摘要
考察超临界CO2微细管内冷却条件下流动和换热的细观信息(管内不同截面湍动能分布,无量纲速度和温度分布以及湍流雷诺数分布等),结果表明:近壁处湍动能的变化对传热有较大影响,微细管内换热关联式需考虑浮升力的影响。对管径d=0.5,0.3,0.1 mm时,超临界CO2的换热特性进行计算分析,回归出管径小于0.5 mm时,超临界CO2在冷却条件下竖直向上流动和竖直向下流动时的换热关联式,作为对超临界CO2研究的有效补充。
Micro information of flow and heat transfer of supercritical carbon dioxide in miniature cooled tubes were investigated including the turbulent kinetic energy distribution in different sections of cooled tube,the dimensionless temperature and velocity distribution and turbulent Reynolds number distribution. The simulated data indicated that turbulence kinetic energy changement near the wall had a great influence on the heat transfer,buoyancy effects should be considered to heat transfer correlations in miniature tubes. Heat transfer characteristics of supercritical carbon dioxide in different diameter tubes of 0. 5,0. 3,0. 1 mm were calculated and analyzed. Heat transfer correlations in cooled vertical miniature tubes the diameter less than 0. 5 mm were obtained,which could be the efficient supplement for existing studies of heat transfer characteristics of supercritical CO2.
出处
《流体机械》
CSCD
北大核心
2015年第3期17-21,42,共6页
Fluid Machinery
基金
国家自然科学基金项目(51076145)
河南省科技厅科技攻关项目(132102210153)
河南省教育厅科技攻关项目(14A480004)
关键词
超临界CO2
微细管
换热特性
浮升力
supercritical CO2
miniature tube
heat transfer characteristics
buoyancy
