Effects of Swirling Strength of the Premixed Gas Flow on Pollutant Emission in a Heavy-Duty Gas Turbine

College of Energy and Mechanical Engineering, Shanghai University of Electric Power, Shanghai 200090, China

^* Corresponding author: fuzaiguo@shiep.edu.cn

Abstract

The combustion process and pollutant emission of an annular combustion chamber for a heavy-duty gas turbine were investigated by numerical method. The realizable k-ε model and finite rate/eddy dissipation model were adopted for calculations of turbulence and combustion. The effects of different swirling numbers of the double-swirler inlet on the temperature distribution and the thermal NO_x formation in the combustion chamber were analyzed. The results show that the change of the swirling number of the outer swirling flow has a greater influence on the generation of the thermal NO_x when compared with that of the inner swirling flow. The maximum average temperature of the central cross section of the combustor does not exceed 1760K. The average mass fraction of the generated thermal NO_x at the exit decreases with the increasing outer swirling number. When the outer swirling number is less than 0.8, the generation of the thermal NO_x is severe at the side wall of the combustion chamber.