The coal-fired power industry is a significant source of environmental pollution. Nowadays, thermal power plants mostly use coal as fuel. As a result, combustion produces nitrogen oxides, leading to stricter requirements for the energy industry. This research is devoted to heat and mass transfer processes during pulverized coal combustion with the use of OFA technology to reduce harmful emissions. The authors developed the geometry and partitioning of the computational domain into control volumes and generated a mathematical model of pulverized coal flame. Based on the results of computational experiments, a graphical interpretation of the obtained results and their verification was carried out, allowing the authors to confirm that the introduction of OFA technology can significantly reduce the amount of nitrogen oxides.