液氮在弦月形狭缝通道内沸腾传热的可视化实验研究

Visual Observation and Experimental Study on the Two-phase Flow Boiling Heat Transfer of Liquid Nitrogen in Lunate Channel

采用可视化实验方法研究液氮在弦月形狭缝通道内两相流流动和传热现象。利用精心设计和制作的试件,借助高速摄影仪和3CCD 数码摄像机,获得了液氮在弦月形狭缝通道热虹吸沸腾时的气泡行为及两相流动的真实信息。实验观察到在狭缝通道中,气泡总是首先出现在接触线处;气泡发生很大变形,呈扁片状;弦月形狭缝通道热虹吸两相流动是一种振荡流。文中定义了弦月形通道内热虹吸沸腾的五种两相流流型。实验结果表明,弦月形狭缝通道具有强化传热效果。该实验研究对于分析弦月形狭缝强化传热的特性和机理,无论在学术研究方面还是在工程应用方面,都有着一定的价值和意义。

Cryogenic two-phase flow and boiling heat transfer characteristics are studied by means of visualized experiment in lunate narrow channel. It is found that bubbles initially appear at connected line and then are deformed into plume form. The thermosyphon two-phase flow in lunate channel is a kind of fluctuation flows. Five two-phase flow regimes are defined. Stimulation phenomenon of heat transfer is found and discussed.