Traveling-wave thermoacoustic refrigerator for room temperature application

•Drawbacks of single-stage thermoacoustic refrigerator at room temperature is revealed•Multi-stage thermoacoustic refrigerator is proposed to enhance cooling performance•A cooling power of 4.63 kW with COP of 3.08 is obtained for a three-stage system As a new type of refrigeration technology, the traveling-wave thermoacoustic refrigerator offers advantages that include high efficiency, reliability and environmental friendliness. To date, because of problems such as low power utilization and high power recovery losses, traveling-wave thermoacoustic refrigerators for use in room temperature applications have not been widely studied. In this paper, following an investigation of the traditional single-stage traveling-wave thermoacoustic refrigerator, a multi-stage traveling-wave thermoacoustic refrigerator is proposed and the working mechanism of this refrigerator is studied numerically using SAGE software. The calculation results show that the proposed multi-stage traveling-wave thermoacoustic refrigerator can enhance the utilization of the input acoustic work effectively, thereby improving the cooling power of the refrigerator with high cooling efficiency. As a result, the cooling power increases from 2.17 kW for a single-stage refrigerator to 6.42 kW for a seven-stage refrigerator, while the acoustic work utilization rate increases from 0.26 to 0.82, and the coefficient of performance changes from 2.60 to 3.19. The calculation results also indicate that three to five stages may be most suitable for the multi-stage traveling-wave thermoacoustic refrigerator when working within the temperature range of interest here by striking a balance between cooling efficiency and cooling power.