Methods, systems and/or apparatus relating to steam turbine exhaust diffusers

Abstract

An axial flow steam turbine flow path that includes a rotor and a casing defining the axial steam flow path; and a toroidal diffuser for diffusing the exhaust steam and turning the exhaust steam from a generally axial flow direction to a generally transverse or vertical and tangential direction; wherein the toroidal diffuser comprises a diffuser that, at least in part, incorporates the shape of a toroid or a section of a toroid; and wherein a toroid comprises the shape generated by revolving a circular or oval shape in three dimensional space about an axis coplanar with the circular or oval shape, which does not touch the circular or oval shape.

Description

BACKGROUND OF THE INVENTION[0001]This present application relates generally to methods, systems, and / or apparatus for improving the efficiency and / or operation of turbine engines. More specifically, but not by way of limitation, the present application relates to methods, systems, and / or apparatus pertaining to improved steam turbine diffusers and related components.[0002]In conventional steam turbine design, the inner case of the steam turbine, which, for example, may be a double flow down exhaust unit, has an encompassing exhaust hood split vertically and extending along opposite sides and ends of the turbine. This large box-like structure houses the entire low pressure section of the turbine. The exhaust steam from the turbine flows downstream in a general axial direction. Then, the steam exhaust is redirected from an axial flow direction to a flow direction 90° relative to the axial flow direction. This 90° flow direction may be in any plane, downwardly, upwardly or transversely...

AI Technical Summary

Benefits of technology

"The patent describes a steam turbine with a rotor and casing that has a toroidal diffuser to change the direction of exhaust steam. The diffuser is designed to look like a torus, which is a shape created by rotating a circular or oval shape in three dimensions around a central axis. The technical effect of this design is that it helps improve the performance and efficiency of the steam turbine by better controlling the flow of exhaust steam."

Problems solved by technology

The steam flow path was thus somewhat tortuous, which resulted in losses and adverse pressure drop.

It will also be appreciated that access to various parts of the turbine, for example, the bearing for maintenance purposes was difficult in that it could necessitate the removal of the upper half of the exhaust hood.

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