气基竖炉炉顶煤气循环工艺的理论分析

针对竖炉生产中存在的煤气还原势化学能未能充分利用的问题,提出3种竖炉炉顶煤气循环新工艺(top gas recycling,TGR)。基于物料平衡和热平衡建立了竖炉的静态工艺模型,对其进行了数值求解模拟和分析。结果表明,对于提出的工艺TGR1、TGR2、TGR3,煤气需求量分别减少63.77%、57.13%、55.85%,显热需求也呈现出相同趋势;但对于循环竖炉工艺而言,循环煤气重整和升温需要额外耗能,从而系统总能耗分别上升了5.68%、7.27%、17.12%,其中,TGR1流程CO2排放量最低,较传统竖炉降低15.35%,TGR2、TGR3流程CO2排放量分别上升0.16%和3.15%。

Theoretical analysis on top gas recycling of gas-based shaft furnace

To adequatly utilize chemical potential of the reducing gas in gas-based shaft furnace, three processes with top gas recycling(TGR) are established and a process model based on the mass and energy balance is developed to numerically analyze the advantages and disadvantages of the proposed processes. The results show that in the proposed TGR1, TGR2 and TGR3 cases, the demand of the fresh hot reducing gas decreases by 63.77%, 57.13% and 55.85%, respectively, and meanwhile the requirement of the corresponding sensible heat shows the same tendency. However, the consumption of energy in each process increasess by 5.68%, 7.27% and 17.12%, respectively, because of the additional cost of the gas reforming and preheating. The emission of CO2 for TGR1 decreases by 15.35% while the one for TGR2 and TGR3 increases by 0.16%, 3.15%, respectively.