Investigation on Basic Equations and Scaling Criteria of PWR Natural Circulation

With analyzing the characteristic of PWR natural circulation, a set of non-dimensional equations were obtained to describe natural circulation phenomenon for both single phase and two-phase independently from single and two phase one dimensional equations. Thus, a set of scaling criteria deduced from non-dimensional equations is able to be applied to scaling simulation for both single and two phase natural circulation. Then, the essence of scaling simulation of natural circulation and the physical meaning of criteria were discussed with initial parameters of simulation, flow instability simulation, heat transfer and critical heat transfer simulation.