本實驗主要研究為使用於液體冷卻系統中的微熱交換器，將已知的熱傳增強技術作為流道結構設計。主要參考工業界廣泛使用的山型紋板式熱交換器，利用山型紋來增加流體擾動，以及常用於氣體冷卻之斷續型鰭片，破壞流道內邊界層的成長，利用相同的熱傳增強原理，作為流道結構設計，以提升熱傳性能。而為了降低微熱交換器的壓降，首先更改入出口型式，減少入出口造成的壓降。對於山型紋所造成的壓降，則是製作多層板片的山型紋微熱交換器。各式微熱交換器之壓降與熱傳性能，經由實驗測試皆已了解並討論。 在相同的泵動力下，熱阻由低至高依序為：山型紋30度三層、山型紋30度、翼型斷續型鰭片與山型紋30度四層。山型紋型式，在加熱量100瓦時，仍可以維持中心點溫度在70 oC以下。在相同流量下，山型紋30度的壓降最高，而多層山型紋能有效降低壓降，並且熱傳性能不置於降低太多。斷續型鰭片能與山型紋有相近的熱阻，並且不需製作多層板片，即可降低壓降。各式微熱交換器間具有不同的熱傳與壓降特性，可以根據能提供的泵動力大小以及溫度限制，來選擇適用的型式。 This paper describes a micro heat exchanger of a liquid cooling system. The single-phase heat transfer enhancement techniques are well established for micro heat exchangers. The major techniques include breakup of boundary layer, secondary flow and mixers. There are some methods to decrease pressure drop penalty. First, the inlet and outlet of exchanger. Second, the multilayer exchanger for chevron. The pressure drop and heat transfer characteristics of micro heat exchanger were investigated experimentally. The experimental results show that at the same pumping power. The thermal resistance of the Chevron30x3 is less than that Chevron30, OSF-Airfoil and Chevron30x4. And the chevron type of exchanger that can keep the maximum temperature below 70 oC. At the same flow rate, the pressure drop of the multilayer exchanger are less than that of the single-layer case, besides the OSF-Airfoil. Every kinds of micro heat exchanger have different performance of the pressure drop and heat transfer. We can choose exchangers that we need by the performance of pumping power and limited of the maximum temperature.
