A Heat-driven thermoacoustic cooler capable of reaching liquid nitrogen temperature

This article introduces a heat-driven thermoacoustic cooler capable of reaching liquid nitrogen temperature with no moving parts. The thermoacoustic cooler consists of a traveling wave thermoacoustic prime mover and a pulse tube cooler. By using a tapered resonance tube, the prime mover can provide a pressure ratio higher than 1.26. By using a long thin tube, a reservoir is no longer needed in the pulse tube cooler. After preliminary optimizations, the lowest temperature reaches 68.8 K. This result shows the potential to achieve cryogenic temperatures lower than 70 K by applying thermoacoustic technology, which is simply realized through combinations of tubes and solid materials without the need of any moving parts. (c) 2005 American Institute of Physics.