高炉喷吹COREX脱CO2顶煤气的数值分析

 COREX脱CO₂顶煤气作为一种优质富氢气体,直接喷吹进入高炉可有效降低高炉燃料消耗。建立了高炉喷吹COREX脱CO₂顶煤气静态工艺模型,研究高炉喷气对风口理论燃烧温度、炉腹煤气量、炉腹煤气成分、风口回旋区形状、直接还原度、节焦效果等因素的影响,并进一步探究了提高风温作为热补偿措施后的适宜喷气量。研究结果表明,不采取热补偿措施条件下,随着COREX脱CO₂顶煤气喷吹量的增加,理论燃烧温度逐渐降低,炉腹煤气量逐渐升高,高炉直接还原度降低。以维持理论燃烧温度和炉腹煤气量稳定为标准,风温相对基准提高30、60、90 ℃后,可接受喷吹的煤气量为45.4、85.5、123.3 m3/t。热补偿后,随着喷气量增加,鼓风量逐渐降低,富氧率逐渐升高。炉腹煤气中的CO及H₂含量随喷气量增加而增加,每增加10 m3/t的COREX煤气喷吹量,炉腹煤气中总的还原气体体积分数增加0.46 %,直接还原度降低0.006,节约焦炭1.48 kg/t。

Numerical simulation of injection of COREX decarbonized top gas to blast furnace

COREX decarbonized top(CEG),as a high-quality hydrogen-rich gas,directly injected into blast furnace can effectively reduce the fuel consumption.A static model of blast furnace operation of CEG was developed.The effects of CEG injection on the raceway adiabatic flame temperature(RAFT),the amount and composition of bosh gas,the shape of raceway,the direct reduction degree,and the coke saving effect were studied.Furthermore,the acceptable quantities of CEG after increasing the blast temperature as a thermal compensation measure was investigated.The results showed that under no thermal compensation,with the increase of CEG injection,the RAFT decreases but the volume of bosh gas increases.The direct reduction degree decreases with the increase of CEG injection.Based on the standard of maintaining the RAFT and volume of bosh gas,when the blast temperature is increased by30,60,90℃,the corresponding suitable CEG injection volume is 45.4,85.5,123.3 m³/t,respectively.After thermal compensation,with the increase of CEG injection,the blast volume decreases but the oxygen enrichment rate increases.The CO and H2 contents in the raceway increased with the increase of the injection volume of CEG.For every 10 m³/t increase of CEG injection volume,the reducing content in bosh gas is increased by 0.46 %,the direct reduction degree decreases by 0.006,and the coke is saved by 1.48 kg/t.