Dropwise condensation is extremely difficult to accomplish through the nanostructured surfaces for very low surface tension substances, such as the Freon refrigerants. To further improve the laminar film condensation heat transfer of the substances with very low surface tension, rely solely on the super hydrophobic layer might not work. In this work, a three dimensional micro-finned tube was fabricated and a layer of polymer coating was deposited outside the fins. Condensation of two substances, R1234ze(E) and R134a, were investigated at saturation temperature 30 and 40℃. Under the coupling effect of coating and fins, the condensing heat transfer coefficient can be up to 28 times larger than the smooth tube and the value can reach 43 kW/m²K at heat flux 20 kW/m². In the lower heat flux, it can be 150% higher than the same finned tube without polymer coating. As the condensing heat transfer enhancement with only fin structure modifications would soon reach its limit, it should have a good application prospect for the micro-fins with surface treatment.

对于表面张力非常低的物质，例如氟利昂制冷剂，通过纳米结构表面实现滴状冷凝是极其困难的。为了进一步提高表面张力非常低的物质的层流膜冷凝传热，仅仅依靠超疏水层可能是行不通的。在这项工作中，制造了一个三维微翅片管，并在翅片外沉积了一层聚合物涂层。研究了两种物质 R1234ze(E) 和 R134a 在饱和温度 30 和 40℃ 下的缩合。在涂层和翅片的耦合作用下，冷凝传热系数可达光滑管的28倍，在热通量20 kW/m ^{2 时}可达43 kW/m ² K. 在较低的热通量下，它可以比没有聚合物涂层的相同翅片管高 150%。由于仅改进翅片结构的冷凝传热增强很快就会达到极限，因此经过表面处理的微翅片应该具有良好的应用前景。