歧管式射流微通道液冷散热性能

Performance of manifold microchannel liquid cooling

随着信息技术进步,芯片向大面积、高功率方向发展,对热管理提出了严峻挑战。微通道液冷能够解决高功率芯片散热难题,但传统平直微通道热沉流阻大、温度均匀性差。提出了一种耦合歧管式进出液结构、分布式射流和微针翅的新型歧管式微通道散热器,在平均热通量高于330 W/cm^(2)、总功率达到2500 W时,芯片平均温度低于70℃,实现了高效散热。通过数值模拟发现:降低散热器射流腔高度可显著强化传热,但整体压降也随之陡升,存在一个最佳射流腔高度;散热器底板的微针翅尺寸及其与射流腔的相对尺寸是新型歧管式微通道散热器的重要结构参数,微针翅的存在并不是绝对有益于传热强化。定义了微针翅与射流腔之间相对高度的无量纲参数——翅占比,存在临界翅占比使得阻碍效应和强化效应相抵消,当翅占比高于这一临界值时才能达到强化换热效果。本研究为新型歧管式微通道散热器的设计提供了指导。

As advancements in information technology progress,chip development is moving towards large-area,high-power configurations,posing significant challenges in heat management.Microchannel liquid cooling has emerged as a viable solution to address the thermal management difficulties associated with high-power chips.Microchannel liquid cooling has emerged as a solution to address the thermal management difficulties associated with high-power chips.However,traditional straight microchannels suffer from high flow resistance and poor temperature uniformity.This paper introduces a novel manifold microchannel heat sink by incorporating a manifold inlet/outlet liquid structure,distributed jet impingement,and micro-pin fins.Under conditions where the average heat flux density exceeds 330 W/cm^(2)and the total power reaches 2500 W,the chip’s average temperature remains below 70℃,indicating that high efficiency cooling is achieved.Through numerical simulation,it is found that increasing the height of the jet impingement chamber leads to a significantly increase in heat transfer coefficient,albeit at the expense of an obvious increase in overall pressure drop.An optimum height of the jet impingement chamber is thereby identified.The dimensions of the micro-pin fins on the base plate,along with their relative proportions to the size of jet impingement chamber,emerge as critical structural parameters for the proposed microchannel heat sink.The presence of micro-pin fins does not uniformly contribute to heat transfer enhancement.A dimensionless parameter,micro-pin fin ratio,is introduced to signify the relative height between the micro-pin fins and the jet impingement chamber.A critical micro-pin fin ratio is realized by balancing the obstructing and enhancing effects.When the proportion of fins is higher than this critical value,the effect of enhanced heat transfer can be achieved.This study provides valuable guidance for the systematic design of the novel microchannel heat sink.