分级气流床气化炉模型研究

为了研究分级和气化炉结构对气化效果的影响,结合对分级气化炉内流动、燃烧和气化反应的分析,采用小室模型建立了分级气化炉的动力学模型,考虑了气化炉结构尺寸对气化过程和结果的影响。利用建立的模型,对等径结构、颈缩结构和渐扩结构3种形式的分级气化炉进行了计算,得到温度、气体组成及其体积分数、碳转化率等参数沿气化炉炉膛的分布情况,并和连续气化的结果进行了对比。结果表明氧气的分级给入加强了气化炉内的物料混和,提高了平均温度,有利于提高气化效率;同时最高点温度有所降低,有利于和延长耐火砖使用寿命。同样运行条件下分级气化得到的有效气体体积分数要高于连续气化。

Study on the modeling of staged entrained flow gasifier

In order to get a further understanding of the effect of different stage and gasifier structure on gasification results,based on the analysis of the flow,combustion and gasification reaction in the staged gasifier,a dynamic model for staged gasifier was built by using cell model.The effect of the gasifier structure on gasification process and result was considered in this model.Using this model,three types of staged gasifier named continued staged gasifier,necking staged gasifier and increasing coupling staged gasifier were calculated.The profile of the temperature,gas composition and its volume fraction,carbon conversion rate along the height of the gasifier were obtained,and the results were compared with that from continuous gasification.The comparison shows that the mixing of the material in the gasifier is enhanced and the average temperature is increased by staged oxygen injection,which is helpful to increase the gasification efficiency;at the same time,the highest temperature is decreased,which is beneficial to increase the service life of the refractory.CO H2 composition from staged gasifier is higher than that from continuous gasifier under the same operation condition.