摘要
含空气蒸汽冷凝是反应堆失水事故时安全壳内重要的热工水力现象。已有研究多关注气体压力、温度等热工参数对传热特性的影响,而对几何参数的影响及其作用原理分析较少。采用三维CFD数值模拟方法,基于扩散边界层冷凝机理模型研究了管径(4~60 mm)、管长(0.1~7 m)及倾角(0°~90°)对含空气蒸汽冷凝传热特性的影响。结果表明,管径、管长及倾角均对含空气蒸汽冷凝传热特性有显著影响。平均冷凝传热系数随管径的增大而减小;随管长的增长先减小后增大,3 m左右达到最小值;随倾角的增大而增大。局部冷凝传热系数沿管长方向先迅速减小后缓慢增大。倾斜布置时,迎流面产生明显传热强化,向两侧逐渐减弱,背流面存在一定的传热抑制。
Steam condensation in the presence of air is an important thermal-hydraulic phenomenon in containment under loss of coolant accidents(LOCAs)or main steam line break accidents(MSLBs).Previous studies have focused on the effects of thermal parameters such as air mass fraction,gas pressure and sub-cooling on heat transfer characteristics,but less on the influence and action principle of geometric parameters such as tube length,tube diameter and inclination angle.Fully understanding the influence of geometric parameters on condensation heat transfer of steam containing air is of great significance for efficient heat transfer,so as to improve the safety and economy of related applications.The effects of tube diameter(4-60 mm),tube length(0.1-7 m)and inclination angle(0°-90°)on condensation heat transfer characteristics of air containing steam were studied based on the diffusion boundary layer condensation mechanism model by using three-dimensional CFD numerical simulation method.The results show that the tube diameter,tube length and inclination angle have significant effects on condensation heat transfer characteristics of air containing steam.However,when tube diameter exceeds 30 mm,tube length exceeds 1 m and inclination angle exceeds 60°,the average condensation heat transfer coefficient is no longer sensitive to the change of geometric parameters.The average condensation heat transfer coefficient decreases with the increase of tube diameter,and the descent speed decreases rapidly.When the tube diameter is 4 mm,the average condensation heat transfer coefficient is twice that of 60 mm.It first decreases and then increases with the increase of tube length,and reaches the minimum value at about 3 m.And it increases with the increase of inclination angle.The high concentration air layer near the wall is the main thermal resistance in the condensation process of steam-air,and its thickness makes a good negative correlation with condensation heat transfer coefficient.The high concentration air layer will first accumu
作者
肖家禹
孙中宁
李荣绩
李文涛
丁铭
曹夏昕
边浩志
XIAO Jiayu;SUN Zhongning;LI Rongji;LI Wentao;DING Ming;CAO Xiaxin;BIAN Haozhi(Fundamental Science on Nuclear Safety and Simulation Technology Laboratory,Harbin Engineering University,Harbin 150001,China)
出处
《原子能科学技术》
EI
CAS
CSCD
北大核心
2022年第10期2069-2077,共9页
Atomic Energy Science and Technology
基金
国家自然科学基金(11975085)。
关键词
不凝性气体
凝结
管径
管长
倾角
数值模拟
non-condensable gas
condensation
tube diameter
tube length
inclination angle
numerical simulation
