Control of primary measures for reducing the formation of thermal nitrogen oxides in gas turbines

A method of controlling primary measures for reducing the formation of thermal nitrogen oxides in the combustion process in a gas turbine, the method comprising:

• determining a relative air mass flow rate through the gas turbine as related to a reference air mass flow rate at a reference ambient air temperature, ambient air pressure, ambient air humidity, inlet guide van position, and compressor inlet temperature, as a function of at least one of actual ambient air temperature, ambient air pressure, ambient air humidity, inlet guide vane position, and compressor inlet temperature;
• determining relative shaft power output as related to a reference shaft power output at an output shaft of said gas turbine;
• determining a relative thermal power as a function of said relative shaft power output;
• calculating a combustion process control variable as a function of said relative air mass flow rate and said relative thermal power;
• and
• controlling a primary measure for reducing the formation of thermal nitrogen oxide in the combustion process of said gas turbine using the combustion process control variable, wherein the combustion process control variable (SPRR), is calculated from the formula:
• SPRR=(Pact/mair)/(1−ΠA)
• in which formula
• Pact=the relative shaft power output of the gas turbine,
• mair=the relative air mass flow rate through the gas turbine engine,
• Π=the ratio of the combustion-chamber pressure to the ambient pressure, and
• A=an exponent determined partly empirically by measuring nitrogen oxide emissions of the gas turbine at various shaft power outputs of the gas turbine.

A method of controlling the formation of thermal nitrogen oxides in the combustion process in a gas turbine, the method comprising:

• determining a relative air mass flow rate through the gas turbine as related to a reference air mass flow rate at a reference ambient air temperature, ambient air pressure, ambient air humidity, and compressor inlet temperature, as a function of at least one of actual ambient air temperature, ambient air pressure, ambient air humidity, inlet guide vane position, and compressor inlet temperature;
• determining relative shaft power output as related to a reference shaft power output at an output shaft of said gas turbine;
• determining a heat release rate as a function of said relative shaft power output;
• calculating a combustion process control variable as a function of said relative air mass flow rate and said heat release rate;
• selecting at least one control parameter of the combustion process, which control parameter directly effects the formation of thermal nitrogen oxides in the combustion process, from the group consisting of:
• the ratio of the rates of addition of fuel to at least two burners or burner groups;
• the rate of addition of inert material to the combustion process;
• the rate of addition of air to the combustion process;
• and
• combinations thereof;
• and
• controlling the at least one control parameter of said gas turbine using the combustion process control variable to reduce the formation of thermal nitrogen oxide in the combustion process.