KR100982957B1 - Method for manufacturing Evaporator for loop heat pipe system - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an evaporator for a loop heat pipe (LHP) system, wherein a groove is formed to groove a groove-shaped groove of a fan string concave and elongated on one side of a metal plate. Processing step; A groove filling step of filling a groove of the heating plate with a groove filling material including a sublimable solid material; A jig providing step including a jig positioned to be spaced apart from one side of the heating plate on which the groove is formed; A metal powder filling step of filling a metal powder in a space formed between one side of the heating plate and the jig; And a sintering step of forming the porous sintering wick by heating the metal powder so as to be sintered.

Description

Method for manufacturing evaporator for loop heat pipe system {Method for manufacturing Evaporator for loop heat pipe system}

The present invention relates to a method of manufacturing an evaporator which forms a loop heat pipe system together with a condenser, a gas conveying pipe and a liquid conveying pipe, and in particular, a loop heat pipe system capable of improving the contact state between a sintering wick and a heating plate by a simple manufacturing process. The present invention relates to a method for preparing a vaporizer for evaporation.

Electronic components such as CPUs and semiconductor chips used in various electronic devices such as computers generate a lot of heat during operation. Since such electronic products are usually designed to function properly at room temperature, if the heat generated during operation is not effectively cooled, their performance may be remarkably degraded and, in some cases, even damage to the product.

Various technologies such as heat conduction method using heat sink, natural convection and radiation method of air, forced convection method using fan, liquid circulation method or submersible cooling method have been developed as a cooling method for cooling the heat of electronic components. It is used.

However, as the electronic products become thinner and thinner, the intervals between installation of the electronic components that generate heat during operation continue to narrow, and thus the heat generated when the electronic products are used is not properly cooled. In addition, since the heat load of the electronic components continues to increase due to the high integration and high performance of the electronic components, the above-described conventional cooling method may not effectively cool the electronic components.

As a new technology to solve this problem, the introduction of a phase change heat transport system capable of cooling an electronic component having a high heat load density per unit has recently been expanded. Examples of such phase change heat transfer systems include thermal siphon (thermosyphon) and cylindrical heat pipes.

Thermal siphon is a method of cooling by natural circulation in the gravitational field due to the change of the liquid-vapor phase of the working fluid and the difference in specific gravity. A typical cylindrical heat pipe is a sintering wick installed on the inner wall of a pipe. Circulating the working fluid using the capillary pumping force of the wick.

However, thermosiphons require condensation to be higher than the evaporator and cylindrical bottompipes are less dependent on the gravitational field than thermal siphons, but the heat transfer capacity is significantly reduced if the condensation is located below the evaporator in the gravitational field. Since the two systems have a limited positional relationship between the components, there is a disadvantage in that they act as a constraint on the slimming of electronic products employing the cooling system.

In addition, in the heat siphon and the cylindrical heat pipe, steam and liquid are mixed in the middle of the tube because steam and liquid flow in opposite directions in the straight tube. There is also a big problem that this mixing makes a substantial amount of heat actually delivered rather than theoretically transferable.

The Loop Heat Pipe (LHP) system has been proposed as an ideal heat transfer system that can solve these problems, namely, space and location constraints, and the problem of mixing vapor and liquid.

Loop heat pipe system is a kind of CLP (Capillary Pumped Loop Heat Pipe) technology developed by NASA in USA to cool large amount of heat generated from satellite communication equipment and electronic equipment.

As a related art related to a miniaturized loop heat pipe system, Korean Patent No. 671041 (name of the invention: loop hip pipe) is provided. 1 is a conceptual diagram of a loop heat pipe system 110 disclosed in the prior art, in which a conventional loop heat pipe system 110 includes a condenser 112, an evaporator 114, and a vapor line 116 and a liquid connecting them. Lines 118 are each connected to form a loop. In the case of the roof heat pipe system 110, unlike the conventional cylindrical heat pipe, the sinter wick 120 is installed only in the evaporator 114. Meanwhile, in the present specification, the loop heat pipe is also referred to as a loop heat pipe system, and both names are used interchangeably in the same sense, and the evaporator and the condenser have the same meaning as the evaporator and the condenser, respectively.

The principle of the operation of the loop heat pipe system 110 of this configuration is as follows.

First, when the lower member of the evaporator into which the sintered wick 120 is inserted is heated by a heat source as the heating plate 122, the working fluid that has permeated the sintered wick 120 by the heat transferred from the heating plate 122. Is heated to saturation temperature and changes phase into gas. At this time, the generated gas is moved to the condenser 112 along the steam line 116 connected to one side of the evaporator 114. Subsequently, when the gas liquefies by releasing heat to the outside while passing through the condenser 112, the liquefied working fluid is moved back to the evaporator 114 along the liquid line 118 on one side of the condenser 112, The process is repeated and the heat source is cooled.

The process of vaporizing the working fluid that permeated the sintered wick 120 will be described in more detail. Referring to FIG. 3, which is a schematic cross-sectional view according to III-III of FIG. 2, and FIG. 4, which is shown 180 degrees of the sintering wick shown in FIG. 2 for convenience of description, of the sintered wick 120 facing the heating plate 122. The surface 126 is provided with a surface (contact surface) 126b in contact with the heating plate 122 and a microchannel 126a formed to serve as a passage for generated steam. Therefore, the sintered wick 120 receives heat from the surface 126b which is in contact with the heating plate 122, and the working fluid that has penetrated the sintered wick 120 is vaporized by the heat. The generated gas is moved to the condenser 112 along the steam line 116 connected to one side of the evaporator 114 through the fine channel 126a formed on the surface 126 facing the sintered wick 120.

At this time, the performance of the evaporator, which is an object of interest of the present invention and serves to take heat away from a heat source such as an electronic component, greatly depends on how well the heat generated from the heat source and transferred to the heating plate is transferred to the sintering wick. do. One factor that directly affects heat transfer between them is contact conductance.

Contact conductance is related to the contact thermal resistance that occurs when a metal is in surface contact with another metal and heat transfer occurs between them. Contact conductance is proportional to the contact area of the two metals in contact and is affected by the contact bonding state. That is, the larger the contact area and the better the contact state, the larger the value of the contact conductance is, and the larger the value of the contact conductance is, the better the heat transfer occurs.

By the way, in the conventional method for manufacturing the evaporator employed in the loop heat pipe system, a sintered wick having a channel, which is a vapor passage, is separately manufactured and then coupled to a heating plate, which makes the manufacturing process complicated and the combined surface state. Has disadvantages such as not good. Before explaining the disadvantages, first, the conventional method of bonding the sintered wick to the heating plate includes a simple compression method and a metal bonding method, which will be described first.

The simple pressing method is a method of contact bonding the sintered wick and the heating plate by taking a method of applying a constant load by processing / unprocessing the contact portion of the metal sintered wick manufactured in advance. In the metal bonding method, the metal powder is sintered in advance to form a sintered wick, and a channel, which is a vapor passage, is formed therein. This is how the metal bond is made.

Meanwhile, in the case of metal bonding method, there is a method used in a general cylindrical sintered wick heat pipe. In this method, sintering of metal powder is carried out by assisting the metal powder in contact with the heating interface by using a jig. It is a method of bonding to the inner wall of the metal pipe. In the case of the cylindrical heat pipe, since the steam is not generated at the interface between the metal and the sintered wick, and is generated at the surface of the sintered wick, a separate steam passage is not required. Can be. However, in order to manufacture the evaporator used in the conventional loop heat pipe system, since the steam is formed in the form of bonding the sintered wick formed with the steam passage to the heating plate, the steam is generated at the interface between the sintered wick and the heating plate, As in the case of pipes, the method of sintering metal powder directly after mounting it on a heating plate cannot be used, and a steam passage must be formed on one side of the sintered wick, and then one side is mounted on the heating plate of the metal and then resintered. There was no choice but to use a metal bonding method.

As a result, in order to manufacture the evaporator employed in the conventional loop heat pipe system, after sintering the metal powder and forming a channel therein, the sintered wick in which such a channel is formed must be bonded to the heating plate by simple pressing or metal bonding. Therefore, there was a disadvantage that the manufacturing process is complicated and takes a lot of manufacturing costs, and in particular, the coupling between the heating plate and the sintered wick is not good, the value of the contact conductance is lowered, so that the heat transfer is not effective enough. In addition, in the case of the metal bonding method of re-sintering the sintered wick after the first sintering, there is a disadvantage that a change in shape, size, porosity, and transmittance due to shrinkage of the sintered wick is inevitable.

In addition, according to the conventional method of manufacturing an evaporator for a loop heat pipe system, the manufactured evaporator reduces the contact area between the sintered wick and the heating plate due to the presence of a vapor passage (microchannel), so that the value of the contact conductance is relatively small. There are also disadvantages. That is, referring to FIG. 3, which schematically illustrates a cross section of a state in which a heating plate 122 and a sintered wick 120 having a steam passage 126a are coupled to each other in a cross sectional direction that is 90 degrees from the cross sectional direction of FIG. 2. In this case, the size of the contact surface 126b in contact with the sintered wick 120 and the heating plate 122 is reduced by the vapor passage 126a, and thus, the amount of heat that can be transferred is also insufficient.

The present invention has been proposed to solve the above problems, in the method of manufacturing an evaporator for a loop bottom pipe system, the manufacturing process is simple and the manufacturing cost is low, and the bonding state between the heating plate and the metal sintering wick is improved. It is an object to provide a method of manufacturing an evaporator with an increased value of contact conductance.

The method of manufacturing an evaporator for a loop heat pipe (LHP) system of the present invention includes a groove processing step of processing a groove groove of a fan string concave and elongated on one side of a heating plate made of a metal material; A groove filling step of filling a groove of the heating plate with a groove filling material including a sublimable solid material; A jig providing step including a jig positioned to be spaced apart from one side of the heating plate on which the groove is formed; A metal powder filling step of filling a metal powder in a space formed between one side of the heating plate and the jig; And a sintering step of forming the porous sintering wick by heating the metal powder so as to be sintered.

On the other hand, the sublimable solid material is preferably naphthalene.

On the other hand, the groove filling material preferably comprises an organic solvent aqueous solution.

In addition, the organic solvent aqueous solution preferably contains at least one of ether and alcohol.

On the other hand, the metal powder is nickel and the heating plate is copper, the sintering step,

And a heating section for raising the starting temperature to the holding temperature, a temperature holding section for holding the holding temperature for a predetermined holding time, and a cooling section for cooling the holding temperature from the holding temperature to the starting temperature. The heating time is 10 minutes or less, the heating rate is 60 ~ 80 ℃ / min, the temperature holding interval, the holding temperature is in the range of 600 ~ 800 ℃, the holding time is 5 ~ 30 min range In the cooling section, the duration is 30 to 60 min, and the sintering environment is preferably a vacuum or inert gas atmosphere in the range of 10 ^-3 Torr.

On the other hand, in the groove processing step, the groove is spaced apart to face both sides and the bottom surface, the both sides are processed to have a predetermined height, in the groove filling step, the groove filling material is the groove of the groove It is preferable to fill at least the upper end of both sides.

In addition, in the groove filling step, the top surface of the groove filling material filled in the groove is preferably any one of a convex up, a convex down and a flat shape.

According to the method of manufacturing the evaporator of the present invention, since the sintered wick is formed as well as the sintered wick is formed by simply placing the metal powder on the heating plate and undergoing one sintering process, the manufacturing process is simple and thus As a result, manufacturing cost can be reduced.

In addition, according to the method of manufacturing the evaporator of the present invention, since the metal powder is directly bonded to the heating plate while being sintered, the contact conductance value is increased since the bonding state of the bonding interface between the sintered fin and the heating plate is significantly better than in the related art. The effect can be obtained.

The present invention relates to a method for manufacturing an evaporator which forms a loop heat pipe system together with a condenser, a gas conveying tube and a liquid conveying tube.

For reference, the overall configuration of the loop heat pipe system 200 including the evaporator 1 manufactured by the present invention will be schematically described with reference to FIG. The loop heat pipe system 200 includes an evaporator 1, a condenser 210, a gas transfer tube 220, and a liquid transfer tube 230.

The condenser 210 is a place where the working fluid of the gaseous state received from the evaporator 1 is phase-changed into a liquid. The condenser 210 takes heat from the working fluid and sends it to the outside atmosphere. The gas transfer pipe 220 is a pipe member connecting the evaporator 1 and the condenser 210 so that the gas phase changed in the evaporator 1 is transferred to the condenser 210, the liquid transfer pipe 230 is a condenser It is a pipe member connecting the condenser 210 and the evaporator 1 so that the liquid phase-changed at 210 can be supplied to the evaporator 1 again. On the other hand, with respect to the general description and operation of the entire system 200, the condenser 210, the gas transfer pipe 220 and the liquid transfer pipe 230, what is described above in the background art is applied as it is.

Hereinafter, a method of manufacturing an evaporator for a loop heat pipe system according to an embodiment of the present invention will be described with reference to FIGS. 6 to 14.

The method for manufacturing an evaporator for a loop heat pipe system according to the embodiment includes a groove processing step (S1), a groove filling step (S2), a jig preparing step (S3), a metal powder filling step (S4), and a sintering step (S4). It is configured to include.

The groove processing step (S1) is a step of processing a groove (groove) of the groove shape of the fan string concave and long on one side of the heating plate 10 of the metal material.

In FIG. 7, the heating plate 10 of the metal material on which the groove 20 is processed is shown in a schematic sectional view.

The heating plate 10 is made of metal and receives heat from a heat source such as an electronic component that generates heat during operation.

In the present embodiment, the heating plate 10 is composed of a lower plate portion 12 and a wall portion 14. The lower plate portion 12 has a disc shape, and the wall portion 14 extends upward from the circumference of the lower plate portion 12. The lower plate part 12 and the wall part 14 may be integrally formed, or may be provided as separate members, respectively, and the grooves 20 may be coupled to each other after being processed.

For reference, the lower surface of the lower plate portion 12 receives heat from the contact with the heat source. The heat transferred to the lower plate portion 12 is also transmitted by conduction to the wall portion 14 connected to the lower plate portion 12. On the other hand, in the present embodiment, the "one side" of the heating plate 10 has the same meaning as the "inner side" pointing together the inner surface facing the upper surface of the lower plate portion 12 and the inside of the wall portion 14.

The groove processing step (S1) is a step of processing a plurality of grooves 20 having a concave and elongated fan string shape by using a machine tool such as a lathe on one side of the heating plate 10.

On the other hand, the gas transfer pipe 220 is connected to the heating plate 10 is also processed to the outlet 18 through which the gas can flow, each groove 20 is processed to communicate with such an outlet (18). Only after this process, the gas generated in the groove 20 may flow out of the gas delivery pipe 220 via the outlet 18.

In the present embodiment, the grooves 20 are processed to be spaced apart from each other at regular intervals. Each groove 20 is processed in the form of a groove to have both side surfaces 24 and the bottom surface 22 facing each other at a distance. Both sides 24 of the groove 20 are symmetrical with respect to the mutual center axis and have a predetermined height. On the other hand, in the present embodiment, the grooves 20 formed in the lower plate portion 12 are all the same in the form of a straight line formed long, but because the lower plate portion 12 is circular, each length is symmetric with each other based on the center of the lower plate portion Each pair becomes the same and is processed differently than the others.

The grooves 20 formed in the wall portion 14 are processed along the inner surface of the wall portion 14. Each groove formed in the wall is generally a ring shape. In addition, the grooves 20 formed in the wall portion 14 are also processed to communicate with the outlet 18.

As in the case of the present embodiment, when the lower plate portion 12 and the wall portion 14 of the heating plate 10 are formed as separate members, the grooves 20 are processed on each member, and then the two members are joined. However, when the lower plate portion and the wall portion are integrated, the grooves are processed sequentially or simultaneously in one process.

Next, groove filling step S2 is performed.

The groove filling step S2 is a step of filling the grooves 20 including the sublimable solid material in each groove 20 formed in the heating plate 10.

The groove filling material 30 is filled over the entire length of the groove 20. Referring to FIG. 8, which shows an imaginary cross section perpendicular to the longitudinal direction of the groove, the filling material 30 is filled in the groove 20 to have a constant cross section.

The groove filling material 30 maintains its shape in a filled state at room temperature. Therefore, when the metal powder is filled in the groove in the next step, the metal powder filling step (S4), the metal powder is filled in the remaining space of the groove except the space occupied by the groove filling material. That is, the reason why the groove is filled with the groove filling material is to prevent the metal powder from penetrating into the space serving as the steam passage in the groove in the metal powder filling step (S4).

The groove filling material 30 contains a sublimable solid material. The sublimable solid material is in a solid state at room temperature and undergoes a phase change from a solid state to a gaseous state as it is heated in the sintering step, is converted into a gas, and then discharged to the outside. In the case of this example, the sublimable solid material is naphthalene. However, in addition to naphthalene, the sublimable solid material may be replaced with another material having the property of sublimation and capable of maintaining its form at room temperature.

Meanwhile, in the present embodiment, the groove filling material 30 includes an organic solvent aqueous solution. When the groove filling material 30 contains an organic solvent aqueous solution and the amount thereof is appropriately adjusted, it is possible to adjust the vaporization time of the sublimable solid material to a desired degree. Considering that the metal powder is sintered in the sintering step, and when the evaporation time of the sublimable solid material can be controlled, the shape of the lower surface of the penetration portion penetrated into the groove 20 in the sintered wick formed by sintering is variously controlled. It becomes possible. That is, even though the groove 20 is filled with the groove filling material 30 horizontally as shown in FIG. 8, the metal powder is filled and then sintered, the shape after the sintering is as shown in FIGS. 11 and 12. Can be convex or up.

As the aqueous organic solvent, either one of ether, alcohol, or a mixture of two may be used.

However, according to the embodiment, the groove filling material 30 may not include the organic solvent aqueous solution, but may be made of only a sublimable solid material.

In addition, in the present embodiment, the groove filling material 30 is filled except at least the upper end portions of both side surfaces 24 of the groove 20. Referring to FIG. 8, the groove filling material 30 is filled only up to about two thirds of the height of the groove 20, and the upper portion of the groove 20 is empty. In other words, the groove filling material 30 is filled in a part including the lower part except the upper part of the groove 20, not the whole part.

Meanwhile, in some embodiments, the groove filling material 30 may be filled in the entire space of the groove 20.

Meanwhile, in the present embodiment, the top surface of the groove filling material 30 filled in the groove 20 is flat, but in another embodiment, the top surface of the filling material filled in the groove is convex upward or downward convex. It may be modified to be. That is, in consideration of the shape of the metal powder to be filled later and the shape of the sintered metal wick, the upper surface of the filling material may be deformed into a desired shape within the possible range in view of the properties of the filling material.

As described above, the shape of the lower surface of the groove penetrating portion of the metal sintered wick formed by sintering may be adjusted by including the aqueous solution of the organic solvent in the filling material, but the shape of the lower surface is controlled by adjusting the shape of the upper surface of the filling material. It could be.

Next, the jig providing step (S3).

A jig 40 is disposed to be spaced apart from one side of the heating plate 10 on which the groove 20 is formed.

As shown in FIG. 9, the jig 40 faces a side where the grooves 20 are formed in the heating plate 10 and is spaced apart from each other at a predetermined interval, so that the metal powder is filled between the heating plate 10 and the heating plate 10. ) Is provided to ensure. The jig 40 positioned to be spaced apart from one side of the heating plate 10 may be divided into two or more suitable numbers according to the embodiment. In the present embodiment, the jig 40 is composed of four divided split jigs 402, 403, 404, 405. The lower subsidiary jig 401 is used to assist the lower portion of the heating plate 10. The jig 40 and the lower auxiliary jig 401 are both made of carbon graphite.

The metal powder filling step (S4) is a step of filling the metal powder in a space 410 formed between one side of the heating plate 10 and the jig 40. The metal powder filling step (S4) is not usually performed after the jig providing step (S3) is completely performed. First, the jig may be formed between the one side of the heating plate 10 and the jig 40. After is provided, after filling the metal powder in the space 410, the remaining jig is provided. In the present embodiment, two jigs 402 and 404 are provided at the intended positions after the metal powder 50 is filled in the space 410 (see FIG. 10).

The jig 40 is preferably configured to be hardened by appropriately pressing the filled metal powder.

The number of divisions of the jig 40 or the order of filling the metal powder in the space 410 may be variously modified as long as the space filled with the metal powder is maintained as shown in FIG. 10.

The sintering step (S5) is performed after the jig providing step (S3) and the metal powder filling step (S4) is completed.

The sintering step (S5), the metal powder 50 is heated to a temperature close to the melting point, the metal powder 50 is bonded to each other in contact with each other or a part is deposited by being connected to each other to form a large number of pores therein Is a lump to form a porous sintering wick. In particular, in the case of the evaporator manufacturing method according to the present invention, the metal powder is sintered wick and at the same time, the bonding is made to one side of the heating plate 10 of the metal material. That is, not by a separate process, but sintering of metal powder and bonding to a heating plate are performed by one process.

The heating temperature is appropriately determined according to the metal powder used. As shown in FIG. 10, the metal powder 50, the jig 40, and the heating plate 10 are heated in a mutually coupled state.

Meanwhile, in the sintering step S5, the groove filling material 30 filled in the groove 20 is sublimed. Therefore, when the sintering is completed, the groove 20 is the place where the groove filling material 30 is located in the empty space to serve as a passage of the steam.

As described above, it is possible to control the shape of the lower surface of the sintered wick portion penetrated into the groove 20 by including the organic solvent aqueous solution in the groove filling material 30 to adjust the sublimation time of the sublimable solid material. . In addition, by adjusting the shape of the upper surface of the groove filling material 30, it is also possible to adjust the shape of the lower surface of the sintered wick portion penetrated into the groove 20.

In the present embodiment, the groove filling material 30 includes a sublimable solid material and an organic solvent aqueous solution.

Thus, as shown in FIG. 8, the groove filling material 30 is filled in the groove 20 so that its top surface is flat, but promotes the evaporation time and thus the groove of the sintered wick 52 as shown in FIG. 11. The shape of the lower surface of the penetrating portion 54 in the inner portion may be formed to be convex upward. And, by adjusting the amount of the organic solvent aqueous solution by controlling the evaporation time, as shown in Figure 12, the lower surface of the needle portion 55 of the sintered wick 52 may be formed convexly downward. However, the lower surface of the insertion portion of the sintered wick may not be smooth as shown in the drawing, but when viewed as a whole, it may be convex downward or convex upward.

In addition, as the groove filling material, when a sublimable solid material and an organic solvent aqueous solution are appropriately included, or when the shape of the filling material filled in the groove 20 is appropriately adjusted, as shown in FIG. In addition, the penetrating portion 56 or the insertion portion of the sintered wick 52 may be formed. In such a shape, the space for the vapor passage is also sufficiently secured, and the contact portion between the sintered wick 52 and the heating plate 10 also increases, and heat transfer is effectively performed.

On the other hand, in the sintering step (S5) of the present embodiment, with reference to Figure 14 with respect to temperature, time, sintering atmosphere and the like, it will be described in detail.

The sintering step consists of a heating section (I), a temperature holding section (II) and a cooling section (III).

The heating section (I) is a section for heating so that the temperature is increased from the start temperature (T1), which is the normal room temperature, to the holding temperature (T2). The temperature conditions vary depending on the environment conditions, the wick material, and the equipment used (e.g. furnace). The heating rate is in the range of 60 ~ 80 ℃ / min, the holding temperature is 600 ~ 800 ℃, was prepared with a holding time of 5 ~ 30 min. The conditions presented are those for securing the air permeability of the formed sintered wick 60% or more. On the other hand, the range of temperature conditions may vary depending on the target porosity (air permeability).

The temperature holding section II is a section held for a predetermined holding time at the holding temperature T2. In this embodiment, the holding time is 5 minutes. However, the holding time can be in the range of 5 minutes or more and 30 minutes or less depending on the type of sintered metal and the holding temperature (T2).

The cooling section III is a section for cooling from the holding temperature T2 to the starting temperature T1 at room temperature. The time required for the cooling section is preferably within 30 to 60 min, and in this embodiment, it is 60 minutes.

Although it may be provided with a separate cooling means for cooling, it can be made by the natural convection cooling to the start temperature (T1) of the room temperature in the room temperature environment without heating without a separate cooling means.

In the case of the present embodiment, the surrounding environment during sintering is a vacuum in the range of 10 ⁻³ Torr or an inert gas atmosphere. In order to implement such a sintering environment, it is preferable to perform sintering in a closed chamber. 14 shows the control temperature.

In addition, the evaporator 1 is provided with a cover member 16 at the upper end of the side wall portion of the heating plate 10. The liquid transport tube 230 is coupled to the cover member 16 such that the working fluid in the liquid state from the condenser 210 flows into the internal space of the evaporator 1. The bonding process of the cover member 16 is performed after the sintering step (S5) is completed.

The effect of the evaporator manufacturing method for a loop heat pipe system of the above-mentioned structure is demonstrated.

 In the conventional method of manufacturing an evaporator, after forming a sintered body, a groove has to be formed in the sintered body, and the sintered body is bonded to a heating plate again. However, according to the method of manufacturing an evaporator of the present invention, after the metal powder is placed on a heating plate, If only one sintering process is performed, the sintering wick is formed, as well as the sintering wick is coupled to the heating plate, the manufacturing process is simple, thereby reducing the manufacturing cost.

In addition, in the conventional evaporator manufacturing method, since the simple bonding method or the metal bonding method is employed to combine the heating plate and the sintered wick, the bonding state of the bonding interface is not good, but in the case of the evaporator manufacturing method of the present invention, Since the powder is directly bonded to the heating plate while being sintered, since the bonding state of the bonding interface between the sintering fan and the heating plate is remarkably better than in the related art, the value of the contact conductance value is increased.

In addition, in the conventional evaporator manufacturing method, since the microchannel (groove) serving as a steam passage is formed in the sintered wick, the area of the contact surface with the heating plate was not sufficient, but as an embodiment of the evaporator manufacturing method according to the present invention According to the embodiment in which the groove is formed in the heating plate and the groove filling material is filled in the groove so that a part of the sintered wick penetrates into the groove, the area of the sintered sintered part is joined to both sides of the groove, so that the heating area, The area of the contact surface, also called the bonding area, is increased, which increases the value of the contact conductance. In other words, the thermal contact resistance is reduced. In addition, the amount of evaporation of the working fluid increases at the junction interface, which means that the mass flow rate (kg / g) of the steam increases.

In addition, according to the method of manufacturing an evaporator for a loop heat pipe of the present invention, there is an advantage in that the shape of the penetration portion of the sintered wick can be adjusted to a desired shape by adjusting the groove filling material. In order to control the formation of the penetrating portion of the sintered wick into the groove, an organic solvent aqueous solution may be included in the groove filling material, or the shape of the top surface of the filling material filled in the groove may be adjusted. By controlling the shape of the penetration portion of the sintered wick in the groove, there is an advantage that the cross-sectional shape of the space inside the groove serving as the steam passage can be adjusted to the desired shape.

On the other hand, the evaporator manufactured by the loop heat pipe evaporator manufacturing method of the present invention, compared to the evaporator produced by the conventional method, the contact state of the contact surface is good, the area of the contact surface is also increased according to the embodiment, the working fluid Since the area of vaporized gas is increased, the contact conductance between the sintered wick and the heating plate is high. In the case of the evaporator manufactured by the present invention, the state of the contact interface between the sintered wick and the heating plate may be distinguished by comparing the state of the contact interface by a conventional metal bonding method such as simple pressing or resintering. .

1 is a conceptual diagram of a loop heat pipe system 110 of the prior art,

2 is a schematic cross-sectional view of the evaporator of FIG. 1,

3 is a schematic cross-sectional view according to III-III of FIG.

4 is a schematic perspective view of a state in which the sintered wick of FIG. 2 is rotated 180 degrees;

5 is an overall configuration of a loop heat pipe system 200 including an evaporator 1 manufactured by the manufacturing method of the present invention.

6 is a flowchart of a method of manufacturing an evaporator for a loop heat pipe system according to an embodiment of the present invention;

7 is a schematic cross-sectional view of the heating plate 10 of the metal material, the groove 20 is processed,

FIG. 8 is a view showing a virtual cross section perpendicular to the longitudinal direction of the groove of FIG. 7;

9 is a schematic cross-sectional view of a state in which a jig is provided,

10 is a schematic cross-sectional view of a metal powder filled state in the state of FIG. 9;

11 to 13 illustrate various shapes of sintered wicks in grooves,

14 is a graph with two axes of heating time and heating temperature.

Claims (7)

A method of manufacturing an evaporator for a loop heat pipe (LHP) system, Groove processing step of processing the groove-shaped groove (groove) of the concave and elongated fan string on one side of the heating plate of the metal material; A groove filling step of filling a groove of the heating plate with a groove filling material including a sublimable solid material; A jig providing step including a jig positioned to be spaced apart from one side of the heating plate on which the groove is formed; A metal powder filling step of filling a metal powder in a space formed between one side of the heating plate and the jig; And And a sintering step of heating the metal powder so as to sinter to form a porous sintering wick. The method of claim 1, The sublimable solid material is naphthalene, characterized in that the method for producing an evaporator for a loop heat pipe system. The method of claim 1, The groove filling material is a method of manufacturing an evaporator for a loop heat pipe system, characterized in that it comprises an organic solvent solution. The method of claim 3, The organic solvent aqueous solution is a method for producing an evaporator for a loop heat pipe system, characterized in that it comprises at least one of ether and alcohol. The method of claim 1, The metal powder is nickel and the heating plate is copper; The sintering step, A heating section for raising the starting temperature to a holding temperature, a temperature holding section for holding the holding temperature for a predetermined holding time, and a cooling section for cooling the holding temperature to the starting temperature, In the heating section, the heating time, the duration of which is 10 minutes or less, the heating rate is 60 ~ 80 ℃ / min, In the temperature holding section, the holding temperature is in the range of 600 ~ 800 ℃, the holding time is in the range of 5 ~ 30 min, In the cooling section, the duration is within 30 ~ 60 min, The sintering environment is a method of manufacturing an evaporator for a loop heat pipe system, characterized in that the vacuum or inert gas atmosphere environment in the range of 10 ^-3 Torr. The method of claim 1, In the groove processing step, the groove has two side surfaces and a bottom surface facing away from each other, the both sides are processed to have a predetermined height, In the groove filling step, the groove filling material is filled except at least the upper end of the both sides of the groove, the method of manufacturing an evaporator for a loop heat pipe system. The method of claim 1, In the groove filling step, the top surface of the groove filling material filled in the groove is any one of the convex form, the convex form and the flat form, characterized in that the evaporator for a loop heat pipe system.

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