竖直圆管内超临界压力煤油传热特性实验研究  

Experimental Investigation on Heat Transfer of Kerosene Flowing in a Vertical Tube at Supercritical Pressure

作　　者：胡江玉 周进[1] 潘余[1] 王辉[1] 王宁[1] 任春雷[1] 

机构地区：[1]国防科学技术大学航天科学与工程学院,湖南长沙410073

出　　处：《气体物理》2016年第4期51-57,共7页Physics of Gases

基　　金：国家自然科学基金(11372348)

摘　　要：在压力2.5~4 MPa,质量流量0.7~1.7 g/s,热流密度0.06~1 MW/m^2的实验条件下,对煤油在内径1mm,长度300 mm竖直上升圆管内的流动与传热特性开展了实验研究,并分析了传热系数随局部油温的变化及不同实验参数对传热的影响.结果表明,超临界压力下煤油传热主要由自身物性和流动状态决定.超临界压力煤油传热过程大致可以分为3个区域:正常传热区传热强化区和传热恶化区.传热强化主要是湍流掺混增强和近壁面流体在拟临界温度附近物性剧烈变化的综合作用;传热恶化则是因为壁温及近壁面流体温度远高于拟临界温度,在近壁面发生了类似于亚临界状态下的"拟膜态沸腾".The flow and heat transfer characteristics of kerosene flowing in a vertical upward circular tube were experimentallyinvestigated. The tube is 1 mm in diameter and 300 mm in length. Pressure ranges from 2.5 ？4 MPa, mass flow rateranges from 0.7 -1.7 g/s, and heat flux ranges from 0.06 -1 MW/m2. Analysis was done to find out how the heat transfercoefficient changes with the local fluid temperature. Influence of different experimental parameters on heat transfer was alsoconcluded. Results indicate that heat transfer of kerosene under supercritical pressure is mainly determined by its physicalproperties and the flow state. The heat transfer characteristics of kerosene under supercritical pressures could be divided intothree regimes, namely the common heat transfer regime, the enhanced heat transfer regime and the deteriorated heattransfer regime. Heat transfer enhancement is due to the combination of turbulent mixing and the drastic change of propertiesof kerosene near pseudo-critical temperature in the near wall zone while heat transfer deterioration is caused by the“pseudo-film boling” of the high temperature fluid in the near wall region.

关 键 词：流动状态 物性变化 传热恶化 传热强化 

分 类 号：O354.7[理学—流体力学]