论文部分内容阅读
为了揭示喷射鼓泡反应器内流动结构和气液分散特性,为该反应器的优化设计提供理论指导,应用计算流体动力学（CFD）方法对反应器内气液两相流动结构进行了数值模拟,并提出气含率方差概念用于定量描述气相分散程度。着重考虑了搅拌转速和表观气速对通气功率、整体气含率和气相分散程度的影响。结果表明：流场的重要特征与前人的类似实验结果和数值模拟结果一致;数值模拟能很好地捕捉了六直叶圆盘涡轮桨的气穴现象;气穴现象会导致通气功率降低且不利于气液混合;整体气含率随转速和表观气速的增加而增大,但从气液混合与能耗的的角度考虑,搅拌转速宜采用200～300 r/min,表观气速为0.04～0.06 m/s。“,”Aiming to reveal the flow structure and gas-liquid dispersion in a jet bubbling reactor,and provide theoretical instruction for reactor design optimization.Computational Fluid Dynamics（CFD） was adopted to simulate the flow structure in the reactor;gas holdup variance was first proposed to quantitatively describe the gas dispersion.The effects of rotational speed and superficial gas velocity on gassed power consumption,overall gas holdup and gas dispersion were examined.The computed gas-liquid flow field agreed well with the experimental and numerical findings reported in the literature.The gas cavities behind the blades were reproduced by this simulation.It is indicated that the gas cavities significantly reduced the gassed power with respect to ungassed conditions and go against gas-liquid dispersion.Overall gas holdup was found to increase with rotational speed and superficial gas velocity.A rotational speed of 200~300 r/min and a superficial gas velocity of 0.04~0.06 m/s were proposed to adopt in accordance with the gas-liquid dispersion and power consumption.