Heat and mass transfer component comprising a lubricant-impregnated surface

Patent metadata

Field	Value
Publication number	US-11525641-B2
Application number	US-202016854014-A
Country	US
Kind code	B2
Filing date	Apr 21, 2020
Priority date	Apr 22, 2019
Publication date	Dec 13, 2022
Grant date	Dec 13, 2022

Abstract

A heat and mass transfer component comprises a lubricant-impregnated surface including hydrophobic surface features, which comprise nanostructured surface protrusions having a hydrophobic species attached thereto. The hydrophobic surface features are impregnated with a fluorinated lubricant having a viscosity in a range from about 400 mPa·s to about 6000 mPa·s. A method of fabricating a lubricant-impregnated surface on a heat and mass transfer component comprises: cleaning a thermally conductive substrate to form a cleaned substrate; exposing the cleaned substrate to a hot water or hot alkaline solution to form a thermally conductive substrate having nanostructured surface protrusions; depositing a hydrophobic species on the nanostructured surface protrusions to form hydrophobic surface features; and coating the hydrophobic surface features with a fluorinated lubricant having a viscosity in a range from 400 mPa·s to 6000 mPa·s. The heat and mass transfer component may exhibit a substantial increase in heat transfer coefficient during hydrocarbon condensation.

First claim

The invention claimed is:

1. A heat and mass transfer component comprising:
a lubricant-impregnated surface including:
hydrophobic surface features comprising nanostructured surface protrusions having a hydrophobic species attached thereto; and
a fluorinated lubricant having a viscosity in a range from about 400 mPa·s to about 6000 mPa·s impregnating the hydrophobic surface features.

2. The heat and mass transfer component of claim 1 being part or all of a heat exchanger.

3. The heat and mass transfer component of claim 1 being part or all of a distillation column.

4. The heat and mass transfer component of claim 1 , wherein, when a working fluid having a surface tension in a range from about 15 mN/m to about 30 mN/m contacts the lubricant-impregnated surface, dropwise condensation of the working fluid occurs, thereby facilitating heat transfer from the component.

5. The heat and mass transfer component of claim 4 , wherein the lubricant-impregnated surface is configured to sustain drop-wise condensation for a period of at least 1000 hours, the lubricant-impregnated surface thereby exhibiting long-term durability.

6. The heat and mass transfer component of claim 1 , wherein, when a working fluid comprising dissolved, suspended, entrained, crystallized and/or precipitated solids contacts the lubricant-impregnated surface, deposition of solids on the lubricant-impregnated surface is inhibited, the component thereby resisting fouling.

7. The heat and mass transfer component of claim 6 , wherein the lubricant-impregnated surface is configured to inhibit deposition of solids for at least 1000 hours, the lubricant-impregnated surface thereby exhibiting long-term durability.

8. The heat and mass transfer component of claim 1 , wherein the thermally conductive substrate comprises a metal selected from the group consisting of Cu, Al, Fe, and Ti, and
wherein the nanostructured surface protrusions comprise an oxidized metal selected from the group consisting of copper oxide, aluminum oxide, iron oxide, and titanium dioxide.

9. The heat and mass transfer component of claim 1 , wherein the nanostructured surface protrusions exhibit a roughness factor r in a range from about 5 to 50.

10. The heat and mass transfer component of claim 1 , wherein the hydrophobic species comprises a silane.

11. The heat and mass transfer component of claim 1 , wherein the fluorinated lubricant comprises a perfluoropolyether (PFPE) oil.

12. The heat and mass transfer component of claim 1 , wherein the fluorinated lubricant comprises:
a liquid density p in a range from about 1800 kg/m 3 to about 2000 kg/m 3 ;
a low surface tension γ in a range from about 10 mN/m to about 30 mN/m; and
a vapor pressure P vap no greater than about 1×10 −7 kPa.

13. A method of using the heat and mass transfer component of claim 1 , the method comprising:
exposing the lubricant-impregnated surface to a working fluid having a surface tension in a range from about 15 mN/m to about 30 mN/m; and
during the exposure, obtaining dropwise condensation of the working fluid on the lubricant-impregnated surface, wherein, due to the dropwise condensation, the heat and mass transfer component exhibits a steady state condensation heat transfer coefficient of at least about 6 kW/m 2 K.

14. The method of claim 13 , wherein the steady state condensation heat transfer coefficient is at least about 9 kW/m 2 K.

15. The method of claim 13 , wherein the exposure to the working fluid occurs for a period of at least 1000 hours.

16. The method of claim 13 , wherein the working fluid further comprises dissolved, suspended, entrained, crystallized and/or precipitated solids, and
wherein, during the exposure, deposition of solids on the lubricant-impregnated surface is inhibited, the heat and mass transfer component thereby resisting fouling.

17. The method of claim 13 , wherein the working fluid comprises an alcohol and/or a hydrocarbon.

18. The method of claim 17 , wherein the working fluid comprises a mixture of hydrocarbons or a purified hydrocarbon.

19. The method of claim 17 , wherein the working fluid is selected from the group consisting of: ethanol, isopropyl alcohol, pentane, hexane, xylene, and toluene.

20. A method of fabricating lubricant-impregnated surface on a heat and mass transfer component, the method comprising:
cleaning a thermally conductive substrate to form a cleaned substrate;
exposing the cleaned substrate to a hot water or hot alkaline solution to form a thermally conductive substrate having nanostructured surface protrusions;
depositing a hydrophobic species on the nanostructured surface protrusions to form hydrophobic surface features; and
coating the hydrophobic surface features with a fluorinated lubricant having a viscosity in a range from 400 mPa·s to 6000 mPa·s, thereby forming a lubricant-impregnated surface on a heat and mass transfer component.

Assignees

• Univ Illinois

Inventors

• Miljkovic Nenad
• Sett Soumyadip
• Barac George
• Bolton Leslie W

Classifications

• C10N2050/06

  Gaseous phase, at least during working conditions · CPC title

• C10N2020/09

  Characteristics associated with water · CPC title

• C10M107/38 Primary

  containing halogen · CPC title

• C10N2080/00

  Special pretreatment of the material to be lubricated, e.g. phosphatising or chromatising of a metal · CPC title

• C10N2050/025

  in the form of films or sheets · CPC title