Solid state cryocooler

Abstract

A cryocooler is disclosed which includes a reservoir (11), an electrochemical cell or proton conductive membrane (PCM) compressor (12) coupled to a source of AC current, and a gas expander in the form of a pulse tube expander module (13). The compressor (12) includes a proton conductive membrane (17) positioned between a pair of electrically conductive electrodes (18) and (19). The pulse tube expander module 13 includes a regenerator (21), a pulse tube (22), and in inertance tube (23). The regenerator (21) has a heat rejection part or aftercooler (25) and a cooling part or cold heat exchanger (26). The pulse tube (22) includes a heat rejection portion or hot heat exchanger (27).

Description

TECHNICAL FIELD [0001] This invention relates generally to cryocoolers, and more particularly to a solid state cryocooler. BACKGROUND OF THE INVENTION [0002] Since a cryocooler using a Stirling cycle can obtain cryogenic temperatures by repeatedly compressing and expanding a working gas, it has become widely used in cooling operations, such as for cooling of superconducting elements, refining and separation of gases, infrared ray sensors, or the like. [0003] The operation principle of a Stirling cryocooler, using this Stirling cycle, relates to the rising and falling of a compression piston and a displacer in accordance with a refrigeration cycle. [0004] A Stirling cryocooler typically includes a compressor having a compression piston, a regenerator having a regenerating agent, a displacer forming an expansion chamber and a compression chamber, a cooling part formed between the expansion chamber and the regenerator, and a heat rejection part formed around the compression chamber. A ...

AI Technical Summary

Problems solved by technology

The stressing lifetime and reliability requirements result in tight tolerances, labor intensive assembly procedures, and costly materials.

The vibration output requirement also contributes to the design complexity of the cryocooler and necessitates expensive control electronics that mitigate the vibration output through closed-loop control of the input current waveform.

All of these measures are costly to implement.

Furthermore, even with the progress made to date on vibration control, jitter can still be an issue for sensor designers.

In short, generation of the pressure wave through a mechanical piston introduces practical limits with respect to vibration output, reliability, lifetime, and packaging, and the industry is collectively approaching those limits.

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