臺灣博碩士論文加值系統

本研究旨在針對化學工廠中之高壓蒸汽系統之輸送進行深入動態分析。本研究將由最基本的統御方程式開始建立流體模型，其後在傳統隱式法的基礎下提出了迴圈式隱式法，此一迴圈式隱式法更為適合應用在大型蒸汽系統的數學解析方法。迴圈式隱式法在經過與特徵法的比較與分析後，確定了其適用性，因此本研究將此方法應用到蒸汽系統上。
過去文獻主要研究大都侷限於單管系統的動態分析，但在實際工廠中，會面臨的還有更複雜的環狀系統。本研究中提出了將哈迪‧克勞斯法與迴圈式隱式法進行結合的一個運算方法，使其可以用來分析與模擬環狀蒸汽分配系統的動態分析。最後將此種結合過後的方法應用到數個虛擬的簡單範例，與一個真實的大型石化廠案例。此種分析可以用來預測不同操作狀況下的波動情形，提供現廠人員操作的一個參考，亦可用於模擬不同操作方式下的優劣，對於提升高壓蒸汽管網的操作效益有莫大的助益。

The mathematical models for unsteady pipeline networks play an important role in the design of petrochemical plants, hydraulic power machines, long distance pipelines, etc., and have become popular in these industry due to the development of high-speed computers.
An iterative implicit method is proposed in this research to solve the continuity, momentum and energy equations in an unsteady, non-isothermal and compressible steam pipeline. The Newton-Raphson method is used as an algorithm to solve the finite-difference equations of a steam pipeline. The modified Hardy-Cross method is applied to the calculation of network system.
A set of nonlinear equations have to be solved simultaneously in traditional fully implicit methods, which are inappropriate to be used in a complex network system. Hence, a sequentially iterative fully implicit method has been propounded to deal with the nonlinear equations. Several cases are completed by the presented iterative fully implicit method and the simulation results are compared with existing characteristics methods.
For network systems, the present work proposes a method which combines the iterative fully implicit method that has been used in a single pipeline with the modified Hardy-Cross method and several examples are completed. The transient analysis of a network system is more practical than a single pipeline in a large refinery, therefore, the present study gives a simple method which can quickly have a deep look into the steam transient response.

口試委員會審定書 #
致謝 I
中文摘要 II
ABSTRACT III
目錄 IV
圖目錄 VI
表目錄 IX
第一章 緒論 1
1.1 前言 1
1.2 文獻回顧 2
1.3 研究動機 2
1.4 組織架構 3
第二章 蒸汽管網數學模型與解析方法 4
2.1 數學模型之建立 4
2.1.1 基本假設 4
2.1.2 統御方程式 4
2.2 數學解析方法 8
2.2.1 牛頓法 8
2.2.2 特徵法 9
2.2.3 隱式法 13
2.2.4 迴圈式隱式法 14
第三章 單管系統分析模擬 16
3.1 蒸汽無熱傳單管系統 16
3.1.1 快速變化系統 16
3.1.2 緩慢變化系統 20
3.2 蒸汽有熱傳單管系統 23
第四章 蒸汽網絡系統分析模擬 25
4.1 流體輸送系統 25
4.2 Hardy Cross方法 26
4.3 蒸汽網絡系統 30
4.3.1 蒸汽系統運算流程 30
4.3.2 樹枝狀系統 33
4.3.3 環狀網絡系統範例一 37
4.3.4 環狀網絡系統範例二 40
4.3.5 環狀網絡系統範例三 43
第五章 結論與未來展望 60
5.1 結論 60
5.2 未來展望 61
參考文獻 62
附錄A 64
蒸汽密度表示式 64
蒸汽黏度表示式 65
總包熱傳係數表示式 66

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