INVESTIGATION ON SECONDARY FLOW AND THERMAL IRREVERSIBILITY OF LBE IN THE REACTOR FUEL ASSEMBLY

In the present study, forced convective heat transfer of LBE inside a wire-wrapped fuel bundle is investigated using numerical method based on the FVM and SLA method. To investigate the secondary flow characteristics and thermal irreversibility in the fuel bundle, the commercial CFD code is adopted to solve the fluid flow in the complex fluid domain. The liquid LBE heat by the fuel bundle, which is fixed by the wrapped-wire. However, there are intense secondary flow in the cross-section, which is perpendicular to the flow direction and has a non-negligible effect on the convective heat transfer and thermal irreversibility. The study is conducted for the certain Reynolds number, heat power, and inlet temperature. Results in terms of velocity and temperature field, secondary flow, thermal irreversibility based on the second law analysis are investigated. Numerical results indicate that the secondary flow present a periodical change in axial direction. The irreversible losses are mainly caused by the heat transfer process. Besides, the thermal economic performance shows that the heat transfer economic efficiency increases with the mass flow rate.