Sustainable heat-driven sound cooler with super-high efficiency

Sustainable cooling technologies with high efficiency are increasingly vital in modern life. Characterized by eco-friendly working substances and no mechanical moving components, the heat-driven thermoacoustic refrigerator (HDTR) makes it a really sustainable choice. However, its practical application has been hindered by its relatively low efficiency. This work reports a breakthrough in thermally-powered sound cooling technology: a super-efficient HDTR. The system incorporates an innovative configuration, ensuring efficient acoustic power matching between the engine and cooler units at high heating temperatures, thereby significantly boosting efficiency. Our experimental findings are exhilarating: the HDTR achieves an unprecedented coefficient of performance (COP) of 1.34 at heating, ambient, and cooling temperatures of 550 °C, 35 °C, and 7 °C, respectively, along with a cooling power of 2.37 kW. To the best of our knowledge, under approximate temperature spans, this COP surprisingly increases by 240% compared to the best result previously reported for HDTRs without using the novel configuration. These results represent a significant advancement in HDTR technology, showing a tremendous potential of the HDTR as an emerging, sustainable cooling technology, particularly for heat-driven room-temperature refrigeration applications.