Liquid exploding emission during boiling nucleation in capillary tubes  

作　　者：WU Di PENG XiaoFeng 

机构地区：[1]Laboratory of Phasechange and Interfacial Transport Phenomena, Department of Thermal Engineering, Tsinghua University, Beijing 100084,China

出　　处：《Chinese Science Bulletin》2010年第20期2186-2195,共10页

基　　金：supported by the National Natural Science Foundation of China(50636030);the Specialized Research Fund for the Doctoral Program of Higher Education(200800030008)

摘　　要：A series of experiments was conducted to visually observe boiling nucleation phenomena in micro capillary tubes employing a high speed CCD.At a higher heat flux the liquid in capillary tubes was emitted instantaneously rather than generating nucleate boiling,which is referred as liquid exploding emission in this paper.Both critical emission heat flux and temperature corresponding to this phenomenon were measured for tubes with different heating lengths and arrangements of two end sections.Boiling nucleation and liquid film evaporation played critical roles in different stages during exploding emission.Dimensionless critical emission volumetric heat was introduced to describe the conditions of the emission instead of heat flux,and theoretical discussions were conducted to explore the influences of thermal properties and geometrical configuration,particularly heating length and asymmetry of two end sections of tubes.A series of experiments was conducted to visually observe boiling nucleation phenomena in micro capillary tubes employing a high speed CCD. At a higher heat flux the liquid in capillary tubes was emitted instantaneously rather than generating nucleate boiling, which is referred as liquid exploding emission in this paper. Both critical emission heat flux and temperature correspond- ing to this phenomenon were measured for tubes with different heating lengths and arrangements of two end sections. Boiling nucleation and liquid film evaporation played critical roles in different stages during exploding emission. Dimensionless critical emission volumetric heat was introduced to describe the conditions of the emission instead of heat flux, and theoretical discussions were conducted to explore the influences of thermal properties and geometrical configuration, particularly heating length and asymmetry of two end sections of tubes.

关 键 词：爆炸过程 微毛细管 热排放 核沸腾 液体 高热通量 高速CCD 成核现象 

分 类 号：O551.3[理学—热学与物质分子运动论]