本研究分別以水、甲醇、乙醇與丙酮為熱管之工作流體分析管長、管徑、蕊材厚度與工作溫度四種不同之熱管參數對性能之影響。由分析結果得知，管長愈長，對總熱阻並無顯著影響，但最大熱傳量隨管長增加而降低。管徑愈大，熱阻愈低，最大熱傳量愈大。工作溫度愈高，以水為工作流體的熱管，其熱阻些微降低，最大熱傳量則愈大。以甲醇、乙醇為工作流體的熱管熱阻與最大熱傳量皆增加。但以丙酮為工作流體的熱管熱阻則隨溫度升高而增加，最大熱傳量則些微降低。蕊材厚度愈厚熱阻愈大，但最大熱傳量也愈高。在工作流體部分，以水為工作流體的熱管熱阻最低，最大熱傳量最高。 ;Heat pipe performance can be analyzed by two parameters, namely, thermal resistance and maximum heat transfer rate. In this study these two parameters are varied by changing four kinds of heat pipe parameters (Pipe length, pipe diameter, working temperature and wick thickness) and working fluids (water, methanol, ethanol and acetone) then analyzed by developing interactive computer software. Since empirical correlation can’t predict wick permeability and porosity accurately, experiments are carried out to find these values. Also the software is modified in accordance with the heat pipe experimental results at different heat pipe parameters to improve the prediction capability of computer software.
The heat pipe analysis results show that larger pipe length has no obvious effect on thermal resistance but reduces the maximum heat transfer rate. Larger pipe diameter, reduces the thermal resistance but increases the maximum heat transfer rate. Higher working temperature reduces thermal resistance but increases the maximum heat transfer rate when working fluid is water. For methanol and ethanol, as working temperature increases, thermal resistance increases and it also increases the maximum heat transfer rate. For acetone, as working temperature increases, thermal resistance increases but it reduces the maximum heat transfer rate. While for the case of wick thickness, as the wick thickness increases, both thermal resistance and maximum heat transfer rate increases. The result of working fluid analysis shows that except for water as working fluid, all other fluids has higher thermal resistance and lower maximum heat transfer rate.
