Analysis of Pressure Effect on NOx Emission Predicted by EDC Models Adopted in a Model Gas Turbine Combustor

Pressure effects on NOx emission in a gas turbine combustor are numerically investigated using the EDC model in the study. To validate the combustion analysis involving air-fuel mixing and chemical reactions under turbulent conditions, we adopt two models of the Standard EDC and Partially Stirred Reactor EDC models and compare one model with the other. As pressure increases, NOx emission decreases slightly to 5.87 ppm with the Standard EDC model adopted, while it significantly increases to 37 ppm with the Partially Stirred Reactor EDC model adopted. While the temperature difference between the two EDC models is negligibly small, NOx emissions predicted by the Partially Stirred Reactor EDC model increase geometrically. This confirms that temperature is not a primary parameter in NOx emissions when comparing EDC models. The correlation between factors expressed by functions of chemical and mixing time scales can be considered to find effects of pressure on NOx emissions.