R1234ze(E)与R134a在水平双侧强化管外的凝结换热对比实验  

Experimental Comparison on Condensation Heat Transfer of R1234ze(E)and R134a on Horizontal Double-sided Strengthened Tube

作　　者：孙晨 欧阳新萍[1] 夏荣鑫 SUN Chen;OUYANG Xin-ping;XIA Rong-xin(Institute of Refrigeration and Cryogenics,University of Shanghai for Science and Techonology,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

出　　处：《热能动力工程》2021年第8期72-77,共6页Journal of Engineering for Thermal Energy and Power

摘　　要：搭建了水平单管降膜蒸发试验台,以第四代制冷剂R1234ze(E)和第三代制冷剂R134a作为工质,在新型水平双侧强化管管外分别进行了改变管内水速、热流密度和冷凝温度条件的凝结换热实验。使用Wilson-Gnielinski图解法计算得到管内表面传热系数hi,进一步采用热阻分离法分离出两种制冷剂的管外表面传热系数,并分析了管内冷却水水速、冷凝温度和壁面过冷度的变化对其换热性能的影响。实验结果表明:同根实验管下不同制冷剂凝结换热性能的差异与制冷剂物性与强化管结构之间的匹配特性有关,实验管型下,R1234ze(E)的管外凝结换热性能高于R134a。A horizontal single-tube falling film evaporation test stand was built.Using the fourth-generation refrigerant R1234 ze(E)and the third-generation refrigerant R134 a as the working fluid,and the condensation heat transfer experiments were carried out outside the new type horizontal double-sided strengthened tube.The experiments were carried out under different conditions of water velocity,heat flux density and condensation temperature.The Wilson-Gnielinski graphical method is used to calculate the surface heat transfer coefficient hi inside the tube,and the thermal resistance separation method is used to separate the surface heat transfer coefficient of the two refrigerants outside the tube.The effects of changes in the cooling water velocity,condensation temperature and wall subcooling degree on the heat transfer performance of the tube are analyzed.The experimental results show that the difference in surface heat transfer performance of different refrigerants under the same experimental tube is related to the matching properties of refrigerant physical properties and strengthened tube structure.In this experimental tube type,the condensation heat transfer performance of R1234 ze(E)is higher than that R134 a outside the tube.

关 键 词：凝结换热 R1234ze(E) 强化管结构 换热关联式 强化换热 

分 类 号：TB657.5[一般工业技术—制冷工程] TB611