KR200222465Y1 - Sintered wick structure heat pipe with parallel piped holes - Google Patents

Abstract

Various types of insertion rods 5 are placed in the center of the pipe, and a plurality of wires 6 are placed on the inner wall side of the heat pipe or between the insertion rod and the inner wall of the pipe and then between the pipe 1 and the insertion rod 5 After filling the metal powder, it is sintered for 10 minutes to 3 hours in a reducing atmosphere of 700 ~ 1,000 ℃ and has a sponge-like structure with fine pores.   Various wicks are formed on the inner wall of the pipe, and the insertion rods 5 and the plurality of wires 6 are drawn out to form pipe-type continuous pores, and the working fluid is injected under vacuum and sealed at the same time. A heat pipe with excellent thermoelectricity by forming a wick structure.

Description

SINTERED WICK STRUCTURE HEAT PIPE WITH PARALLEL PIPED HOLES}

The present invention relates to a heat pipe in which various wick structures of pipe-type continuous pores are formed. More specifically, a wick of metal powder sintered in the inner wall of the heat pipe is attached to the inner wall of the heat pipe. At least one fine continuous pipe is formed in the longitudinal direction (longitudinal direction) of the pipe, so that the working fluid inside the pipe forms a wick structure that further increases the moving fluid movement force by capillary action inside the wick. It is about a heat pipe.

Conventional capillary heat pipes have a working liquid injected into a pipe having a thin or thin mesh or digging a fine groove, or digging a fine groove, and then attaching a thin and thin metal mesh and sealing the pipe with a vacuum. Has been used. When one end of the pipe is heated with an external heat source, the gas generated by the evaporation of the working liquid in the heated portion moves to the unheated portion, transferring latent heat of evaporation around the pipe, causing condensation. Continuous heat transfer is achieved by returning to the heating zone in a mesh or groove and evaporating again.

Heat pipes using dense mesh are widely used, but they have to be adhered to dense metal mesh on the entire inner wall of the pipe, which makes the heat pipe thin and long, expensive, difficult to process and heat transfer when the heat pipe needs to be bent. There was a problem that did not go well.

To solve this problem, a heat pipe using a partial wick has been developed, but also an operation problem occurs when the heating part is higher than the heat dissipation part.

In addition, the heat pipe using the fine groove is very excellent in the movement of the liquid by the capillary phenomenon in the longitudinal direction of the pipe, but the movement of the liquid in the circumferential direction of the pipe is not smooth. Therefore, when evaporation or condensation occurs in the circumferential direction, the distribution of the returning liquid is not uniform in the circumferential phase. Therefore, there is a liquid-free portion in the circumference of the heating portion. In order to prevent this phenomenon, a method of covering a fine metal mesh with a fine groove has been used. The heat pipes, which combine these fine grooves and tight meshes, have shown very good results in various performances, but this method is also uneconomical due to process difficulties and extreme price increases.

In order to solve the above problems, the present invention is to improve the structure of various wicks, unlike the structure of the conventional wick,

First, the problem of heat pipes using dense grooves and fine meshes or a combination of both is improved by a wick structure with pores and pipe-type continuous pores present in the sintered metal powder. It is to provide a heat pipe excellent in conductivity.

Secondly, the heat pipe of the present invention has fine pores and pipe continuous pores attached to the inner wall of the pipe or formed inside the wick, so that the heat pipe in the longitudinal direction and the circumferential direction is more than the prior art using the fine groove or the fine mesh. The present invention provides a heat pipe in which liquid movement due to capillary action is significantly increased.

Third, when manufacturing a heat pipe, the prior art manufactures a wick in advance and inserts it into a pipe. However, in the present invention, a heat pipe is manufactured by inserting a rod, a wire, and a metal powder into a pipe at once and heating the same. Since there is no need for this, the manufacturing process is easy and the production cost of the product is low to provide a competitive heat pipe.

1 is a state in which the insertion rod and the wire is withdrawn in the present invention is formed pipe continuous pores

2 is a state in which the insertion rod and the wire is inserted in the present invention

Figure 3 is a state taken out by inserting only the insertion rod in the present invention

4A, 4B are partial cross-sectional views of FIG.

Figures 5a, 5b is a partial cross-sectional view of Figure 2

6A and 6B illustrate various implementations of the insertion wire

7a, 7b ~ 14a, 14b wick structure of various forms

<Description of Symbols for Major Parts of Drawings>

1 ..... copper pipe 4 ..... evaporator gas passage

2 ..... Metal powder sintered body (Wick) 5 ..... Insert rod

3 ..... pipe continuous pore 6 ..... wire

7a, 7b ... various pipe continuous holes

In order to achieve the above object, the present invention forms a wick structure having pipe-type continuous pores, and various types of insertion rods are positioned at the center of the pipe, and a plurality of various types of insertion wires are formed on the inner wall side of the heat pipe and the insertion rods. After placing the metal powder between the pipe and the insert rod, and sintering for 10 minutes to 3 hours in a reducing atmosphere at 700 ~ 1000 ℃, sponge type wick with 50% of the metal specific gravity Attached to and withdrawing the various insertion rods 5 and the plurality of wires 6 to form a variety of wick structure with pipe-type continuous pores. The heat pipe is completed when the formed wick structure is sealed while injecting a working fluid under vacuum.

The various insertion rods use materials such as Al ₂ O ₃ , stainless steel, silicon nitride, and the like, which have strong heat resistance, and wires use 0.1 to 1 mm. If the thickness of the wire is 0.1mm or less, the iron wire is too thin, which leads to a process difficulty, and when the thickness of the wire is 1mm or more, the evaporation gas moving path is reduced, thereby reducing the heat transfer capacity and the osmotic pressure action of the heat pipe.

The temperature for sintering the metal powder to form the wick structure in various forms is  700-1,000 degreeC, and preferable temperature is about 850-950 degreeC. If the temperature is 700 ° C or lower, the sintering time is delayed, and if the temperature is 1,000 ° C or higher, the copper powder may be melted, and thus the wick structure cannot be formed. In order to prevent oxidation, sintering is performed in a reducing atmosphere furnace for 10 minutes to 3 hours, but sintering is not performed within 10 minutes, and when the copper powder is melted for 3 hours or more, it is difficult to form fine pores.

The particle diameter of the metal powder uses spherical particles having a size of 40 microns to 1,000 microns, preferably 100 microns to 400 microns. In some cases, in order to make the sintering faster, it is possible to use a powder of 1-5% alloy of tin in copper or a powder of 1-5% of zinc in copper. And the working fluid uses a liquid such as water, methyl alcohol, acetone excellent in thermal conductivity.

Hereinafter, with reference to the accompanying drawings and embodiments will be described in detail.

Figure 1 shows a cross-sectional structure of a heat pipe sintered with metal powder and the inside of the wick has a pipe-type continuous pores in the longitudinal direction of the pipe, (2) is a sintered metal powder and (3) is a sintered metal powder wick It is a tiny hollow hole inside, which runs from the pipe evaporation section to the condensation section. (4) is a passage through which the vaporized gas moves.

2 shows a cross-sectional view of a pipe equipped with a tool rod for sintering metal powder inside the pipe. (5) is made of Al ₂ O ₃ , which is a ceramic material that does not adhere when sintering metal powder, or stainless steel, which is a steel material, and the metal powder is inserted into the pipe with the tool rod, wire, and pipe standing vertically. After filling between the rods and sintering by heating and drawing out the inserting rod 5 and the wire 6, the cross-sectional structure of the pipe as shown in FIG. 1, that is, (3) and (4) Since the pipe becomes empty, the metal powder and the inner wall of the pipe are sintered to form a sponge-like metal powder on the inner wall.

Next, if only the insertion rod 5 is used without inserting the wire 6, the structure of the wick is formed by the most compact sintered powder as shown in FIG. In addition, when inserting various types of positive and negative insertion rods, FIGS. 7A-7B, 8A-8B, 9A-9B, 10A-10B, 11A-11B, 12A-12B, 13A-13B, and FIG. Various types of wick structures can be formed, such as 14a-14b.

The position of the wick type wire 6 may be in contact with the inner wall of the pipe as shown in FIGS. 5A and 5B or may be inside the powder wick.

The wire lead-out part is composed of pipe-type continuous pores, and there may be a plurality of wires according to the number and thickness and shape of the wire, and the shapes thereof are various shapes such as circular, square, rhombus, and triangular as shown in FIGS. 6A and 6B. They are formed by sintering on the inner wall side of the heat pipe or between the insertion rod and the inner wall of the pipe.

The wick structure is costly and time consuming to manufacture the first insertion rod (tool), but this cost can continue to use the insertion tool (tool), it is possible to manufacture the heat pipe at a low price in mass production. In addition, the finely connected sponge-like structure generated by sintering causes a significantly improved capillary phenomenon than other types of wick structures, thereby increasing the heat transfer efficiency of the heat pipe more than that of the conventional heat pipe.

Example 1

Oxygen-free copper pipes with an outer diameter of 13 mm and a length of 30 cm are erected vertically, and then the Al ₂ O ₃ rods with a diameter of 8 mm and the 12 diameter 0.5 mm stainless steel wires are placed vertically and placed in the center of the pipe, between the pipe and the ceramic tool. After filling 100 micron to 400 micron size copper powder and sintering for 30 minutes to 2 hours in a reducing atmosphere furnace at 850 to 950 ° C., the ceramic tool and the wire are removed. As shown in (4), the pipe-type continuous pores become empty, and a sponge-shaped wick having approximately 50% of the copper specific weight is attached to the inner wall of the pipe in a sintered state. When the wick is vacuumed and the working fluid is injected and sealed at the same time, the heat pipe forming the wick structure of the continuous pipe type is completed.

In the prior art, the manufacturing process is complicated by manufacturing a heat pipe by making a wick in advance and inserting the pipe into the pipe, but in the present invention, as described above, the metal powder is filled between the inner wall and the insertion rod and the wire or between the inner wall and the insertion rod of the pipe. The process is simpler than the prior art by sintering the metal powder to be attached to the inner wall of the pipe by heating it, and forming the pipe-type continuous pores using the wire. In addition, the heat transfer effect is much better, and in the prior art, there is a space between the pipe and the wick so that heat is transferred through this space, that is, heat is transferred in an indirect manner. Directly through the wick attached to the pipe and through the wick Directly discharged to the pipe, so the effect is composed of heat transfer at a very rapid rate.

Claims (4)

Insertion rod (5) is located in the center of the pipe, a plurality of wires (6) is placed on the inner wall side of the heat pipe, and then filled with metal powder between the inner wall of the pipe and the insertion rod 10 in a reducing atmosphere of 700 ~ 1000 ℃ When sintering for 3 minutes to 3 hours, a sponge-type wick with fine pores is attached to the inner wall surface of the pipe, and when the insertion rod 5 and the plurality of wires 6 are drawn out, a wick structure with pipe-type continuous pores is formed. And a wick structure of the pipe-type continuous pores, wherein the pipe of the wick structure is sealed while simultaneously injecting a working fluid under vacuum. According to claim 1, the insertion rod is a variety such as 7a-7b, 8a-8b, 9a-9b, 10a-10b, 11a-11b, 12a-12b, 13a-13b, 14a-14b Heat pipe, characterized in that to form a wick structure of the form. The heat pipe according to claim 1, wherein a plurality of wires of various shapes as shown in FIGS. 6A and 6B are positioned between the inner wall side of the pipe, the inner wall side of the pipe, and the insertion rod. 2. Heat pipe according to claim 1, characterized in that only the rods (5) of various shapes are positioned and sintered in the center of the pipe without inserting the wire (6).