三种大管径翅管式换热器传热与阻力特性的试验研究

为考察不同翅片形式以及管排数对空气侧强化传热的影响，分别对9排和12排带平直、开缝、纵向涡3种翅片形式共6个翅片管换热器元件空气侧的传热及阻力性能进行了试验研究，发现开缝翅片管换热器的传热性能高于带纵向涡翅片管换热器和平直翅片管换热器，但阻力相应也增加，带纵向涡发生器的翅片传热性能略低于开缝翅片，但阻力却只比平直翅片稍大，这表明采用这种翅片形式可获得较好的综合性能．不同管排数的同一片型换热器的努塞尔数及阻力因子相差很小，可以认为与管排数无关．在试验的雷诺数范围内针对各个试件整理出了传热和阻力的经验关联式，可为相关的理论研究和工程应用提供参考．

Experimental Investigation on Heat Transfer and Flow Friction Characteristics in Three Types of Plate Fin-and-Tube Heat Exchangers

Air side heat transfer and friction characteristics in three nine-row and three twelve- row fin-and-tube heat exchanger cores with varied types of fin configurations are experimentally investigated.The test cores consist of three extended surfaces such as plain fins(PF),slit fins (SF)and fins with longitudinal vortex generator(LVG).It is shown that SF offers higher heat transfer and flow friction than the other two fin surfaces.The heat transfer of LVG is slightly lower than that of SF while the corresponding flow friction is slightly larger than that of PF,and LVG in heat exchanger enables to perform better.The effects of number of tube rows on the same kind of fin surface are ignorable.The heat transfer and friction factor correlations for three fin surfaces are obtained in a wide range of Reynolds numbers for the further research and engi- neering applications.