低压闪蒸液滴形态和温度变化的研究

将液滴在常压下突然置于低压环境中,液滴由最初的平衡状态变成过热状态,发生闪蒸.本文实验研究了低压闪蒸液滴内部形态和温度的变化,系统描述了液滴闪蒸过程中的各种形态变化,总结了稳态闪蒸和稳态结冰过程中环境压力和初始温度对温度变化的影响.实验结果表明液滴闪蒸分六种形态.稳态闪蒸中环境压力越低,液滴的最终温度也越低;液滴的初始温度越高,降到最低温度的时间越长.稳态结冰过程中,液滴初始温度增加,液滴结冰温度和结冰回升最高温度也随之增加;液滴的结冰温度和回升最高温度随环境压力的增高而减小.

STUDY ON THE SHAPE AND TEMPERATURE VARIATIONS WITHIN DROPLET IN LOW PRESSURE ENVIRONMENT

When a water droplet is placed suddenly into low-pressure environment from an atmo- spheric pressure,it changes from initial equilibrium state to superheated state,so flashing begins.The variations of the shape and temperature within the droplet are described,and the effect of environ- ment pressure and initial temperature on the temperature variation during stable evaporation and stable freezing process was summed up.The experimental results show that the flash of droplet can be divided into six kinds of shape.During a stable evaporation process,the ultimate temperature declined with a decrease in environment pressure,and it used more time dropping to the ultimate temperature when the initial droplet temperature was higher.While in stable freezing process,the freezing start temperature and the highest recovery temperature were both increased with an increase in initial droplet temperature,but they were declined when the environment pressure was increased.