The ironmaking blast furnace (BF) is an energy-intensive process, requires a considerable amount of carbon-related materials such as coke, coal, or natural gas, and releases enormous amounts of greenhouse gas (GHG). The oxygen enrichment operation is one promising technology to reduce the carbon footprint in the ironmaking process. However, the oxygen enrichment ratio (OER) varies significantly in practices, and the proper one is still unclear, especially in terms of fuel rate saving and in-furnace phenomena. In this study, a multi-fluid BF model is used to quantitatively study the influence of oxygen enrichment on the BF process in terms of bosh gas volume, top gas composition, and inner thermochemical behaviors of solid–gas–liquid phases. Under the simulation conditions, the results show that for every increase of OER, the blast rate is decreased by ~ 85 m3/min and nitrogen content in reducing gas is decreased by ~ 1.13 pct; also, the top gas temperature is lowered by ~ 17 K, and the flame temperature is increased by 58.4 K. Descending of cohesive zone (CZ) inside the BF is observed with the region volume ratio decreased by ~ 0.102; the chemical reserve zone of wustite becomes much narrower and lower inside the BF, but does not disappear. The potential of carbon footprint mitigation in the BF process is discussed with the optimal OER recommended, 7.5 pct under the present simulation conditions. This model can help to build a comprehensive understanding of the fuel rate saving and CO2 emission reduction of a BF adopting an oxygen enrichment operation.

中文翻译：

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富氧炼铁高炉热化学行为的计算流体动力学研究

炼铁高炉 (BF) 是一个能源密集型过程，需要大量的碳相关材料，如焦炭、煤或天然气，并释放大量的温室气体 (GHG)。富氧操作是减少炼铁过程中碳足迹的一项有前途的技术。然而，富氧比（OER）在实践中存在较大差异，目前尚不明确，尤其是在节油和炉内现象方面。在本研究中，多流体 BF 模型用于定量研究富氧对 BF 过程的影响，包括主气体积、炉顶气组成和固-气-液相的内部热化学行为。在模拟条件下，结果表明，OER 每增加一次，风速降低~85 m3/min，还原气体中的氮含量降低~1.13 pct；此外，炉顶气体温度降低~17 K，火焰温度升高58.4 K。观察到高炉内部的凝聚区（CZ）下降，区域体积比降低~0.102；高炉内方铁矿的化学储备区变得更窄和更低，但并没有消失。BF 过程中碳足迹减缓的潜力与推荐的最佳 OER 进行了讨论，在当前模拟条件下为 7.5%。该模型有助于全面了解采用富氧操作的高炉的节油和CO2减排。炉顶气体温度降低~17 K，火焰温度升高58.4 K。观察到高炉内部的凝聚区（CZ）下降，区域体积比降低~0.102；高炉内方铁矿的化学储备区变得更窄和更低，但并没有消失。BF 过程中碳足迹减缓的潜力与推荐的最佳 OER 进行了讨论，在当前模拟条件下为 7.5%。该模型有助于全面了解采用富氧操作的高炉的节油和CO2减排。炉顶气体温度降低~17 K，火焰温度升高58.4 K。观察到高炉内部的凝聚区（CZ）下降，区域体积比降低~0.102；高炉内方铁矿的化学储备区变得更窄和更低，但并没有消失。BF 过程中碳足迹减缓的潜力与推荐的最佳 OER 进行了讨论，在当前模拟条件下为 7.5%。该模型有助于全面了解采用富氧操作的高炉的节油和CO2减排。高炉内方铁矿的化学储备区变得更窄和更低，但并没有消失。BF 过程中碳足迹减缓的潜力与推荐的最佳 OER 进行了讨论，在当前模拟条件下为 7.5%。该模型有助于全面了解采用富氧操作的高炉的节油和CO2减排。高炉内方铁矿的化学储备区变得更窄和更低，但并没有消失。BF 过程中碳足迹减缓的潜力与推荐的最佳 OER 进行了讨论，在当前模拟条件下为 7.5%。该模型有助于全面了解采用富氧操作的高炉的节油和CO2减排。