Entrained droplets play an important role in heat and mass transfer in annular flow, but there are few studies on droplet size of annular flow in narrow rectangular channels. In this paper, we use the HELOS/KR Vario particle size analyzer to measure droplet size of vertically upward annular flow in a narrow rectangular channel. The results show that the Sauter mean diameter of droplets in narrow rectangular channel decreases with increasing gas velocity and increase with the increase of liquid velocity. Meanwhile, the distribution of droplet sizes has two types: single-peaked distribution and double-peaked distribution. Furthermore, we propose a correlation that can predict the droplets Sauter mean diameter of annular flow in a narrow rectangular channel.

夹带液滴在环形流中的传热传质中起重要作用，但关于窄矩形通道中环形流液滴尺寸的研究很少。在本文中，我们使用 HELOS/KR Vario 粒度分析仪来测量窄矩形通道中垂直向上环形流的液滴尺寸。结果表明，窄矩形通道中液滴的Sauter平均直径随着气体速度的增加而减小，随着液体速度的增加而增加。同时，液滴尺寸的分布有两种类型：单峰分布和双峰分布。此外，我们提出了一种相关性，可以预测狭窄矩形通道中环形流的液滴 Sauter 平均直径。