Abstract: A process for retrofitting an industrial gas turbine engine of a power plant where an old industrial engine with a high spool has a new low spool with a low pressure turbine that drives a low pressure compressor using exhaust gas from the high pressure turbine, and where the new low pressure compressor delivers compressed air through a new compressed air line to the high pressure compressor through a new inlet added to the high pressure compressor. The old electric generator is replaced with a new generator having around twice the electrical power production. One or more stages of vanes and blades are removed from the high pressure compressor to optimally match a pressure ratio split. Closed loop cooling of one or more new stages of vanes and blades in the high pressure turbine is added and the spent cooling air is discharged into the combustor.

Abstract: A small gas turbine engine with a ceramic turbine to allow for higher turbine inlet temperatures, where a metallic compressor is secured to a ceramic shaft extending from a ceramic turbine to form a single piece ceramic shaft and turbine, where a threaded nut secures a split ring retainer on the compressor end of the ceramic shaft. A hollow thrust runner is compressed between the compressor disk and the turbine disk by the threaded nut to secure rotor together. A centering spring forms a tight fit between the metallic thrust runner and the ceramic shaft on the turbine side.

Abstract: A gas turbine engine for an aircraft such as a UAV includes a compressor connected to a turbine with a combustor to produce a hot gas stream. The rotor is supported by two radial foil bearings. An axial thrust bearing assembly is positioned between the compressor disk and the turbine disk and includes an axial thrust bearing radial disk extending from a hollow axial tube. Compressed air is bled off from the compressor and passed into an axial thrust balance chamber to provide the axial thrust balance for the rotor. The compressed air from the thrust bearing chamber then flows through both of the radial foil bearings for cooling, is collected in and around the hollow tube, and then discharged into the inlet of the turbine. An orifice can be adjusted to meter and control a pressure occurring in the thrust balance chamber.

Abstract: A system and method for testing a combustor or other component of a large industrial gas turbine engine. A test facility for testing a gas turbine engine component includes a storage reservoir, a heat exchanger (13) with a first fluid flow passage connected to the storage reservoir and a second fluid flow passage, a combustor (18) connected to the second fluid flow passage of the heat exchanger (13), a hot gas stream from the combustor flowing within the second fluid flow passage, and a test component of a gas turbine engine connected to the second fluid flow passage of the heat exchanger (13). The compressed air from the storage reservoir (11) passes through the heat exchanger (13) first fluid flow passage and is preheated from the hot gas stream passing through the second fluid flow passage, and the preheated compressed air from the heat exchanger (13) passes into the test component for testing.

Abstract: A process for retrofitting an electric power plant that uses two 60 Hertz large frame heavy duty industrial gas turbine engines to drive electric generators and produce electricity, where each of the two industrial engines can produce up to 350 MW of output power. The process replaces the two 350 MW industrial engines with one twin spool industrial gas turbine engine that is capable of producing at least 700 MW of output power. Thus, two prior art industrial engines can be replaced with one industrial engine that can produce power equal to the two prior art industrial engines.

Abstract: An axial thrust load sensor for an axial thrust foil bearing used in a small gas turbine engine, the axial thrust load sensor having a axial thrust foil bearing plate and an intermediate washer plate and a load sensor plate arranged face to face to form the load sensor. The load sensor plate has three pedestals on a front side and three pedestals on a back side so that all six pedestals alternate at equal spacing. Next to each pedestal is a strain gauge connected to a controller. The controller regulates a supply of cooling air to the axial thrust bearing in order to control a thrust balance.

Abstract: A turbocharged gas turbine engine with an electric generator to provide electrical power for an aircraft (e.g., UAV) with multiple propulsor fans each driven by an electric motor, where the engine includes a low spool that drives a main fan and a high spool that drives a high speed electric generator. The low pressure compressor supplies low pressure air to an inlet of the high pressure compressor. A row of stator vanes in the high pressure turbine is cooled using cooling air bled off from the low pressure compressor outlet that is passed through an intercooler and a boost compressor, where the spent vane cooling air is discharged into the combustor. The low pressure turbine and the two compressors each include a variable inlet guide vane to control the power level of the engine. Bypass flow from the main fan is used to cool hot parts of the engine.

Abstract: A process for retrofitting an industrial gas turbine engine of a power plant where an old industrial engine with a high spool has a new low spool with a low pressure turbine that drives a low pressure compressor using exhaust gas from the high pressure turbine, and where the new low pressure compressor delivers compressed air through a new compressed air line to the high pressure compressor through a new inlet added to the high pressure compressor. The old electric generator is replaced with a new generator having around twice the electrical power production. One or more stages of vanes and blades are removed from the high pressure compressor to optimally match a pressure ratio split. Closed loop cooling of one or more new stages of vanes and blades in the high pressure turbine is added and the spent cooling air is discharged into the combustor.

Abstract: An industrial gas turbine engine with a high spool and a low spool in which low pressure compressed air is supplied to the high pressure compressor, and where a portion of the low pressure compressed air is bled off for use as cooling air for hot parts in the high pressure turbine of the engine. Annular bleed off channels are located in the LPC diffuser. The bleed channels bleed off around 15% of the core flow and pass the bleed off air into a cooling flow channel that then flows into the cooling circuits in the turbine hot parts.

Abstract: A turbine with a variable inlet guide vane assembly in which the vane airfoils extend between inner and outer buttons, and in which a center of rotation of the airfoil is located aft of an aerodynamic center of pressure of the airfoil. The trailing edge of the airfoil extends into both of the buttons such that no gap is formed between the airfoil trailing edge region and a static part of the turbine during movement of the airfoil from an opened position to a closed position.

Abstract: A system and method for testing a combustor or other component of a large industrial gas turbine engine. A test facility for testing a gas turbine engine component includes a storage reservoir, a heat exchanger (13) with a first fluid flow passage connected to the storage reservoir and a second fluid flow passage, a combustor (18) connected to the second fluid flow passage of the heat exchanger (13), a hot gas stream from the combustor flowing within the second fluid flow passage, and a test component of a gas turbine engine connected to the second fluid flow passage of the heat exchanger (13). The compressed air from the storage reservoir (11) passes through the heat exchanger (13) first fluid flow passage and is preheated from the hot gas stream passing through the second fluid flow passage, and the preheated compressed air from the heat exchanger (13) passes into the test component for testing.

Abstract: An apparatus and a process for converting a twin spool aero gas turbine engine to an industrial gas turbine engine, where the fan of the aero engine is removed and replaced with an electric generator, a power turbine is added that drives a low pressure compressor that is removed from the aero engine, variable guide vanes are positioned between the high pressure turbine and the power turbine, and a low pressure compressed air line is connected between the outlet of the low pressure compressor and an inlet to the high pressure compressor, where a hot gas flow produced in the combustor first flows through the high pressure turbine, then through the low pressure turbine, and then through the power turbine.

Abstract: An industrial gas turbine engine with a high spool and a low spool in which low pressure compressed air is supplied to the high pressure compressor, and where a portion of the low pressure compressed air is bled off for use as cooling air for hot parts in the high pressure turbine of the engine. Annular bleed off channels are located in the LPC diffuser. The bleed channels bleed off around 15% of the core flow and pass the bleed off air into a cooling flow channel that then flows into the cooling circuits in the turbine hot parts.

Abstract: A method of repairing a worn carburized surface on a sprag clutch comprising the steps of: grinding the worn carburized surface of the sprag clutch to prepare the surface for metallurgical bonding; place the worn carburized surface in a PVD Cathodic Arc chamber; preheat the worn carburized surface to remove moisture and provide for a good metallurgical bonding surface; reverse sputter clean the surface to remove any surface oxide; apply a first coating layer using the PVD process to a maximum thickness; change the coating macro topology by polishing the coated surface; apply a second coating layer using the PVD process to a maximum thickness; and, grind or polish the coating to a desired dimension.

Abstract: A cooling circuit for a trailing edge region of a turbine airfoil where the trailing edge is relatively thin, the cooling circuit having a series of aftward flowing channels alternating with a series of forward flowing cooling channels, and a turn channel at the trailing edge of the airfoil where the aftward flowing channels flow into the forward flowing channels in order to keep the airfoil thin and to provide cooling to the thin trailing edge. Spanwise extending cooling supply channels and cooling return channels are connected to the aftward and forward flowing channels and positioned to allow for a thinner airfoil.

Abstract: A part formed using an metal additive manufacturing process such as a turbine airfoil with an oversized feature such as an oversized hole, where the oversized hole is filled with a preform having a shape of a normal sized hole and secured within the part using a braze or weld material, and where the preform is removed to leave within the part the normal sized hole. The preform is made of a refractory material that can be removed from the part by exposure to oxygen.

Abstract: A spiral cooling system for cooling an aft turbine casing of a gas turbine engine. The gas turbine engine includes a turbine casing having a fore end and an aft end, a star bearing support member supporting a bearing housing and including a plurality of struts each mounted to an aft flange at the aft end of the turbine casing. The turbine casing includes an outer casing wall and an inner casing wall at the aft end defining an airflow plenum therebetween that receives cooling air at an input end opposite to the aft flange. The spiral cooling system includes a plurality of fins secured to an inside surface of the outer wall and being spaced from the inner wall that directs the airflow from the input end in a circular manner around the plenum to an output end of the plenum.

Abstract: A process for retrofitting an electric power plant that uses two 60 Hertz large frame heavy duty industrial gas turbine engines to drive electric generators and produce electricity, where each of the two industrial engines can produce up to 350 MW of output power. The process replaces the two 350 MW industrial engines with one twin spool industrial gas turbine engine that is capable of producing at least 700 MW of output power. Thus, two prior art industrial engines can be replaced with one industrial engine that can produce power equal to the two prior art industrial engines.

Abstract: An apparatus and a process for converting a twin spool aero gas turbine engine to an industrial gas turbine engine, where the fan of the aero engine is removed and replaced with an electric generator, a power turbine is added that drives a low pressure compressor that is removed from the aero engine, variable guide vanes are positioned between the high pressure turbine and the power turbine, and a low pressure compressed air line is connected between the outlet of the low pressure compressor and an inlet to the high pressure compressor, where a hot gas flow produced in the combustor first flows through the high pressure turbine, then through the low pressure turbine, and then through the power turbine.

Abstract: A large frame heavy duty industrial gas turbine engine that can produce twice the power as a conventional single spool industrial engine, and can operate at full power during a hot day. The industrial engine includes a high spool that directly drives an electric generator at a synchronous speed of the electric power grid, a low spool with a low pressure turbine that drives a low pressure compressor from the exhaust gas from the high pressure turbine, where the low pressure compressor supplies compressed air to the high pressure compressor. Variable inlet guide vane assemblies are used in the low pressure turbine and the low pressure compressor so that the high spool can operate at full power even during a hot day. The low spool is designed to operate at a higher speed than at the normal temperature conditions so that a high mass flow can be produced for the high spool during the hot day conditions.