KR100633922B1 - Flat Plate Heat Transferring Apparatus - Google Patents

Abstract

The present invention relates to a plate heat transfer apparatus. The present invention is provided between a heat source and a heat dissipation unit, a heat conductive plate-shaped case accommodating while absorbing heat from the heat source and condensed while releasing heat from the heat dissipation unit; And a mesh layer assembly installed in the plate-shaped case and having a structure in which a dense mesh layer providing a flow path of the liquid refrigerant and a coarse mesh layer providing the flow path of the liquid refrigerant and the diffusion path of the vapor phase refrigerant at the same time. Include. In some cases, the coarse mesh layer and the dense mesh layer may be alternately stacked alternately, and the dense mesh layer may be replaced with a wick structure. Preferably, the sparse mesh layer is a screen mesh having a mesh wire diameter of 0.2 mm or more and 0.4 mm or less, and a mesh number of 10 or more and 20 or less.

According to the present invention, it is possible to supply the condensed refrigerant to the heat source quickly and smoothly, to cause the vaporization and diffusion of the refrigerant at the same time, and in particular to ensure a large surface area for vaporization and condensation, The heat transfer performance of the plate heat transfer apparatus is increased.

Description

Flat Plate Heat Transferring Apparatus

The following drawings attached to this specification are illustrative of preferred embodiments of the present invention, and together with the detailed description of the invention to serve to further understand the technical spirit of the present invention, the present invention is a matter described in such drawings It should not be construed as limited to.

1 is a cross-sectional view of a plate heat transfer device according to the prior art.

2 is a cross-sectional view of a plate heat transfer apparatus according to a first embodiment of the present invention.

3 is a grid plan view of a mesh layer constituting the mesh layer assembly according to the first embodiment of the present invention.

4 is a cross-sectional view taken along line AA ′ of FIG. 3.

FIG. 5 is a view illustrating a state in which adjacent dense mesh layers and liquid films existing in a coarse mesh layer are connected to each other in the mesh layer assembly according to the first embodiment of the present invention.

FIG. 6 is a view illustrating a liquid film formed at an intersection point of mesh wires in a coarse mesh layer according to a first embodiment of the present invention.

7 is a cross-sectional view of a plate heat transfer apparatus according to a second embodiment of the present invention.

8 to 10 are cross-sectional views of apparatuses showing various modifications of the mesh layer assembly of the present invention.

11 to 13 are perspective views of a plate heat transfer apparatus according to an embodiment of the present invention.

14 to 16 are sectional views showing the configuration of a plate-shaped case according to an embodiment of the present invention.

The present invention relates to a plate heat transfer apparatus capable of releasing heat from a heat source through circulation of a refrigerant through vaporization and condensation of a refrigerant. More particularly, the present invention relates to a plate heat transfer apparatus that can be made extremely thin while having an excellent heat transfer and heat diffusion structure. will be.

In recent years, electronic devices such as notebook computers and PDAs have become smaller and smaller in thickness due to the development of high integration technology. In addition, as the demand for high responsiveness and function improvement of electronic equipment increases, power consumption is also gradually increasing. Accordingly, a lot of heat is generated from the electronic components therein during the operation of the electronic equipment, various plate heat transfer devices are used to release the heat to the outside.

Representative examples of the conventional plate heat transfer apparatus include a heat pipe sealed after depressurizing a plate metal case in a vacuum state and injecting a refrigerant.

When the heat pipe is installed such that a portion of the heat pipe is in contact with an electronic component (heat source) that generates heat, the refrigerant near the heat source is heated to vaporize and diffuses into a relatively low temperature region. The vaporized refrigerant then condenses again, releasing heat to the outside, becoming a liquid state and returning to its original position. As described above, heat generated from the heat source is released to the outside by the circulation mechanism of the refrigerant inside the plate-shaped metal case, thereby maintaining the temperature of the electronic component at an appropriate line.

FIG. 1 illustrates a conventional plate-shaped heat transfer device 10 installed between the heat source 20 and the heat sink 30 to transfer heat from the heat source 20 to the heat sink 30 in more detail.

Referring to the drawings, the conventional plate heat transfer device 10 is made of a metal case 50 in which a refrigerant is filled in the interior 40. In addition, a wick structure 60 is formed on an inner surface of the metal case 50 to provide an efficient circulation mechanism of the refrigerant.

The heat generated from the heat source 20 is transferred to the wick structure 60 inside the plate heat transfer device 10 in contact with the heat source 20. Then, the refrigerant contained in the wick structure 60 (functioning as a 'coolant vaporization portion') directly above the heat source 20 is vaporized and diffused in all directions through the internal space 40, and then the heat sink 30. The heat dissipates and condenses in the wick structure 60 (functioning as a 'coolant condensation unit') directly below. The condensed refrigerant is contained in the wick structure 60 and then returned to the refrigerant vaporization unit by capillary force. When the temperature of the heat source 20 is higher than the vaporization temperature of the refrigerant, the refrigerant is evaporated again to diffuse, condense, and return. Done. The heat released during the condensation of the refrigerant is transferred to the heat sink 30 and is discharged to the outside by a forced convection method by the fan 70.

In order to increase the heat transfer performance of the plate heat transfer device 10, a large amount of refrigerant must be circulated per unit time. To this end, a large surface area for vaporization and condensation of the refrigerant must be secured, and a vapor passage through which the vaporized refrigerant can be efficiently diffused and a liquid passage through which the condensed refrigerant can flow near the heat source 20 as soon as possible. Should be.

However, in the conventional plate heat transfer apparatus 10, since the surface on which the refrigerant may be vaporized or condensed is limited only to the inner surface of the metal case 50 facing the heat source 20 or the heat sink 30, vaporization of the refrigerant or There is a limit to securing a large surface area for condensation.

In addition, in the conventional plate heat transfer apparatus 10, the condensed refrigerant is contained in the concave-convex of the wick structure 60 provided on the inner surface of the metal case 50 and flows to the refrigerant vaporization portion by capillary force. That is, the flow path through which the condensed refrigerant may flow is limitedly formed along the inner surface of the metal case 50.

Accordingly, the flow distance of the condensed refrigerant through the liquid passage reaches several times the flow distance of the vaporized refrigerant through the vapor passage, so that the return time of the condensed refrigerant is much longer than the diffusion time of the vaporized refrigerant. As such, when there is a large time difference between the return of the condensation refrigerant and the diffusion of the vaporized refrigerant, the flow rate of the refrigerant that can be circulated per unit time decreases accordingly, thereby causing a problem that the heat transfer performance of the plate heat transfer device also decreases. .

Furthermore, since the inside of the plate heat transfer apparatus 10 is in a reduced pressure with a substantially vacuum, there is a side that is vulnerable to external mechanical shock. Therefore, if a mechanical shock is applied during the manufacture or handling of the plate heat transfer device 10, the metal case 50 may be crushed.

Therefore, the present invention was devised to solve the above-mentioned problems of the prior art, and in order to maximize the heat transfer performance of the plate heat transfer device, the flow distance of the condensation refrigerant is reduced, and the flow of the liquid refrigerant and the flow of the gaseous refrigerant are simultaneously induced. Therefore, to maintain the heat transfer mechanism of the plate heat transfer device as it is to introduce a structure that can increase the mechanical strength of the device to the plate heat transfer device.

Another object of the present invention is to provide a plate heat transfer apparatus having a geometry that can maximize heat transfer efficiency by vaporizing and condensing a larger amount of refrigerant.

The plate heat transfer device according to an aspect of the present invention for achieving the above technical problem, is installed between the heat source and the heat dissipation unit, the refrigerant is evaporated while absorbing heat from the heat source and condensed while releasing heat from the heat dissipation unit A thermally conductive plate-shaped case accommodated therein; And a wick structure that is installed inside the plate-shaped case and provides a flow path of the liquid refrigerant by capillary force and a coarse mesh layer that simultaneously provides a flow path of the liquid refrigerant by capillary force and a diffusion path of the gaseous refrigerant. Including the mesh layer assembly having a laminated structure; wherein, the sparse mesh layer is characterized in that the wire diameter is 0.2mm or more and 0.4mm or less, the number of mesh is 10 or more and 20 or less.

Preferably, the coarse mesh layer provides a path through which the liquid refrigerant can flow in the horizontal and vertical directions by capillary force. In addition, the coarse mesh layer is preferably composed of a metal material for improving heat transfer performance.

Optionally, the mesh layer assembly may further include another wick structure in contact with the coarse mesh layer so as to face the wick structure with the coarse mesh layer interposed therebetween.

In the present invention, the wick structure may be produced by sintering copper, stainless, aluminum or nickel powder, or may be produced by etching a polymer, silicon, silica (SiO ₂ ), copper plate, stainless steel, nickel or aluminum plate. have.

Alternatively, the wick structure may be replaced with a dense mesh layer having a larger mesh number and a smaller wire diameter than the coarse mesh layer. In this case, the dense mesh layer is woven from mesh wire having a diameter of 0.03 mm or more and 0.13 mm or less, or a screen mesh having a mesh number of 80 or more and 400 or less.

Plate heat transfer apparatus according to another aspect of the present invention for achieving the above technical problem, is installed between the heat source and the heat dissipating unit, the refrigerant is evaporated while absorbing heat from the heat source and condensed while releasing heat from the heat dissipating unit A thermally conductive plate-shaped case accommodated therein; And a mesh layer assembly installed inside the plate-shaped case and having a structure in which a dense mesh layer and a coarse mesh layer are alternately stacked repeatedly.

Preferably, the dense mesh layer and the coarse mesh layer are alternately stacked to contact each other. And the coarse mesh layer and the dense mesh layer are preferably woven from mesh wire made of metal, polymer, plastic or fiberglass.

An example of the mesh layer assembly structure may be a structure in which a dense mesh layer, a coarse mesh layer, a dense mesh layer, a coarse mesh layer, and a dense mesh layer are stacked in order from the bottom to the top.

Another example of the mesh layer aggregate structure may be a structure in which a dense mesh layer, a coarse mesh layer, a dense mesh layer, and a coarse mesh layer are stacked in order from the bottom to the top.

Another example of the mesh layer aggregate structure may be a structure in which two or more dense mesh layers, a coarse mesh layer, a dense mesh layer, and a coarse mesh layer are stacked in order from top to bottom.

Another example of the mesh layer aggregate structure may be a structure in which two or more dense mesh layers, a coarse mesh layer, a dense mesh layer, a coarse mesh layer, and two or more dense mesh layers are stacked in order from bottom to top. Can be.

The plate heat transfer apparatus according to another aspect of the present invention for achieving the above technical problem, is installed between the heat source and the heat dissipation unit, and is condensed while absorbing heat from the heat source to evaporate and release heat from the heat dissipation unit A thermally conductive plate-shaped case containing a refrigerant; And a wick structure that is installed inside the plate-shaped case and provides a flow path of the liquid refrigerant by capillary force and a coarse mesh layer that simultaneously provides a flow path of the liquid refrigerant by capillary force and a diffusion path of the gaseous refrigerant. It characterized in that it comprises a; mesh layer assembly having a structure that is alternately stacked repeatedly.

In the present invention, the plate-shaped case may be made of a metal, a conductive polymer, a metal coated with a conductive polymer or a conductive plastic, or may be made of an electrolytic copper foil. In the latter case, the uneven surface of the electrolytic copper foil preferably constitutes the inner surface of the case. The sealing of the plate-shaped case may be made by laser welding, plasma welding, TIG welding, ultrasonic welding, brazing bonding, soldering bonding or thermocompression lamination.

In the present invention, the refrigerant injected into the plate-shaped case may be water, methanol, ethanol, acetone, ammonia, CFC-based refrigerant, HCFC-based refrigerant, HFC-based refrigerant or a mixed refrigerant thereof.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the present specification and claims should not be construed as being limited to the common or dictionary meanings, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiments of the present invention and do not represent all of the technical idea of the present invention, various equivalents that may be substituted for them at the time of the present application It should be understood that there may be water and variations.

Plate heat transfer apparatus 100 according to the first embodiment of the present invention, as shown in Figure 2, the plate-shaped case 130 is installed between the heat source 110 and the heat dissipation unit 120, such as a heat sink, and It includes a mesh layer assembly 140 composed of a plurality of mesh layers inserted into the case 130. Inside the plate-shaped case 130, the refrigerant generated by absorbing and evaporating heat generated from the heat source 110 and dissipating heat to the heat dissipation unit 120 is injected.

The mesh layer assembly 140 includes a dense mesh layer 140a, a coarse mesh layer 140b, and a dense mesh layer 140a. The dense mesh layers 140a and 140b face each other while forming a contact interface with the coarse mesh layer 140b.

As shown in FIG. 3, the dense mesh layer 140a and the coarse mesh layer 140b may be screen meshes woven so that the horizontal wire 160a and the vertical wire 160b alternate with each other up and down. Here, the vertical wires 160b refer to mesh wires arranged in the longitudinal direction when the mesh layer is woven, and the horizontal wires 160a refer to mesh wires arranged in the vertical direction with respect to the vertical wires 160b.

The mesh wires 160a and 160b are made of any one of metal, polymer, glass fiber, or plastic. However, since the metal has better heat transfer performance than other materials, it is preferable to adopt a mesh wire of the mesh layers 140a and 140b in terms of heat transfer efficiency. Preferably, the metal is any one of copper, aluminum, stainless steel or molybdenum or alloys thereof.

Referring to FIG. 3, the width a of the empty space existing in the unit grid of the mesh layers 140a and 140b is generally expressed as Equation 1 below. The width a is a major parameter in determining the functional characteristics of the mesh layers 140a and 140b.

a = (1-Nd) / N

Where d is the diameter of the mesh wire in inches and N is the number of lattice meshes that are 1 inch in length. For example, if N is 100, there are 100 mesh grids that are 1 inch long.

When the temperature of the heat source 110 is lower than the vaporization temperature of the refrigerant, and thus the device 100 does not perform heat transfer, the physically adsorbed refrigerant is formed at the intersection of the wires and the surfaces of the wires forming the mesh layers 140a and 140b. exist. In the case of the coarse mesh layer 140b, all of the empty spaces of the mesh lattice are not filled by the liquid film of the refrigerant, but in the case of the dense mesh layer 140a, all of the empty spaces of the lattice are filled by the liquid film of the refrigerant.

The plate heat transfer apparatus 100 starts a heat transfer operation from the heat source 110 to the heat dissipation unit 120 when the temperature of the heat source 110 is higher than the vaporization temperature of the refrigerant. Specifically, since the heat generated from the heat source 110 is transferred to the adjacent dense mesh layer 140a, vaporization of the refrigerant is caused in the dense mesh layer 140a. Of course, the vaporization of the coolant is also caused in the coarse mesh layer 140b, but the amount is smaller than the amount of vaporization of the coolant caused in the dense mesh layer 140a. The vaporized refrigerant is diffused in all directions through the adjacent coarse mesh layer 140b, and a region having a temperature lower than the vaporization temperature of the refrigerant among the inner surfaces of the plate-shaped case 130, substantially the heat dissipation unit 120. It is condensed in the dense mesh layer 140a near immediately below.

In the process of evaporating and condensing the refrigerant, the refrigerant takes heat from the heat source 110 and transfers the heat to the heat dissipation unit 120. The heat transferred to the heat dissipation unit 120 is discharged to the outside by the forced convection method by the fan 150, and thus the temperature of the heat source 110 is maintained at an appropriate line. In an ideal case, the heat transfer mechanism by evaporation and condensation of the refrigerant continues until the temperature of the heat source 110 and the temperature of the heat dissipating part 120 become substantially the same.

When vaporization and condensation of the refrigerant is induced in the plate heat transfer device 100, the equilibrium state of interfacial energy is disturbed in the mesh layer assembly 140. Here, the interface energy refers to the contact interface between the surfaces of the mesh layers 140a and 140b and the liquid refrigerant. That is, at the point where the refrigerant evaporates, the interfacial energy increases before heat transfer occurs (equilibrium), and at the point where the refrigerant condenses occurs, the interfacial energy decreases before the heat transfer occurs (equilibrium). As a result, there is a tendency to solve the disturbance of the interfacial energy in the mesh layer assembly 140.

Accordingly, there is a tendency for the refrigerant to flow from the periphery to the point where the refrigerant is vaporized, and a tendency for the refrigerant to be discharged to the periphery at the point where the refrigerant is condensed, whereby the flow of the condensed refrigerant in the mesh layer assembly 140 Occurs. On the average, the flow of the condensation refrigerant occurs from the heat dissipation part 120 to the outer periphery of the mesh layer assembly 140 and again from the outer periphery toward the heat source 110.

In the plate heat transfer apparatus 100, the sparse mesh layer 100b mainly provides a diffusion path of the vaporized refrigerant as described above. Specifically, in the sparse mesh layer 140b, as shown in FIG. 4, there is a wedge-shaped space generated by crossing the horizontal wire 160a and the vertical wire 160b up and down. It will function as a steam diffusion passage 170 that can.

The geometric area A of the vapor diffusion flow path 170 is calculated as in Equation 2 below.

Referring to Equation 2, the geometric area of the vapor diffusion flow path 170 increases as the mesh number N decreases and the diameter d of the mesh wire increases.

In the lattice of the sparse mesh layer 140b, there are four vapor diffusion passages 170 which are shared with the neighboring lattice, so that the diffusion of the gaseous refrigerant is based on the center of the mesh lattice (see 'O' in FIG. 3). It is made in all directions (see arrow '↔' in Fig. 3).

Meanwhile, when the plate heat transfer device 100 according to the present invention is actually operated, the coarse mesh layer 140b has a liquid film 180 formed by a liquid refrigerant in a wedge-shaped gap of the vapor diffusion flow path 170 as shown in FIG. 5. Will be formed. As shown in FIG. 6, the liquid film 180 is formed at all intersection points of the coarse mesh wire 160b, and the liquid films formed at adjacent intersection points adjacent to each other are connected to each other (see 190).

The liquid film 180 can be connected by appropriately controlling the width N of the mesh lattice and / or the diameter d of the mesh wire among the parameters of the coarse mesh layer 140b, and the horizontal flow of the refrigerant by capillary force is controlled. It acts to induce. Therefore, in the coarse mesh layer 140b, the diffusion of the gaseous refrigerant is mainly induced through the vapor diffusion passage 170, but a horizontal flow of the liquid refrigerant is caused by the capillary force caused by the connected liquid film 180. The horizontal flow flow rate induced at this time is relatively small in comparison with that induced at the dense mesh layer 140a.

The liquid films 180 are connected not only in the coarse mesh layer 140b as shown in FIG. 5 but also in the liquid film existing in the dense mesh layer 140a which is directly and directly below (see 200). . The liquid film connection between the different mesh layers is made through a contact interface formed between the coarse mesh layer 140b and the dense mesh layer 140a. In the operation of the plate heat transfer apparatus 100, the interconnection of the liquid film present in the coarse mesh layer 140b and the liquid film present in the dense mesh layer 140a provides smooth vertical flow of the liquid refrigerant between the different layer layers. Make it possible.

As described above, vaporization of the liquid refrigerant is continuously induced in the heat transfer process in an area near the top of the heat source 110 among the areas of the dense mesh layer 140a, so that the liquid refrigerant must be continuously supplied accordingly. However, in order to continuously supply the liquid refrigerant to the dense mesh layer 140a due to the geometry of the mesh layer assembly 140, the coarse mesh layer 140b disposed between the dense mesh layers 140a may be formed of the condensed refrigerant. It must serve as a bridge to vertical flow. This vertical movement of the refrigerant is made possible by the vertical connection of the liquid film 180 present in the dense mesh layer 140a and the coarse mesh layer 140b (see 200 in FIG. 5). That is, the vertical connection of the liquid film 180 maintains the capillary force in the vertical direction, thereby allowing the condensed refrigerant to flow smoothly in the vertical direction.

As described above, the coarse mesh layer 140b provides a vapor diffusion flow path 170 so that the refrigerant vaporized in the dense mesh layer 140a can quickly diffuse into a region having a lower temperature than the heat source 110. At the same time, a crosslinking role for the vertical flow of the refrigerant is performed so that the refrigerant condensed into the adjacent dense mesh layer 140a can be smoothly supplied. Accordingly, the heat transfer efficiency of the apparatus 100 is maximized by smoothly supplying the condensed refrigerant near the heat source 110 during the operation of the plate heat transfer apparatus 100. In addition, the coarse mesh layer 140b also serves to support the plate-shaped case 130, thereby increasing the mechanical strength of the plate-shaped heat transfer device 100, thereby making it possible to make the device 100 ultra-thin.

In the sparse mesh layer 140b, the diffusion of the gaseous refrigerant and the flow of the liquid refrigerant should occur at the same time. Therefore, it is preferable to appropriately select the mesh number and the diameter of the mesh wire. At this time, when the number of meshes of the coarse mesh layer 140b is very large and the diameter of the mesh wire is very small, the area of the vapor diffusion flow path 170 is reduced to increase the flow resistance of the gaseous refrigerant and the vapor diffusion flow path by the surface tension ( 170 It should be taken into account that the self-filled liquid phase does not cause diffusion of the gaseous refrigerant.

In view of this, when the screen mesh according to ASTM specification E-11-95 is used as the coarse mesh layer 140b, the number of meshes is 10 or more and 20 or less, and the screen diameter of the mesh wire is 0.2 mm or more and 0.4 mm or less. It is desirable to select a mesh. Selecting the screen mesh in such a condition, the diffusion of the gaseous refrigerant and the horizontal and vertical flow of the liquid refrigerant in the coarse mesh layer 140b is caused at the same time.

The dense mesh layer 140a near the heat source 110 causes vaporization of the liquid refrigerant during the operation of the plate heat transfer device 100, and the dense mesh layer 140a near the heat radiating unit 120. In this case, condensation of the gaseous refrigerant is caused. In this process, the continuous supply of the liquid refrigerant to the upper portion of the heat source 110 from the lower portion of the heat dissipating portion 120 on the average due to the capillary force caused in the horizontal or vertical direction should be made smoothly.

To this end, it is preferable that an empty space of the lattice is filled by the liquid film while there is an interconnected liquid film 180 that provides capillary force at the wire crossing point of the dense mesh layer 140a. This is achieved by appropriately selecting the mesh number and wire diameter of the dense mesh layer 140a.

When using a screen mesh according to ASTM specification E-11-95 as the dense mesh layer 140a, it is preferable to select a screen mesh having a mesh number of 80 or more and 400 or less and a mesh wire having a diameter of 0.03 mm or more and 0.13 mm or less.

In the first embodiment of the present invention described above, the dense mesh layer 140a may be replaced with a wick structure, and in some cases, the dense mesh layer 140a under the heat dissipation part 120 may be omitted. In this case, since the liquid film is formed in the coarse mesh layer 140b and the refrigerant is condensed in this portion, as shown in FIGS. 5 and 6, the coarse mesh layer itself serves as a condenser. The wick structure may be produced by sintering copper, stainless, aluminum, or nickel powder, or may be one obtained by etching a polymer, silicon, silica, copper plate, stainless steel, nickel, or aluminum plate. Furthermore, the wick structure may be manufactured by the micromachining method disclosed in US Pat. No. 6,056,044 to Benson et al.

In the present invention, the plate-shaped case 130 in which the mesh layer assembly 140 is accommodated is in a state in which the inside thereof is depressurized by a vacuum, and the material absorbs heat from the heat source 110 and returns to the heat radiating part 120 again. It is made of a metal with high thermal conductivity, a conductive polymer, a metal coated with a conductive polymer, or a thermally conductive plastic so as to easily release heat.

Preferably, the metal is any one of copper, aluminum, stainless steel or molybdenum or alloys thereof. In particular, when the plate-shaped case 130 is made of an electrolytic copper foil having a small unevenness of about 10㎛ on one side, it is preferable to face the surface with the unevenness toward the inner surface of the plate-shaped case 130. In this case, the flow of the refrigerant by capillary forces is induced on the inner surface of the plate case 130, so that the refrigerant is returned to the heat source 110 in the vicinity of the heat source 110, and thus the heat transfer performance of the plate heat transfer device 100. This will increase further. The plate-shaped case 130 preferably has a thickness of 0.01 mm or more and 3.0 mm or less in view of thermal conductivity and mechanical strength.

7 shows the configuration of a plate heat transfer apparatus according to a second embodiment of the present invention. In the second embodiment of the present invention, the stacking method of the mesh layer assembly differs from the first embodiment described above, and the rest of the configuration is substantially the same.

Referring to FIG. 7, in the plate heat transfer apparatus 100 ′ according to the second embodiment of the present invention, a dense mesh layer 140a and a coarse mesh layer 140b alternately stacked form a mesh layer assembly 140. do. Here, the dense mesh layer 140a and the coarse mesh layer 140b are the same as those of the first embodiment and contact each other in the stacking direction.

The configuration of the mesh layer assembly 140 as described above ensures a relatively better heat transfer performance than the plate heat transfer apparatus 100 shown in FIG. Expression of such excellent heat transfer performance causes simultaneous evaporation of the refrigerant in the plurality of dense mesh layers 140a and then causes rapid diffusion of simultaneous multiple refrigerant vapors through the plurality of adjacent coarse mesh layers 140b. In addition, the coarse mesh layer 140b simultaneously functions as a vapor diffusion passage and crosslinks the vertical flow of the condensed liquid refrigerant, thereby reducing the return time of the refrigerant and supplying the refrigerant per unit time to the heat source 110. This is possible because it brings an increase.

In the mesh layer assembly 140, the units of the mesh layers stacked alternately are not limited to only one layer. However, when the dense mesh layer 140a is composed of three or more layers, the evaporated refrigerant may be trapped in the laminated structure of the dense mesh layer 140a, thereby preventing the flow of the liquid refrigerant. Therefore, the dense mesh layer 140a is preferably laminated in two layers or less.

During the operation of the plate heat transfer apparatus 100 ′, heat generated in the heat source 110 is transferred to not only the adjacent dense mesh layer 140a but also to the non-adjacent dense mesh layer 140a, so that each dense mesh layer At 140a, vaporization of the coolant is caused simultaneously. Accordingly, the heat transfer performance per unit time is improved. The vaporization of the refrigerant is also caused in the coarse mesh layer 140b, but the amount is smaller than the amount of vaporization of the refrigerant caused in the dense mesh layer 140a.

The vaporized refrigerant diffuses in all directions through the plurality of coarse mesh layers 140b adjacent to the dense mesh layer 140a, and is a region having a temperature lower than the vaporization temperature of the refrigerant in the inner surface of the plate case 130, substantially. Is condensed in the immediate vicinity of the heat dissipation unit 120. The condensed refrigerant is discharged to the outside through the heat dissipation unit 120.

The condensed refrigerant flows near the heat source 110 on average due to capillary forces caused in the mesh layer assembly 400. At this time, the flow of the condensation refrigerant occurs even in its own layer of the dense mesh layer 140a and the coarse mesh layer 140b, but mainly between the dense mesh layer 140a and the coarse mesh layer 140b constituting different layers. Is triggered. Refrigerant flow between mesh layers forming different layers is achieved through contact interfaces between the mesh layers. At this time, the mechanism associated with the vertical flow of the refrigerant is substantially the same as in the above-described embodiment.

In particular, the sparse mesh layer 140b provides a vapor diffusion flow path so that the vaporized refrigerant in the dense mesh layer 140a can quickly diffuse into a region having a lower temperature than the heat source 110, A crosslinking role is performed for vertical flow of the refrigerant so that the refrigerant condensed into the adjacent dense mesh layer 140a may be smoothly supplied. Accordingly, the heat transfer efficiency of the apparatus 100 ′ is maximized by smoothly supplying the condensed refrigerant near the heat source 110 during the operation of the plate heat transfer apparatus 100 ′.

In the second embodiment of the present invention, the method of constructing the mesh layer assembly 140 using the dense mesh layer 140a and the coarse mesh layer 140b may variously modify the example shown in FIG. 7. 8 to 10 show various such modifications.

Referring to FIGS. 7 and 8 to 10, for example, the dense mesh layer 140a on the uppermost layer may be omitted in configuring the mesh layer assembly 140 (see FIG. 8). As another example, the top and bottom may be composed of a plurality of dense mesh layers 140a (see FIG. 10). As another example, the topmost dense mesh layer 140a may be omitted and the bottom may be composed of a plurality of dense mesh layers 140a (see FIG. 9).

On the other hand, in the second embodiment and its modifications, the dense mesh layer constituting the mesh layer assembly may be replaced with various wick structures known in the art as in the first embodiment.

The plate-shaped heat transfer apparatus according to the present invention, as shown in Figures 11 to 13, can be configured in a variety of shapes, such as square, rectangular, T-shaped. The plate-shaped case of the plate heat transfer device may be configured by a separate combination of the upper plate case 130a and the lower plate case 130b, as shown in FIGS. 14 and 15, or may be configured as only one case as shown in FIG. It may be.

In the present invention, the final sealing of the plate-shaped case is carried out after the refrigerant is charged in a state where the inside is decompressed to a vacuum level. The sealing is made of laser welding, plasma welding, TIG welding, ultrasonic welding, brazing bonding, soldering bonding, thermocompression lamination, or the like.

As the refrigerant injected into the plate-shaped case, water, methanol, ethanol, acetone, ammonia, CFC-based refrigerant, HCFC-based refrigerant, HFC-based refrigerant, or a mixed refrigerant thereof may be employed.

In the plate heat transfer apparatus according to the present invention described above, the sparse mesh layer not only serves as a vapor flow path, but also performs a role of crosslinking for vertical flow as well as horizontal flow of the liquid refrigerant. The dual action of such coarse mesh layer is an essential matter of the plate-shaped heat transfer apparatus according to the present invention, and is achieved by appropriately selecting the number of meshes and the diameter of the mesh wire that the coarse mesh layer has.

Hereinafter, by actually measuring the performance dependence of the heat transfer device according to the mesh number and the wire diameter of the coarse mesh layer employed in the present invention, the conditions for the coarse mesh layer to perform a dual action was derived through Experiment 1.

<Experiment 1>

As the coarse mesh layer, a screen mesh made of copper according to each case of Table 1 was selected. As the dense mesh layer, a screen mesh having a material of copper, a mesh number of 100, and a mesh wire diameter of 0.11 mm was selected. Then, 11 mesh layer aggregates were constructed in a structure as shown in FIG.

TABLE 1

case Wire diameter [mm] Mesh # / inch R [℃ / W] One 0.20 15 0.70 2 0.20 24 0.74 3 0.20 50 ∞ 4 0.35 10 0.67 5 0.35 12 0.63 6 0.35 14 0.61 7 0.35 16 0.65 8 0.35 18 0.67 9 0.35 30 ∞ 10 0.48 10 0.78 11 0.71 8 ∞

Subsequently, each of the plurality of mesh layer assemblies was mounted in a plate-shaped case separated up and down, and sealed using a modified acrylic two-component bond (trade name: HARDLOC) manufactured by DENKA, Japan. At this time, an oxygen-free copper plate having a thickness of 0.2 mm was used as the plate-shaped case, and the width and length of the plate-shaped case were 80 mm and 70 mm, respectively.

After sealing the plate-shaped case as described above, using a rotary vacuum pump and a diffusion vacuum pump to depressurize the inside of the plate-shaped case to 1.0 × 10 ^-7 torr, and then filled with 0.23 cc of refrigerant distilled water and finally sealing A total of 11 plate heat transfer device samples were prepared.

After each plate heat transfer device was fabricated, the heat transfer performance for each device was measured as follows and shown in the heat resistance column of Table 1 above.

First, a copper block heat source having a width of 30 mm and a length of 30 mm was attached to the top of the heat transfer device. Inside the copper block, two cartridge-type heaters generating 50W of heat at 240V were installed. A thermocouple was attached to the surface of the copper block to measure the temperature of the copper surface. A pin heat sink made of copper was attached to the bottom of the heat transfer device to function as a heat dissipation unit.

Through such a configuration, the return of the refrigerant is reversed to gravity, and the return force of the refrigerant can be compared with each other for each heat transfer device. The horizontal and vertical sizes of the fin heat sink are the same as those of the heat transfer device.

In a specific experiment, a total of 90 W of heat was supplied through the cartridge heater. Then, the surface temperature of the copper block was measured at an outdoor temperature of 22 ° C. Then, the thermal resistance (R [° C./W]) value was calculated based on the difference between the surface temperature of the copper block and the ambient temperature.

Thermal resistance values for each heat transfer device are shown in Table 1 above. As a result, the wire resistance was lowest when the diameter of wire was 0.35mm and the number of mesh was 14. When the diameter of the wire was 0.35 mm, the thermal resistance increased as the number of meshes decreased or increased than 14.

When the wire diameter is 0.35 mm, the area of the vapor flow path increases geometrically when the number of meshes is less than 14. However, the increase in the thermal resistance is due to the increase in the area occupied by the wedge-shaped liquid film formed in the cross-section of the coarse mesh layer. Because. From this, it can be seen that the material of the coarse mesh layer affects the performance of the heat transfer device. Therefore, when constructing a heat transfer apparatus, it is preferable that the material of a coarse mesh layer is metal.

In addition, when the wire diameter is 0.35mm, the increase in the heat resistance when the number of meshes is greater than 14 means that the increase in the heat resistance due to the increase in flow resistance due to the decrease in the steam flow path is higher than the heat transfer amount due to the heat conduction of the coarse mesh layer Because it is a cut.

In particular, when the wire diameter is 0.2mm and the number of meshes is 50, the temperature of the copper surface is continuously raised to obtain a result. This is because the steam flow path was reduced so much that steam could not diffuse to the entire portion of the plate heat transfer device and condensed steam.

Through the results of the experiment, the applicant was able to infer the performance of the plate heat transfer apparatus according to the change of the diameter and the number of meshes of the coarse mesh layer. The diameter of the coarse mesh wire is 0.2 mm or more and 0.4 mm or less and the number of meshes If it is 10 or more and 20 or less, it was confirmed that the plate heat transfer device can exert an effective function as an actual cooling device.

Next, the Applicant compares the heat transfer performance of the plate-shaped heat transfer apparatus according to the first and second embodiments of the present invention with each other, thereby performing correlation 2 regarding the heat transfer performance of the apparatus by the mesh layer aggregate structure. It was confirmed through.

<Experiment 2>

Applicant has produced a plate heat transfer device (hereinafter referred to as sample 1) so that the width, length and height are 150 mm, 50 mm and 2.25 mm, respectively, in order to examine the effect of the plate heat transfer device according to the present invention. The plate case was configured by separately combining the upper plate case and the lower plate case, the material was used a rolled copper foil having a thickness of 0.1mm.

The mesh layer assembly to be mounted inside the plate-shaped case was laminated as shown in FIG. 7 using a copper screen mesh having a copper content of 99% or more. As the coarse mesh layer, a screen mesh having a material of copper, a wire diameter of 0.35 mm, a layer thickness of 0.74 mm, and a mesh number of 14 was used. As the dense mesh layer, a material was copper, a screen mesh having a wire diameter of 0.11 mm, a layer thickness of 0.24 mm, and a mesh number of 100 was used.

In order to prepare Sample 1 to be used in this experiment, a mesh layer assembly was first mounted between the upper case and the lower case, and a refrigerant inlet was used using a modified acrylic bicomponent bond (trade name: HARDLOC) manufactured by DENKA, Japan. Leave it sealed.

Then, after the refrigerant was injected into the plate case by using a rotary vacuum pump and a diffusion vacuum pump to reduce the pressure to 1.0 × 10 ^-7 torr, the refrigerant was filled with 3.91cc and finally sealed.

Meanwhile, in order to compare the performance with the plate heat transfer device manufactured as described above, a plate heat transfer device (hereinafter, referred to as Sample 2) was manufactured with a simple stacked structure of a dense mesh layer and a coarse mesh layer. The dense mesh layer and the coarse mesh layer used for the preparation of Sample 2 are the same as those used for the preparation of Sample 1. Sample 2 was prepared in the same manner as Sample 1, except that the thickness thereof was 1.35 mm and the amount of refrigerant charged was 3.12 cc.

After preparing the samples 1 and 2 as described above, a fin heat sink having a width of 80 mm and a width of 61 mm and a height of 40 mm, respectively, was installed on the upper surfaces of the samples 1 and 2, and a cooling fan was mounted thereon. And the lower surface of the sample 1 and the sample 2 was attached to a copper block heat source of 31mm in width and length respectively. Then, when the calorific value of the heat source was 70W under the same ambient conditions and constant fan speed, the temperature of the heat source surface was measured.

As a result of the experiment, when the ambient temperature is 25 ℃, in the heat generation amount of the heat source in the sample 2 was 70W, the temperature of the heat source was 69 ℃, in the case of sample 1 the temperature of the heat source was 58 ℃. From this, it can be seen that the heat transfer performance of the plate-shaped heat transfer device is improved as a result of alternately laminating the dense mesh layer and the coarse mesh layer.

Through the above experiments, when the coarse mesh layer and the dense mesh layer are alternately repeatedly stacked as in the plate heat transfer apparatus according to the second embodiment of the present invention, diffusion of vaporized refrigerant occurs simultaneously in a plurality of coarse mesh layers. It can be seen that by making the smooth return of the liquid refrigerant condensed through the coarse mesh layer, the heat transfer performance is improved.

In the above described with reference to the accompanying drawings, preferred embodiments of the present invention in detail. However, embodiments of the present invention may be variously modified or applied by those skilled in the art, the scope of the technical idea according to the present invention should be determined by the claims below. will be.

According to an aspect of the present invention, by stacking a dense mesh layer (or wick structure) and a coarse mesh layer inside the plate-shaped case to cause the refrigerant flow in the vertical direction by capillary force to quickly and smoothly near the heat source Can be supplied as

According to another aspect of the present invention, it is possible to simultaneously induce multiple vaporization and diffusion of the refrigerant in the mesh layer assembly, in particular to ensure a large surface area for vaporization and condensation of the refrigerant in the alternately stacked screen mesh The heat transfer performance of the plate heat transfer device is maximized.

According to another aspect of the present invention, since the plate-shaped case is supported by the mesh layer assembly, it is possible to prevent the device from being deformed even when a mechanical shock is applied.

Claims (31)

A thermally conductive plate-shaped case installed between the heat source and the heat dissipating unit and containing a refrigerant condensed while absorbing heat from the heat source and dissipating heat from the heat dissipating unit; And And a mesh layer assembly installed inside the plate-shaped case and having a structure in which a dense mesh layer and a coarse mesh layer face each other. The coarse mesh layer is a screen mesh, the wire diameter of 0.20mm or more and 0.40mm or less, the plate-shaped heat transfer device, characterized in that 10 to 20 or less. The method of claim 1, And another dense mesh layer facing the dense mesh layer while facing the dense mesh layer with the coarse mesh layer interposed therebetween. The method according to claim 1 or 2, The dense mesh layer is a plate-type heat transfer device, characterized in that the woven mesh wire of 0.03mm or more and 0.13mm or less, or the screen mesh of 80 to 400 mesh number. The method according to claim 1 or 2, The sparse mesh layer is a plate heat transfer device, characterized in that made of a metal material. A thermally conductive plate-shaped case installed between the heat source and the heat dissipating unit and containing a refrigerant condensed while absorbing heat from the heat source and dissipating heat from the heat dissipating unit; And And a mesh layer assembly installed inside the plate-shaped case and having a structure in which a dense mesh layer and a coarse mesh layer face each other. The sparse mesh layer is a screen mesh of metal material having a wire diameter of 0.20 mm or more and 0.40 mm or less and a mesh number of 10 or more and 20 or less, and a path through which a liquid refrigerant flows in a horizontal and vertical direction by capillary force and a gaseous refrigerant. A plate heat transfer device characterized by providing a diffusion path. A thermally conductive plate-shaped case installed between the heat source and the heat dissipating unit and containing a refrigerant condensed while absorbing heat from the heat source and dissipating heat from the heat dissipating unit; And And a mesh layer assembly installed inside the plate-shaped case and having a stacked structure facing the wick structure and the coarse mesh layer. The coarse mesh layer is a screen mesh, the wire diameter of 0.20mm or more and 0.40mm or less, the plate-shaped heat transfer device, characterized in that 10 to 20 or less. The method of claim 6, And another wick structure facing the coarse mesh layer while facing the wick structure with the coarse mesh layer interposed therebetween. The method according to claim 6 or 7, The wick structure is a plate heat transfer device, characterized in that produced by sintering copper, stainless, aluminum or nickel powder. The method according to claim 6 or 7, The wick structure is a plate heat transfer device, characterized in that produced by etching the polymer, silicon, silica (SiO ₂ ), copper plate, stainless steel, nickel or aluminum plate. The method according to claim 6 or 7, The coarse mesh layer is a plate heat transfer device, characterized in that made of a metal material. A thermally conductive plate-shaped case installed between the heat source and the heat dissipating unit and containing a refrigerant condensed while absorbing heat from the heat source and dissipating heat from the heat dissipating unit; And And a mesh layer assembly installed inside the plate-shaped case and having a stacked structure facing the wick structure and the coarse mesh layer. The sparse mesh layer is a screen mesh of metal material having a wire diameter of 0.20 mm or more and 0.40 mm or less and a mesh number of 10 or more and 20 or less, and a path through which a liquid refrigerant flows in a horizontal and vertical direction by capillary force and a gaseous refrigerant. A plate heat transfer device characterized by providing a diffusion path. A thermally conductive plate-shaped case installed between the heat source and the heat dissipating unit and containing a refrigerant condensed while absorbing heat from the heat source and dissipating heat from the heat dissipating unit; And And a mesh layer assembly installed inside the plate case and having a structure in which a dense mesh layer and a coarse mesh layer are alternately stacked repeatedly. The method of claim 12, The sparse mesh layer is a plate-shaped heat transfer device, characterized in that the screen mesh is woven from mesh wire having a diameter of 0.2 or more and 0.4 mm or less and the number of meshes is 10 or more and 20 or less. The method of claim 12, The dense mesh layer is a plate-shaped heat transfer device, characterized in that the woven mesh wire of 0.03 or more and 0.13mm or less in diameter, or the screen mesh of 80 to 400 mesh number. The method of claim 12, And the dense mesh layer and the coarse mesh layer are alternately stacked to be in contact with each other. The method of claim 12, The structure of the mesh layer assembly is going from bottom to top, A plate heat transfer apparatus having a structure in which a dense mesh layer, a coarse mesh layer, a dense mesh layer, a coarse mesh layer, and a dense mesh layer are stacked in this order. The method of claim 12, The structure of the mesh layer assembly is going from bottom to top, A plate heat transfer apparatus having a structure in which a dense mesh layer, a coarse mesh layer, a dense mesh layer, and a coarse mesh layer are stacked in this order. The method of claim 12, The structure of the mesh layer assembly is going from bottom to top, A plate heat transfer device having a structure in which two or more layers are stacked in order of a dense mesh layer, a coarse mesh layer, a dense mesh layer, and a coarse mesh layer. The method of claim 12, The structure of the mesh layer assembly is going from bottom to top, A plate heat transfer apparatus having a structure in which two or more dense mesh layers, a coarse mesh layer, a dense mesh layer, a coarse mesh layer, and two or more dense mesh layers are stacked in this order. The method of claim 12, The dense mesh layer is a plate heat transfer device, characterized in that to provide a flow path of the liquid refrigerant. The method of claim 12, The sparse mesh layer is a plate-type heat transfer device, characterized in that to provide a flow path of the liquid refrigerant and the diffusion path of the gaseous refrigerant at the same time. The method according to any one of claims 1, 5, 6, 11 and 12, The plate case is made of an electrolytic copper foil, The plate-shaped heat transfer apparatus characterized by the uneven surface of the said electrolytic copper foil comprise the inner surface of the said case. The method of claim 12, And said coarse mesh layer and said dense mesh layer are woven from mesh wire made of metal, polymer, plastic or fiberglass. The method according to any one of claims 1, 5, 6, 11 and 12, The plate-shaped case is a plate, heat transfer device, characterized in that made of a metal, a conductive polymer, a metal or conductive plastic coated with a conductive polymer. The method of claim 24, And said metal is copper, aluminum, stainless steel, molybdenum or an alloy thereof. The method according to any one of claims 1, 5, 6, 11 and 12, And said plate case is sealed by laser welding, plasma welding, TIG welding, ultrasonic welding, brazing bonding, soldering bonding or thermocompression lamination. The method according to any one of claims 1, 5, 6, 11 and 12, And the refrigerant is water, methanol, ethanol, acetone, ammonia, CFC refrigerant, HCFC refrigerant, HFC refrigerant or a mixed refrigerant thereof. A thermally conductive plate-shaped case installed between the heat source and the heat dissipating unit and containing a refrigerant condensed while absorbing heat from the heat source and dissipating heat from the heat dissipating unit; And Installed inside the plate-shaped case, the wick structure providing a flow path of the liquid refrigerant by capillary force and the coarse mesh layer providing the flow path of the liquid refrigerant by the capillary force and the diffusion path of the gaseous refrigerant at the same time are alternately in contact with each other. And a mesh layer assembly having a repeatedly stacked structure as a plate-shaped heat transfer apparatus. The method of claim 28, The wick structure is a plate heat transfer device, characterized in that produced by sintering copper, stainless, aluminum or nickel powder. The method of claim 28, The wick structure is a plate heat transfer device, characterized in that produced by etching the polymer, silicon, silica (SiO ₂ ), copper plate, stainless steel, nickel or aluminum plate. The method of claim 28, The wick structure or the coarse mesh layer is a plate-shaped heat transfer device, characterized in that composed of two or more layers.

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