The shell side heat transport enhancement characteristics of double tube heat exchangers composed of twisted oval tubes alone and twisted oval tubes coupled with circular tubes is investigated numerically in the range of Reynolds number from 2700 to 22,000. The effects of the aspect ratio, twist pitch length, twisting direction and ratio of inner tube diameter to outer tube diameter on shell side convection heat transfer and hydraulic resistance performance are also explored. The rotational motions caused by the twisted oval tubes realize the occurrence of secondary flow and spiral flow which destroys the boundary layer and intensifies the shell side heat transport of double tube heat exchangers composed of twisted oval tubes. Simultaneously reducing the twist pitch length and increasing the inner tube aspect ratio can significantly improve the shell side comprehensive heat transport performance. Case 10 with the largest inner tube aspect ratio and the smallest twist pitch length shows the highest comprehensive heat transport performance. The comprehensive heat transport performance can be increased by 24.0– 39.0% by the application of twisted oval tubes as inner tubes. The leftward and rightward twisting directions of inner twisted oval tubes have the same effect on the shell side heat transport intensification.

在雷诺数范围为2700至22,000的范围内，对仅由扭曲的椭圆形管和扭曲的椭圆形管与圆形管组成的双管式换热器的壳侧传热特性进行了数值研究。还研究了纵横比，扭曲节距长度，扭曲方向以及内管直径与外管直径之比对壳侧对流换热和水力阻力性能的影响。由扭曲的椭圆形管引起的旋转运动实现了二次流和螺旋流的出现，这破坏了边界层并增强了由扭曲的椭圆形管组成的双管热交换器的壳侧热传递。同时减小扭曲节距长度和增加内管的长宽比可以显着提高壳侧的综合传热性能。具有最大内管纵横比和最小扭曲节距长度的案例10显示出最高的综合传热性能。通过使用扭曲的椭圆形管作为内管，可以将综合传热性能提高24.0％至39.0％。内扭曲的椭圆形管的向左和向右扭曲方向对壳侧传热强化具有相同的作用。通过使用扭曲的椭圆形管作为内管，可以将综合传热性能提高24.0％至39.0％。内扭曲的椭圆形管的向左和向右扭曲方向对壳侧传热强化具有相同的作用。通过使用扭曲的椭圆形管作为内管，可以将综合传热性能提高24.0％至39.0％。内扭曲的椭圆形管的向左和向右扭曲方向对壳侧传热强化具有相同的作用。