Abstract: A retention system for a plurality of turbine buckets located in respective mating slots in a turbine rotor wheel includes a plurality of first retention slots formed in outer peripheral portions of the turbine wheel, and a plurality of second retention slots formed in wheel mounting portions of the buckets. The first and second retention slots are aligned to form an annular retention slot extending about a peripheral portion of the rotor wheel. A lockwire is located within the annular retention slot, the lockwire having engaged free ends. A plurality of axially-oriented retaining pins are fixed in the rotor wheel to hold the lockwire in the annular retention slot, and various techniques are employed for at least limiting or substantially preventing circumferential rotation of the lockwire within the annular slot.

Abstract: A retention system for a plurality of turbine buckets located in respective mating slots in a turbine rotor wheel includes a plurality of first retention slots formed in outer peripheral portions of the turbine wheel, and a plurality of second retention slots formed in wheel mounting portions of the buckets. The first and second retention slots are aligned to form an annular retention slot extending about a peripheral portion of the rotor wheel. A lockwire is located within the annular retention slot, the lockwire having engaged free ends. A plurality of axially-oriented retaining pins are fixed in the rotor wheel to hold the lockwire in the annular retention slot, and various techniques are employed for at least limiting or substantially preventing circumferential rotation of the lockwire within the annular slot.

Abstract: A stator shroud segment is provided that includes an outer shroud having a leading edge groove and a trailing edge groove; and a plurality of inner shrouds each having a leading edge hook and a trailing edge hook, the leading and trailing hooks of each of the inner shrouds being respectively engaged with the leading and trailing edge grooves of the outer shroud so as to axially and radially lock the inner shrouds to the outer shrouds. At least one of the trailing edge hook of the inner shroud and the trailing edge groove of the outer shroud includes a sloped surface disposed at an angle to an axial direction of the rotor and to a radial direction of the rotor and facing the other of the inner and outer shrouds whereby a radial inward force on the inner shroud is transformed into a force in axial and radial directions to force the inner shroud to tightly seal a radial gap between the inner and outer shrouds.

Abstract: A turbine blade includes a shank portion and an airfoil portion with leading and trailing edges and a radially outer tip. An internal closed-loop cooling circuit is formed within the airfoil portion and includes at least one radial outflow passage and at least one radial inflow passage connected by at least one respective tip turn at the radially outer end of the airfoil portion. At least one tip turn is provided with a single turbulence-enhancement device on an underside of the radially outer tip, projecting into the tip turn.

Abstract: A stator shroud segment is provided that includes an outer shroud having a leading edge groove and a trailing edge groove; and a plurality of inner shrouds each having a leading edge hook and a trailing edge hook, the leading and trailing hooks of each of the inner shrouds being respectively engaged with the leading and trailing edge grooves of the outer shroud so as to axially and radially lock the inner shrouds to the outer shrouds. At least one of the trailing edge hook of the inner shroud and the trailing edge groove of the outer shroud includes a sloped surface disposed at an angle to an axial direction of the rotor and to a radial direction of the rotor and facing the other of the inner and outer shrouds whereby a radial inward force on the inner shroud is transformed into a force in axial and radial directions to force the inner shroud to tightly seal a radial gap between the inner and outer shrouds.

Abstract: A turbine blade includes a shank portion and an airfoil portion with leading and trailing edges and a radially outer tip. An internal closed-loop cooling circuit is formed within the airfoil portion and includes at least one radial outflow passage and at least one radial inflow passage connected by at least one respective tip turn at the radially outer end of the airfoil portion. At least one tip turn is provided with a single turbulence-enhancement device on an underside of the radially outer tip, projecting into the tip turn.

Abstract: A turbine blade includes a shank portion and an airfoil portion with leading and trailing edges and a radially outer tip. An internal closed-loop cooling circuit is formed within the airfoil portion and includes at least one radial outflow passage and at least one radial inflow passage connected by at least one respective tip turn at the radially outer end of the airfoil portion. At least one tip turn is provided with a single turbulence-enhancement device on an underside of the radially outer tip, projecting into the tip turn.

Abstract: A turbine nozzle is disclosed having a nozzle blade with an inner band, wherein the inner band has a region to receive a nozzle cover plate and at least one raised angel wing seal land section proximate a side of the recess; the nozzle cover plate is seated on the region of the inner band and the plate has a raised angel wing seal land section aligned with the at least one raised angel wing seal land section on the inner band, wherein the perimeter of the nozzle cover is welded to the inner band; a slot in the angel wing seal land is adjacent the perimeter of the cover plate, and the slot is filled with an insert after the cover plate is welded to the nozzle inner band.

Abstract: A pair of hollow elongated leg sections are disposed in one or more of the nozzle vane cavities of a nozzle stage of a gas turbine. Each leg section has an outer wall portion with apertures for impingement-cooling of nozzle wall portions in registration with the outer wall portions. The leg sections may be installed into the cavity separately and support rods support and maintain the leg sections in spaced relation, whereby the designed impingement gap between the outer wall portions of the leg sections and the nozzle wall portions is achieved. The support rods are secured to the inner wall portions of the leg sections by welding or brazing.