Loop heat pipe evaporator
A loop heat pipe evaporator includes a porous primary wick, and a nonporous envelope unseparatingly surrounding the primary wick. The primary wick and the envelope are of one-piece construction.
1. A loop heat pipe capillary pump, comprising:
a loop heat pipe evaporator, comprising,
a porous primary wick;
a secondary wick surrounded by the primary wick; and
a nonporous envelope unseparatingly surrounding the primary wick; and
a compensation chamber separate from the loop heat pipe evaporator,
wherein the compensation chamber is connected to an interior of the loop heat pipe evaporator by the secondary wick such that fluid transfer between the compensation chamber and the loop heat pipe evaporator is driven by a capillary force,
wherein the secondary wick extends past the primary wick and into the compensation chamber,
wherein the primary wick, the secondary wick, and the envelope are of one-piece construction,
wherein the primary wick comprises a plurality of vapor passageways positioned along a periphery of the primary wick, and
wherein the plurality of vapor passageways has different cross-sectional areas from each other.
2. The loop heat pipe capillary pump of claim 1 , wherein the one-piece construction of the primary wick, the secondary wick, and the envelope is fabricated by a direct metal laser sintering process.
3. The loop heat pipe capillary pump of claim 1 , wherein the compensation chamber includes an external structure defining an integrated one piece support structure.
4. The loop heat pipe capillary pump of claim 1 , wherein the compensation chamber is integrally formed with the primary wick, the secondary wick, and the envelope.
5. The loop heat pipe capillary pump of claim 1 , wherein the plurality of vapor passageways is recessed relative to its peripheral surface.
6. The loop heat pipe capillary pump of claim 1 , wherein the plurality of vapor passageways has a noncircular geometry.
7. The loop heat pipe capillary pump of claim 1 , wherein a cross-sectional area of the plurality of vapor passageways increase based on a distance from a vapor line.
8. The loop heat pipe capillary pump of claim 1 , wherein the plurality of vapor passageways has a length to diameter ratio of greater than 3:1.
9. The loop heat pipe capillary pump of claim 1 , wherein the plurality of vapor passageways is made with the primary wick by a direct metal laser sintering process.
10. The loop heat pipe capillary pump of claim 1 , wherein the primary wick comprises:
a first pore size region surrounding the plurality of vapor passageways; and
a second pore size region surrounded by the first pore size region,
wherein a pore size of the second pore size region is greater than a pore size of the first pore size region.
11. The loop heat pipe capillary pump of claim 10 , further comprises a bayonet tube surrounded by the secondary wick, wherein the pore size of the second pore size region and the secondary wick increasing in an increasing inward direction away from the first pore size region.
12. The loop heat pipe capillary pump of claim 10 , wherein the first pore size region has a pore size of about 1 μm.
13. The loop heat pipe capillary pump of claim 10 , wherein the first pore size region has a pore size between about 0.5 μm and about 10 μm, and the second pore size region has a pore size of greater than 10 μm.
14. The loop heat pipe capillary pump of claim 1 , wherein the secondary wick and the compensation chamber incorporate a geometry subtending an angle ranging between about 5 degrees and about 90 degrees.
15. A loop heat pipe capillary pump, comprising:
a loop heat pipe evaporator, comprising:
a porous primary wick; and
a nonporous envelope unseparatingly partially surrounding the primary wick; and
a secondary wick; and
a compensation chamber separate from the loop heat pipe evaporator,
wherein the compensation chamber is connected to an interior of the loop heat pipe evaporator by the secondary wick such that fluid transfer between the compensation chamber and the loop heat pipe evaporator is driven by a capillary force,
wherein the primary wick and the envelope are of one-piece construction,
wherein the loop heat pipe evaporator has a non-circular cross section,
wherein the primary wick comprises a plurality of vapor passageways positioned along a periphery of the primary wick, wherein the plurality of vapor passageways has different cross-sectional area from each other, and
wherein a cross-sectional area of the plurality of vapor passageways increases based on a distance from a vapor line.
16. The loop heat pipe capillary pump of claim 15 , wherein the cross section of the loop heat pipe evaporator is generally rectangular.
17. The loop heat pipe capillary pump of claim 15 , wherein the primary wick unseparatingly surrounding a secondary wick, wherein the secondary wick is fabricated with the primary wick and the envelope as one-piece construction.
18. The loop heat pipe capillary pump of claim 3 , further comprising an internal support pillar connected to the external structure of the compensation chamber.
19. A loop heat pipe capillary pump, comprising:
a loop heat pipe evaporator, comprising,
a porous primary wick;
a secondary wick surrounded by the primary wick; and
a nonporous envelope unseparatingly surrounding the primary wick; and
a compensation chamber separate from the loop heat pipe evaporator,
wherein the compensation chamber is connected to an interior of the loop heat pipe evaporator by the secondary wick such that fluid transfer between the compensation chamber and the loop heat pipe evaporator is driven by a capillary force,
wherein the secondary wick extends past the primary wick and into the compensation chamber,
wherein the primary wick, the secondary wick, and the envelope are of one-piece construction,
wherein the compensation chamber includes an external structure defining an integrated one piece support structure, and
wherein an internal support pillar is connected to the external structure of the compensation chamber.