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对制冷剂R134a在水平强化换热管管内的凝结换热性能进行了实验研究。实验管为两种内微翅管,分别命名为A管和B管。实验件采用套管结构,强化内管外表面和外管内表面之间(管间)走乙二醇水溶液。实验过程中管内冷凝温度为51℃,管间乙二醇水溶液的流速为3.35 m/s,乙二醇水溶液的进口温度根据制冷剂的质量流速做相应调整,以保证试件出口制冷剂有一定的过冷度。实验结果表明:两种水平强化管的管内冷凝换热系数均随着制冷剂质量流速的增加而增大,在制冷剂质量流速从300 kg/(m2.s)增加到700kg/(m2.s)时,A管的管内冷凝换热系数比B管高1.87%到6.28%,而B管的制冷剂流动阻力比A管高9.56%到11.05%,A管的结构优于B管。
The experimental study on the condensation heat transfer performance of refrigerant R134a in a horizontal heat exchanger tube was carried out. Experimental tube for two kinds of finned tube, respectively, named A tube and B tube. The test piece adopts the casing structure to strengthen the ethylene glycol aqueous solution between the outer surface of the inner tube and the inner surface of the outer tube (between the tubes). During the experiment, the condensation temperature in the pipe was 51 ℃, the flow rate of the ethylene glycol aqueous solution in the pipe was 3.35 m / s. The inlet temperature of ethylene glycol aqueous solution was adjusted according to the mass flow rate of the refrigerant to ensure that there was a certain amount of refrigerant The degree of undercooling. The experimental results show that the tube heat transfer coefficients increase with the increasing of the mass flow rate of the refrigerant in the two horizontal tubes. When the mass flow rate of the refrigerant increases from 300 kg / (m2.s) to 700 kg / (m2.s) ), The heat transfer coefficient of tube A was 1.87% to 6.28% higher than that of tube B, while the flow resistance of tube B was 9.56% to 11.05% higher than that of tube A. The structure of tube A was better than that of tube B.