Thermodynamic analysis of the AMTEC ‐based nuclear power system under time‐varying characteristic of the lunar surface

Abstract

The thermodynamic performance of the lunar surface nuclear power system based on alkali metal thermal electric converter (AMTEC) is analyzed based on the energy conservation of the system. A general mathematical model of the system has been proposed, and the time-varying characteristic of the lunar surface is evaluated. The effects of nuclear reactor parameters, electrode current density of AMTEC, heat rejection parameters and time in a rotational period are considered systematically. Results show that the performance of the lunar surface nuclear power system is unstable during a rotational period. Both of the conversion efficiency (ηs) and output power (P) are higher and steadier during the dark time than during the day time. ηs and P decrease first and then increases, and both of them achieve extreme values on the seventh day. Furthermore, higher nuclear reactor parameters (Tin, Qin) and electrode current density of AMTEC (J) can make positive effect on ηs. The peak conversion efficiency of the power system is about 29.6% when the reactor parameters and electrode current density of AMTEC are 500 kW, 1200 K and 10 000 A/m2, respectively. In short, the time-varying characteristic of the lunar surface makes the thermodynamic property of nuclear power system more complex than ground-based energy system.