Power regulation methods and regulation characteristics of the space reactor direct Brayton cycle with helium-xenon working fluid

The development of long lifespan, high power density, and efficient space power systems is crucial for advancing deep space exploration initiatives. Integration of space reactors with direct Brayton cycles (SR-DBC) represents a promising solution for future space power systems. Effective operation and control of SR-DBC require understanding of their power regulation characteristics. This study established a dynamic model for SR-DBC, from which three power regulation methods were derived: control drum, pump, and bypass valve. An investigation of SR-DBC performance under varying regulation methods elucidated application scenarios for these methods. Findings indicate that at 60 % of rated power generation, control drum regulation achieves the highest efficiency of 16.70 % and rapid response time of 80 s, making it suitable for off-design conditions. Conversely, pump regulation yields a moderate efficiency of 14.87 % but a slower response time of 347 s, primarily due to radiator thermal inertia. Bypass valve regulation exhibits the lowest efficiency at 12.65 % but compensates with the quickest response time of 14 s under reduced power generation conditions. This study provides valuable insights into SR-DBC system operation and control.