R22在水平双侧强化管外池沸腾换热  

Boiling heat transfer of R22 outside single horizontal doubly-enhanced tubes

作　　者：刘启斌[1] 何雅玲[1] 张定才[1] 陶文铨[1] 

机构地区：[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

出　　处：《化学工程》2008年第4期12-16,共5页Chemical Engineering(China)

基　　金：国家重点基础研究发展计划973项目(2007CB206902);教育部科学技术研究重大项目(306014)

摘　　要：对2根双侧高效强化管(管I,管II)在饱和温度为9.6℃和5.8℃工况下进行了水平管外R22池沸腾换热实验研究,采用Wilson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,2根强化管的管内对流换热表面传热系数是光管的2.2—2.8倍。在饱和温度为9.6℃时,管II的管外沸腾换热表面传热系数达到(2.2—3.4)×104W/(m2.K),高出光管一个量级。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。An experimental study on the performance of boiling heat transfer of R22 outside horizontal tube was conducted with two doubly-enhanced tubes （Tube Ⅰ and Tube Ⅱ） with different geometries at saturation temperatures of 9.6 ℃ and 5.8 ℃, respectively. Wilson plot technique was used to separate the boiling heat transfer resistance from the total thermal resistance. Under the same conditions, the in-tube convective heat transfer coefficient of the doubly-enhanced tubes is 2.2-2.8 times that of the smooth one, and at the saturation temperature of 9.6 ℃, the boiling heat transfer coefficient of Tube II can reach （2.2-3.4） × 10^4 W/（ m^2 · K）, which is one order of magnitude larger than that of the smooth one. The thermal resistance analysis reveals that the thermal resistances of the water side and refrigerant side are of the same order for the two tubes. With the increase of heating water velocity, the thermal resistance of the inner water decreases and that of the refrigerant increases. To further improve the heat transfer coefficient, the enhancement for both inside and the outside is equally important.

关 键 词：双侧强化管 沸腾 传热特性 

分 类 号：TK124[动力工程及工程热物理—工程热物理]