Dynamic performance of the combined stirling thermoelectric conversion technology for a lunar surface nuclear power system

Abstract

The space nuclear reactor power system is one of the most potential energy and power supplies for future lunar science exploration. Unlike the devices on Earth, the devices operating on the lunar surface require a higher level of intelligent and automatic system control. Thus, it is necessary to establish a comprehensive and accurate dynamic system model to improve the system's automatic control. In the present study, a dynamic system model of a lunar surface nuclear power system combined with a Stirling cycle was proposed. The dynamic system model consists of a reactor core model, a heat rejection model, and a Stirling thermoelectric conversion model (while the reactor core is simplified as a point heat source). MATLAB and Simulink platforms are applied to implement the system model. To verify the system model and analyze the dynamic performance, simulations of the several reactor startup processes, different reactor thermal power (reactivity disturbances), and different lunar surface temperature conditions were carried out. The results show that the effects of thermal power variation on the dynamic system model have a nonlinear delay. Furthermore, the lunar surface temperature significantly impacts the dynamic system's operation and response. The present study provides a practical tool for the transient analysis of the lunar surface nuclear reactor power system and theoretical support for the design of lunar surface nuclear reactors.