Nowadays, air refrigerator possesses some potential for applications. Based on finite-time thermodynamics, an irreversible simple Brayton refrigeration cycle is taken as research object herein. Firstly, efficient cooling load ( \(\Omega\) )(product of cooling load ( \(R\) ) and coefficient of performance ( \(\varepsilon\) )) is selected as optimization objective. The relationship among \(\Omega\) and pressure ratio ( \(\pi\) ) and heat conductance distribution ( \(u\) ) is obtained by numerical calculations. Secondly, taking \(\pi\) and \(u\) as optimal variables, and taking \(\varepsilon\) , \(R\) , ecological function, \(\Omega\) and their combinations as optimization objectives, and multi-objective optimizations are performed via NASG-II. Totally fifteen optimization problems, including one quadruple-objective, four triple-objectives, six double-objectives and four single-objectives optimization problems, are solved. Results show that optimization results of \(\Omega\) ensure coordination between \(R\) and \(\varepsilon\) . Three decision-making strategies of TOPSIS, LINMAP and Shannon entropy are utilized to ascertain final solutions, and TOPSIS and LINMAP decision-making strategies have the best results when quadruple-objective optimizations are performed. The solution selected by LINMAP decision-making strategy is the best when double-objective optimization of \(\varepsilon\) and ecological function is performed. Multi-objective optimization can solve the problem of conflicting optimization results among multiple optimization objectives. It can find the best scheme for improving the performance of refrigerator, which can achieve the best trade-off of performance objectives.
