管内微-纳多孔镀层强化R245fa垂直上升流动沸腾传热特性  

R245fa vertical upward flow boiling heat transfer characteristics in enhanced tube with micro-nano porous coating

作　　者：曹泷 王光辉 胡春霞 杨卧龙 吴学红 CAO Shuang;WANG Guanghui;HU Chunxia;YANG Wolong;WU Xuehong(College of Energy and Power Engineering,Zhengzhou University of Light Industry,Zhengzhou 450002,Henan,China;Henan International Joint Laboratory of Energy Efficient Conversion and Utilization,Zhengzhou 450002,Henan,China;China Energy Engineering Group Planning&Engineering Co.,Ltd.,Beijing 100120,China)

机构地区：[1]郑州轻工业大学能源与动力工程学院,河南郑州450002 [2]河南省能源高效转化与利用国际联合实验室,河南郑州450002 [3]中国能源建设集团规划设计有限公司,北京100120

出　　处：《化工进展》2024年第12期6615-6625,共11页Chemical Industry and Engineering Progress

基　　金：国家自然科学基金(51906231);河南省中原科技创新领军人才项目(234200510011);河南省重点研发与推广专项(232102321091);郑州轻工业大学青年骨干教师资助计划(13502010008);郑州市协同创新专项(校重大重点项目培育)(2021ZDPY0107)。

摘　　要：面向工业热能高效利用,开展了R245fa垂直上升管内沸腾流动强化传热研究。搭建了可调节角度的R245fa流动沸腾实验台,采用高速摄像机进行流型的可视化分析,并结合实验数据,分析了入口干度、热流密度以及质量流量对管内传热特性的影响。实验工况为:饱和压力0.6MPa,质量流速199.68~701.81kg/(m^(2)·s),热流密度4.99~74.96kW/m^(2),干度0.01~0.9。此外,还对光滑管与微-纳多孔镀层强化管的传热系数和摩擦压降进行了比较。强化管具有明显的强化沸腾换热的效果,其最大强化效果可以达到2.12倍。随着入口干度和热流密度的增大,换热强化因子呈先增加后降低的趋势,综合评价因子的变化趋势与换热强化因子基本一致。流型可视化对比发现,强化管壁面的强润湿性促进壁面液相吸附以及快速再润湿,其相较光滑管而言发生了更早的环状流转变。For the efficient utilization of of industrial waste heat,the R245fa flow boiling heat transfer characteristics was investigated experimentally in a vertically upward tube with a micro-nano porous coating.The effects of inlet vapor qualities,heat fluxes and mass fluxes on the heat transfer characteristics in the tube were analyzed,and the flow patterns were recorded by visualization.Experimental conditions were as follows:saturation pressure 0.6MPa,mass flux 199.68—701.81kg/(m^(2)·s),heat flux 4.99—74.96kW/m^(2),and vapor quality 0.01—0.9.In addition,the heat transfer coefficient and friction pressure drop of the bare tube and enhanced tube were compared.The enhanced tube had an obvious effect of enhancing boiling heat transfer,and the maximum heat transfer enhancement factor could reach 2.12 times.With the increasing inlet vapor qualities and heat flux,the heat transfer enhancement factor showed a trend of initially increasing and then decreasing.The variation trend of the performance evaluation parameter aligned closely with that of EF.The visualization showed that the strong wettability of the enhanced tube accelerated the diffusion of R245fa liquid on the tube wall surface and facilitated rapid rewetting.In comparison to the bare tube,the transition to annular flow occurred earlier in the enhanced tube.

关 键 词：R245FA 强化管 垂直向上 流型 传热特性 

分 类 号：TK172[动力工程及工程热物理—热能工程]