摘要
对单层布液盘和锥形插件组合作用下的多管管束的流动特性和成膜过程进行了CFD数值模拟。采用VOF多相流模型和RNG k-ε湍流模型,三维双精度求解,以空气和水作为工质,边界条件设置为速度入口和压力出口。通过管内液膜形成、出口截面液相分布、降膜管进出口流量变化等方面研究表明,带插件的布液器能很好的改善布膜的均匀性和稳定性。基于液相体积分数,计算分析了管内液膜平均厚度及平均流速,在流量达到一定值时,液膜厚度趋于定值1.28 mm左右,继续增大流量,流速会成比例增加,不利于连续液膜的稳定,也不利于介质在降膜管内的充分蒸发。
The computational fluid dynamics numerical simulation was performed on the cold film flow characteristics and film formation process of multi-tube bundle under the combination of single layer liquid distributed disk and conical plug-in unit. The volume of fluid multi-phase flow model and Re-normalization group k-ε turbulent flow model were used to solve the three-dimensional double-precision method. Air and waterwere used as working medium and the boundary conditions were set as the velocity inlet and the pressure outlet.The liquid film formation,the liquid phase distribution at the outlet section,and the flow rate at the outlet of thefalling film tube were fully investigated in this paper. The results showed that the liquid distributor with plug-insignificantly improved the uniformity and stability of the film. The average thickness and velocity of the liquidfilm in the tube were calculated based on the liquid volume fraction,which demonstrated that the thickness ofthe liquid film tended to be a constant value about 1.28 mm when the flow rate reached a certain value. The current speed increased with increasing the flow rate,which was not conducive to the stability of continuous liquid film,and the sufficient evaporation of medium in the falling film tube.
作者
杨红
陈鑫
李鹏飞
杨颂
何垚
YANG Hong;CHEN Xin;LI Pengfei;YANG Song;HE Yao(School of Mechanical and Electrical Engineering,Wuhan Institute of Technology,Wuhan 430205,China;Hubei Key Laboratory of Chemical Equipment Intensification and Intrinsic Safety（Wuhan Institute of Technology）,Wuhan 430205,China;Shenzhen Pure Water No.1 Water Treatment Technology Co.LTD,Shenzhen 518105,China)
出处
《武汉工程大学学报》
CAS
2018年第4期451-454,472,共5页
Journal of Wuhan Institute of Technology
基金
深圳市技术创新计划重点项目(20160610)
武汉工程大学研究生教育创新基金(CX2016027)
关键词
降膜蒸发器
布液装置
冷膜
流动特性
数值模拟
falling film evaporator
liquid distributor
cold film
flow characteristics
numerical simulation
