Abstract

The influence of pre-injection of a gas phase on gas–liquid two-phase flow through a vertical minichannel is experimentally investigated. Circular minichannel of 2 mm inner diameter is considered for the investigations. Air is used as a gas phase and water is used as a liquid phase. The superficial gas and liquid velocities are kept as 0.0531–0.2653 and 0.1062–0.2653 m/s, respectively. Inlet premixing of gas–liquid two-phase flow is achieved with an injector equipped with a nozzle to inject a gas phase. Three nozzles are developed with inner diameters of 0.7, 2, 2.5 mm. Direct injection and co-flow pre-injections of gas phase are obtained with various positions of a nozzle (0, 25 and 50 mm) in an injector. Flow patterns such as bubbly flow, Taylor bubble flow and slug-annular flow are observed and captured using an EXILIM high-speed camera. The influence of nozzle size and its positions in an injector on the hydrodynamics of Taylor bubble flow as well as two-phase pressure drop are analysed in detail. Inlet premixing and two-phase flow hydrodynamics have significant influence of gas-phase pre-injection in a vertical minichannel.

中文翻译：

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气相直接和共流预注入对通过垂直小通道的气液两相流的影响

摘要

实验研究了气相的预注入对通过垂直小通道的气液两相流的影响。考虑使用内径为2 mm的圆形微型通道。空气用作气相，水用作液相。气体和液体的表面速度分别保持为0.0531–0.2653和0.1062–0.2653 m / s。气液两相流的入口预混合是通过配备有喷嘴来喷射气相的喷射器实现的。开发了三个喷嘴，它们的内径分别为0.7、2、2.5 mm。在喷嘴中喷嘴的各个位置（0、25和50 mm）可实现气相的直接注入和并流预注入。使用EXILIM高速相机观察并捕获诸如气泡流，泰勒气泡流和团状环流等流型。详细分析了喷嘴尺寸及其在喷射器中的位置对泰勒气泡流动的流体动力学以及两相压降的影响。入口预混和两相流流体动力学对垂直小通道中的气相预注入有重大影响。