摘要
在“双碳”背景下,高温氧化球团的余热回收成为钢铁生产的一个节能潜力点.采用氢气将热态氧化球团冷却,可提高球团的金属化率,降低后续冶炼工序的能量需求.本文中采用数值模拟方法,分析了冷却气流量及其氢气占比对球团冷却行为、金属化率、能量利用率及气体利用率的影响,同时还利用热态实验探索了冷却气对预还原球团冶金性能的影响.结果表明:适宜的冷却气流量可提升预还原球团的金属化率、能量利用效率和冷却气的利用率,过量的冷却气会导致降温过快,从而减少化学反应吸热,使金属化率下降;随着冷却气中氢气占比的增大,金属化率升高,但能量利用效率和冷却气利用率均降低;当采用纯氢冷却、气流量(标准状况下冷却1 t氧化球团)为800 m^(3)/t时,炉内气流分布均匀,冷却效果最优,预还原球团的金属化率、[火用]效率、冷却气利用率分别为31.5%,23.48%和26.4%;纯氢条件下冷却得到的预还原球团金属化率、抗压强度、转鼓指数分别为34.77%,1902 N/个和98.21%,其抗压强度和转鼓指数均满足后续生产需求.
Against the backdrop of the dual carbon goals,waste heat recovery from high-temperature oxidized pellets presents a significant energy-saving opportunity in steelmaking.Utilising hydrogen to cool hot oxidized pellets enhances pellet metallization rates while reducing energy requirements in subsequent smelting processes.Numerical simulation methods have been employed to analyze the influence of cooling gas volume and hydrogen concentration on pellet cooling behaviour,metallization rates,energy utilisation efficiency,and gas utilisation efficiency.Hot-state experiments are also conducted to explore the effect of cooling gas on the metallurgical properties of pre-reduced pellets.Results indicate that an appropriate cooling gas flow rate enhances the metalization rate,energy utilisation efficiency,and cooling gas utilisation rate of pre-reduced pellets.Excessive cooling gas,however,reduces the endothermic chemical reactions due to overly rapid cooling,thereby decreasing the metalization rate.As the hydrogen proportion in the cooling gas increases,the metalization rate rises,but both energy utilisation efficiency and cooling gas utilisation rate decrease.Under pure hydrogen cooling at a gas volume of 800 m^(3)/t,uniform gas distribution within the furnace yielded optimal cooling performance,with the pre-reduced pellets achieving metalization rates,energy efficiency,and cooling gas utilisation rates of 31.5%,23.48%,and 26.4%,respectively.The pre-reduced pellets cooled under pure hydrogen conditions achieve a metalization rate of 34.77%,compressive strength of 1902 N/pellet,and drum index of 98.21%,respectively.Both compressive strength and drum index meet subsequent production requirements.
作者
储满生
董俊龙
李峰
唐珏
田宏宇
Chu Mangsheng;Dong Junlong;Li Feng;Tang Jue;Tian Hongyu(Engineering Research Center of Advanced Technology of Low Carbon Steel,Ministry of Education,Shenyang 110819,China;School of Metallurgy,Northeastern University,Shenyang 110819,China;Liaoning Engineering Research Center of Advanced Technology of Low Carbon Steel,Northeastern University,Shenyang 110819,China)
出处
《材料与冶金学报》
北大核心
2025年第5期476-486,共11页
Journal of Materials and Metallurgy
基金
国家自然科学基金项目(U23A20608,ZX20230376)
国家资助博士后研究人员计划项目(GZC20230392)
中央高校基本科研业务费项目(N2025023,N25ZJL011)
辽宁省科技计划联合计划项目(2023-BSBA-109).
关键词
氧化球团
氢气冷却
数值模拟
金属化率
oxidized pellets
hydrogen cooling
numerical simulation
metalization rate
