Method for heating up a steam turbine or for keeping a steam turbine hot

Abstract

A method for heating up a steam turbine or for keeping a steam turbine hot, which steam turbine has at least one pressure stage working at an initial pressure or intermediate pressure, at least one final pressure stage which is fluidically connected downstream of the pressure stage and works at a final pressure which is lower than the initial pressure or intermediate pressure, and at least one condenser which is connected downstream of the final pressure stage, wherein steam generated outside the steam turbine is introduced into the pressure stage. After flowing through the pressure stage and bypassing the final pressure stage, the steam is supplied directly to the condenser.

Claims

1. A method for heating up a steam turbine or for keeping a steam turbine hot, which steam turbine comprises at least one pressure stage which operates at an initial or intermediate pressure level, at least one final pressure stage which operates at a final pressure level which is lower than the initial or intermediate pressure level and is fluidically connected downstream of the at least one pressure stage, and at least one condenser which is connected downstream of the at least one final pressure stage, the method comprising: introducing steam which is generated outside the steam turbine into the at least one pressure stage, feeding the steam directly to the at least one condenser after the steam flows through the at least one pressure stage, thereby bypassing the at least one final pressure stage, generating a vacuum on an inlet side of an extractor disposed in a discharge line between an outlet of the at least one pressure stage and an inlet of the extractor, and extracting the steam from the at least one pressure stage by means of the vacuum.

2. The method as claimed in claim 1, wherein the extractor comprises at least one fan.

3. The method as claimed in claim 1, further comprising: closing a throttle flap which is arranged in a crossflow line between the at least one pressure stage and the at least one final pressure stage during the introduction of the steam into the at least one pressure stage.

4. A system for heating up a steam turbine or for keeping a steam turbine hot, which steam turbine comprises at least one pressure stage which operates at an initial or intermediate pressure level, at least one final pressure stage which operates at a final pressure level which is lower than the initial or intermediate pressure level and is fluidically connected downstream of the at least one pressure stage, and at least one condenser which is connected downstream of the at least one final pressure stage, the system comprising: a steam generator configured to introduce steam into the at least one pressure stage; a discharge line configured to discharge the steam from the at least one pressure stage and to directly feed the steam which is discharged from the at least one pressure stage to the at least one condenser, thereby bypassing the at least one final pressure stage, and an extractor fluidically connected to the discharge line and configured to generate a vacuum in the discharge line on an inlet side of the extractor to extract the steam from the at least one pressure stage.

5. The system as claimed in claim 4, further comprising: at least one shut-off device which is formed by way of a throttle flap which is arranged in a crossflow line between the at least one pressure stage and the at least one final pressure stage, which shut-off device is closeable during the introduction of the steam into the at least one pressure stage.

6. A power plant or a combined gas/steam turbine power plant or a steam power plant, comprising: at least one steam turbine, comprising at least one system as claimed in claim 4.

7. A system for heating up a steam turbine or for keeping a steam turbine hot, which steam turbine comprises a high-pressure stage, an intermediate-pressure stage, and a low-pressure stage, and a condenser connected downstream of the low-pressure stage, the system comprising: a steam generator configured to introduce steam into the intermediate-pressure stage; a discharge line configured receive the steam from the intermediate-pressure stage and to directly feed the steam to the condenser, thereby bypassing the low-pressure stage, and an extractor fluidically connected to the discharge line and configured to generate a vacuum in the discharge line on an inlet side of the extractor to extract the steam from the intermediate-pressure stage.

8. The system of claim 7, wherein the extractor comprises a fan.

9. The system of claim 7, further comprising: a crossflow line between the intermediate-pressure stage and the low-pressure stage, and a shut-off device arranged in the crossflow line between the intermediate-pressure stage and the low-pressure stage, which shut-off device is closeable during the introduction of the steam into the intermediate-pressure stage.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawing: the sole FIGURE shows a diagrammatic illustration of one exemplary embodiment for a system according to the invention.

DETAILED DESCRIPTION OF INVENTION

(2) The FIGURE shows a diagrammatic illustration of one exemplary embodiment for a system 1 according to the invention for heating up a three-stage steam turbine 2 or for keeping a three-stage steam turbine 2 hot, which steam turbine 2 has a high pressure stage 3 which operates at an initial pressure level or high pressure level, a pressure stage 4 or middle pressure stage which operates at an intermediate pressure level or middle pressure level, a final pressure stage 5 which operates at a final pressure level or low pressure level and is fluidically connected downstream of the pressure stage 4, and a condenser 6 which is connected downstream of the final pressure stage 5. The high pressure stage 3, the pressure stage 4 and the final pressure stage 5 are coupled mechanically via a common rotor shaft 7.

(3) The system 1 comprises a device 8 for generating steam and for introducing the steam into the pressure stage 4 or middle pressure stage. To this end, the device 8 has a steam generation unit 9 which generates the steam as a main product or auxiliary product. Furthermore, the device 8 comprises a feed line 10 which opens into the pressure stage 4 and in which an electrically actuable valve 11 is arranged which is opened for heating up the steam turbine 2 or for keeping the steam turbine 2 hot.

(4) Furthermore, the system 1 comprises an apparatus 12 for discharging the steam, after flowing through the pressure stage 4 or middle pressure stage, from the pressure stage 4 and for feeding the steam which is discharged from the pressure stage 4 directly to the condenser 6 bypassing the final pressure stage 5 or low pressure stage. In order to discharge the steam from the pressure stage 4, the apparatus 12 comprises a means 13 in the form of a fan for extracting the steam from the pressure stage 4, which means 13 is arranged in an extraction line 14 of the apparatus 12. The extraction line 14 directly follows the pressure stage 4. As an alternative to the extraction line 14, an extraction line 15 which is shown using dash-dotted lines can be present, which extraction line 15 connects a crossflow line 16 between the pressure stage 4 and the final pressure stage 5 to the condenser 6 in a fluid-conducting manner. A shut-off device 17 which is formed by way of a throttle valve and is closed during the introduction of the steam into the pressure stage 4 is arranged on the crossflow line 16.

(5) Although the invention has been illustrated and described relatively closely in detail by way of the preferred exemplary embodiment, the invention is not restricted by the disclosed example and other variations can be derived herefrom by a person skilled in the art, without departing from the scope of protection of the invention.