Abstract: A heat recovery steam generator (HRSG) is coupled to a gas turbine engine that is configured to combust a fuel in air to produce shaft power and a flow of exhaust gases including oxides of nitrogen (NOx). The HRSG includes at least one duct burner for heating the exhaust gases and at least one NOx reduction element coupled downstream from the at least one duct burner and configured to facilitate reducing an amount of NOx in the exhaust gases that are channeled into the at least one NOx reduction element.

Abstract: A method of fabricating a component for a gas turbine engine is provided. The method includes applying a bond coat to at least a portion of the component, applying a dense vertically cracked (DVC) thermal barrier coating to at least a portion of the bond coat using a spray mechanism positioned a first distance from the component, and overlying at least a portion of the DVC thermal barrier coating with a soft coat thermal barrier coating using a spray mechanism that is positioned a second distance away from the component, wherein the second distance is greater than the first distance to facilitate adherence of the soft coating thermal barrier coating to the DVC thermal barrier coating.

Abstract: A method of fabricating a component for a gas turbine engine is provided. The method includes applying a bond coat to at least a portion of the component, applying a dense vertically cracked (DVC) thermal barrier coating to at least a portion of the bond coat using a spray mechanism positioned a first distance from the component, and overlying at least a portion of the DVC thermal barrier coating with a soft coat thermal barrier coating using a spray mechanism that is positioned a second distance away from the component, wherein the second distance is greater than the first distance to facilitate adherence of the soft coating thermal barrier coating to the DVC thermal barrier coating.

Abstract: A pattern for improving aerodynamic performance of a turbine includes a material disposed in a pattern at a base surface of a turbine shroud such that the material is capable of abradable contact with a tip portion of a turbine bucket. The pattern includes a first plurality of ridges disposed at the base surface such that a first portion of the first plurality of ridges corresponding to a back portion of the turbine bucket is oriented at a first angle with respect to an axis of rotation of the turbine bucket. Each ridge of the first plurality of ridges has a first sidewall and a second sidewall having a first end and a second end. The first ends of the first and second sidewalls extend from the base surface. The first and second sidewalls slope toward each other with substantially equal but opposite slopes until meeting at the second ends of respective first and second sidewalls defining a centerline and a top portion of the ridge.

Abstract: An article of manufacture pattern for improving aerodynamic performance of a turbine including an abradable material capable of abradable contact. The abradable material is disposed in a pattern. The pattern includes a first plurality of ridges disposed at a base surface of the turbine. Each ridge of the first plurality of ridges has a first sidewall and a second sidewall having a first end and a second end. The first ends of the first and second sidewalls extend from the base surface. The first and second sidewalls slope toward each other with substantially equal but opposite slopes until meeting at the second ends of respective first and second sidewalls defining a centerline and a top portion of the ridge.

Abstract: In turbomachinery, first and second flowpaths coupled to stages of the compressor flow cooling medium at different temperatures and pressures to components of the turbine. An ejector is provided in the first flowpath for suctioning flow from the second flowpath and combining the two flows for delivery to a component of the turbine at a temperature and pressure intermediate the temperature and pressure of the first and second flows. A flow sensor, flow controller and throttling valve are interposed in the motive flowpath, the exit flowpath or the suction flowpath relative to the ejector for controlling the flow through the ejector.

Abstract: In turbomachinery, first and second flowpaths coupled to stages of the compressor flow cooling medium at different temperatures and pressures to components of the turbine. An ejector is provided in the first flowpath for suctioning flow from the second flowpath and combining the two flows for delivery to a component of the turbine at a temperature and pressure intermediate the temperature and pressure of the first and second flows. A flow sensor, flow controller and throttling valve are interposed in the motive flowpath, the exit flowpath or the suction flowpath relative to the ejector for controlling the flow through the ejector.

Abstract: Leakage flows through seals are used to cool components of a turbine downstream of the seals. At certain seal locations, the leakage flows are restricted to the extent that cooling of downstream components cannot be effected by the leakage flows. The cooling air leakage flow is augmented by extracting bleed air from different stages at different temperatures from a compressor and combining the extracted flows in an ejector to provide a flow having a temperature intermediate the temperatures of the extracted flow streams for augmenting the leakage flow to cool the component. The ejector thus uses high extraction air to entrain lower temperature extraction air to lower the ejector exit air temperature, reducing the magnitude of air required to cool the downstream component and enhancing the effectiveness of the advanced seal.

Abstract: A gas turbine operational strategy is provided for the optimization of ISO-Day rated performance. The invention is realized by setting the nominal operating line equal to or slightly below the operating limit line, so that ISO full load performance is maximized. Thus, the first stage turbine nozzle throat area is sized such that, without inlet bleed heat addition, and at Base-Load pressure ratio and firing temperature, the compressor operates within its operational limits on a ISO day. As ambient conditions change, levels of inlet bleed heat and firing temperature are controlled and the inlet guide vane angle is set whereby the nominal operating line is equal to or slightly below the operating limit line.

Abstract: Brush seals are employed on steam turbine rotors without the risk of causing thermal rotor bowing and without compromising the sealing performance. In one form, a groove in the rotor has an insert in frictional contact with the brush seal. The non-uniform distribution of heat due to frictional contact between the brush seal and proud portions of the rotor is dissipated within the insert such that adjoining rotor portions are substantially uniformly heated without causing thermal bow. In a further form, a groove or grooves are provided in the rotor surface adjacent to the brush seal and maintain non-uniform heat distribution locally in the rotor without causing thermal bow of the rotor. In another form, a land projects radially outwardly of the rotor surface in contact with the brush seal. The non-uniform distribution of heat due to frictional contact between proud portions of the land and the brush seal dissipates into a uniform distribution of heat in the rotor proper to avoid thermal bowing.

Abstract: Brush seals are retrofitted into existing turbine labyrinth seal rings to create a fail-safe seal design at locations wherever labyrinth seals are currently used, including interstage shaft seals, rotor end seals, bucket (or blade) tip seals and spill strips. Brush seals, per se, when used in place of labyrinth seals, can result in considerable span reductions of steam turbines, or machines with more turbine stages for a given span. Application to end packings results in the potential elimination of gland sealing/exhauster systems. Brush seal life can be improved by retrofitting brush segments to labyrinth seal segments that are either spring-backed, or use pressure loads to obtain design clearances only after steady state operating conditions are achieved. The brush seals are provided with backing plates shaped like labyrinth teeth, resulting in a fail-safe design.