摘要
为了提高氨水发生效率,在氨水溶液中添加纳米颗粒形成纳米流体,将发生过程中降膜溶液膜厚的变化、膜厚方向的对流以及氨水纳米溶液物性的变化作为影响因素,建立了垂直管外氨水降膜发生过程数学模型.通过对该数学模型进行数值求解,得到平均传热系数、传质系数、发生速率随质量流量、氨水浓度、发生压力以及热负荷的变化情况.结果表明,选择合适比例的氨水纳米溶液对降膜发生过程具有一定的强化作用.添加纳米的氨水纳米流体较氨水基液平均传热系数增加约4%;平均传质系数增长约15%;发生速率平均增长约25%.所得模拟结果与实验值吻合较好.
To enhance the efficiency of falling film generation process,nanoparticles were added into solution to form ammonia-w ater nanofluid. Based on the change of film thickness,the convection in the film thickness and the change of physical properties of ammonia solution during the generation process,a mathematical model describing the process of falling film generation process outside the vertical tube was established. Through numerical solution of the mathematical model,the average heat and mass transfer coefficient and the rates of generation vary with mass flow,ammonia concentration,pressure and heat load were obtained. The simulation results show that the proper amount of nanoparticles had a certain strengthening effect on the falling film generation process. Compared with the solution without nanoparticles,with the addition of nanoparticles the average heat transfer coefficient increases by about 4%,the average mass transfer coefficient increase by about 15%,and the average generation rate increases by about 25%. The simulation results are in good agreement with the experimental results.
作者
李彦军
李舒宏
陈向阳
杜垲
杨柳
Li Yanjun1,2 Li Shuhong1,Chen Xiangyang2, Du Kai1, Yang Liu1(1. School of Energy and Environment, Southeast University, Nanjing 210096, China; 2. Jiangsu Product Quality Testing and Inspection Institute, Nanjing 210007, Chin)
出处
《东南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2018年第3期427-434,共8页
Journal of Southeast University：Natural Science Edition
基金
国家自然科学基金资助项目(51476026)
"十三五"国家科技支撑计划资助项目(2017YFC0702501)
江苏省自然科学青年基金资助项目(BK20150607)
关键词
降膜发生
氨水
纳米流体
模型
传热
传质
falling film generation
ammonia-water
nanofluid
model
heat transfer
mass transfer
