摘要
本文对超临界压力下正癸烷在内径为0.95 mm和2 mm竖直微细圆管内对流换热进行了实验研究.入口压力p_(in)=3 MPa和入口雷诺数Re_(in)=4000时,分析了管径、变物性、浮升力和加速对对流换热的影响.结果表明:在所研究的工况范围内,对于0.95 mm内径圆管,浮升力和加速对换热的影响可忽略,对流换热主要受变物性的影响;而对于2mm内径圆管,在高热流密度时,浮升力对正癸烷的对流换热影响很大,向上流动时引起换热恶化,向下流动时引起换热强化,加速对流动换热的影响可忽略.
This paper presents experimental investigations of the convection heat transfer of supercritical pressure n-decane in a vertical tube with inner diameters of 0.95 mm and 2 mm to investigate the effects of the tube inner diameters, the variations of thermophysical properties, buoyancy and flow acceleration on convective heat transfer at the inlet pressure of 3 MPa and the inlet Reynolds number of 4000. The experimental results indicate that for the inner diameter 0.95 mm tube, the convective of heat transfer of supercritical pressure n-decane is mainly influenced by the variations of thermophysical properties and the effects of buoyancy and flow acceleration can be neglected, for the inner diameter 2 mm tube, the heat transfer is impaired for the upward flow and enhanced for the downward flow due to the effect of buoyancy at higher heat fluxes and the effect of flow acceleration can be neglected.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2014年第1期114-118,共5页
Journal of Engineering Thermophysics
基金
国家自然科学基金重点项目(No.50736003)
关键词
超临界压力
正癸烷
浮升力
对流换热
supercritical pressure
n-decane
buoyancy
convection heat transfer
