系統識別號 | U0002-1907200512002600 |
---|---|
DOI | 10.6846/TKU.2005.00395 |
論文名稱(中文) | 焙炒爐的熱對流分析 |
論文名稱(英文) | The heat transfer analysis of the rotary kiln with heat convection |
第三語言論文名稱 | |
校院名稱 | 淡江大學 |
系所名稱(中文) | 機械與機電工程學系碩士班 |
系所名稱(英文) | Department of Mechanical and Electro-Mechanical Engineering |
外國學位學校名稱 | |
外國學位學院名稱 | |
外國學位研究所名稱 | |
學年度 | 93 |
學期 | 2 |
出版年 | 94 |
研究生(中文) | 蔡秉均 |
研究生(英文) | Bing-Jiun Tsai |
學號 | 692342230 |
學位類別 | 碩士 |
語言別 | 繁體中文 |
第二語言別 | |
口試日期 | 2005-06-24 |
論文頁數 | 64頁 |
口試委員 |
指導教授
-
顏政雄
委員 - 潘榕光 委員 - 葉豐輝 |
關鍵字(中) |
流場效應 熱傳導係數 有限元素軟體 紊流流場 |
關鍵字(英) |
field flow thermal conductivity ANSYS turbulent flow laminar flow rotary kiln temperature distribution |
第三語言關鍵字 | |
學科別分類 | |
中文摘要 |
本論文主要探討流場效應與熱對流引生焙炒爐溫度之變化,研究在不同的流場流速下之焙炒爐溫度場的分佈情形,內容分為實驗量測與數值分析兩部分。在實驗方面,量測含水率12% 芝麻在溫度5~60℃之間的熱傳導係數,並以數值方法求得K值: K= 0.0604 W/m℃ 由於12% 含水率下芝麻的熱傳導係數K值變化很小,因此採用平均值,作為模擬分析中的材料參數。 數值分析方面,使用ANSYS有限元素軟體進行模擬分析,分別使用三種不同元素與運算方式來比對有無對流條件與不同流場流速下溫度場的差異。初步分析得到在僅有熱傳導效應下的爐體較有流場與對流效應的平均溫度高出約50℃ 且後者爐內溫差較小,表示熱對流效應對溫度場具有影響性。進一步的分析在討論填充芝麻後,不同流場流速下溫度場的差異,分析得到在紊流流場下其爐內溫差約2.6℃較層流流場的21℃要小,但在平均溫度上卻低了約20℃;由此可知流場流速對溫度分佈有正面影響,但會損失些許能量。 |
英文摘要 |
The heat transfer modes consist of conduction, convection and radiation. Conduction and convection are the most important heat transfer modes within a rotary kiln. The heat transfer analysis considering only conduction, as former research of our project, is improved in this paper. The flow field, convection and conduction effects are considered and analyzed in this paper. This paper consists of the experimental and the numerical parts. In the experimental part, the KD-2 analyzer is used to measure the thermal conductivity of the sesame seeds with 12% moisture content. The thermal conductivity, 0.0604 W/m℃ is obtained for the numerical analysis. The software, ANSYS is chosen for numerical analysis. The simulation work is divided into two cases. It is found in the first case, by comparing the temperature fields between heat conduction only and flow field plus convection, the temperature distribution is quite different. The results from the second case, which is a comparison between different flow velocities in the rotary kiln, the temperature for turbulent flow is about 20℃ lower than for laminar flow. The temperature distribution for turbulent flow is more flat and is advantageous for our rotary kiln. |
第三語言摘要 | |
論文目次 |
目錄 中文摘要..........................................Ⅰ 英文摘要..........................................Ⅱ 目錄..............................................Ⅲ 圖目錄............................................Ⅴ 表目錄............................................Ⅶ 符號定義對照表....................................Ⅷ 第一章 緒論.......................................1 1.1 研究動機與目的................................1 1.2 文獻回顧與探討................................2 1.2.1 焙炒爐內顆粒之運動模式......................2 1.2.2 焙炒爐內顆粒之填充率........................3 1.2.3 焙炒爐內顆粒之進給率........................4 1.2.4 焙炒爐中的熱傳模式..........................4 第二章 芝麻熱傳導係數測定.........................7 2.1 芝麻熱傳導係數................................7 2.2 熱傳導係數測定器的熱傳原理....................7 2.3 實驗設備......................................9 2.4 實驗步驟.....................................13 2.5 實驗流程.....................................13 2.6 實驗結果.....................................15 第三章 數值分析.................................17 3.1 有限元素法...................................17 3.2 ANSYS分析步驟流程圖..........................19 3.3 ANSYS流程分析................................20 3.4 焙炒爐的幾何及參數設定.......................26 3.4.1空爐分析.....................................26 3.4.2填充芝麻後分析...............................28 3.5 熱傳分析基礎理論.............................35 3.6 熱傳導.......................................35 3.7 熱對流.......................................40 3.8 熱輻射.......................................41 第四章 分析結果..................................43 4.1 空爐的溫度場分析結果.........................43 4.2 填充芝麻後的分析結果.........................48 4.2.1爐壁溫度分佈.................................48 4.2.2焙炒爐內溫度.................................54 4.3 不同流速下溫度場的比較.......................57 第五章 結論與建議................................60 5.1 結論.........................................60 5.2 實驗量測探討.................................60 5.3 分析的探討...................................61 參考文獻..........................................63 圖目錄 圖1-1 :顆粒運動模式圖.............................2 圖1-2 :顆粒分層模式圖.............................4 圖1-3 :旋轉式焙炒爐熱傳方式截面圖.................5 圖2-1 :中心線熱源法示意圖.........................9 圖2-2 :恆溫循環水槽..............................10 圖2-3 :抽取式樣品容器............................10 圖2-4 :熱傳導係數測定器..........................11 圖2-5 :濕度分析平衡儀............................12 圖2-6 :實驗設備示意圖............................13 圖3-1 :Solid 70元素..............................20 圖3-2 :Fluid 116 元素............................21 圖3-3 :Surf 152 元素.............................21 圖3-4 :Fluid142元素..............................23 圖3-5 :形狀不佳之元素............................25 圖3-6 :焙炒爐的計算模型之側視圖..................27 圖3-7 :焙炒爐幾何估算截面........................29 圖3-8 :焙炒爐數值計算截面........................30 圖3-9 :填充後焙炒爐模型側視圖....................34 圖3-10:控制體積中一維熱傳........................36 圖3-11:控制容積中三維熱傳導......................38 圖3-12:熱對流的邊界層............................40 圖4-1:兩種MODEL的上視圖..........................44 圖4-2 :流場與對流效應下的焙炒爐溫度分佈(側面)....45 圖4-3 :熱傳導為主的焙炒爐溫度分佈(側面)..........46 圖4-4 :流場與對流效應下焙炒爐出口端溫度分佈......46 圖4-5 :熱傳導為主的焙炒爐出口端溫度分佈..........47 圖4-6 :流場與對流效應的焙炒爐中心溫度分佈........47 圖4-7 :流場速度0.05 m/s,爐壁外側溫度與流場圖....49 圖4-8 :流場速度0.05 m/s,爐壁外側溫度分佈圖......50 圖4-9 :流場速度0.1 m/s,爐壁外側溫度與流場圖.....51 圖4-10:流場速度0.1 m/s,爐壁外側溫度分佈圖.......52 圖4-11:流場速度1 m/s,爐壁外側溫度與流場圖.......53 圖4-12:流場速度1 m/s,爐壁外側溫度分佈圖.........54 圖4-13:流場速度0.05 m/s,爐內溫度圖..............55 圖4-14:流場速度0.1 m/s,爐內溫度圖...............56 圖4-15:流場速度1 m/s,爐內溫度圖.................57 圖4-16:不同速度場下的溫度分佈比較圖..............58 圖4-17:不同流場流速爐壁側面溫度分佈..............59 表目錄 表1-1 :運動方式分類...............................3 表4-1 :傳導與流場及對流效應的比較................43 表4-2 :流場速度0.05 m/s,爐壁外側的溫度值........49 表4-3 :流場速度0.1 m/s,爐壁外側的溫度值.........51 表4-4 :流場速度1 m/s,爐壁外側的溫度值...........53 表4-5 :不同速度場下的最高溫與最低溫..............58 表5-1 :前端與後端溫度差比較......................62 表5-2 :不同流速的平均溫度比較....................62 |
參考文獻 |
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