flat heat pipe

Abstract

The invention relates to a flat heat pipe, which comprises a sealed shell, a cavity which is formed in the shell and working media which are filled in the cavity. The flat heat pipe is provided with an evaporation section and a condensation section. A first capillary structure and a second capillary structure are attached onto the inner wall of the shell. The first capillary structure is of a silk-screen-type capillary structure, is cylindrical and extends to the condensation section from the evaporation section. A hole is formed in the first capillary structure at a position corresponding to the bottom end of the evaporation section of the flat heat pipe. The second capillary structure is arranged at the position of the hole and is connected with the first capillary structure. The second capillary structure is of a sintered type. The diameter of the capillary pores of the second capillary structure is smaller than the diameter of the capillary pores of the first capillary structure. The second capillary structure is attached onto the inner wall of the shell through the hole in the first capillary structure. Not only can the flat heat pipe have smaller liquid backflow resistance and larger capillary acting force, and can the capillary acting force of the flat heat pipe at a position close to a heat source be improved, but also the cavity in the flat heat pipe can be enabled to have a larger space.

Description

technical field [0001] The invention relates to a heat transfer device, in particular to a flat heat pipe. Background technique [0002] Heat pipes are widely used due to their characteristics of ultra-quiet, high thermal conductivity, light weight, small size, simple structure and multi-purpose. The space is in the state of a hollow body, and the working fluid is injected into the vacuumed airtight pipe. The heat pipe is divided into an evaporation section and a condensation section according to the relative position of heat absorption and dissipation; its working principle is to transfer heat through the vapor-liquid two-phase change of the working liquid. First, the working liquid absorbs the heat from the heat source in the evaporating section, evaporates the working liquid and makes the steam quickly pass through the space in the tube, and reaches the condensing section to cool and condense into a liquid and release heat energy. The working liquid in the condensing sec...

AI Technical Summary

Problems solved by technology

[0003] At present, the capillary structure in the heat pipe is usually a single capillary structure, and the return channel of the condensed liquid in the condensation section of the heat pipe with a single capillary structure uses the same capillary structure at the position of the heat source in the evaporation section to make each part of the heat pipe work The maximum heat flux density that can be tolerated locally is almost the same, and it is impossible to have a small liquid return resistance and a large capillary force at the same time

For this reason, the industry adopts a multi-layer composite capillary structure to enhance the capillary force, and this setting will reduce the flow space of the gaseous working medium in the inner cavity of the heat pipe, especially when the heat pipe is flattened to a thinner thickness , will affect its thermal conductivity

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