Cryogenic refrigerator

Patent metadata

Field	Value
Publication number	US-2016123631-A1
Application number	US-201514921017-A
Country	US
Kind code	A1
Filing date	Oct 23, 2015
Priority date	Oct 29, 2014
Publication date	May 5, 2016
Grant date	—

Abstract

In a cryogenic refrigerator, a displacer defines an internal space, and circulates a working fluid in the internal space. A cylinder houses the displacer such as to enable it to reciprocate, and, at an interval from the bottom side of the displacer, forms an expansion space for the working fluid. A cooling stage is provided along an outer circumferential and bottom portion of the cylinder, in a location corresponding to the expansion space. A heat exchanger is arranged inside the expansion space and is thermally connected to the cooling stage. An end portion of the displacer on its expansion-space side has an opening that serves as an entry/exit port between the internal space and the expansion space for the working fluid. A working-fluid flow channel connects the internal space and the expansion space via the heat exchanger.

First claim

What is claimed is:

1 . A cryogenic refrigerator comprising:
a displacer defining an internal space, the displacer for circulating a working fluid in the internal space; a cylinder housing the displacer such as to enable the displacer to reciprocate, and forming, at an interval from a bottom surface of the displacer, an expansion space for the working fluid; a cooling stage provided along an outer circumferential and bottom portion of the cylinder, in a location corresponding to the expansion space; a heat exchanger arranged inside the expansion space, and thermally connected to the cooling stage; an opening furnished in an expansion-space-ward end portion of the displacer, the opening constituting an entry/exit port between the internal space and the expansion space for the working fluid; and a working-fluid flow channel connecting the internal space and the expansion space via the heat exchanger.

2 . The cryogenic refrigerator according to claim 1 , further comprising:
a receiver provided in a bottom portion of the expansion space, for receiving an expansion-space-ward end portion of the flow channel such as to block circulation of the working fluid at least when the displacer is at bottom dead center.

3 . The cryogenic refrigerator according to claim 2 , wherein the receiver is of depth-wise dimension less than or equal to half the displacer's stroke length.

4 . The cryogenic refrigerator according to claim 1 , wherein the heat exchanger is either a wire-mesh assembly, or slits.

5 . The cryogenic refrigerator according to claim 1 , wherein a clearance communicating with the opening is provided between a sidewall of the displacer and an inner wall of the cylinder.

6 . The cryogenic refrigerator according to claim 1 , wherein the flow channel includes a conduit formed in a bottom portion of the displacer, protruding into the expansion space.

Assignees

• Sumitomo Heavy Industries

Inventors

• Xu Mingyao

Classifications

• F25B9/14 Primary

  characterised by the cycle used, e.g. Stirling cycle · CPC title

• F25B2309/1418

  Pulse-tube cycles with valves in gas supply and return lines · CPC title

• F25B2309/1412

  Pulse-tube cycles characterised by heat exchanger details · CPC title

• F25B2309/1406

  Pulse-tube cycles with pulse tube in co-axial or concentric geometrical arrangements · CPC title

• F25B2309/003

  characterised by construction or composition of the regenerator · CPC title