Single-objective Optimization for Stack Unit of Standing Wave Thermoacoustic Refrigerator through Particle Swarm Optimization Method

Abstract

Thermoacoustic refrigeration is being regarded as a promising alternative technology with the absence of harmful refrigerants including no or few moving parts, providing the ability to use low grade energy sources for energy conservation. However, the performances of thermoacoustic refrigerators are still low compared to their counterparts, the conventional vapor-compression ones due to involving multi-scale, even multi-field thermo-physical matters with electromagnetic or piezoelectric actuators. Therefore, design optimization of such systems has become quite necessary and significant for achieving competitive performances. In the present study, particle swarm optimization (PSO) is introduced as an intelligent method for such optimization. The stack unit as the key element responsible for thermoacoustic cooling effect, is focused in our first attempt. Coefficient of performance (COP) of the stack unit would be considered as the single-objective function to be maximized under some constraints including stack length, stack center position, blockage ratio and drive ratio. The present study had shown the capability and significant advantages of PSO through showing better optimal result compared to published literature ones. In addition, some considerations for optimization criteria were discussed. Based on this study, PSO could be possibly a favorable intelligent method suitable to the design optimization of thermoacoustic refrigerators or heat engines and their key components effectively.