KR20120086001A - Cooling system having heat pipe - Google Patents

Abstract

PURPOSE: A cooling apparatus with a heat pipe is provided to increase heat radiation and heat transfer efficiency of the heat pipe by coating carbon nanotube on wick. CONSTITUTION: A heat pipe is composed of a pipe(110) and wick(120). The pipe is the shape of a hollow form. The wick is inserted into the pipe. The wick is coated by carbon nanotube(130). The wick is composed of porous natural fabric(121) and non-woven fabric(122). The porous natural fabric is the shape of a cylinder to have a powerful suction force. The non-woven fabric surrounds the outer circumference of the porous natural fabric.

Description

Cooling System with Heat Pipe {COOLING SYSTEM HAVING HEAT PIPE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device equipped with a heat pipe, and more particularly, to a cooling device equipped with a heat pipe capable of cooling the heat generated by the heating element more quickly by using the heat pipe.

LED lighting products using high-power LEDs are mainly made of floodlights and LED street lights, and some of them are sold indoor lighting products.

LED street lamps must use a large amount of LED to obtain a high output light source, and the large amount of LED efficiency is converted into heat, which lowers the light efficiency and decreases the lifespan by increasing the junction temperature.

Therefore, there is an urgent need to improve the performance and reliability of LED devices by reducing the thermal resistance of LED street lights and security lamps by using high efficiency heat sinks.

Normally, the heat transfer path of the LED module goes through heat transfer in the LED package, convection heat transfer from the LED package to the PCB, from the PCB to the heat sink, and from the heat sink to the outside.

Recently, a technology for effectively transferring heat to the outside by using a heat pipe whose heat conductivity is 30 times faster than copper (Cu) has been developed.

In general, heat pipes have excellent heat exchange and transport capability from high temperature to low temperature, and thus, heat pipes have been used as heat elements for heat exchange and transport in electronics, communication equipment, and industrial machinery.

In particular, due to the development of chip design and manufacturing technology of electronic and communication equipment and computers, the amount of heat generated per unit volume or area is increasing due to the reduction of line width and volume.

Since heat pipes have better heat treatment performance than heat sinks / fans using air cooling, they are widely used as cooling elements in such devices, and it is expected that application cases will increase as heat generation increases.

The heat pipe-mounted cooling device has a structure in which a heating element such as an LED module is coupled to a heat sink mounted at one end of the heat pipe, so that the heat generated from the LED module is quickly moved to the other end of the heat pipe and cooled. have.

However, the conventional heat pipe-mounted cooling device has a structure in which a circuit board for supplying electricity to a heating element such as an LED module is separately manufactured from the heat sink and coupled to each other.

In this case, since the adhesion between the circuit board and the heat sink is not perfect, even if a little air layer is generated, the heat transfer efficiency is remarkably inferior.

In addition, conventional heat pipes have difficulty in miniaturization or difficult manufacturing processes, have difficulty in achieving popularization due to increased manufacturing costs in the process, and have a problem in transferring a large amount of heat.

In addition, in some cases, carbon nanotubes are mixed with a working fluid filled in the heat pipe, and in this case, the efficiency is good, but the dispersion process is not only high in difficulty, high in cost, but also repeated in high temperature heating. When the nanotubes are dispersed, the phenomenon of aggregation occurs due to fouling phenomenon that hinders heat transfer, and thus the efficiency improvement to be achieved is halved because the original function is lost.

The present invention is to solve the above-mentioned problems, to improve the heat transfer efficiency by manufacturing a circuit board and a heat sink in which the heating element is mounted integrally, and coating the carbon nanotube on the wick to increase the heat transfer and heat dissipation effect of the heat pipe It is an object of the present invention to provide a cooling device equipped with a heat pipe.

In order to achieve the above object, the heat pipe equipped with the present invention includes a heat pipe; A heating element is mounted on one surface, and the heat sink is formed around the heat pipe. The heat pipe includes: a hollow tubular body filled with a working fluid therein; A lower wick formed of a rod-shaped wick disposed inside the tubular body, the heat sink comprising a metal circuit board, the heating element being electrically coupled to one surface thereof; Heat dissipation fins are formed in the opposite direction of the heat pipe, characterized in that consisting of an upper member for coupling with the lower member.

The lower member and the upper member are mounted on one end of the heat pipe with the heat pipe interposed therebetween, and the heat sink further includes a plurality of heat sinks mounted on the other end of the heat pipe.

The lower member is provided with a lower seating groove in which the lower end of one end of the heat pipe is seated, and the upper member is formed with an upper seating recess in which the upper end of one end of the heat pipe is seated. It is formed radially around one end, and the plurality of heat sinks are spaced apart in the vertical direction of the longitudinal direction of the heat pipe.

The heat pipe is formed in a straight line, the other end of the heat pipe is positioned higher than one end.

In addition, the lower member and the upper member is formed integrally, the tube may be formed by a hole formed in the longitudinal direction of the heat sink.

In addition, the upper member is disposed on the upper portion of the lower member, the heat dissipation fins are formed to protrude in the vertical direction of the stacking direction of the lower member and the upper member, so that the heat pipe is mounted in the vertical direction in the upper member You may.

The heating element is made of an LED package and mounted on the lower member.

The wick is coated with carbon nanotubes.

The wick is compressed compressed natural fibers; It consists of a nonwoven fabric surrounding the outer circumferential surface of the porous natural fiber, the porous natural fiber and the nonwoven fabric containing the carbon nanotubes are coated.

The diameter of the wick is smaller than the inner diameter of the tube and is arranged to be flowable inside the tube, so that the wick is disposed below the tube by gravity.

The amount of working fluid is preferably 100 to 110% of the amount that the wick can absorb maximum.

According to the cooling apparatus equipped with the heat pipe of the present invention as described above has the following effects.

The lower member constituting the heat sink is made of a metal circuit board and directly coupled to the heating element so as to be electrically connected thereto, so that the circuit board and the heat sink on which the heating element is electrically mounted can be integrated to improve heat transfer efficiency.

In addition, it is possible to increase the heat transfer and heat dissipation effect of the heat pipe by coating the carbon nanotubes on the wick forming the heat pipe.

1 is a perspective view of a cooling apparatus equipped with a heat pipe according to Embodiment 1 of the present invention;
2 is a side view of a cooling apparatus equipped with a heat pipe according to Embodiment 1 of the present invention;
3 is a plan view of a cooling apparatus equipped with a heat pipe according to Embodiment 1 of the present invention;
4 is a cross-sectional view taken along line AA of FIG. 1;
5 is a cross-sectional view taken along line BB of FIG.
6 is a comparative view comparing the thermal conductivity of the heat pipe according to the first embodiment of the present invention and the conventional heat transfer material,
FIG. 7 is a view showing an example in which a heat pipe-mounted cooling device according to Embodiment 1 of the present invention is mounted on a street lamp. FIG.
8 is a perspective view of a cooling apparatus equipped with a heat pipe according to Embodiment 2 of the present invention;
9 is a cross-sectional view taken along line CC of FIG. 8;
10 is a perspective view of a cooling apparatus equipped with a heat pipe according to Embodiment 3 of the present invention;
FIG. 11 is a cross-sectional view taken along line DD in FIG. 10;

1 is a perspective view of a cooling apparatus equipped with a heat pipe according to Embodiment 1 of the present invention, FIG. 2 is a side view of a cooling apparatus equipped with a heat pipe according to Embodiment 1 of the present invention, and FIG. 4 is a plan view taken along line AA of FIG. 1, FIG. 5 is a cross sectional view taken along line BB of FIG. 1, and FIG. 6 is a cross-sectional view taken along line BB of FIG. FIG. 7 is a comparative view comparing heat conductivity of a heat pipe according to Embodiment 1 and a conventional heat transfer material, and FIG. 7 is a view illustrating an example in which a cooling device equipped with a heat pipe according to Embodiment 1 of the present invention is mounted on a street lamp.

Cooling apparatus equipped with a heat pipe of the present invention, as shown in Figures 1 to 3, the heat pipe 100 and the heat sink 200.

The heat pipe 100 is composed of a tubular body 110, the wick 120, as shown in FIG.

The tubular body 110 is formed in a hollow shape, one end and the other end thereof are closed, and the heat sink 200 is in contact with the working fluid.

The wick 120 is inserted into the inside of the tubular body 110, the outside has a uniform capillary structure and the inside is configured to have a strong suction force, fast heat transfer force and condensed working fluid quickly Return home.

The wick 120 is coated with carbon nanotubes 130.

In detail, the wick 120 is made of a porous natural fiber 121 and a nonwoven fabric 122, as shown in FIG.

The porous natural fiber 121 is formed in a cylindrical shape in a compressed state has a strong suction force.

The nonwoven fabric 122 surrounds the outer circumferential surface of the porous natural fiber 121 and has a uniform capillary structure.

By the porous natural fiber 121 and the nonwoven fabric 122 as described above, the wick 120 has a strong suction force and has a uniform capillary structure, and can be returned quickly while holding a large amount of working fluid.

Conventionally, since the material of the wick 120 is made of metal, the suction force of the working fluid is not high.

The carbon nanotubes 130 are contained and coated in the porous natural fibers 121 and the nonwoven fabric 122, thereby increasing the thermal conductivity and heat dissipation effect of the wick 120.

As shown in FIG. 6, the heat pipe 100 of the present invention is coated with carbon nanotubes 130 on the wick 120, so that the thermal conductivity of the heat pipe 100 is higher than that of the conventional heat pipe 100 as well as aluminum and copper. You can see the high.

The carbon nanotubes 130 coated on the wick 120 are 10 to 20 nanometers, and the porous natural fibers 121 and the nonwoven fabric (0.2-0.5% carbon nanotubes 130) are dispersed in water. 122) is coated on the inside and outside through the process of immersion and drying several times.

After the coating process, the carbon nanotubes 130 are coated on the entire portion of the wick 120 so that the capillary action and the absorption function of the composite structure can be superior to the conventional wick 120. have.

In addition, by wrapping the nonwoven fabric 122 on the outer circumferential surface of the compressed natural fiber 121, the elasticity is excellent, no need for a separate support rod for supporting the wick 120, the porous natural fiber 121 Has heat and chemical resistance, so it can be used without any problem in temperature and working fluid.

As described above, by forming the carbon nanotubes 130 on the wick 120, by forming the carbon nanotubes 130 in the working fluid to remove the hassle and difficulty to use, compared to the prior art used After that, the problem that the efficiency is halved by the fouling action in the working fluid can be solved.

In addition, by coating the carbon nanotubes 130 on the wick 120 having a uniform capillary pressure and strong absorption power, the thermal conductivity is improved by 40% or more than the conventional heat pipe 100, and the thermal efficiency is increased by 30% or more. Energy was saved.

On the other hand, the diameter of the wick 120 is smaller than the inner diameter of the tubular body 110 is arranged to be movable in the interior of the tubular 110, the wick 120 is always in the free state by gravity in the tubular 110 Is disposed at the bottom.

That is, the wick 120 is not fixedly coupled to the inside of the tubular body 110 and is disposed to be movable, so that the wick 120 is always disposed below the tubular body 110.

And, the amount of the working fluid in the tubular 110 is to be filled with 100 ~ 110% of the amount that the wick 120 can absorb the maximum.

When the amount of the working fluid is less than the amount that the wick 120 can absorb the maximum, the problem that the wick 120 is dried and the evaporation portion of the tube 110 is operated when the condensation unit is higher than the condensation unit There is a problem that the fluid is almost gone to the evaporation part.

In addition, when the amount of the working fluid is much greater than the amount that the wick 120 can absorb the maximum, the working fluid acts as an obstacle to heat transfer, and the effect of heat transfer is reduced.

Therefore, as in the present invention, the amount of the working fluid is to be filled to 100 ~ 110% of the amount that the wick 120 can absorb the maximum.

By filling the amount of the working fluid as described above, the working fluid is present in almost all absorbed state in the wick (120).

The heat pipe 100 as described above is formed in a straight line, it is preferable that the other end of the heat pipe 100, the heat sink 230 is mounted is located higher than one end of the heat sink 200 is mounted. Do.

The heat sink 200 has a heating element 211 mounted on one surface thereof, and surrounds the heat pipe 100.

The heat sink 200 includes a lower member 210, an upper member 220, and a heat sink 230.

The lower member 210 is formed of a metal circuit board and is disposed below the heat pipe 100, and the heating element 211 is electrically coupled to a lower surface thereof.

The upper member 220 is disposed above the heat pipe 100 and is coupled to the lower member 210 with one end of the heat pipe 100 interposed therebetween to form the heat pipe together with the lower member 210. Wrap one end of 100.

A plurality of heat dissipation fins 221 are formed on the upper member 220, and the heat dissipation fins 221 are radially formed about one end of the heat pipe 100.

The lower member 210 is provided with a lower seating groove 212 in which a lower portion of one end of the heat pipe 100 is seated, and an upper portion of one end of the heat pipe 100 is seated in the upper member 220. The upper seating groove 222 is formed.

The heating element 211 coupled to the lower surface of the lower member 210 is mounted to the lower member 210 by being made of an LED package electrically coupled to the lower member 210 made of a metal circuit board.

The heating element 211 may be formed of a semiconductor chip or the like electrically coupled to the lower member 210 while generating heat as well as an LED package.

In the present embodiment, the heat generating element 211 is made of an LED package, the heat generating element 211 is coupled to be electrically connected to the lower member 210 made of a metal circuit board, as shown in Figure 7 It was shown that it was used as a lighting device mounted on.

As described above, by directly coupling the heat generating element 211 to the heat sink 200, it is simpler than to couple the heat generating element 211 to the circuit board and then to the heat sink 200 again, as in the prior art, Since the circuit board on which the heating element 211 is mounted is the lower member 210 constituting the heat sink 200, the circuit board and the heat sink 200 are integrally manufactured to heat the heat generated by the heating element 211. It can be better transferred to the heat sink 200.

The heat dissipation plate 230 is formed of a plurality of plate material and spaced apart from each other, it is mounted on the other end of the heat pipe (100).

The heat sink 230 is mounted in the vertical direction of the longitudinal direction of the heat pipe (100).

The heat sink 200 may be made of only the lower member 210 and the upper member 220 without the heat sink 230 as necessary.

The cooling apparatus equipped with the heat pipe 100 of the present invention having the structure as described above may be applied to a street lamp as shown in FIG. 7, or may be applied to a field accordingly.

FIG. 7A illustrates a state in which the heat pipes 100 are horizontally arranged, and FIG. 7B illustrates an arrangement of the heat pipes 100 in an inclined manner, as shown in FIG. 7B. As described above, it is preferable that the other end of the heat pipe 100 is disposed to be inclined higher than one end.

The heat pipe 100 constituting the configuration of the present invention is to allow the wick 120 to flow in the tube body 110, the wick 120 is made of a porous natural fiber 121 and a nonwoven fabric 122 Since the carbon nanotubes 130 are contained on the inner and outer circumferential surfaces of the wick 120 and coated, the operation may be smoothly performed even if the condensation part, that is, the heat sink 230, is slightly lower.

This is because the porous fiber 121 has a strong suction force and the nonwoven fabric 122 has a uniform capillary, even if the heat sink 230 is slightly lower, the working fluid is the porous natural fiber 121 and the nonwoven fabric 122. The wick 120 may be easily moved to one end of the heat pipe 100.

In addition, the wick 120 is coated with the carbon nanotubes 130, so that the heat generated from the heating element 211 through the entire wick 120 due to the high thermal conductivity of the carbon nanotubes 130. By generating heat, the thermal efficiency of the heat pipe 100 can be greatly increased.

In addition, by reducing the manufacturing cost of the wick 120 by more than 50%, there is no burden for anyone to use easily, and the cost of raw materials can be reduced as much as the volume of the applied product can be reduced to obtain economic benefits.

8 is a perspective view of a cooling apparatus equipped with a heat pipe according to Embodiment 2 of the present invention, and FIG. 9 is a cross-sectional view taken along line C-C of FIG. 8.

As shown in FIG. 8 and FIG. 9, the cooling apparatus equipped with the heat pipe of the second embodiment includes a heat pipe 100 and a heat sink 200.

In the second embodiment, the heat sink 200 is integrally formed unlike the heat sink 200 of the first embodiment.

That is, in the first embodiment, the heat sink 200 is formed by coupling the lower member 210 and the upper member 220 to each other. In the second embodiment, the lower member 220 and the upper member 220 are integrally formed to heat the heat sink 200. The sink 200 is formed.

In addition, the tubular body 110 forming the heat pipe 100 is not manufactured and mounted separately, but is formed by a hole formed in the heat sink 200 in the longitudinal direction.

That is, by forming a hole in the longitudinal direction in the inside of the heat sink 200, this is the tubular body 110.

At this time, the hole forming the tubular body 110 is open at one end and closed at the other end to insert the wick 120 therein, and in the state in which the wick 120 is inserted, a separate cover 140 is provided. To close one end of the hole.

Meanwhile, a separate circuit board on which the heating element 211 is mounted may be mounted on the bottom surface of the lower member 210.

Other matters are the same as in Example 1, and detailed description thereof will be omitted.

10 is a perspective view of a cooling apparatus equipped with a heat pipe according to Embodiment 3 of the present invention, and FIG. 11 is a cross-sectional view taken along line D-D of FIG. 10.

10 and 11, the cooling apparatus equipped with the heat pipe of Embodiment 3 includes a heat pipe 100 and a heat sink 200.

The heat sink 200 includes a lower member 210 and an upper member 220.

The heating element 211 is mounted on the lower surface of the lower member 210.

In this case, a separate circuit board on which the heating element 211 is mounted may be mounted on the bottom surface of the lower member 210.

The upper member 220 is coupled to the upper portion of the lower member 210, and the heat dissipation fins 221 protrude in the vertical direction of the stacking direction of the lower member 210 and the upper member 220.

The heat pipe 100 is mounted in the up and down direction inside the upper member 220.

The heat pipe 100 is made of a tubular body 110 and the wick 120, the tubular body 110 may be manufactured separately as in Example 1 and mounted upwardly in the upper member 220. In addition, as in Embodiment 2, the upper member 220 may be formed with a hole in the upward direction, which may be a tubular body 110.

In FIG. 11, the tube 110 is manufactured separately and mounted thereon.

The lower end of the heat pipe 100 is in contact with the lower member 210 on which the heating element 211 is mounted.

Other matters are similar to those of the first embodiment or the second embodiment, and detailed description thereof will be omitted.

The cooling apparatus equipped with the heat pipe of the present invention is not limited to the above-described embodiments, and may be variously modified and implemented within the range in which the technical idea of the present invention is permitted.

100: heat pipe, 110: tube, 120: wick, 121: porous natural fiber, 122: nonwoven fabric, 130: carbon nanotube, 140: cover, 200: heat sink, 210: lower member, 211: heating element, 212: lower Seating groove, 220: upper member, 221: heat sink fin, 222: upper seating groove, 230: heat sink,

Claims (11)

A heat pipe;
The heating element is mounted on one surface, and made of a heat sink surrounding the heat pipe,
The heat pipe,
A hollow tube filled with a working fluid therein;
A rod-shaped wick disposed inside the tubular body,
The heat sink,
A lower member having a metal circuit board electrically coupled to the heating element on one surface thereof;
The heat dissipation fin is formed in the opposite direction of the heat pipe, the cooling device equipped with a heat pipe, characterized in that consisting of the upper member coupled to the lower member. The method of claim 1,
The lower member and the upper member is mounted to one end of the heat pipe with the heat pipe therebetween,
The heat sink is a heat pipe is equipped with a heat pipe further comprises a plurality of heat sinks mounted on the other end of the heat pipe. The method of claim 2,
The lower member is provided with a lower seating groove for mounting the lower end of the one end of the heat pipe,
The upper member is formed with an upper seating groove in which the upper end of one end of the heat pipe is seated,
The heat dissipation fin is formed radially about one end of the heat pipe,
The heat sink is a heat pipe is equipped with a heat pipe, characterized in that a plurality of spaced apart in the vertical direction of the heat pipe. The method of claim 2,
The heat pipe is formed in a straight line,
Cooling device equipped with a heat pipe, characterized in that the other end of the heat pipe is located higher than one end. The method of claim 1,
The lower member and the upper member is made integrally,
And said tubular body is formed by a hole formed in the longitudinal direction of said heat sink. The method of claim 1,
The upper member is disposed above the lower member,
The heat dissipation fin is formed to protrude in the vertical direction of the stacking direction of the lower member and the upper member,
The heat pipe is a cooling device equipped with a heat pipe, characterized in that mounted to the inside of the upper member in the vertical direction. 7. The method according to any one of claims 1 to 6,
The heating element is a cooling device equipped with a heat pipe, characterized in that the LED package is mounted on the lower member. 7. The method according to any one of claims 1 to 6,
The wick is a cooling device equipped with a heat pipe, characterized in that the carbon nanotubes are coated. The method of claim 8,
The wick is,
Compressed porous natural fibers;
It consists of a nonwoven fabric surrounding the outer circumferential surface of the porous natural fiber,
The porous fiber and the nonwoven fabric is equipped with a heat pipe, characterized in that the coating containing carbon nanotubes. 7. The method according to any one of claims 1 to 6,
The diameter of the wick is smaller than the inner diameter of the tube and is arranged to be flowable inside the tube,
And the wick is disposed under the tube by gravity. 7. The method according to any one of claims 1 to 6,
Cooling device equipped with a heat pipe, characterized in that the amount of the working fluid is 100 to 110% of the maximum absorbable amount of the wick.

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