高热流条件下翅片凹腔内超汽化换热的微距PLIF观测

Hypervapotron flow in cavities of fin mockups measured with macrophotographic PLIF under high heat flux conditions

在已建成的兆瓦每平方米量级高热流密度超汽化实验平台上,采用平面激光诱导荧光(Planar laser induced fluorescence, PLIF)和微距高速摄影技术,观察了过冷水在三角形翅片和矩形翅片凹腔内的超汽化换热流动现象,包括汽泡的生成、吸附、脱落、汇聚及破碎等行为特征,测量了翅片凹腔中心对称切面的温度场,分析了不同凹腔构型对强化过冷沸腾换热性能的影响机制,发现逆流的三角形翅片凹腔构型比矩形翅片的构型具有更好的过冷沸腾强化换热能力。上述研究结果可为设计更先进的超汽化换热翅片提供参考。

On an established experimental hypervapotron platform with supply of heat flux magnitudes of MW/m^2, the multiphase flow and heat transfer phenomena on local cavities of fins with different configurations ( Rectangle and Triangle), including characteristic vapour bubble behaviors of generation, attachment, departure, coalescence and break-up etc.,were observed and measured comparatively with the planar laser induced fluorescent (PLIF) and high-speed macro-photography techniques. The temperature contours on the slice center plane of fin cavity were measured? The sub cooled boiling performance enhancement mechansms affected by different fin cavity configurations are analyzed. It is concluded that the tringle fin adverse to flow direction has superior sub-cooled boiling performance than rectangular fin. The research results will provide some data reference for future high performance heat exchanger fin shape design.