A powder-microfiber composite porous capillary core for loop heat pipe system

Abstract

The invention discloses a powder-microfiber composite porous capillary core applicable to a loop heat pipe system and belongs to the technical field of porous medium phase change heat transmission and flow. The capillary core adopts metal powder and microfiber for mixing and sintering, and the metal powder is connected through the microfiber, so that a double-aperture porous medium structure is realized, wherein the double apertures comprise a small aperture formed by microfiber among powder and a large aperture formed between particles and powder. The unique structure of the capillary core enables the capillary core to have the flow heat transmission properties of high capillary suction force, low flow resistance, high surface evaporativity and low effective heat conductivity. When the powder-microfiber composite porous capillary core is applied to the loop heat pipe system, the internal heat transmission medium can be intensified, the evaporation phase-change interface of a working medium can be stabilized, heat leakage to a compensation cavity can be reduced, the temperature fluctuation of system operation can be eliminated or weakened so as to improve the operating property of a loop heat pipe.

Description

technical field [0001] The invention belongs to the field of porous medium phase change heat transfer and flow technology, and specifically relates to a powder-microfiber composite porous capillary core applied to a loop heat pipe system, which can be applied to heat dissipation of portable or desktop computers and other high heat flux electronic devices, etc. field. Background technique [0002] The loop heat pipe is a high-efficiency passive heat transfer device that uses the phase change of the working fluid to transfer heat. It has the advantages of strong heat transfer capacity, low heat transfer resistance, long transmission distance, good isothermal performance, and no moving parts. It is suitable for high heat flow Heat dissipation of high-density electronic devices and thermal control of spacecraft. The loop heat pipe is a separated heat pipe, which is mainly composed of an evaporator, a condenser, a steam pipe, a liquid pipe and a compensation chamber. The evapor...

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Problems solved by technology

The temperature rise of the compensation chamber leads to a phase change of the liquid in the compensation chamber. The compensation chamber is in a gas-liquid two-phase state, and the internal pressure increases, which increases the resistance of the system operation, thus increasing the operating temperature of the system.

With the increase of operating heat load, the evaporation phase change interface in the capillary core migrates to the inside, which is not conducive to the detachment of generated steam, and may increase the temperature fluctuation of system operation

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