A visual experiment is conducted to study bubble dimension characteristics during subcooled flow boiling in vertical flow channel with a round heating rod in a squared channel. With the high speed camera, the bubble behavior is captured and bubble dimension characteristics near the heating wall are obtained. In this study, the system pressure is from 0.1 to 1.0 MPa, the mass flux is from 800 to 1900 kg/m²s and the inlet subcooling is from 10 to 30 K. The effect of working conditions on bubble behavior is discussed in detail, such as system pressure, are analyzed in detail. The bubble dimension increases with increasing heat flux, while decreases with system pressure, inlet subcooling and mass flux. In order to predict bubble dimension better, a model is proposed based on important dimensionless numbers in this paper and good agreement is achieved when comparing with the experimental result.

通过视觉实验研究了方形通道中圆形加热棒在垂直流道中过冷流动沸腾过程中气泡的尺寸特性。使用高速摄像机捕捉气泡行为并获得加热壁附近的气泡尺寸特征。本研究中，系统压力为0.1～1.0 MPa，质量通量为800～1900 kg/m ²s，入口过冷度为 10 到 30 K。详细讨论了工作条件对气泡行为的影响，例如系统压力，详细分析了。气泡尺寸随着热通量的增加而增加，而随着系统压力、入口过冷度和质量通量而减小。为了更好地预测气泡尺寸，本文提出了一种基于重要无量纲数的模型，与实验结果比较吻合较好。