US20230204299A1

US20230204299A1 - Liquid-in and vapor-out composite liquid-vapor phase conversion heat dissipation device

Info

Publication number: US20230204299A1
Application number: US18/076,690
Authority: US
Inventors: Chien-Chung Feng
Original assignee: Long Victory Instruments Co Ltd
Current assignee: Long Victory Instruments Co Ltd
Priority date: 2021-12-23
Filing date: 2022-12-07
Publication date: 2023-06-29
Also published as: TW202326053A; TWI815257B

Abstract

A liquid-in and vapor-out composite liquid-vapor phase conversion heat dissipation device that includes a housing with a chamber connected to an inlet and outlet; a capillary structure in the chamber for maintaining a predetermined distance from the inlet and outlet, and separating the chamber into an liquid inlet chamber and a vapor outlet chamber. The liquid inlet chamber is spatially connected to the inlet, and the vapor outlet chamber is spatially connected to the outlet. A drainage structure located at the top surface of the bottom of the housing is affixed to the bottom of the capillary structure for diverting liquid from the liquid inlet chamber to the underside of the capillary structure. The bottom surface of the bottom of the housing is affixed to a heat source, and when the heat source is attached, the drainage structure is located above the heat source.

Description

FIELD OF THE DISCLOSURE

The present disclosure relates in general to a heat dissipation device, and more particularly, to a liquid-in and vapor-out composite liquid-vapor phase conversion heat dissipation device.

BACKGROUND OF THE DISCLOSURE

Taiwan Patent No. 1660151 discloses a loop heat pipe having an evaporation chamber, a vapor flow tube and a liquid flow tube connected to the evaporation chamber. The vapor flow tube and the liquid flow tube are then connected to a condensation section. The evaporation chamber, the vapor flow tube, the liquid flow tube and the condensation section together form a closed circulation channel, and an appropriate amount of working fluid (such as pure water) is provided inside the circulation channel. At least a capillary material is provided inside the evaporation chamber. The working fluid (e.g., pure water) is set inside this circulation channel, and at least the capillary material is set inside the evaporation chamber, and the evaporation chamber is affixed to a heating element (e.g., the central processing unit (CPU) of a computer). The condensation section is used to dissipate heat so that the vaporized working fluid can condense into a liquid in the condensation section and flow back into the evaporation chamber.
The aforementioned circuit heat pipe is a known technology, with technical features that focus on having the condensed working fluid in the return flow contacting the capillary material set up in the evaporation chamber in order to address the return interruption problem. Therefore, the aforementioned circuit heat pipe is not only set up in the evaporation chamber capillary material, but also extend the capillary material to the liquid flow tube and condensing section. The reason why the aforementioned loop heat pipe must be set up in this way is because of a closed-loop design. When the evaporation chamber is heated, the evaporation turns into vapor working fluid, and the gas pressure generated is often insufficient to push the condensation in the condensing section and becomes working fluid. Therefore, after the aforementioned technology extends the capillary material into the condensing section, the capillary material can be directly used to absorb water to quickly divert the liquid into the evaporation chamber.
Moreover, there is currently no design, including the known loop heat pipe which is of the closed-loop design that can provide a pre-determined pressure liquid from the outside. Even if such conventional design is modified, then the relative relationship and role of the capillary material inside the evaporation chamber would need to have a corresponding structure to match when the working fluid is heated and evaporates into vapor working fluid, and such matching structure simply does not exist in the conventional technology.
In addition, currently there are cold plates on the market that use only liquids (i.e., liquid-in and liquid-out) to carry away the heat. Compared with the latent heat required to transform a liquid into a vapor, the amount of heat that can be carried away by a liquid cooling plate is less. Also, the temperature of the liquid will rise during the working process, so the amount of heat that can be carried away is less than the aforementioned sensible heat principle.

SUMMARY OF THE DISCLOSURE

It is therefore an object of the present disclosure to provide a liquid-in and vapor-out composite liquid-vapor phase conversion heat dissipation device, which can be connected to a liquid tube and a vapor outlet tube, from which the liquid is continuously fed into the working fluid, and when heated, the thermal energy can make the working fluid continuously change into a vapor state and move outward from the vapor outlet tube, so as to provide continuous heat dissipation effect. Conversely, when the heat is low, the working fluid can enter into a liquid state and directly flow outward from the vapor outlet tube in the liquid state.
In order to achieve the above-mentioned object, the liquid-in and vapor-out composite liquid-vapor phase conversion heat dissipation device in the present disclosure includes: a housing having (a) a top, a bottom and a plurality of side walls, (b) a chamber inside the housing, and (c) an inlet and an outlet which are spatially connected to the chamber respectively. A capillary structure, which is affixed to the top, the bottom and a plurality of side walls of the housing, occupies most of the space of the chamber. Specifically, the capillary structure fills the chamber at a predetermined distance from both the inlet and the outlet, thereby spatially separating the chamber into a liquid inlet chamber, which is spatially connected to the inlet, and a vapor outlet chamber, which is spatially connected to the outlet; and a drainage structure, located at the top surface of the bottom of the housing, and affixed to the top surface of the bottom of the housing. The drainage structure is partially exposed to the liquid inlet chamber without being covered by the capillary structure, and the drainage structure is used to channel liquid from the liquid inlet chamber to the capillary structure below, whereby the bottom surface of the bottom of the housing is affixed to a heat source, and the drainage structure is located above the heat source.
With the above technical features, the present disclosure can be connected to a liquid tube and a vapor outlet tube, from which the liquid is continuously fed into the working fluid. When the heat is high, the working fluid can be continuously transformed into a vapor state and moved outward from the vapor outlet tube to provide continuous heat dissipation. When the heat is low, the working fluid can enter in a liquid state and directly flow outward from the vapor outlet tube in a liquid state.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to illustrate the technical features of the present disclosure in detail, an exemplary embodiment is illustrated with drawings, wherein:

FIG. 1 is a perspective view according to a first exemplary embodiment of the present disclosure;

FIG. 2 is a cross-sectional view along section line 2-2 in Figs according to the first exemplary embodiment of the present disclosure;

FIG. 3 is a cross-sectional view along section line 3-3 in Figs according to the first exemplary embodiment of the present disclosure;

FIG. 4 is a sectional view according to the first exemplary embodiment of the present disclosure, showing the state of the inlet and outlet with inlet receiver and outlet receiver;

FIG. 5 is a schematic diagram of the first exemplary embodiment of the present disclosure; and

FIG. 6 is a sectional view according to a second exemplary embodiment of the present disclosure.

Reference numbers in the figures are as follows: liquid-in and vapor-out composite liquid-vapor phase conversion heat dissipation device 10; housing 11; inlet channel 118; outlet channel 119; top 12; bottom 13; sidewall 14;
capacity chamber 16; liquid inlet chamber 168; vapor outlet chamber 169; inlet 18; outlet 19; capillary structure 21; drainage structure 31; grooves 311; liquid source 48; inlet tube 488; outlet tube; 489; liquid-in and vapor-out composite liquid-vapor phase conversion heat dissipation device 10′, liquid inlet chamber 168′; vapor outlet chamber 169′; inlet 18′; check valve 189′; capillary structure 21′; large diameter copper powder 211′; small diameter copper powder 212′; drainage structure 31′; working fluid 91; and heat source 99.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

In order to illustrate the technical features of the present disclosure in detail, the following exemplary embodiments are cited and illustrated with accompanying drawings, among others.
As shown in FIGS. 1 to 4 , the first preferred embodiment of the present disclosure provides a liquid-in and vapor-out composite liquid-vapor phase conversion heat dissipation device 10, consisting mainly of a housing 11, a capillary structure 21, and a drainage structure 31.
In particular, the housing 11 has a top 12, a bottom 13 and a number of side walls 14. The housing 11 has an internal chamber 16, and the housing 11 has an inlet 18 and an outlet 19 which are spatially connected to the chamber 16. The bottom surface of the bottom 13 of the housing 11 is used to adhere to a heat source 99 (see FIG. 5 ). In the first exemplary embodiment, the housing 11 is in the shape of a rectangle, so the number of the plural side walls 14 is four, and the four side walls 14 are two to two. In addition, the inlet 18 is for the working fluid 91 (e.g., pure water) to enter, and the outlet 19 is for the vaporized working fluid 91 to be dispersed outward. The outlet 19 is set at the top 12 of the housing 11, which helps the vapor working fluid 91 to disperse outwardly through the outlet 19 by the principle of rising hot air. However, the inlet 18 may also be located on one of the side walls 14 of the housing 11 as required, since this arrangement can be directly understood from FIGS. 1 to 3 of the present disclosure, and is therefore not shown in the figures. In addition, for the convenience of the connection line, an inlet channel 118 as shown in FIG. 4 can be extended outwardly from the housing 11 to correspond to the inlet 18, and an outlet channel 119 can be extended outwardly to correspond to the outlet 19. FIGS. 1 to 3 show an arrangement without the inlet channel 118 and outlet channel 119, mainly to illustrate that the present disclosure is not limited to using the inlet channel 118 and outlet channel 119.
In addition, it should be added that the housing 11 is not limited to a rectangular shape, and therefore other shapes such as square, polygon, circular, or cylindrical can be used. Since the housing structure in different shapes is directly understandable by those skilled in the art, such is not represented or shown.
The capillary structure 21 is affixed to the top 12, bottom 13 and aforementioned two opposite side walls 14 of the housing 11, thereby occupying most of the space of the chamber 16, which is filled with the chamber 16 but at a predetermined distance from the inlet 18 and the outlet 19. In addition, the capillary structure 21 is further separated from the other two opposite side walls 14 that are not attached by the predetermined distance, thus separating the chamber 16 into a liquid inlet chamber 168 and a vapor outlet chamber 169 that are not connected in space. The liquid inlet chamber 168 is spatially communicated with the inlet 18, and the vapor outlet chamber 169 is spatially communicated with the outlet 19. In the first exemplary embodiment, the capillary structure 21 is sintered with copper powder as an example.
The drainage structure 31 is located on the top surface of the bottom 13 of the housing 11, and attached to the bottom of the capillary structure 21. The drainage structure 31 is partially uncovered by the capillary structure 21 and is exposed to the liquid inlet chamber 168. In the first exemplary embodiment, the drainage structure 31 is formed by a number of grooves 311, and the two ends of the grooves 311 are connected to the liquid inlet chamber 168 and the vapor outlet chamber 169, respectively. In another embodiment, the grooves 311 can be formed by setting copper strips on the bottom 13 of the housing 11 and spacing them parallel to one another. The drainage structure 31 is located above the heat source 99.
The structure configuration of the first exemplary embodiment has been described above, and operational state of the first exemplary embodiment will be described hereinafter.
As shown in FIG. 5 , the inlet 18 is connected to a liquid source 48 prior to use. In fact, an inlet tube 488 can be used to connect the inlet channel 118 and the liquid source 48. An outlet tube 489 can be connected to the outlet channel 119 and the liquid source 48, which provides a constant supply of working fluid 91 at a predetermined rate into the inlet 18, which in turn provides a predetermined thrust to the working fluid 91 in the liquid inlet chamber 168. In addition, the bottom surface of the bottom 13 of the housing 11 is affixed to a heat source 99, which in FIG. 5 is the central processing unit as such as a computer.
During use, the liquid source 48 is driven to provide the working fluid 91, which enters the liquid inlet chamber 168 and is then drawn in by the capillary structure 21 until the capillary structure 21 is saturated, and the working fluid 91 is diverted by the drainage structure 31 to the vapor outlet chamber 169. The capillary structure 21 will occupy part of the space of the drainage structure 31, and the working fluid 91 will have a large flow resistance to flow directly from the liquid inlet chamber 168 to the vapor outlet chamber 169, which will cause the working fluid 91 to be saturated by the capillary structure 21, but will not flow out from the capillary structure 21 to the vapor outlet chamber 169 without resistance. The working fluid 91 is saturated by the capillary structure 21, but does not flow out from the capillary structure 21 to the vapor chamber 169 quickly without any resistance, but has only a little bit of leakage. Under such conditions, the heat emitted by the heat source 99 is conducted to the bottom 13 of the housing 11, which heats the working fluid 91 on the drainage structure 31, and the working fluid 91 in the vicinity of the drainage structure 31 is vaporized by the heat, and the vaporized working fluid 91 flows through the drainage structure 31 to the vapor outlet chamber 169, and then disperses outwardly by the outlet 19. The vaporized working fluid 91 is forced to flow only to the vapor outlet chamber 169 as the vaporized working fluid 91 enters the outlet tube 489 from the outlet 19 and then enters the liquid source 48. The liquid source 48 is then condensed into a liquid state.
In view of the above description, an external access is provided in the first exemplary embodiment to the liquid inlet tube 488 and the vapor outlet tube 489 to continuously provide the working fluid 91, and the housing 11 can absorb a large amount of heat energy when the liquid and vapor state of the working fluid 91 changes state when heated, thus achieving an excellent and continuous heat dissipation effect. Therefore, the present disclosure provides the composite liquid-vapor phase conversion heat dissipation device that combines liquid and vapor. In this way, the present disclosure is based on the latent heat principle to dissipate heat, and has a better heat dissipation effect than the liquid cooling plate.
It should be added that a condensing chamber (not shown in the drawings) can be added to the outlet tube 489 as required to ensure that the working fluid 91 in vapor form can be condensed to a liquid state before entering the liquid source 48. The condensing chamber is provided in the known circuit heat pipe and is therefore not shown in the drawings as it can be directly understood by the persons skilled in the art.
In addition, since the present disclosure uses a high heat absorption effect of the liquid state and vapor state of the working fluid 91 to dissipate heat, the amount of the working fluid 91 will not be very large because the amount of water in the process of transformation will not be very large, i.e., the supply rate of the liquid source 48 can be extremely low, and the rate of supplying the working fluid 91 only needs to be able to keep the capillary structure 21 from completely not absorbing the working fluid 91.
It should be further added that the heat source 99 as described above has a heating condition, that is, the condition of sufficient heat energy. However, if the liquid source 48 continues to supply the working fluid 91, but the heat source 99 does not heat up, i.e., when computer is turned off, the working fluid 91 will continue to leak in a liquid state into the vapor outlet chamber 169, and will eventually fill the vapor outlet chamber 169 completely, and then flow to the outlet 19. The working fluid 91 in the vicinity of the drainage structure 31 will still flow to the vapor outlet chamber 169 after being heated due to the hydraulic pressure, and the working fluid 91 in the vapor outlet chamber 169 will flow out from the outlet 19 at a higher rate than the aforementioned liquid supply rate. After a period of time, the vapor working fluid 91 in the vapor outlet chamber 169 will be completely discharged, and then the liquid supply rate of the liquid source 48 will be adjusted back to the normal value to return to the normal working condition as described above. It can be seen that the working form of the present disclosure can be of one configuration in which the working fluid 91 enters in liquid form and the vapor flows out, or of another configuration in which the working fluid 91 enters in liquid form and still flows out in liquid form, thereby rendering the working form as a composite form.
As shown in FIG. 6 , the present disclosure provides a second preferred embodiment of a liquid-in and vapor-out composite liquid-vapor phase conversion heat dissipation device 10′, which is mainly the same as the first embodiment, but differs in the following aspects.
The capillary structure 21′ has two different particle sizes of copper powders 211′ and 212′, whereby the large diameter copper powders 211′ are located at the bottom of the capillary structure 21′ in contact with the drainage structure 31′, while the small diameter copper powders 212′ are the main component of the capillary structure 21′, and most of the small diameter copper powders 212′ are located above the large diameter copper powder 211′.
The drainage structure 31′ is a metal woven mesh, which can be substantially a copper woven mesh, and the mesh of the metal woven mesh can be larger than the particle size of the large diameter copper powder 211′ of the capillary structure 21′.
The inlet 18′ is provided with a check valve 189′ to prevent the working fluid 91 in the liquid inlet chamber 168′ from flowing backwards.
In the second exemplary embodiment, since the large diameter copper powder 211′ of the capillary structure 21′ is located below, a large gap can be formed together with the drainage structure 31′, which helps to provide more space for the vapor working fluid 91 to flow in the heated evaporated state, and therefore flowing more easily to the vapor chamber 169′ in the vapor state.
The drainage structure 31′ is a woven metal mesh, which also provides space for the vapor working fluid 91 to flow.
After the working fluid 91 is heated and evaporates into vapor state, the working fluid 91 will not only move to the vapor outlet chamber 169′, but also to the liquid inlet chamber 168′ from a thrust formed so the check valve 189′ can further provide to prevent the working fluid 91 in the liquid inlet chamber 168′ from flowing back into the liquid inlet tube 488′.
The rest of the second exemplary embodiment is the same as the first exemplary embodiment, and will therefore not be repeated.

Claims

What is claimed is:

1. A liquid-in and vapor-out composite liquid-vapor phase conversion heat dissipation device, comprising:

a housing having (a) a top, a bottom and a plurality of side walls, (b) a chamber inside the housing, and (c) an inlet and an outlet spatially connected to the chamber, respectively;

a capillary structure affixed to the top, bottom and side walls of the housing, thereby occupying a substantial portion of the space in the chamber, the capillary structure in the chamber maintaining a predetermined distance from both the inlet and the outlet, thereby spatially separating the chamber into a liquid inlet chamber, which is spatially connected to the inlet, and the vapor outlet chamber, which is spatially connected to the outlet; and

a drainage structure disposed on a top surface of the bottom of the housing, and affixed to the bottom of the capillary structure, the drainage structure being partially uncovered by the capillary structure and exposed to the liquid inlet chamber, the drainage structure being used to divert liquid from the liquid inlet chamber to the bottom of the capillary structure,

wherein a bottom surface of the bottom of the housing is affixed to a heat source, and the drainage structure is located above the heat source.

2. The liquid-in and vapor-out composite liquid-vapor phase conversion heat dissipation device according to claim 1, wherein the housing is of a rectangular shape, and the number of the sidewalls is four, and wherein the four sidewalls are opposite to each other, and the capillary structure is attached to two of the opposite sidewalls, and separated from the other two sidewalls by a predetermined distance.

3. The liquid-in and vapor-out composite liquid-vapor phase conversion heat dissipation device according to claim 1, wherein the housing is one of a square, polygon, circular, or cylindrical shape.

4. The liquid-in and vapor-out composite liquid-vapor phase conversion heat dissipation device according to claim 1, wherein the inlet and the outlet are installed at the top of the housing.

5. The liquid-in and vapor-out composite liquid-vapor phase conversion heat dissipation device according to claim 1, wherein the inlet is pierced through one of the side walls of the housing.

6. The liquid-in and vapor-out composite liquid-vapor phase conversion heat dissipation device according to claim 1, wherein the capillary structure is a copper powder sintering structure having at least two different sizes in diameter, and wherein the large diameter copper powder is located at the bottom of the capillary structure in contact with the induced flow structure, and the small diameter copper powder is a main component of the capillary structure, and the small diameter copper powder is located above the aforementioned large diameter copper powder.

7. The liquid-in and vapor-out composite liquid-vapor phase conversion heat dissipation device according to claim 1, wherein the induced flow structure is composed of a plurality of grooves, and the two ends of the grooves are connected to the liquid-in chamber and the vapor-out chamber respectively.

8. The liquid-in and vapor-out composite liquid-vapor phase conversion heat dissipation device according to claim 1, wherein the drainage structure is a metal woven mesh, the capillary structure is a copper powder sintered structure, and the mesh of the metal woven mesh is larger than the copper powder particle size of the capillary structure.

9. The liquid-in and vapor-out composite liquid-vapor phase conversion heat dissipation device according to claim 1, wherein the inlet is equipped with a check valve.

10. The liquid-in and vapor-out composite liquid-vapor phase conversion heat dissipation device according to claim 1, wherein the housing has an inlet pipe extending outward to the inlet, and an outlet pipe extending outward to the outlet.