CN2656925Y

CN2656925Y - Hot pipe

Info

Publication number: CN2656925Y
Application number: CN 200320117731
Authority: CN
Inventors: 林志泉; 陈杰良
Original assignee: Hongfujin Precision Industry Shenzhen Co Ltd; Hon Hai Precision Industry Co Ltd
Current assignee: Hongfujin Precision Industry Shenzhen Co Ltd; Hon Hai Precision Industry Co Ltd
Priority date: 2003-11-01
Filing date: 2003-11-01
Publication date: 2004-11-17
Anticipated expiration: 2013-11-01

Abstract

The utility model relates to a heat pipe which comprises a pipe shell, a capillary wick and a proper amount of working fluid sealed in the pipe shell, wherein, the capillary attaches] closely to the inner wall of the pipe shell, which comprises a carbon nanometer tube layer; and the working fluid is a suspension that comprises a kind of liquid and a plurality of nanoscale particles with high heat conduction performance. The nano-size particles comprise a nanometer carbon ball and a amount of metal powders with high heat conduction performance wherein, a metal with high heat conduction performance is filled in the nanometer carbon ball to further improve the heat conduction performance of the working fluid. The utility model which provides the heat pipe has the advantages of having high heat conduction efficiency and being suitable for heat dissipating elements in electronic devices.

Description

Heat pipe

[technical field]

The utility model relates to a kind of conductive structure, particularly a kind of heat pipe.

[background technology]

Heat pipe is the heat-conductive assembly that dependence self internal work fluid phase transformation realizes heat conduction, and it has good characteristics such as high-termal conductivity, good isothermal, and good heat conduction effect is widely used.

Electronic technology develops rapidly in recent years, the high frequency of electronic device, high speed and integrated circuit intensive and microminiaturized, make unit volume electronic device caloric value increase severely, and hot pipe technique is fit to solve the heat dissipation problem that present electronic device is derived because of performance boost with its excellent heat conductivity performance.

As shown in Figure 1, typical heat pipe 10 by shell 11, imbibition core 12 (capillary structure) and be sealed in the pipe in working fluid 13 form.The making of heat pipe 10 is sealed after being full of working fluid 13 in the imbibition core 12 of being close to inside pipe wall filling after being evacuated in the pipe with suitable working fluid 13, making earlier usually.One end of heat pipe 10 is evaporator section (bringing-up section), and the other end is condensation segment (cooling section), can arrange the adiabatic section between evaporator section and condensation segment according to application need.Working fluid 13 evaporation gasifications form steam 14 in the imbibition core 12 when heat pipe 10 evaporator sections are heated, steam 14 is at the dirty condensation segment to heat pipe 10 of slight pressure difference effect, condense into working fluid 13 and emit heat, working fluid 13 relies on capillarity to flow back to evaporator section along imbibition core 12 again.So circulation, heat 15 constantly reaches condensation segment by the evaporator section of heat pipe 10, and the low-temperature receiver of the Duan Yiduan that is condensed absorbs.

For heat pipe 10 is normally worked effectively, require the capillary performance of imbibition core 12 good usually, working fluid 13 is uniformly distributed in the heat pipe 10, and can makes working fluid 13 rapid condensation and backflows, require working fluid 13 heat of gasification height, thermal conductivity factor big simultaneously.

On November 12nd, 2002, the United States Patent (USP) of bulletin disclosed a kind of heat pipe the 6th, 478, No. 997, and this heat pipe adopts carbon fiber to make capillary wick.The carbon fiber capacity of heat transmission is strong, and cost is low.But this patent does not disclose the size of carbon fiber, and thick carbon fiber capillary performance is undesirable, is unfavorable for heat pipe work fluid rapid condensation and backflow, thereby causes heat pipe hydraulic fluid back-flow velocity slow, and heat pipe for thermal conductivity efficient reduces.

For heat pipe work fluid, conventional art generally adopts common liq as working fluid, but general liquid thermal conductivity factor is less, makes that the heat transmission is slower, thereby makes that heat pipe for thermal conductivity efficient is lower, also might produce hot-spot at evaporator section especially.

Therefore, provide that a kind of imbibition core capillary performance is good, the heat pipe of working fluid heat transfer efficiency height is real is necessary.

[utility model content]

For solving the technical problem that the capillary performance is undesirable, the working fluid heat transfer efficiency is low of heat pipe capillary imbibition core in the prior art, the purpose of this utility model is to provide the heat pipe that a kind of imbibition core capillary performance is good, the working fluid heat transfer efficiency is high.

Heat pipe provided by the utility model comprises shell, capillary wick and is sealed in the interior an amount of working fluid of shell.Wherein capillary wick is formed at the heat pipe inwall, and it comprises a carbon nanotube layer; Working fluid is a kind of suspension, it comprises a kind of liquid and is suspended in nano-scale particle in the liquid, this nano-scale particle has high thermal conductivity, comprise the contour conductive metal powder of nano carbon microsphere or copper, the polyhedron carbon that this nano carbon microsphere is made up of with spherical structure in the ball the multilayer graphite linings bunch, its inside can be filled with the high-termal conductivity metal.

Compared with prior art, heat pipe provided by the utility model has the following advantages: heat pipe capillary imbibition core comprises carbon nanotube layer, and the CNT capacity of heat transmission is strong, and size is little, and the capillary performance is good, helps working fluid rapid condensation and backflow; Comprise nano-scale particle in the working fluid of heat pipe with high thermal conductivity, because gravity, Blang's power (Brown force) and and liquid between the frictional force effect, the relative sliding velocity with liquid of nano-scale particle is non-vanishing, thereby in liquid, do random motion, nano-scale particle has high-termal conductivity simultaneously, thereby improve the capacity of heat transmission of heat pipe work fluid, and then improve the heat transfer efficiency of heat pipe.

[description of drawings]

Fig. 1 is the operation principle schematic diagram of prior art heat pipe.

Fig. 2 is the utility model heat pipe structure radial section schematic diagram.

Fig. 3 is the nano carbon microsphere structural representation that adds in the utility model heat pipe work fluid.

Fig. 4 is the shell material schematic diagram of preparation the utility model heat pipe.

[specific embodiment]

Below in conjunction with illustrating heat pipe embodiment provided by the utility model is described:

As shown in Figure 2, heat pipe 20 provided by the utility model comprises shell 21, capillary wick 22 and is sealed in the interior an amount of working fluid of shell (figure indicates).

Shell 21 of the present utility model is that rectangle (long 10 millimeters, wide 5 millimeters), pipe range are 80 millimeters copper pipe for radial section.

According to different needs, shell 21 also can be steel pipe, aluminum pipe, carbon steel pipe, stainless steel tube, iron pipe, nickel pipe, titanium pipe or its compo pipe.Shell 21 radial sections can be standard circular, can also be other shapes, as ellipse, square, triangle, rectangle etc.

Shell 21 calibers are generally 2 millimeters～200 millimeters, and pipe range can be from several millimeters to tens of rice.

Capillary wick 22 is close to and is formed at inner wall of tube shell, and it comprises a carbon nanotube layer, and wherein carbon nanotube layer contains SWCN, multi-walled carbon nano-tubes or its combination, and thickness is 100 nanometers～100 micron.

As shown in Figure 3, present embodiment adopts pure water as working fluid, and add nano carbon microsphere 30 to improve its heat conductivility, the polyhedron carbon formed with spherical structure in the ball by multilayer graphite linings 31 of nano carbon microsphere 30 bunch wherein, and the nano carbon microsphere 30 inner metals 32 of filling, metal 32 comprises that copper, aluminium, gold, silver etc. have the metal of the high capacity of heat transmission.Nano carbon microsphere 30 particle size range are 20 nanometers～60 nanometers, and the mass content in pure water is 1.0%～3.0%, evenly disperse and are suspended in the pure water.

Nano carbon microsphere 30 also can adopt the nanometer grade powder or inner nano carbon microsphere or its combination replacement of not filling metal 32 of metal 32.

In addition, heat pipe also can adopt routine work fluids such as ammoniacal liquor, methyl alcohol, acetone or heptane, and the nano-powder that adds nano carbon microsphere 30 or high-termal conductivity metal is to improve its heat conductivility.

As shown in Figure 4, the preparation method of the heat pipe that present embodiment provided comprises:

Choose two rectangle copper sheets 41, and this identical copper sheet 41 respectively has the two side 42 of extending and forming along relative both sides downwards with same size;

Coating one deck CNT on the inwall 43 of copper sheet 41;

With two copper sheets, 41 corresponding sidewalls 42 along direction shown in the figure aim at mutually and be close to against, engaging with the nanosized copper powder sintering is one, forms complete shell 21, its inwall 43 is close to one deck CNT capillary wick 22, radial section is a rectangle;

To be evacuated in the shell 21, injection is added with the working fluid of nano carbon microsphere in right amount in shell 21, and with shell 21 sealings.

The capillary wick 22 of heat pipe 20 of the present utility model contains CNT, and the CNT capacity of heat transmission is strong, and size is little, and the capillary performance is good, helps working fluid rapid condensation and backflow; Comprise nano-scale particle in the working fluid of heat pipe 20 with high-termal conductivity, because gravity, Blang's power (Brown force) and and liquid between the frictional force effect, the relative sliding velocity with liquid of nano-scale particle is non-vanishing, thereby in liquid, do random motion, nano-scale particle has high-termal conductivity simultaneously, thereby improved the capacity of heat transmission of heat pipe work fluid, and then improved the heat transfer efficiency of heat pipe.。

Claims

1. a heat pipe comprises

The shell of one hollow;

One is close to the capillary wick that is formed at this inner wall of tube shell; And be sealed in working fluid in the shell;

It is characterized in that this mao inhaled the imbibition core and comprised a carbon nanotube layer; This working fluid is a kind of suspension, and it comprises a kind of liquid and the dispersion suspension nano-scale particle in liquid.

2. heat pipe as claimed in claim 1 is characterized in that this carbon nanotube layer contains SWCN, multi-walled carbon nano-tubes or its mixture.

3. heat pipe as claimed in claim 1 is characterized in that this CNT layer thickness is 100 nanometers～100 micron.

4. heat pipe as claimed in claim 1 is characterized in that the liquid in this working fluid comprises water, ammoniacal liquor, methyl alcohol, acetone or heptane.

5. heat pipe as claimed in claim 1 is characterized in that the nano-scale particle in this working fluid comprises nano carbon microsphere or high-termal conductivity metal-powder.

6. heat pipe as claimed in claim 5 is characterized in that polyhedron carbon that the nano carbon microsphere in this working fluid is made up of with spherical structure in the ball the multilayer graphite linings bunch, and its inside is filled with the high-termal conductivity metal.

7. heat pipe as claimed in claim 1 is characterized in that the nano-scale particle mass content in this working fluid is 1.0%～3.0%.

8. as claim 5 or 6 described heat pipes, it is characterized in that the high-termal conductivity metal comprises copper, aluminium, gold or silver-colored.

9. heat pipe as claimed in claim 1 is characterized in that the nano-scale particle particle size range is 20～60 nanometers.