微细圆管内CO2两相沸腾换热实验研究  

Investigation on Two-phase Boiling Heat Transfer of CO2 in Micro-circular Tube

作　　者：姜林林[1] 柳建华[1] 张良[1] 徐小进[2] JIANG Lin-lin;LIU Jian-hua;ZHANG Liang;XU Xiao-jin(Refrigeration Technology Institute,University of Shanghai for Science and Technology,Shanghai,China,Post Code ： 200093;NO.704 Research Institute,CSIC,Shanghai,China,Post Code ： 200093)

机构地区：[1]上海理工大学制冷技术研究所,上海200093 [2]中国船舶重工集团公司第七O四研究所,上海200093

出　　处：《热能动力工程》2018年第9期14-22,共9页Journal of Engineering for Thermal Energy and Power

基　　金：上海市部分地方院校能力建设专项计划(16060502600)~~

摘　　要：本文对CO2在水平微细管内流动沸腾特性进行实验研究。实验结果表明：热流密度增加对强化核态沸腾换热和高干度区域流型转变具有显著影响,随着热流密度的增加换热系数增加,对摩擦压降影响很小;质量流率对于换热系数的影响较小,但随着质量流率的增加摩擦压降大幅增加,质量流率的大小直接决定了换热过程所经历流态;饱和温度升高换热系数相应升高,摩擦压降减小,且对流态转变特性有重要影响。在同样工况下摩擦压降最大值先于换热系数最大值出现,理论分析采用的流态形式与实际CO2管内流动流动沸腾换热流态基本一致。The boiling characteristics of CO2 flow in horizontal micro-tube were studied in this paper. Ex- perimental results show that with the increase of heat flux, nucleate boiling heat transfer as well as heat transfer coefficient is significantly enhanced, and the frictional pressure drop is little affected, while the flow pattern transfer is remarkably impacted in the high vapor quality area. the effect of mass flow rate on heat transfer coefficient is small, but its influence on the frictional pressure drop is strong. The mass flow rate directly determines the flow patterns in the heat transfer process. With the increase of saturation tem- perature the heat transfer coefficient increases and the frictional pressure drop decreases, and the satura- tion temperature is critical to the transfer characteristic of flow patterns. Under the same operating condi- tions, the max frictional pressure drop occurs before the maximum heat transfer coefficient. The flow pat- tern identified from the theoretical analysis is essentially consistent with that of the actual boiling flow present in the micro tube of CO2.

关 键 词：二氧化碳 换热系数 摩擦压降 流态 

分 类 号：TK124[动力工程及工程热物理—工程热物理]