微通道气液两相流型及界面面积测定

Flow pattern and gas-liquid interfacial area in a microchannel contactor

以氢氧化钠水溶液及纯二氧化碳气体为工质，研究了石英玻璃微通道中的气液两相流流型及两相界面面积。实验中可清晰分辨的流型为弹状流（Slug），弹状一环状流（Slug—annular）及搅拌流（Churn），由实验观测的结果建立了相应的流型图并与Triplett实验结果进行了比较，结果表明高液相表观流速对流型转换影响较大。在微通道中可以实现比较高的气液两相界面面积，实验范围内气液两相界面面积高达5070m^2／m^3。两相界面面积随气相表观流速的增加而增加，而液相表观流速对两相界面面积的影响则不显著。相对于弹状流区域，在弹状一环状流及搅拌流区域可以实现比较高的传质界面面积。搅拌流区域气液两相界面面积可以采用气液表观雷诺数进行很好关联，其绝对平均偏差仅为3．76％。

With aqueous solutions of sodium hydroxide and carbon dioxide as the working fluids, the flow patterns and the gas-liquid interface in a quartz microchaanel contactor are investigated. The discernable flow patterns are slng, slug-annular and churn. Based on the experimental data, the flow pattern map is developed and compared with the Triplett＇s correlations. It shows that the flow pattern transition is affected by the mass transfer especially when the supeficial liquid velocities are high. As high as 5 070 m2/m3, the microchannel contactor can provide a high gas-liquid interface area. The gas-liquid interface area increases with the increase of superficial gas velocities while the influence of superficial liquid velocities is not marked. Compared with the slug flow, a higher gas-liquid interface area can be achieved with a slug-annular and churn flow. The interface area can be well correlated with the superficial reyndds number for churn flow and the absolute mean deviation is only 3.76%.