Abstract:

Internal inserts can effectively enhance heat transfer，and also have good anti-scaling and scale removing performance.In the present numerical study，the effects of structural parameters of the spiral rotor internal insert on heat transfer and flow resistance were investigated.The numerical results confirmed that the heat transfer is enhanced by 30% and the friction resistance is increased by 600%～700% as compared with those in plain tube respectively.The increase in the clearance between blade and tube wall，the increase in the helix pitch of rotor，and the decrease in the radius of rotating shaft can decrease the rotational speed and then decrease the heat transfer rate and friction factor.Appropriately increasing the helix pitch of rotor，reducing the clearance between blade and tube wall and reducing the radius of rotating shaft can lead to a better heat transfer performance.

Key words:

螺旋转子, 强化换热, 阻力特性, 数值研究

摘要：

管内插入物是一种强化管内换热的有效方法，内插可以旋转的结构在强化换热的同时还具有良好的除垢效果。数值研究了内插螺旋转子的管内流动与换热，发现与光管相比，换热强化30%，而阻力则为光管的6～7倍。数值计算结果表明，叶片与管壁间隙、转子螺旋节距的增加以及转轴半径的减小，可引起转子转速不同程度的减小，从而导致管内Nusselt数和阻力系数的减小。适当增加转子螺旋节距，减小转轴半径及叶片与管壁间隙，可使其强化换热性能更优。

关键词:

螺旋转子, 强化换热, 阻力特性, 数值研究