摘要
为研究吸收式制冷机中吸收剂溴化锂水溶液气液界面的微观形态,采用分子动力学方法,分别对不同质量分数的溴化锂水溶液不同温度时气液界面的微观结构、密度分布、界面厚度,溴化锂水溶液界面处和液相处离子与水分子中氢、氧原子的径向分布函数以及离子周围水分子取向角的分布函数进行了计算与分析.模拟结果表明:温度一定时,随着溴化锂水溶液质量分数的增加,液相密度逐渐增加,界面厚度逐渐减小;对于质量分数为60%的溴化锂水溶液,随着温度的升高,液相密度逐渐减小,气液界面厚度增加;303.15K时,质量分数为60%的溴化锂水溶液中界面的出现并未影响离子周围水分子的取向的有序性;随着温度的升高或溴化锂水溶液质量分数的减小,近界面处与液相处周围水分子的结构变得相似,离子周围水分子的取向的有序性不再很明显.
To study the micro-interface configuration of an aqueous LiBr solution which is used as an absorbent in an absorption refrigerator,dynamic molecular simulations were carried out to investigate the microstructure,longitudinal density profile,and interface thickness of the liquid-vapor interface of an aqueous LiBr solution with various concentrations at different temperatures.The radial distribution function between ions and oxygen or hydrogen atoms near the interface or in bulk as well as an orientation angle distribution function for water neighbored by ions were also computed.The simulation results show that liquid density increases while the interface thickness decreases gradually with the increase of the concentration of the solution as the temperature is constant.The liquid density decreases and the interface thickness increases with the increase of the temperature as the solution concentration is constant at 60%.The interface cannot affect the orientation order at 303.15K with the solution concentration at 60%.Water structures neighbored by ions in the interface and in bulk are similar and the orientation order is not distinct with the increase of the temperature or the decrease of the solution concentration.
出处
《哈尔滨工程大学学报》
EI
CAS
CSCD
北大核心
2011年第6期754-759,共6页
Journal of Harbin Engineering University
基金
国家自然科学基金资助项目(50476038
50976015)
关键词
溴化锂水溶液
密度分布
分子动力学
气液界面
aqueous LiBr solution
density profile
molecular dynamics
liquid-vapor interface
