采用VOF（Volume of Fluid）自由表面捕捉方法对盐水液滴蒸发过程中气液界面进行追踪，建立了降压环境下单个盐水液滴的蒸发模型，并通过盐水液滴蒸发的实验数据验证了此模型。通过对盐水液滴在相变过程中的形态变化以及传热传质特性的分析，研究了液滴内部温度、速度、蒸汽分布以及液滴形态等随时间的变化情况，分析了影响盐水液滴降压蒸发过程的主要因素。结果表明：在降压蒸发过程中液滴形态变化和环境中蒸汽的分布会随速度场的变化而变化；蒸发过程中初始盐组分质量浓度越大的液滴蒸发速率越缓慢，最终能达到的液滴最低中心温度越高，且液滴中心温度回升速度越慢、回升时间也越晚；液滴初始温度对蒸发速率影响较大，初始温度越高，表面蒸发速率越快，液滴中心温度回升速度越快。

In this paper,the volume of fluid (VOF) free surface capture method was used to track the gasliquid interface during the evaporation of saline droplet,a single saline droplet evaporation model under depressurization environment was established,and the model was verified by experimental data of saline droplet evaporation. The changes of temperature,velocity,vapor distribution and droplet shape with time were studied by analyzing the morphological change and heat and mass transfer characteristics of saline droplet during the phase transformation process,and the main factors affecting the process of depressurization evaporation of saline droplet were analyzed.The results show that the droplet morphology and the vapor distribution in the environment vary with the change of the velocity field during the depressurization evaporation process; during the evaporation process,the evaporation rate of the droplet with a larger initial salt component concentration is slower,the lowest core temperature of the droplet that can be finally reached is higher,the recovery speed of the core temperature of the droplet is slower,and the recovery time is also later; the initial temperature of the droplet has a greater impact on the evaporation rate. When the initial temperature is higher,the surface evaporation rate is faster,and the temperature at the center of the droplet rises faster.

TK121

国家重点研发项目(2018YFB0604303-02)