At present

there is an urgent need to effectively control and optimize the combustion process of gas turbine units to control NO_x emissions. Taking a Germany Siemens SGT5-4000 F(4) heavy duty gas turbine as the research object

the influences of the parameters of air system

fuel system

combustion system and exhaust system on NO_x emissions at different loads during a simple cycle combustion process are studied. The results show that

the pressure ratio of compressor

IGV valve position and differential pressure of combustion chamber vary linearly with the load of the gas turbine. The pilot gas flow and the turbine exhaust gas temperature are the important parameters that affect NO_x production. When the gas turbine load is lower than 110 MW

the NO_x emission concentration increases with the gas turbine load. When the gas turbine load is higher than 110 MW

with the increasing of the gas turbine load

the NO_x emission concentration rapidly decreases to the lowest value and then gradually increases to the constant.