Abstract: Oxygen-enriched combustion of coal is a potential CO₂ emission reduction technology.In order to make the modified power plant boiler compatible in air atmosphere and O₂/CO₂ atmosphere and save the cost of transformation,the numerical simulation of 300 MW tangentially fired pulverized boiler was carried out.By changingφ（O₂）/φ（CO₂）（volume fraction ratio of O₂ and CO₂）entering the furnace,the combustion and heat transfer characteristics similar to those in air atmosphere are expected to be obtained.The variation of temperature,O₂ volume fraction,particle burnout rate with furnace height and thermal load characteristics under four working conditions were studied.The simulation results show that the trend of O₂ volume fraction in cross section of furnace varies with the height of furnace in air atmosphere and oxygen-rich atmosphere.Whenφ（O₂）/φ（CO₂） is 25/75,the flue gas volume,flue gas temperature and the residence time of particles in the furnace can be similar to that in air atmosphere.From the point of view of heat flux,radiation heat transfer is the main heat transfer method in furnace combustion.Increasing oxygen concentration is beneficial to heat transfer and improve the safety and stability of combustion.In general,increasing the proportion of O₂ in the furnace can reduce the heat loss of exhaust and make the pulverized coal burn completely.