|
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 |