臺灣博碩士論文加值系統

本研究以實驗方法探討應用於LED散熱之環型與鰭片型金屬發泡散熱座之自然對流熱傳特性，散熱座的本體為直徑76mm、高度14.6mm、厚度3mm之具／不具徑向幅射排列鰭片之鋁合金圓環杯狀物，環型金屬發泡散熱座是在不具鰭片之本體外部包覆0.97孔隙率的環形發泡銅材，鰭片型金屬發泡散熱座則是在具鰭片之本體其鰭片兩側貼附0.97孔隙率的片狀發泡銅材。本研究之變動參數包括：加熱面與環境之間的溫差(ΔT=30~60℃)、發泡銅材之孔密度(PPI=20、30與40)、環型發泡銅材厚度(tc=5、11與14.5mm)、鰭片數目(n=7、8與9)、鰭片長度(t=5與11mm)與鰭片型發泡銅材厚度(s=5、8與11mm)，實驗結果發現在環型金屬發泡散熱座時，當tc=5 mm時，熱傳係數(h)會隨著PPI的增大而下降，然而，當tc=11與14.5 mm時，熱傳係數(h)卻會隨著PPI的增大而上升，PPI效應之反轉變化約發生在tc=6.5~7.5 mm之間；在鰭片型金屬發泡散熱座時，當s=5mm時，PPI的變化對熱傳增益變化不大，然而，隨著s上升，熱傳係數(h)也會隨著PPI的增大而上升；在目前所有測試例中，以40PPI、n=9、t=11mm、s=11mm的鰭片型金屬發泡散熱座有最佳的自然對流熱傳能力。

This study experimentally investigated the free convective heat transfer characteristics of annular and fin shaped metal foam heat sinks applied to the cooling of LEDs. The basic body of the heat sink made of aluminum alloy was an annular cup with/without radially fins, and had 76 mm in diameter, 14.6mm in height and 3mm in thickness. The annular metal foam heat sink was to cover the annular 0.97-porosity copper foam layer onto the external surface of the annular cup; while the fin shaped metal foam heat sink was to attach the 0.97-porosity cooper foam plates at both sides of each fin of the finned annular cup. The variable parameters were the difference of the temperatures between the heated surface and the environment (ΔT=30~60℃), the pore density of the copper foam material (PPI=20, 30 and 40), the thickness of the annular foam layer (tc=5, 11 and 14.5mm), the fin number (n=7, 8 and 9), the fin length (t=5 and 11mm), and the thickness of the copper foam plates attached onto the fins (s=5, 8 and 11mm). The experimental results indicate that, for annular metal foam heat sinks with tc=5mm, the heat transfer coefficient (h) would drop with increase of PPI. However, the heat transfer coefficient (h) would rise with increase of PPI as tc=11 and 14.5mm. The PPI effect showed reverse about at tc=6.5~7.5mm. For the fin shaped metal foam heat sinks with s=5mm, the effect of PPI on the heat transfer was insignificant. In addition, as the rise of the s, the heat transfer coefficient (h) wound be elevated with increase of the PPI. Among the current test cases, the fin shaped metal foam heat sink with 40PPI, n=9, t=11mm and s=11mm has the maximum free convective heat transfer capacity.

目 錄 頁次
中文摘要········································ Ⅰ
英文摘要········································ Ⅱ
誌謝 ·········································· Ⅲ
目錄 ·········································· Ⅳ
表目錄········································· Ⅵ
圖目錄········································· Ⅶ
符號說明········································Ⅸ
第一章緒論 ·····································01
1-1研究背景·····································01
1-2LED金屬多孔性介質散熱座之自然對流熱傳機制·······12
1-3文獻回顧·····································15
1-3-1LED燈之散熱設計文獻·························15
1-3-2鰭片散熱座之熱傳文獻························16
1-3-3金屬多孔性介質於自然對流之熱傳文獻···········18
1-3-4金屬多孔性介質於非自然對流之熱傳文獻··········20
1-4 研究目標··································· 21
1-5 研究架構··································· 23
第二章實驗方法·································· 24
2-1熱傳實驗設備及流程··························· 24
2-1-1實驗測試段································ 24
2-1-2實驗測試塊································ 26
2-1-3熱量供應系統······························ 27
2-1-4資料擷取系統······························ 27
2-1-5熱影像系統································ 28
2-2 實驗流程··································· 29
2-3 數據整理··································· 31
2-3-1第一加熱模式數據整理方式(無金屬發泡材構型) ··· 31
2-3-2第二加熱模式數據整理方式(無金屬發泡材構型) ··· 33
2-3-3第一加熱模式數據整理方式(有金屬發泡材構型) ··· 35
2-4 不確定度分析································ 37
2-5 實驗測試例·································· 40
第三章結果與討論································· 53
3-1 環型散熱座之熱傳分析························· 53
3-2 鰭片型多孔性散熱座之熱傳分析·················· 58
第四章結論與未來展望····························· 72
4-1 重要結論···································· 72
4-2 未來展望···································· 74
參考文獻········································ 75
附錄 A電木物理性能表-複合斷熱材料特性·············· 78
附錄 B實驗設備一覽表····························· 79
附錄 C作者簡歷·································· 81

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