Research on Thermal Disturbance Control in Supercritical Carbon Dioxide Brayton Cycle

To address the potential impacts of non-steady-state heat source conditions on the operating parameters of the supercritical carbon dioxide (SCO
2
) Brayton cycle power generation system in ship power systems, this study establishes a dynamic numerical simulation model of a simplified SCO2 Brayton cycle power generation system using the MATLAB/SIMULINK platform. Based on this model, transient operation characteristics of the system are analyzed. The variations in operating parameters of the thermal cycle system are simulated when flue gas parameters change. The effects of heat source temperature fluctuations on the inlet and outlet parameters of system components and the net power output are analyzed, along with control strategies. The results indicate that during heat source fluctuations, the $CO_{2}$ may operate in a transcritical state, and the system pressure may exceed its maximum tolerable value. After implementing control systems, it is found that when the flow rate remains constant within the system, it is preferable to allow the turbine inlet temperature to vary based on waste heat source fluctuations. The combination of low-temperature and inventory control shows good performance in regulating the system’s minimum temperature and pressure, enabling the system to operate at its optimal design points.