Multi-scale capillary core flat plate loop heat pipe type heat-dissipation device

Abstract

The invention relates to a multi-scale capillary core flat plate loop heat pipe type heat-dissipation device, and belongs to the technical field of phase transition heat dissipation. The heat-dissipation device comprises an evaporating part, a condensing part, a compensating cavity, a gas phase pipeline and a liquid phase pipeline, wherein the gas phase pipeline is connected with the evaporating part and the condensing part, and the liquid phase pipeline is connected with the condensing part and the compensating cavity; a base plate of the evaporating part is in a flat plate shape, metal powder is sintered to form two layers of multi-scale capillary cores at the upper surface of the base plate, and a steam channel is constructed between the two layers of capillary cores; a layer of water absorption cotton tightly covers a second layer of capillary cores and is taken as a third layer of capillary cores, and the three layers of capillary cores form a multi-scale structure. By utilizing the multiple layers of multi-scale capillary cores and the constructed steam channel, the problem of the contradictoriness between the vapor-liquid flow resistance and the capillary suction force is solved, the starting temperature of a loop heat pipe is lowered, the high heating flux bearing capacity of the heat-dissipation device is improved, and the instability in heat transfer is reduced; the multi-scale capillary core flat plate loop heat pipe type heat-dissipation device has the advantages of high cooling capacity, large heat flux bearing capacity, low starting temperature, small temperature fluctuation, good antigravity performance and long transmission distance.

Description

technical field [0001] The invention relates to a multi-scale capillary core flat plate loop heat pipe type cooling device, which belongs to the technical field of phase change heat dissipation and can be used for cooling high heat flux density electronic and optical devices. Background technique [0002] With the development of science and technology, the miniaturization and high integration of high-power lasers, high-power LEDs, infrared detection arrays, high-power and high-performance microprocessors and other optoelectronic / microelectronic chips (referred to as "optoelectronic chips") and their application systems As a result, the calorific value per unit volume increases sharply, and the local heat flux density is relatively large. The traditional heat dissipation method that simply uses air forced convection cooling has reached its heat transfer limit. The problem of heat dissipation has become a constraint for high heat flux photoelectric chips. The main bottleneck o...

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Problems solved by technology

[0005] In terms of the internal structure design of the evaporating part, traditional loop heat pipes usually use mechanical processing to cut out different forms of steam channels on the bottom surface of the evaporating part and cover them with a layer of capillary core, although this structure is easy to manufacture , but such a design faces an unsolvable contradiction. On the one hand, it is hoped to obtain a wider channel to reduce the pressure loss when the steam is discharged, and a larger capillary pore to reduce the resistance of vapor-liquid flow. On the other hand, it is hoped to obtain a larger Large capillary suction to increase the power of working fluid circulation, which requires smaller capillary core pores, but limited by the size of the space, the two cannot be balanced (for loop heat pipes, the large pores of the capillary core have a great impact on the vapor-liquid The flow resistance is small, which is conducive to the circulation of vapor and liquid, but the capillary suction is small, and the small pores have greater capillary suction, which can provide greater power for vapor-liquid circulation. The two are a contradictory unity. The traditional loop heat pipe The capillary core is not able to coordinate this contradiction well

Therefore, the traditional loop heat pipe often has the problems of difficulty in starting at low temperature, large temperature fluctuations, and low ultimate heat dissipation capacity.

[0006] In addition, the traditional loop heat pipe often has the problem of heat leakage from the evaporation chamber to the compensation chamber due to the design of the capillary core.

On the one hand, the heat conduction of the capillary causes the temperature in the compensation chamber to be too high; on the other hand, the steam in the evaporation chamber will enter the compensation chamber through the capillary, both of which will cause difficulty in starting the loop heat pipe, and even in some cases At the same time, when working in reverse (that is, the evaporating part is on the top and the condensing part is on the bottom, the liquid mainly exists in the pipeline due to gravity, and there is less liquid in the compensation chamber, so that the steam generated when the loop heat pipe starts The pressure is difficult to overcome the circulation resistance, resulting in failure to start

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