Method for providing refrigeration using capillary pumped liquid

• US 20050005617A1
• Filed: 07/10/2003
• Published: 01/13/2005
• Est. Priority Date: 07/10/2003
• Status: Active Grant

• Current Assignee: Praxair Technology Incorporated (Linde Plc)
• Original Assignee: Praxair Technology Incorporated (Linde Plc)
• Inventors: Jibb, Richard J.
• Granted Patent: US 6,865,897 B2
• Time in Patent Office: Days
• US Class Current: 62/99
• CPC Class Codes: F25B 23/006 boiling cooling systems
• CPC Class Codes: F25B 2309/1424 Pulse tubes with basic schematic including an orifice and a reservoir
• CPC Class Codes: F25B 2400/06 Several compression cycles arranged in parallel
• CPC Class Codes: F25B 2400/16 Receivers
• CPC Class Codes: F25B 25/005 using primary and secondary systems
• CPC Class Codes: F25B 9/14 characterised by the cycle used, e.g. Stirling cycle
• CPC Class Codes: F25B 9/145 pulse-tube cycle
• CPC Class Codes: F28D 15/043 forming loops, e.g. capillary pumped loops
• CPC Class Codes: H05K 7/20372 Cryogenic cooling; Nitrogen liquid cooling

Abstract

A method for providing refrigeration to a refrigeration load such as superconducting equipment while reducing or eliminating potential two phase instability oscillations, wherein refrigeration condenses working fluid which is evaporated from the surface of a porous wick housed in an evaporator to generate a capillary pumping force to drive the condensed working fluid to the evaporator.

Claims

1. A method for providing refrigeration to a refrigeration load comprising:

(A) generating refrigeration and using the refrigeration to condense working fluid;

(B) passing the condensed working fluid into an evaporator comprising a porous wick having a surface, providing a refrigeration load to the evaporator, flowing condensed working fluid onto the wick surface, and evaporating condensed working fluid from the wick surface to provide refrigeration to the refrigeration load and to generate a capillary pumping force; and

(C) withdrawing evaporated working fluid from the evaporator, wherein the condensed working fluid is passed to the evaporator at least in part by the capillary pumping force from the evaporation of the condensed working fluid from the wick surface.

2. The method of claim 1 wherein the working fluid comprises nitrogen.

3. The method of claim 1 wherein the refrigeration is generated using a cryocooler.

4. The method of claim 1 wherein the condensed working fluid is subcooled prior to entering the evaporator.

5. The method of claim 1 wherein the condensed working fluid is passed to the evaporator in part by gravitational force.

6. The method of claim 1 further comprising passing liquid cryogen from a reservoir to the evaporator.

7. The method of claim 1 wherein the porous wick comprises metal.

8. The method of claim 7 wherein the porous wick comprises metal foam.

9. The method of claim 1 wherein the evaporator is a plate-fin heat exchanger comprising a plurality of fins and heat from the refrigeration load is provided through the fins to the porous wick.

10. The method of claim 1 wherein the porous wick comprises a plurality of pores each having a diameter less than 0.5 millimeter.

11. A method for providing refrigeration to a refrigeration load comprising:

(A) generating refrigeration and using the refrigeration to condense working fluid;

(B) providing refrigeration from the condensed working fluid to the refrigeration load and thereafter passing the condensed working fluid into an evaporator comprising a porous wick having a surface, flowing condensed working fluid onto the wick surface, and evaporating condensed working fluid from the wick surface to generate a capillary pumping force; and

(C) withdrawing evaporated working fluid from the evaporator, wherein the condensed working fluid is passed to the evaporator at least in part by the capillary pumping force from the evaporation of the condensed working fluid from the wick surface.

12. The method of claim 11 wherein the condensed working fluid is evaporated in the evaporator by heat provided by an electric heater.

13. The method of claim 11 wherein the working fluid comprises nitrogen.

14. The method of claim 11 wherein the refrigeration is generated using a cryocooler.

15. The method of claim 11 wherein the condensed working fluid is subcooled prior to entering the evaporator.

16. The method of claim 11 further comprising passing liquid cryogen from a reservoir to the evaporator.

17. The method of claim 11 wherein the porous wick comprises metal.

18. The method of claim 17 wherein the porous wick comprises metal foam.

19. The method of claim 12 wherein the evaporator is a plate-fin heat exchanger comprising a plurality of fins and heat from the electric heater is provided through the fins to the porous wick.

20. The method of claim 11 wherein the porous wick comprises a plurality of pores each having a diameter less than 0.5 millimeter.