两种平直内翅管流动与换热实验研究

Experimental Study on the Pressure Drop and Heat Transfer of Two Different Tubes With Plain-Rectangle Internal Fins

在恒热流边界条件下,以空气为介质,对中心被堵平直内翅片管的两种结构(?)翅片开孔和翅片不开孔,进行了流动与传热特性实验研究,获得了听测范围内的充分发展段的换热及阻力的实验关联式。采用相同质量流量、相同泵功及相同压降三个准则对所测内翅片管的综合性能进行了评价,结果表明,在相同几何参数下,翅片开孔结构的内翅管与不开孔结构的内翅管相比,其综合换热性能得到明显提升。

Pressure drop and heat transfer characteristics of air in two tubes with internal longitu- dinal plain fins were investigated experimentally at constant wall heat flux. The tested tube has a double-pipe structure, with the inner blocked tube as an insertion. Two different fins, plain-rectangle fin and perforated plain-rectangle fin, are in the annulus and stretch its full width in a wavy manner. The friction factor and Nusselt number correlations in the fully developed region were obtained within the Reynolds number range from 400 to 4000. The comprehensive heat transfer characteristics of the tested tubes were evaluated using three criteria： identical mass flow, identical pumping power and identical pressure drop. The results show that perforated internal longitudinal finned tube provides more excellent comprehensive thermal performance than the other at the same geometrical parameter.