Diffuser arrangement

Abstract

A diffuser arrangement through which a fluid may flow is provided. The diffuser includes an outer diffuser comprising an inner surface, and a flow-guiding device, which is configured such that at least part of the boundary layer flow forming on the inner surface of the outer diffuser can be accelerated in the main flow direction, so that a flow separation is prevented on the inner surface of the outer diffuser. Also provided are an exhaust steam plenum of a steam turbine and an exhaust gas plenum of a gas turbine, both including a diffuser arrangement.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is the US National Stage of International Application No. PCT / EP2008 / 052222, filed Feb. 25, 2008 and claims the benefit thereof. The International Application claims the benefits of European Patent Office application No. 07005175.0 EP filed Mar. 13, 2007, both of the applications are incorporated by reference herein in their entirety.FIELD OF INVENTION[0002]The invention refers to a diffuser arrangement and especially to an exhaust steam plenum of a steam turbine or an exhaust gas plenum of a gas turbine with the diffuser arrangement.BACKGROUND OF INVENTION[0003]A diffuser is a passage which is exposable to throughflow by fluid and which in the case of separation-free throughflow decelerates the fluid by means of cross-sectional widening and, in accordance with Bernoulli's theorem, reduces the kinetic pressure of the fluid to the benefit of the static pressure.[0004]The quality of the diffuser is described by means of the...

AI Technical Summary

Benefits of technology

[0023]The diffuser arrangement according to the invention is exposable to throughflow by fluid and has an outer diffuser which has an inner surface, and a flow-accelerating device which is installed in such a way that at least some of the boundary layer flow which develops on the inner surface of the outer diffuser can be accelerated in the main flow direction so that a flow separation on the inner surface of the outer diffuser is prevented.

[0043]In this way, the effect is advantageously achieved of the flow-guiding device being able to be individually adjusted by pivoting with regard to the respective flow conditions inside the outer diffuser in such a way that the flow-guiding device is aerodynamically effective.

Problems solved by technology

If the fluid flows through the outer diffuser, then it is decelerated in the main flow direction, as a result of which the boundary layer flow which develops on the inner surface of the outer diffuser is principally prone to separation.

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