Method for regulating a brief increase in power of a steam turbine

Patent metadata

Field	Value
Publication number	US-9080467-B2
Application number	US-201214001281-A
Country	US
Kind code	B2
Filing date	Feb 10, 2012
Priority date	Feb 25, 2011
Publication date	Jul 14, 2015
Grant date	Jul 14, 2015

Abstract

A method is provided for regulating a brief increase in power of a steam turbine that has an upstream fossil-fired once-through steam generator having a plurality of economizer, evaporator and superheater heating surfaces which form a flow path and through which a flow medium flows. The flow of the flow medium through the fossil-fired once-through steam generator is increased in order to achieve the brief increase in power of the steam turbine. The method involves using desired enthalpy value at the outlet of an evaporator heating surface as a control variable for determining a desired value for the flow of the flow medium through the fossil-fired once-through steam generator. The desired enthalpy value is reduced in order to achieve the brief increase in power of the steam turbine.

First claim

The invention claimed is:

1. A method for regulating a brief increase in power of a steam turbine that has an upstream fossil-fired once-through steam generator comprising a plurality of economizer, evaporator and superheater heating surfaces which form a flow path and through which a flow medium flows, the method comprising:
increasing the flow of the flow medium through the fossil-fired once-through steam generator in order to achieve the brief increase in power of the steam turbine,
using a desired enthalpy value at the outlet of an evaporator heating surface as a control variable for determining a desired value for the flow of the flow medium through the fossil-fired once-through steam generator, and
reducing the desired enthalpy value in order to achieve the brief increase in power of the steam turbine.

2. The method as claimed in claim 1 , wherein the desired enthalpy value is reduced to a predetermined minimum enthalpy value.

3. The method as claimed in claim 2 , wherein the minimum enthalpy value is dimensioned in such a way that complete evaporation of the flow medium in the evaporator heating surfaces is achieved under all load conditions of the fossil-fired once-through steam generator.

4. The method as claimed in claim 1 , wherein the magnitude and/or duration of the reduction in the desired enthalpy value is determined with reference to the required increase in power.

5. The method as claimed in claim 1 , wherein in order to achieve the brief increase in power of the steam turbine, flow medium taken from the flow path is injected in the region of a superheater heating surface of the fossil-fired once-through steam generator.

6. The method as claimed in claim 1 , wherein the heat supply to the fossil-fired once-through steam generator is increased.

Assignees

• Brückner Jan
• Effert Martin
• Thomas Frank
• Siemens Ag

Inventors

• Brückner Jan
• Effert Martin
• Thomas Frank

Classifications

• F22G5/12

  by attemperating the superheated steam, e.g. by injected water sprays · CPC title

• F01K13/02 Primary

  Controlling, e.g. stopping or starting · CPC title

• F22G5/02

  Applications of combustion-control devices, e.g. tangential-firing burners, tilting burners · CPC title

• F22D11/003

  Emergency feed-water supply · CPC title

• F22B35/10

  of once-through type · CPC title