空气在立式花瓣管外螺旋流动传热与流阻性能研究

试验研究了空气在5种管径相同、不同翅片高度和翅片间距的立式花瓣管外螺旋流动的传热和流阻性能,分析出在试验范围内:花瓣管翅片高度相同时存在一最适宜翅片间距,使其传热性能最优;花瓣管翅片间距相同,翅片越高,其传热性能越好,而流动阻力损失也越大;管外系统压力越高,换热效果越好,且不会增加其流动阻力,这可为设计高效立式螺旋隔板花瓣管换热器提供参考依据。

Heat Transfer and Flow Resistance Performance of Air Helical Flow Outside Upright Petal-Shaped Tubes

The heat transfer performance and flow resistance of air were investigated with air flowing heli-cally outside five experimental petal-shaped tubes with the same diameter,but different in fin height and spacing.In the experimental range,results show that there is a suitable fin spacing to make the heat transfer characteristic best for the petal-shape tube with the same fin height.With the same fin spacing,when fin height is increased,the heat transfer characteristic is better and the flow resistance loss is big-ger.The higher system pressure outside tube is of the better heat transfer effect without increasing the flow resistance.The results provide reference to the design of the high-efficient upright helical-baffle heat-exchanger with petal-shaped tubes.