Combustion control device for gas turbine

A combustion control device for a gas turbine which is fitted to a gas turbine provided with a gas turbine body, a combustor having multiple types of fuel nozzles, a compressor having an inlet guide vane, and multiple fuel flow rate control valves for respectively controlling fuel supplies to the multiple types of the fuel nozzles, and which is configured to control the fuel supplies to the multiple types of the fuel nozzles by controlling apertures of the fuel flow rate control valves, the combustion control device comprising:

• first gas turbine output computing means for computing a first gas turbine output corresponding to a first combustion gas temperature at an inlet of the gas turbine based on an intake-air temperature of the compressor and an aperture of the inlet guide vane;
• second gas turbine output computing means for computing a second gas turbine output corresponding to a second combustion gas temperature at the inlet of the gas turbine higher than the first combustion gas temperature at the inlet of the gas turbine based on the intake-air temperature of the compressor and the aperture of the inlet guide vane;
• and
• combustion load command computing means for computing a combustion load command value to render the combustion gas temperature at the inlet of the gas turbine dimensionless by direct interpolation based on the first gas turbine output computed by the first gas turbine output computing means, the second gas turbine output computed by the second gas turbine output computing means, and an output of the gas turbine,
• wherein ratios of fuels to be supplied respectively to the multiple types of the fuel nozzles are determined based on the combustion load command value computed by the combustion load command computing means, and the fuel supplies to the multiple types of the fuel nozzles are controlled by controlling apertures of the fuel flow rate control valves based on the ratio of the fuels.