余政靖臺灣大學：化學工程學研究所林明德Lin, Min-TeMin-TeLin2007-11-262018-06-282007-11-262018-06-282004http://ntur.lib.ntu.edu.tw//handle/246246/52291Despite recent advances in on-line composition measurement, temperature control remains as the major control configuration in distillation control. In a control of industrial ternary distillation column, with non-monotonic composition profile for the intermediate boiler, significant different closed-loop composition dynamics were observed when the temperature control tray was above or below the intermediate boiler composition turning point (e.g., above or below the tray where the intermediate exhibits a maximum). In this work, the role of direct temperature control is interpreted in the composition space. First, the temperature isotherm is established in the triangular composition space and the process direction and control direction can be clearly distinguished. Then, a quantitative measure, the traveling distance for all tray compositions under a specific temperature control configuration is defined and it can be computed directly from process and load transfer function matrices. Rigorous distillation column simulation confirms that a temperature control with a large traveling distance results in slow composition dynamics (e.g., considering the tray composition can be changed with a fixed rate) and, consequently, poorer control performance. The situation, the difference in the traveling distance, can become worse when we are controlling two temperatures in the column, dual-end temperature control. The interaction between temperature control and the column composition profile explains the conflict between the process direction and the control direction which leads to a large traveling distance. That is the result of quantitative measure can be visualized directly from the composition space provided with the isotherm of the temperature control tray. Next, the effects of product purities, relative volatilities, feed composition, and types of separation (e.g., direct, indirect, and transition separations) are explored and the results can be interpreted quantitatively with the traveling distance or qualitatively by inspecting the possible conflict between the process/control direction in the composition space. Finally, this concept is extended directly to composition control of multicomponent distillation systems. The results clearly show that improved temperature or composition control can be achieved by avoiding potential conflict in the process/control direction.摘要 I Abstract II 目 錄 III 圖索引 VI 表索引 XI 第一章 緒論 1 1.1前言 1 1.2文獻回顧 2 1.3研究動機 4 1.4組織章節 6 第二章 溫度與組成間的交互作用 7 2.1程序描述與設計 7 2.2 組成平面與等溫線間的關係 11 2.3 問題描述與觀察結果 14 2.4分析 20 2.4.1定性上的解釋 20 2.4.2 定量上的測量 24 2.5 雙點控制 31 2.6 結論 36 第三章 組成控制 39 3.1 前言 39 3.2 等組成線與組成平面的關係 39 3.3 單點控制 41 3.4 雙點控制(Dual-end control) 49 3.5 結論 54 第四章 其他因素的效應 59 4.1產品規格改變 59 4.1.1 程序描述 60 4.1.2 動態控制 62 4.1.3 結論 70 4.2相對揮發度改變 73 4.2.1程序描述 73 4.2.2動態控制 79 4.2.3結論 87 4.3進料組成改變 91 4.3.1 程序描述 91 4.3.2 動態控制 93 4.3.3 結論 96 第五章 其他分離程序的影響 101 5.1 程序描述 101 5.2動態控制 104 5.2.1 非直接分離(indirect separation) 104 5.2.2過渡分離(transition separation) 111 5.3結論 118 第六章 119 總結 119 參考文獻 1211581674 bytesapplication/pdfen-US溫度控制Temperature Controlthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/52291/1/ntu-93-R91524086-1.pdf