Experimental and simulation investigation of lunar energy storage and conversion thermoelectric system based on in-situ resource utilization

The harsh lunar environment and prolonged periods of darkness pose significant challenges for lunar exploration. Ensuring a sufficient and continuous energy supply is essential for the survival of astronauts and lunar surface equipment. In-situ resource utilization thermoelectric generator (ISRU-TEG) system is one of the most promising methods for sustained power supply throughout the lunar night. In this study, an experimental setup of the ISRUTEG system consisting of near-adiabatic regolith and a heat storage unit functioning as a heat transfer station is developed. Then, a transient thermoelectric mathematical model for the experimental process is proposed, and the experimental validation of theoretical models is conducted, which demonstrates the feasibility of the ISRUTEG system in practice and the validity of the mathematical model. The results of the experimental verification indicate that the energy conversion efficiency of the TEG system increased with input power, reaching a maximum of 1.19 % at an input power of 10.12 W, and the power output of the heat storage unit after precooling increased by 63.8 % during the low-temperature stage. Finally, the operating performance of the ISRU-TEG system on lunar surface throughout 3 lunar day-night cycles was evaluated, the results indicate that the power output during the lunar night is 0.111 MJ, which is 18.59 % of the total power output (0.597 MJ). Furthermore, the optimal size of the thermal storage unit is a radius of 200 mm and a height of 500 mm, and a thermal conductivity greater than 0.5 W/m & sdot;K is suitable for the heat storage unit. In conclusion, this work aims to facilitate the transition of the lunar ISRU-TEG system from theory to practice, and provide significance guidance for ISRU-TEG system parameter optimization and performance evaluation.