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Boiling heat transfer of R123 outside single horizontal doubly-enhanced tubes

LIU Qibin;HE Yaling;ZHANG Dingcai;TAO Wenquan   

  • Online:2006-02-25 Published:2006-02-25

R123在水平双侧强化管外池沸腾换热

刘启斌;何雅玲;张定才;陶文铨   

  1. 西安交通大学动力工程多相流国家重点实验室,陕西 西安710049

Abstract: An experimental study on the performance of boiling heat transfer of R123 outside a single horizontal tube was conducted with three doubly-enhanced tubes (No.1,No.2 and No.3)with different geometries at saturation temperatures of 12℃and 10℃ respectively. Tube No.1 was Turbo-B type of Wolverine, and tube No.2,3 also belonged to this type with a minor difference in the tip of the fin. Wilson plot technique was used to separate the boiling heat transfer resistance from the total thermal resistance. It was found that under the same conditions, the in-tube convective heat transfer coefficients of the doubly-enhanced tubes were 2.8—3.1 times of that of the smooth one, and the boiling heat transfer coefficients of R123 were generally lower than those of R22. The thermal resistance analysis reveals that the thermal resistances of the water side and refrigerant side were of the same order for most of the tubes.With the increase in heating water velocity, the thermal resistance of the inner water decreased and that of the refrigerant increased. To further enhance heat transfer, the augmentation of the inner side and the outer side was equally important.

摘要: 对3根双侧高效强化管(管Ⅰ为Turbo-B型管,管Ⅱ、管Ⅲ为改进的Turbo-B型管)在饱和温度为12℃和10℃工况下进行了水平管外R123池沸腾换热的实验研究,采用Wilsan热阻分离法得到制冷剂侧沸腾换热表面传热系数,并对实验结果进行了热阻分析.实验结果表明:在同样条件下,3根强化管的管内对流换热表面传热系数是光管的2.8~3.1倍.在同样的热通量范围内,对于Turbo-B型管,R22池沸腾换热性能的强化效果比R123更明显.随后进行的热阻分析工作,有利于强化换热管的进一步开发.热阻分析表明:在实验范围内,管内外两侧的热阻基本相当,随着管内水流速的增加,管内水侧热阻所占比例降低,管外制冷剂侧热阻所占比例增大.对于沸腾高效强化管的开发,两侧的强化都是应该关注的.