臺灣博碩士論文加值系統

本文針對一熱儲存之相變化材料18烷(C18H38)加入氧化鋁(Al2O3)奈米顆粒調製而成之相變化奈米材料，並針對其相關熱物性質包括：黏度係數、熱傳導係數、密度、比熱及潛熱隨溫度及重量濃度之變化情形進行實驗測定；並以實驗方式探討相變化奈米材料於直立矩形容器內等溫熔解時熱傳特性，本文探討直立矩形容器其物理模型為左/右垂直壁分別為等溫熱/冷壁面，其餘壁面均為絕熱壁面。在實驗上，分別改變冷熱壁溫度(40℃/24℃、40℃/26℃、40℃/27.5℃、36℃/26℃、32℃/26℃)及重量濃度(0%、5%、10%)，主要參數及範圍分別為：萊利數Ra=1710000~5670000；史蒂芬數Ste=0.037~0.108；次冷參數Sb=0.042~0.537。本文實驗結果顯示在矩形容器內相變化奈米材料在等溫熔解過程，其自然對流熱傳係數及熱儲存能力均呈現隨奈米顆粒重量濃度增加而降低，且亦低於純18烷之結果。

The present study considers a mixture of n-Octadecane and Al2O3 nanoparticles as a phase change nano material for the latent-heat thermal energy storage application Thermophysical properties of the PCM containing varies mass fractions of alumina particles were determined experimentally as a function of temperature. Moreover, melting heat transfer characteristics of the PCM dispersed with alumina particles were examined experimentally in a differentially heated vertical square enclosure with the relevant parameters in the ranges : Ra=1710000~5670000 ; Ste=0.037~0.108 and Sb=0.042~0.537. The heat transfer results indicate natural convection heat transfer in the melted region and thus the thermal energy storage efficiency tend to decrease markedly with increasing mass fraction of alumina particles in n-Octadecane.

第一章 序論 1
1-1 前言 1
1-2 文獻回顧 1
1-3 研究目的 6
1-4 本文架構 6
第二章 相變化奈米材料之製備與熱物性質量測 7
2-1相變化奈米材料 7
2-1-1介面活性劑 7
2-1-2相變化奈米材料之製備 8
2-2 熱物性質量測 8
2-2-1 DSC（Differential Scanning Calorimetry）之量測 8
2-2-2 比熱計算 9
2-2-3 黏度量測 10
2-2-4 熱傳導係數量測 11
2-2-5 密度之量測 11
2-3 量測誤差 12
第三章 矩形容器內相變化熱傳實驗模型與量測方法 15
3-1 熔解實驗模型與設備 15
3-1-1 實驗模型 15
3-1-2 實驗量測周邊系統 16
3-2 實驗方法與步驟 17
3-3 實驗數據換算 18
3-4 不準度分析 22
第四章 結果與討論 29
4-1 熱物性質量測結果 29
4-1-1 密度 29
4-1-2 動力黏度 30
4-1-3 潛熱及熔點溫度量測 30
4-1-4 熱傳導係數 31
4-1-5 比熱 32
4-2 方形容器內相變化奈米材料熔解熱傳過程結果 33
第五章 結論與未來方向 60
參考文獻 62
附錄A 不準度分析 65
附錄B 熔解實驗溫度變化 68
附錄C 熔解實驗熱壁輸入電功率變化 70
自述 71

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