高温气冷堆进气事故中自然循环建立时间及影响因素分析

Analysis of Onset Time of Natural Circulation Process and Influence Factor in Air Ingress Accident of HTR

摘要: 进气事故是高温气冷堆所关注的一类超设计基准事故，其中堆芯内外建立稳定自然循环的时间是该事故所重点关注的一个问题。日本山梨大学Tesuaki Takeda教授提出了局部自然对流会对此过程造成影响，并进行了相关实验。本文通过FLUENT程序对该实验进行了模拟计算，计算结果与实验结果相吻合，验证了FLUENT程序在处理此类问题的能力。另外，通过CFD程序可更方便地对自然循环建立过程的敏感因素（如温度、几何结构、阻力系数等）进行分析，所得结果为模块式高温气冷堆进气事故分析提供了依据。

Abstract: Air ingress accident is a kind of beyond design basis accident in HTR, and the onset time of the stable natural circulation is concerned in this accident. Professor Takeda suggested that the local natural convection in the core played an important role in this phenomenon in 2013, and an experiment was carried out to prove it. FLUENT code was used to simulate this experiment, showing good agreement with it, which verified the ability of FLUENT to solve problems of this kind. On the other hand, analysis of influence factors (such as temperature, resistance and geometry) is much convenient with CFD code. The results provide basement to the further analysis of air ingress accident of HTR.