余政靖臺灣大學:化學工程學研究所程建凱Cheng, Jian-KaiJian-KaiCheng2007-11-262018-06-282007-11-262018-06-282006http://ntur.lib.ntu.edu.tw//handle/246246/52346反應蒸餾塔是在單元設備裡結合反應與分離程序,藉此可提高某些化學反應系統的經濟效益。由於反應蒸餾具有多功(Multifunctional)的本質,這使得反應或分離原本的非線性特性更加複雜。因此相較於單一功能單元的動態,反應蒸餾塔之動態與控制行為較不明顯。本研究目的主要探討反應蒸餾塔非線性的動態行為,由於分離程序與化學反應的交互作用下,導致產品組成與操作變數之穩態增益出現變號(Sign Reversal)行為。以程序控制觀點來看,表示有右半平面的零位(RHP Zeros)的產生,也就是具有非最小相位的行為(Non-Minimum Phase Behavior, NMP)。一般在反應蒸餾塔穩態設計的例子,操作點大多設計在最大效能的附近。如此一來,小幅的操作點改變,可能會產生右半平面的零位。因此,多功程序之單元的控制架構設計顯得格外重要。首先,由化學反應的化學計量數平衡與質量平衡來看,反應蒸餾塔使用部分控制是一個理想的選擇。接著,分析不同控制架構的程序特性-部分控制下的線性行為、動態特性以及非線性程度,找尋最適當的控制架構。藉由上述提出的系統化方法,我們針對乙酸甲酯反應蒸餾系統來描述其控制架構設計。結果顯示所提出來的部分控制架構設計方法是可以達成可接受的控制品質。更重要的,這是在使用相當簡單控制系統所獲得的結果。Reactive distillation combines reaction and separation in a single unit, which provides substantial economic incentives for some chemical reaction systems. However, the multifunctional nature of the reactive distillation complicates already very nonlinear nature of either reaction or separation. Thus, the dynamics and control of reactive distillation are less obvious as compared to its single functional unit counterparts. The objective of this work is to explore the nonlinear dynamics of reactive distillation. The interaction between reaction and separation leads to possible “sign reversal” in the steady-state gains between the product compositions and typical manipulated inputs. In terms of process control, this implies the existence of right-half-plane (RHP) zeros, a non-minimum-phase (NMP) behavior. This is typically true as a near-optimal reactive distillation column design and, in many cases, the RHP zeros vary from zero to two in a small operating range. The situation worsens as the control structure grows larger, e.g., from 2x2 to 3x3 systems. Thus, the control structure design becomes important for this multifunctional unit. First, the stiochiometric of chemical reaction indicates that the “partial control” is an ideal candidate for reactive distillation control. Subsequently, the problem becomes the selection of controlled and manipulated variables. A systematic approach is proposed to select the most appropriate control structure. We analyze the process charaterictics of system - dynamic characteristic (NMP), nonlinearity measure, deviations of uncontrolled composition under setpoint and load changes. The methyl acetate example is used to illustrate the control structure design. The results clearly show that reasonable control performance can be achieved using partial control, provided with a careful control structure selection.致謝 I 摘要 III Abstract V 目錄 VII 圖索引 IX 表索引 XI 1 緒論(Introduction) 1 1.1前言 1 1.2文獻回顧 3 1.3研究動機 5 1.4組織章節 6 2 程序特性(Process Characteristic) 7 2.1系統探討–乙酸甲酯製程 7 2.2程序特性 11 2.2.1輸入型多重穩態 11 2.2.2動態特性 19 2.2.3多重穩態對控制的影響 21 2.2.4替續性的回饋測試(Relay Feedback Test) 24 2.2.5非線性量測(Nonlinear Measurement) 25 3 反應蒸餾系統控制-系統化的方法 27 3.1部分控制 27 3.2 Issues Addressed 30 3.2.1部分控制的線性行為 31 3.2.2操作點的動態特性 31 3.2.3非線性指數 31 4 乙酸甲酯反應蒸餾系統(MeAc Reactive Distillation) 33 4.1程序特性的分析 33 4.1.1部分控制的線性行為 34 4.1.2操作點的動態特性 36 4.1.3非線性指數量測 45 4.2 控制架構的選擇 46 4.2.1控制架構的分析 46 4.2.2控制塔板溫度的分析 50 4.3動態控制模擬 54 4.3.1RGA配對分析 55 4.3.2控制器參數調諧方法 55 4.3.3QR-xB FR-T2的控制模擬結果 56 4.3.4QR-xB FR-T39的控制模擬結果 58 4.3.5QR-xB FR-T12的控制模擬結果 59 4.4濃度量測的延遲時間對控制的影響 63 5 結論 67 參 考 文 獻 691254757 bytesapplication/pdfen-US反應性蒸餾非線性行為非最小相位的行為Reactive DistillationNonlinear BehaviorNon-Minimum-Phase反應性蒸餾系統的非線性動態行為研究Understanding Nonlinear Dynamic Behavior of Reactive Distillationthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/52346/1/ntu-95-R93524074-1.pdf