摘 要：利用三维数值模拟的方法对带有3种异形纵向涡发生器的H型翅片椭圆管换热器的空气侧流动传热特性进行研究。基于H型翅片椭圆管束，讨论了在不同雷诺数下，纵向涡发生器的摆放位置、摆放攻角和形状对空气侧流动传热的影响。研究表明：纵向涡发生器能够将高能量的流体引向流速较低的壁面区域，使冷热流体之间的混合加剧，增强流体的湍流动能，进而达到强化传热的效果；与无纵向涡发生器的管束相比，带纵向涡发生器管束的传热效果有明显的提高；当纵向涡发生器后置时，换热器的传热效果最优；在雷诺数相同，攻角为30°时，流体的传热性能和阻力特性均达到最优；相同攻角摆放时，椭圆角矩形发生器的传热性能和阻力因子均优于其他两种形式的发生器。研究结果为烟气余热回收系统换热器传热性能强化提供理论依据。

Abstract:The air-side flow and heat transfer characteristics of H-type fined oval tube heat exchangers with three kinds of longitudinal vortex generators were studied by numerical simulation.Based on the H-type fined oval tube banks,the influences of the position,angle of attack and shape of vortex generators on the air side flow and heat transfer are discussed under different Reynolds numbers.The results show that the vertical vortex generator can lead the high energy flow to the wall area with low flow velocity,resulting in increased mixing between the hot and cold fluids,higher turbulent kinetic energy,and n turn,enhanced heat transfer.The heat transfer effect of the tube with longitudinal vortex generator is evidently improved.When the vertical vortex generator is placed behind the oval tubes,the heat exchanger heat transfer effect is optimal.At a same Reynolds number,the heat transfer effect and the resistance characteristic of the fluid are optimized when the angle of attack is 30°.With a same angle of attack,the heat transfer performance and resistance characteristics of the elliptical angle generator are better than others.These results are expected to provide a theoretical basis for the heat transfer enhancement of heat exchanger in the flue gas waste heat recovery system.

TK172