臺灣博碩士論文加值系統

傳統個人電腦系統主機熱對流分析對策在電腦業界已有多年研究發展，各式各樣的CPU散熱器令人眼花撩亂，在材質上有純鋁、純銅等，製程上則有擠製加工、刨折加工、衝壓、錫銲等，現在也運用了熱導管技術解決CPU高運算時脈的散熱對策。
對於機殼內部空間非常有限的Mini PC，市面上大部分的CPU散熱器由於體積太大，無法置入機殼中；少部分高度較低的散熱器安裝後，經實測卻發現晶片溫度太高，與散熱器廠商提供的熱阻資料相差太多。另外一個現象是幾乎所有市售的散熱器風扇都是正向對著CPU吹，因為Mini PC機殼內部空間非常有限，無法安裝系統風扇，造成系統內部廢熱無法有效排出。
在本論文中主要是針對Mini PC整體系統的散熱問題作探討，研究方法為利用模擬軟體Icepak來分析不同的散熱器及風扇配置對整體系統的速度場、壓力場及溫度場的影響，並且以實機系統測試的結果與模擬結果相互驗證，藉以分析不同的設計參數對系統散熱性能的影響。本文在後段提出三組改善方案進行模擬，其改善方案(參數)如下：
方案A(外殼開孔率0.75) 數值模擬結果分析
方案B(使用銅底銅鰭片) 數值模擬結果分析
方案C(主機板底部加鋁板) 數值模擬結果分析

利用熱流模擬分析軟體可使熱流設計者在無實際樣機前的設計推論中，有效掌握系統熱場及流場分布的趨勢，減少嘗試錯誤的次數，使設計作業開發期縮短，降低成本並且提高競爭力。而本研究的目的，期望由電腦模擬設計出散熱效果較好的組合，以提供相關廠商對Mini PC整體系統散熱設計開發的參考。

Various thermal solutions for the cooling of traditional personal computers have been in practice for many years and valuable experiences have been accumulated. Every kind of CPU cooler dazzles the eyes. The primary materials used for cooling purpose include Al and Cu, the producing processes include extrusion, dig, punch, solder and so on. The use of heat-pipe technology has been very popular recently since it can solve systems with high thermal cooling demand.
We try to employ the coolers from various vendors and find most coolers can not fit properly inside our mini system well because most coolers are too big for the limited space of Mini PC. A few coolers with lower height can be put inside the mini system but the cooling effect is bad after thermal test and their heat resistances are different with specs provided by their vendors.
The purpose of this study is to analyze the cooling performance of a Mini PC system using numerical and experimental methods. The research investigate the cooling performance of four kinds of cooler experimentally and compare the thermal test results with the simulation results obtained from commercial CFD code, ICEPAK.
Finally three different strategies to improve the thermal performance are proposed and compared by using the CFD code.

中文摘要…………………………………………………….….………Ⅰ
英文摘要…………………………………………………….….………Ⅲ
誌謝……………………………………………………………………..Ⅳ
目錄……………………………………………………………………..Ⅴ
圖目錄…………………………………………………………………..Ⅸ
表目錄………………………………………………………………..ⅩⅣ符號說明………………………………..……………………………ⅩⅤ
第一章 緒論……………………………………………………………1
1.1 前言……………………..……………………………………...1
1.2 Mini-PC的發展背景……………...………….....……..………2
1.3 研究動機與方法………..……………………………………...3
第二章 Mini-PC系統熱傳分析…………………………………….…5
2.1 文獻回顧….………………………...……….…...…..………...5
2.2 Mini-PC系統介紹….……………………………......……….13
2.3 熱傳分析…………………………………………......……….15
2.3.1 系統熱網路模型…………………….………….……15
2.3.2 熱傳導………….………………………..……...……19
2.3.3 熱對流…………….……………………..……...……22
第三章 實驗規劃與測試結果…………………………..……………25
3.1 待測物簡介…….….…………………………..………….…26
3.2 測試設備簡介……………………………….………………28
3.3 實驗與模擬規劃說明………………………….……………35
3.3.1 系統測試條件說明…………………………………36
3.3.2 系統測試點規劃……………………………………37
3.3.3 CPU散熱器測試說明…………………..……….….44
3.3.4 風扇特性曲線…………………………..…………..50
3.4 實驗測試結果……………………………………………….52
3.4.1 TEST(1) 正吹式散熱器實測結果分析……….....…..53
3.4.2 TEST(2) 後吸式散熱器實測結果分析...…….….......54
3.4.3 TEST(3) 側吹式散熱器實測結果分析...……………55
3.4.4 TEST(4) 低轉速側吹式散熱器實測結果分析...……56
3.4.5 四組散熱器實測結果比較分析...……………….......57
3.4.6 TEST(5) 不同風扇噪音量測結果……………...……58
第四章 數值模擬與分析……………………………………………..65
4.1 模擬分析軟體 Fluent Icepak 簡介……………………..….65
4.2 模擬分析步驟………………………………………..…..….67
4.3 模擬分析理論基礎…………………….…….………..….…68
4.3.1 統御方程式………………………………..………..68
4.3.2 有限體積法………………………………..………..69
4.3.3 交錯式網格系統……………………………..……..70
4.4 系統數值模型建立………………..……..……………….…73
4.4.1 系統模型建立說明…………………………..……..73
4.4.2 模型建立……………………………………..……..74
4.5 系統模擬…………………...……………………….…..…...79
4.5.1 數值模擬系統參數設定…………………..…..……79
4.5.2 網格測試…………………………………..………..80
第五章 實測與模擬比對討論及修正參數研究分析…….…….……82
5.1 說明……………………………………………….…………82
5.2 實驗量測與數值模擬對照……….……………………..…..83
5.2.1 TEST(1) 正吹式散熱器實測與模擬結果分析…...…83
5.2.2 TEST(2) 後吸式散熱器實測與模擬結果分析...…....87
5.2.3 TEST(3) 側吹式散熱器實測與模擬結果分析...…....91
5.2.4 TEST(4) 低轉速側吹式散熱器實測與模擬結果分析………………………………………………………..……..95
5.3 修改系統散熱參數與數值模擬…………………………...99
5.3.1 方案A(外殼開孔率0.75)數值模擬結果分析……….99
5.3.2 方案B(使用銅底銅鰭片)數值模擬結果分析..…….102
5.3.3 方案C(主機板底部增加鋁板)數值模擬結果分析...105
5.3.4 三組改善方案分析比較……………………………109
5.3.5 同時使用三組改善方案模擬結果…………………111
第六章 結論與建議……..…………………………………………..113
6.1 結論…………………………………………………….…113
6.2 建議………………………………………………….……115
參考文獻…………………………………………..…………………..116
作者簡介………………………………………………………………1

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