Study On The Influence Of Structural Parameters Of Shell Gasifier Based On Stability And Gasification

Shell coal gasification technology is the representative of dry feed entrained-flow gasification technologies. Since the technology was introduced to China, it exists problems include the poor stability of Shell gasifier and the gasification performance can not reach the standard. This paper study the problems form the structure of gasifier.Establish the three dimensional CFD model of Shell gasifier based on computational fluid dynamics. Study the effect of gasifier structure parameters of burner angel、burner height and height to diameter ratio of gasifier to the stability of gasifier, the results show that the change of structure parameters have different effect on the stability of gasifier. The change of burner angel has big effect on the stability of gasifier and the stability of gasifier will be the best when the burner angel is0°; The stability of gasifier improve when the burner height increase in the range10%-30%while the stability of gasifier decline when the burner height beside the range; The stability of gasifier improve when the height to diameter ratio of gasifier increase in the range2-4, but the effect of the height to diameter ratio of gasifier on the stability of gasifier decline when the height to diameter ratio of gasifier increase.Study the effect of gasifier structure parameters on gasification performance with the three dimensional CFD model of Shell gasifier, and then establish RSM model to study the effect of structure parameters on gasification performance under the interaction effect of process parameters. The results show that the change of structure parameters have effect on gasification performance and the gasification performance will be the best when the burner angel is0°, burner height is30%, the height to diameter ratio of gasifier is3.5; The effect of structure parameters on gasification performance will change when the process parameters change. When the oxygen-coal ratio is high or the steam-coal ratio is low, the change of gasification performance is relatively small when the height to diameter ratio of gasifier change and the best gasification performance was observed when the burner height at low level. When the oxygen-coal ratio is low or the steam-coal ratio is high, the change of gasification performance is relatively big when the height to diameter ratio of gasifier change and the best gasification performance was observed when the burner height at high level. The change of structure parameters have effect on the best value of process parameters. When the burner height is high or the height to diameter ratio of gasifier is big, the best value of oxygen-coal ratio is relatively low and the best value of steam-coal ratio is relatively high. When the burner height is low or the height to diameter ratio of gasifier is small, the best value of oxygen-coal ratio is relatively high and the best value of steam-coal ratio is relatively low.