Differential Pressure Driven Expanders for Cryogenic Refrigerators

Abstract

The invention discloses a differential pressure drive type expansion machine used for a low-temperature refrigeration machine and a preparation method of the differential pressure drive type expansion machine. The differential pressure drive type expansion machine comprises a motor, a gas distribution structure, a gas intake and exhaust base (1), a cylinder assembly (2), a piston assembly, a cold cavity (3) and a cold header heat exchanger (4). Wave springs (5) are fixedly connected between the gas intake and exhaust base and the piston assembly. The space between the gas intake and exhaust base and the piston assembly is divided into an inner cavity (6) and an outer cavity (7) through the wave springs. By means of the piston assembly, the inner cavity communicates with the cold cavity and the cold cavity communicates with the outer cavity. A main gas intake and exhaust port (8) is formed in the portion, located in the inner cavity, of the gas intake and exhaust base. An auxiliary gas intake and exhaust port (9) is formed in the portion, located in the outer cavity, of the gas intake and exhaust base. The differential pressure drive type expansion machine has the beneficial effects that the piston assembly is pushed to conduct expansion working through differential pressure type gas intaking, no crankshaft and connection rod mechanisms are needed, loads of motors are greatly reduced, and therefore the structure is simplified, and reliability is also higher.

Description

technical field [0001] The present invention relates to cryogenic refrigerators, and more particularly to expanders for cryogenic refrigerators. Background technique [0002] With the rapid development of modern information technology, space technology, superconducting electronics, infrared detection, low-temperature biomedicine, gas liquefaction and other industries, especially the promotion and application of low-temperature electronic devices and low-temperature superconducting magnets in various fields, and the development of liquefied natural gas Large-scale use has greatly promoted the development of related low-temperature refrigerator industries. [0003] In the field of small low-temperature refrigerators, the main implementation method is a regenerative heat engine, including G-M refrigerators, G-M pulse tube refrigerators, Stirling refrigerators and Stirling pulse tube refrigerators. G-M refrigerators and G-M pulse tube refrigerators use oil-lubricated compressor...

AI Technical Summary

Problems solved by technology

The main defect of this structure is: the driving force of the piston comes from the motor. When the power of the refrigerator is large, the size of the piston is relatively large, and the driving force of the motor increases accordingly, resulting in a larger volume of the motor and a thicker drive rod. become huge

The disadvantage is that some high-pressure helium cannot be used for refrigeration but is used to drive the ejector movement, and the loss of high-pressure helium is relatively large; the low-pressure helium after expansion and work shares a channel with the high-pressure helium entering the expander , which hinders the reciprocating motion of the ejector and reduces energy utilization

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