雙孔徑毛細結構於迴路式熱管之熱傳增強研究

Heat Transport Capacity Enhancement of the Biporous Wick for Loop Heat Pipes

林修緯(Hsiu-Wei Lin)

指導教授 ： 陳瑤明

國立臺灣大學/工學院/機械工程學研究所/碩士(2006年)

https://doi.org/10.6342/NTU.2006.02699

摘要

迴路式熱管是一種利用相變化散熱的散熱元件，擁有熱傳輸距離長、熱阻小、熱傳量大等優勢，為了應用於電子產品散熱，必須將迴路式熱管小型化，並藉由高性能的毛細結構來提升熱傳性能。故本實驗將研究迴路式熱管的主要元件-毛細結構，其中雙孔徑毛細結構是相當有研究價值的一項，而其同時擁有大孔徑以及小孔徑的孔徑分佈，將可提升熱傳性能。
本實驗中利用添加孔洞成型劑的方式來製造雙孔徑毛細結構，並控制孔洞成型劑的粒徑(改變大孔孔徑)、添加量(改變大小孔含量比例)以及燒結溫度(改變小孔孔徑)，以調控雙孔徑毛細結構的孔徑分佈，並以2-Level實驗設計進行，結果顯示當孔洞成型劑粉末粒徑較小、含量較多並且燒結溫度較高時，擁有較佳的熱傳性能，其中孔洞成型劑的含量為影響熱傳性能的關鍵。
成功製造出雙孔徑毛細結構，孔洞成型劑添加量30%、孔洞成型劑粉末粒徑為74~88μm、燒結溫度為750℃，其滲透度為1.034×10-11m2，孔隙度為83.1%，將其置入迴路式熱管進行熱傳性能測試，在熱沉10℃時，單孔徑毛細結構熱傳量為100W，熱阻為0.553 ℃/W，而雙孔徑毛細結構熱傳量可達400W以上，熱阻為0.297℃/W。

關鍵字

迴路式熱管 ； 雙孔徑毛細結構 ； 孔徑分佈

並列摘要

Loop heat pipe (LHP) which is one of the phase-changing cooling devices could achieve long transport distance, low thermal resistance and high heat transfer. Recently, LHP was miniaturized and its performance was enhanced by improved the wick structure for electronic cooling. The main purpose of this study is to enhance the performance of miniature LHPs by using the bi-porous wick structures, which incorporates the advantages of different pore size distributions.
In the experiments, nickel powders were mixed with the pore former (Na2CO3) to generate the bi-porous wick. To control the pore size distributions, the amount and particle size of pore formers, and the sintering temperature were investigated. Moreover, a two-level experiment-design was made to determine the optimized parameter combination of the bi-porous wick. The results showed that, smaller size and larger amount pore former, and higher sintering temperature would lead to better performance of the bi-porous wick. Among the various parameters, the amount of pore former is the key factor.
The wick parameters of manufactured bi-porous wick, with the pore former content of 40%, the particle size of pore former of 74~88μm and the sintering temperature of 750℃ was measured. The permeability and porosity were found to be 1.034×10-11m2 and 83.1% respectively. The performance test under the heat sink temperature of 10℃ revealed that the heat transfer capacity of mono-porous LHP system was 100W and the thermal resistance was 0.553℃/W, While the bi-porous LHP achieved the maximum heat transport capability of 400W, and the thermal resistance was 0.297℃/W.

並列關鍵字

loop heat pipe ； biporous wick structure ； pore distribution

參考文獻

王鵬凱，“應用於迴路式熱管高分子毛細結構之製造研究”，國立台灣大學碩士論文，2004.

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