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.

Abstract: In a gas turbine bucket having a shank portion, a radial tip portion and an airfoil having leading and trailing edges and pressure and suction surfaces, and an internal fluid cooling circuit, an improvement wherein the internal fluid cooling circuit has a serpentine configuration including plural radial outflow passages and plural radial inflow passages. The radial outflow passages, in one example, are shaped to have aspect ratios of about 3.3 to 1 and Buoyancy Numbers of <0.15 or >0.80.

Abstract: The steam impingement cooling and retrieval system for turbine shrouds includes a plurality of circumferentially spaced housings about a turbine shroud, each housing being divided by an impingement plate defining first and second chambers on opposite sides of the housing. Steam supplied into a first chamber passes through a plurality of apertures formed in the impingement plate into the second chamber for impingement cooling of the shroud surface forming the opposite wall of the housing. Post-impingement steam passes from the compartment into a manifold for flow through and exhaust passage. In one form, a plurality of compartments are formed in the impingement plate. A first set of the plurality of compartments include through apertures for delivering steam from the first chamber into the second chamber.

Abstract: The bucket 10 of a gas turbine includes first and second steam supply passageways 32 and 34 for directing cooling steam radially outwardly along the bucket. Steam return passageways 40, 42 and 44 lie adjacent the trailing edge for returning cooling steam to its source. A shroud is disposed at the bucket tip and has cross-over passages communicating the supply steam from the first and second passageways to the fifth, third and fourth passageways, respectively.

Abstract: The second-stage nozzles include a plurality of stator vanes 10 having first, second, third, fourth and fifth passages 40, 42, 44, 46 and 48, respectively, for cooling the vanes. The first and fourth passages have a steam inlet along an outer sidewall 14 and a junction box 70 along the inner sidewall 12 for returning steam to the second passage 42. The third passage 44 has a contour corresponding to the contour of the leading edge and impingement steam is directed through openings in a partition 52, cooling the leading edge. Steam flows from the third passage 44 directly into the return passage 42 and also into a channel 64 for cooling the inner sidewall 12. Cooling air flows through fifth passage 48 radially inwardly through the inner sidewall 12 into a cavity 72 in the diaphragm 32 for flow axially outwardly into wheel cavities 86 and 88.

Abstract: An apparatus and method for varying the cooling air flow within a gas turbine bucket tip. Each turbomachinery blade contains at least one radial cooling passage located between a hollow interior and an outside of the blade. A transversely-oriented elongate channel connects at least one of the cooling passages with the trailing edge of the blade. Secured within the transversely-oriented channel is a pin which extends into at least one of the radial cooling passages to partially obstruct the cooling fluid flow depending on the needs of the design.