新型两段式气化炉的数值分析

Numerical simulation analysis of novel two-stage gasifier

对一种新型两段式水煤浆气化炉的气化效率进行了数值计算和分析。模型中将水煤浆的气化过程分为水分蒸发、煤热解、气相反应和气固异相反应等子模型。气相反应速率需同时考虑湍流混合和化学反应机理,气固反应的速率采用未反应缩芯模型。运用可实现k-ε模型描述气相湍流流动,随机轨道模型追踪水煤浆颗粒的运动。以中试多喷嘴水煤浆气化炉为建模基础,验证了该水煤浆气化模型的准确性。模拟计算得出新型两段炉的有效气组分含量为85.91%,冷煤气效率为76.42%。

The gasification efficiency of a novel two-stage gasifier was studied and analyzed by numerical simulation.In this model the coal-water slurry（CWS）gasification process was divided into several sub-models：water droplet evaporation,coal pyrolysis,gas homogeneous reaction and gas-solid heterogeneous reaction.Turbulent flow mixing and chemical reaction were considered in the rate of gas phase reaction.The unreacted-core shrinking model was used to describe the rate of gas-solid heterogeneous reaction.The realizable k-ε turbulence model was used for the gas phase flow,and coal-water slurry particles were tracked by the Random-Trajectory model.The CWS gasification model was verified based on the model subject of a pilot-scale opposed multi-burner（OMB）gasifier.The simulation result showed that effective gas composition of the novel two-stage gasifier was 85.91%,and cold gas efficiency was 76.42%.