Thermoacoustic Refrigeration

A sound wave consists of oscillations in pressure, temperature, and displacement. Although the temperature oscillations are small, research during the past two decades has shown that this "thermoacoustic" effect can be harnessed to produce powerful, reasonably efficient heat engines, including heat pumps, and refrigerators. Thermoacoustic engines typically have no moving parts; at most, there is a single oscillating part (such as a loudspeaker) with no sliding seals. Thus, these engines have the potential to be both simple and reliable. Research by Greg Swift at Los Alamos National Laboratory on the thermodynamics of the thermoacoustic process has led to the development of prototype refrigerators with cooling powers up to tens of watts, and prototype engines with efficiencies approaching those of conventional engines. The research has spawned collaborative efforts that have resulted in advances in the theory, design, and construction of thermoacoustic devices.

Scientific Impact: Los Alamos' leadership in both the scientific and technological aspects of thermoacoustics since the mid-1980s has generated a sizeable academic research community around the world. The first international workshop on thermoacoustics will be held in 2001.

Social Impact: Thermoacoustic energy conversion (including conversion of heat to acoustic power, acoustic power to refrigeration, and acoustic power to mixture separation) is reasonably efficient and should be inexpensive and reliable in mass production. Efforts are under way to develop a natural-gas liquefier for use in remote locations, a residential co-generation system to produce both electricity and gas heat, an electric generator for deep-space probes, and a water chiller for use on submarines.

Reference: S. Backhaus and G.W. Swift. "A thermoacoustic-Stirling heat engine." Nature, 399:335-338, 1999.

G. W. Swift. "Thermoacoustic engines and refrigerators." Physics Today, pages 22-28, July 1995.

G. W. Swift. "Thermoacoustic engines." J. Acoust. Soc. Am., 84:1145-1180, 1988.

URL: http://www.lanl.gov/projects/thermoacoustics/

Technical Contact: Don Freeburn, Office of Basic Energy Sciences, 301-903-3156

Press Contact: Jeff Sherwood, DOE Office of Public Affairs, 202-586-5806

SC-Funding Office: Office of Basic Energy Sciences