Abstract: In this paper, the research and analysis on pulverizing system parameter determination and coal mill type selection is conducted for the large oxy-fuel power plant compatible with air combustion. By taking the approach of combining design calculation and theoretical analysis, the effect of high CO2 atmosphere on the parameters of the mill and coal pulverizing system is studied so as to obtain the parameters of typical coal such as the mill outlet temperature, coal powder fineness, ventilation volume, pulverized coal pipeline flow rate and so on under 200-MW compatible air and oxy combustion conditions. Considering the pulverized coal jam, corrosion and explosion, etc., the oxygen partial pressure of primary air should be maintained at 18% and the water contents at flue gas condenser outlet should be limited below 5%, while the optimal pulverizer outlet temperature of oxygen enriched dry cycle should stay between 77 ℃ and 80 ℃, and that of wet cycle should be kept between 95 ℃ and 100 ℃. Through parameter comparisons, preventive measures against wearing, leakage and corrosion are put forward. Consequently, the key parameters of coal mill and pulverizing system are tuned well to match each other in compatible air-oxygen combustion operation.

Key words: oxy-fuel combustion, compatibility, mill, parameter, corrosion prevention