Abstract: In a gas turbine having a compressor discharge casing, a cooling circuit diverts compressor discharge air toward a high pressure packing (HPP) circuit. The cooling circuit includes an inlet pipe that receives compressor discharge air. One or several cooled cooling air pipes are in fluid communication with the inlet pipe via a pipe manifold, which distributes the discharge air across the cooled cooling air pipes. A seal is disposed upstream of an entrance to the HPP circuit to limit flow into the HPP circuit, and a second seal is disposed downstream of the HPP circuit at turbine wheelspace to limit ingestion and thus the purge flow air required. The circuit serves to reduce required purge flow in the HPP circuit so that an amount of compressor discharge air can be put back to the main flow path, thereby improving turbine performance.

Abstract: A coating and method for overcoating a TBC on a component used in a high-temperature environment, such as the combustor section of an industrial gas turbine. The coating defines the outermost surface of the component and is formed of at least two layers having different compositions. An inner layer of the coating contains alumina in a first silica-containing matrix material that is free of zinc titanate. An outer layer of the coating contains alumina, a glass material, and zinc titanate in a second silica-containing matrix material. The outer layer of the coating has a surface roughness of not greater than three micrometers Ra and forms the outermost surface of the component. The coating reduces the component temperature by reducing the convective and radiant heat transfer thereto.

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: A coating and method for overcoating a TBC on a component used in a high-temperature environment, such as the combustor section of an industrial gas turbine. The coating defines the outermost surface of the component and is formed of at least two layers having different compositions. An inner layer of the coating contains alumina in a first silica-containing matrix material that is free of zinc titanate. An outer layer of the coating contains alumina, a glass material, and zinc titanate in a second silica-containing matrix material. The outer layer of the coating has a surface roughness of not greater than three micrometers Ra and forms the outermost surface of the component. The coating reduces the component temperature by reducing the convective and radiant heat transfer thereto.

Abstract: A method of applying a profiled abradable coating onto a substrate in which an abradable ceramic coating composition is applied to a metal substrate using one or more coating application techniques to produce a defined ceramic pattern without requiring a separate web or grid to be brazed onto the substrate. The invention is particularly designed to withstand the higher operating temperatures encountered with the stage 1 section of 7FA+e gas turbines to allow for increased coating life without significant deterioration in structural or functional integrity. Typically, the grid pattern coating begins approximately 0.431? after the leading edge of the shroud, and ends approximately 1.60? before the trailing edge of the shroud. In the case of diamond-shaped patterns, the grid pattern will be about 0.28? long and 0.28? wide, with an overall thickness of about 0.46.