Experimental Study Of Gas-liquid Two-phase Flow Division In Microchannel Branching Conduits

Microchemical technology attracted vast attention since it has been brought forward, dueto advantages, such as high efficiency, rapidity, flexibility and high degree of integration. Asthe basis for studying and applying the microchemical technology, gas-liquid two-phase flowbehaviors in microchannels became the research hotspot. Although related papers are endless,the majority of the studies are performed using a single micro-channel, investigations ongas-liquid two-phase flow in microchannels of complex construction, microchannel branchingconduits, for instance, are relatively few. Different from the single microchannel, when agas-liquid two-phase flow passes through a microchannel branching conduits, unevendistribution of the phases will take place between the outlets. The occurrence of thismal-distribution may have a significant influence on the performance of equipments.Therefore, an experimental investigation on the phase split of gas-liquid two-phase flowoccurring at the horizontal branching conduits with hydraulic diameter of500μm wasconducted in this work.Experiments were carried out at room temperature and atmospheric pressure. Themicrochannel branching conduits with three equal arms were made from polymethylmethacrylate rectangular block to allow visual observations. As expected, mal-distributionphenomenon was observed according to the visual investigations. The effect of inlet flowconditions, fluid property and geometric parameters on the characteristics of gas-liquidtwo-phase flow splitting through the microchannel branching conduits was investigated, inorder to further understand this phenomenon.Using the fractions of gas and liquid flow taken off through the side arm as coordinates,figures representing phase separation results were drawn. It showed by comparisons of thisfigures as follows.(1) The fraction of liquid taken off into the side arm increases with the increase of gassuperficial velocity while decreases with the increase of liquid superficial velocity.(2) The phase splitting characteristics for various flow patterns are different.(3) Both the properties of non-Newtonian fluid and angle between the outlets haveinfluence on phase distribution, but the effect depends on the inlet flow patterns.