Abstract: A diffuser is provided for an exhaust steam housing adjacent a last stage row of buckets fixed to a rotor in a steam turbine, each bucket in the last stage row of buckets having a platform portion and an airfoil portion. The diffuser includes an annular inner diffuser ring and an outer annular diffuser ring defining a flow path for steam exiting the last stage row of buckets in a substantially axial direction at a diffuser inlet and turning substantially ninety degrees to a diffuser outlet. A first portion of the inner annular ring extends in a downstream direction beyond the last stage row of buckets substantially parallel to a center axis of the rotor, the first portion having a length dimension in the downstream direction from a radial center line of the last stage row of buckets in a range of between 0.40 and about 0.70 of a center line radial length from the platform portion to a radially outer tip of any bucket in the last stage row of buckets.

Abstract: A system for removing moisture from a steam/water mixture engaging a stationary component of a steam turbine. The system includes an airfoil located within a flow path of a steam turbine. The airfoil is configured for removing moisture from a steam/water mixture traveling in the flow path. To this end, the airfoil includes a cavity in flow communication with the steam path through at least one inlet and outlet opening, near the leading and trailing edge of the airfoil, respectively. Moisture and steam are extracted from the surface through the inlet openings, the steam and water are separated in the cavity, the separated water flows towards the bottom end, and the dry steam flows through the outlet opening and returns to the steam path. The dry steam blowing out of the trailing edge reduces the size of secondary droplets, and thereby prevents erosion.

Abstract: An airfoil with a tip cover surface treatment for reducing leakage flows, minimizing tip vortex size and penetration into main flow that will improve turbine efficiency. The surface treatment for the airfoil tip covers includes a series of concave shapes, such as grooves or holes. These grooves and holes will cause the leakage flow into separate flow paths within the cavities and generate more resistance to leakage flows through the airfoil tip clearance, thereby reducing the leakage mass flow and weakening tip vortex and its interaction with turbine main flows. The material removed from the tip cover provides the additional benefit of reducing the weight of the tip cover, thereby enhancing blade reliability.

Abstract: A diffuser is provided for an exhaust steam housing adjacent a last stage row of buckets fixed to a rotor in a steam turbine, each bucket in the last stage row of buckets having a platform portion and an airfoil portion. The diffuser includes an annular inner diffuser ring and an outer annular diffuser ring defining a flow path for steam exiting the last stage row of buckets in a substantially axial direction at a diffuser inlet and turning substantially ninety degrees to a diffuser outlet. A first portion of the inner annular ring extends in a downstream direction beyond the last stage row of buckets substantially parallel to a center axis of the rotor, the first portion having a length dimension in the downstream direction from a radial center line of the last stage row of buckets in a range of between 0.40 and about 0.70 of a center line radial length from the platform portion to a radially outer tip of any bucket in the last stage row of buckets.

Abstract: A turbine bucket including a bucket airfoil having an airfoil shape is provided. The airfoil shape has a nominal profile according to the tables set forth in the specification. The X and Y coordinate are smoothly joined by an arc of radius R defining airfoil profile sections at each distance Z. The profile sections at the Z distances are joined smoothly with one another to form a complete airfoil shape. The airfoil profile results in improved efficiency and airfoil loading capability.

Abstract: A turbine bucket including a bucket airfoil having an airfoil shape is provided. The airfoil shape has a nominal profile according to the tables set forth in the specification. The X and Y coordinate are smoothly joined by an arc of radius R defining airfoil profile sections at each distance Z. The profile sections at the Z distances are joined smoothly with one another to form a complete airfoil shape.

Abstract: A system for removing moisture from a steam/water mixture engaging a stationary component of a steam turbine. The system includes an airfoil located within a flow path of a steam turbine. The airfoil is configured for removing moisture from a steam/water mixture traveling in the flow path. To this end, the airfoil includes a cavity in flow communication with the steam path through at least one inlet and outlet opening, near the leading and trailing edge of the airfoil, respectively. Moisture and steam are extracted from the surface through the inlet openings, the steam and water are separated in the cavity, the separated water flows towards the bottom end, and the dry steam flows through the outlet opening and returns to the steam path. The dry steam blowing out of the trailing edge reduces the size of secondary droplets, and thereby prevents erosion.

Abstract: A turbine bucket including a bucket airfoil having an airfoil shape is provided. The airfoil shape has a nominal profile according to the tables set forth in the specification. The X and Y coordinate are smoothly joined by an arc of radius R defining airfoil profile sections at each distance Z. The profile sections at the Z distances are joined smoothly with one another to form a complete airfoil shape.

Abstract: A turbine bucket including a bucket airfoil having an airfoil shape is provided. The airfoil shape has a nominal profile according to the tables set forth in the specification. The X and Y coordinate are smoothly joined by an arc of radius R defining airfoil profile sections at each distance Z. The profile sections at the Z distances are joined smoothly with one another to form a complete airfoil shape. The airfoil profile results in improved efficiency and airfoil loading capability.