The possibility of scaling-down thermoacoustic refrigerators is theor. investigated. Standing-wave systems are considered as well as traveling-wave. In the former case, a ref. system is taken that consists of a resonator tube (50 cm) with a closed end and a PVC stack (length 5 cm). Helium is used at a mean pressure of 10 bar and an amplitude of 1 bar. The resulting operating frequency is 1 kHz. The variation of the performance of the refrigerator when scaled down in size is computed under the prerequisites that the temp. drop over the stack or the energy flux or its d. are fixed. The anal. results show that there is a limitation in scaling-down a standing-wave thermoacoustic refrigerator due to heat conduction. Similar scaling trends are considered in traveling-wave refrigerators. The traveling-wave ref. system consists of a feedback inertance tube of 0.567 m long, inside diam. 78 mm, a compliance vol. of 2830 cm3 and a 24 cm thermal buffer tube. The regenerator is sandwiched between two heat exchangers. The system is operated at 125 Hz and filled with 30 bar helium gas. Again, the thermal conductance forms a practical limitation in down-scaling.
|Title of host publication||Transactions of the Cryogenic Engineering Conference (CEC 2007), 16-20 July 2007 Chattanooga, Tennessee|
|Place of Publication||Melville, NY|
|Publisher||American Institute of Physics|
|Publication status||Published - 2008|
|Name||AIP Conference Proceedings|
|Name||Advances in cryogenic engineering|