NOx FORMATION IN H2-CH4 BLENDED FLAME UNDER MILD CONDITIONS

In this article, NO production mechanisms for CH4-H-2 combustion under MILD (moderate or intense low-oxygen dilution) conditions are studied using CDF and also zero-dimensional well stirred reactor (WSR) analysis. A H-2/CH4 jet into a heated and diluted coflow is modeled in CFD analysis. The RANS equations with modified (k - epsilon) equations are solved in an axisymmetric 2D computational domain. The GRI2.11 full mechanism is considered to represent the chemical reactions. The effects of oxidizer oxygen concentration, fuel hydrogen content, and fuel jet Reynolds number are studied on NO formation reactions. Results show that the measurements are predicted with an acceptable accuracy. The NNH and N2O routes are the most important pathways in NO formation under MILD conditions. An increase in oxidizer O(2)concentration or decrease in fuel hydrogen content addressesthe decrease in importance of the mentioned NO formation routes.