叶片旋流管内核心流强化传热分析与结构优化

管内湍流强化传热方法一般是增加壁面换热面积，但这会显著提高管内流动阻力。本文根据管内核心流强化传热的原理，提出了一种高效低阻的叶片旋流管，分析其传热强化的机理，建立相应的物理和数学模型。数值分析的结果表明，在圆管内置若干组旋流叶片后，可显著强化管内湍流换热，且流动阻力的增幅低于换热强化的增幅；当常温水流过管长为960 mm，管径为20 mm的圆管，且在管内核心流区域设置4组4叶片旋流单元时，其性能评价系数SPEC在Re数为3 000~15 000的范围内均超过1.5，最高可达1.9左右。

Analysis on Heat Transfer Enhancement in the Core Flow of a Tube Filled With Swirling Flow Vanes and Its Structure Optimization

The conventional method of heat transfer enhancement for turbulent flow in tube is to increase the heat transfer area, but it will increase the pressure drop across the tube significantly. Based on the theory of heat transfer enhancement in the core flow in this article, a kind of vane-swirling flow tube with relatively higher heat transfer efficiency and lower flow resistance was presented in this paper, and accordingly the physical and mathematical models for the vane-swirling flow tube were established. Numerical simulation results show that significant effect of heat transfer enhancement for turbulent flow appears in the tube filled with certain amount of swirling flow units, while the increase amplitude of pressure drop is lower than that of enhanced heat transfer. When Re number is in the scope of 3 000~15 000, and water with normal temperature flows through the tube filled with 4 groups of 4-blade swirling flow units, the performance evaluation criteria numbers SPEC are higher than 1.5, and the maximum SPEC is around 1.9.