High heat flux evaporator, heat transfer systems

• US 7,931,072 B1
• Filed: 05/16/2006
• Issued: 04/26/2011
• Est. Priority Date: 10/02/2002
• Status: Active Grant

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Alliant Techsystems Incorporated (Northrop Grumman Corporation)
• Inventors: Khrustalev, Dmitry, Morgan, Michael J., Kroliczek, Edward J.
• Primary Examiner(s): Ciric; Ljiljana (Lil) V
• Application Number:
  US11/383,740
• Time in Patent Office: 1,806 Days
• Field of Search: 165/104.21, 165/104.26, 165/274
• US Class Current: 165/104.26
• CPC Class Codes: F25B 39/02 Evaporators
• CPC Class Codes: F28D 15/043 forming loops, e.g. capillary pumped loops
• CPC Class Codes: F28F 2255/18 sintered

Abstract

An evaporator includes an outer fluid enclosure, a liquid inlet port extending through the outer fluid enclosure, a liquid-distribution structure, a wick, and a vapor removal channel. The liquid-distribution structure is joined to the outer fluid enclosure to form a fluidly sealed hermetic chamber. The liquid-distribution structure includes a vapor barrier wall having an outer heat-receiving surface and the liquid-distribution structure is configured to distribute liquid over an inner surface of the vapor barrier wall. The wick is positioned inside the fluidly sealed hermetic chamber and is coupled to a liquid inlet port. The vapor removal channel is defined by and is in fluid communication with the wick and the liquid-distribution structure, and is near the outer heat-receiving surface of the vapor barrier wall. A thermal conductance of the liquid-distribution structure is higher than a thermal conductance of the wick.

Claims

1. An evaporator comprising:

an outer fluid enclosure;

a liquid inlet port coupled through the outer fluid enclosure;

a liquid-distribution structure joined to the outer fluid enclosure to form a fluidly sealed hermetic chamber, the liquid-distribution structure including a vapor barrier wall having an outer heat-receiving surface and being configured to distribute liquid over an inner surface of the vapor barrier wall;

a wick positioned inside the fluidly sealed hermetic chamber and being coupled to the liquid inlet port;

at least one vapor removal channel formed in the wick and being in fluid communication with the liquid-distribution structure, and being near the outer heat-receiving surface of the vapor barrier wall; and

a vapor header channel formed in the wick and being transverse to the at least one vapor removal channel, the at least one vapor removal channel extending from and being in communication with the vapor header channel;

wherein a thermal conductance of the liquid-distribution structure is higher than a thermal conductance of the wick.

2. The evaporator of claim 1, wherein the outer fluid enclosure includes a liquid barrier wall positioned such that the wick is between the liquid barrier wall and the liquid-distribution structure.

3. The evaporator of claim 2, further comprising a liquid flow channel formed in the liquid barrier wall and in fluid communication with the at least one vapor removal channel.

4. The evaporator of claim 2, wherein the liquid barrier wall includes at least one segment that has a conductivity that is lower than a conductivity of the wick.

5. The evaporator of claim 2, wherein the liquid barrier wall is made, at least in part, of a nickel alloy, stainless steel, ceramic, or plastic.

6. The evaporator of claim 2, wherein the liquid barrier wall includes at least one segment that is thinner than a remainder of the liquid barrier wall.

7. The evaporator of claim 1, further comprising a liquid flow channel positioned adjacent the wick and in fluid communication with the liquid inlet port.

8. The evaporator of claim 7, wherein the at least one vapor removal channel is remote from the liquid flow channel.

9. The evaporator of claim 7, wherein the liquid flow channel is remote from the outer fluid enclosure.

10. The evaporator of claim 9, further comprising a sealing device positioned between the outer fluid enclosure and the liquid flow channel, wherein the liquid flow channel is defined between the sealing device and the wick.

11. The evaporator of claim 1, wherein the at least one vapor removal channel is remote from the liquid inlet port.

12. The evaporator of claim 1, wherein the liquid-distribution structure comprises a porous device.

13. The evaporator of claim 12, wherein the porous device is bonded to the vapor barrier wall.

14. The evaporator of claim 12, wherein the porous device is formed integrally with the vapor barrier wall.

15. The evaporator of claim 12, wherein the porous device is made of the same material as the vapor barrier wall.

16. The evaporator of claim 12, wherein the porous device is sintered to the vapor barrier wall.

17. The evaporator of claim 12, wherein the porous device includes vapor passages and pores having a size sufficient to distribute liquid and wherein the porous device is in fluid communication with the vapor passages.

18. The evaporator of claim 17, wherein the at least one vapor removal channel is in fluid communication with at least some of the vapor passages of the liquid-distribution structure.

19. The evaporator of claim 1, wherein the wick is in fluid communication with at least a portion of the liquid-distribution structure.

20. The evaporator of claim 1, wherein a thickness of the wick is greater than a thickness of the liquid-distribution structure.

21. The evaporator of claim 1, wherein the wick and the liquid-distribution structure contact each other at a region that is smaller than a surface area of the liquid-distribution structure that faces the wick.

22. The evaporator of claim 1, wherein the outer fluid enclosure includes a liquid barrier wall and a side wall coupled to the liquid barrier wall.

23. The evaporator of claim 22, wherein the liquid inlet port extends through the liquid barrier wall.

24. The evaporator of claim 22, wherein the liquid inlet port extends through the side wall.

25. The evaporator of claim 1, further comprising a fluid outlet port through the outer fluid enclosure for sweepage of vapor and non-condensable gas within the liquid.

26. The evaporator of claim 1, wherein:

the outer fluid enclosure is cylindrical; and

the liquid-distribution structure and the wick are planar.

27. The evaporator of claim 1, wherein:

the outer fluid enclosure is annular; and

the wick and the liquid-distribution structure are annular.

28. The evaporator of claim 1, wherein the liquid-distribution structure comprises microchannels along a surface of the vapor barrier wall.

29. The evaporator of claim 28, wherein the at least one vapor removal channel is in fluid communication with at least some of the liquid-distribution structure microchannels.

30. The evaporator of claim 28, wherein the microchannels are formed into the vapor barrier wall at an inner surface of the vapor barrier wall.

31. The evaporator of claim 28, wherein the wick is in fluid communication with at least some of the liquid-distribution structure microchannels.

32. The evaporator of claim 31, wherein the at least one vapor removal channel is in direct fluid communication with an evaporation interface defined within the microchannels.

33. An evaporator comprising:

a liquid barrier wall;

a liquid inlet port through the liquid barrier wall;

a liquid-distribution structure including;

a vapor barrier wall having an outer heat-receiving surface; and

a porous device including vapor passages and pores having a size sufficient to distribute liquid and being in fluid communication with the vapor passages; and

a wick positioned between the liquid barrier wall and the liquid-distribution structure and coupled to the liquid inlet port, the wick comprising;

one or more vapor removal channels formed in the wick, and being in fluid communication with at least some of the vapor passages; and

a vapor header channel formed in the wick and being transverse to at least one of the one or more vapor removal channels, at least one of the one or more vapor removal channels extending from and being in communication with the vapor header channel;

wherein a thermal conductance of the liquid-distribution structure is higher than a thermal conductance of the wick.

34. The evaporator of claim 33, wherein the pores of the liquid-distribution structure are sized to provide pumping of the liquid from the wick.

35. The evaporator of claim 33, wherein the pores of the liquid-distribution structure have a size that is smaller than a size of pores of the wick.

36. An evaporator comprising:

a liquid barrier wall;

a liquid inlet port through the liquid barrier wall;

a fluid outlet port through the liquid barrier wall;

a liquid-distribution structure including;

a vapor barrier wall having an outer heat-receiving surface; and

microchannels along an inner surface of the vapor barrier wall;

a wick positioned between the liquid barrier wall and the liquid-distribution structure and being coupled to the liquid inlet port;

a sealing device positioned between the wick and the liquid barrier wall, the sealing device comprising at least one fluid channel formed in the sealing device, the at least one fluid channel being in direct fluid communication with the liquid inlet port and the fluid outlet port; and

one or more vapor removal channels defined at an interface between the wick and the liquid-distribution structure, and being in fluid communication with at least some of the liquid-distribution structure microchannels;

wherein a thermal conductance of the liquid-distribution structure is higher than a thermal conductance of the wick.

37. The evaporator of claim 36, wherein the wick and the liquid-distribution structure contact each other at contact regions that are smaller than a surface area of the wick that faces the liquid-distribution structure.

38. The evaporator of claim 37, wherein the microchannels adjacent the vapor barrier wall flow across the contact regions.

39. An evaporator comprising:

an outer fluid enclosure;

a liquid inlet port coupled through the outer fluid enclosure;

a fluid outlet port coupled through the outer fluid enclosure;

a liquid-distribution structure coupled to the outer fluid enclosure to define a fluidly sealed hermetic chamber and including a vapor barrier wall having an outer heat-receiving surface, the liquid-distribution structure being configured to distribute liquid over the vapor barrier wall;

a wick positioned inside the fluidly sealed hermetic chamber and being coupled to the liquid inlet port;

a sealing device positioned between the wick and the liquid barrier wall, the sealing device comprising at least one fluid channel formed in the sealing device, the at least one fluid channel being in direct fluid communication with the liquid inlet port and the fluid outlet port; and

a vapor removal channel formed in the wick and being in fluid communication with the liquid-distribution structure, and being in direct fluid communication with an evaporation interface defined between the liquid-distribution structure and the wick.

40. An evaporator comprising:

a liquid barrier wall;

a liquid inlet port coupled through the liquid barrier wall;

a vapor barrier wall extending along a vapor barrier plane;

a wick positioned between the liquid barrier wall and the vapor barrier wall, the wick coupled to the liquid inlet port;

a liquid flow channel located between the liquid barrier wall and the wick, the liquid flow channel fluidly coupled to the liquid inlet port;

at least one vapor removal channel that is located at an interface region between the wick and the vapor barrier wall and that extends along the vapor barrier plane in a first direction;

a vapor header channel that is located at the interface region between the wick and the vapor barrier wall, the vapor header channel extending along the vapor barrier plane, being in direct fluid communication with the at least one vapor removal channel, and being transverse to the first vapor removal channel; and

a vapor outlet port in direct fluid communication with the vapor header channel.

41. A heat transfer system comprising:

an evaporator comprising;

an outer fluid enclosure;

a liquid inlet port coupled through the outer fluid enclosure;

a liquid-distribution structure coupled to the outer fluid enclosure to define a fluidly sealed hermetic chamber, the liquid-distribution structure comprising;

a planar vapor barrier wall having an outer heat-receiving surface and an inner surface; and

a plurality of channels coupled to the vapor barrier wall and configured to distribute liquid over the inner surface of the vapor barrier wall;

a planar wick positioned inside the fluidly sealed hermetic chamber and being coupled to the liquid inlet port;

a sealing device positioned adjacent to the planar wick, the sealing device comprising at least one fluid channel formed in the sealing device, the at least one fluid channel being in direct fluid communication with the liquid inlet port; and

a vapor removal channel formed in a side of the wick in contact with the liquid-distribution structure and being in fluid communication with the liquid-distribution structure, and being in direct fluid communication with an evaporation interface defined between the liquid-distribution structure and the vapor barrier wall;

a condenser including a vapor inlet and a liquid outlet;

a vapor line providing fluid communication between the vapor removal channel of the evaporator and the vapor inlet of the condenser; and

a liquid line providing fluid communication between the liquid inlet port of the evaporator and the liquid outlet of the condenser.

42. The heat transfer system of claim 41, further comprising a reservoir in fluid communication with the liquid line.

43. The heat transfer system of claim 41, wherein the evaporator includes a fluid outlet port coupled through the outer fluid enclosure, and the heat transfer system further comprises a secondary system coupled to the evaporator at least through a sweepage line that couples to the fluid outlet port.

44. The heat transfer system of claim 43, wherein the fluid outlet port is in fluid communication with the wick.

45. The heat transfer system of claim 43, wherein the secondary system includes a secondary evaporator and a reservoir.