横向节距对锯齿螺旋翅片换热管特性影响的实验研究

Experimental Studies on the Effects of Transverse Pitch on Heat Transfer and Flow Resistance Characteristics of Serrated Spiral Finned Tube Banks

为获得管束布置结构对锯齿螺旋翅片换热管特性的影响,在分析其影响机制的基础上对9个锯齿螺旋翅片管错列管束进行了实验研究,获得了横向节距对锯齿螺旋翅片管束换热与阻力特性的影响规律,并提出相应的关联式。结果表明:在横向相对节距范围2.31～3.15,相同雷诺数Re和纵向节距下随横向节距增大,翅侧努谢尔数Nu变化在±3%内;欧拉数Eu减小约20%;综合传热性能j/f(科尔伯恩传热因子与范宁摩擦因子比值)增大约25%。通过与错列光管管束的比较,表明锯齿螺旋翅片管束强化换热性能较优,在大型气体换热设备中具有广泛的应用前景。

In the interest of the effects of tube layout structures on heat transfer and flow resistance characteristics of serrated spiral finned tube banks （SSFTB）, nine SSFTB with staggered layouts in terms of various transverse pitch and longitudinal pitch of tube banks were tested after an analysis of its influencing mechanism. Accordingly, the effects of transverse pitch on heat transfer and flow resistance characteristics of SSFTB were performed, and the calculating correlations of heat transfer and flow resistance of SSFTB were put forward. The results from experimental studies are： in the range of relative transverse pitch of tested tube banks 2.31-3.15, with the increasing of transverse pitch the Nu number change slightly （〈3%） and the Eu number evidently decrease about 20%, meanwhile the comprehensive heat transfer performance index j/f （ratio of Colburn heat transfer factor and Fanning friction factor） increase about 25% in the same Re number and longitudinal pitch. The comparisons of bare tube banks and staggered layouts indicate that SSFTB have outstanding performances of heat transfer enhancement, so it must have widely applied prospects in large-scale heat-exchange facility.