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对水蒸气在垂直钛板表面的冷凝传热特性进行了可视化实验研究。实验结果表明,蒸汽在钛表面为液滴和沟流状液膜共存的混合冷凝形式。随着表面过冷度的增大,滴状区所占的面积比η逐渐减小,且液滴的脱落直径逐渐增大,导致表面的冷凝传热系数随之下降。η值大于50%时,冷凝传热系数随滴状区所占面积比的减小而陡降,滴状区面积小于膜状区后,η值对冷凝表面传热性能的影响较小。
The experimental study on the condensation heat transfer characteristics of water vapor on the surface of vertical titanium plate was carried out. The experimental results show that the steam is mixed and condensed on the titanium surface by the coexistence of liquid droplets and channel liquid film. As the supercooling degree increases, the area ratio η of the drop zone decreases and the diameter of droplet increases gradually, which leads to the decrease of the surface condensation heat transfer coefficient. When the value of η is more than 50%, the condensation heat transfer coefficient drops sharply with the decrease of the area ratio of drop zone. The smaller the drop zone area is, the smaller the value of η is.