Porous layer

• US 9,103,607 B2
• Filed: 03/02/2007
• Issued: 08/11/2015
• Est. Priority Date: 03/03/2006
• Status: Expired due to Fees

• Current Assignee: Danfoss A/S
• Original Assignee: Micro Delta T AB
• Inventors: Furberg, Richard, Li, Shanghua, Muhammed, Mamoun, Palm, Bjrn, Toprak, Muhammet
• Primary Examiner(s): Jules, Frantz
• Assistant Examiner(s): TRPISOVSKY, JOSEPH F
• Application Number:
  US12/224,707
• Publication Number:
  US 20100044018A1
• Time in Patent Office: 3,084 Days
• Field of Search: 165/133, 165/146, 165/911, 428/613, 205/111, 205/112, 427/248.1
• US Class Current: 1/1
• CPC Class Codes: C25D 5/003 Electroplating using gases, e.g. pressure influence
• CPC Class Codes: C25D 5/50 by heat-treatment
• CPC Class Codes: C25D 5/605 Surface topography of the layers, e.g. rough, dendritic or nodular layers
• CPC Class Codes: C25D 5/617 Crystalline layers
• CPC Class Codes: C25D 5/623 Porosity of the layers
• CPC Class Codes: C25D 7/00 Electroplating characterised by the article coated
• CPC Class Codes: F28F 13/187 especially adapted for evaporator surfaces or condenser surfaces, e.g. with nucleation sites
• CPC Class Codes: F28F 2255/20 with nanostructures
• CPC Class Codes: Y10T 428/12479 Porous [e.g., foamed, spongy, cracked, etc.]
• CPC Class Codes: Y10T 428/26 Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension

Abstract

Heat exchange device with a boiling surface comprising a porous surface layer arranged on a solid substrate, the porous surface layer comprises a porous wall structure defining and separating macro-pores that are interconnected in the general direction normal to the surface of the substrate and have a diameter greater than 5 μm and less than 1000 μm wherein the diameter of the pores gradually increases with distance from the substrate wherein the porous wall structure is a continuous branched structure.

Claims

1. A method for forming a surface layer on a substrate, comprising the steps of:

providing a substrate having a copper surface cathode;

depositing a surface layer on the surface of the substrate by electrodeposition from a copper anode in a solution of copper sulphate and 1.5M sulpheric acid, the surface layer comprising a porous wall structure defining and separating macro-pores that are interconnected in the general direction normal to the surface of the substrate and that have a diameter greater than 5 μ

m and less than 1000 μ

m, wherein the diameter of the pores gradually increases with distance from the substrate, and wherein the porous wall structure comprises dendritically ordered copper nanoparticles; and

modifying the porous wall structure to a continuous branched structure formed of the dendritically ordered copper nanoparticles that have been modified by annealing at 500°

C. for 5 hours to increase a grain size of the nanoparticles and reduce a boundary effect of the nanoparticles,

wherein a boiling surface comprising the surface layer on the substrate maintains stable performance for over 80 hours in a pool of saturated R134a at a pressure of 4 bar and at a heat flux between 0.1 W/cm² and 10 W/cm² so as to have a surface superheat temperature difference of less than 0.3°

C. at a heat flux of 1 W/cm² and a surface superheat temperature difference of less than 1.5°

C. at a heat flux of 10 W/cm².

2. The method according to claim 1, wherein the step of modifying the porous wall structure comprises controlled deposition of a 1 nm to 10 μ

m solid copper layer on the porous wall structure.

3. The method according to claim 1, comprising the step of depositing via controlled deposition a 1 nm to 10 μ

m solid copper layer on the substrate surface prior to the step of depositing the surface layer.

4. The method according to claim 3, wherein the deposition of the solid copper layer is performed by electrodeposition or gas phase deposition.

5. The method according to claim 1, wherein the surface layer is deposited by a controlled electrodeposition process generating gas bubbles that define the macro-pores, thereby depositing the material on the substrate to form the surface layer with both regularly spaced and shaped, micron-sized pores and the wall structure of dendritically ordered copper nanoparticles.

6. The method according to claim 3, wherein the surface layer is deposited by a controlled gas phase deposition process generating gas bubbles that define the macro-pores, thereby depositing the material on the substrate to form the surface layer with both regularly spaced and shaped, micron-sized pores and the wall structure of dendritically ordered copper nanoparticles.