影響熱管最大熱傳量之參數設計與分析

The Design Parameter for the Maximum Heat Transfer Analysis on the Miniature Heat Pipe

盧俊彰(Chun-Chang Lu)

指導教授 ： 林唯耕

國立清華大學/原子科學院/工程與系統科學系/博士(2009年)

摘要

熱管的傳輸機制，可以快速進行雙相熱傳於熱通量從10 W/cm2至20 KW/cm2。因此，熱管被廣泛應用於1U伺服器、筆記本電腦與個人電腦等產品。熱管是一種移熱裝置，是一個被抽以真空之金屬管，裡面填充定量之的工作流體並加以密封。因此，熱管的性能不僅取決於幾何參數，如壁厚，管材料，以及工作流體之熱力性能，如潛熱，蒸汽壓力，粘度，壓力和真空。
本文不僅提出了一個理論模型，為熱管預測的最大熱傳量，而且還求出了最大熱傳量對於不同長度的蒸發器和冷凝器的影響、不同的工作溫度和不同真空度對熱管對最大熱傳量也表明在本研究中。這些數據將以實驗和模擬做基準比較並得到一理想結果。從實驗中顯示，最大熱傳量會隨著熱管直徑和操作溫度上升而增加。最大熱傳量在模擬和實驗上之偏差值均小於15 ％ 。這意味著，此最大熱傳量模型是有利於設計熱管性能的能力之工具。且本研究針對真空度量測進行討論，並提出一真空量測理論，藉以破壞量測已成型之熱管初始真空量。實驗顯示，其量測與實際真空度相當接近，且具有重現係之可信度。

關鍵字

熱管 ； 真空壓力 ； 最大熱傳量 ； 滲透度 ； 非凝結氣體

並列摘要

Heat pipes are transport mechanisms that can carry heat fluxes ranging from 10 W/cm2 to 20 KW/cm2 at extremely fast speeds. Therefore, heat pipes are widely used in 1U servers, notebooks, PCs, etc. A heat pipe is a heat removal device comprising a vacuum pipe that charges a certain amount of working fluid and seals the tube. Hence, the heat pipe performance depends not only on the geometric parameters such as wall thickness, tube material, and wick material but also on the thermal properties of the working fluid such as latent heat, vapor pressure, viscosity, and vacuum pressure.
This paper not only presents a theoretical model that predicts the maximum heat transfer rate (Qmax) for a round shape heat pipe, but also obtains Qmax values with different lengths of the evaporator and the condenser. The effect of the different operating temperature and the different vacuum pressure of the heat pipe on the Qmax were also shown in this study. All these data will be a very good benchmark for the comparison of the experiment and the simulated results. From the experiment, the Qmax was rising with the increasing amount of the heat pipe diameter and the operating temperature. The deviation value of the Qmax between simulations and experiments are less than 15 %. It means that the Qmax model is a very good tool for designing the heat pipe performance ability. This research not only to predict, but also to discuss the vacuum pressure from the Heat pipe by destroy measurement. Of the results, the data from measured is very close to actually vacuum pressure, and it also has the repeatability in the same vacuum pressure from different inventory.

並列關鍵字

Heat Pipe ； Vacuum Pressure ； Maximum Heat Transfer ； Permeability ； Non-condensation Gas

參考文獻

32. 林哲興, 「微熱管溝槽液-氣接觸面相互影響之分析,」 私立中原大學，機械工程研究所碩士論文, 2004.

1. A. Faghri, Heat Pipe Science And Technology, Taylor & Francis, London, 1995.

5. G. Grover, T. Cotter, G. Erikson, 1964, “Structure of Very High Thermal Conductance,” J. Appl. Phys., Vol. 35, pp. 1990-1991, 1964.

6. T. P. Cotter, “Theory of Heat Pipe,” Los Alamos Scientific Laboratory Report No. LA-3246-MS, 1965.

15. J. Zhou, Z. Yao, J. Zhu, “Experimental Investigation of the Application Characters of Micro Heat Pipe,” Proc. 8th Int. Heat Pipe Conf., Beijing, China, 1992.