摘要
补水箱是核反应堆安全系统中的重要设备。事故工况下补水箱内可发生剧烈的直接接触冷凝过程,导致补水箱内压力的迅速降低乃至振荡,影响补水箱的安全注入功能。为提高对补水箱安注行为预测的准确性,本文基于射流速度分布理论和假想管嘴分析方法,考虑液相的温度分层对传热温差的影响,结合补水箱内直接接触冷凝的一般过程,建立了针对性的冷凝传热计算方法。利用该模型对现有实验数据进行了预测,符合良好,初步验证了模型的有效性。相关研究有助于提高补水箱安注过程和相关事故安全分析的准确性。
Core make-up tank is a vital component of the reactor safety system.Under accident conditions,dramatic direct contact condensation may occur in the core make-up tank,causing pressure decrease or oscillation,which would be harmful to its safety injection function.To enhance the prediction accuracy of the process,it is necessary to build a special model to calculate the direct contact condensation phenomenon in the core make-up tank,since in the core make-up tank the steam would go through a steam space before it reaches the liquid surface,which is quite different from the mostly studied conditions,where a pipe is often used to guide the steam to the water.In this paper,the jet flow velocity distribution theory was first employed to estimate parameters like the steam velocity profile and the maximum steam velocity at the interface,and then the hypothesis nozzle analysis method was utilized to get the hypothesis nozzle diameter,the effective velocity,the steam penetration length,the effective steam condensation fraction of the jet flow region,etc.Besides,to properly evaluate the heat transfer temperature difference,based on the conversation of energy,a multi-layer model was used to take the temperature stratification effects into account,and the whole liquid region was further divided into two layers,the hot layer and the cold layer.In this way the heat transfer temperature difference was corrected.Considering the effective steam condensation fraction of the jet flow region and natural circulation region near the water surface,a specific condensation heat transfer model was established based on the interface transport model for the jet flow region and the McAdams correlation for natural circulation region.With the help of the effective steam condensation fraction of the jet flow region,the new model could be used to predict the interface heat transfer of liquid and steam during the whole process of core make-up tank safety injection,including the complete condensation period,the partial condensation period and the natural circulation period.Several sets of transient data from two different experiment systems were used to test the new model,with the core make-up tank initial temperature ranges from 21 to 61℃,and steam generator pressure from 0.15 to 8.7 MPa.It is found that the experimental data could be well predicted,and a clear improvement compared to the origin model of Relap5 can be observed,which preliminarily demonstrates the validation of the model.This research may be helpful for the accurate prediction of core make-up tank safety injection process and the safety analysis of related accidents.
作者
马在勇
张卢腾
朱隆祥
孙皖
曾小康
潘良明
MA Zaiyong;ZHANG Luteng;ZHU Longxiang;SUN Wan;ZENG Xiaokang;PAN Liangming(Key Laboratory of Low-grade Energy Utilization Technologies and Systems,Ministry of Education,Chongqing University,Chongqing 400044,China;Department of Nuclear Engineering and Technology,Chongqing University,Chongqing 400044,China;CNNC Key Laboratory on Nuclear Reactor Thermal Hydraulics Technology,Nuclear Power Institute of China,Chengdu 610041,China)
出处
《原子能科学技术》
EI
CAS
CSCD
北大核心
2022年第8期1506-1514,共9页
Atomic Energy Science and Technology
基金
国家自然科学基金(11905021,52176001)
核反应堆系统设计技术重点实验室运行基金。
关键词
补水箱
直接接触冷凝
模型开发
模型验证
core make-up tank
direct contact condensation
model development
model validation
