摘要
纵向涡强化传热技术在管翅式换热器中得到了广泛的应用。但是一直以来对纵向涡强化传热的研究主要停留在涡产生器结构参数及布置方式对换热的影响方面,文献对纵向涡强度与换热强度之间定量关系的研究鲜有报道。建立了采用纵向涡强化传热的扁管管翅换热器数值模型,采用二次流强度参数Se分析了翅片及涡产生器结构参数变化时,通道内纵向涡强度与换热强度之间的定量关系;并定量分析了通道中涡产生器引起的纵向涡强度增量与传热强化量之间的定量关系。结果表明:翅片及涡产生器结构参数变化时,Nu、Se与Re之间,以及阻力系数f与Re及Se之间均不存在定量对应关系,但Se与Nu以及?Se与?Nu之间存在对应关系。这表明,在布置有纵向涡产生器的扁管管翅换热器翅侧通道内,纵向涡强度决定了通道内的换热强度。
The longitudinal vortices can potentially enhance heat transfer with small pressure loss penalty. Vortex generators（VGs） which can generate longitudinal vortices are widely used in fin-and-tube heat exchangers for heat transfer enhancement. But for a long time, researches are carried out focusing on the effect of the shape and parameters of VGs on heat transfer and the relationship between the longitudinal vortices intensity and heat transfer intensity is analyzed qualitatively. The quantitative relationship between the longitudinal vortices intensity and heat transfer intensity is seldom reported. Longitudinal vortex is a typical secondary flow, and thus the longitudinal vortex intensity can be defined using the secondary flow intensity parameter. In this paper, the numerical models of flat tube bank fin heat exchanger with VGs mounted on the fin surfaces are studied for different fin and VGs parameters. The longitudinal vortices intensity is quantitatively defined using the nondimensional secondary flow intensity parameter Se. The relationship between the longitudinal vortices intensity and the heat transfer intensity and that between the increment values of Se and Nu caused by the longitudinal vortices are quantitatively studied. The results show that there is no corresponding relationships neither between Nu and Re, nor between Se and Re. Similarly, no linear relationship exists between the friction factor f and the values of Re and Se. But the corresponding relationship exists not only between Se and Nu but also △Se and △Nu. The longitudinal vortices intensity determines the heat transfer intensity in the flat tube fin heat exchanger.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2016年第5期1858-1867,共10页
CIESC Journal
基金
国家自然科学基金项目(51366008,51376086)
甘肃省杰出青年基金项目(145RJDA324)
关键词
涡产生器
纵向涡强度
换热强度
定量关系
传热
数值分析
vortex generator
longitudinal vortices intensity
heat transfer intensity
quantitative relationship
heat transfer
numerical analysis
