R32/R134a水平内螺纹管内流动沸腾强化换热实验研究  

Experimental study of convective heat transfer of R32/R134a inside horizontal microfin tubes

作　　者：吴志光[1] 马虎根[1] 蔡祖恢[2] 

机构地区：[1]天津大学热能研究所,天津300072 [2]上海理工大学动力工程学院,上海200093

出　　处：《制冷学报》2003年第1期13-17,共5页Journal of Refrigeration

摘　　要：对非共沸混合制冷剂R32 R134a(2 5 %Wt 75 %Wt)在水平内螺纹强化管中的流动沸腾换热特性进行了研究。实验结果表明 :在内螺纹强化管中的流动沸腾换热性能比在光管中有较明显的提高 ;强化管强化系数变化的大致范围为 1.5～ 2 .2。根据活化穴、二次流和毛细提升三者之间的相互作用 ,探讨了内螺纹强化管的强化机理 ;并从重力影响、非共沸混合工质组分差与二次流影响的角度上 ,对在环状流下混合工质R32 R134a在内螺纹强化管和光管中流动沸腾换热时管子周向壁温的变化特征作出了分析。Experimental study is reported for heat transfer in forced convective boiling of a nonazeotropic mixture of R32/R134a (25%Wt/75%Wt) inside both smooth and microfin tubes with internal spiral grooves. The experimental results show that the microfin tubes have distinct performance advantages over the smooth tube at similar conditions. Considerating the interaction effects among nucleation sites, secondary flow and capillary promotion, this paper describes the enhanced mechanism for the microfin tubes, and the circumferential wall temperature variation of R32/R134a in the annular flow regime was observed and analyzed for both smooth and microfin tubes, which caused by the composition concentration variation, gravity and secondary flow.

关 键 词：R32 R134A 水平内螺纹管 沸腾强化换热 实验研究 非共沸混合制冷剂 环状流 周向壁温 

分 类 号：TB611[一般工业技术—制冷工程] TB64