摘要
以水为工质,在常压下对拥有细长回路和较长水平段的自然循环系统进行可视化实验研究,并以典型的实验现象(P=1.46kW)为例分析该系统的瞬态运行特性和不稳定性机理。结果表明:阻力系数较大的细长自然循环回路难以产生有效的单相自然循环,只能通过间歇性沸腾和两相流动将热量导出。这是因当回路阻力较大时,过冷沸腾产生的驱动力无法驱动回路产生有效的自然循环,而只有当加热段内流体发生饱和沸腾时才能驱动系统产生循环流动。较大的回路阻力和沸腾过程中产生的系统降压闪蒸是细长自然循环系统难以维持稳定的流动驱动压头从而产生间歇性沸腾和强烈流动不稳定性的根本原因。
The visual experimental study with water as the working substance was performed to investigate the operation behavior of a natural circulation system with elongated loops and long horizontal sections at atmospheric pressure ,and the transient operation behavior and instability mechanism of typical experimental phenomenon （ P=1.46 kW） were given .The results show that the single natural circulation in elongated system with the great resistance coefficient is difficult to appear ,but the heat can be removed by two-phase intermittent boiling .The driven force caused by the sub-cooled boiling can not drive the fluid to produce the effective natural circulation because of the great loop resistance ,and the circular flow occurs only when the fluid in heat section produces the saturation boiling .T he big loop resistance and flashing because of pressure drop in boiling process make the elongated natural circulation difficult to maintain a stable flow driven head and they are the fundamental reasons of intermittent boiling and strong flow instability .
出处
《原子能科学技术》
EI
CAS
CSCD
北大核心
2014年第2期267-270,共4页
Atomic Energy Science and Technology
关键词
自然循环
闪蒸
流动不稳定性
natural circulation
flashing
flow instability
