矩形通道堵流过冷沸腾特性研究  

Numerical Research on Subcooled Boiling Characteristics Underthe Blockage Accident of the Plate Type Fuel Element

作　　者：毛辉辉[1,2] 王阳阳 巫英伟[3] 陆祺 刘余[1,2] 杨小磊 MAO Huihui;WANG Yangyang;WU Yingwei;LV Qi;LIV Yu;YANG Xiaolei(Science and Technology on Reactor System Design Technology Laboratory,Nuclear Power Institute of China,Chengdu of Sichuan Prov.610041,China;Nuclear Power Institute of China,Chengdu of Sichuan Prov.610041,China;School of Nuclear Scienceand Technology,Xi'an Jiaotong University,Xi'an of Shaanxi Prov,710049,China)

机构地区：[1]中国核动力研究设计院核反应堆系统设计技术重点实验室,四川成都610041 [2]中国核动力研究设计院,四川成都610041 [3]西安交通大学核科学与技术学院,陕西西安710049

出　　处：《核科学与工程》2020年第2期169-178,共10页Nuclear Science and Engineering

基　　金：国家自然科学基金(11905212)的资助。

摘　　要：由于矩形冷却通道具有很大的长宽比,冷却剂中异物在长期运行过程中在矩形冷却通道内逐渐累积,会使流通面积减小导致局部冷却剂的堵流事故,从而威胁燃料元件完整性。本文在充分考虑燃料组件矩形窄通道流动与换热特性基础上,选取合适的过冷沸腾特性数学物理模型,并采用RELAP5程序计算结果对比验证了数学物理模型的适用性。对堵流工况下运行压力、入口过冷度、功率密度、功率分布、入口不加热段长度等重要运行参数进行敏感性分析,研究其对温度分布以及空泡份额的影响。结果发现改变功率分布对于堵流后果的影响最显著,对称的功率分布输入下燃料元件的释热效果明显好于其他两种非对称功率分布,而且在对称功率分布下堵塞流道冷却剂的局部温度峰值也有所提高,余弦分布形式下堵塞通道内冷却剂峰值温度相对非对称分布高10K左右。余弦分布和功率峰偏上分布形式下,堵塞通道内冷却剂发生局部沸腾,空泡份额分别为0.12和0.009。The cumulated impurities or minor components may be deposited in the rectangular channel during the long term operation of nuclear reactors which adopt the plant fuel assembly.However,the rectangular coolant channel within the plate fuel assembly is narrow.Flow blockage in the rectangular fuel assembly can lead to the Loss of Flow Accident,and the cladding integrity can be threatened.Considering the flow and heat transfer characteristics of the plate fuel assembly,the appropriate physical models for its subcooled boiling analysis was carefully selected in this study.The applicability of these models was verified and validated through a interpretation of a single tube heating experiment.Sensitivity analysis of important operating parameters such as operating pressure,inlet undercooling,operating power,power distribution and length of inlet unheated section was carried out.Among the five key parameters,the power profile has the greatest influence on the result of flow blockage accident.And,heat transfer capability of plate assembly with symmetric power distribution is much better,while its local coolant peaking temperature is a bit higher.When power distribution was in cosine function,the peak temperature of the coolant in the blocked channel is about 10 K higher than that of the asymmetric distribution.When the power distribution was cosine or deflect upwards,boiling occurred in the blocked channel,and the volume friction were 0.12 and 0.009,respectively.

关 键 词：CFD 矩形通道 堵塞工况 过冷沸腾 

分 类 号：TL334[核科学技术—核技术及应用]