摘要
为研究顶置七喷嘴气化炉流场情况,基于相似准则设计并模拟工业规模干粉气化炉条件,采用激光多普勒动态分析仪(PDA)在高4 000 mm、直径800 mm的模型炉中测定了顶置七喷嘴的速度场分布,并与单喷嘴速度场进行对比。结果表明:单喷嘴偏向于中心射流,而顶置七喷嘴轴向速度沿径向分布速度剪切小,更倾向于平推流,且顶置七喷嘴中心轴向速度衰减快,颗粒不易"短路"。此外,相比单喷嘴而言,顶置七喷嘴回流区域更小且中心气固混合效果更好。而通过计算出的回流比结果表明,顶置七喷嘴在喷嘴出口附近的回流比较高,能有效促进气化剂与燃料的混合,提高气化碳转化率。
In order to investigate the flow field of the top-setting seven-nozzle gasifier, a model gasifier was designed based on the similari- ty principle with the height of 4 000 mm and the diameter 800 mm based on industrial dry-coal fed gasifiers. The velocity fields were measured using PDA for the top-setting seven-nozzle scheme and top-setting single-nozzle scheme,respectively. The results indicate that the top-setting single-nozzle scheme has a center-jet flow field, but the top-setting seven-nozzle scheme is of a plug-flow like field with much less axial velocity degradation along the radial direction. In addition ,the center velocity of the top seven-nozzle scheme reduces more dramatically than that of the top-setting single-nozzle scheme resulting in fewer short-way particles. The top-setting seven-nozzle scheme has much smaller reflux zone and better gas-solid mixing effects that the top-setting single-nozzle scheme. The calculated reflux ratio of particles near the nozzle exit positions of the top-setting seven-nozzle scheme is higher than that of the top-setting single-nozzle scheme, which indicates that the top-setting seven-nozzle scheme can effectively enhance the gas-solid mixing and improve the carbon conversion efficiency.
作者
彭宝仔
刘臻
管清亮
方薪晖
李文华
PENG Baozai;LIU Zhen;GUAN Qingliang;FANG Xinhui;LI Wenhua(National Institute of Clean-and-Low-Carbon Energy,Beijing 102211, China)
出处
《洁净煤技术》
CAS
2017年第6期51-55,共5页
Clean Coal Technology
基金
神华集团科技创新资助项目(SHJT-14-53)
关键词
气化
冷态
顶置七喷嘴
速度分布
回流比
gasifition
cold model
top-setting seven-nozzle
velocity field
reflux ratio
