臺灣博碩士論文加值系統

本文係以廢硫酸銅溶液為熱流體，以水為冷流體，採用蛇形盤管式熱交換器進行熱交換研究，於此採用熱流體連續進入攪拌槽操作，內置蛇形盤管，冷流體液連續地進入蛇形盤管，並進行攪拌以達到充分熱交換效果，同時偵測進、出口流體之溫度及蛇形盤管外表面溫度，進一步地探討操作變數對總括熱傳係數與個別熱傳係數之影響。由於廢硫酸銅溶液係由印刷電路板之電鍍液回收而得，若採用鋁製換法回收銅金屬會放熱，故溫度之控制及熱傳很重要，由於熱傳機構對於熱交換很重要有探討之必要。為達成目的，操作變數有冷流體之進口溫度(A)、冷流體之進口流率(B)、攪拌速率(C)、熱流體之進口溫度(D)及熱流體之進口流率(E)等共有5參數，各取4水準，依傳統實驗設計共有1024組實驗，難以進行，故採用田口實驗設計共有L16(45)=16組實驗，可探討操作變數對總括熱傳係數之影響。結果顯示實驗於40分鐘可達恆態操作，依恆態條件所得的數據可用於計算總括熱傳係數及個別熱傳係數，其結果為571.3-1280.9 W/m2•K間，由田口分析所得之最佳條件，其望大與望小分為A4B4C2D1E1及A4B1C1D4E4，經印證可得望大、小值分別為1334.4 W/m2•K與478.6 W/m2•K均達成達最佳目標。此外，於此獲得望大與望小參數重要性順序分別為D＞B＞E＞C＞A及B＞D＞C＞E＞A，表示熱流體之進口溫度(D)與冷流體之進口流率(B)較為重要，而冷流體之進口溫度(A)最不重要；此外於此計算所得之hi (在蛇形盤管內之個別熱傳係數)在708-2087.1 W/m2•K範圍；而ho(攪拌槽)在1453.0-5142.1 W/m2•K範圍，然而由個別熱傳係數計算所得之總括熱傳係數與直接計算(571.7-1287.6 W/m2•K)所得之數據極為接近，表示用以計算熱傳係數之方法具有可靠性。由個別熱傳係數及其熱阻分析，其中熱導熱阻小於10%，然而整體上R1在45.87%-84.52%之間，R2在9.71%-44.96%之間，故知熱阻主要發生在R1，不過仍然不能忽略各項熱阻對總括熱傳係數之影響。由於其在攪槽中之對流熱傳，有較高之熱傳係數，故其值高於hi之範圍，故其熱阻較小應是合理的。此外，由個別熱傳係數所得之經驗式，可估計總括熱傳係數，所得知結果可為設計冷凝器之參考。

This study employed a helical coil heat exchanger to explore the heat exchange using waste copper sulfate solution as hot fluid and water as cold fluid. The agitator tank is continuously filled with hot fluid while the cold fluid is filled into a built-in helical coil. The tank is stirred to achieve full heat exchange. The fluid temperatures at the inlet and outlet of the tank and the outside surface temperature of the helical coil are simultaneously measured. The influence of operation variables on the overall and individual heat transfer coefficients is discussed. The variables include the inlet temperature of the cold fluid (A), the inlet flow rate of cold fluid (B), stirring rate (C), the inlet temperature of the hot fluid (D), and the inlet flow rate of hot fluid (E). These five parameters have four levels. There are 1,024 experiments according to the traditional design of experiments, making them difficult to be performed. This study thus adopted the Taguchi experimental design method. Therefore, there were L16(4)5=16 experiments. The influence of operating variables on the overall heat transfer coefficient was discussed. The results show that steady-state operation can be achieved within 40 min of the experiment. The data derived from steady-state conditions can calculate the overall heat transfer coefficient, and the result is 571.3-1280.9 W/m2•K. The larger-the-better and smaller-the-better of the optimum conditions obtained by Taguchi analysis are A4B4C2D1E1 and A4B1C1D4E4. The validation results show that the larger-the-better and smaller-the-better values are 1334.4 W/m2•K and 478.6 W/m2•K, respectively. The optimal objectives are attained. Additionally, the orders of importance of larger-the-better and smaller-the-better parameters are D>B>E>C>A and B>D>C>E>A, respectively. This means that the inlet temperature of the hot fluid (D) and the inlet flow rate of cold fluid (B) are relatively more important, whereas the inlet temperature of the cold fluid (A) is the least important. The calculated hi (individual heat transfer coefficient inside helical coil) is 708-2087.1 W/m2•K; the ho (agitator tank) is 1453.0-5142.1 W/m2•K. The overall heat transfer coefficient calculated from the individual heat transfer coefficient is very close to the data obtained by direct calculation (571.7-1287.6 W/m2•K). It suggests that the method for calculating the heat transfer coefficient is reliable. The individual heat transfer coefficient and thermal resistance analysis show that the thermal conduction resistance is smaller than 10%, but the overall R1 is 45.87%-84.52%, and R2 is 9.71%-44.96%. Thus, the thermal resistance mainly occurs in R1, but the influence of various thermal resistances on the overall heat transfer coefficient should not be overlooked. The heat transfer coefficient is higher due to the convection inside the agitator tank. Therefore, the value is higher than the range of hi, and the lower thermal resistance is reasonable. In addition, the overall heat transfer coefficients can be evaluated by using empirical equations of individual heat transfer coefficients. The results can serve as a reference for designing condensers.

摘要 i
ABSTRACT iii
誌謝 v
目錄 vi
表目錄 viii
圖目錄 ix
第一章 緒論 1
第二章 文獻回顧 5
2.1熱傳資料 5
2.2個別熱傳係數 6
2.3個別熱傳係數 8
2.4總括熱傳係數 12
2.5田口實驗方法 14
2.5.1直交表 15
2.5.2信號雜訊比（Signal-to-Noise Ratio, S/N比） 15
第三章 總括熱傳係數之計算 17
3.1直接計算總括熱傳係數 17
3.2由個別熱傳係數計算總括熱傳係數 18
第四章 實驗步驟與方法 21
4.1實驗設計 21
4.2實驗方法與步驟 23
4.3溶液比熱及密度之決定 25
第五章 結果與討論 27
5.1總括熱傳係數 27
5.1.1直接計算 27
5.1.2由個別熱傳係數計算總括熱傳係數 29
5.2望大及望小及其印證 33
5.2.1望大分析 34
5.2.2望小分析 36
5.3最佳條件之印證 38
5.3.1望大值印證 38
5.3.2望小值印證 40
5.4熱傳機構分析 42
5.5熱傳係數關係式 45
5.5.1蛇形管之熱傳係數關係式 45
5.5.2攪拌槽之熱傳係數關係式 48
第六章 結論 51
參考文獻 52
附錄 54
附錄A實驗紀錄 54

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