Heat exchanger, refrigerating machine and sintered body

Patent metadata

Field	Value
Publication number	US-2021033312-A1
Application number	US-201916975511-A
Country	US
Kind code	A1
Filing date	Feb 25, 2019
Priority date	Feb 26, 2018
Publication date	Feb 4, 2021
Grant date	—

Abstract

A heat exchanger includes: a low temperature side channel through which low temperature liquid helium flows; a high temperature side channel through which high temperature liquid helium flows; and a thermal conduction unit that conducts heat from the high temperature side channel to the low temperature side channel. The thermal conduction unit has a partition member that separates the high temperature side channel and the low temperature side channel from each other and a thermal resistance reduction unit that reduces the thermal resistance between the partition member and the liquid helium. The thermal resistance reduction unit has a porous body having nano-size pores and fine metal particles having higher thermal conductivity than that of the porous body.

First claim

1 . A heat exchanger comprising:
a low temperature side channel through which low temperature liquid helium flows; a high temperature side channel through which high temperature liquid helium flows; and a thermal conduction unit that conducts heat from the high temperature side channel to the low temperature side channel, wherein the thermal conduction unit has: a partition member that separates the high temperature side channel and the low temperature side channel from each other; and a thermal resistance reduction unit that reduces the thermal resistance between the partition member and the liquid helium, and wherein the thermal resistance reduction unit has a porous body having nano-size pores and fine metal particles having higher thermal conductivity than that of the porous body.

2 . The heat exchanger according to claim 1 , wherein the thermal resistance reduction unit is a sintered compact of the porous body and the fine metal particles.

3 . The heat exchanger according to claim 1 , wherein the thermal resistance reduction unit has a thickness in a range of 1 to 1000 μm.

4 . The heat exchanger according to claim 1 , wherein the porous body is a particle in which through holes are formed as the pores.

5 . The heat exchanger according to claim 4 , wherein the through holes have a diameter that allows helium to exist as a liquid inside the through holes.

6 . The heat exchanger according to claim 1 , wherein the porous body has an average pore diameter in a range of 2 to 30 nm.

7 . The heat exchanger according to claim 1 , wherein the porous body are silicate particles whose average particle size is in a range of 50 to 20000 nm.

8 . The heat exchanger according to claim 1 , wherein the specific area of the porous body is 600 m 2 /g or more.

9 . The heat exchanger according to claim 1 , wherein the fine metal particles are silver particles whose average particle size is in a range of 50 to 100000 nm.

10 . A refrigerator comprising:
the heat exchanger according to claim 1 ; a mixing chamber inside which a 3 He dilute phase and a 3 He dense phase are formed and that has an inflow passage for a 3 He liquid to flow into the 3 He dense phase from the high temperature side channel and an outflow passage for a 3 He liquid to flow out to the low temperature side channel from the 3 He dilute phase; a still that has an inflow passage for a 3 He liquid flowing in the low temperature side channel to flow in and selectively separates 3 He as vapor from a liquid mixture of a 4 He liquid and a 3 He liquid; and a cooling path that liquefies the 3 He separated in the still and returns the liquefied 3 He to the high temperature side channel.

11 . A sintered compact of a porous body having nano-size pores and fine metal particles having higher thermal conductivity than that of the porous body,
wherein 4 He and 3 He are adsorbed inside the pores.

Assignees

• National Univ Corporation Tokai National Higher Education And Research System

Inventors

• Wada Nobuo
• Matsushita Taku
• Hieda Mitsunori

Classifications

• F28F21/02

  of carbon, e.g. graphite · CPC title

• F28F13/003 Primary

  by using permeable mass, perforated or porous materials (F28F13/18 takes precedence) · CPC title

• F28F21/08

  of metal · CPC title

• F28F2255/20

  with nanostructures · CPC title

• F28F3/06

  the means being attachable to the element · CPC title