液冷式多孔流道散熱器之熱流分析

Thermal and Flow Analysis on Liquid Heat Sink with Porous Channel

洪淑鴻(Shu-Hong Hong)

指導教授 ： 王阿成

共同指導教授 ： 梁國柱

健行科技大學/工學院/機械工程所/碩士(2009年)

摘要

目前市面上液冷式散熱器多為一體成型的散熱鰭片，而並不是一昧的增加鰭片厚度就能使散熱器達到良好的效能。所以本研究目的在設計一個整體性能佳的液冷式多孔流道散熱器，利用多孔性的概念，結合層疊式的散熱片，增加散熱面積並提高散熱效率，透過計算流體力學(Computational Fluid Dynamics，CFD)軟體並配合田口法(Taguchi method)作模擬規劃，由田口法實驗計畫結果分析出各散熱器模型對於散熱效果的影響控制因子與水準數對溫度的影響。探討不同水流量、鰭片寬度、鰭片流道寬度、鰭片厚度等影響最佳化散熱器尺寸之散熱效果。最後並將實驗與數值模擬結果做比對與驗證。
由研究結果得到，在60W功率、0.9LPM流量作用下，最佳化散熱器之熱阻值可達0.053℃/W，與一般鰭片型散熱器在同功率為60W時，熱阻值則為0.086℃/W，於整體評估下，本研究所設計的散熱器具有良好的冷卻性能。而液冷式散熱器在功率90W、不同流量時，數值模擬與實驗結果之比較，結果顯示數值模擬與實驗間的誤差值最高僅5.4％。而在實驗中發現，本文所設計之液冷式散熱器效能比市售水冷散熱器高13%，達到了本研究的設計目的在有限的空間內，促使液冷式散熱器得到良好的散熱性能。

關鍵字

田口方法 ； 熱阻值 ； 多孔性 ； 液冷式散熱器

並列摘要

Liquid heat sinks markedly dissipate heat from CPU with small heat exchanger. However, temperature gradients are still large without enough heat convection in liquid heat sinks. Therefore, a novel liquid heat sink with porosity was designed to locate the low temperature gradients. A rib with many horizontal fins was designed in a plate to become the base of the dissipated fin; then stacked two or more of them with each angle 180o to change as porous fins of heat sink. Next, using CFD software to simulate the performance of liquid heat sink model and combining Taguchi method to obtain the optimal parameters of the liquid heat sink. Additionally, optimal liquid heat sink could be set-up during Taguchi results. Finally, experiment results of liquid heat sink with porosity would be compared with general liquid heat sink to find the different performance of these heat sinks.
Observations showed that liquid heat sink with porosity performed better than liquid heat sink with long flow channel and temperature of liquid heat sink reduced to 28.4oC when only stacked two layers of the porous fins in the dissipated system. Taguchi results demonstrated that liquid flow rate, layers of porous fin and thickness of porous fin were the important factors affecting the performance of liquid heat sink. This heat sink performed excellent thermal resistance to 0.053℃/W at source power 60 watt and liquid flow rate 0.9 LPM. The error between simulated result and experimental result was only 5.4%, meaning this liquid heat sink create excellent performance in heat dissipated process.

並列關鍵字

Taguchi method ； thermal resistance ； porous ； liquid cooling heat sink

參考文獻

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