As a clean energy technology

oxygen-enriched combustion can be used in boiler renovation to reduce pollutant emissions and recover CO_2. To study the difference of furnace combustion between in air atmosphere and in oxygen-enriched environment

the heat transfer characteristics of combustion in furnace of a subcritical 300 MW tangentially fired pulverized coal furnace are studied by numerical simulation. By adjusting such parameters as the volume fraction of O_2

the volume fraction of flue gas entering the furnace

and the volume of primary air and secondary air

the flame temperature in oxygen-enriched atmosphere that is similar to that in air atmosphere is obtained. The change rules of flow field

temperature field

volume fraction of O_2

CO_2 and CO in the furnace under seven conditions

as well as the mean volume fraction of O_2

CO_2 and CO in cross-section of the furnace with the furnace height were investigated. The simulation results reveal that

the flow fields in the furnace are similar in both air and oxygen-enriched combustion atmospheres. However

with the same volume fraction of oxygen

replacing N2 with CO_2 will cause a decrease in the furnace temperature and make the flame center move down. Increasing the oxygen volume fraction can improve the heat transfer characteristics and make the pulverized coal combustion more stable.