Four-Objective Optimizations of a Single Resonance Energy Selective Electron Refrigerator.

According to the established model of a single resonance energy selective electron refrigerator with heat leakage in the previous literature, this paper performs multi-objective optimization with finite-time thermodynamic theory and NSGA-II algorithm. Cooling load ( R ¯ ), coefficient of performance (ε), ecological function ( E C O ¯ ), and figure of merit ( χ ¯ ) of the ESER are taken as objective functions. Energy boundary (E ′ / k B) and resonance width (Δ E / k B) are regarded as optimization variables and their optimal intervals are obtained. The optimal solutions of quadru-, tri-, bi-, and single-objective optimizations are obtained by selecting the minimum deviation indices with three approaches of TOPSIS, LINMAP, and Shannon Entropy; the smaller the value of deviation index, the better the result. The results show that values of E ′ / k B and Δ E / k B are closely related to the values of the four optimization objectives; selecting the appropriate values of the system can design the system for optimal performance. The deviation indices are 0.0812 with LINMAP and TOPSIS approaches for four-objective optimization ( E C O ¯ − R ¯ − ε − χ ¯ ), while the deviation indices are 0.1085, 0.8455, 0.1865, and 0.1780 for four single-objective optimizations of maximum E C O ¯ , R ¯ , ε , and χ ¯ , respectively. Compared with single-objective optimization, four-objective optimization can better take different optimization objectives into account by choosing appropriate decision-making approaches. The optimal values of E ′ / k B and Δ E / k B range mainly from 12 to 13, and 1.5 to 2.5, respectively, for the four-objective optimization. [ABSTRACT FROM AUTHOR]