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 steam turbine includes a diffuser that has a bearing cone and an inner plate of a steam guide that define a passage through which steam flows. An outer plate is disposed with respect to the inner plate such that an opening is located between the inner and outer plates. At least one hole is located in the inner plate. A water tube is disposed in the opening, the water tube having water flowing therethrough which condenses at least a portion of a flow of steam flowing in the passage thereby creating at least a partial vacuum within the opening. The vacuum creates a suction effect through the at least one hole in the inner plate that can cause at least a portion of the flow of steam in the passage to attach itself to an inner surface of the inner plate.

Abstract: An exhaust hood for an axial steam turbine that includes a radial channel, downstream from the normal flow pattern. The radial channel guides the exhaust steam flow in upper half of the hood in the flow momentum direction. Due to this pattern of flow direction, vortex generation in upper exhaust hood is reduced and increased flow diffusion results. The geometric arrangement can eliminate the outer casing of the exhaust hood over the axial length of the turbine inner casing, allowing the turbine inner casing to be supported directly by a foundation for the steam turbine.

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 steam turbine includes a diffuser that has a bearing cone and an inner plate of a steam guide that define a passage through which steam flows. An outer plate is disposed with respect to the inner plate such that an opening is located between the inner and outer plates. At least one hole is located in the inner plate. A water tube is disposed in the opening, the water tube having water flowing therethrough which condenses at least a portion of a flow of steam flowing in the passage thereby creating at least a partial vacuum within the opening. The vacuum creates a suction effect through the at least one hole in the inner plate that can cause at least a portion of the flow of steam in the passage to attach itself to an inner surface of the inner plate.

Abstract: An exhaust hood for an axial steam turbine that includes a radial channel, downstream from the normal flow pattern. The radial channel guides the exhaust steam flow in upper half of the hood in the flow momentum direction. Due to this pattern of flow direction, vortex generation in upper exhaust hood is reduced and increased flow diffusion results. The geometric arrangement can eliminate the outer casing of the exhaust hood over the axial length of the turbine inner casing, allowing the turbine inner casing to be supported directly by a foundation for the steam turbine.