氯化钙溶液液滴真空闪蒸再生的实验研究

Concentrating CaCl_2 Droplets by Fast Evaporation of Water in Vacuum

基于探索氯化钙除湿溶液液滴在真空闪蒸过程中的再生机理,搭建了液滴真空闪蒸特性研究的实验台。针对真空压力、液滴初始半径、初始温度、初始浓度等因素对氯化钙液滴闪蒸特性的影响,进行了多组实验研究。实验结果表明:真空压力是影响液滴闪蒸速度的关键因素,真空压力越低液滴闪蒸速度越快,且浓缩后达到的最低温度越低;液滴初始尺寸越小,液滴达到的最低温度也越低,且达到最低温度所用时间也越短;液滴的初始温度对液滴的终态温度没有影响,较高的初始温度可以促进液滴中的水分蒸发,促进除湿溶液的再生;液滴初始浓度也是影响闪蒸效率的因素之一,溶液初始浓度高会导致闪蒸的强度下降。

A novel technique was developed to rapidly concentrate dilute liquid desiccant CaC12 in vacuum. The ef- fects of vacuum evaporation conditions, including but not limited to the pressure, initial temperature, initial concentration and size of CaC12 droplet, on the removal rate of water were experimentally investigated. The preliminary results show that the pressure, CaC12 droplets＇ initial temperature, size, and concentration affect water evaporation to varying degrees. For example, as the pressure decreased, water was evaporated increasingly faster, resulting in colder droplets. Smaller droplets took shorter time to end up with a lower temperature. A higher initial temperature led to a faster＇removal rate of water, but little affecting the final temperature of the concentrated liquid desiccant. It took a shorter time to regenerate the liquid desiccant with a higher CaC12 concentration.