自然循环加热段内摩擦阻力及对流传热的实验研究  

INVESTIGATION ON FRICTION AND HEAT TRANSFER IN A TUBE WITH NATURAL CIRCULATION

作　　者：杨瑞昌[1] 刘若雷[1] 刘京宫[1] 刘涛[1] 

机构地区：[1]清华大学热能工程系,热科学与动力工程教育部重点实验室,北京100084

出　　处：《工程热物理学报》2008年第1期108-111,共4页Journal of Engineering Thermophysics

基　　金：国家自然科学基金(No．50476012);空泡物理和自然循环重点实验室2006基金

摘　　要：以常压去离子水为工质,对自然循环工况下上升加热段内单相水的摩擦阻力及对流传热特性进行了实验研究。结果表明,自然循环工况下加热段内由浮升力引起的自由流动对摩擦阻力及对流传热特性有重要影响,自然循环与强制循环二种工况下加热段内的摩阻系数及对流换热系数存在明显差别;并且,自然循环工况下加热段内的摩擦阻力存在滞后现象。通过实验提出了计算自然循环工况下加热段内单相水的摩阻系数及对流换热系数的经验关系式。The friction and convective heat transfer of single phase water flow in a vertical heated tube at natural circulation condition were experimentally investigated. The experimental results indicate that free convection caused by buoyancy in the heated tube has great influence on the friction and convective heat transfer under natural circulation condition. The friction factors and convective heat transfer coefficients in the tube obtained from the experiments carried out respectively at natural circulation and forced flow conditions were quite different. Besides, it is found that the friction in the tube at natural circulation was also affected by the method of heat import to the tube. Based on the experimental results, the empirical correlations for the calculation of friction and convective heat transfer in the tube at natural circulation condition have been presented.

关 键 词：自然循环 摩擦阻力 对流传热 实验研究 

分 类 号：TK124[动力工程及工程热物理—工程热物理]