快速减压条件下液滴热动力学行为的实验研究

Experimental Study on Thermal-Dynamical Behaviors of Liquid Droplets During Quick Depressurization

实验研究了快速降压过程中悬挂单水滴闪蒸/冻结过程,得到了典型条件下液滴闪蒸/冻结过程的热动力学特征,并基于实验观测结果,探讨了不凝气体对液滴闪蒸/冻结热动力学过程的影响。实验发现,起始冻结时的液滴过冷度近似为常数,而再辉温度对应于终态蒸汽分压所确定的气固相变平衡温度。这些结果有助于正确预言高真空环境中的液滴闪蒸/冻结特征。

The evaporating-freezing process of single pensile water droplet during quick depressurization is studied experimentally. The typical characteristics of the thermal-dynamical behaviors of this process are obtained. Based on the experimental observations, the influences of non-condensable gases on the process are analyzed and discussed in detail. It is pointed out that the subcooling corresponding to the onset of freezing of the droplet is nearly a constant, and the recalescence temperature is approximatively equal to the vapor-solid equilibrium temperature determined by the partial pressure of vapor at the terminal state. The present results are helpful for predicting correctly the evaoorating-freezing processes of liauid droplets in high vacuum environment.