一体化小型自然循环反应堆流动非对称性机理分析

Analysis of Asymmetry Flow in Integrated Small Natural Circulation Reactor

为研究一体化小型自然循环反应堆稳态条件下的流动非对称性机理,通过总结当前国际自然循环反应堆的主要设计特征,建立了自然循环典型三维分析模型,采用计算流体动力学(CFD)方法对竖直稳态下自然循环进行了数值模拟,并针对不同混流截面的速度和温度分布特性进行了分析。结果表明:较大尺度的自然循环系统在理想竖直稳态自然循环条件下,存在周向的流量和温度分布不均匀性,其中流量分配的不均匀性较温度分布情况更突出。竖直稳态自然循环的主流流量和温度均呈现偏心趋势,属于系统层面的偏差,而不只是局部流动分配不均衡问题。

The main design features of the current international natural circulation reactor were summarized,and a typical analysis model was established in this paper.Based on CFD simulation,the characteristics of velocity and temperature distributions of different sections in the reactor were analyzed.The results show that the large-scale natural circulation system has circumferential flow and temperature distribution inhomogeneity under ideal vertical steady-state natural circulation conditions.The inhomogeneity of the flow distribution is more prominent than that of the temperature distribution.The mainstream flow and temperature of the vertical steady natural circulation show an eccentric tendency,which is a system-level deviation,not just a partial flow distribution imbalance.