Composite liquid absorption core for loop heat pipe

Abstract

The invention discloses a composite liquid absorption core for a loop heat pipe. The composite liquid absorption core for the loop heat pipe is composed of metal powder, small phase-change balls and holes, wherein the diameter of the metal powder is 25-150 micrometers; each small phase-change ball is composed of a small phase-change ball outer shell and phase-change materials in the outer shell, the diameter of the small phase-change balls is 1-3 mm, and the solid-liquid phase-change temperature of the phase-change materials is 3 DEG C lower than the boiling point of work medium in the loop heat pipe; the size of the holes is realized by controlling the proportion of the metal powder with different particle diameters and the small phase-change balls. The composite liquid absorption core for the loop heat pipe can effectively avoid starting failure of the loop heat pipe caused by heat leakage of an evaporator shell body and the backward heat conduction effect of the liquid absorption core in the initial starting period of the loop heat pipe, facilitates smooth starting of the loop heat pipe and improves the operation stability of the loop heat pipe.

Description

technical field [0001] The invention relates to the technical field of thermal energy engineering, and more specifically relates to a composite liquid-absorbing core for a loop heat pipe. Background technique [0002] Loop heat pipes are widely used in the cooling and heat dissipation of high heat flux density devices in the fields of aerospace, high-power LEDs, and large servers. The loop heat pipe is a closed two-phase circulation heat transfer device that is driven by capillary suction and uses phase change for heat transfer. The evaporator and condenser of the loop heat pipe are two relatively separated parts, so the positions of the evaporator and condenser can be flexibly arranged according to the actual application, and a circuit is formed through a steam connection pipe and a liquid connection pipe. However, there are many deficiencies in the loop heat pipe itself, which are mainly manifested in two aspects: on the one hand, the heat conduction of the side wall and ...

AI Technical Summary

Problems solved by technology

However, there are many deficiencies in the loop heat pipe itself, which are mainly manifested in two aspects: on the one hand, the heat conduction of the side wall and the heat leakage of the wick, and on the other hand, the return resistance of the wick and the capillary pressure head cannot be balanced.

First, part of the heat from the bottom plate will be transferred to the liquid-absorbing core and the compensation chamber through the side wall, and another part of the heat will leak to the compensation chamber through the liquid-absorbing core. The above-mentioned harmful heat transfer is mainly caused by the inherent structure of the loop heat pipe evaporator , will lead to a phase change in the liquid-absorbing core and the circulating working fluid inside the compensation chamber, so the compensation chamber and the evaporation chamber cannot establish the pressure difference required for circulation, which will easily lead to the failure of the loop heat pipe to start

In addition, due to the single particle size of the traditional liquid-absorbent core, the liquid-absorbent core cannot take into account the large capillary pressure head and the small return resistance at the same time, although composite liquid-absorbent cores with different particle sizes have appeared in the field of theoretical research , but the complex process and manufacturing cost limit the further application of the loop heat pipe

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