CN115597412A

CN115597412A - Loop heat pipe

Info

Publication number: CN115597412A
Application number: CN202211211827.8A
Authority: CN
Inventors: 张永海; 马祥; 杨小平; 魏进家
Original assignee: Xian Jiaotong University
Current assignee: Xian Jiaotong University
Priority date: 2022-09-30
Filing date: 2022-09-30
Publication date: 2023-01-13

Abstract

The invention discloses a loop heat pipe for radiating heat of a smart phone, which comprises a first channel, a second channel, an evaporator and a condenser, wherein the evaporator is used for absorbing heat radiated by the smart phone, the evaporator comprises a shell and a capillary core, the capillary core is used for filling a liquid working medium, the shell is provided with a sealed cavity, the capillary core is arranged in the sealed cavity and isolates the sealed cavity into a compensation cavity and a steam cavity, a heat insulating layer is arranged on the cavity wall of the compensation cavity, which is far away from the capillary core, one end of the first channel is communicated with the steam cavity, the other end of the first channel is communicated with the condenser, one end of the second channel is communicated with the compensation cavity, and the other end of the second channel is communicated with the condenser. This loop heat pipe's compensation chamber does not produce steam, and the steam chamber can produce a large amount of steam to make the atmospheric pressure in the steam chamber be greater than the atmospheric pressure in compensation chamber, get into the condenser through first passageway with the steam in the drive steam chamber, the condensation gets into the compensation chamber through the second passageway after becoming liquid, ensures that liquid working medium and steam can the circulation flow, makes the loop heat pipe constantly run.

Description

Loop heat pipe

Technical Field

The invention relates to the technical field of electronic element heat dissipation, in particular to a loop heat pipe.

Background

In recent years, with the enhancement of the functions of smart phones, the heat generation power is gradually increased. Heat concentration in the smartphone can negatively affect user comfort and experience, and is therefore very important for thermal management of the smartphone. For smart phones, it is difficult to dissipate with forced air convection. At present, a thin metal plate and a graphite sheet material with high heat conductivity are attached to a smart phone, and are often limited by the influence of the heat conductivity and cannot respond quickly to the heat generated by a high heat component.

As a good heat dissipation technical means, the loop heat pipe has better heat exchange performance than a heat conduction material, and is an effective scheme for solving the problem of heat dissipation of the smart phone. The heat dissipation space in the smart phone is very small, and the loop heat pipe is installed on a small and thin smart phone, so that the loop heat pipe needs to be miniaturized and flattened. The direction of the smart phone can be changed at any time in the using process, so that the direction of the loop heat pipe is changed, and the heat transfer performance in the loop heat pipe is influenced under the action of gravity. If the air pressure on the two sides of the loop heat pipe is balanced, the liquid working medium and the steam in the loop heat pipe cannot realize flowing circulation, so that the loop heat pipe stops running, and the heat dissipation performance of the smart phone is affected.

Disclosure of Invention

Therefore, a loop heat pipe is needed to be provided to solve the technical problem that in the prior art, the air pressure at two sides of the loop heat pipe is balanced, and the liquid working medium and the steam in the loop heat pipe cannot realize flowing circulation, so that the loop heat pipe stops running.

The invention provides a loop heat pipe for radiating heat of a smart phone, which comprises:

a first channel;

a second channel;

the evaporator is used for absorbing heat emitted by the smart phone and comprises a shell and a capillary core, the capillary core is used for filling a liquid working medium, the shell is provided with a sealed cavity, the capillary core is arranged in the sealed cavity and separates the sealed cavity into a compensation cavity and a steam cavity, and a heat insulation layer is arranged on the cavity wall of the compensation cavity, which is far away from the capillary core; and

the condenser, the one end of first passageway with steam chamber intercommunication, the other end with the condenser intercommunication, the one end of second passageway with compensation chamber intercommunication, the other end with the condenser intercommunication.

Further, the heat insulation layer is high-temperature adhesive tape.

Further, the thermal insulation layer is a coating with low thermal conductivity.

Further, the first channel, the second channel, the evaporator and the condenser are of an integrally formed structure.

Furthermore, a steam opening is arranged in the steam cavity, the steam opening is communicated with one end, far away from the condenser, of the first channel, the compensation cavity is provided with a liquid inlet, the liquid inlet is communicated with one end, far away from the condenser, of the second channel, and the size of the steam opening is larger than that of the liquid opening.

Further, the capillary core is of a bent structure.

Furthermore, the one end that the second passageway is close to the compensation chamber is provided with annotates the liquid mouth, it is used for supplying outside liquid working medium to get into the compensation chamber to annotate the liquid mouth.

In another embodiment, the invention further discloses a loop heat pipe, which includes a capillary core, a first plate body and a second plate body, wherein the first plate body is provided with a communicated groove, the second plate body is covered with the first plate body, so that the groove forms a first channel and a second channel, a condenser is arranged between the first end of the first channel and the first end of the second channel, an accommodating cavity is arranged between the second end of the first channel and the second end of the second channel, the capillary core is arranged in the accommodating cavity and separates the accommodating cavity into a compensation cavity and a steam cavity, and a heat insulating layer is arranged on the wall, far away from the capillary core, of the compensation cavity.

Further, the first plate body comprises a first bending part, a second bending part and a third bending part, the first end of the first bending part is connected with the first end of the second bending part, the second end of the first bending part is connected with the first end of the third bending part, the second end of the second bending part is connected with the second end of the third bending part, the first channel is arranged on the first bending part, the second channel is arranged on the second bending part, and the capillary core is arranged on the third bending part.

Further, the first bending part, the second bending part and the third bending part are all U-shaped structures.

According to the loop heat pipe provided by the invention, heat emitted by a smart phone is transferred into an evaporator, a liquid working medium in a capillary core absorbs the heat to form steam, the steam enters a steam cavity, the steam in the steam cavity enters a condenser through a first channel and is condensed into liquid, the liquid condensed by the condenser enters a compensation cavity through a second channel, a heat insulation layer is arranged on the cavity wall of the compensation cavity far away from the capillary core, most of the heat emitted by the smart phone cannot be transferred into the compensation cavity, so that the temperature in the compensation cavity is lower, the liquid in the compensation cavity is difficult to boil to generate steam, the liquid in the compensation cavity enters the capillary core, the compensation cavity is difficult to generate steam, the steam cavity can generate a large amount of steam, so that the air pressure in the steam cavity is larger than that of the compensation cavity, the steam in the steam cavity enters the condenser through the first channel, the liquid enters the compensation cavity through the second channel after being condensed into the liquid, the liquid working medium and the steam can be ensured to circularly flow, and the loop heat pipe can continuously operate.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is a schematic structural diagram of a loop heat pipe according to an embodiment of the present invention;

FIG. 2 is an exploded view of a loop heat pipe in an embodiment of the present invention;

FIG. 3 is a cross-sectional view of a loop heat pipe in an embodiment of the invention;

fig. 4 is a schematic structural diagram of a first plate in an embodiment of the present invention.

The main components are as follows:

1. an evaporator; 1.1, a first plate body; 111. a first bent portion; 112. a second bent portion; 113. a third bent portion; 114. the bending part of the first bending part; 115. the bending part of the second bending part; 1.2, a second plate body; 2. a condenser; 3. a second channel; 4. a first channel; 5. a liquid injection port; 6. a capillary core; 7. a heat source; 8. a compensation chamber; 9. a steam chamber.

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without inventive step based on the embodiments of the present invention, are within the scope of protection of the present invention.

It should be noted that all directional indicators (such as up, down, left, right, front, back \8230;) in the embodiments of the present invention are only used to explain the relative positional relationship between the components, the motion situation, etc. in a specific posture (as shown in the attached drawings), and if the specific posture is changed, the directional indicator is changed accordingly.

In addition, the descriptions related to "first", "second", etc. in the present invention are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the feature. In addition, "and/or" in the whole text includes three schemes, taking a and/or B as an example, including a technical scheme, and a technical scheme that a and B meet simultaneously; in addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

As shown in fig. 1 to 3, in some embodiments, a loop heat pipe for dissipating heat of a smart phone includes a first channel 4, a second channel 3, an evaporator 1 and a condenser 2, where the evaporator 1 is configured to absorb heat dissipated by the smart phone, the evaporator 1 includes a casing and a capillary core 6, the capillary core 6 is configured to be filled with a liquid working medium, the casing has a sealed cavity, the capillary core 6 is disposed in the sealed cavity and separates the sealed cavity into a compensation cavity 8 and a vapor cavity 9, a thermal insulation layer is disposed on a cavity wall of the compensation cavity 8 away from the capillary core 6 (that is, the cavity walls in the other compensation cavities are all provided with a thermal insulation layer except the capillary core 6), one end of the first channel 4 is communicated with the vapor cavity 9, and the other end is communicated with the condenser 2, one end of the second channel 3 is communicated with the compensation cavity 8, and the other end is communicated with the condenser 2. It should be noted that the capillary wick 6 is used for gas-liquid separation, and a heat insulating layer cannot be arranged on the surface of the capillary wick 6, which would affect the liquid absorption function of the capillary wick 6. The other side walls, bottom wall and top wall of the compensation chamber 6 are provided with a thermal insulation layer in addition to the side of the capillary wick 6.

The dotted arrows in fig. 1 indicate the flow direction of the vapor, and the solid arrows indicate the flow direction of the liquid. When the intelligent mobile phone heat pump working device works, heat emitted by the intelligent mobile phone is transferred into the evaporator 1, a liquid working medium in the capillary core 6 absorbs the heat to form steam, the steam enters the steam cavity 9, the steam in the steam cavity 9 enters the condenser 2 through the first channel 4 and is condensed into liquid, the liquid condensed by the condenser 2 enters the compensation cavity 8 through the second channel 3, the cavity wall of the compensation cavity 8 far away from the capillary core 2 is provided with a heat insulation layer, most of the heat emitted by the heat source 7 of the intelligent mobile phone cannot be transferred into the compensation cavity 8, so that the temperature in the compensation cavity 8 is low, further the liquid in the compensation cavity 8 is difficult to boil to generate steam, the liquid in the compensation cavity 8 enters the capillary core 6 (the liquid in the compensation cavity 8 enters the capillary core 6 under the action of the capillary force, capillary core 6 has the function of imbibition, the liquid in the compensation chamber 8 is constantly absorbed to capillary core 6, liquid in capillary core 6 can not flow backwards to in the compensation chamber 8 after being heated and evaporated, but get into steam chamber 9), compensation chamber 8 is difficult to produce steam, steam chamber 9 can produce a large amount of steam, so that the atmospheric pressure in steam chamber 9 is greater than the atmospheric pressure of compensation chamber 8, with the steam in the drive steam chamber 9 gets into condenser 2 through first passageway 4, get into compensation chamber 8 through second passageway 3 after the condensation becomes liquid, ensure that liquid working medium and steam can the circulation flow, make the loop heat pipe constantly operate, constantly dispel the heat to the smart mobile phone.

Specifically, the first passage 4 is a vapor pipe, and the second passage 3 is a liquid pipe. The heat insulation layer is high-temperature adhesive tape or a coating with low heat conductivity coefficient. And a high-temperature adhesive tape is pasted or a coating with low thermal conductivity coefficient is sprayed in the compensation cavity 8 in a sputtering way. Low thermal conductivity coatings include, but are not limited to, flame retardants such as epoxies or silicates.

The capillary wick 6 is a curved structure, and the curved capillary wick 6 can increase the contact area between the liquid in the compensation cavity 8 and the capillary wick 6, so that the liquid absorption capacity of the capillary wick 6 can be improved, the liquid absorption resistance of the capillary wick 6 can be reduced, and in addition, the overflow area of the steam after the capillary wick 6 is heated can be increased. The capillary core 6 in the evaporator 1 is a porous structure formed by sintering metal powder such as copper powder, nickel powder, titanium powder and the like, and has good liquid absorption capacity. The capillary core 6 is packaged in the sealed cavity of the evaporator 1, so that the integrated packaging is completed, and the ultrathin loop heat pipe is completed. The width and the thickness of the capillary core 6 are the same as those of the evaporation cavity, so that the good sealing performance of the evaporation cavity 9 and the compensation cavity 8 is ensured, and the liquid in the compensation cavity 8 is prevented from entering the evaporation cavity 9.

Condenser 1 includes condenser apron and condenser bottom plate, processes such as punching press, sculpture, machine tooling at condenser apron surface and processes out a U type passageway, can effectively increase the heat transfer area of steam, is favorable to condensing of steam.

Further, the first channel 4, the second channel 3, the evaporator 1 and the condenser 2 are of an integrally formed structure, and the integrally formed structure is arranged inside the smart phone, so that the loop heat pipe can be stably arranged inside the smart phone.

Furthermore, a steam opening is arranged in the steam cavity 9, the steam opening is communicated with one end, away from the condenser 2, of the first channel 4, a liquid inlet is arranged in the compensation cavity 8, the liquid inlet is communicated with one end, away from the condenser 2, of the second channel 3, and the size of the steam opening is larger than that of the liquid opening, so that the flow resistance of steam is reduced.

One end of the second channel 3, which is close to the compensation chamber 8, is provided with a liquid injection port 5, the liquid injection port 5 is used for allowing an external liquid working medium to enter the compensation chamber 8, and the liquid working medium evaporates and condenses to circularly flow among the first channel 4, the second channel 3, the evaporator 1 and the condenser 2.

In another embodiment, a loop heat pipe includes a capillary core 6, a first plate 1.1, and a second plate 1.2, where the first plate 1.1 is provided with a through groove, the second plate 1.2 covers the first plate 1.1, so that the groove forms a first channel 4 and a second channel 3, a condenser 2 is disposed between a first end of the first channel 4 and a first end of the second channel 3, an accommodating cavity is disposed between a second end of the first channel 4 and a second end of the second channel 3, the capillary core 6 is disposed in the accommodating cavity and separates the accommodating cavity into a compensation cavity 8 and a steam cavity 9, and a heat insulating layer is disposed on a cavity wall of the compensation cavity 8 away from the capillary core 6. First plate body 1.1 and second plate body 1.2 are the flat structure, and first plate body 1.1 and second plate body 1.2 lid are closed the back, realize handling the flattening of loop heat pipe to the structure of adaptation smart mobile phone sets up so, can get rid of unnecessary junction, and first plate body 1.1 and second plate body 1.2 integration set up the risk that can significantly reduce gas leakage, and the leakproofness is good.

The first plate body 1.1 and the second plate body 1.2 are made of brass, phosphor bronze or red copper. The sealed cavity of the first plate body 1.1 is processed by stamping, etching and machining technologies, and the first plate body 1.1 and the second plate body 1.2 are hermetically welded by a laser welding process. The first plate body 1.1 is an upper cover plate, and the second plate body 1.2 is a lower bottom plate.

The surface of the first plate body 1.1 is processed into an ultrathin cavity through processes of stamping, etching or machining and the like, the thickness of the cavity is smaller than 1mm, the cavity is used for placing the capillary core 6, and the periphery of the first plate body 1.1 is provided with a skirt edge for sealing and welding the first plate body 1.1 and the second plate body 1.2.

Specifically, as shown in fig. 4, the first plate body 1.1 includes a first bending portion 111, a second bending portion 112 and a third bending portion 113, a first end of the first bending portion 111 is connected to a first end of the second bending portion 112, a second end of the first bending portion 111 is connected to a first end of the third bending portion 113, a second end of the second bending portion 112 is connected to a second end of the third bending portion 113, the first channel 4 is disposed on the first bending portion 111, the second channel 3 is disposed on the second bending portion 112, and the capillary core 6 is disposed on the third bending portion 113. The bent part 114 of the first bending part is used for installing a space of a camera of a smart phone. The space that the department 115 of buckling of second kink is used for installing the smart mobile phone battery, and the structure of first plate body 1.1 and second plate body 1.2 designs based on the inner structure of the smart mobile phone on the existing market arranges, reserves sufficient space for parts such as inside battery of smart mobile phone and camera.

More specifically, the first bending part 111, the second bending part 112, and the third bending part 113 are all U-shaped structures.

The working principle is as follows:

as shown in fig. 3, a proper amount of liquid working medium is injected into the compensation chamber 8 and the liquid pipeline through the liquid injection port 5, the lower end region of the capillary wick 6 serves as the compensation chamber 8, so that the liquid absorption resistance of the capillary wick 6 can be effectively reduced, heat insulation treatment is performed in the region of the compensation chamber 8, the temperature of liquid inside the compensation chamber 8 is reduced, steam generated by boiling of the compensation chamber 8 is reduced, a winding structure is designed at the upper end of the capillary wick 6, so that the discharge area of the steam of the capillary wick 6 is effectively increased, steam blockage is avoided, an obvious temperature difference is formed at two sides of the capillary wick 6, the compensation chamber 8 can continuously provide liquid for the capillary wick 6 to absorb, the liquid inside the capillary wick 6 is heated and evaporated, the generated steam is continuously discharged from the region of the steam chamber 9, enters the condenser 2 along the steam pipeline, the steam condenses into liquid in the condenser 2, and returns to the region of the compensation chamber 8 of the evaporator 1 along the liquid pipeline, the capillary wick 6 continues to absorb and exchange heat, heat in the region of the compensation chamber 8, heat insulation treatment can be avoided by utilizing the difference in temperature, so that the pressure balance between the capillary wick 6 and the steam loop can be further, and the problem that the heat pipe cannot be effectively solved.

The water absorption of the capillary core 6 and the heat insulation treatment inside the compensation cavity 8 enable liquid inside the capillary core 6 to be heated and evaporated preferentially, steam enters the steam channel along one side of the steam cavity 9, steam is difficult to generate due to the fact that the temperature is low on one side of the compensation cavity 8, temperature difference is formed on two sides, and operation of the loop heat pipe is promoted. Steam in the steam cavity 9 enters the condenser 2 along a steam pipeline, and after the steam is condensed, the steam returns to the compensation cavity 8 along a liquid pipeline, so that circulation is completed, and the problem that the steam cannot be started and operated is effectively solved. The loop heat pipe has the advantages of miniaturization, ultra-thinness, light weight and the like, and can well meet the heat dissipation requirement of narrow space in electronic equipment such as mobile wearing and the like.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. The utility model provides a loop heat pipe dispels the heat to smart mobile phone which characterized in that includes:

a first channel;

a second channel;

the evaporator is used for absorbing heat emitted by the smart phone and comprises a shell and a capillary core, the capillary core is used for filling a liquid working medium, the shell is provided with a sealed cavity, the capillary core is arranged in the sealed cavity and isolates the sealed cavity into a compensation cavity and a steam cavity, and a heat insulation layer is arranged on the cavity wall of the compensation cavity, which is far away from the capillary core; and

2. A loop heat pipe according to claim 1, wherein the heat insulating layer is a high temperature tape.

3. A loop heat pipe according to claim 1 wherein the thermal insulation layer is a low thermal conductivity coating.

4. A loop heat pipe as claimed in claim 1 wherein said first passage, said second passage, said evaporator and said condenser are of unitary construction.

5. A loop heat pipe according to claim 1 wherein a vapor opening is provided in the vapor chamber, the vapor opening communicating with an end of the first passage remote from the condenser, the compensation chamber being provided with a liquid inlet communicating with an end of the second passage remote from the condenser, the vapor opening being larger in size than the liquid opening.

6. A loop heat pipe according to claim 1, wherein the wick is a meander-like structure.

7. A loop heat pipe as claimed in claim 1, wherein an end of said second channel adjacent to said compensation chamber is provided with a liquid injection port for external liquid working medium to enter into said compensation chamber.

8. A loop heat pipe, comprising: capillary core, first plate body and second plate body, the recess that switches on is seted up to the first plate body, the first plate body with second plate body lid closes, so that the recess forms first passageway and second passageway the first end of first passageway with be provided with the condenser between the first end of second passageway the second end of first passageway with be provided with the holding chamber between the second end of second passageway, the capillary core set up in the holding chamber, and will the holding chamber is kept apart into compensation chamber and steam chamber, the compensation chamber is kept away from the chamber wall of capillary core is provided with the heat insulation layer.

9. A loop heat pipe according to claim 8, wherein the first plate body comprises a first bent portion, a second bent portion and a third bent portion, a first end of the first bent portion is connected to a first end of the second bent portion, a second end of the first bent portion is connected to a first end of the third bent portion, a second end of the second bent portion is connected to a second end of the third bent portion, the first channel is disposed on the first bent portion, the second channel is disposed on the second bent portion, and the capillary wick is disposed on the third bent portion.

10. A loop heat pipe according to claim 9, wherein the first bent portion, the second bent portion, and the third bent portion are all U-shaped structures.