通道尺寸对竖直向上气-水两相流流型影响实验研究

Experimental Study on Effect of Channel Size on Upward Air-Water Two-Phase Flow Regimes in Vertical Channels

本文以空气和水为工质,对竖直向上矩形通道(40mm×1.41mm,40mm×10mm)和圆形通道(D=25mm)内的两相流流型特性进行了可视化研究。气液两相的表观速度分别为:0.03～24.71m/s和0.03～3.73m/s。3个实验段内均出现了泡状流、弹状流、搅混流和环状流4种流型,40mm×10mm和圆形通道中流型特征较为接近,与40mm×1.41mm通道中流型相比存在明显差别。此外,绘制出了3种通道详细的流型图。对比结果显示,矩形通道窄边宽度对流型转变有显著的影响,随着矩形通道窄边宽度的增加,其流型转变边界更加趋近于圆形通道。

A visualized study of flow patterns was carried out for air-water two-phase flow in two narrow rectangular ducts（40 mm×1.41 mm,40 mm×10 mm） and a circular tube with a diameter of 25 mm,respectively.The superficial velocity air and water were in the range of 0.03-24.71 m/s and 0.03-3.73 m/s.All the bubble,slug,churn and annular flows occurred in the three channels.Characteristics of flow patterns in the 40 mm×10 mm duct are very similar to those in circular tube,but different from the 40 mm×1.41 mm duct.Detailed flow regime maps of the three channels were presented.The experimental results show that the channel size has a significant influence on flow pattern transition,boundary of which in rectangular channels tends asymptotically towards that in the circular tube with increasing the width of narrow side.