CN101394730A

CN101394730A - Split heat radiator

Info

Publication number: CN101394730A
Application number: CNA2008101032413A
Authority: CN
Inventors: 周建辉; 杨春信
Original assignee: Beihang University
Current assignee: Beihang University; Beijing University of Aeronautics and Astronautics
Priority date: 2008-04-01
Filing date: 2008-04-01
Publication date: 2009-03-25

Abstract

The invention relates to a novel radiator of an electronic device. The radial fins of the radiator are designed into branch shapes with fractal features, so that more and more branches are generated through branches, thereby greatly increasing the heat convection area with the external world, and enhancing the heat convection effect. In the specific implementation manner, longitudinal and horizontal notches are formed on radiating fins, and the lower end of a heat sinker is higher than the radiating fins. The invention has the advantages that (1) the larger space of the outer ends of the fins in the radial directions can be fully used, and more branch fins are arranged, thereby increasing the heat exchange surface area; (2) since the gaps among fins at the external ends of the fins become small, thereby having shielding effect, reducing the bypass flow of air stream among fins, and enabling more air stream to be discharged from the lower ends of the fins by passing through the fins from the upper part of the radiator; and (3) the fluid with high velocity of flow on the blade top of the outlet of a fan is fully used to participate in the heat convection.

Description

Fractal radiator

Technical field

The present invention relates to the heat abstractor that adopts air forced convection mode to cool off, the radial radiator of particularly a kind of electronic equipment of fractal structure fin. the present invention can be used for radiator the high efficiency and heat radiation design, particularly computer CPU radiator of power electronic equipment air forced convection cooling system.

Background technology

In personal computer, follow the central processing unit golf calorific value can cause that the stability of system and reliability reduce becoming increasingly conspicuous of problem, make the CPU heat radiation become the thermal design difficult point. because cost and the requirement of reliability aspect adopt the air forced convection type of cooling of fan and heat sink assembly to be widely used.

The fan impact jet flow has absolute predominance at aspects such as part cooling and quick heat radiatings, cooperates radial heronsbill radiator that the high power electronic element is cooled off, but is the effective way that solves heat dissipation problem. and radial structure has following defective:

1) the fin root radius is less than the fin top radius, and for certain thickness fin, the fin number that permission is installed at the fin root is limited, causes overall fin heat exchange area limited;

2) fin root fin is arranged closely, flow resistance is bigger, fin top spacing of fins is bigger, flow resistance is less. when air-flow enters spacing of fins, add that fan rotary centrifugal force effect air-flow is easily from the less fin top bypass of resistance, cause the actual air flow rate that contacts with the fin surface to reduce, so cause the heat convection deleterious. need be to the fin improved shape, with the utilance of raising fin with increase the actual air flow rate that pushes through between fin.

Summary of the invention

Above-mentioned shortcoming at the traditional design technology, the inventor has designed a kind of novel electronic equipment cooling device. and technical scheme of the present invention is based on the fractal structure feature, the fin of radial radiator is designed to have the tree-shaped form of bifurcation of fractal characteristic. produced increasing branch by bifurcated, make to increase considerably that the heat convection effect strengthens with extraneous heat convection area.

In order to reach above-mentioned goal of the invention, technical scheme of the present invention realizes as follows:

The radial radiator of a kind of fractal fin, it comprises fractal structure fin and heat sink, its design feature is that fin is based on the fractal structure feature.

According to an aspect of the present invention, provide a kind of radiator, comprise one heat sink and from heat sink cardinal principle along a plurality of radiated ribs that extend radially outwardly, it is characterized in that: the described radiated rib of at least a portion has fractal structure.

According to another aspect of the present invention, provide a kind of radiator, wherein, slightly be longer than described radiated rib for heat sink, with near the space of a no fin of a formation described end of heat sink close thermal source at a described heat sink end near thermal source.

According to a further aspect of the invention, provide a kind of radiator, this radiator is used for and is arranged on the fan cooperating of an end of described heat sink stow away from heat, with by the air-flow that fan was driven, takes away heat from radiated rib and heat sink.

According to a further aspect of the invention, provide a kind of radiator, wherein said radiated rib with fractal structure is provided with otch.

According to a further aspect of the invention, provide a kind of radiator, wherein said radiated rib with fractal structure comprises at least one grade of branch, and each branch has at least a in the following branch form:

A) be divided into two, and

B) one is divided into three.

In order further to realize purpose of the present invention, can also finish by the following technical programs: the fractal structure fin is centered around around heat sink, otch is in length and breadth arranged on the fin, and heat sink lower end is a little more than fin, and fractal heat radiator for electronic equipment monnolithic case is radial.

The beneficial effect that the present invention can produce: 1) can make full use of fin outer end place radially than large space, arrange more multiple-limb fin, improve the heat exchange surface area; 2) because the fin gap smaller at fin place, outer end radially, has screen effect, reduced air-flow bypass amount between fin, made more air-flows flow through fin from the radiator upper end from fin lower end discharge .3) can make full use of the big fluid participation of fan outlet vane tip flow velocity heat convection.

The present invention will be further described below in conjunction with the drawings and specific embodiments.

Description of drawings

Fig. 1 is the general illustration of a kind of fan according to an embodiment of the invention and heat spreader structures;

Fig. 2 is the isometric drawing of the fractal heat spreader structures of embodiment shown in Figure 1;

Fig. 3 is the top view of the fractal heat spreader structures of embodiment shown in Figure 2;

Fig. 4 has shown the structure of fractal fin according to an embodiment of the invention, and it has 3 grades 2 bifurcation structures;

Fig. 5 has shown the structure of fractal fin according to an embodiment of the invention, and it has 3 grades 3 bifurcation structures;

Fig. 6 has shown the structure of fractal fin according to an embodiment of the invention, and it has irregular bifurcation structure.

Embodiment

Fig. 1 is the general illustration of a kind of fan according to an embodiment of the invention and heat spreader structures.In embodiments of the invention shown in Figure 1, the use that matches with fan 1 of fractal type heat radiator for electronic equipment 2.

Fig. 2 has further shown the structure of the fractal heat spreader structures of embodiment shown in Figure 1.As shown in Figure 2, in this embodiment of the present invention, fractal type heat radiator for electronic equipment comprises heat sink 3 and fractal radiated rib 4, wherein fin 4 has fractal structure. and heat sink 3 of center heat absorption is cylindrical shapes, and heat sink 3 can be adopted the Heat Conduction Material such as aluminium or copper product. adopt the fractal radiated rib of making such as the Heat Conduction Material of aluminium or copper product 4 to be centered around around heat sink 3.

As a kind of preferred but the specific embodiment of indefiniteness as shown in Figure 2, preferably has otch 5 on radiated rib 4, with facility along radially air flows.In the embodiment of concrete but indefiniteness shown in Figure 2, otch 5 is included in otch and the otch in the first order branch of fin 4 on the outer rim of radiated rib 4; The axle of otch on the outer rim of fin 4 with respect to heat sink 3 is substantially horizontal expansion, and the otch in the first order branch of fin then is axially extended along heat sink 3 substantially.

As a kind of preferred embodiment, radiated rib 4 slightly is longer than in heat sink 3 lower end, to form the space for the no fin of air flows heat sink bottom.The monnolithic case of this fractal heat radiator for electronic equipment is radial.

Fig. 3 is the top view of the fractal heat spreader structures of embodiment shown in Figure 2.As shown in Figure 3, this embodiment has 2 grades two bifurcation structures, that is, a fin is divided into two into earlier two branches, each branch more separately secondary be branched into two branches, a final fin is divided into 4 branches altogether.

Fig. 4 has shown the structure of fractal fin according to another embodiment of the invention, and they are different with embodiment's shown in Figure 3, are that it has 3 grades 2 bifurcation structures, and promptly each fin finally has been divided into 8 branches.

Fig. 5 has shown the structure of fractal fin according to still another embodiment of the invention, and it has roughly 3 grades 3 bifurcation structures.A branch in the middle of it should be noted that among Fig. 5 has only secondary branch, and not only there is secondary branch in two branches on both sides, and also has three branches.She Ji purpose is too much to cause the fin at medial fascicle place too intensive for fear of branch like this.

Fig. 6 has shown the structure of fractal fin according to an embodiment of the invention, and it has irregular bifurcation structure.Different with the fin branched structure that Fig. 2-5 shows with the increase of class geometric progression, branch's fin number in the irregular bifurcation structure of Fig. 6 can be non-geometric progression, especially, its branch's fin number is can be with the extension of radius linear to be increased, from but the increase of the volume in the increase of branch's fin number and these branch fin spaces of living in is consistent; This spatial volume (Δ V) and radius R are linear, promptly

ΔV∝RxΔR

In the present invention, can make full use of fin top (being the radially outside side part of fin) than large space, arrange more multiple-limb fin, improve the heat exchange surface area.

Further, because fin top fin gap smaller, air-flow to fans drive has screen effect, and reduced the radial flux of air-flow between fin, make more air-flows from radiator top along heat sink axial (vertically) fin of flowing through downwards, discharge from the fin lower end. this along heat sink air current flow longitudinally, be favourable for heat radiation.Flow in order more to help this longitudinal air flow, as shown in Figure 2, as a kind of preferred embodiment, radiated rib 4 slightly is longer than in heat sink 3 lower end, to form space heat sink 3 bottom, to be convenient to arriving the air-flow of heat sink bottom more along radially scattering for the no fin of air flows.

Again further, axially and a kind of means that flow radially as shown in Figure 2,, on radiated rib 4, have vertical and transverse incision 5 along heat sink as an embodiment as the regulation and control air-flow, with facility along radially air flows.Open otch in addition and help the influence in eliminate fluid boundary layer, improve convection transfer rate.

Another beneficial effect of the present invention is can make full use of the big fluid of fan outlet vane tip flow velocity to participate in heat convection.

During design, at first determine heat sink tile height of centered cylinder and radius, according to Fig. 4 or the 5 design fractal sections of fin (N*M structure), form single fractal fin then, along the circumferential direction duplicate and can determine overall structure by longitudinal stretching.

During making, can make cutter earlier, can integral body produce fractal radiator by stretching excision to material with fractal structure.

What deserves to be explained is; according to above-mentioned technical scheme; fractal fin quantity that is adopted and thickness preferably should be decided on power and the fan of CPU, and the power consumption of CPU and fan power greatly then fin number also should correspondingly increase. and the technical scheme of Xing Chenging also belongs to protection scope of the present invention thus.

Claims

1. radiator, comprise one heat sink (3) and from heat sink cardinal principle along a plurality of radiated ribs (4) that extend radially outwardly, it is characterized in that:

The described radiated rib of at least a portion has fractal structure.

2. radiator as claimed in claim 1, wherein in described heat sink (3) near an end of thermal source, heat sink (3) slightly are longer than described radiated rib (4), with near the space of a no fin of a formation described end of heat sink close thermal source.

3. radiator as claimed in claim 1, this radiator are used for fan (1) cooperating of an end with the stow away from heat that is arranged on described heat sink (3), take away heat with the air-flow that drives by fan (1) from radiated rib (4) and heat sink (3).

4. as claim 1 or 3 described radiators, wherein said radiated rib with fractal structure is provided with otch (5).

5. as claim 1 or 3 described radiators, wherein said radiated rib (4) with fractal structure comprises at least one grade of branch, and each branch has at least a in the following branch form:

A) be divided into two, and

B) one is divided into three.