- 學位論文
利用MATLAB程式模擬公用蒸汽系統及其最佳化
Simulation and Optimization of Steam Power Plant by MATLAB
摘要
蒸汽系統是化工製程中主要的能量來源，用來供給發電、機械功或熱。製程工程師常常需要面對蒸氣系統中由於日常維修或者是緊急維修等等原因而使得設備無法正常運作，能夠充分了解工廠的操作狀態並且事前安排與評估，有效的提升操作效率並降低操作成本，成為相當重要的課題。本論文利用MATLAB開發蒸汽系統模擬程式，作為不過於複雜的蒸汽系統一種模擬與分析工具。本程式利用順序模法（Sequential modular approach）模擬蒸汽系統，其程式架構包括單元模組、系統流程圖以及計算腳本，利用系統流程圖及各個單元模擬模組組合成工廠流程後，放入計算腳本進行計算，最終送出結果。 本研究利用簡單蒸汽系統(蒸氣系統設計一)驗證此架構之可行性，發現其結果與商業軟體Aspen utilities planner幾乎一致；再用一個修改自實際工廠的蒸氣系統(蒸氣系統設計二)放入此程式中進行模擬，並且進行此工廠設計的最佳化探討。此蒸氣系統在沒有調整任何操作下總成本為3967 USD/h，調整蒸汽產量的分配後可以將成本降低至3854 USD/h，節省2.8%之蒸汽成本；進一步調整蒸汽渦輪的使用分配後，可再將成本降低至3765 USD/h，與基礎設計相比節省了5.1%，每年可以節省超過160萬美金。本論文所提出的程式具有較佳的修改彈性，增刪各種模組與添加各種輸出資訊後，可以使本程式更加實用。
並列摘要
Steam power plant is one of the main power sources for supplying mechanical power, electricity and heat in most typical chemical plants. A better understanding and proper management of steam distribution systems is crucial to maintain normal plant operation and to reduce the operating costs. In the simulation of steam power plants, equation oriented method usually takes a shorter calculation time. However, sequential modular approach (SMA) can provide more flexibility as well as simplicity when one is modifying the steam supply strategy of the power plant(Smith, 2005). These features of SMA are more suitable for steam power plants since modification of a utility system is more likely required during the whole lifetime of a plant. Though similar works can be achieved easily by using some commercial software such as Aspen Utilities Planner® (AUP), the use of SMA for power plant simulation and optimization is more economic if the studied utility system is not complicated. This work develops relevant models for several common units in a typical steam power plant, including boiler, steam turbine, valve, steam header, deaerator, pump and condenser. The developed basic models are then configured to simulate steam power plants by the method of SMA (Holmgren, 2006; Sun & Smith, 2015). The validated plant model can be used for simulation, analysis and optimization under various operating scenarios(Knopf, 2011). To demonstrate the developed plant simulation program, a typical steam power plant adopted from the literature (Nicholas & Jack, 2013)is established to compare with the result of the commercial software. The second steam system is based on actual plant, and total cost which include fuel cost and feed water cost is calculated. The total cost of this design is 3967 USD/h and with optimization the cost can be reduced to 3765 USD/h, which is a 5.1% cut-down.