Gas turbine system and method for modifying gas turbine system

A method for modifying a gas turbine system, including:

• preparing a program for controlling the gas turbine system, the gas turbine system comprising:
• a gas turbine that includes a combustor;
• a first line that is fluidly connected to the combustor and that supplies a first fuel to the combustor;
• a second line that is fluidly connected to the combustor and that supplies a second fuel of which flame temperature is lower than that of the first fuel to the combustor;
• a first adjuster that is provided in the first line and that adjusts a first flow rate of the first fuel flowing into the combustor;
• a second adjuster that is provided in the second line and that adjusts a second flow rate of the second fuel flowing into the combustor;
• and
• a controller that is communicatively connected to the first adjuster and the second adjuster,
• the program causing a computer to execute:
• calculating a flow rate ratio indicating a ratio between the first flow rate and the second flow rate;
• and
• controlling the first adjuster and the second adjuster based on the flow rate ratio, and
• installing the program on the controller.