关键词: 超薄平板热管, 改性, 充液率, 传热性能, 传热

Abstract:

The development of high-performance electronic devices requires heat transfer devices with thinner thickness and higher heat transfer performance. Heat pipe relies on the latent heat of internal working medium phase change to transfer heat. It has the characteristics of high thermal conductivity and good temperature equalization effect. It is widely used in the heat dissipation of electronic devices. In this paper, an ultra-thin flat plate heat pipe with a thickness of 0.6mm was fabricated. The interior of the heat pipe shell and the copper wire mesh were hydrophilic modified. The steam channel was processed by the wire mesh to realize gas-liquid coplanar to reduce the flow resistance. A heat pipe performance test platform was built to study the effects of deionized water and ethanol and different liquid filling rates on the heat transfer performance of ultra-thin flat heat pipe under the condition of natural convection cooling. The results showed that the chemical modification improved the wettability of the shell and copper wire mesh to deionized water, and improved the capillary force of the copper wire mesh at the same time, after hydrophilic modification, the thermal conductivity of deionized water heat pipe increased by 19.53% compared with that before modification. The optimum liquid filling rate of the heat pipe filled with the two working fluids was 1.0, and the maximum power allowed to be input was 6W when the maximum temperature of the evaporation section was controlled to be less than 80℃. The heat pipe filled with deionized water showed better thermal performance.

Key words: ultra thin flat heat pipe, modification, liquid filling rate, thermal performance, heat transfer