摘要
基于对大压差下静止氨水溶液表面吸收氨蒸气过程中热质传递现象的分析,建立了该吸收过程传热传质相互耦合的数学物理模型。在氨蒸气压力不变的情况下,推导出氨水溶液温度场、浓度场以及表征相界面传质的无量纲准则数的理论表达式,结果证明:相界面处氨浓度、温度均为定值,该值只取决于吸收的初始条件。在引入氨水相平衡方程的前提下,拟合出了传质准则数与初始压差、氨水溶液初始参数的半经验关联式,获得了一定初始条件下时均传质量随时间的变化曲线。曲线显示:在吸收开始时,时均传质量最大,随着吸收时间的增加,时均传质量迅速下降。
In this paper, heat and mass transfer during the process of ammonia vapor absorbed into the surface of stagnant ammonia-water solution under the condition of large pressure difference was studied. Physical and mathematical models of the absorption process with cou- pled heat and mass transfer were established. The temperature field, concentration field and the dimensionless number which represents the mass transfer at the interface were developed with constant ammonia vapor pressure. The results indicate that the concentration and temperature at the interface are fixed values which only depend on the initial conditions. By introducing the ammonia-water gas-liquid phase equilibrium equation, the semi-empirical correlation containing criterion number, initial pressure differential and initial parameters of ammonia-water solution was developed. The variation curve between time-averaged mass transfer and the absorption time was obtained. The curve shows that the time-averaged mass transfer is the largest at the beginning of the absorption and drops rapidly as the absorption time increasing.
出处
《制冷学报》
CAS
CSCD
北大核心
2014年第2期1-5,共5页
Journal of Refrigeration
基金
国家重点基础研究发展计划(973计划
2010CB227300)资助项目~~
关键词
氨水吸收
传热传质
数学模型
传质关联式
ammonia-water absorption
heat and mass transfer
mathematical model
mass transfer correlation
