生物反应器内不同桨叶组合计算流体力学模拟

Computational fluid dynamics simulation of different impeller combinations in bioreactor

运用计算流体力学(CFD)数值模拟方法研究在相同工况下(搅拌桨转速为400 r/min、通气速度为0.86 vvm和操作温度为15℃),4种不同桨叶组合方式对5 L气液生物反应器流场、氧传质系数kLα、空气体积分数、气含率(体积分数)和功率的影响,评判各桨叶组合综合性能。计算结果表明:1号方案上下档均为径向桨,具有最高kLα提供能力;上档为轴向桨,下档为径向桨的2、3号组合,有较好的混合和分散气泡的能力;上下档均为轴向桨的4号方案有着较低能耗,约为0.2 W/L。

The influence of 4 kinds of different impeller combination on flow patterns,oxygen mass transfer coefficient kLα,air volume fraction,gas holdup（volume fraction） and power in a gas-liquid bioreactor was studied under the same operating conditions（rotation rate of impellers 400 r/min,gas rate 0.86 vvm and operating temperature 15 ℃） using computational fluid dynamics（CFD） numerical simulation method.The research results show that the Model 1 which has the radial flow impellers at both the top and bottom sides can provide the highest capacity of kLα.Meanwhile,the Model 2 3 with the assembled axial flow impeller at the top and the radial follow impeller at the bottom,have a better ability to mix the liquid and disperse bubbles.Compared with other three models,the Model 4,with the axial flow impellers at both top and bottom sides has lower power consumption,approximately 0.2 W/L.