Effect of Local Oxygen-enrichment Ways of Oxygen-coal Double Lance on Coal Combustion

摘要

The extent of coal combustion within the tuyere and raceway region is one key factor affecting the maximum pulverized coal injection (PCI) rate. Oxygen enrichment, especially local oxygen enrichment, is the most effective way to increase the PCI rate. In this study, a three-dimensional numerical model was developed to simulate the lance-blowpipe-tuyere-raceway of a blast furnace. In the study, the characteristics of oxygen-coal combustion are investigated under the single oxygen-coal and oxygen-coal double lances. Under local oxygen enrichment ways, the oxygen content around the coal particles increases significantly, benefiting coal combustion. However, the cooling effect of room-temperature oxygen delays coal combustion. Therefore, the way by which the oxygen flows should not be neglected. The results indicate that the increase in the burnout is quite different under different lance patterns. The burnout had the maximum increase of 2.17% under the coaxial oxygen-coal lance. The burnout had the highest increase of 12.84% under the oxygen-coal double lance.