严重事故下堆舱空间氢气分布特性数值模拟

Numerical simulation of hydrogen distribution characteristics in reactor space under severe accident

利用计算流体力学软件CFX分析了零方程模型和k-ε模型对氢气分布的影响,并对船用堆在典型失水诱发的严重事故下堆舱空间内的氢气分布特性进行了数值模拟。结果表明:在氢气释放阶段内,用k-ε模型模拟堆舱空间内的氢气分布更为合理;严重事故下的气体喷放期间,堆舱空间内各点处的压力变化基本一致,空间内的温度不会持续升高,氢气在堆舱空间内建立了比较明显的浓度梯度,堆舱顶部区域和破口附近区域氢气浓度都较高;氢气喷放结束后,堆舱空间内的平均水蒸气浓度不足以维持蒸汽惰性环境,堆舱空间内存在氢气燃烧的可能。研究结果为开展船用堆的氢气风险研究提供了基础。

The effects of zero equation model and k-εmodel on hydrogen distribution have been analyzed by computational fluid dynamics program CFX,and the hydrogen distribution characteristics in the reactor space of marine reactor under typical water loss induced severe accident could be numerically simulated.The results show that it is more reasonable to use the k-εmodel to simulate the hydrogen distribution in the reactor space during the concentrated release stage of hydrogen.During the period of severe accidents,the pressure changes at each point in the reactor space could be regarded as basically the same,and the temperature in the space will not continue to rise.Hydrogen forms a relatively obvious concentration gradient in the reactor space.At the top area of the reactor space and the area near the break the hydrogen concentration is abviously rising.After the hydrogen injection,the average vapor concentration in the reactor space is not high enough to maintain the inert environment,and there is a possibility of hydrogen combustion in the reactor cabin space.This study provide a basis for the research of hydrogen risk of marine reactor.