- 學位論文
高壓蒸汽鍋爐控制系統穩定操作的策略
The Strategy of Stable Operation for High Pressure Steam Boiler
摘要
鍋爐是熱能及熱動力之主要來源，非常廣泛的應用於製程，亦是火力發電渦輪機的主要動力來源。鍋爐控制是典型的多個嚴重非線性控制系統，其反應非常快速劇烈，需靠良好的控制策略與管理，以應變各控制變數間互相的影響，因此在系統中各控制器間的關係與控制模式顯得非常重要。當負載變化時，汽鼓內蒸汽隨著負載變化所造成液位表面驟沸，液位高度因震盪快速變化，使汽鼓液位產生虛假水位的現象，此現象會造成飼水泵及燃燒控制非預期的改變，使得系統產生不穩定易引起系統之燃料、飼水、送風等設備之能源損耗及工安事件。 本論文以某化工廠之熱動力來源之鍋爐模型，做整體系統性探討及模擬，利用Z-N法找出PID控制較適合之參數後，應用於鍋爐之程序控制。本論文則以套裝軟體SimACS開發動態模擬系統，包含了汽鼓、燃燒系統、送風機、脫氣槽、煙道氣等組合之系統模型的演算模組，以較完整系統性的考慮各種參數相互間之影響關係。進行模擬結果後，在多次調整各控制器最適的參數，以及各控制器間控制策略之組合後，得到穩定的蒸汽品質，可做為未來效率評估的基準。
並列摘要
Boiler is providing heat source of thermal and thermal dynamic energy in industry, especially in electrical generation application. Boiler control system is complex with multi input and output server non-linear system, violent in response and inter-influence between each control variable and constant. The purpose of system stability operation is base on control the boiler safety, reliably, and efficiently. Once loading changed, interaction with firing rate control due to imbalance between steam flow and feedwater flow will cause steam drum level have swell and shrink, incorrect measure would trouble the control system into un-control or oscillation condition. Therefore, operator will be jeopardized and energy will loosen more. For this reason, find the control method in control in advanced is more important for stability operation. This thesis utilizes SimACS engineering develop software to establish boiler dynamic model and simulate the situation of loading changing in superheat steam. Whole model are integrated and considered with deaerator, steam drum, burn control system, flue gas, blower, pump…etc.. After simulated and discussed, found and concluded at one suitable parameter and control strategy will make the boiler control system operation in steady status when superheat steam loading is changing.