AUTHOR=Zhang Li , Guo Pengya , Yuan Yidan , Liang Yangyang , Guo Yong , Li Wei , Guo Qiang , Ma Weimin 

TITLE=Numerical simulation of natural convection and heat transfer in a molten pool with embedded cooling tubes

JOURNAL=Frontiers in Energy Research

VOLUME=Volume 10 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/energy-research/articles/10.3389/fenrg.2022.892592

DOI=10.3389/fenrg.2022.892592

ISSN=2296-598X

ABSTRACT=This study described the natural circulation and heat transfer of a molten pool in a specific designed core catcher conceived for a pressurized water reactor. In addition to external cooling, the core catcher features internal cooling tubes embedded in the molten pool. To investigate the coolability in such configuration, firstly a full scale core catcher simulation is conducted to give a preliminary study under real SA situation. Results illustrated that cooling efficiency can be remarkably enhanced due to the inner tubes. Then a test facility of 2D slice with the geometrical scaled factor of 1:4 has been developed, and molten salt (NaNO3-KNO3) experiments will be implemented in the near future. This paper also performed a pre-test simulation using molten NaNO3-KNO3 as simulant to study the heat transfer and flow characteristics of the salt pool. The melt convection in the test section was represented by two-dimensional mesh with WMLES turbulence model using FLUENT code. The simulation captured the heat transfer enhancement by the cooling tubes as expected and results would help decide the proper test matrix and improvement of instrumentation as to obtain the necessary data for code validation.