铁岭电厂机组汽包水位控制系统设计毕业设计论文

铁岭电厂#3机组汽包水位控制系统设计

摘 要

本文针对给水调节系统的被控对象动态特性、热工测量信号、调节机构特性，分析了三冲量给水控制系统的结构及工作原理，实现单元制给水全程控制系统应考虑的问题及控制方案。

300MW机组汽包水位系统的构成原理和控制功能，系统的总体结构、工作原理、控制过程、系统切换方式、控制逻辑、调试及参数整定原则。300MW机组汽包水位控制系统，采用两台汽动给水泵和1台启动/备用电动给水泵供水。控制方案采用单/三冲量结合，在低负荷时采用单冲量控制，在高负荷时采用三冲量控制,实现了全程给水自动控制。该系统的结构设计合理、功能完善、使用可靠，实现了启动初期锅炉进水直至停机锅炉放水全工况下汽包水位的控制，大大的减少了运行人员，达到了减员增效的目的，具有积极的推广应用价值。

关键词 汽包水位控制，单冲量，三冲量，全程给水自动控制

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沈阳工程学院毕业设计（论文）

Abstract

According to the water supply control system of the controlled object dynamic characteristic, thermal measurement signal, adjusting mechanism characteristics, analyzed three impulse feed-water control system structure and working principle, implementation unit feedwater control system should consider the problem and control scheme.300MW full-range feed-water control system of the composition 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 combination, 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

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铁岭电厂#3机组汽包水位控制系统设计

目 录

摘要 .................................................................................................................................................. I Abstract ......................................................................................................................................... II 1 引言 ........................................................................................................................................ - 1 - 1.1 课题背景及选题意义 ..................................................................................................... - 1 - 1.1.1 自动控制技术在电厂的应用 .................................................................................. - 1 - 1.1.2 火电厂自动化的内容 ................................................................................................... 1 1.2 本设计研究的主要内容 ................................................................................................. - 2 - 1.3 火电厂基本生产过程 ..................................................................................................... - 3 - 1.4 汽包水位控制系统简介 ...................................................................................................... 4 2 给水被控对象的动态特性 ......................................................................................................... 6 2.1 汽包水位的动态特性 .......................................................................................................... 6 2.2各种扰动下水位变化的动态特性 ....................................................................................... 7 2.2.1 给水流量扰动下对象的动态特性 ............................................................................... 7 2.2.2 蒸汽流量扰动下对象的动态特性 ............................................................................... 8 2.2.3 炉膛热负荷扰动下对象的动态特性 ........................................................................... 9 3 铁岭电厂#3机组汽包水位控制系统设计 .............................................................................. 10 3.1 给水控制系统总体方案的确定 ........................................................................................ 10 3.2 给水控制系统设计 ............................................................................................................ 10 3.2.1 汽包水位控制系统基本任务 ..................................................................................... 10 3.2.2 给水控制系统原理图 ................................................................................................. 11 3.3 汽包水位控制系统控制策略设计 .................................................................................... 11 3.3.1 汽包的工作原理 ......................................................................................................... 12 3.3.2 影响汽包水位变化的因素 ......................................................................................... 12 3.3.3 汽包水位的测量 ......................................................................................................... 13 3.4 测量信号的自动校正 ................................................................................................... - 14 - 3.4.1 水位信号的压力校正 ............................................................................................ - 14 - 3.4.2 过热蒸汽流量信号的压力、温度校正 ................................................................ - 15 - 3.4.3 给水流量信号的温度校正 .................................................................................... - 15 - 4 铁岭电厂#3机组汽包水位控制SAMA图分析 ............................................................... - 17 - 4.1 给水全程控制的关键问题 ........................................................................................... - 17 - 4.2 控制回路SAMA图分析 ............................................................................................. - 17 - 4.2.1 热工信号的测量 .................................................................................................... - 17 - 4.2.2 旁路给水控制 ........................................................................................................ - 20 - 4.2.3 电动泵的控制 ............................................................................................................. 20 4.2.4 汽动泵的控制 ............................................................................................................. 21 4.2.5 单冲量/三冲量转换 .................................................................................................... 22 5 铁岭电厂#3机组全程给水控制过程分析 .............................................................................. 24 5.1 串级三冲量汽包水位控制系统 ........................................................................................ 26 5.1.1 汽包水位控制概况 ..................................................................................................... 26

III

沈阳工程学院毕业设计（论文）

5.1.2 串级三冲量汽包水位控制系统的工作原理 ............................................................. 27 5.2 调节器的选择 .................................................................................................................... 28 5.3 串级三冲量汽包水位控制系统的参数整定 .................................................................... 29 5.3.2 主、副调节器的参数整定 ......................................................................................... 29 5.3.2 前馈通路的设计 ......................................................................................................... 31 总结 ............................................................................................................................................... 33 致谢 ............................................................................................................................................... 34 参考文献 ....................................................................................................................................... 35 附录 ............................................................................................................................................... 36 A1.1 给水系统SAMA图1 ........................................................................................................ 36 A1.2 给水系统SAMA图2 ........................................................................................................ 37 A1.3 给水系统SAMA图3 ........................................................................................................ 38 A1.4 给水系统逻辑图1 .............................................................................................................. 39 A1.5 给水系统逻辑图2 .............................................................................................................. 40 A1.6 给水系统逻辑图3 .............................................................................................................. 41 A1.7 给水系统逻辑图4 .............................................................................................................. 42

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