Combustion simulation and emission control in natural gas fuelled combustor of gas turbine

This paper presents a systematic method for the estimation of theoretical value of temperature produced in the gas turbine combustor through MATLAB simulation. The fuel used is natural gas. The assumption of adiabatic combustion has been used for the simplicity of the analysis. For getting accurate results, the combustion process has been analyzed considering the variation of specific heat of gases with temperature. The theoretically calculated temperature has been compared with the actual temperature produced in an actual gas turbine combustor to validate the thermodynamic model. One of the most hazardous pollutants from a gas turbine is nitrogen oxides (NOx) whose formation takes place due to dissociation of nitrogen at high temperature and its subsequent reaction with oxygen. To avoid NOx formation, the flame temperature has been lowered to 1355 K by increasing the amount of excess combustion air. Therefore, the effect of excess air on the combustion temperature and power output has been investigated in this study. The theoretical power output has also been compared with the actual output. The method described in this paper may prove to be useful not only to the designers of gas turbine but also to the researchers analyzing other types of combustion systems.