Reliability and loading-following studies of a heat pipe cooled, AMTEC conversion space reactor power system

During the progress and development of the space technology, the space reactor power system (SRPS) is one of the best options for providing high power density, long-term life, light weight, and high reliability space power for civil or military space missions. The heat pipe cooled SRPS (HPS) equipped with the static conversion technology Alkali Metal Thermal-to-Electric Conversion units (AMTEC) has good inherent dynamic characteristic for frequent change load following of the space mission power, with high safety and reliability. This paper analyzed the system safety and reliability of an AMTEC conversion HPS, the load following characteristics of the AMTEC conversion and the HPS's performance in response to partial surface area loss of potassium heat pipe radiator. The results show the following. (1) As the external load resistance increases, the AMTEC thermoelectric conversion efficiency and electric power output both increase to the maximum, and then decrease. The maximum thermoelectric conversion efficiency and electric power output correspond to different critical external load values. The load following capacity of the AMTEC HPS exists only when the external load demands exceed a critical value. (2) When the potassium heat pipe radiator's surface area is partially lost because of the impact of a meteorite, the reactor thermal power, the AMTEC conversion efficiency and the electric power output also decrease, except the radiator temperature due to the radiator area loss. The waste heat rejection, the conversion efficiency and electric power output of the system decrease proportionally to the radiator's surface area loss. To ensure the safety and reliability of the SRPS, the reactor thermal power will run down after the loss of the radiator's surface area. (C) 2019 Elsevier Ltd. All rights reserved.