Study of thermoacoustic refrigeration with variations of resonator length and stack space

Thermoacoustic refrigeration is a refrigeration method that uses acoustic wave driver and gas fluid instead of refrigerant as working fluid. In this paper, the development of a small scale refrigeration system based on thernoacoustic principle is presented. The main apparatus is a resonator, which is designed with variations of resonator length and stack space. The experiment shows the appearance of the temperature gradient along the apparatus during the resonance. The experimental results showed that the combination of 75 cm, 70 cm, and 60 cm resonator lengths and 1 mm, 0, 32 mm and 0, 25 mm stack space showed the thermoacoustic phenomenon as predicted, while other variations did not. The calculation of acoustic power and COPcn showed that air is not a suitable working fluid. Therefore gas with less Prandtl Number, such as inert gas, is recommended as working fluid for better performance.