T形微通道中气泡分散流的传质性能

在T形微通道中，以错流剪切的分散方式实现了微米级分散气泡的制备，并以NaOH水溶液吸收CO2为对象，考察了气．液微分散体系的分散规律和传质性能．通过考察两相流速对气泡分散尺寸的影响，建立了预测气泡形成尺寸的数学模型．根据气泡的初始分散尺寸、流动阶段的体积变化以及传质完成后的尺寸，首次测定和区分了气泡形成阶段和运动阶段的传质量，建立了原位测定气泡分散流传质系数札的方法，并考察了两相流量对札的影响．结果表明，由于微通道中气泡的形成时间很短，形成阶段的传质量在总传质量中所占的比例很低．气泡分散流的传质系数主要受液相流量的影响，气相流量的影响基本可以忽略．基于实验结果，建立了计算传质系数鼠的无因次准数关联，计算结果与实验结果符合良好．

Mass transfer performance of bubble flow in T-junction microchannel

The dispersion and mass-transfer performance of microbubbles in a T-junction microchannel was investigated in this study, with a gas-liquid system of CO2/NaOH aqueous solution. The influence of flow rates on the dispersion size of microbbles was studied and an equation was developed to characterize the dispersion size. The mass transfer performance during microbubble formation and movement in the microchannel was initially studied and an in-situ method was designed to determine mass-transfer coefficients. The results show that the amount of mass transfer during formation is low for the short formation time and the mass transfer performance during movement is mainly affected by the flow rate of liquid phase, while the influence of gas flow rate could be ignored. An empirical equation was established to quantitatively predict the mass-transfer coefficient, which is in good agreement with the experimental results.