Tapered pulse tube for pulse tube refrigerators
AssigneeThe Regent of the University of California
InventorsGregory W. Swift, Jeffrey R. Olson
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Abstract
Thermal insulation of the pulse tube in a pulse-tube refrigerator is maintained by optimally varying the radius of the pulse tube to suppress convective heat loss from mass flux streaming in the pulse tube. A simple cone with an optimum taper angle will often provide sufficient improvement. Alternatively, the pulse tube radius r as a function of axial position x can be shaped with r(x) such that streaming is optimally suppressed at each x.
Claims8
A pulse tube refrigerator using an oscillating working fluid to transfer heat within the refrigerator, including:
- a regenerator containing the oscillating working fluid and having a hot heat exchanger on a first side and a cold heat exchanger on a second side to provide refrigeration;
- a second hot heat exchanger connected to an orifice and compliance for adjusting parameters of the oscillating working fluid;
- wherein the improvement comprises
- a tapered pulse tube connecting the cold heat exchanger and the second hot heat exchanger and having a cross-sectional area variation effective axially between the cold heat exchanger and the second hot heat exchanger to minimize heat loss through streaming-driven convection of the oscillating working fluid to thermally isolate the cold heat exchanger from the hot heat exchanger.
A pulse tube for use in a pulse tube refrigerator having a cross-sectional area variation effective to minimize heat loss through streaming-driven convection within the pulse tube.
Dependencies are inferred from the claim text.