ABSTRACT The enhanced heat transfer performance of falling film evaporation during desalination through altering smooth tubes by corrugated tubes was investigated. An experimental research on corrugated and smooth tubes was carried out using a horizontal-tube falling-film evaporation heat transfer experimental apparatus. The changes in heat transfer coefficient with the process parameters (sprinkling density, heat flux, heat transfer temperature difference, and evaporation temperature) were obtained according to the experimental data. The influence of tube type on liquid-film distribution outside the tube was also examined by numerical simulation. Results showed that within a certain scope increasing of any one variable of sprinkling density, heat flux, and evaporation temperature has a positive impact on the heat transfer coefficient. When the sprinkling density exceeded 0.178 kg/(m·s), the heat transfer coefficient tended to be stable. Compared with the simulation results, the liquid film coverage and thickness outside the tube significantly influenced heat transfer efficiency. When the heat flux exceeded 130kW/m2, the growth of the heat transfer coefficient significantly slowed down. Under the same experimental conditions, the heat transfer coefficient of corrugated tubes increased by 30% compared with that of smooth tubes. In addition, the content of non-condensable gas within the seawater affected the heat transfer coefficient significantly.

中文翻译：

---

低温多效降膜蒸发波纹管传热性能研究

摘要 研究了通过用波纹管改变光滑管来提高脱盐过程中降膜蒸发的传热性能。利用水平管降膜蒸发传热实验装置对波纹管和光滑管进行了实验研究。根据实验数据得到传热系数随工艺参数（喷淋密度、热通量、传热温差和蒸发温度）的变化。还通过数值模拟研究了管类型对管外液膜分布的影响。结果表明，在一定范围内，增加洒水密度、热通量和蒸发温度中的任何一个变量对传热系数都有积极的影响。当洒水密度超过0.178 kg/(m·s)时，传热系数趋于稳定。与模拟结果相比，管外液膜覆盖率和厚度显着影响传热效率。当热通量超过130kW/m2时，传热系数的增长明显放缓。在相同的实验条件下，波纹管的传热系数比光滑管提高了30%。此外，海水中不凝气体的含量对传热系数影响显着。当热通量超过130kW/m2时，传热系数的增长明显放缓。在相同的实验条件下，波纹管的传热系数比光滑管提高了30%。此外，海水中不凝气体的含量对传热系数影响显着。当热通量超过130kW/m2时，传热系数的增长明显放缓。在相同的实验条件下，波纹管的传热系数比光滑管提高了30%。此外，海水中不凝气体的含量对传热系数影响显着。