新型气升式氧化沟流体力学特性的数值模拟  

Numerical simulation of the hydrodynamic characteristics of an innovative air-lift oxidation ditch.

作　　者：庞洪涛[1] 施汉昌[1] 施慧明 

机构地区：[1]清华大学环境模拟与污染控制国家重点联合实验室,北京100084

出　　处：《中国环境科学》2008年第5期438-443,共6页China Environmental Science

基　　金：国家"863"项目(2004AA601061)

摘　　要：以基于计算流体力学的FLUENT软件为工具,选用雷诺应力模型对小试气升式氧化沟的三维流场进行模拟研究,比较了进气量分别为0.25,0.5,0.75m3/h以及污泥浓度分别为2.5,5.0g/L时的流速和流态.结果表明,气升式氧化沟的流态从整体上看是完全混合的,但其底部由于流速较大又具有推流特性;进气量对液相流速影响明显,对整体流态并无影响,污泥浓度对流速和流态影响都很小;将模拟结果与实际测试数据对比,表明该模拟结果可靠,可用于小试反应器的流体力学特性研究.Based on the principle of computational fluid dynamics the flow characteristics of a bench-scale air-lift oxidation ditch was simulated by using FLUENT software and three dimensional Reynolds stress model. Hydrodynamic behaviors with different airflow rate, respectively 0.25,0.5,0.75m^3/h, and MLSS of 2.5g/L and 5.0g/L were compared. The flow pattern of the whole reactor was complete mixing, but plug flow characteristic appeared in the bottom area as relatively higher flow velocity. The airflow rate had obvious influence on flow velocity, and no influence on flow pattern. MLSS had little influence on flow velocity and flow pattern. Simulation results were compared with corresponding experimental data. The result indicated that numerical simulation was reliable, and could be used to investigate the hydrodynamic characteristics of bench-scale air-lift oxidation ditch.

关 键 词：气升式氧化沟 流体力学特性 数值模拟 

分 类 号：X703[环境科学与工程—环境工程]