Modeling and Control System Design of a New Gas-Cooled Microreactor System

Compared to traditional pressurized water reactors, the new gas-cooled microreactor exhibits significant differences in system characteristics and control methods in the unique core structure and thermal conduction mechanism. To understand the dynamic characteristics of the 4 MW new gas-cooled microreactor system and design a load-following control system, this paper establishes a mechanistic model of the new gas-cooled microreactor through theoretical derivation. The model was validated under both steady-state and transient conditions. The results show that the steady-state error is less than 1% and the transient results were consistent with the mechanistic model. It is demonstratd that the established mechanistic model can accurately reflect the dynamic characteristics of the new gas-cooled microreactor. Based on this, a dynamic control model was established to analyze the dynamic characteristics. At the 100% power level, 10% step decrease in load level is introduced to simulate and validate the established control scheme. The results show that the designed control system can track changes in the load setpoint, ensuring core outlet temperature and secondary side outlet air temperature of the intermediate heat exchanger constantly. The new gas-cooled microreactor model and control system design studied in this paper can provide technical support for the development of new gas-cooled microreactor technology.