Patent Application
20070235165
Many aspects of the present device 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 device. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
A vapor channel 150 is defined along an axial direction of the heat pipe 10 and is located at a center of the casing 110. The vapor channel 150 is surrounded by an inner surface of the capillary wick structure 130 so as to guide vapor to flow therein. The vapor channel 150 has a cross section which varies across its length. The vapor channel 150 comprises a nozzle 154, a diffusing channel 156 and a pair of straight channels 152, 158. The nozzle 154 is defined at a boundary between the evaporating section 120 and the adiabatic section 140. The cross section of the nozzle 154 gradually reduces towards the adiabatic section 140 to increase vapor velocity. Thickness of the capillary wick structure 130 corresponding to the nozzle 154 gradually increases towards the adiabatic section 140. The diffusing channel 156 extends from the minimum end of the nozzle 154 to a boundary between the adiabatic section 140 and the condensing section 160. The cross section of the diffusing channel 156 gradually increases towards the condensing section 160. The thickness of the capillary wick structure 130 corresponding to the diffusing channel 156 gradually reduces accordingly towards the condensing section 160. The straight channel 152 is defined at the evaporating section 120 and connects with the nozzle 154. The straight channel 158 extends from the maximum end of the diffusing channel 156 to the condensing section 160. Each straight channel 152, 158 has a uniform cross section. The thickness of the capillary wick structure 130 corresponding to the straight channel 152, 158 is uniform and of the same thickness as the straight channels 152, 158.
As the evaporating section 120 of the heat pipe 10 absorbs heat from a heat source, the working fluid contained in the evaporating section 120 absorbs the heat and evaporates, and then carries the heat to the condensing section 160 in the form of vapor. When the vapor flows through the nozzle 154, the vapor velocity is gradually increased due to the configuration of the nozzle 154. When the vapor flows through the diffusing channel 156, flow resistance of the vapor is gradually reduced due to the configuration of the diffusing channel 156, whereby the vapor can be quickly arrive at the condensing section 160 where the vapor is condensed into liquid after releasing the heat into ambient environment. Due to the difference of capillary pressure developed by the capillary wick structure 130, the condensed liquid is then sent back by the capillary wick structure 130 towards the evaporating section 120. The thickness of the capillary wick structure 130 at the adiabatic section 140 gradually increases along the flowing direction of the condensed liquid so that the flow resistance of the condensed liquid is gradually reduced. As a result, the condensed liquid can be quickly and timely sent back to the evaporating section 120. Thus, the heat resistance of the heat pipe 10 is reduced and the maximum heat transfer capacity of the heat pipe 10 is effectively enhanced.
It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 200610060224.7 | Apr 2006 | CN | national |
