HEAT PIPE WITH CAPILLARY WICK

Abstract

A heat pipe includes a casing (100) containing a working fluid therein and a capillary wick (200) arranged in an inner wall of the casing. The casing includes an evaporating section (400) at one end thereof and a condensing section (600) at an opposite end thereof, and a central section (500) located between the evaporating section and the condensing section. The thickness of the capillary wick formed at the condensing section is smaller than that of the capillary wick formed at the central section in a radial direction of the casing. The capillary wick is capable of reducing the thermal resistance between the working fluid and the casing at the condensing section.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present apparatus and method can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present apparatus and method. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is a longitudinal cross-sectional view of a heat pipe in accordance with a first embodiment of the present invention;

FIG. 2 is a longitudinal cross-sectional view of a heat pipe in accordance with a second embodiment of the present invention;

FIG. 3 is a longitudinal cross-sectional view of a heat pipe in accordance with a third embodiment of the present invention;

FIG. 4 is a longitudinal cross-sectional view of a heat pipe in accordance with a fourth embodiment of the present invention; and

FIG. 5 is a longitudinal cross-sectional view of a heat pipe in accordance with related art.

Claims

1. A heat pipe comprising: a metal casing containing a working fluid therein, the casing comprising an evaporating section and a condensing section at an opposite end thereof, and a central section located between the evaporating section and the condensing section; anda capillary wick arranged at an inner surface of the casing; whereina thickness of the capillary wick formed at the condensing section in a radial direction of the casing is smaller than that of the capillary wick formed in the central section of the casing.

2. The heat pipe of claim 1, wherein pore sizes of the capillary wick gradually increase from the evaporating section to the condensing section of the casing.

3. The heat pipe of claim 1, wherein the thickness of the capillary wick formed at the condensing section gradually decreases towards an extreme end of the metal casing remote from the evaporating section in a lengthwise direction of the casing.

4. The heat pipe of claim 3, wherein the thickness of the capillary wick formed at the evaporating section gradually increases towards the condensing section in a lengthwise direction of the casing.

5. The heat pipe of claim 4, wherein an average thickness of the capillary wick formed at the evaporating section is greater than that of the capillary wick formed at the condensing section.

6. The heat pipe of claim 1, wherein the thickness of the capillary wick formed at the condensing section is uniform and different to that of the capillary wick formed at the central section.

7. The heat pipe of claim 6, wherein the thickness of the capillary wick formed at the evaporating section is uniform and different to that of the capillary wick formed at the central section.

8. The heat pipe of claim 6, wherein the casing further comprises a tube attached to a surface of the capillary wick in the central section of the casing.

9. The heat pipe of claim 8, wherein the capillary wick is a grooved-type wick.

10. The heat pipe of claim 8, wherein the capillary wick is a sintered-type wick.

11. A heat pipe for transmitting heat from one section of the heat pipe to another section of the heat pipe comprising: a metal hollow casing containing a working fluid therein, the casing comprising an evaporating section, a condensing section and a central section between the evaporating section and condensing section; anda capillary wick formed at an inner wall of the casing, the capillary wick comprising a first capillary wick formed at the evaporating section of the casing, a second capillary wick formed at the central section of the casing and a third capillary wick formed at the condensing section of the casing, wherein a thickness of the third capillary wick is smaller than that of the second capillary wick.

12. The heat pipe of claim 11, wherein an average thickness of the third capillary wick is smaller than that of the first capillary wick.

13. The heat pipe of claim 12, wherein the thickness of the third capillary wick gradually decreases towards an extreme end of the metal casing remote from the evaporating section in a lengthwise direction of the casing.

14. The heat pipe of claim 11, wherein a thickness of the first capillary wick gradually increases towards the condensing section in a lengthwise direction of the casing.

15. A heat pipe comprising: working fluid;a metal casing receiving the working fluid therein and divided into an evaporating section, a condensing section and a central section between the evaporating and condensing sections;a wick structure attached to an inner wall of the metal casing, having a pore size gradually increased from the evaporating section toward the condensing section; whereinthe wick structure at the condensing section has an average thickness which is smaller than that at the central section.

16. The heat pipe of claim 15, wherein the wick structure at the condensing section has a gradually decreased thickness along a direction from the evaporating section toward the condensing section.

17. The heat pipe of claim 16, wherein the wick structure at the evaporating section has a gradually increased thickness along the direction from the evaporating section toward the condensing section.

18. The heat pipe of claim 15, wherein a thickness the wick structure at the evaporating section and the condensing section is uniform and smaller than that at the central section.

19. The heat pipe of claim 18, wherein a tube is attached to an inner surface of the wick structure at the central section.