摘要
本文以氟里昂12作工质,对自然循环过冷沸腾流动不稳定性进行了实验研究,实验过程中发现自然循环系统内可能发生高频脉动和低频脉动两类流动不稳定性,并证实高频脉动属于声波型脉动,低频脉动属于密度波型脉动。本文以两相流漂移模型为基础,对自然循环过冷沸腾流动不稳定性进行了数值模拟,数学模型考虑了热力学非平衡即过冷沸腾和过冷凝结对流动不稳定性的影响。数值模拟结果与实验结果符合良好。
This paper presents both the experimental study and theoretical analysis of flow instability
in a natural circulation system with subcooled boiling. Freon-12 was used as the working medium.
It is found from the experiments that two kinds of flow instability, high frequency oscillations and
low frequency oscillations may occur in the natural circulation system with subcooled boiling. The
high frequency oscillations have the characteristics of acoustic oscillations, while the low frequency
oscillations belong to density wave instability. A mathematical model based on the drift flux model
has been developed to analyze the subcooled two-phase flow instabilities in the natural circulation
system. In the mathematical model, the modified Levy model is used to calculate the void fraction in
the heated section. The 'Condensation-time' model is used to predict the void fraction in the unheated
riser. The finite difference equations are solved by using the SlMPLEC method. The caloulated results
are in good agreement with the experimenial data.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2004年第3期435-438,共4页
Journal of Engineering Thermophysics
基金
国家自然科学基金(No.59995461)
空泡物理和自然循环重点实验室2000年基金
关键词
自然循环
过冷沸腾
流动不稳定性
实验研究
数值模拟
natural circulation
subcooled boiling
flow instability
experiment
numerical simulation