Kesavan Sailesh, Eck Joakim, From Lars-Erik, Lundgren Maria, Sundqvist Öqvist Lena, Kjellberg Martin
Swerim AB, Box 812, 97125 Luleå, Sweden.
Konstruktionstjänst AB, Björkövägen 64, 97561 Luleå, Sweden.
Materials (Basel). 2025 Jun 27;18(13):3061. doi: 10.3390/ma18133061.
The blast furnace (BF) and basic oxygen route account for approximately 70% of the global steel production and create 1.8 tons of CO per ton of steel, produced primarily due to the use of coke and pulverized coal (PC) at the BF. With global pressure to reduce CO emissions, optimization of BF operation is crucial, which is possible through optimizing fuel consumption, and improving process stability. Understanding the complex combustion and flow dynamics in the raceway region is essential for enhancing reducing agent utilization. Modeling plays a key role in predicting these behaviors and providing insights into the process; however, validation of these models is crucial for their reliability but difficult in the complex and hostile BF raceway region. In this study, a validated raceway model developed at Swerim was used to evaluate four different cases, namely R1 (Reference), R2 (Low oxygen to blast), R3 (High blast moisture), and R4 (High PC) using an injection coal from SSAB Oxelösund. During actual experiments, the temperature distribution in the raceway was measured using a thermovision camera (TVC) to validate the CFD simulation results. The combined use aims to cross-validate the results simultaneously to establish a reliable framework for future parametric studies of raceway behavior under varying operational conditions using CFD simulations The results indicated that it is possible to measure the temperature within the raceway region using TVC at depths indicated to be 0.5-0.7 m, when not obscured by the coal plume, or <0.5 m, when obscured. TVC measurements are clearly quantitatively affected when obscured, indicated by considerably lower temperatures in the order of 200 °C between similar process conditions. A decrease of O injection results in an extended raceway region as the conditions become less chemically favorable for combustion due to a lower reactant content offsetting the ignition point and reducing the reaction rate in the raceway. An increased moisture content in the blast results in a reduced size of the race-way region as energy is consumed as latent energy and cracks water. An increase in PC rate results in a larger/wider raceway region, as more PC is devolatilized and combusted early on, resulting in larger gas volumes expanding the raceway region outwards, perpendicular to the injection.
高炉（BF）和碱性氧气转炉法约占全球钢铁产量的70%，每吨钢铁产生1.8吨二氧化碳，主要是由于在高炉中使用焦炭和粉煤（PC）所致。随着全球减少二氧化碳排放的压力增大，优化高炉操作至关重要，这可以通过优化燃料消耗和提高工艺稳定性来实现。了解风口回旋区复杂的燃烧和流动动力学对于提高还原剂利用率至关重要。建模在预测这些行为和深入了解该过程中起着关键作用；然而，验证这些模型对于其可靠性至关重要，但在复杂且恶劣的高炉风口回旋区却很困难。在本研究中，使用了在Swerim开发的经过验证的风口回旋区模型，以评估四种不同情况，即R1（参考）、R2（低鼓风氧气）、R3（高鼓风湿分）和R4（高粉煤），使用来自SSAB Oxelösund的喷吹煤。在实际实验中，使用热成像相机（TVC）测量风口回旋区内的温度分布，以验证计算流体动力学（CFD）模拟结果。联合使用旨在同时交叉验证结果，为未来使用CFD模拟在不同操作条件下对风口回旋区行为进行参数研究建立一个可靠的框架。结果表明，当未被煤羽遮挡时，可以在深度为0.5 - 0.7米处使用TVC测量风口回旋区内的温度，当被遮挡时，则在<0.5米处测量。当被遮挡时，TVC测量结果在数量上会受到明显影响，在类似工艺条件下，温度会显著降低约200℃。由于反应物含量降低抵消了着火点并降低了风口回旋区内的反应速率，鼓风氧气注入量的减少会导致风口回旋区扩大，因为此时燃烧的化学条件变得更不利。鼓风湿分增加会导致风口回旋区尺寸减小，因为能量以潜热形式消耗并分解水。粉煤比例增加会导致风口回旋区更大/更宽，因为更多的粉煤会提前挥发和燃烧，产生更大的气体体积，使风口回旋区垂直于喷吹方向向外扩展。
