On LBE natural convection and its water experimental simulation

• It studies LBE flow stability and distribution under natural convection conditions.
• Stability analysis is done based on a simplified integral flow model.
• Flow similarity laws between water and LBE are presented.
• They hold not only globally, but also locally.
• The water experiment can be used for simulation of LBE natural convection flow.

This paper deals with stability and distribution of coolant flow in a pool type of lead-bismuth eutectic (LBE) cooled accelerator driven system (ADS) under natural convection conditions. Two approaches are proposed for solving the problems, namely, (i) theoretical model for stability analyses; (ii) water experimental simulation for the flow distribution in the natural convection state.The stability analysis is carried out based on a simplified integral flow model, where hot and cold free surface oscillations are taken into account. There is a transition from an absolutely stable state under the forced convection condition to a damped oscillation state under the natural convection condition.Reynolds, Richardson (Grashof) and thermal power similitude laws are revealed for the water experimental simulation. The water model scale, power and other factors can be determined by the similitude laws. By choosing the inlet and outlet temperatures even the local Reynolds number law can be approximately satisfied. By the variation of the inlet temperature in the water experiment several similitude solutions are presented. In particular, they are shown in detail for the model scale one to one. It is concluded that the water experiment can be applied for the simulation of LBE natural convection flow in a pool type of reactor.