Abstract: A turbine disc assembly is provided. The turbine disc assembly includes a first rotor disc, a second rotor disc, and a spacer disc coupled between the first and second rotor discs along an axis to define a plenum. The spacer disc has an inner surface with a radius from the axis. A first cooling channel defined between the first rotor disc and the spacer disc is in flow communication with the plenum. The second rotor disc includes a deflector having a deflection surface positioned within the plenum such that the deflection surface is oriented towards the first cooling channel at an acute angle relative to the radius of the inner surface of the spacer disc.

Abstract: A turbine disc having a radius and a circumference is provided. The turbine disc includes a central aperture and a plurality of cooling channels circumferentially spaced about the central aperture such that the cooling channels are in flow communication with the central aperture. Each of the cooling channels has a radially inner end, a radially outer end, and a lengthwise axis that is curved between the radially inner end and the radially outer end.

Abstract: A turbine disc having a radius and a circumference is provided. The turbine disc includes a central aperture and a plurality of cooling channels circumferentially spaced about the central aperture such that the cooling channels are in flow communication with the central aperture. Each of the cooling channels has a radially inner end, a radially outer end, and a lengthwise axis that is curved between the radially inner end and the radially outer end.

Abstract: A turbine disc assembly is provided. The turbine disc assembly includes a first rotor disc, a second rotor disc, and a spacer disc coupled between the first and second rotor discs along an axis to define a plenum. The spacer disc has an inner surface with a radius from the axis. A first cooling channel defined between the first rotor disc and the spacer disc is in flow communication with the plenum. The second rotor disc includes a deflector having a deflection surface positioned within the plenum such that the deflection surface is oriented towards the first cooling channel at an acute angle relative to the radius of the inner surface of the spacer disc.

Abstract: The present application provides a diffuser for an exhaust hood of a steam turbine. The diffuser may include a first end adjacent to a last bucket and a second end downstream of a steam guide and adjacent to a bearing cone. An exhaust flow path extends therethrough. The second end may include an axial extension enlarging the exhaust flow path.

Abstract: A method of assembling a sealing assembly for use in a turbomachine includes providing a rotatable element that includes an end portion with a plurality of grooves partially extending circumferentially about a portion of an outer surface of the end portion of the rotatable element. The method also includes providing a stationary portion that includes an upper section and a lower section. The method further includes inserting at least a portion of the end portion of the rotatable element into the lower section. The method also includes coupling the upper section to the lower section, thereby defining a rotor shaft cavity. The end portion of the rotatable element at least partially extends through the rotor shaft cavity, thereby defining a clearance between the end portion of the rotatable element and the stationary portion.

Abstract: An exhaust diffuser for a turbine includes an inlet configured to receive exhaust gas from a last stage bucket of the turbine and an exhaust gas guide surface configured to guide the exhaust gas. A curvature of the guide surface comprises a first angle with respect to an axis of the turbine and a ratio of a guide surface axial length to the active length of the last stage bucket which is between about 0.45 to 0.70. A method of diffusing exhaust of a turbine includes energizing a boundary layer along a curved exhaust flow guide surface of an exhaust diffuser with over tip leakage of a last stage bucket of the turbine.

Abstract: Tip shrouds on last stage buckets for condensing steam turbines may create significant blockage and form a vortex at the wall of the steam guide of the diffuser, causing the steam flow to separate from the wall of the steam guide. Vortex formation reduces the effective flow area for the remaining fluid to diffuse, causing poor recovery. An inward radial depression is provided of a predetermined depth and distance along an outer steam guide, which redirects the tip leakage flows slightly downward, reducing a shroud blockage effect. This deflection assists the main flow in rejoining the steam guide, thereby making the diffuser more effective.

Abstract: A seal is provided for preventing axial leakage through a radial gap between a stationary structure and a rotating structure. The radial gap is defined by an inner radial surface opposing an outer radial surface across the radial gap. The seal includes at least one land disposed on one of the inner radial surface and outer radial surface. At least one first tooth and at least one second tooth project from the other of the radial surfaces. The second tooth is shorter than the first tooth. At least one of the first tooth and second tooth, is configured to extend at an angle upstream. This angle is defined between a radial surface from which the first or second tooth projects and an upstream surface of the same tooth. The angle is less than or equal to about 80 degrees.

Abstract: An exhaust diffuser including an outer flow guide surface and an inner flow guide surface defining an inlet, a first collection chute having an outlet in fluid communication with the inlet, the first collection chute operative to diffuse a flow of a fluid, a second collection chute having an outlet in fluid communication with the inlet, the second collection chute operative to diffuse the flow of the fluid, and the outer flow guide surface and the inner flow guide surface are operative to guide and direct the flow of the fluid to the first collection chute and the second collection chute.

Abstract: An exhaust arrangement for a turbine is provided having an inner turbine casing, a condenser, an exhaust arrangement structure, and a bearing cone. The inner turbine casing includes a plurality of last stage buckets. A steam flow passes through the inner turbine casing and out of the plurality of last stage buckets. The condenser for receives the steam flow. The exhaust arrangement structure has a diffuser, a lower section and an upper section. The lower section has an exhaust section. The lower section receives the steam flow from the last stage buckets of the inner turbine casing through the diffuser and guides the steam flow out of the exhaust section in a direction generally towards the condenser. The upper section has a receiving section and a guiding section.

Abstract: A turbine exhaust diffuser for use adjacent a last stage row of buckets fixed to a turbine rotor includes an annular inner diffuser ring and an annular outer diffuser ring defining a flow path for steam exiting a last stage row of buckets in a first substantially axial direction at a diffuser inlet, and turning substantially ninety degrees to a diffuser outlet. The outer diffuser ring has a curved steam guide surface extending between the diffuser inlet and the diffuser outlet including a first portion extending away from the diffuser inlet and a second portion extending to said diffuser outlet, the second portion shaped to extend beyond vertical and back toward the diffuser inlet so as to establish a flow component in a second opposite axial direction. The second portion is also provided with a plurality of turbulators to minimize flow separation along the steam guide surface.

Abstract: A method of assembling a sealing assembly for use in a turbomachine includes providing a rotatable element that includes an end portion with a plurality of grooves partially extending circumferentially about a portion of an outer surface of the end portion of the rotatable element. The method also includes providing a stationary portion that includes an upper section and a lower section. The method further includes inserting at least a portion of the end portion of the rotatable element into the lower section. The method also includes coupling the upper section to the lower section, thereby defining a rotor shaft cavity. The end portion of the rotatable element at least partially extends through the rotor shaft cavity, thereby defining a clearance between the end portion of the rotatable element and the stationary portion.

Abstract: The present application provides a diffuser for an exhaust hood of a steam turbine. The diffuser may include a first end adjacent to a last bucket and a second end downstream of a steam guide and adjacent to a bearing cone. An exhaust flow path extends therethrough. The second end may include an axial extension enlarging the exhaust flow path.

Abstract: A labyrinth seal system is disclosed, including a stationary component having a plurality of radially inwardly projecting, axially spaced teeth extending therefrom; and a rotor having a plurality of radially outwardly projecting, axially spaced protrusions, each protrusion having a low pressure side and a high pressure side, wherein the low pressure side of at least one protrusion extends farther in a radial direction than the high pressure side.

Abstract: A seal is provided for preventing axial leakage through a radial gap between a stationary structure and a rotating structure. The radial gap is defined by an inner radial surface opposing an outer radial surface across the radial gap. The seal includes at least one land disposed on one of the inner radial surface and outer radial surface. At least one first tooth and at least one second tooth project from the other of the radial surfaces. The second tooth is shorter than the first tooth. At least one of the first tooth and second tooth, is configured to extend at an angle upstream. This angle is defined between a radial surface from which the first or second tooth projects and an upstream surface of the same tooth. The angle is less than or equal to about 80 degrees.

Abstract: In a rotary machine such as a steam turbine, pressurized fluid flows through a series of stationary and rotary components. Minimizing leakage flow of the fluid enhances the operation and efficiency of the machine. At least one rotor land has a groove formed thereon to generate a vortex as the fluid passes over. The vortex resists the axial flow of the fluid, which reduces the leakage flow.

Abstract: Tip shrouds on last stage buckets for condensing steam turbines may create significant blockage and form a vortex at the wall of the steam guide of the diffuser, causing the steam flow to separate from the wall of the steam guide. Vortex formation reduces the effective flow area for the remaining fluid to diffuse, causing poor recovery. An inward radial depression is provided of a predetermined depth and distance along an outer steam guide, which redirects the tip leakage flows slightly downward, reducing a shroud blockage effect. This deflection assists the main flow in rejoining the steam guide, thereby making the diffuser more effective.

Abstract: An exhaust diffuser including an outer flow guide surface and an inner flow guide surface defining an inlet, a first collection chute having an outlet in fluid communication with the inlet, the first collection chute operative to diffuse a flow of a fluid, a second collection chute having an outlet in fluid communication with the inlet, the second collection chute operative to diffuse the flow of the fluid, and the outer flow guide surface and the inner flow guide surface are operative to guide and direct the flow of the fluid to the first collection chute and the second collection chute.