熔融池相变传热特性的大涡模拟数值研究

Large-Eddy Simulation Numerical Study on Phase Change Heat Transfer Characteristics of Melting Pool

研究反应堆熔融池内部的流动与传热特性对保证熔融物堆内滞留具有重要意义。本文基于开源软件OpenFOAM平台,结合大涡模拟湍流方法和熔融池相变过程建立熔融池传热模型,针对典型熔融池传热实验LIVE工况开展数值计算,得到了熔融池内速度场和温度场以及下封头内壁面硬壳厚度和热流密度分布情况。结果表明,熔融池内速度、温度和热流密度随高度或径向角度的增大而增大;硬壳厚度随径向角度的增大而减小;下封头壁面上的热负荷在顶部聚集。传热参数计算结果与实验数据整体符合较好,可以有效反映出熔融池内自然对流与相变过程,验证了计算模型的可靠性,可为进一步研究熔融池相变传热特性提供参考。

The research of flow and heat transfer characteristics in reactor melting pool is of great significance to ensure the in-vessel retention.Based on the open source software OpenFOAM platform,combined with the large-eddy simulation turbulence method and the phase change process of the melting pool,this paper establishes the heat transfer model of the melting pool,carries out numerical calculation for the LIVE working condition of the typical melting pool heat transfer experiment,and obtains the velocity field and temperature field in the melting pool,as well as the thickness and heat flux distribution of the hard shell on the inner wall of the lower head.The results show that the velocity,temperature and heat flux density in the melting pool increase with the increase of height or radial angle,the thickness of the hard shell decreases with the increase of radial angle,and the heat load on the wall of the lower head accumulates at the top.The heat transfer parameter calculation results are in good agreement with the experimental data as a whole,which can effectively reflect the natural convection and phase change process in the melting pool,verify the reliability of the calculation model,and provide a reference for further research on the phase change heat transfer characteristics of the melting pool.