Evaporator for use in a heat transfer system
View Patent ↗An evaporator includes a liquid barrier wall made of a ceramic material, a vapor barrier wall made of a ceramic material, and a wick made of a ceramic material and being positioned between the liquid barrier wall and the vapor barrier wall.
1. An evaporator comprising:
a liquid barrier wall comprising a ceramic material;
a vapor barrier wall comprising a ceramic material;
a wick comprising a ceramic material and being positioned between the liquid barrier wall and the vapor barrier wall;
a vapor channel formed at an interface between the wick and the vapor barrier wall; and
a liquid channel formed at an interface between the wick and the liquid barrier wall.
2. The evaporator of claim 1 , wherein the liquid barrier wall and the vapor barrier wall are hermetically sealed to each other.
3. The evaporator of claim 1 , wherein the liquid barrier wall and the vapor barrier wall are configured to uniformly contact the wick.
4. The evaporator of claim 1 , wherein the liquid barrier wall and the vapor barrier wall are bonded to the wick.
5. The evaporator of claim 1 , wherein the vapor barrier wall has a flat geometry that is configured to engage a flat heat source.
6. The evaporator of claim 1 , wherein the liquid barrier wall comprises at least one protrusion formed within the evaporator and wherein the at least one protrusion is at least partially received in a portion of the wick.
7. The evaporator of claim 1 , wherein the vapor channel is formed in the wick.
8. The evaporator of claim 1 , wherein the vapor channel is formed in the vapor barrier wall.
9. The evaporator of claim 1 , wherein the vapor channel is formed in both the wick and the vapor barrier wall.
10. The evaporator of claim 1 , wherein the vapor barrier wall is formed of a material with a thermal expansion coefficient that matches a thermal expansion coefficient of a heat source that is being cooled.
11. The evaporator of claim 1 , wherein the vapor barrier wall includes at least one of: aluminum oxide, silicon nitride, aluminum nitride, silicon carbide, beryllium oxide, and diamond.
12. The evaporator of claim 1 , wherein the liquid barrier wall comprises an annular wall formed within the evaporator and wherein the wick is at least partially received within the annular wall.
13. The evaporator of claim 1 , wherein the liquid channel is formed in the wick.
14. The evaporator of claim 1 , wherein the liquid channel is formed in the liquid barrier wall.
15. The evaporator of claim 1 , wherein the liquid channel is formed in both the wick and the liquid barrier wall.
16. The evaporator of claim 1 , wherein the liquid channel has a trapezoidal shape along a cross-section normal to fluid flow to facilitate separation of vapor from liquid.
17. The evaporator of claim 1 , wherein the liquid barrier wall exhibits a thermal conductivity that is less than the thermal conductivity of at least one of the wick and the vapor barrier wall.
18. The evaporator of claim 1 , wherein the liquid barrier wall comprises at least one of aluminum oxide, silicon dioxide, zirconium oxide, glass, a glass ceramic, mullite, and a chemically bonded ceramic.
19. The evaporator of claim 1 , wherein the wick exhibits a thermal conductivity that is less than the thermal conductivity of the vapor barrier wall.
20. The evaporator of claim 1 , wherein the wick comprises at least one of aluminum oxide, silicon dioxide, zirconium oxide, mullite, glass, glass ceramic, and chemically bonded ceramic.
21. The evaporator of claim 1 , wherein the liquid barrier wall comprises a material that has an expansion coefficient that matches the expansion coefficient of the wick.
22. The evaporator of claim 1 , wherein the liquid barrier wall comprises a material that has an expansion coefficient that matches the expansion coefficient of the vapor barrier wall.
23. The evaporator of claim 1 , wherein the liquid barrier wall includes:
a fluid inlet port, and
a fluid outlet port.
24. The evaporator of claim 1 , wherein the liquid barrier wall includes:
a fluid inlet port, and
a vapor outlet port.
25. The evaporator of claim 24 , wherein the liquid barrier wall includes a fluid outlet port.
26. The evaporator of claim 1 , wherein the liquid barrier wall, the vapor barrier wall, and the wick are cylindrical along a cross-section that is normal to fluid flow.
27. The evaporator of claim 1 , wherein the liquid barrier wall, the vapor barrier wall, and the wick are polygonal along a cross-section that is normal to fluid flow.
28. The evaporator of claim 1 , wherein the wick includes:
a vapor side part, and
a liquid side part that has a thermal conductivity lower than the thermal conductivity of the vapor side part and that has a pore size that is larger than the pore size of the vapor side part.
29. The evaporator of claim 28 , wherein the vapor side part has a pore size in a range of about 1 μm to 10 μm.
30. The evaporator of claim 28 , wherein the liquid side part has a pore size in the range of about 10 μm to 20 μm.
31. An evaporator comprising:
a substantially planar liquid barrier wall comprising a ceramic material and having at least one fluid flow channel formed therein, the liquid barrier wall having at least one fluid port extending through the liquid barrier wall to a portion of the at least one fluid flow channel; and
a wick comprising a ceramic material positioned adjacent the liquid barrier wall, wherein the liquid barrier wall contains a fluid at least partially within the evaporator and proximate to the wick.
32. The evaporator of claim 31 , wherein the liquid barrier wall uniformly contacts the wick.
33. The evaporator of claim 31 , wherein the liquid barrier wall is uniformly bonded to the wick.
34. The evaporator of claim 31 , further comprising a vapor barrier wall positioned adjacent the wick configured to receive a heat source and contain vapor.
35. The evaporator of claim 34 , further comprising a plurality of vapor channels formed at an interface between the wick and the vapor barrier wall.
36. The evaporator of claim 31 , wherein the liquid barrier wall is electrically insulating.
37. The evaporator of claim 31 , wherein the wick is electrically insulating.
38. An evaporator comprising:
a wick having a plurality of vapor removal channels formed therein extending along an outer surface of the wick at an interface between the wick and a vapor barrier wall;
a vapor barrier wall adjacent the wick, wherein the vapor barrier wall comprises a ceramic material exhibiting a thermal expansion coefficient that is within 50% of a thermal expansion coefficient of a semiconductor heat source directly coupled to the evaporator, and wherein the evaporator is configured as a part of a two-phase loop heat transfer system; and
a liquid barrier wall, wherein the wick is positioned between the vapor barrier wall and the liquid barrier wall.
39. The evaporator of claim 38 , ceramic material exhibits a thermal expansion coefficient that is within about 20% of the thermal expansion coefficient of the semiconductor heat source coupled to the evaporator.
40. The evaporator of claim 38 , wherein the wick comprises a vaporization piece having a first side bonded to the vapor barrier wall and a second, opposing side having a plurality of grooves formed therein and wherein the plurality of grooves formed in the vaporization piece of the wick are positioned adjacent to the plurality of vapor removal channels formed in the wick and extend in a direction perpendicular to the plurality of vapor removal channels.
41. The evaporator of claim 38 , wherein a thermal conductivity of the vapor barrier wall is greater than a thermal conductivity of the wick.
42. The evaporator of claim 38 , wherein the vapor barrier wall comprises at least one of aluminum oxide or diamond, and the thermal conductivity of the vapor barrier wall is between about 20 W/mK to 1000 W/mK.
43. The evaporator of claim 38 , further comprising a liquid channel formed at an interface between the wick and the liquid barrier wall.
44. The evaporator of claim 43 , wherein a thermal conductivity of the vapor barrier wall is greater than a thermal conductivity of the liquid barrier wall.
45. The evaporator of claim 43 , wherein the wick has a porosity of between about 30% and about 70%.
46. The evaporator of claim 43 , wherein the wick includes pores having a radius in the range of about 1 micron to 10 microns.
47. The evaporator of claim 43 , wherein the wick comprises at least one of aluminum oxide, silicon dioxide, zirconium oxide, glass, glass ceramic, and chemically bonded ceramic.
48. The evaporator of claim 43 , wherein the liquid barrier wall comprises a material having a thermal expansion coefficient that is substantially equal to the thermal expansion coefficient of the semiconductor heat source coupled to the evaporator.