A highly efficient heat-driven thermoacoustic cooling system

Thermoacoustic engines and refrigerators operate based on complex interactions and physical effects between working gas and a nearby solid. As an emerging cooling technology, the heat-driven thermoacoustic refrigerator (HDTR) is a promising avenue for its superiorities of eco-friendly working substances and no mechanical moving components. We report an HDTR with bypass configuration, simultaneously synergizing acoustic and energy-flow fields, thus significantly improving the efficiency. We achieve the highest experimental coefficient of performance (COP) of 1.12, along with a cooling power of 2.53 kW at the heating, ambient, and cooling temperatures of 723, 308, and 280 K, respectively. This COP is 2.7 times that of the previously reported best result for HDTRs, to the best of our knowledge, surpassing adsorption refrigerators and competing with absorption refrigerators. These findings highlight the commercial potential of HDTRs in air-conditioning applications and provide guidance for other cooling applications such as the liquification of natural gas and hydrogen.