Numerical simulation of the formation of nitric oxides in the combustion of coal-dust fuel

A mathematical model and a method of calculating two-phase flows and heat a nd mass transfer in industrial combustion chambers operating on coal-dust f uels are given. The numerical model of coal-dust combustion in a high-tempe rature turbulent how is based on three-dimensional steady-state equations o f mechanics of heterogeneous media and describes the processes of yield and combustion of fuel volatiles, afterburning of the coke residue, radiative heat transfer in the combustion chamber, and the effect of the disperse pha se on the turbulent structure of the carrier medium. To predict the concent ration of nitric oxides inside a combustion chamber, an effective numerical model of NO formation during jet burning of coal dust, which is based on t he Mitchell-Tarbell kinetic scheme, is proposed. The results obtained in th e use of the proposed complex numerical model are in good agreement with ex perimental data for industrial combustion chambers. The degree of detail en sured by the calculations allows one to make effective decisions to organiz e coal-dust burning with a decreased yield of hazardous nitric oxides.