NUMERICAL-ANALYSIS OF DIFFUSION COMBUSTION OF COAL-GASIFIED FUEL (EFFECT OF PRESSURE ON NOX FORMATION)

Numerical computations are made of laminar jet diffusion flames taking into account detailed chemical kinetics and multicomponent diffusion and focusing on the effect of pressure and the amounts of hydrocarbon contained in the fuel on the NOx formation processes and characteristi cs. In order to clearly distinguish between thermal NOx and fuel NOx o riginating from Nz in the air and fuel N, respectively, and to elucida te the effects of interaction between thermal NOx and fuel NOx togethe r with N-containing species, N-containing species originating from Nz in air and fuel N and their reactions are distinguished in the computa tions. It was shown that (1) higher pressure results in a decrease in the amount of fuel NO formed and a increase in the amount of thermal N O formed, (2) the tendency of the decrease of the conversion rate of a mmonia to fuel NO for high-pressure flames becomes more apparent when the fuel contains greater amounts of methane, (3) the effect of the de struction of thermal NO by N-containing species becomes more apparent for high-pressure flames as thermal NO concentration becomes high.