基于垂直环管内旋流对流动边界层的扰动机理，采用数值模拟的方法研究了叶片角度、雷诺数以及进口水温对管内换热以及流动特性的影响，揭示了重力对环管内旋流流动的内在影响机制。结果表明：与水平环管相比，垂直环管的综合换热性能变化平缓，主要受到重力对压降的影响；与雷诺数相比，叶片角度对流场以及温度场的影响最显著；在雷诺数小于15 000，叶片角度为30°时管内的换热性能最佳。

Based on the disturbance mechanism of swirling flow on boundary flow region in vertical annular tubes, the effects of different vane angles, Reynolds numbers and inlet water temperature on heat transfer and flow characteristics in tubes were studied by numerical simulation method. The internal influence mechanism of gravity on swirling flow in annular tube was revealed. The results show that the comprehensive heat transfer performance of vertical annular tube changes gently compared with horizontal annular tube, mainly affected by the influence of gravity on pressure drop;the vane angles have the most significant effects on flow and temperature fields compared with the Reynolds numbers; when the Reynolds number is less than 15 000 and the vane angle is 30°, the heat transfer performance in tubes is the best.

TK221

广东省自然科学基金（2019A1515010460）；广东省分布式能源系统重点实验室资助项目（2020B1212060075）