Combined cycle plant, control device thereof, and steam turbine startup method

Patent metadata

Field	Value
Publication number	US-11506089-B2
Application number	US-201916731363-A
Country	US
Kind code	B2
Filing date	Dec 31, 2019
Priority date	Jul 12, 2016
Publication date	Nov 22, 2022
Grant date	Nov 22, 2022

Abstract

A combined cycle plant includes: a gas turbine having a compressor, a combustor, and a turbine; a supplementary firing burner configured to raise a temperature of an exhaust gas of the gas turbine; a heat recovery steam generator configured to generate a steam using an exhaust heat of the exhaust gas; a steam turbine configured to be driven by the steam generated by the heat recovery steam generator; and a control device configured to change both an output of the combustor and an output of the supplementary firing burner when an output of the combined cycle plant is to be changed.

First claim

The invention claimed is:

1. A method of starting up a combined cycle plant, the combined cycle plant comprising:
a gas turbine having a compressor, a combustor, and a turbine;
a supplementary firing burner configured to raise a temperature of an exhaust gas of the gas turbine;
a heat recovery steam generator configured to generate a steam using an exhaust heat of the exhaust gas of the gas turbine; and
a steam turbine configured to be driven by the steam generated by the heat recovery steam generator,
the method comprising:
starting up the gas turbine and the steam turbine;
increasing an output of the combustor while the supplementary firing burner is not started up until after completion of a warming up of the steam turbine;
starting up the supplementary firing burner when the warming up of the steam turbine is completed;
increasing the output of the combustor and an output of the supplementary firing burner after starting up the supplementary firing burner; and
after a target output of the combined cycle plant is reached by increasing the output of the combustor and the output of the supplementary firing burner,
increasing the output of the combustor upon an increase in the target output of the combined cycle plant and upon the output of the combustor not reaching a maximum;
increasing the output of the supplementary firing burner upon the increase in the target output of the combined cycle plant and upon the output of the combustor reaching the maximum; and
making the output of the combustor constant and decreasing the output of the supplementary firing burner upon a decrease in the target output of the combined cycle plant after the target output of the combined cycle plant is reached by increasing the output of the combustor and the output of the supplementary firing burner.

Assignees

• Mitsubishi Hitachi Power Sys Ltd
• Mitsubishi Heavy Ind Ltd

Inventors

• Matsushiro Goichi
• Hatano Ken

Classifications

• F01K23/103 Primary

  with afterburner in exhaust boiler · CPC title

• F01K23/10

  with exhaust fluid of one cycle heating the fluid in another cycle (F01K17/025 takes precedence) · CPC title

• F01K17/025

  in combination with at least one gas turbine, e.g. a combustion gas turbine · CPC title

• F01D19/00

  Starting of machines or engines; Regulating, controlling, or safety means in connection therewith (warming-up before starting F01D25/10; turning or inching gear F01D25/34) · CPC title

• F01K23/105

  Regulating means specially adapted therefor · CPC title