Bi-directional porous media phase change heat exchanger

Patent metadata

Field	Value
Publication number	US-2020217587-A1
Application number	US-201414227083-A
Country	US
Kind code	A1
Filing date	Mar 27, 2014
Priority date	Mar 27, 2014
Publication date	Jul 9, 2020
Grant date	—

Abstract

Heat exchange structure. A hydrophilic, thermally conductive porous medium includes nanostructures formed substantially uniformly throughout the porous medium providing a balance of capillary and viscous forces to self-regulate a liquid-vapor contact line. A suitable porous medium is copper. A method for making the structure is also disclosed.

First claim

1 . Heat exchange structure comprising:
a hydrophobic nonporous region adjacent to a hydrophilic porous media evaporator, the hydrophilic porous media evaporator being a thermally conductive porous medium including nanostructures, the nanostructures both in central portions of the porous medium as well as on surfaces of the porous medium configured to provide a balance of capillary and viscous forces to self-regulate a liquid-vapor contact line such that active throttling is not required and the porous medium remain hydrophilic in the presence of organic contaminates, and a hydrophobic cap layer directly over the thermally conductive porous medium.

2 . The structure of claim 1 wherein the porous medium is copper.

3 . The structure of claim 1 wherein the hydrophobic cap layer includes butadiene-styrene, silicone or teflon.

4 . Method for making a heat exchange structure comprising:
anodizing a porous copper structure in an oxidizing alkaline medium at approximately 75° C., the oxidizing alkaline medium comprising sodium chlorite, sodium hydroxide, and sodium phosphate tribasic dodecahydrate and deionized water, whereby nanostructures are formed throughout the porous copper structure.

5 . The method of claim 4 wherein the solution is (75:1:5:100) weight percent.

6 . The method of claim 4 further including holding the copper porous medium at approximately 1.5 volts relative to a counter electrode in pulses of approximately 20 seconds duration with approximately 10 seconds between pulses to improve uniformity of nanostructure growth.

7 . The structure of claim 1 disposed on the surface of a finned tube.

8 . The structure of claim 1 disposed on the surface of a flat plate.

Assignees

• Massachusetts Inst Technology

Inventors

• Mckay Ian Salmon
• Narayanan Shankar
• Wang Evelyn N

Classifications

• Y02E60/14

  Thermal energy storage · CPC title

• F28F2245/02

  hydrophilic · CPC title

• F28F13/182

  especially adapted for evaporator or condenser surfaces (F28F13/187 takes precedence) · CPC title

• F28D1/03

  with plate-like or laminated conduits {(stacked plates having one or more openings therein to form tubular heat-exchange passages F28F3/086)} · CPC title

• F28D1/04

  with tubular conduits {(F28D1/0246 takes precedence)} · CPC title