摘要
　　本文旨在以實驗量測的方式探討在一單層微米流道熱沉孔上方疊置一毫米流道熱沉形成之雙層流道熱沉孔對比原本單層微米流道熱沉孔所能提升之熱傳效果及壓降增益，並在單層微米流道熱沉孔及雙層流道熱沉孔之下流道內通純水與1%體積濃度之氧化鋁-水奈米流體(上流道固定通純水)，比較不同工作流體對其熱傳及壓降的影響。實驗所製作的雙層流道熱沉孔之上下流道材料皆為無氧銅，在控制上下流道之高寬比相同(皆為2.67)的條件下，上方毫米流道共有8條寬 、高 、長 的流道，其水利直徑為 ；下方微米流道共有24條寬 、高 、長 的流道，其水利直徑為 ，單層微米流道熱沉孔之材料及尺寸皆與雙層流道熱沉孔之下流道相同，並調控單層微米流道熱沉孔之總雷諾數為499.7、995.6及1498.1，換算之總流量為317.02、631.59及950.37 ，將單層微米流道熱沉孔之總流量以不同比例通雙層流道熱沉孔之上下流道，實驗設定之流量比為0.1、0.3、0.6、1、1.1、2、3.7及9，並探討各項物理參數隨流量比的變化。單層微米流道熱沉孔及雙層流道熱沉孔底部皆裝設一加熱模具以模擬等熱通量加熱邊界條件，並控制實驗之入口溫度皆為30℃。實驗結果顯示，於一單層微米流道熱沉孔上方增置一毫米流道熱沉，的確可以大幅降低其所需之壓降，最高之壓降降幅發生於總雷諾數499.7之最高流量比9的情況下，約可降低32倍之壓降，而在熱傳的層面上，最高之熱傳增益發生於總雷諾數995.6之流量比0.3時，約可提升11.7%之熱傳性能。最後，於雙層流道熱沉孔之下流道通1%體積濃度之奈米流體(上流道仍是通純水)來取代純水，實驗結果顯示僅能提升約1.5%之熱傳效果，由於其熱傳提升之幅度在實驗誤差範圍內，因此就誤差分析的角度來看，此熱傳能力的提升不具有任何意義。
關鍵字：雙層流道熱沉孔、單層微米流道熱沉孔、奈米流體

SUMMARY
This paper aims to investigate the double-layer heat sink formed by stacking a millimeter flow channel heat sink over a single-layer micro-channel heat sink in an experimental measurement manner compared with the original single-layer micro-channel heat sink. And adopt the pure water and the 1% volume of alumina-water nanofluid in the single-layer micro-channel and under layer of the double-layer heat sink (the upper layer fixed to the pure water) to compare the effect of fluid on its heat transfer and pressure drop.The experimental results show that the addition of a millimeter heat sink above a single-layer micro-channel heat sink can significantly reduce the required pressure drop. The highest pressure drop occurs at the highest flow ratio 9 of 499.7 total Reynolds number. In this case, the pressure drop can be reduced by about 32 times, and at the heat transfer performance, the highest heat transfer occurs at the flow rate 0.3 of the total Reynolds number of 995.6 , which can improve the heat transfer performance by about 11.7%. Finally, the under layer of the double-layer heat sink is replaced by 1% volume concentration of nanofluid (the upper channel is still pure water), and the experimental results show that only about 1.5% of the heat transfer effect can be improved.
Key words: double-layer heat sink, single-layer heat sink, Nanofluids

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