面向转炉高废钢比冶炼工艺的废钢比与碳排放理论计算  

Theoretical calculation of scrap ratio and carbon emissions for high scrap ratio smelting process in BOF

作　　者：杨建平 姚柳洁 高攀 李海波 赵晓东[2] 孙永林[2] YANG Jianping;YAO Liujie;GAO Pan;LI Haibo;ZHAO Xiaodong;SUN Yonglin(Research Institute of Technology,Shougang Group Co.,Ltd.,Beijing 100043,China;Shougang Qian'an Iron and Steel Co.,Ltd.,Qian'an 064404,Hebei,China)

机构地区：[1]首钢集团有限公司技术研究院,北京100043 [2]首钢股份公司迁安钢铁公司,河北唐山064404

出　　处：《中国冶金》2023年第6期133-140,共8页China Metallurgy

摘　　要：提高转炉废钢比是降低高炉-转炉长流程碳排放的重要手段。为了定量评价不同废钢比提升工艺的降碳效果,基于热量平衡理论,构建面向预热废钢、添加补热剂、提高二次燃烧率3种常用废钢比提升工艺的废钢比与碳排放计算模型,并以国内某大型钢铁企业的A厂210 t转炉和B厂300 t转炉为例进行相关计算。研究结果表明,1000℃预热温度下,废钢烘烤热利用率对吨钢水CO_(2)排放量的影响是燃料燃烧热利用率的6.25倍,提高废钢烘烤热利用率更有利于吨钢水CO_(2)排放量的降低。A、B两厂使用硅质补热剂提升废钢比的效果优于碳质补热剂,但硅质补热剂碳排放因子较高,若热量利用率较低,可能会导致吨钢水CO_(2)排放量增加。A厂转炉二次燃烧率增大20%、燃烧热利用率为50%时,废钢比由基准态的15.0%提高至21.0%,吨钢水CO_(2)排放量由基准态的1.661 t降低至1.545 t。随着二次燃烧率的提高,燃烧热利用率对废钢比和吨钢水CO_(2)排放量的影响越发显著。Increasing scrap ratio in BOF is an important means to reduce the carbon emissions of long steelmaking process based on BF-BOF.In order to evaluate quantitatively the performance of scrap ratio lifting processes in carbon reduction,a mathematical model was built according to the theory of heat balance to calculate the scrap ratio and CO_(2) emissions for three common methods to increase scrap ratio,namely preheating scrap,adding heat supplement and increasing secondary combustion rate.The 210 t converter in A Plant and 300 t converter in B Plant for a large domestic iron and steel enterprise were made as examples for relevant calculations.The results show that the influence of the utilization rate of heat from scrap preheating on CO_(2) emission load of per ton molten steel can reach 6.25 times than that from fuel combustion for scrap preheating at the preheating temperature of 1 ooo C.Thus,raising the utilization rate of heat from scrap preheating is more favorable to reduce the CO_(2) emission load of per ton molten steel.The use of Si-based heat supplement is more effective to increase scrap ratio than that of C-based heat supplement in both A Plant and B Plant.Due to the high carbon emission factor of Si-based heat supplement,its low heat utilization rate in smelting process may lead to the increase of CO_(2) emission load of per ton molten steel.The scrap ratio of A Plant is increased from 15.0%to 21.0%,and the CO_(2) emission load of per ton molten steel is reduced from l.661 t to 1.545 t,when the secondary combustion rate is increased by 20%and the heat utilization rate is 50%.With the increase of secondary combustion rate,the effect of heat utilization rate is more significant on scrap ratio and CO_(2) emission load of per ton molten steel.

关 键 词：转炉废钢比 碳排放 理论计算 废钢预热 补热剂 二次燃烧 

分 类 号：TF713[冶金工程—钢铁冶金] X757[环境科学与工程—环境工程]