Nuclear Science and Techniques

《核技术》(英文版) ISSN 1001-8042 CN 31-1559/TL     2019 Impact factor 1.556

Nuclear Science and Techniques ›› 2018, Vol. 29 ›› Issue (5): 62

• NUCLEAR ENERGY SCIENCE AND ENGINEERING •

Large eddy simulation of unsteady flow in gas–liquid separator applied in thorium molten salt reactor

Jing-Jing Li 1 • Ya-Lan Qian 1 • Jun-Lian Yin 1 • Hua Li 2 • Wei Liu 2 • De-Zhong Wang 1

1. 1 School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
2 Shanghai Institute of Applied Physics, Shanghai 201800, China
• Contact: Jun-Lian Yin E-mail:jlyin@sjtu.edu.cn
• Supported by:

This work was supported by the National Natural Science Foundation of China (Nos. 11535009 and 51406114).

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Jing-Jing Li, Ya-Lan Qian, Jun-Lian Yin, Hua Li, Wei Liu, De-Zhong Wang. Large eddy simulation of unsteady flow in gas–liquid separator applied in thorium molten salt reactor.Nuclear Science and Techniques, 2018, 29(5): 62

Abstract:

Axial gas–liquid separators have been adopted in fission gas removal systems for the development of thorium molten salt reactors. In our previous study, we observed an unsteady flow phenomenon in which the flow pattern is directly dependent on the backpressure in a gas–liquid separator; however, the underlying flow mechanism is still unknown. In order to move a step further in clarifying how the flow pattern evolves with a variation in backpressure, a large eddy simulation (LES) was adopted to study the flow field evolution. In the simulation, an artificial boundary was applied at the separator outlet under the assumption that the backpressure increases linearly. The numerical results indicate that the unsteady flow feature is captured by the LES approach, and the flow transition is mainly due to the axial velocity profile redistribution induced by the backpressure variation. With the increase in backpressure, the axial velocity near the downstream orifice transits from negative to positive. This change in the axial velocity sign forces the unstable spiral vortex to become a stable rectilinear vortex.