Analysis of a Coaxial, Compact Thermoacoustic Heat-Pump

An analytical approach to describe the behaviour of a compact thermoacoustic stack-based or regenerator-based heat-pump driven by two acoustic sources has been presented in a previous paper [Acta Acustica united with Acustica 97 (2011) 926-932]. It appears to be suitable for fitting adjustable parameters to achieve optimal heat transfer or temperature gradient, even COP. This model has been used to design such thermoacoustic refrigerators, which involve compactness and flexibility. The predicted characteristics are compared with some experimental results in this paper. Then performance of this small scale thermoacoustic device is compared with the one obtained with standing or travelling wave devices having similar stack/regenerator. Slightly higher efficiency than in the standing wave system is found, whereas the comparison with the coaxial travelling wave configuration gives slightly lower efficiency, yet at much smaller size.