Effects of the secondary oxygen injection on the performance of a staged-entrained flow caol gasifier

摘要

In a staged entrained flow coal-slurry gasifier, the secondary oxygen was injected into the gasifier in order to protect the refractory in the dome region, to improve the mixing process as well as gasification performance.Based on a proposed 3-D numerical model,simulations were conducted for the staged gasifier at different mass flow rates of the secondary oxidizer. The characteristics of the gasification flames were analyzed as well as the influence of the secondary flow on the flow field of the staged gasifier.As the mass flow rate of the secondary oxidizer decreases, the secondary gasification flame curves up according to the backflow region and wall temperature increases.When the mass flow rate of the secondary oxidizer is less than 10% of the total oxidizer mass flow rate, there is an obvious change of the turbulent mixing in the staged gasifier.