Heat-pipe engine structure

Abstract

A heat-pipe engine structure applicable to heat-exchange system. The heat-pipe engine structure includes a metal mesh laminate composed of more than two metal meshes which are tightly laminated with each other to form numerous meshes several times the unlaminated meshes of any original metal mesh. An upper metal film and a lower metal film are respectively bonded to upper and lower faces of the metal mesh laminate. The peripheries of the metal films are sealed to form a housing enclosing the metal mesh laminate. The meshes of the metal mesh laminate form a first nature vapor chamber. A liquid ingress and a vapor egress are formed on the periphery of the housing in different positions for externally connecting with a circulating loop to form a loop heat-pipe for one-way circulation of incoming liquid and outgoing vapor. The meshes of the metal mesh laminate are densely and evenly distributed in as the porous space in the housing for effectively conducting the working fluid to achieve better heat evaporation effect. In heat-exchange procedure, the working fluid is quickly changed between two phases to enhance the circulation. The laminated porous meshes form enough capillary pressure that meniscus in the engine wick supports enough pressure to overcome total system pressure drops from loop.

Description

BACKGROUND OF THE INVENTION

[0001] The present invention is related to a heat-pipe engine structure applicable to heat-exchange system. The heat-pipe engine structure includes a metal mesh laminate composed of more than two metal meshes which are tightly laminated with each other to form numerous meshes several times the meshes of any original metal mesh. An upper metal film and a lower metal film are respectively bonded to upper and lower faces of the metal mesh laminate. The peripheries of the metal films are sealed to form a housing enclosing the metal mesh laminate. A working fluid is contained in at least a part of the meshes. The fluid-less meshes naturally form vapor chambers communicating with each other. The meshes of the metal mesh laminate are densely and evenly distributed for effectively conducting the working fluid to enhance evaporation effect. In heat-exchange procedure, the working fluid is quickly changed between two phases that enhance the circulation and heat-exchange effect by P-drops on loop. In addition, the heat-pipe engine has flat structure and can be made with lightweight and minitype for wider application. A liquid ingress and a vapor egress are formed on the housing of the heat-pipe engine in different positions for externally connecting with a circulating loop to form a loop heat-pipe for one-way circulation of incoming liquid and outgoing vapor. Accordingly, a better heat conduction effect can be achieved.

[0002] U.S. Pat. No. 4,515,209 discloses a conventional flow conducting device for dissipation. The flow conducting device is composed of an evaporator and a condenser connected with each other by a loop. By means of the evaporator, the liquid in the flow conducting device is heated and evaporated into vapor which flows through the loop into the condenser. The condenser dissipates heat to condense vapor into liquid. The liquid is transferred to the evaporator through another loop to absorb heat and evaporate.

[0003] According to the above procedure, the working fluid is circularly changed between two phases to achieve heat dissipation effect.

[0004] However, the above structure has some shortcomings as follows:

[0005] 1. The capillary necessary for the operation of the evaporator is achieved by a porous structure formed in the evaporator by means of powder metallurgy. The sizes of the voids in the evaporator cannot be unified. Therefore, it is hard to truly effectively conduct the fluid to change between two phases.

[0006] 2. The evaporator and the condenser are designed with vertical or cylindrical pattern. Due to gravity, such design limits the application of the evaporator and the condenser. Such design tends to seriously interfere with horizontal flowing of the fluid.

[0007] 3. The porous structure is formed in the evaporator by means of powder metallurgy. The outer layer of the evaporator can hardly have a flat pattern for snugly contacting with the electric element (chip). Therefore, the heat conduction efficiency is lowered. Moreover, the difficulty in processing and cost for the processing are higher. This is not so cost-effective.

[0008] 4. The meniscus in the evaporator wick result capillary pressure will equal to the total system pressure drop, but powder metallurgy process also disturb the outgas process, that is, it can not be mass-produced for outgas process with powder metallurgy. The gas will increase the pressure drop to have system primary fail.

[0009] 5. The porous structure formed by means of powder metallurgy generally can hardly have even structural characteristics after sintered. Therefore, it is hard to mass-produce the products with unified quality. Furthermore, it is hard to control the thickness of the housing structure and the distribution of the internal powder is more complicated. Therefore, the yield is low.

[0010] With respect to conventional micro-loop heat pipe, a representative monograph published by NASA Goddard Space Flight Center, Mr. Jentung Ku discloses that the conventional loop heat pipe (LHP) is structurally designed with a reservoir or compensation chamber for reserving a certain amount of working fluid. Therefore, the evaporator can be supplemented with a proper amount of fluid. Also, the gas or bubble is further filtered to avoid interference of the gas or bubble with the working fluid.

[0011] In addition, the design of conventional LHP is biased to high power (W). The design of system reaction efficiency is often neglected. Almost all relevant publications teach that temperature hysteresis and overshoot will take place when activated. Such structural design leads to limitation of design of evaporator and reservoir or compensation chamber. While successfully challenging high power, it is impossible to mobilely deal with various heat changes. Therefore, such structure has poor presentation in thermodynamics, especially low-power thermodynamics.

[0012] With respect to the application of an existent CPU, the CPU cannot accept the heat cooler which can only deal with 200 W heat dissipation, while being unable to solve 20 W problem. However, the CPU used in ordinary industry or aeronautic/space field can accept this.

[0013] The design of conventional LHP is directed to forced convection. The change of room temperature will inevitably affect the effect.

[0014] FIG. 1 shows a conventional flow conducting device. An upper metal film 11 and a lower metal film 12 are tightly mated with each other to form a housing 10. The inner wall faces 110, 120 of the upper and lower metal films 11, 12 are sintered with particles 121 by means of powder metallurgy to form capillary passage. A fluid 14 is filled in the housing 10. When one end of the housing 10 contacts with a heat source 20, the fluid 14 is evaporated to flow through the capillary passage to the other end in contact with a heat cooler (not shown). The heat of the vapor is dissipated by the heat cooler so that the vapor is condensed and liquidized into the liquid. The liquid flows back to the evaporator on the heat source 20 for absorbing heat thereof to complete a cycle. The change between two phases can achieve the heat dissipation effect. However, the above arrangement still has some shortcomings as follows:

[0015] 1. The heat conductor is sintered by means of powder metallurgy. Therefore, the heat conductor must have a considerable thickness. Otherwise, the heat conductor tends to deform.

[0016] 2. When sintering the metal particles, the particles can be hardly evenly distributed. Therefore, the quality of the product cannot be unified.

[0017] 3. The heat conductor has a considerable thickness so that the internal space is relatively reduced. Only little amount of fluid can be filled in the housing. Therefore, the heat conduction effect can be hardly enhanced. Moreover, the thick heat conductor causes unexpected heat transfer. The unexpectedly evaporized wick reduces the heat evaporating effect.

[0018] 4. The heat conductor lacks vapor chamber design. Therefore, the heat conductor can hardly receive the pressure of saturated vapor generated after the working fluid absorbs the heat. As a result, the temperature is apt to abruptly increase and the heat dissipation effect is poor.

[0019] 5. The heat conductor is a closed system. The change between two phases takes place inside one single heat conductor. The total two-way heat-exchange area is simply up to the area of the single heat conductor. Therefore, the heat dissipation effect is quite limited.

SUMMARY OF THE INVENTION

[0020] It is therefore a primary object of the present invention to provide a heat-pipe engine with porous structure. The heat-pipe engine structure includes a metal mesh laminate composed of at least two metal meshes enclosed in a housing. The metal mesh laminate forms a micro-porous structure having numerous meshes which are evenly densely distributed in the housing. The fluid is evenly contained in at least a part of the meshes of the metal mesh laminate for more effective heat-exchange. Therefore, the working fluid is more quickly changed between two phases. In addition, the heat-pipe engine has flat structure and can be made with lightweight and minitype for wider application. A liquid ingress and a vapor egress are formed on the housing of the heat-pipe engine in different positions for externally connecting with a loop heat-pipe for one-way circulation of incoming liquid and outgoing vapor. Accordingly, a better heat conduction effect can be achieved.

[0021] It is a further object of the present invention to provide the above heat-pipe engine in which the housing is formed with another vapor chamber. When the working fluid is heated and evaporated, the vapor will not be compressed to create too high saturation pressure which will hinder the internal fluid from horizontally circulating. In other words, a chamber space is reserved between the egress of the housing and the metal mesh laminate for receiving the expanded volume of the saturation vapor transformed from the instantaneously boiled liquid. Therefore, the meniscus in the engine wick will result enough capillary pressure to have the saturated vapor prime into the loop by egress, so that the working fluid can more smoothly flow through the housing to enhance the heat conduction effect.

[0022] It is still a further object of the present invention to provide the above heat-pipe engine structure which is applicable to heat-exchange system. A liquid ingress and a vapor egress are formed on the housing of the heat-pipe engine for externally connecting with a circulating loop to form a loop heat-pipe for one-way circulation of incoming liquid and outgoing vapor. This eliminates the shortcoming of energy loss of the reciprocally circular heat-exchange of the conventional heat-pipe.

[0023] The present invention can be best understood through the following description and accompanying drawings wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG. 1 is a perspective exploded view of a conventional flow conducting structure;

[0025] FIG. 2 is a perspective assembled view of the heat-pipe engine of the present invention;

[0026] FIG. 3 is a perspective exploded view of the heat-pipe engine of the present invention;

[0027] FIG. 4 is a sectional view of the flow conducting structure of the present invention;

[0028] FIG. 4A is an enlarged view of circled area A of FIG. 4;

[0029] FIG. 5 is a sectional view of another embodiment of the present invention;

[0030] FIG. 6 is a perspective view of still another embodiment of the present invention;

[0031] FIG. 7 is a sectional view of the embodiment of the present invention according to FIG. 6; and

[0032] FIG. 8 is a perspective sectional view of the embodiment of the present invention according to FIG. 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Please refer to FIGS. 2, 3 and 4. The heat-pipe engine of the present invention includes a housing 10, a metal mesh laminate 13, a fluid 14 and a vapor chamber 15A.

[0034] The metal mesh laminate 13 is formed of one single metal mesh folded into multiple layers. Alternatively, the metal mesh laminate 13 can be composed of more than two metal meshes 131 which are tightly laminated with each other. The metal mesh 131 is formed of metal wires which longitudinally and transversely intersect each other to evenly form numerous meshes. After the metal meshes are laminated, more or several times meshes will be formed between the laminated metal meshes.

[0035] The housing 10 is composed of an upper metal film 11 and a lower metal film 12. The peripheries of the upper and lower metal films 11, 12 are connected and sealed. The upper and lower metal films 11, 12 are respectively bonded to and connected with upper and lower faces of the metal mesh laminate 13. After the peripheries of the upper and lower metal films 11, 12 are sealed, the metal mesh laminate 13 is snugly enclosed in the housing 10. The metal films 11, 12 can be flexible as necessary for snugly contacting with different configuration of heat source 20. In addition, the interior of the housing 10 can be vacuumed as necessary to enhance the flowing and circulating ability of the working fluid.

[0036] The fluid 14 is contained in a part of meshes 1311 of the metal mesh laminate. The other meshes 1311 free from the fluid 14 serve as a first vapor chamber 15A.

[0037] The housing 10 of the heat-pipe engine is filled with the working fluid 14 necessary for heat conduction. When one end of the housing 10 contacts with a heat source 20, the working fluid 14 in the housing 10 will quickly evaporate. At this time, the first vapor chamber 15A of the meshes 1311 serves as a capillary passage for the vapor to flow to the other end of the housing 10. The other end of the housing 10 contacts with the heat-dissipating body 30 which radiates the heat of the evaporated working fluid and changes the phase of the vapor back into the liquid working fluid. Then the fluid flows through the meshes 1311 back to the end contacting with the heat source 20. Accordingly, the working fluid 14 in the housing 10 can quickly absorb heat and dissipate heat and change between two phases. Therefore, the heat dissipation effect can be effectively achieved.

[0038] FIG. 5 shows another embodiment of the present invention, which has another vapor chamber. After the housing 10 of the heat-pipe engine is sealed, the metal mesh laminate 13 is enclosed in the housing 10. A second vapor chamber 15B free from the metal mesh laminate is defined between the metal mesh laminate 13 and an egress 16 of the periphery of the housing 10. The vapor generated when the working fluid 14 is heated and evaporated can easily flow into the vapor chambers 15A, 15B. By means of the second vapor chamber 15B, the vapor is prevented from being compressed to create too high saturation pressure which will hinder the internal fluid from horizontally circulating without gravity.

[0039] FIGS. 6, 7 and 8 show still another embodiment of the heat-pipe engine of the present invention. A certain section of the periphery of the housing 10 is formed with a vapor egress 16 at the second vapor chamber 15B. A liquid ingress 17 is formed on another section of the periphery of the housing 10 corresponding to the metal mesh laminate 13. An external loop 18 is additionally connected between the vapor egress 16 and the liquid ingress 17. The loop 18 contacts with a heat-dissipating body 30.

[0040] By means of the heat-dissipating body 30 in contact with the loop 18, the heat of the evaporated working fluid 14 flowing in vapor state in the loop 18 can be fully dissipated to change the phase into liquid. The working fluid 14 will flow from the liquid ingress 17 into the engine housing 10. When the working fluid 14 flows through the engine housing 10, the upper end of which is in contact with the heat source 20, via the dense meshes 1311 of the metal mesh laminate 13, heat-exchange takes place between the heat source 20 and the fluid 14 so that the fluid 14 can quickly absorb the heat from the heat source 20 to evaporate. The vapor flows through the capillary passage of the first vapor chamber 15A formed of the meshes 1311 to the second vapor chamber 15B. Then the evaporated working fluid 14 further flows through the vapor egress 16 into the loop 18. Via the loop 18, the evaporated working fluid 14 is repeatedly circulated to the heat-dissipating body 30 for heat dissipation. Then the vapor is restored into the liquid working fluid 14. By means of the heat-exchange between the circulated working fluid 14 and the engine housing 10 and the heat-dissipating body 30, a high heat dissipation effect can be achieved.

[0041] In conclusion, according to the above arrangement, multiple metal meshes are laminated to form a metal mesh laminate having evenly dense meshes. The metal mesh laminate forms a porous structure. Each unit mesh has even voids to create equal hydrophilic force. Therefore, the stability of the fluid in the flow conducting system is enhanced. Moreover, the liquid working fluid and vapor working fluid contained in the structure are separated. Therefore, the liquid backflow and the vapor will not interfere with each other to avoid mixture of vapor and liquid. This eliminates the shortcomings of the conventional heat-pipe.

[0042] The above embodiments are only used to illustrate the present invention, not intended to limit the scope thereof. Many modifications of the above embodiments can be made without departing from the spirit of the present invention.

Claims

What is claimed is:

1. A heat-pipe engine structure comprising: a metal mesh laminate composed of more than two metal meshes each having many meshes, the metal meshes being tightly laminated with each other to form numerous meshes in the metal mesh laminate, which are more than the meshes of any original metal mesh; a housing composed of an upper metal film and a lower metal film peripheries of which are connected and sealed, the upper and lower metal films being respectively positioned on upper and lower faces of the metal mesh laminate, whereby after the peripheries of the upper and lower metal films are sealed, the metal mesh laminate is snugly enclosed in the housing, the porous meshes of the metal mesh laminate forming vapor chambers; and a fluid contained in a part of the meshes of the metal mesh laminate.

2. The heat-pipe engine structure as claimed in claim 1, wherein the metal mesh laminate is formed of one single metal mesh folded into multiple layers.

3. The heat-pipe engine structure as claimed in claim 1, wherein each of the metal meshes of the metal mesh laminate has meshes of the same size.

4. The heat-pipe engine structure as claimed in claim 2, wherein each of the metal meshes of the metal mesh laminate has meshes of the same size.

5. The heat-pipe engine structure as claimed in claim 1, wherein the periphery of the housing is formed with at least one liquid ingress and at least one vapor egress for externally connecting with a circulating loop.

6. The heat-pipe engine structure as claimed in claim 2, wherein the periphery of the housing is formed with at least one liquid ingress and at least one vapor egress for externally connecting with a circulating loop.

7. The heat-pipe engine structure as claimed in claim 5, wherein a heat-dissipating body is connected with the circulating loop.

8. The heat-pipe engine structure as claimed in claim 6, wherein a heat-dissipating body is connected with the circulating loop.

9. A heat-pipe engine structure comprising: a metal mesh laminate composed of more than two metal meshes each having many meshes, the metal meshes being tightly laminated with each other to form numerous porous meshes in the metal mesh laminate, which are more than the meshes of any original metal mesh; and a housing composed of an upper metal film and a lower metal film peripheries of which are connected and sealed, the upper and lower metal films being respectively positioned on upper and lower faces of the metal mesh laminate, whereby after the peripheries of the upper and lower metal films are sealed, the metal mesh laminate is snugly enclosed in the housing, the meshes of the metal mesh laminate forming a nature vapor chamber, at least one second vapor chamber free from the metal mesh laminate being defined between the metal mesh laminate and the periphery of the metal films.

10. The heat-pipe engine structure as claimed in claim 9, wherein at least one liquid ingress is formed on a section of the periphery of the housing corresponding to the metal mesh laminate and a vapor egress is formed on a section of the periphery of the housing corresponding to the second vapor chamber for externally connecting with a circulating loop.

11. The heat-pipe engine structure as claimed in claim 9, wherein the metal mesh laminate is formed of one single metal mesh folded into multiple layers.

12. The heat-pipe engine structure as claimed in claim 10, wherein the metal mesh laminate is formed of one single metal mesh folded into multiple layers.

13. The heat-pipe engine structure as claimed in claim 9, wherein each of the metal meshes of the metal mesh laminate has meshes of the same size.

14. The heat-pipe engine structure as claimed in claim 10, wherein each of the metal meshes of the metal mesh laminate has meshes of the same size.

15. The heat-pipe engine structure as claimed in claim 9, wherein the periphery of the housing is formed with at least one vapor egress and at least one liquid ingress, an external circulating loop being connected between the vapor egress and the liquid ingress.

16. The heat-pipe engine structure as claimed in claim 10, wherein the periphery of the housing is formed with at least one vapor egress and at least one liquid ingress, an external circulating loop being connected between the vapor egress and the liquid ingress.

17. The heat-pipe engine structure as claimed in claim 15, wherein a heat-dissipating body is connected with the circulating loop.

18. The heat-pipe engine structure as claimed in claim 16, wherein a heat-dissipating body is connected with the circulating loop.