微粉炭燃焼におけるNO_x統括反応モデルの改良

抄録

The global reaction rate expressions for N intermediates (HCN and NH₃) proposed by De Soete were frequently used in NO_x simulation of pulverized coal (PC) combustion. However, the oxidation rate of HCN calculated by De Soete's expressions is largely underestimated in the typical condition of PC combustion. In this study, the oxidation rate of HCN is recommended to be increased. The modified NO_x model was used to simulate the NO_x concentration distribution for two coals in a down-fired autothermal test furnace. A satisfactory agreement for the NO_x concentration distributions between simulation and measurement could be obtained using the increased HCN oxidation rate, if proper char surface area values (S) were chosen. It was found that the S leading to the best simulation results for two coals were both proportional with those measured by Hg porosimetry.