Experimental study of a thermoacoustically-driven traveling wave thermoacoustic refrigerator

New configurations of traveling wave thermoacoustic refrigerators driven by a traveling wave thermoacoustic engine were introduced and tested in this paper. First, the performance of the refrigerator with different-diameter inertance tubes was investigated experimentally. Then, investigation of substituting a flexible membrane attached to inertial mass for inertance tube was tested. The experimental results show that the substitution could improve the efficiency of the system and lead to a larger cooling power. So far, using helium gas as the working gas, the system could provide 340 W cooling power at the temperature of −20 °C with working frequency of 57 Hz and average pressure of 3.0 MPa. The total COP, i.e., cooling power divided by heating power, is 0.16.

Research highlights
► We introduced and tested new configurations of traveling-wave thermoacoustic refrigerators (TWTR) in this research.
► The new configuration can make the TWTR more compact and more efficient.
► We showed experimentally that the TWTR with the lumped inertial mass as the phase shifter gave better cooling performance.
► In the experiment, the cooling powers of about 340 W and 469 W at −20 °C and 0 °C were achieved, and the corresponding COPs were 0.16 and 0.216, respectively. The experimental result is among the best result reported so far for the thermoacoustically-driven TWTR.