Session: 04-10: SMRs, Advanced Reactors and Fusion

Paper Number: 135935

135935 - Development of a Liquid Metal Subchannel Code Used in Ocean Conditions and Study the Heat Transfer Characteristics in Rod Bundle of Reactor Core 

Abstract: 

In order to fully consider the opportunities for the use of nuclear energy, the Generation IV International Forum(GIF) researches a kind of fast neutron reactor with liquid metal as coolant. Compared with the traditional Pressurized Water Reactor(PWR), the liquid metal reactor has better heat transfer characteristics and higher heat capacity, and could effectively move the heat generated by the rods of the reactor core in a relatively small system, so it can be modular designed and flexibly installed on a nuclear-powered ship. However, complex ocean environment including heaving and rolling conditions may lead to more severe instability of core flow, thus reducing the safety of the reactor. In addition, the flow and heat transfer characteristics of the core subchannels in the reactor system are very complicated, which is mainly due to the openness of the subchannels leading to the lateral exchange of mass, momentum and energy between channels. Therefore, the study of the flow and heat transfer characteristics of liquid metal under ocean conditions is very important for the application of liquid metal reactor in the offshore engineering.

 

In this study, a thermal hydraulic ocean version subchannel analysis code is developed for liquid metal reactor core analysis based on the theoretical model of ocean conditions. In the developing process, the ocean conditions are divided into rolling and heaving conditions. During the development of the program, it is found that the research on the characteristics of flow resistance and heat transfer mechanism under ocean conditions is not mature, the theoretical models are not perfect, and there is no widely recognized empirical relationship under ocean conditions. The original empirical model is still used in the first version of the program. Furthermore, the verification and validation of the subchannel program is carried out by comparing the results of high resolution CFD results and experimental data systematically. The simulation results are in good agreement with other codes and experimental data, which shows that the ocean version system code has the capability of thermal hydraulic analysis under ocean conditions.

 

Based on the newly developed subchannel analysis code, this paper focuses on the effects of heaving and rolling parameters on the Scale of Flow Oscillation(SFO). The effects of geometric parameters such as rod Pitch to Diameter ratio P/D, Rod To Wall gap(RTW) are studied. In addition, the boundary conditions of inlet mass flow, the axial and radial uniform and non-uniform heating and turbulent mixing coefficients on the flow and heat transfer under ocean conditions are investigated. The effect of rolling motion on different coolants including liquid meal and water are discussed under ocean conditions. The newly developed subchannel analysis code can well complete the thermal and hydraulic calculation of liquid metal cooled fuel assemblies under ocean conditions, and can provide support for the design and thermal and hydraulic analysis of reactor in ocean environment.

 

Key words: Liquid Metal Cooled Fast Reactors, Ocean environment, Subchannel code, Fluctuation characteristics

 

Presenting Author: Yuanyuan Yin Southeast Univeristy

Presenting Author Biography: Yuanyuan Yin is a graduate student at Southeast University, China. She is studying numerical simulations of flow and heat transfer between fuel rod bundles. Her research interests include computational fluid dynamics, heat transfer, and nuclear fuels.

Authors:

Yuanyuan Yin Southeast Univeristy
Bin Han Southeast University
Xiaoliang Zhu Southeast University
Siwei Qi Southeast University
Shenghui Liu Southeast University
Tianyang Xing Southeast University
Bao-Wen Yang DEQD Institute for Advanced Research in Multiphase Flow and Energy Transfel
Aiguo Liu DEQD Institute for Advanced Research in Multiphase Flow and Energy Transfer