Flat heat pipe

Abstract

A heat pipe a flat heat pipe having enhanced heat transport capacity is provided. The flat heat pipe 1 comprises a working fluid encapsulated in a container 2, a first wick 11 that returns the working fluid from a condensing portion 4 to an evaporating portion 3 by a capillary pumping, and a second wick 12 that spreads the working fluid returned thereto over an inner face of the container by a capillary pumping. The second wick is formed only in the evaporating portion 3 to extend in a circumferential direction on the inner face of the container2.

Description

[0001]The present invention claims the benefit of Japanese Patent Application No. 2014-146261 filed on Jul. 16, 2014 with the Japanese Patent Office, the disclosure of which is incorporated herein by reference in its entirety.BACKGROUND[0002]1. Field of the Invention[0003]The present invention relates to an art of a flat heat pipe having a wick structure.[0004]2. Discussion of the Related Art[0005]Heat pipe adapted to transport heat utilizing latent heat of fluid has been widely used as a heat transport device. The conventional heat pipe comprises a tubular sealed container and working fluid encapsulated therein, and both ends of the container are closed. The working fluid is vaporized by a heat of the heat generating element transmitted to one end of the heat pipe, and flows toward the other end to be cooled.[0006]In general, one of the end portions of the heat pipe is brought into contact to the heat generating element to evaporate the working fluid, and the other end portion is b...

AI Technical Summary

Benefits of technology

The technical effect of this patent is to provide a flat heat pipe that can efficiently transport heat with enhanced heat transport capacity. This is achieved by improving the hydrophilicity of the inner face of the container in the evaporating portion, which allows the working fluid to spread smoothly and be evaporated efficiently. This reduces the thermal resistance to heat transport, resulting in improved heat transport performance.

Problems solved by technology

However, since an inner volume of the thin flat heat pipe is rather small, it is difficult to circulate the phase changeable working fluid.

Given that a large wick structure is arranged in the container to enhance capillary pumping to pull the working fluid to a heating site, most part of the internal space would be occupied by the wick structure, and hence it is difficult to ensure the vapor passage sufficiently.

If the working fluid cannot be returned to the heating site sufficiently, the heating site would be dried out.

For example, given that the flat heat pipe is situated horizontally, it would be difficult to return the working fluid to the heating site efficiently by the gravity.

Consequently, heat transport performance of the flat heat pipe will be worsened.

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