过冷流动沸腾气泡生成状态的可视化实验研究

Visualization Experiment for Bubble Generation of Subcooled Flow Boiling

采用CCD高速摄像技术和数字图像处理技术,针对各种操作条件和加热面结构下的过冷沸腾气泡生成状态进行了可视化的实验研究。讨论了流场、主体温度、热流密度、加热面结构、加热面材质等对过冷沸腾传热的影响。结果显示,随主体流量增大,气化核心密度和气泡Satuer直径呈减小趋势,但当流量增加到一定程度,两者均变得与主体温度无关;随热流密度增加和过冷度减小,气泡S砒uer直径随之增加;加热面材质对气泡粒径无太大影响。根据试验数据和分析结论提出了沸腾气泡Satuer直径经验公式。

Using CCD high-speed video technology and digital image processing technology, a visualization experiment for bubble generation of subcooled flow boiling under various operating conditions and heating surface structures are carried out. The influence of flow field, temperature, heat flux, heating surface structure and material of heating surface on the heat transfer of subcooled cooling boiling is discussed. The results indicate that with the increase of main flow, the gasification core density and the bubble Sauter diameter show a decrease tendency, however, when the flow increased to a certain degree, both become have nothing to do with the body temperature. With the increase of heat flux and the decrease of the subcooled temperature, Satuer diameter also will increase. Heating surface material has no effect on the particle size of the bubble. According to the experimental data and the above conclusions, an empirical formula of Satuer diameter for boiling bubble is presented.