Abstract: A comprehensive three dimensional numerical model has been developed for the GSP gasifier. Based on the assumption of chemical equilibrium, two mixture fractions, f_fuel and p_sec, are used to describe the thermochemistry of the gasifier. Probability density function (PDF) is used to describe the coupling of turbulence-chemistry. Stochastic tracking technique is selected to describe the interaction of turbulence and particle motion. The predictions are in good agreement with experimental data and literature, proving the reliability of the model. The flow field of GSP gasifier can be divided into four regions: swirling jet region, internal recirculation region, external recirculation region and plug flow region. Oxidation reactions are mainly conducted in swirling jet region and internal recirculation region. Gasification reactions dominate the other regions. The high temperature flame impinge directly on the chamber wall of the 1/3 height of the gasifier, so more consideration should be taken on the protection of the refractory at that position.

Key words: numerical simulation, swirling jet, model, gasification

摘要： GSP气化炉是国内最近引进的西门子公司开发的粉煤气化技术，由于对其炉膛内气固反应流动特性认识不足，运行中出现耐火砖烧穿、合成气含灰过高等问题。利用数值模拟方法，采用双组分PDF模型耦合湍流-化学反应、随机轨道法耦合湍流-颗粒运动，针对GSP气化炉内多相反应流场建立三维数值模型。计算结果与实验值及文献计算结果一致，表明该模型可用于GSP气化炉的模拟计算。研究发现，炉膛内流场主要分为旋转射流区、内回流区、外回流区和管流区。高温区位于发生氧化反应的旋转射流区和内回流区上部，而外回流区和管流区主要发生还原反应，温度较为均匀；炉膛高度1/3位置处为高温火焰直接冲刷处，在运行时需重点考虑该位置的热防护。

关键词: 数值模拟, 旋转射流, 模型, 气化