Structure and operation parameter optimization and performance improvement of thermoelectric generator in outer space

Thermoelectric generator (TEG) plays an important role in waste heat utilization and clean power generation. However, the relationship between the structure and the safety temperature of TEG is ignored, and no research has been reported about the application of TEG in outer space. In this study, a three-dimension thermal-electrical–mechanical coupling model of TEG operating in outer space is established, and its electrical and mechanical performance is investigated. Firstly, three typical cases of TEG with different structure and operating temperature difference are compared, and the advantages (high efficiency and power density) and problem (high thermal stress) faced of TEG applied in outer space are illustrated. Then, the effects of structure and operation parameters of TEG on electrical and mechanical performance are analyzed. The design variables for TEG are determined and their interaction relationships is provided. In particular, a phenomenon that the copper strips tend to exceed failure limit more than other components is clearly pointed out. Finally, optimization on structure and operation parameters is performed, and the optimal case with a = 2.52 mm, h = 1.06 mm, R_L = 0.010 Ω and T_c = 214.11 K is obtained and recommended. The optimal case has the maximum power density 175.73 W/kg, and its efficiency still has 5.17% ranking the third highest value among the comparison cases. The results in this research can provide a reference for the design of TEG with applications in outer space.