CN1780543A - Hot pipe - Google Patents

Abstract

The invention consists of a tube filled with operating fluid. The tube includes heat absorption part, middle part and heat radiation part. There is capillary structure on the body of tube, and its out wall is covered through an insulation layer. When the thickness of the insulation layer meets a certain condition, the efficiency of heat absorption at absorption part and the efficiency of heat radiation at the heat radiation part are increased, and the heat lost in middle part is decreased. The invention can quickly cool the electronic component.

Description

Heat pipe

[technical field]

The invention relates to a kind of heat pipe, refer in particular to a kind of heat pipe that is applied to the heat-generating electronic elements heat radiation.

[background technology]

Heat pipe is as a kind of heat transfer unit (HTU), and it is an amount of hydraulic fluid of splendid attire in sealing low pressure heat conductivility good metal housing, and when utilizing hydraulic fluid to do in housing that vapour-liquid two is alternate to be transformed and absorb or the principle of emitting big calorimetric is carried out work.When heat pipe one end contacts the absorption heat with thermal source, hydraulic fluid in it is subjected to thermal evaporation and absorbs a large amount of heats of vaporization, the other end that the gas that forms quickly diffuses to heat pipe cools off and emits heat, form liquid after the cooling once more and reflux along inner walls, the circulation heat that thermal source can be produced is passed to the other end and distributes from heat pipe one end and so forth.For quickening the back-flow velocity of cooling back liquid, in inner walls capillary structure is set usually.Under the effect of capillary absorption affinity, quicken the back-flow velocity of liquid greatly.Because the hydraulic fluid circulation rate in the heat pipe is fast, the heat transfer efficiency height, heat pipe is used widely in the heat radiation field at present.

Though conventional heat pipe has thermal conductivity and isothermal preferably, but limited and heat pipe of hydraulic fluid and heat-generating electronic elements contact area are less in the heat pipe, the a little amount of work Liquid Absorption heat that contacts with body in the evaporation section capillary structure is only arranged, the maximal heat transfer amount of heat pipe is restricted, can not have satisfied the heat-generating electronic elements heat radiation requirement that caloric value improves constantly.

So the people in the industry utilizes change inside heat pipe capillary structure to improve Heat Transfer of Heat Pipe on Heat Pipe efficient.But heat pipe processing method commonly used at present makes capillary structure produce defective, the capillary structure of making as powder sintering method is more crisp, the interpolation screen net structure contacts defective tightness with the tube wall of heat pipe, and groove-shaped capillary structure is subjected to the instrument restriction and the groove shape and the density that process are restricted.In addition, the capillary structure difficulty of processing is big, the cost height.

In addition, along with the electronic component volume is more and more littler, it is more and more intensive to distribute, heat pipe be arranged in the restriction that is subjected to the electronic component surrounding space to a great extent.Heat pipe is easy to heat is passed to electronic component on every side when a certain electronic component is dispelled the heat, thereby temperature of electronic component around increasing influences its normal working temperature, and more serious will damage electronic component.

Therefore, more and more along with the heat-generating electronic elements caloric value, how to increase effectively that the electronic component around the heat pipe becomes the key that industry solves this type of problem in adopting heat pipes for heat transfer efficient, the protection heat-transfer path.

[summary of the invention]

The object of the present invention is to provide a kind of heat pipe that increases the electronic component around the heat pipe in adopting heat pipes for heat transfer efficient, the protection heat-transfer path.

The objective of the invention is to realize by following technical proposal:

Heat pipe of the present invention comprises that one is equipped with the body of working fluid, and this body comprises endotherm section, interlude and heat release section, and body is provided with capillary structure, and tube wall is provided with the coating layer of insulation.

Coating layer among the present invention on the heat pipe outer wall is made by insulating material, and when coating thickness satisfied certain condition, the heat transfer efficiency of heat pipe heat-absorbing section increased, and the heat release section radiating effect improves, and the interlude heat dissipation reduces simultaneously.Adopt heat pipe of the present invention can guarantee that heat effectively reaches heat release section by endotherm section, improve Heat Transfer of Heat Pipe on Heat Pipe efficient, fast cooling electronic components; Can protect the electronic component around the heat pipe in the heat-transfer path in addition.

With reference to the accompanying drawings, the invention will be further described in conjunction with the embodiments.

[description of drawings]

Fig. 1 is the generalized section of heat pipe of the present invention along axis.

[embodiment]

See also Fig. 1, heat pipe of the present invention comprises that a body 10 and that working fluid 12 is housed is coated on the coating layer 20 of body 10 outer walls.This body 10 comprises endotherm section 16, heat release section 18 and the interlude (scheming not label) between endotherm section 16 and heat release section 18, and its inwall is provided with capillary structure 14.This coating layer 20 is insulating barriers of being made by insulating material.

Caliber is R ₁ Body 10 outer walls caliber that the heat pipe behind the coating layer 20 is set be R ₂, the computing formula of its hot biography amount is as follows:

$Q=\frac{2\mathrm{\πl}(T_1-T_0)}{\ln (R_2-R_1)+k/R_2{h}_0}---\left(1\right)$

Wherein Q is the Heat Transfer of Heat Pipe on Heat Pipe amount

π＝3.1415926；

The l=pipe range;

T ₁=body 10 tube wall temperatures;

T ₀The environment temperature of=contact body 10 inner fluids;

R ₁The caliber of=body 10;

R ₂=body 10 outer walls coat the heat pipe caliber after the insulating barrier;

The coefficient of heat conduction of k=clad material;

h ₀=fluid thermal the coefficient of conductivity;

Again because of, as dQ/d R ₂=0 o'clock, Q had maximum (2)

Therefore, can be by (1), (2) formula as drawing a conclusion:

R _2c=k/h ₀, promptly the heat output of heat pipe maximum appears at R _2c=k/h ₀The place; R wherein _2cThe caliber of the heat pipe when the maximal heat transfer amount being arranged for heat pipe.

For reducing total caliber, the suitable little and h of k ₀Suitable big, so clad material should be insulating material.

The present invention promptly utilizes this phenomenon to apply on the heat pipe, and the heat pipe section in being exposed to environment coats the insulating material of low K value:

(1) works as R ₂Less than R _2cThe time can increase the caloric receptivity of heat pipe heat-absorbing section, the thermal discharge of heat release section, and to equal R _2cBe the best.Can increase the whole external heat output of heat pipe this moment;

(2) work as R ₂Greater than R _2cIn time, can reduce heat and outwards distributes, with the electronic component of heat pipe in the protection heat-transfer path.

When the electronic component caloric value is bigger, when need increasing Heat Transfer of Heat Pipe on Heat Pipe efficient, body 10 outer walls are provided with a coating layer 20, the caliber R of heat pipe after coating ₂Should get less than R _2cSituation, and with caliber R ₂Equal R _2cBe optimal cases.Be provided with this coating layer 20 with the part that body 10 is exposed to environment this moment, can strengthen the ability of endotherm section, heat release section heat transfer respectively, improves the whole outside radiating effect of heat pipe.

When electronic component distribution comparatively dense, the layout of heat pipe is subjected to electronic component spatial limitation on every side.For making heat pipe, a coating layer 20 is set, the heat pipe caliber R after coating on body 10 outer walls to wherein not damaging the electronic component around the heat pipe in the heat-transfer path in the electronic element radiating ₂Should get greater than R _2cBe provided with this coating layer 20 with body 10 interludes this moment, reduces the heat pipe interlude and outwards dispel the heat, the electronic component in the protection heat-transfer path around the heat pipe.Because the outside heat dissipation capacity of heat pipe reduces, the heat that endotherm section absorbs is sent to heat release section to greatest extent simultaneously.

The third situation be when should dispelling the heat to the big electronic component of caloric value, when protecting in the adopting heat pipes for heat transfer path around the heat pipe electronic component again, and can be in conjunction with adopting above-mentioned two kinds of schemes.Specific practice is: the part that is exposed to environment in the endotherm section and the heat release section of body 10 is provided with this coating layer 20 respectively, and makes the caliber R that coating layer 20 back heat pipes are set ₂Less than R _2c, the ability of heat absorption of increase heat pipe and heat release; Simultaneously the interlude at body 10 is provided with this coating layer 20, and makes the caliber R that the heat pipe behind the coating layer 20 is set ₂Greater than R _2c, the purpose of the electronic component around reaching in the protection adopting heat pipes for heat transfer path.

Claims (9)

1. a heat pipe comprises that one is equipped with the body of working fluid, and this body comprises endotherm section, interlude and heat release section, and body is provided with capillary structure, it is characterized in that: tube wall is provided with the coating layer of insulation.

2. heat pipe as claimed in claim 1 is characterized in that: coating layer is coated on body and exposes part in environment.

3. heat pipe as claimed in claim 2 is characterized in that: the caliber of described heat pipe satisfies following relational expression: R ₂Less than R _2c

R wherein _2c=k/h ₀, R ₂Caliber for heat pipe; h ₀Be the fluid thermal coefficient of conductivity; K is the coefficient of heat conduction of clad material; R _2cCaliber when the maximal heat transfer amount being arranged for heat pipe.

4. heat pipe as claimed in claim 1 is characterized in that: coating layer is coated on the interlude of body.

5. heat pipe as claimed in claim 4 is characterized in that: the caliber of described heat pipe satisfies following relational expression: R ₂Greater than R _2c

R wherein _2c=k/h ₀, R ₂Caliber for heat pipe; h ₀Be the fluid thermal coefficient of conductivity; K is the coefficient of heat conduction of clad material; R _2cCaliber when the maximal heat transfer amount being arranged for heat pipe.

6. heat pipe as claimed in claim 1 is characterized in that: described coating layer is coated on the endotherm section and the heat release section of body.

7. heat pipe as claimed in claim 6 is characterized in that: the caliber of described heat pipe heat-absorbing section and heat release section satisfies following relational expression: R ₂Less than R _2c

R wherein _2c=k/h ₀, R ₂Caliber for heat pipe; h ₀Be the fluid thermal coefficient of conductivity; K is the coefficient of heat conduction of clad material; R _2cCaliber when the maximal heat transfer amount being arranged for heat pipe.

8. heat pipe as claimed in claim 7 is characterized in that: described coating layer also is coated on the interlude of body.

9. heat pipe as claimed in claim 8 is characterized in that: the caliber of heat pipe interlude satisfies following relational expression: R ₂Greater than R _2c

R _2c=k/h ₀, R ₂Caliber for heat pipe; h ₀Be the fluid thermal coefficient of conductivity; K is the coefficient of heat conduction of clad material; R _2cCaliber when the maximal heat transfer amount being arranged for heat pipe.

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