Numerical Simulation And Experimental Study On Separation Length Of Fission Gas In Molten Salt Reactor

Thorium-based molten salt reactor is one of the fourth-generation nuclear reactors developed by China.One advantage of the liquid fueled Thorium Molten Salt Reactor?TMSR?is that the fuel can be burned up deeply with the neutron poisonous gas removal system applied.The fission gas,such as Kr and Xe,which are generated by the fission reaction,can be removed by bubbling degassing approach.In order to quantify the separation efficiency for the separator and provide useful guidelines to determine the dimensions for the separator,the separation trajectories of bubbles with different factors in the swirl flow inside the separator are needed.An alternative method to predict the bubble's behavior in separator will be given in the paper,which can avoid the troubleshooting induced by the two-phase simulation.This method is a modified Lagrangian approach in that the continuous phase velocity and turbulence intensity distribution is obtained by a single phase simulation and further approximated by curve fitting,which will be verified by experiment with PIV₂D3C technique.Combing the known velocity distribution with explicit mathematical expression and the interaction model for the gas-liquid interface,a mathematical model to calculate the bubble motion is well posed.A comparison between the numerical results and the experimental data indicates that the result agrees well with each other.The mathematical expression of the single phase simulation is well verified by PIV measures?As for the separation length concerned,the maximal error is less than 20%.It has theoretical guidance meaning for research on the movement of bubbles in cyclone separator.And the new model can be used to guide the determination of swirl chamber space.