Alstom Technology Limited

Asea Brown Boveri Ag

Ralf Greim

Said Havakechian

Ivan William McBean

Axel Pfau

Simon-Pierre Monette

Mourad Lakehel

Lale Demiraydin

Harald Romer

Peter Szincsak

Ivan Mcbean

A blade of a turbomachine, especially of a steam turbine, is characterized in that the chord length (s) in the middle region of the blade airfoil is shorter than the chord lengths (s, S) in the tip-side region or root-side region of the blade airfoil. As a result of this, a distribution of a Zweifel parameter over the longitudinal extent of the blade airfoil is achieved which minimizes the losses of a blade cascade of the blades.

Turbomachine blade with variable chord length

A steam turbine is provided having a rotor which rotates around a machine axis, and a stator which concentrically encompasses the rotor with clearance, between which an annular passage is formed which is exposed to throughflow by steam in the axial direction and in which a multiplicity of rotor blades, which are fastened on the rotor, and fixed stator blades are arranged in a plurality of stages, wherein the stator blades of the last stage have a sweep with a sweep angle which changes in sign over the relative blade height.

Steam turbine

A diffuser and exhaust system is provided for a turbine having an axial-radial diffuser and an exhaust hood including diffuser inner and outer flow guides that extend from an inlet to an outlet. The exhaust hood includes two throats or flow passages between the diffuser outlet and an exhaust hood side wall. The outer flow guide includes a recess, at one of the said two flow passages. The flow passage is positioned in relation to a point in the exhaust hood in the direction of the tangential flow velocity vector, where the point in the exhaust hood is farthest away from the exhaust hood outlet. The recess prevents a re-acceleration of the flow within the exhaust hood and affects an increase in the performance of the diffuser and exhaust hood system.

Diffuser and exhaust system for turbine

The blades of a turbomachine comprise airfoils, which are bent such that the lean angle (&#x3c6;), defined as the angle which the stacking line of the airfoil includes with the radial direction, and measured in the direction of rotation (&#x3c9;), is variable along the width of the flow channel and decreases from the hub towards the housing.

Turbomachine blade

A turbine () of a turbine installation, especially a steam turbine of a steam turbine installation, includes at least one radial or diagonal turbine stage () with radial or diagonal inflow and axial outflow, and also at least one axial turbine stage (-) with axial inflow and axial outflow. The at least one radial or diagonal turbine stage () forms the first stage of the turbine () and the at least one axial turbine stage (-) is arranged downstream of the radial or diagonal turbine stage () as an additional stage of the turbine. The at least one radial or diagonal turbine stage () has a higher temperature resistance than the at least one axial turbine stage (-). The turbine () makes it possible to significantly increase the process temperature of the steam turbine installation, wherein measures for increasing the temperature resistance need only to be adopted for components of the radial or diagonal turbine stage ().

Turbine

A turbomachine has, on its inner casing () and on its shaft, recesses into which shrouds of rotor blades and/or of guide vanes () protrude. The recesses are configured with wave-shaped contouring arrangements (), which extend over their periphery. The contouring () extends over axially extending regions of the recess and consists of periodic elevations and depressions () in the radial direction. They can also be effected on the radially extending regions of the recess and on the shrouds. The undulation-shaped contouring arrangements are used to counteract existing pressure fields and to reduce performance losses due to mixing processes between the leakage flow and the main flow.

Turbomachine

To reduce the number of stages of a turbine and, associated therewith, the overall length and the costs, blading having high stage-specific enthalpy transfer is to be used. In this case, the disadvantages of conventional highly loaded blading, such as increased secondary flow losses due to blades of large chord length and comparatively small height and the design of the turbine in the complicated chamber type of construction, are to be avoided. Resulting from these requirements is a highly loaded slim blade type of construction having considerable deflection. A turbine having blading according to the invention is characterized by a loading parameter RBL, which in the HRBL blading according to the invention, in contrast to conventional types of construction, is greater than 1.

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Birmenstorf, Switzerland

Ralf Greim