- 學位論文
鋼鐵廠中燃氣管線網路之模擬與分析
Modeling and Analysis of the Fuel-gas Pipeline Network in A Steel Mill Plant
摘要
煉鋼廠中的高爐煉鐵會產生高爐氣；轉爐在高溫下經過還原反應煉鋼製程時會產生轉爐氣，兩種燃料氣都包含高熱值的氫氣與一氧化碳，因此還能再燃燒產生能量，均透過環狀管線網路輸送至各需求單元作為燃料氣使用或儲存槽暫存，燃料氣不足時，儲存槽亦可釋出儲存的燃料氣補充。 本研究假設在一個充滿高爐氣與轉爐氣的燃氣環狀管線中進行模擬，透過Hardy-Cross疊代方法計算質量平衡、動量平衡與能量平衡，建立環狀燃氣管網的輸送模型，並針對數種常見的操作情境進行環狀管網壓力、流向分佈與熱值的分析。 本研究分別模擬並分析以下多種情況：一號轉爐在原位置之七種操作情境，另外還有一號轉爐在擬議中新位置之三種操作情境。在原位置之七種操作情境分析中，結果顯示不同操作情境會導致不同的流向分佈、不同的起點與終點、高爐儲存槽不同的使用狀況。在擬議中新位置之三種操作情境中，結果顯示改變位置會導致不同的流向分佈與影響各使用單元的熱值。經過調整各單元的流量，能讓各使用單元的熱值維持原樣。另外分析轉換操作情境時，各管線流量隨時間的變化，各單元供應與需求熱值隨時間變化，以利未來預測操作情境。 最後檢視各管線是否會有因為積碳而使管徑縮小，進而影響環路壓力與流動分佈，結果顯示右下角的管線長期流量偏小，容易累積並使管徑縮小，但右下角管線之管徑本來就比較大，因此並不會對此環路壓力造成影響。
並列摘要
The blast furnace and the basic oxygen furnace are two typical units in a steel mill plant to produce pig iron and steel respectively. A lot of blast furnace gas (BFG) and Linz-Donawitz gas (LDG) are also produced meanwhile. Both two gases are included hydrogen and carbon monoxide with high heating value which is also called fuel gas. The fuel gas is usually used a supplement heat supply in a steel mill plant. In this work, the BFG and the LDG are transported to various demand units though a pipeline network. Mass balance, momentum balance and energy balance are taken into consideration. A mathematical model of the fuel gas pipeline network is established by Hardy-Cross method to explore the distribution of fuel gas under different operation scenarios. This model can analyze the fuel gas flow direction, flow rate, pressure drop and heating values of each unit in pipeline network under different operation scenarios. Seven operation scenarios are discussed in first part and three operation scenarios are discussed in second part. In first part, it shows that different flow pattern, different starting node and end node, BFG with supply or demand unit are affected by different operation scenarios. In second part, it shows that changing the location of #1 LDG results in different flow pattern and affects heating values of each demand unit. By adjusting the demand flow rate of the demand units, it can make the heat load of each unit identical. Flow rate distribution variation by varying operation scenario can be obtained, too. Besides, flow rate of pipelines at the lower right corner is low which may result in pipeline shrinkage. However, the diameter of pipelines at the lower right corner is large. Thus, it affect pressure drop slightly.