【正文】 鐵嶺電廠 3機組汽包水位控制系統(tǒng)設計 I 摘 要 本文針對給水調節(jié)系統(tǒng)的被控對象動態(tài)特性、熱工測量信號、調節(jié)機構特性，分析了三沖量給水控制系統(tǒng)的結構及工作原理，實現(xiàn)單元制給水全程控制系統(tǒng)應考慮的問題及控制方案。 300MW 機組汽包水位系統(tǒng)的構成原理和控制功能，系統(tǒng)的總體結構、工作原理、控制過程、系統(tǒng)切換方式、控制邏輯、調試及參數(shù)整定原則 。 300MW 機組汽包水位控制系統(tǒng)，采用兩臺汽動給水泵和 1 臺啟動 /備用電動給水泵供水?？刂品桨覆捎脝?/三沖量結合，在低負荷時采用單沖量控制，在高負荷時采用三沖量控制 ,實現(xiàn)了全程給水自動控制。該系統(tǒng)的結構設計合理、功 能完善、使用可靠，實現(xiàn)了啟動初期鍋爐進水直至停機鍋爐放水全工況下汽包水位的控制，大大的減少了運行人員，達到了減員增效的目的，具有積極的推廣應用價值。 關鍵詞 汽包水位控制，單沖量，三沖量，全程給水自動控制 沈陽工程學院畢業(yè)設計（論文） II Abstract According to the water supply control system of the controlled object dynamic characteristic, thermal measurement signal, adjusting mechanism characteristics, analyzed three impulse feedwater control system structure and working principle, implementation unit feedwater control system should consider the problem and control fullrange feedwater control system of the position principle and control function, system structure, working principle, process control, system switching mode, control logic, debugging and parameters setting principle. 300MW unit boiler feedwater control system, using two steam feed pump and 1startup / standby electric feedwater pump. Control scheme using single / three impulse bination, when the low load using a single impulse control, in the high load using three impulse control, to achieve the full automatic feed water control. The system design and reasonable structure, perfect function, reliable use, realize the startup stage of boiler water to stop water under all operating conditions of boiler drum water level control, greatly reducing the operating personnel, achieved the goal of synergism of depletion of numbers, has positive popularization application value. Key Words Boiler feedwater control， Single impulse， Three impulse， All range feedwater automatic control 鐵嶺電廠 3機組汽包水位控制系統(tǒng)設計 III 目 錄 摘要 .................................................................................................................................................. I Abstract ..........................................................................................................................................II 1 引言 ........................................................................................................................................ 1 課題背景及選題意義 ..................................................................................................... 1 自動控制技術在電廠的應用 .................................................................................. 1 火電廠自動化的內容 ................................................................................................... 1 本設計研究的主要內容 ................................................................................................. 2 火電廠基本生產過程 ..................................................................................................... 3 汽包水位控制系統(tǒng)簡介 ...................................................................................................... 4 2 給水被控對象的動態(tài)特性 ......................................................................................................... 6 汽包水位的動態(tài)特性 .......................................................................................................... 6 各種擾動下水 位變化的動態(tài)特性 ....................................................................................... 7 給水流量擾動下對象的動態(tài)特性 ............................................................................... 7 蒸汽流量擾動下對象的動態(tài)特性 ............................................................................... 8 爐膛熱負荷擾動下對象的動態(tài)特性 ........................................................................... 9 3 鐵嶺電廠 3 機組汽包水位控制系統(tǒng)設計 .............................................................................. 10 給水控制系統(tǒng)總體方案的確定 ........................................................................................ 10 給水控制系統(tǒng)設計 ............................................................................................................ 10 汽包水位控制系統(tǒng)基本任務 ..................................................................................... 10 給水控制系統(tǒng)原理圖 ................................................................................................. 11 汽包水位控制系統(tǒng)控制策略設計 .................................................................................... 11 汽包的工作原理 ......................................................................................................... 12 影響汽包水位變化的因素 ......................................................................................... 12 汽包水位的測量 ......................................................................................................... 13 測量信號的自動校正 ................................................................................................... 14 水位信號的壓力校正 ............................................................................................ 14 過熱蒸汽流量信號的壓力、溫度校正 ................................................................ 15 給水流量信號的溫度校正 .................................................................................... 15 4 鐵嶺 電廠 3 機組汽包水位控制 SAMA 圖分析 ............................................................... 17 給水全程控制的關鍵問題 ........................................................................................... 17 控制回路 SAMA 圖分析 ............................................................................................. 17 熱工信 號的測量 .................................................................................................... 17 旁路給水控制 ........................................................................................................ 20 電動泵的控制 ............................................................................................................. 20