Design and Analysis of Thermoacoustic Refrigerators Using Air as Working Substance

In this paper, the design of 50 W thermoacoustic refrigerators operating with air as working substance at 10 bar pressure and 3 drive ratio for a temperature difference of 28 K is described. The design strategies discussed in this paper help in design and development of low cost thermoacoustic coolers compared to helium as the working substance. The design and optimization of spiral stack and heat exchangers, and the promising 0.2λ and 0.15λ resonator design with taper and divergent section with hemispherical end are discussed. The surface area, volume, length and power density of the hemispherical end design with air as working substance is found better compared to the published 10 and 50 W coolers using helium as the working substance. The theoretical design results are validated using DeltaEC software simulation results. The DeltaEC predicts 51.4 improvement in COP (1.273) at the cold heat exchanger temperature of -2.7°C with air as working substance for the 50W 0.15λTDH resonator design compared to the published 50W 0.25λTDH resonator design with helium as working substance. © 2019 World Scientific Publishing Company