Experimental study on flow distribution and mixing at the core inlet of double-loop small module reactor

Abstract

In this paper, an experiment is conducted on a 1/3 scaled-down hydraulic model of SMR to study the flow distribution and mixing characteristics of the reactor, in which the double cold legs and double hot legs are arranged symmetrically. The flow distribution factors and mixing coefficients are obtained by measuring the flow rates and conductivities at the inlet of each fuel assembly simulators, respectively. Especially, the velocity effect on flow distribution and mixing are also analyzed. Results indicate that the flow rate is higher in the central area, and the mixing coefficient decreases with the distance from the injected cold leg. By comparison, the velocity has a slight effect on the flow distribution and mixing, since the turbulent flow is fully developed and has entered self-similar region. Based on this work, the essential data for the structure design, thermal–hydraulic and safety analysis of the SMR are gained.