Abstract:

According to the flow field of opposed multi-burner gasifier, the gasifier was divided into several regions.The particle residence time distribution (RTD) in the gasifier was investigated with a stochastic model based on discrete time and state Markov chain.The results showed that the calculated results could give a reasonable fit to the experimental data when reflux ratio between jet stream region and impinging region was 0.5, the tube stream region and the downward impinging-stream region were regarded as plug flow reactor (PFR), others were considered as continuous stirred tank reactor (CSTR).Mean residence time and dimensionless variance decreased with the increase of flow rate, while mean residence time increased with the increase of reflux ratio.Mean residence time was similar between gaseous phase and solid phase.

摘要：

根据多喷嘴对置式气化炉流场测试，将气化炉划分为若干区域，运用时间离散、状态离散的马尔可夫链随机模型，模拟了气化炉内颗粒相的停留时间分布(RTD)。当颗粒在撞击区和射流区间的回流比为0.5，向下撞击流股区和管流区为平推流模型，其他区域按全混流模型处理时，模拟值与实验值吻合较好。随着进料流量的增大，平均停留时间减小，量纲1方差减小；随着回流比的增加，平均停留时间增大；气固两相平均停留时间接近，但RTD存在一定差异。