion to a plenum feeding can combustors.

Abstract: A compact, single shaft gas turbine gas generator uses a high pressure ratio dual-entry single stage centrifugal compressor, can combustors, and a radial inflow turbine with the compressor configured to achieve an overall pressure ratio of about 12:1 or greater and Mach Numbers less than or equal to about 1.4. The radial inflow turbine is configured to provide an expansion ratio of about 4:1 to about 5:1, to provide partially expanded combustion gases to a free-power turbine or an expansion nozzle, in a work-producing engine configuration. A ball bearing assembly in front of the compressor is used in conjunction with a thrust piston assembly to take up turbine thrust load, while a radial tilt pad bearing assembly is used in front of the turbine. A collector with scroll-shaped sector portions collects compressed air from an annular vaned diffuser, and respective crossover ducts channel the collected diffused compressed air from each sector portion to a plenum feeding can combustors.

Abstract: A gas turbine engine with a single stage combustor includes an external premixer to provide premixed fuel/compressed air to the combustor as well as compressed air for dilution; and an automatic controller to provide feedback control of the compressed air flow and fuel flow to the premixer in accordance with actual power versus power demand. The fuel/compressed air mixture is combusted in a combustor and the combustion gases and dilution air are expanded in a turbine. The engine further includes a bleed valve under control of the controller for diverting sufficient compressed dilution air past the turbine to induce increased fuel flow and compressed air flow to the premixer for delivery to, and combustion of, the combustor to compensate for the power deficit due to the bled air, to provide selected minimum premixer exit velocities during engine operation.

Abstract: Apparatus for premixing fuel and air to provide a fuel/air mixture includes a mixing tube configured for receiving fuel and air, a mixing tube axis, and a mixing tube exit for discharging a fuel/air mixture. The apparatus further includes a mixture valve associated with the mixing tube exit and including inner and outer valve members that define an exit flow area. The defined exit flow area includes at least two segmented, substantially opposed area portions with respect to angular position about the mixing tube axis for directing the mixture flow, and at least one of the inner and outer valve members is movable relative to the other of said valve members to selectively vary the defined exit flow area with respect to time. In a gas turbine gas generator or engine application, a separate controllable combustion air valve can be used with a fuel valve to provide controlled fuel/air ratios for the mixture.

Abstract: Apparatus for premixing fuel and air to provide a fuel/air mixture includes a mixing tube configured for receiving fuel and air, a mixing tube axis, and a mixing tube exit for discharging a fuel/air mixture. The apparatus further includes a mixture valve associated with the mixing tube exit and including inner and outer valve members that define an exit flow area. The defined exit flow area includes at least two segmented, substantially opposed area portions with respect to angular position about the mixing tube axis for directing the mixture flow, and at least one of the inner and outer valve members is movable relative to the other of said valve members to selectively vary the defined exit flow area with respect to time. In a gas turbine gas generator or engine application, a separate controllable combustion air valve can be used with a fuel valve to provide controlled fuel/air ratios for the mixture.

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: An air valve assembly for use with a premixer for a gas turbine engine module. The air valve assembly includes a valve disk and a support plate having a valve aperture in which the valve disk is disposed for rotation, the support plate having aligned first and second shaft apertures through opposing support plate ends that define an axis of rotation of the valve disk. The assembly also has a first shaft having one end section rotatably supported in the first aperture and having another end section connected to the valve disk; a second shaft having one end section rotatably supported in and extending through the second shaft aperture and with a bearing end terminating outside the support plate, and also having another end section connected to the valve disk.

Abstract: A low emissions combustor system for a gas turbine includes a combustion chamber liner defining a combustion space for combusting a homogeneous fuel and compressed air mixture received through an inlet to produce combustion gases for delivery to the turbine through a liner exit. The liner has both principal dilution ports and secondary dilution ports adjacent and upstream of the liner exit, and a premixer assembly operatively connected to the liner for providing the fuel/air mixture. The premixer assembly includes an air valve for controlling the fuel/air ratio of the mixture. The combustor system also includes a compressed air supply plenum upstream of, and in flow communication with, the air valve. A shroud partly surrounds the liner and provides a cooling channel between the plenum and the principal dilution ports.

Abstract: An annular combustor system is disclosed in use with a radial turbine-type gas turbine gas generator, the system having an annular housing defining a single stage combustor, an external fuel/air premixer system having a mixing chamber and a fuel valve under the control of a controller, to provide a preselected lean fuel/air ratio mixture for introduction to the combustion zone of the annular housing. A separate compressed air valve under the control of the controller can optionally be included. Compressed air conduits are used to channel a portion of the total compressed air flow to the premixer and the remainder to the dilution zone of the combustor, and a fuel conduit is used to deliver all of the fuel to the premixer. Convection cooling of the annular housing is accomplished using compressed air without diluting the fuel air ratio in the combustion zone.

Abstract: An annular combustor system is disclosed in use with a radial turbine-type gas turbine gas generator, the system having an annular housing defining a single stage combustor, an external fuel/air premixer system having a mixing chamber and a fuel valve under the control of a controller, to provide a preselected lean fuel/air ratio mixture for introduction to the combustion zone of the annular housing. A separate compressed air valve under the control of the controller can optionally be included. Compressed air conduits are used to channel a portion of the total compressed air flow to the premixer and the remainder to the dilution zone of the combustor, and a fuel conduit is used to deliver all of the fuel to the premixer. Convection cooling of the annular housing is accomplished using compressed air without diluting the fuel air ratio in the combustion zone.

Abstract: A generally annular combustor system has a chamber with an annular chamber portion and a plurality of can-like chamber portions protruding from the annular chamber portion. An external fuel/air premixer is associated with each can chamber portion to provide a mixture with a desired (generally lean) fuel/air ratio tangentially through the can sidewall. A first portion of the total compressed air flows to the premixers, a second portion enters the combustion chamber through ports which, for can chamber volumes sufficient for complete combustion, can be located in the can chamber portion proximate the connection between the can portion and the annular portion. The premixer associated with each can chamber portion preferably includes a venturi and a fuel nozzle for spraying liquid fuel or gas into the venturi inlet to provide a fully premixed fuel/air mixture.

Abstract: A generally annular combustor system has a combustion chamber with an annular chamber portion and a plurality of can-like chamber portions protruding tangentially from the annular chamber portion, the portions collectively defining a single stage combustor. An external fuel/air premixer is associated with each can chamber portion to provide a preselected, nominally constant, lean fuel/air ratio mixture. A portion of the total compressed air flows to the premixers and the remaining portion is ducted to convection cooling passageways and finally admitted as dilution air proximate the exit of the annular chamber portion. When the fuel/power setting is changed, the combustion air flow is automatically set by varying the position of air valves associated with each premixer to achieve the desired combustible mass flow. In one embodiment, the air valve controls the dilution air flow rate from the plenum region and thus, indirectly, the combustion air flow rate.

Abstract: An annular combustor system has an annular housing defining a single stage combustor, an external fuel/air premixer system to provide a preselected, nominally constant lean fuel/air ratio mixture for introduction to the combustion zone of the annular housing. Compressed air conduits channel a portion of the total compressed air flow to the premixer and the remainder to the dilution zone of the combustor. Convection cooling of the annular housing and the turbine shroud is accomplished using essentially the remainder portion of the compressed air without diluting the fuel air ratio in the combustion zone. The premixer includes a venturi, and a fuel nozzle for spraying fuel into the venturi inlet along the venturi axis to provide admission of the fully premixed fuel/air mixture.

Abstract: An annular combustor system is disclosed in use with a radial turbine-type gas turbine engine module, the system having an annular housing defining a single stage combustor, an external fuel/air premixer system having a mixing chamber and a compressed air valve and a fuel valve both under the control of a controller, to provide a preselected lean fuel/air ratio mixture for introduction to the combustion zone of the annular housing. Compressed air conduits are used to channel a portion of the total compressed air flow to the premixer and the remainder to the dilution zone of the combustor, and a fuel conduit is used to deliver all of the fuel to the premixer. Convection cooling of the annular housing is accomplished using compressed air without diluting the fuel air ratio in the combustion zone.

Abstract: An annular combustor system is disclosed in use with a radial turbine-type gas turbine engine module, the system having an annular housing defining a single stage combustor, an external fuel/air premixer system having a mixing chamber and a compressed air valve and a fuel valve both under the control of a controller, to provide a preselected lean fuel/air ratio mixture for introduction to the combustion zone of the annular housing. Compressed air conduits are used to channel a portion of the total compressed air flow to the premixer and the remainder to the dilution zone of the combustor, and a fuel conduit is used to deliver all of the fuel to the premixer. Convection cooling of the annular housing is accomplished using compressed air without diluting the fuel air ratio in the combustion zone.

Abstract: An annular combustor system is disclosed in use with a radial turbine-type gas turbine engine module, the system having an annular housing defining a single stage combustor, an external fuel/air premixer system having a mixing chamber and a compressed air valve and a fuel valve both under the control of a controller, to provide a preselected lean fuel/air ratio mixture for introduction to the combustion zone of the annular housing. Compressed air conduits are used to channel a portion of the total compressed air flow to the premixer and the remainder to the dilution zone of the combustor, and a fuel conduit is used to deliver all of the fuel to the premixer. Convection cooling of the annular housing is accomplished using compressed air without diluting the fuel air ratio in the combustion zone.

Abstract: A gas generator having a double entry low pressure centrifugal compressor, a single entry high pressure centrifugal compressor and a radial inflow turbine positioned coaxially and coupled for interdependent rotation by a single shaft assembly for the double entry compressor mounted to the generator frame using a plurality of rigid hollow cross-over ducts which also carry diffused compressed air to the high pressure compressor, where the single shaft assembly uses two shaft portions connected by an expansible coupling having a helical spline torque transmitting device to allow the double entry compressor rotor to "follow" compressor housing axial position changer and to maintain a close running clearance despite thermal expansion in the structure between the low pressure (LP) and high pressure (HP) compressor portions of the gas generator.