Steam turbine comprising a thrust balance piston

Abstract

A cooling mechanism for a steam turbine is provided, which has, in the area of the valve connection a cooling channel, into which cooling steam flows from the flow channel, the steam then being fed as cooling steam in the area of the thrust balance piston.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is the US National Stage of International Application No. PCT / EP2012 / 065065 filed Aug. 1, 2012, and claims the benefit thereof. The International Application claims the benefit of European Application No. EP 11176574.9 filed Aug. 4, 2011. All of the applications are incorporated by reference herein in their entirety.FIELD OF INVENTION[0002]The invention relates to a steam turbine having an outer housing and an inner housing, a rotor, comprising a plurality of rotor blades, which has a thrust compensating piston being arranged in a rotationally mounted manner within the inner housing, the inner housing having an inner housing end region which is formed around the thrust compensating piston, a seal which seals a third pressure space which is arranged between the inner housing region and the outer housing, the inner housing having a feed channel which connects the first pressure space to a thrust compensating piston pre-spac...

AI Technical Summary

Benefits of technology

The invention is about a steam turbine that can cool itself effectively even at very high temperatures. One interesting feature is the design of the seal, which is a piston ring, which makes the turbine easier and cheaper to make.

Problems solved by technology

The prior art concerning gas turbines therefore cannot be used for this reason to assess the subject matter of the present application.

However, a temperature increase, in particular, is not possible to an unlimited extent for material reasons.

The temperature resistance of the components is usually limited depending on the choice of material.

Without efficient cooling, substantially more expensive materials (for example, nickel-based alloys) would be necessary in the case of rising temperatures.

In the case of loading of customary steam turbines with higher steam parameters, this can lead to increased thermal loading which acts on the entire turbine and could be reduced only insufficiently by an above-described customary cooling arrangement of the housing.

There is the problem here that, if previously customary turbine materials are used, the increasing loading of the steam turbine body by increased steam parameters can lead to disadvantageous thermal loading of the steam turbine which reduces the service life.

As a consequence of this, it is scarcely possible any more to produce steam turbines of this type economically.

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