电炉烟气流场特性及排风系统优化研究
Flow field characteristics of flue gas and exhaust system optimization in electric furnace
摘要：
利用CFD数值模拟的方法对某钢厂产生的高温烟气在原排风系统下的流场特性及烟气的捕集情况进行了研究，提出了在原侧吸罩基础上增加顶部吸气罩的优化方案。在保证排风系统总风量不变的前提下，模拟分析了采用5种不同顶吸风量时厂房内的流场分布情况，并比较了不同风量下的烟气捕集效率。研究发现：在原排风系统的作用下，高温烟气卷吸环境空气在厂房内形成温度与浓度分层，侧吸罩对烟气的捕集效率为61.7%；增加顶部吸气罩后，厂房内纵向烟气温度随高度的增加衰减加快，水平方向上烟气的扩散量减少；采用顶部吸气罩风量为40万m3/h，侧吸罩风量为21万m3/h的排风形式，捕集效率接近80%。通过分析高温烟气的流场特性及排烟系统捕集效率，对电炉炼钢排风系统的优化设计给出了建议。
Abstract：
Applies the CFD numerical simulation method to study the flow field characteristics and the gas collection of the high temperature flue gas produced in a steel plant using the original exhaust system, and proposes an optimal scheme of adding a top suction hood on the original suction hood system. Ensuring the consistent total air flow rate of the exhaust system, simulates and analyses the flow fields at five different top suction air flow rates in the factory building, and compares the flue gas collection efficiency at different air flow rates. The results show that with the effect of the original exhaust system, high temperature flue gas entrains ambient air in the factory building and forms a temperature and concentration stratification, the flue gas collection efficiency of the side suction hood is 61.7%; When adding the top suction hood, the longitudinal smoke temperature in the workshop increases with the increase of height, and the diffusion of flue gas in the horizontal direction decreases. The air flow rates are 400 000 m3/h and 210 000 m3/h for the top suction hood and the side suction hood, respectively, with the almost 80% of collection efficiency. By analysing the flow field characteristics of high temperature flue gas and the collection efficiency of the flue gas exhaust system, suggests an optimal design for the exhaust system of the electric furnace steelmaking.
Keywords:high temperature flue gas, flow field characteristic, side suction hood, top suction hood, exhaust system optimization, collection efficiency