In light of a 350 megawatt supercritical cogeneration tangential boiler, the
combustion and the nitrogen oxides release mechanism in the furnace were
numerically simulated. The combustion characteristics were analyzed, and
the influencing factors, such as the pulverized coal concentration, the
velocity of separated over-fire air and the boiler load, on nitrogen oxides
release in the furnace were also systematically studied. The results show
that the central airflow in the furnace rises spirally, and an inverted ?V?
type temperature distribution is formed. The generation of nitrogen oxides
can be effectively restrained by increasing the concentration of pulverized
coal properly. Compared with the conventional concentration, the
concentration of nitrogen oxides at the furnace exit can be reduced by
29.63% by taking high pulverized coal concentration. The concentration of
NOx at the furnace exit can be drastically reduced by increasing the
velocity of separated over-fire air. When decreasing boiler load, the
concentration of NOx at furnace exit declines at first and then increases.
Numerical simulation of NOx emission characteristics during combustion in 350 MW supercritical cogeneration tangentially boiler