真空环境中黏性流体沿凹型壁面降膜流动行为的数值模拟  

Numerical simulation of the falling film flow behaviors of viscous fluid along concave walls in vacuum environment

作　　者：林文博 高祥 陈世昌[1] 陈文兴[1] LIN Wenbo;GAO Xiang;CHEN Shichang;CHEN Wencing(National Engineering Lab for Textile Fiber Material and Processing Technology,Zhejiang Sci-Tech University,Hangzhou 310018,China)

机构地区：[1]浙江理工大学纺织纤维材料与加工技术国家地方联合工程实验室,杭州310018

出　　处：《浙江理工大学学报（自然科学版）》2022年第6期864-872,共9页Journal of Zhejiang Sci-Tech University(Natural Sciences)

基　　金：国家自然科学基金项目(52173047,51803187);浙江省重点研发计划项目(2021C01020)。

摘　　要：物料在设备内的流动行为对材料加工结果具有重要影响,提出采用计算流体力学数值模拟技术探究黏性流体沿凹型壁面降膜的流动行为。在考察不同流场环境压力对流体降膜流动行为影响的基础上,探究了真空环境中变换流体物性参数和操作参数时降膜流动的自由面、特征位置的膜厚和速度场等成膜流动特性。结果表明:提高降膜流场环境的真空度,液膜的成膜厚度变小,有利于提高脱挥设备内的物料传质速率;特征面速度随着角度的增大而逐渐增大,在45°时达到最大;当黏度为130.00 Pa·s的流体进行降膜流动时,其成膜效率最高可达12000 m^(2)/(m^(3)/s),表现出较好的成膜性能。该研究结果可为降膜脱挥器的设计与开发提供一定参考。The flow behaviors of materials inside the equipment have an important effect on the processing results of materials. In this paper, numerical simulation technique for hydromechanics was used to explore the falling film flow behaviors of viscous fluid along concave walls. Based on a clear understanding for the influence of different flow field ambient pressures on the falling film flow behaviors of fluid, we explored the film-forming flow properties, such as the free surface of the falling film flow, the film thickness at characteristic positions and the velocity field when the physical and operating parameters of the fluid were changed in the vacuum environment. The results indicated that when the vacuum degree of the falling film flow field environment was improved, the liquid film became thinner, which can help improve the mass transfer efficiency in the devolatilization equipment. The velocity of characteristic surface rose with the increase of angle, and reached its maximum at 45°. When the fluid with a viscosity of 130 Pa·s had falling film flow, the film-forming efficiency reached 12000 m^(2)/(m^(3)/s), and the film-forming properties were good. This result can provide a certain reference for design and development of falling film devolatilizers.

关 键 词：降膜流动 脱挥 数值模拟 环境压力 成膜性能 

分 类 号：TQ31[化学工程—高聚物工业]