Method and Apparatus for Controlling Gas Turbine Combustor

Abstract

An apparatus for controlling a gas turbine combustor having a diffusion combustion burner and a premix combustion burner comprising: a rotating speed detector for detecting a rotating speed of gas turbine, a recorder for recording the detected value of the rotating speed of gas turbine detected by the rotating speed detector, an arithmetic unit for calculating a change with time of the rotating speed of gas turbine in accordance with details of the detected value of the rotating speed of gas turbine recorded in the recorder, and a fuel control unit for judging a starting situation of reduction in the rotating speed of gas turbine on the basis of the change with time of the rotating speed of gas turbine calculated by the arithmetic unit and controlling respectively a fuel flow rate for the diffusion combustion burner to be fed to the diffusion combustion burner installed in the gas turbine combustor and a fuel flow rate for the premix combustion to be fed to the premix combustion burner.

Description

CLAIM OF PRIORITY[0001]The present application claims priority from Japanese patent application JP 2010-198518 filed on Sep. 6, 2010, the content of which is hereby incorporated by reference into this application.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a method and an apparatus for controlling a gas turbine combustor.[0004]2. Description of Related Art[0005]In the gas turbine combustor, there are a diffusion combustor and a premix combustor available. The diffusion combustor is a system for separately feeding and burning fuel and air in a combustion chamber, and a flame is formed in a state close to the stoichiometric ratio of fuel to air, and the local flame temperature rises, so that although the combustion stability is high, the nitrogen oxide (NOx) emission increases.[0006]On the other hand, the premix combustor is a system for premixing fuel and air and then feeding and burning them in the combustion chamber, and the mixi...

AI Technical Summary

Benefits of technology

[0013]The regulation and social demands on the environment become stronger day by day and also in the gas turbine combustor, a further reduction in the NOx emission is required. In the base load operation state from the partial load of the gas turbine, the combustion of the gas turbine combustor is switched to the mixed combustion of the diffusion combustion and premix combustion, thus the NOx emission rate can be reduced.

[0014]Further, in the gas turbine, to suppress the increase in the rotating speed due to the load dump, the fuel for the premix combustion is dumped at the time of load dump and so as to switch to the independent diffusion combustion, the fuel flow rate fed to the gas turbine combustor is controlled.

[0017]An object of the present invention is to provide a method and an apparatus for controlling a gas turbine combustor capable of ensuring combustion stability immediately after load dump of the gas turbine and reducing the NOx emission due to full speed no-load operation after the load dump.

[0024]According to the present invention, a method and an apparatus for controlling a gas turbine combustor capable of ensuring combustion stability immediately after load dump of the gas turbine and reducing the NOx emission due to full speed no-load operation after the load dump can be realized.

Problems solved by technology

When the full speed no-load operation state after the load dump is held for many hours, the independent diffusion combustion state of a high NOx emission is continued, so that an increase in the NOx emission due to the full speed no-load operation state after the load dump causes a problem.

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