摘要
采用实验研究手段,在可视化矩形容器内构造多组分液体分层系统,通过分析不同质量分数差和侧壁漏热下容器内流体的分层演化规律和温度响应情况,揭示初始浮力比(Rρ)对系统失稳形态、分界面移动速度、失稳积聚能量和分层系统稳定性的影响。结果表明随着初始浮力比的增大,分层结构失稳形态和分界面移动速度呈现不同规律,且存在临界初始浮力比(Rρc)使分层系统保持稳定。当初始浮力比较低时(Rρ≤0.35),边界浮升流穿透分界面后可到达液体表面,掺混区域位于上层液体上部,分界面下移速度整体较快,后期逐渐减慢;当初始浮力比较高时(0.47≤Rρ≤Rρc),边界浮升流不能到达液体表面,掺混区域主要位于上层液体侧部,分界面下移速度整体较慢,后期逐渐加快。同时发现,随着初始浮力比的增加,分界面穿透时间延后,分层失稳时积累能量越多,这导致漏热率相同时,初始质量分数差较大的情况更加危险;而质量分数差相同时,可能存在漏热率低而更危险的情况。
The experimental study method was used to construct a multi-component liquid stratification system in a visual rectangular container.The effects of initial buoyancy ratio(Rρ)on the instability pattern,the moving speed of the interface,energy accumulated during instability and the stability of the stratified system were studied by analyzing the stratification evolution and temperature response under different mass fraction differences and sidewall leakage.The study showed that with the increase of the initial buoyancy ratio,the instability pattern and the moving speed of the interface exhibit different laws,and the critical initial buoyancy ratio(Rρc)keep the system stable.When the initial buoyancy was low(Rρ≤0.35),the boundary floating flow could reach the liquid surface after penetrating the interface,the mixing area was located in the upper part of the upper liquid.The downward velocity of the interface was generally faster,but gradually slowed down later.When the initial buoyancy was high(0.47≤Rρ≤Rρc),the boundary floating flow could not reach the liquid surface,the mixing area was mainly located at the side of the upper liquid.The downward velocity of the interface was generally slower,but gradually accelerated later.Finally,it was found that with the increase of the initial buoyancy ratio,the interface penetration time was delayed,and the energy accumulated during instability was more.When the heat leakage rate was the same,a situation with the large initial mass fraction difference was more dangerous.When the mass fraction difference was the same,there may be a case with the low heat leak rate was more dangerous.
作者
张瀚
任婧杰
沙嵬
周一卉
毕明树
ZHANG Han;REN Jingjie;SHA Wei;ZHOU Yihui;BI Mingshu(School of Chemical Machinery and Safety Engineering,Dalian University of Technology,Dalian 116024,Liaoning,China)
出处
《化工进展》
EI
CAS
CSCD
北大核心
2019年第10期4481-4488,共8页
Chemical Industry and Engineering Progress
基金
国家自然科学基金(51506025)
关键词
初始浮力比
分层系统
不稳定性
对流
扩散
initial buoyancy ratio
stratification system
instability
convection
diffusion
