低温重力热管传热性能的理论与实验研究  

Theoretical and experimental investigation on heat transfer characteristics in a cryogenic two-phase closed thermosyphon

作　　者：焦波[1] 邱利民[1] 张洋[1] 

机构地区：[1]浙江大学制冷与低温研究所,浙江杭州310027

出　　处：《浙江大学学报（工学版）》2008年第11期1966-1972,共7页Journal of Zhejiang University：Engineering Science

基　　金：浙江省科技计划资助项目(2006C24G2010027)

摘　　要：为给重力热管在低温区的应用提供理论依据,以液氮作为工质对其稳态传热特性进行了实验研究.分别对冷凝段、蒸发段液膜和液池进行分析,建立了综合的数学模型.根据质量和能量守恒方程迭代计算得到了液池高度和液膜沿管长的分布.在液池模型中,通过假设空泡系数的分布,基于其他实验研究的结论提出了自然对流与核态沸腾换热面积公式.当工质液体体积与重力热管总体积的比值为13.5%和15.2%时,计算值与实验值吻合较好.理论和实验研究结果均表明,在蒸发段内液膜和液池的位置对蒸发段壁温的分布有较大的影响.In order cryogenic applicatio teristics in a TPCT to provide theoretical foundation for the two phase closed thermosyphon （TPCT） in ns, experimental investigation was performed on the steady-state heat transfer eharacwith liquid nitrogen as working fluid. A comprehensive model was developed based on the analyses on condenser, liquid film section and liquid pool section in evaporator, respectively. The liq uid pool height and the distribution of liquid film along the tube were determined by iteratively solving the mass and energy conservation equations. In the liquid pool model, by assumption on the distribution of void fraction, new correlations of effective areas of natural convection and nuclear boiling were proposed based on the experimental results from other study. Comparison showed that the calculation and experimental results agreed well with each other when the volume ratio of charged liquid to the whole TPCT was 13.5% and 15.2%. Both theoretical and experimental results show that the wall temperature is affected greatly by the distribution of liquid film and liquid pool in evaporator.

关 键 词：重力热管 低温传热 气液两相流 数值模拟 

分 类 号：TK124[动力工程及工程热物理—工程热物理]