Transient Startup Analysis of a Space Lithium-Cooled Reactor Coupled with a He-Xe Closed Brayton Cycle

The coupling of a lithium-cooled reactor with a Brayton cycle constitutes a typical design approach for space nuclear power systems. This configuration is predominantly comprised of the following components: a lithium-cooled reactor, heat exchange components (including an intermediate heat exchanger, a cooler, and a recuperator), a turbine-alternator-compressor (TAC) assembly, and a radiator. The present study established a simulation model of a thermoelectric conversion system coupling a lithium-cooled reactor with a helium-xenon Brayton cycle. The model established a steady-state operating condition, and the system’s rationality was validated through comparison with theoretical values. The implementation of three control strategies, integrated with the safety constraints of Brayton cycles in space, resulted in the design of a safe transient startup scheme. The findings indicate that the integrated inventory–shaft speed control strategy effectively ensures the safety of the TAC components.