竖直螺旋槽管壁面液膜在蒸发/冷凝时的传热特性的研究

研究竖直螺旋槽管壁面液膜在传热条件下的液膜形成及流动特性,建立了单组分流体的物理和数学模型并得出解析解,且分析了壁面液膜在蒸发,冷凝及无热传输时的液膜厚度分布及速度分布,结果表明,液膜的形状主要受表面张力影响,在表面内弯处流膜较厚,而在槽道起始部液膜较薄,相对于光滑直管,竖直螺旋槽管壁面液膜具有均匀的厚度分布和更好的传热传质性质,特别在冷凝时壁面液膜更薄且分布更加均匀。

Heat Transfer of the Liquid Falling Film on the Surface of a Vertical Helix Tube

The purpose of this study is to investigate the formation of a liquid falling film and its flow behavior on the surface of a vertical helix tube. The physical and mathematical model for single ingredient fluid are established and the effects of the surface geometry of the vertical helix tube on the liquid film flow were studied. The results show that the formation of liquid film is mainly affected by surface tension of the liquid and the surface geometry of the helix tube. The film thickness goes up at the trough and becomes thinner at the crest. The film thickness on the vertical helix tube is more uniform and has better heat and mass transfer performance than the classical unfluted tube.