水煤浆气化炉三通道喷嘴气相流场的数值模拟

为研究三通道喷嘴结构对气化炉宏观冷态气相流场的影响,利用计算流体力学软件F luen t对水煤浆气化炉的三通道喷嘴和简单的单通道喷嘴分别在自由射流和受限射流情况下进行了气相流场的数值模拟。通过对两种喷嘴在自由射流和受限射流流场的比较,发现二者的流场非常相似,只是在距喷嘴出口较近处速度分布有明显不同。这说明喷嘴的结构对气化炉宏观气相流场的影响并不如入口速度对气相流场的影响显著。通过对喷嘴附近处径向和轴向速度分布的分析,发现三通道喷嘴外环气流和中心气流有强烈的撞击,这对水煤浆的雾化起到重要作用。

Numerical simulation of the gas flow field from a triple channel coal-water slurry gasifier nozzle

The influence of the design of a triple channel Texaco nozzle on the cold gas phase flow field in a gasifier was studied numerically by solving for the gas phase flow field produced by a triple channel Texaco nozzle and a single channel nozzle for both a free jet and a confined jet in a gasifier using Fluent.The result shows that the macro gas flow field produced by the Texaco nozzle is similar to that produced by the single channel nozzle.Obvious differences were only found near the nozzle outlet.Thus,the nozzle structure has less influence than the inlet velocity on the overall gasifier gas flow field.However,the analysis of the axial velocity and the radial velocity distribution near the nozzle outlet shows that for the triple channel nozzle,the enhanced mixing between the outside annular channel air flow and center channel air plays an important role in the coal-water slurry atomization process.