低温冷凝可视化实验装置设计

Design of visual cryogenic condensation experimental device

低温流体与常规室温流体冷凝存在显著差异,简述了国内外报道的主要低温冷凝实验装置,指出要准确描述翅片通道内冷凝及两相流动过程,必须借助先进的可视化手段。为解决空分装置中主冷凝蒸发换热器翅片通道内低温流体冷凝热阻大、换热效率低的难题,设计搭建了一套低温冷凝可视化实验装置,实验段采用带光窗的可拆密封设计,便于研究平壁表面及各种型号翅片通道内冷凝换热过程。经初步测试,该实验装置运行稳定,借助高速摄像机可清楚地观察到氮冷凝两相流动的现象。

There are many crucial distinctions between cryogenic condensation and room temperature condensation. This paper provides a worldwide overview of the main experimental devices for cryogenic condensation,and further demonstrates that advanced visualization tools are needed in order to accurately describe the process of condensation and two-phase flow in plate-fin channels. Aimed at lowering thermal resistance and enhancing heat exchange efficiency for the main condenser-evaporator in air separation unit,a set of visualized experimental device for cryogenic condensation was designed and established. The experimental section was designed of a detachable window pervious to light and vacuum sealed,which was a remarkable convenience to study the condensation on flat wall surface or in various types of plate-fin channels.The experimental device runs steadily on preliminary tests. The two-phase flow phenomenon of nitrogen during condensation process can be clearly observed through a high speed camera. This detailed visualization study can serve as a fundamental research for the heat transfer mechanism and heat exchange enhancement of cryogenic condensation.