Performance analysis and structure optimization for concentrated photovoltaic-phase change material-thermoelectric system in space conditions

High-efficient thermal management is urgently needed for concentrated photovoltaic-thermoelectric hybrid system due to the high heat flux. In present paper, a three-dimensional model for the hybrid system in outer space conditions was established by coupling phase change temperature control and radiation heat sink technologies to find the propriate thermal management scheme. Firstly, the three shortcomings in the typical hybrid system were proposed and their adverse effects on efficiency were elucidated. Then, a heat transfer pillar for temperature control unit and a newly designed circular fins for heat sink were designed. The effects of structure parameters on power generation performance were investigated, and the interaction between temperature control unit and heat sink were discussed. The results show that the hybrid systems with the newly designed heat transfer pillar and circular fins have higher efficiency. After that, a united structure optimization by artificial neural network-multi-objective genetic algorithm was performed to solve the interaction and to balance the electrical efficiency and power density of hybrid system. The comprehensive power generation performance of hybrid system can be further improved after the optimization. The system with PCM thickness d_PCM = 6.33 mm, heat transfer pillar width a = 18.19 mm, fin length L = 49.99 mm and fin radius R = 50 mm, has the maximum average total efficiency (31.83%, 2.98% higher than the typical system); the system with d_PCM = 3.02 mm, a = 10.05 mm, L = 47.03 mm and R = 25.86 mm, has the maximum average power density (36.97 W/kg, 15.78% higher than the typical system).