ABSTRACT

A three-dimensional computational fluid dynamics (CFD) model for the HIsarna off-gas system is set up and validated by real plant data. In the model detailed reaction mechanism and kinetic data for post-combustion of CO-H2 mixture and carbon particles are incorporated. The results are presented and discussed in another study (Part 1) by the same authors. In the present paper, the focus will be on geometry modification of the off-gas system and the effects on the operating parameters. The effect of this modification on heat loss, temperature profile, carbon conversion and gaseous phase composition across the off-gas system is investigated. It is shown that the modified geometry leads to a higher heat loss through the reflux chamber walls which can change the temperature profile and consequently species composition. The modified geometry also offers possibility of higher CO-H2 mixture and carbon particles conversion rate and reduce unwanted emission from the reflux chamber.

摘要

HIsarna 尾气系统的三维计算流体动力学 (CFD) 模型由实际工厂数据建立和验证。在模型中，包含了 CO-H2 混合物和碳颗粒后燃烧的详细反应机理和动力学数据。结果在同一作者的另一项研究（第 1 部分）中进行了介绍和讨论。在本文中，重点将放在废气系统的几何形状修改和对操作参数的影响上。研究了这种修改对废气系统的热损失、温度分布、碳转化和气相组成的影响。结果表明，修改后的几何形状导致通过回流室壁的热损失更高，这可以改变温度分布并因此改变物种组成。