Performance of a small, low‐lift regenerator‐based thermoacoustic refrigerator

A regenerator‐based thermoacoustic refrigerator [Swift, Gardner, and Backhaus, ‘‘Acoustic recovery of lost power in pulse tube refrigerators,’’ J. Acoust. Soc. Am. 105(2), 711 (1999)] has been constructed. It is capable of moving about 5 W across a 40<th>°C temperature span. The machine operates with air at atmospheric pressure and is driven by an off‐the‐shelf electro‐dynamic loudspeaker capable of producing peak‐to‐mean pressure ratios up to 12%. The thermal core of this research device contains an exhaust‐side shell and tube heat exchanger (with water as the secondary heat transfer fluid), a regenerator made of 88 annular stainless‐steel screens, and a constantan wire electrical heater that applies a measurable heat load to the cold side of the regenerator. An annular latex diaphragm is placed over the cold side of the regenerator to stop time‐averaged mass flow through the regenerator and insulate the cold side [Gedeon, ‘‘DC Gas Flows in Stirling and Pulse Tube Cryocoolers,’’ in Cryocoolers 9, edited by R. G. Ross (Plenum, New York, 1997)]. Detailed measurements of heat load, temperature span, and exhaust heat flux will be presented and compared to DeltaE. [Work supported by ONR.]