Optimal Operation of Electric Arc Furnaces to Minimize the Generation of Air Pollutants at the Source

摘要- Ramirez - 9816804 在美国，通过电弧炉（EAF）制造钢的使用持续增加，目前的产量估计超过每年6300万吨。 长期以来，钢铁工业一直因其对该国空气污染的贡献而闻名。 钢铁生产商减少排放量的工作进展缓慢，主要有两个原因：需要维持或提高目前的生产水平，以及对炼钢过程缺乏了解和控制。 电弧炉保持液体（钢水）、炉渣（金属氧化物）和气体的三相系统，在这三者之间发生质量和热量传递。 炉操作或控制包括碳注入、氧兰辛、燃烧器操作和空气渗透。 控制器用于在所需温度下生产适当等级的钢水。 PI已经开始开发电弧炉的动态模型，包括熔化、平衡化学和物料平衡子模型。 EAF模型包括工业炉中涉及的所有炉操作。 对炉子控制的初步研究表明，该系统对碳喷射和燃烧器氧气控制非常敏感，从而使一氧化碳排放量最小化。 这些结果显示出改善炉性能的巨大希望，包括环境影响和能源消耗。 在四家工业公司（包括两家钢铁生产商）的合作下，研究人员计划进行一项为期三年的研究计划，其中包括模型验证和校准，将NOx化学添加到模型中，以及使用动态规划和变分法对过程进行动态优化。 这解决了EPA的常识倡议，为钢铁工业寻找更好的环保生产方法。 研究的最终结果将是一个闭环优化控制系统，可以最大限度地减少环境影响和能源消耗，同时保持盈利能力。 该项目将导致电弧炉的操作政策，通过在源头尽量减少空气污染物的产生来防止污染。

Abstract - Ramirez - 9816804 The manufacture of steel by electric arc furnaces (EAF) is continuing to increase in usage in the United States with current production estimated to be over 63 million tons per year. The steel industry has long been known for its contributions to air pollution in this country. The reduction of emissions from steel producers has been slow for two main reasons: the need to maintain or increase current production levels and the lack of understanding and control of the steel-making process. The EAF holds a three-phase system of liquid (molten steel), slag (metal oxides), and gas with both mass and heat transfer taking place amongst the three. The furnace operations, or controls, include carbon injection, oxygen lancing, burner operation, and air infiltration. The controls are used to produce the appropriate grade of liquid steel at a requested temperature. The PI has begun the development of a dynamic model of the electric arc furnace consisting of melting, equilibrium chemistry, and material balance sub-models. The EAF model includes all of the furnace operations involved in an industrial furnace. Preliminary investigations into the control of the furnace minimize carbon monoxide emissions have shown that the system is extremely sensitive to carbon injection and burner oxygen controls. These results show great promise for the improvement of furnace performance, which includes environmental impact and energy consumption. With the collaboration of four industrial companies, including two steel producers, the investigator plans a three year research program which includes model verification and calibration, the addition of NOx chemistry to the model, and dynamic optimization of the process using dynamic programming and the calculus of variations. This addresses the EPA's Common Sense Initiative toward finding better environmental production methods for the steel industry. The final result of the research will be a closed-loop optimal control system that can minimize environmental impact and energy consumption while maintaining profitability. This project will lead to operational policies for electric arc furnaces that allows for pollution prevention by minimizing the generation of air pollutants at the source.