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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KL的方法,并考察了两相流量对KL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KL的无因次准数关联,计算结果与实验结果符合良好.
In the T-shaped microchannels, micron-sized dispersed bubbles were prepared by cross-flow shear dispersion, and the CO2 absorption was taken as the object of NaOH aqueous solution. The dispersion and mass transfer properties of the gas-liquid micro- The influence of two-phase flow velocity on bubble dispersion size was investigated and a mathematical model for predicting bubble formation size was established.According to the initial bubble size, the volume change of flow phase and the size after mass transfer, the bubble formation phase and And the mass transfer rate during the motion phase, a method of in-situ determination of the mass transfer coefficient KL of bubble dispersion flow was established and the effect of two-phase flow on KL was investigated. The results show that due to the short formation time of bubbles in the microchannel, mass transfer The mass transfer coefficient of the bubble dispersion flow is mainly affected by the liquid flow rate and the influence of the gas phase flow rate can be neglected.Based on the experimental results, The correlations between the numbers are in good agreement with the experimental results.