摘要
基于质量与能量守恒原理、热力学理论和相变传热传质原理,建立了单个盐水液滴真空蒸发过程的数学模型,对比理论模拟结果与实验数据,验证了模型的有效性。通过模型计算探讨了液滴的无量纲面积,液滴内部浓度分布和温度分布随时间的变化,理论分析了盐水液滴真空蒸发过程中温度变化的影响因素。结果表明,抽真空过程中,盐水液滴内部存在显著温差,而浓度梯度很小。最终环境压力、液滴初始盐分浓度和初始直径对温度变化影响显著;而液滴初始温度对真空蒸发过程影响很小。
Evaporationof a single brine droplet in vacuum was mathematically modeled, on the basis of conservation laws of mass and energy, thermodynamic theory, and principles of heat and mass transfer in phase transitions, and analyti- cally calculated and experimentally measured. The calculated results were found to agree well with the measured ones. The influence of pumping on the key factorswas calculated, including the variations in the dimensionless area, concentration distribution, and time evolution of temperature distribution inside the droplet. The results show that the pumping has a ma- jor impact on the observabletemperature gradient, but a minor effect on the concentration gradient inside the droplet. The variations in temperatureof the droplet were found to significantly depend on the final pressure, its initial size and salt con- centration,but weakly on its initial temperature. For example, at a lower pressure, a smaller brine droplet with lower salt concentration evaporates faster and becomes colder.
出处
《真空科学与技术学报》
EI
CAS
CSCD
北大核心
2014年第6期565-570,共6页
Chinese Journal of Vacuum Science and Technology
基金
河北省自然科学基金项目(E2012502069)
中央高校基本科研业务费专项资金资助项目(11QG62)
关键词
液滴
真空蒸发
盐分浓度
温度变化
Droplet, Vacuum evaporation, Salt concentration, Temperature variation
