Fluid circuit heat transfer device for plural heat sources
View Patent ↗A heat sink or heat transfer device particularly for integrated circuits, uses a phase change working fluid in a cyclic flow path having at least one evaporator that serves multiple heat sources. The evaporator can be an integral vessel made of thermally conductive material to which the multiple heat sources are coupled, preferably at evaporation points that are placed on opposite sides of a fluid reservoir for the liquid phase of the working fluid that feeds the evaporation points via capillary flow through a wicking material.
1. A heat transfer device for removing heat energy from a plurality of electronic components separated from one another, the heat transfer device comprising:
a heat exchange structure containing a working fluid in a closed envelope defining an evaporator and a condenser that are coupled by a vapor line and a liquid return line to provide a circulating path for the working fluid, through vaporization of a liquid phase of the working fluid at the evaporator, condensation of a vapor phase of the working fluid at the condenser, and return of the working fluid from the condenser to the evaporator through the liquid return line;
wherein the evaporator comprises a bottom wall having a first single planar portion and one or more first side walls defining a reservoir and a second single planar portion and a third single planar portion with each of the second and third single planar portions elevated with respect to the first single planar portion and each of the second and third single planar portions at least partially defining respective evaporation chambers adjacent the reservoir, the evaporation chambers each being further defined by one or more second side walls adjacent the respective second and third single planar portions, the reservoir in flow communication with the liquid return line and positioned below the evaporation chambers, the evaporation chambers in flow communication with the vapor line, each of the second and third single planar portions provides a contact surface for application of heat energy for at least one of the plurality of electronic components and defines an evaporation surface disposed adjacent to and opposite a respective contact surface with the evaporation surfaces spaced apart from one another by the reservoir, and the evaporation chambers are supplied with the liquid phase of the working fluid from the reservoir, wherein each of the second and third single planar portions extends to the reservoir and each of the first, second, and third planar portions extends parallel to one another and orthogonal to the first one or more side walls.
2. The heat transfer device according to claim 1 , wherein the evaporator consists essentially of an integral vessel comprising thermally conductive material, the evaporation chambers being located at spaced positions within the integral vessel.
3. The heat transfer device according to claim 1 , wherein the reservoir is defined by at least one recessed well positioned in an enclosure defining the evaporator, the evaporation chambers being located between walls of the enclosure.
4. The heat transfer device according to claim 3 , wherein the evaporation chambers are asymmetrically arranged relative to one another.
5. The heat transfer device according to claim 3 , wherein the evaporation chambers extend to different radial distances from the reservoir.
6. The heat transfer device according to claim 5 , wherein at least one of the second and third portions of the bottom wall comprises a contact point for more than one of the plurality of electronic components.
7. The heat transfer device according to claim 5 , wherein each of the second and third portions of the bottom wall comprises a contact point for more than one of the plurality of electronic components.
8. The heat transfer device according to claim 1 , wherein the evaporation chambers are placed at different positions in the evaporator around the reservoir.
9. The heat transfer device according to claim 8 , wherein the evaporation chambers are placed at different positions around a perimeter of the reservoir.
10. The heat transfer device according to claim 9 , further comprising a vapor outlet opening defined in a wall of the evaporator so as to be in flow communication with the vapor line, whereby vapor from the evaporation chambers diffuses commonly into the vapor outlet.
11. The heat transfer device of claim 1 , further comprising a wicking material on the second and third portions of the bottom wall, wherein the reservoir contains the liquid phase of the working fluid to a level that is disposed below the evaporation chambers, covering the first portion of the bottom wall with the liquid phase of the working fluid, and leaving the wicking material on the second and third portions of the bottom wall exposed directly to the evaporation chambers when the bottom wall is horizontally oriented, the wicking material on the second and third portions of the bottom wall extending into the reservoir such that the liquid phase of the working fluid is diffused by capillary action and flows up onto the second and third portions of the bottom wall.
12. The heat transfer device according to claim 1 , further comprising a vapor outlet opening defined in a wall of the evaporator so as to be in flow communication with the vapor line, whereby vapor from the evaporation chambers diffuses commonly into the vapor outlet, wherein the vapor outlet is located directly above the reservoir.
13. A heat transfer device for removing heat energy from a plurality of electronic components separated from one another, the heat transfer device comprising:
a heat exchange structure containing a working fluid in a closed envelope defining an evaporator in flow communication with a vapor line, a condenser coupled to the evaporator by the vapor line, and a liquid return line to provide a circulating path for the working fluid, through vaporization of a liquid phase of the working fluid at the evaporator, condensation of a vapor phase of the working fluid at the condenser, and return of the working fluid from the condenser to the evaporator through the liquid return line;
wherein the evaporator comprises a bottom wall having a first portion at least partially defining a reservoir, and second and third portions extending to the reservoir and each being elevated with respect to the first portion and each of the second and third portions at least partially defining respective evaporation chambers adjacent the reservoir, the evaporation chambers each being further defined by one or more side walls adjacent the respective second and third portions, the reservoir in flow communication with the liquid return line, wherein each of the second and third portions provides a contact surface for application of heat energy for at least one of the plurality of electronic components and defines an evaporation surface disposed adjacent to and opposite a respective contact surface with the evaporation surfaces spaced apart from one another by the reservoir and the entirety of each evaporation surface defines a single plane, and wherein the evaporation surface of each of the second and third portions has a perimeter, respectively, defined by the one or more side walls and the reservoir and each evaporation surface perimeter is contiguous with a perimeter of the reservoir, and wherein the reservoir separates the evaporation surfaces so that the entirety of the perimeters are not in contact with one another.
14. The heat transfer device according to claim 13 , wherein at least two of the plurality of electronic components produce a different level of heat energy.
15. The heat transfer device according to claim 13 , wherein the evaporator includes a vapor accumulator, the vapor accumulator defining an aperture for connection of the evaporator to the vapor line.
16. The heat transfer device according to claim 15 , wherein the vapor accumulator is located directly above the reservoir.
17. The heat transfer device according to claim 13 , wherein the condenser comprises a conduit extending between the vapor line and liquid return line, and a plurality of fins in direct contact with the outer surface of the conduit.
18. The heat transfer device of claim 13 , further comprising a wicking material on the second and third portions of the bottom wall, wherein the reservoir contains the liquid phase of the working fluid filled to a level that is disposed below the evaporation chamber, covering the first portion of the bottom wall with the liquid phase of the working fluid, and leaving the wicking material on the second and third portions of the bottom wall exposed directly to the evaporation chamber when the bottom wall is horizontally oriented, the wicking material on the second and third portions of the bottom wall extending into the reservoir such that the liquid phase of the working fluid is diffused by capillary action and flows up onto the second and third portions of the bottom wall.
19. A heat transfer device for removing heat energy from a plurality of electronic components separated from one another, the heat transfer device comprising:
a heat exchange structure containing a working fluid in a closed envelope defining an evaporator arranged in flow communication with a vapor line and a liquid return line, and a condenser that is coupled to the evaporator by the vapor line and the liquid return line so as to provide a circulating path for the working fluid, through vaporization of a liquid phase of the working fluid at the evaporator, condensation of a vapor phase of the working fluid at the condenser, and return of the working fluid from the condenser to the evaporator through the liquid return line;
wherein the evaporator comprises a bottom wall having a first portion at least partially defining a reservoir and second and third portions extending immediately adjacent to the reservoir and each being elevated with respect to the first portion, each of the second and third portions positioned to provide a contact surface for at least one of the plurality of electronic components, and each of the second and third portions at least partially defining respective evaporation chambers adjacent the reservoir, the evaporation chambers each being further defined by one or more side walls adjacent the respective second and third portions, the reservoir in flow communication with the liquid return line, the evaporation chambers supplied with the liquid phase of the working fluid from the reservoir, wherein each of the second and third portions defines an evaporation surface disposed adjacent to and opposite a respective contact surface with the evaporation surfaces spaced apart from one another by the reservoir, and wherein the entirety of each evaporation surface of each of the second and third portions extends in a single plane and has a perimeter, respectively, defined by the one or more side walls and the reservoir, and wherein the reservoir separates the evaporation surfaces so that the entirety of the perimeters are not in contact with one another.
20. The heat transfer device according to claim 19 , wherein at least two of the plurality of electronic components produces a different level of heat energy.
21. The heat transfer device according to claim 19 , wherein the evaporator includes a vapor accumulator, the vapor accumulator defining an aperture for connection of the evaporator to the vapor line.
22. The heat transfer device according to claim 21 , wherein the vapor accumulator is located directly above the reservoir.
23. The heat transfer device according to claim 19 , wherein the condenser comprises a conduit extending between the vapor line and liquid return line, and a plurality of fins in direct contact with the outer surface of the conduit.
24. The heat transfer device according to claim 19 , and further comprising standoff blocks which extend between the bottom wall an opposite top wall of the evaporator.
25. The heat transfer device of claim 19 , further comprising a wicking material on the second and third portions of the bottom wall, wherein the reservoir contains the liquid phase of the working fluid filled to a level that is disposed below the evaporation chamber, covering the first portion of the bottom wall with the liquid phase of the working fluid, and leaving the wicking material on the second and third portions of the bottom wall exposed directly to the evaporation chamber when the bottom wall is horizontally oriented, the wicking material on the second and third portions of the bottom wall extending into the reservoir such that the liquid phase of the working fluid is diffused by capillary action and flows up onto the second and third portions of the bottom wall.