关键词: 数值模拟, 分级气流床气化炉, 二次给氧, 气化炉流场

Abstract: The staged oxygen entrained flow coal-slurry gasifier has advantages such as higher carbon conversion rate, stronger turbulent mixing inside gasifier and lower temperature near coal slurry nozzle. In this article, effects of the secondary oxygen mass flow rate on gasification performance were numerically investigated through CFD simulation. The characteristics of the gasification flames were analyzed as well as the flow field under different secondary oxygen mass flow rate in the staged gasifier. As the mass flow rate of the secondary oxidizer decreases, the secondary gasification flame curves up with the backflow near the wall. At the same time, dome wall temperature increases as well. When the mass flow rate of the secondary oxidizer is less than 8% of the total oxidizer mass flow rate, the effect of the secondary oxidizer is too weak to change the macro flow field.

Key words: numerical simulation, stagedentrained flow coal gasifier, secondary oxygen, flow field in gasifier