A control strategy for supercritical carbon dioxide direct cooled nuclear power system

Abstract

The supercritical carbon dioxide (S-CO₂) direct cooled nuclear power system is an energy conversion system that utilizes S-CO₂ as the medium to transform nuclear thermal energy into electrical or mechanical power through a direct cycle. It offers advantages such as system simplification, compact structure, high maneuverability, and superior thermal efficiency. However, the system poses significant control challenges due to its characteristics of strong multi-equipment coupling, wide parameter variations, and complex physical processes. To address the coordination of highly variable external load demands, it is important to investigate its control strategy. In this paper, a simulation model of the S-CO₂ direct cooled nuclear power system is established on the MATLAB/Simulink. Through dynamic characteristic analysis under typical operational modes, including step transient conditions, linear transient conditions, and load rejection transient conditions, a hybrid throttling-bypass control strategy is proposed. Specifically, the throttling control subsystem is designed to manage step transient conditions and linear transient conditions requirements, while the bypass control subsystem is designed for load rejection transient conditions. Simulation results demonstrate that the proposed control strategy achieves good control performance for the S-CO₂ direct cooled nuclear power system. This paper provides valuable reference for the design of control systems in S-CO₂ direct cooled nuclear power system.