CFD Modeling And Analysis Of Supercritical Natural Circulation Loop

Super-Critical Water-cooled Reactor (SCWR), as the only water-cooled reactor of 6 Generation IV Nuclear Energy Systems chosen by Generation IV International Forum (GIF), has many comprehensive advantages in economy, continuity and sustainability. Study of the behavior of water at supercritical state is very important for developing Super-Critical Water-cooled Reactor (SCWR). A supercritical natural circulation loop is modeled and analyzed in this thesis to study the characteristics of the heat transfer and flow conditions of the supercritical water numerically, by using the CFD software ANSYS CFX.Firstly the Computational Fluid Dynamics (CFD) and the ANSYS CFX software have been introduced in this thesis, and then the process of modeling and simplifying the supercritical natural circulation loop is described. Due to the strong variation of the thermal-physical properties of supercritical water in the vicinity of the pseudo-critical point, the behaviors of water in supercritical condition are significantly different from that in sub-critical condition. The heating power-flow chart of the supercritical natural circulation loop is created through numerical simulating. It is found that the heating power-flow chart can be divided into three important regions: the positive slope region, the transition region and the negative slope region.The impact of the flow resistance on the working condition of the supercritical natural circulation loop is also studied in this thesis. It is found that by increasing the flow resistance, the heating power required for achieving the maximum flow can be reduced, and the stability of the heat transfer and flow of supercritical water can be enhanced too.