EVAPORATOR AND CONDENSER SECTION STRUCTURE FOR THERMOSIPHON
A thermosiphon device includes a closed loop evaporator section having one or more evaporation channels that are fed by a liquid return path, and a condenser section with one or more condensing channels. The condenser section may include a vapor supply path that is adjacent one or more condensing channels, e.g., located between two sets of condensing channels. Evaporator and/or condenser sections may be made from a single, flat bent tube, which may be bent about an axis parallel to the plane of the flat tube to form a turnaround and/or twisted about an axis along a length of the tube at the tube ends. A single tube may form both evaporator and condenser sections of a thermosiphon device, and an axially extending wall inside the tube in the evaporator section may separate an evaporator section from a liquid return section.
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This application claims the benefit of U.S. Provisional Application No. 62/044,604, filed Sep. 2, 2014, which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION1) Field of Invention
This invention relates generally to thermosiphon devices and other heat transfer devices that employ a two-phase fluid for cooling.
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- 2) Description of Related Art
Thermosiphon devices are widely used for cooling systems, such as integrated circuits and other computer circuitry. For example, U.S. Patent Publication 2013/0104592 discloses a thermosiphon cooler used to cool electronic components located in a cabinet or other enclosure.
SUMMARY OF THE INVENTIONIn accordance with an aspect of the invention, a thermosiphon device may have a closed loop evaporator section combined with a counterflow type condenser section. Generally, thermosiphon devices are made such that both the evaporator and condenser sections operate in a counterflow-type mode, or with a closed loop flow. Counterflow type devices tend to be less efficient than closed loop systems, but are suitable for certain applications and tend to be lower cost systems. On the other hand, closed loop systems can have a larger overall size, e.g., because of the dedicated flow paths and other components. By combining a closed loop evaporator section with a counterflow condenser section, the inventors have found that improved thermal performance in comparison to standard counterflow devices can be provided, but with lower equipment cost and overall size of the system.
For example, a thermosiphon cooling device may include a closed loop evaporator section having at least one evaporation channel with an inlet and an outlet. The evaporator section may be arranged to receive heat and evaporate a liquid in the at least one evaporation channel to deliver vapor to the evaporation channel outlet. A liquid return path, having an inlet and an outlet, may deliver condensed liquid to the at least one evaporation channel inlet, and the liquid return path may be arranged such that downward flow of condensed liquid from the liquid return path inlet to the liquid return path outlet is separate from an upward flow of vapor to the evaporation channel outlet. Thus, the evaporator section may operate with a closed loop flow. A condenser section of the device may include at least one condensing channel arranged to receive vapor from the at least one evaporation channel that flows upwardly in the condensing channel and arranged to transfer heat from the vapor to a surrounding environment to condense the vapor to a liquid which flows downwardly in the condensing channel to the liquid return path inlet. That is, the condenser section may operate in a counterflow arrangement in which vapor and condensed liquid flow in the same channel(s).
In some embodiments, a manifold may fluidly connect the at least one evaporation channel and the liquid return path with the at least one condensing channel. Thus, the manifold may function as a vapor/liquid separator such that vapor entering the manifold is separated from any liquid in the manifold and flows into condensing channels. On the other hand, liquid in the manifold may flow to the liquid return path. In some cases, the liquid return path inlet is positioned below the at least one evaporation channel outlet in the manifold so liquid preferentially flows into the liquid return path.
In one embodiment, the evaporator section is formed as a flat tube that is bent at a location where the liquid return outlet communicates with the at least one evaporation channel inlet. For example, the flat tube may be bent to form a 180 or other degree bend where the liquid return outlet communicates with the at least one evaporation channel inlet. In addition, or alternately, an outlet end of the flat tube at the evaporator channel outlet may be twisted about an axis along a length of the flat tube at the outlet end, and/or an inlet end of the flat tube at the liquid return path inlet may be twisted about an axis along a length of the flat tube at the inlet end. For example, inlet and/or outlet ends of the flat tube may be twisted 90 degrees about the axes. This type of arrangement may allow for simplified connections between the evaporator section and other parts of the thermosiphon device, e.g., the need for connectors to provide bends in the system flow path may be eliminated and replaced by bent/twisted tube sections.
In another aspect of the invention, a thermosiphon device may include a closed loop condenser section that has a liquid bypass or exit path for condensed liquid in the vapor supply path of the condenser section. This arrangement may reduce the concern regarding condensate forming in the vapor supply path, e.g., allowing the vapor supply path to be positioned closely to condensing channels of the device in such a way that condensate may form in the vapor supply path. For example, a thermosiphon cooling device includes a closed loop evaporator section having at least one evaporation channel with an inlet and an outlet and arranged to receive heat and evaporate a liquid in the at least one evaporation channel to deliver vapor to the evaporation channel outlet. A liquid return path, having an inlet and outlet, may deliver condensed liquid to the at least one evaporation channel. A condenser section may have a vapor supply channel arranged to receive vapor from the outlet of the at least one evaporation channel and deliver vapor to an upper end of the at least one condensing channel. The at least one condensing channel may be arranged to transfer heat from the vapor to a surrounding environment to condense the vapor to a liquid which flows downwardly in the condensing channel to the liquid return path inlet. The vapor supply channel may carry vapor flow, which is separate from condensed liquid flow in the condensing channels, yet the vapor supply channel may be immediately adjacent the at least one condensing channel. This is in contrast to systems which have a similar closed loop condenser arrangement, but have the vapor supply path physically separated from condensing channels. This separation is typically provided so that vapor in the vapor supply does not prematurely condense, which is known to disrupt the cyclical flow in a thermosiphon. However, the inventors have discovered that a vapor supply path can be provided immediately adjacent one or more condensing channels, and yet may be configured so that gravity-driven cyclical flow is not disrupted. In some embodiments, for example, an area where the vapor supply channel is fluidly connected to the outlet of the evaporator section may be provided with a liquid bypass or other flow path so that condensate in the vapor supply channel may drain to a manifold or other liquid return path of the device.
For example, an outlet end of the at least one evaporator channel may be inserted into or otherwise coupled to the vapor supply channel, and the coupling may be arranged so that liquid flowing downwardly in the vapor supply channel does not enter the outlet end of the at least one evaporator channel. Instead, the coupling between the outlet end and the vapor supply channel may have one or more gaps or other flow paths so that liquid in the vapor supply channel can bypass the outlet end and flow to a liquid return path of the device. In some embodiments, a manifold may fluidly connect the inlet of the liquid return path with a bottom of the at least one condensing channel, and any liquid that exits from the vapor supply channel may enter the manifold. As a result, the vapor supply channel may be surrounded by condensing channels without disrupting flow in the thermosiphon device because liquid in the vapor path can be removed. For example, the condenser section may have a plurality of parallel condensing channels, and the vapor supply channel may be located between two sets of the condensing channels, e.g., along a centerline of the condenser section.
In another aspect of the invention, a thermosiphon cooling device includes an evaporator section with at least one evaporation channel having an inlet and an outlet and arranged to receive heat and evaporate a liquid in the at least one evaporation channel to deliver vapor to the evaporation channel outlet. A liquid return path, having an inlet and outlet, may deliver condensed liquid to the at least one evaporation channel, e.g., by having the outlet fluidly coupled to the evaporation channel inlet. The evaporator section may be formed as a flat tube that is bent, e.g., at 180 degrees or more or less, at a location where the liquid return outlet communicates with the at least one evaporation channel inlet. Such an arrangement may make for a much simplified evaporator section, e.g., by eliminating one or more connections between parts of an evaporator section required by other arrangements. The bent, flat tube configuration for an evaporator section is also applicable to a condenser section. For example, a condenser section may have at least one condenser channel with an inlet and an outlet and arranged to transfer heat and condense a vapor in the at least one condenser channel to deliver condensed liquid to the condenser channel outlet. A vapor supply path, having an inlet and an outlet, may deliver evaporated liquid to the inlet of the at least one condenser channel, e.g., by having the outlet fluidly coupled to the condenser channel inlet. The condenser section may be formed as a flat tube that is bent, e.g., at 180 degrees or more or less, at a location where the vapor supply path outlet communicates with the at least one condenser channel inlet.
In some embodiments, a manifold may be fluidly connected to the at least one evaporation channel outlet and the liquid return path inlet, and the liquid return path inlet may be positioned below the at least one evaporation channel outlet in the manifold. This construction may make for a simplified device, since a single manifold may be used to make vapor and liquid connections between the evaporator section and the condenser section, as well as function as a vapor/liquid separator.
In some embodiments, an outlet end of the flat tube at the evaporator channel outlet may be twisted about an axis along a length of the flat tube at the outlet end, and/or an inlet end of the flat tube at the liquid return path inlet may be twisted about an axis along a length of the flat tube at the inlet end. For example, the inlet and outlet ends of the flat tube may be twisted 90 degrees about the axes. This arrangement may allow for relatively compact connections between the evaporator section and other portions of the thermosiphon device without the use of additional connectors. Instead, the tube ends may be twisted as needed to provide a suitably compact and correctly oriented connection.
In another aspect of the invention, a thermosiphon cooling includes a condenser section having a plurality of condensing channels arranged to receive evaporated liquid and arranged to transfer heat from the evaporated liquid to a surrounding environment to condense the evaporated liquid to a liquid which flows downwardly in the condensing channels. The condenser section may include first and second panels that sandwich a channel-defining member so as to form the plurality of condenser channels, with the first and second panels defining a lower manifold that fluidly connects lower ends of the condenser channels. Such an arrangement may provide a simple and efficient design which eliminates a variety of parts, such as an end cap for the upper ends of the condenser channels. In some embodiments, the first and second panels define an upper manifold that fluidly connects upper ends of the condenser channels, e.g., so the condenser section can be used as a closed loop type device. Alternately, or in addition, the channel-defining member may define a vapor supply channel, e.g., that is located between sets of condensing channels.
In another illustrative embodiment, a thermosiphon cooling device includes an evaporator section with a tube and an axially extending separation wall within the tube to separate at least one evaporation channel from a liquid return path in the tube. The axially extending separation wall may have a bottom end that is positioned away from a lower end of the tube and define the inlet for the at least one evaporation channel. This configuration may provide for a simplified evaporator device that includes a single tube and a plate or other element positioned inside the tube to function as a separation wall. In some embodiments, the tube may also define a condenser section, e.g., an inner surface of the tube may have fins or channels that define one or more condensing channels, one or more evaporation channels, and one or more liquid return paths. In some cases, the fins or channels at the at least one evaporation channel are different from the fins or channels at the liquid return path. For example, the channels or grooves at the evaporation channels may be arranged to enhance liquid boiling, whereas the channels or grooves at the liquid return path may be arranged to enhance condensate consolidation and flow.
Although not described above, conductive thermal transfer structure, such as a plurality of fins, may be in direct, conductive thermal contact with portions of an evaporator section, e.g., adjacent one or more evaporation channels, in contact with portions of a condenser section, e.g., adjacent one or more condensing channels, and/or associated with other parts of the thermosiphon device to influence heat transfer and/or cooling fluid flow.
These and other aspects of the invention will be apparent from the following description. Also, it should be appreciated that different aspects of the invention may be combined in a variety of different ways. For example, aspects related to closed loop evaporator flow and counterflow condenser flow may be combined with the use of a flat, bent tube evaporator, and/or with a condenser formed by sandwiching a channel-defining member between opposed panels.
The accompanying drawings, which are incorporated in and form a part of the specification, illustrate select embodiments of the present invention and, together with the description, serve to explain the principles of the inventions. In the drawings:
Aspects of the invention are not limited in application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. Other embodiments may be employed and aspects of the invention may be practiced or be carried out in various ways. Also, aspects of the invention may be used alone or in any suitable combination with each other. Thus, the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
In accordance with an aspect of the invention, a thermosiphon cooling device includes an evaporator section formed as a flat tube that is bent at a location where the liquid return outlet communicates with the at least one evaporation channel inlet. For example, the evaporator section may include at least one evaporation channel having an inlet and a liquid return path having an outlet that is fluidly coupled to the evaporation channel inlet, where the at least one evaporation channel and the liquid return path are formed as a flat tube that is bent at a location where the liquid return outlet communicates with the at least one evaporation channel inlet. For example, the flat tube may be arranged as a multi-port extruded (MPE) structure that is generally flat and has a plurality of parallel channels extending along the tube length, at least in the evaporator channel section. The MPE tube may be bent, e.g., to form a 180 degree bend, that defines an area where the liquid return path joins to the evaporation channel(s). Such an arrangement may make for a simplified, low-weight construction that can be made at relatively low cost.
For example,
In simplified form, the thermosiphon device 10 operates to cool heat generating devices by receiving heat at the heat-receiving area 5 of the evaporator section(s) 2 such that liquid in evaporation channels 22 boils or otherwise vaporizes. Heat may be received at the evaporation channels 22 by warm air (heated by the heat generating devices) flowing across a thermal transfer structure (e.g., heat sink fins) that is thermally coupled to the evaporation channels 22 or in other ways, such as by a direct conductive path, one or more heat pipes, a liquid heat exchanger, etc. Vapor flows upwardly from the evaporation channels 22 and into a vapor supply path 11 of a condenser section 1. The vapor continues to flow upwardly in the vapor supply path 11 until reaching a turnaround 14 of the condenser section 1. At this point, the vapor flows downwardly into one or more condensing channels 12 of the condenser section 1, where the vapor condenses to a liquid and flows downwardly into the manifold 3. Heat removed from the vapor during condensation may be transferred to thermal transfer structure coupled to the condensing channels 12, e.g., one or more fins conductively coupled to the condenser section 1 adjacent the condensing channels 12. In turn, heat may be removed from the thermal transfer structure by cool air flowing across the structure, by a liquid bath, a liquid heat exchanger, refrigerant coils, or other arrangement. The condensed liquid flows downwardly from the condensing channels 12 into a liquid return path 21 of an evaporator section 2 until reaching a turnaround 24 of the evaporator section 2. The liquid then enters an evaporator channel(s) 22 and the process is repeated.
In the
In accordance with another aspect of the invention, an inlet end and/or an outlet end of the tube forming the evaporator section(s) 2 may be twisted, e.g., about an axis that is along the length of the tube. In this embodiment, the inlet and outlet ends of the tube are twisted about an axis that extends along an approximate center of the tube along the length of the tube. However, twisting about other axes extending along a length of the tube or otherwise arranged are possible.
While in this embodiment only the evaporator section(s) 2 are formed from a bent, flat tube, one or more condenser sections 1 may be formed from a bent tube in addition or alternately to the evaporator section(s) 2. In such a case, the condenser section may have at least one condenser channel formed as a part of the tube with each condenser channel having an inlet and an outlet and arranged to transfer heat and condense a vapor in the at least one condenser channel to deliver condensed liquid to the condenser channel outlet. Another part of the tube may form a vapor supply path for delivering evaporated liquid to the inlet of the at least one condenser channel. The vapor supply path may have an inlet and an outlet that is fluidly coupled to the condenser channel inlet, and the flat tube may be bent at a location where the vapor supply path outlet communicates with the at least one condenser channel inlet. Moreover, ends of the tube may be twisted, e.g., in a way similar to the evaporator sections 2 shown in
That is, the manifold 3 in this embodiment provides a liquid flow path for condensed liquid to return to the evaporator section 2. The inlet end 27 of the evaporator section 2 (i.e., at the inlet to the liquid return path 21) is joined to the manifold 3, which fluidly couples the lower ends of the condenser channels 12 to the inlet end 27. Thus, vapor may flow upwardly in the vapor supply path 11 and into the upper ends of the condenser channels 12. Condensed liquid may flow downwardly into the manifold 3 and be routed to the inlet end 27 of the evaporator section 2. Since the inlet end 27 is positioned below the outlet end 26 of the evaporator section 2, liquid in the manifold 3 will flow first into the inlet end 27. In this embodiment, the manifold 3 includes a tube 35 that is coupled to each of the separate condenser sections 1, e.g., to allow for easier filling of the device 10 with cooling liquid and/or pressure equalization across different portions of the device.
Thermal transfer structure 9, such as one or more fins 9, may be thermally coupled to the condenser section(s) 1, e.g., in areas adjacent the condenser channels 12. This may assist in heat transfer from vapor in the condenser channels 12 and/or affect how cooling fluid flows across the thermal transfer structure 9. Of course, any suitable thermal transfer structure may be employed, including heat sink structures, heat pipes, heat exchangers, cold plates, etc.
In accordance with another aspect of the invention, a thermosiphon device may include a closed loop evaporator section, i.e., a liquid return path that leads to the inlet of one or more evaporation channels which have an outlet separate from the liquid return path, and a counterflow-type condenser section. That is, the condenser section may have at least one condensing channel arranged to receive vapor from at least one evaporation channel that flows upwardly in the condensing channel and arranged to transfer heat from the vapor to a surrounding environment to condense the vapor to a liquid which flows downwardly in the condensing channel to the liquid return path inlet. Thus, vapor to be condensed flows upwardly in the condensing channels while condensed liquid flows downwardly in the condensing channels. This is in contrast to a system like that in
In another aspect of the invention, a thermosiphon device includes a condenser section with first and second side panels that sandwich a channel-defining member so as to form a plurality of condenser channels and/or a vapor supply path. In some embodiments, the first and second side panels may define a lower manifold that fluidly connects lower ends of the condenser channels, and/or define an upper manifold that fluidly connects upper ends of the condenser channels. Such a structure may provide for a condenser section that is simple in construction, lightweight, and efficient. The channel-defining member may be arranged in a variety of ways, such as a stamped plate with walls to define the condensing channels when positioned between the side panels.
For example,
In this embodiment, thermal transfer structure 9 in the form of U-shaped fins 9 are attached to one or both of the panels 15, 16, e.g., to assist in transferring heat from vapor in the condensing channels 12. In this embodiment, the fins 9 are mounted parallel to the direction in which the condensing channels 12 extend, but could be positioned in other ways, such as at different angles. That is, this illustrative embodiment is configured to operate using natural convective flow such that air or other fluid in or around the fins 9 is heated and flows upwardly due to gravity. However, the fins 9 may be arranged for forced convection applications, e.g., where the fins 9 rotated 90 degrees so the fins 9 extend in a direction perpendicular to the direction along which the condensing channels 12 extend. Configuring the condenser section 1 to operate in as a forced convection device may enable the condenser section 1 to be reduced in size, assuming a power input is unchanged. It should also be noted that the thermal transfer structure 9 may take a variety of different shapes or configurations than that shown, e.g., the fins 9 may be louvered, corrugated, include pin elements, etc.
In accordance with another aspect of the invention, a header used to join a condenser section 1 and an evaporator section 2 may be arranged to include a connecting tube or other conduit so that adjacent headers can fluidly communicate with each other. That is, while the embodiments in
In some embodiments, thermosiphon devices ganged together to cool one or more heat generating devices may be fluidly coupled in ways or locations other than that shown in
Of course, other manifold arrangements are possible, such as that shown in
Although the embodiments above only describe the use of thermal transfer structure 9, such as a finned heat sink, with condenser sections 1, thermal transfer structure may be used with evaporator sections 2. For example,
In another aspect of the invention, a single tube may incorporate both an evaporator section and a condenser section. The evaporator section of the tube may include different internal protuberance and/or groove arrangements arranged to enhance condensation routing or liquid evaporation. Also, a part of the evaporation section may include a separation wall that extends axially in the tube and separates an evaporation portion from a liquid return path in the tube. The separation wall may have a low thermal conductivity and may made with grooves in the tube interior to retain the wall in place. For example,
The evaporator section 2 also includes grooves in the inner wall of the tube 25, e.g., to provide condensate liquid flow paths and evaporation channels. A separation wall 23 may be positioned in the tube 25 and extend axially along the tube 25 to separate evaporation channels 22 from a liquid return path 21 of the evaporator section 2.
The embodiments provided herein are not intended to be exhaustive or to limit the invention to a precise form disclosed, and many modifications and variations are possible in light of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. Although the above description contains many specifications, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of alternative embodiments thereof
The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”
The phrase “and/or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and/or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified.
The use of “including,” “comprising,” “having,” “containing,” “involving,” and/or variations thereof herein, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.
It should also be understood that, unless clearly indicated to the contrary, in any methods claimed herein that include more than one step or act, the order of the steps or acts of the method is not necessarily limited to the order in which the steps or acts of the method are recited.
While aspects of the invention have been described with reference to various illustrative embodiments, such aspects are not limited to the embodiments described. Thus, it is evident that many alternatives, modifications, and variations of the embodiments described will be apparent to those skilled in the art. Accordingly, embodiments as set forth herein are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit of aspects of the invention.
Claims
1. A thermosiphon cooling device including:
- an evaporator section including at least one evaporation channel having an inlet and an outlet and arranged to receive heat and evaporate a liquid in the at least one evaporation channel to deliver vapor to the evaporation channel outlet, and a liquid return path for delivering condensed liquid to the at least one evaporation channel, the liquid return path having an inlet and an outlet that is fluidly coupled to the evaporation channel inlet, wherein the evaporator section is formed as a flat tube that is bent at a location where the liquid return outlet communicates with the at least one evaporation channel inlet; OR
- a condenser section including at least one condenser channel having an inlet and an outlet and arranged to transfer heat and condense a vapor in the at least one condenser channel to deliver condensed liquid to the condenser channel outlet, and a vapor supply path for delivering evaporated liquid to the inlet of the at least one condenser channel, the vapor supply path having an inlet and an outlet that is fluidly coupled to the condenser channel inlet, wherein the condenser section is formed as a flat tube that is bent at a location where the vapor supply path outlet communicates with the at least one condenser channel inlet.
2. The device of claim 1, including the evaporator section and further comprising a manifold fluidly connected to the at least one evaporation channel outlet and the liquid return path inlet.
3. The device of claim 2, wherein the liquid return path inlet is positioned below the at least one evaporation channel outlet in the manifold.
4. The device of claim 2, wherein the flat tube is bent to form a 180 degree bend where the liquid return outlet communicates with the at least one evaporation channel inlet.
5. The device of claim 4, wherein an outlet end of the flat tube at the evaporator channel outlet is twisted about an axis along a length of the flat tube at the outlet end, and wherein an inlet end of the flat tube at the liquid return path inlet is twisted about an axis along a length of the flat tube at the inlet end.
6. The device of claim 5, wherein inlet and outlet ends of the flat tube are twisted 90 degrees about the axes.
7. A thermosiphon cooling device including:
- a closed loop evaporator section including at least one evaporation channel having an inlet and an outlet, the evaporator section being arranged to receive heat and evaporate a liquid in the at least one evaporation channel to deliver vapor to the evaporation channel outlet, and a liquid return path for delivering condensed liquid to the at least one evaporation channel inlet, the liquid return path having an inlet and an outlet that is fluidly coupled to the evaporation channel inlet and being arranged such that downward flow of condensed liquid from the liquid return path inlet to the liquid return path outlet is separated from an upward flow of vapor to the evaporation channel outlet, wherein the evaporator section is formed as a flat tube that is bent at a location where the liquid return outlet communicates with the at least one evaporation channel inlet; and
- a condenser section including at least one condensing channel arranged to receive vapor from the at least one evaporation channel that flows upwardly in the condensing channel and arranged to transfer heat from the vapor to a surrounding environment to condense the vapor to a liquid which flows downwardly in the condensing channel to the liquid return path inlet.
8. The device of claim 7, further comprising a manifold fluidly connecting the at least one evaporation channel and the liquid return path with the at least one condensing channel.
9. The device of claim 7, wherein the liquid return path inlet is positioned below the at least one evaporation channel outlet in the manifold.
10. The device of claim 7, wherein the flat tube is bent to form a 180 degree bend where the liquid return outlet communicates with the at least one evaporation channel inlet.
11. The device of claim 10, wherein an outlet end of the flat tube at the evaporator channel outlet is twisted about an axis along a length of the flat tube at the outlet end, and wherein an inlet end of the flat tube at the liquid return path inlet is twisted about an axis along a length of the flat tube at the inlet end.
12. The device of claim 11, wherein inlet and outlet ends of the flat tube are twisted 90 degrees about the axes.
13. The device of claim 7, wherein the condenser section includes first and second flat panels that sandwich a channel-defining member so as to form a plurality of condensing channels, the first and second flat panels defining a lower manifold that fluidly connects lower ends of the condenser channels.
14. A thermosiphon cooling device including:
- a closed loop evaporator section including at least one evaporation channel having an inlet and an outlet and arranged to receive heat and evaporate a liquid in the at least one evaporation channel to deliver vapor to the evaporation channel outlet, and a liquid return path for delivering condensed liquid to the at least one evaporation channel, the liquid return path having an inlet and an outlet that is fluidly coupled to the evaporation channel inlet; and
- a condenser section including a vapor supply channel arranged to receive vapor from the outlet of the at least one evaporation channel and to deliver vapor to an upper end of the at least one condensing channel that is arranged to transfer heat from the vapor to a surrounding environment to condense the vapor to a liquid which flows downwardly in the condensing channel to the liquid return path inlet, wherein the vapor supply channel is adjacent the at least one condensing channel.
15. The device of claim 14, further comprising a manifold fluidly connecting the inlet of the liquid return path with a bottom of the at least one condensing channel.
16. The device of claim 14, wherein a wall that defines at least a part of the vapor supply channel defines at least a part of the adjacent at least one condensing channel.
17. The device of claim 14, wherein an outlet end of the at least one evaporator channel is inserted into the vapor supply channel.
18. The device of claim 14, wherein an outlet end of the at least one evaporator channel is coupled to the vapor supply channel such that liquid flowing downwardly in the vapor supply channel does not enter the outlet end of the at least one evaporator channel.
19. The device of claim 18, further comprising a manifold fluidly connecting the inlet of the liquid return path with a bottom of the at least one condensing channel, and wherein liquid flowing downwardly in the vapor supply channel enters the manifold.
20. The device of claim 14, wherein the condenser section includes a plurality of parallel condensing channels, and wherein the vapor supply channel is located between two sets of the condensing channels.
21. The device of claim 14, wherein the condenser section includes first and second flat panels that sandwich a channel-defining member so as to form a plurality of condensing channels and the vapor supply channel, the first and second flat panels defining a lower manifold that fluidly connects lower ends of the condenser channels, and defining an upper manifold that fluidly connects upper ends of the condensing channels and the vapor supply channel.
22. The device of claim 14, wherein the evaporator section is formed as a flat tube that is bent at a location where the liquid return outlet communicates with the at least one evaporation channel inlet.
23. The device of claim 12, wherein the flat tube is bent to form a 180 degree bend where the liquid return outlet communicates with the at least one evaporation channel inlet.
24. The device of claim 23, wherein an outlet end of the flat tube at the evaporator channel outlet is twisted about an axis along a length of the flat tube at the outlet end, and wherein an inlet end of the flat tube at the liquid return path inlet is twisted about an axis along a length of the flat tube at the inlet end.
25. The device of claim 24, wherein inlet and outlet ends of the flat tube are twisted 90 degrees about the axes.
26. The device of claim 25, wherein the condenser section includes a plurality of condensing channels, and wherein the outlet end of the flat tube is fluidly coupled to the vapor supply channel, and the inlet end of the flat tube is fluidly coupled to a manifold that fluidly couples lower ends of the plurality of condensing channels.
27. A thermosiphon cooling device including:
- a condenser section including a plurality of condensing channels arranged to receive evaporated liquid and arranged to transfer heat from the evaporated liquid to a surrounding environment to condense the evaporated liquid to a liquid which flows downwardly in the condensing channels, wherein the condenser section includes first and second panels that sandwich a channel-defining member so as to form the plurality of condenser channels, the first and second panels defining a lower manifold that fluidly connects lower ends of the condenser channels.
28. The device of claim 27, wherein the first and second panels define an upper manifold that fluidly connects upper ends of the condenser channels.
29. The device of claim 27, wherein the channel-defining member additionally defines a vapor supply channel.
30. The device of claim 29, wherein the vapor supply channel is located between sets of condensing channels.
31. A thermosiphon cooling device including:
- an evaporator section including a tube with an axially extending separation wall within the tube to separate at least one evaporation channel having an inlet and an outlet from a liquid return path for delivering condensed liquid to the at least one evaporation channel, the axially extending wall having a bottom end that is positioned away from a lower end of the tube and defining the inlet for the at least one evaporation channel.
32. The device of claim 31, wherein the tube defines a condenser section.
33. The device of claim 31, wherein an inner surface of the tube has fins or channels at the at least one evaporation channel.
34. The device of claim 33, wherein the inner surface includes fins or channels at the liquid return path, and the fins or channels at the at least one evaporation channel are different from the fins or channels at the liquid return path.
35. The device of claim 31, wherein the tube has upper and lower sections, the evaporator section being located at the lower section of the tube, the device further comprising a condenser section at the upper section of the tube.
Type: Application
Filed: Sep 2, 2015
Publication Date: Mar 3, 2016
Applicant: Aavid Thermalloy, LLC (Laconia, NH)
Inventors: Morten Søegaard Espersen (Bologna), Maria Luisa Angrisani (Bologna), Dennis N. Jensen (Bologna), Sukhvinder S. Kang (Concord, NH)
Application Number: 14/843,210