毕业设计---基于PLC工业锅炉汽包水位控制系统的设计.doc

基于PLC工业锅炉汽包水位控制系统的设计
The Design of the Boiler Drum Water
Level Control System with PLC
摘要
锅炉是众多工业部门必不可少的重要动力设备。因此,锅炉往往成了不少工厂不可缺少的一部分。因而,对锅炉设备中的自动控制系统进行分析研究是必要的。锅炉水位控制系统是锅炉生产控制系统中最重要的环节。对锅炉生产操作如果不合理,管理不善,处理不当,往往会引起事故。这些事故中的大部分是由于锅炉水位控制不当引起的,可见锅炉汽包水位控制在锅炉设备控制系统中的重要性。
锅炉汽包水位是一个非常重要的被控变量。由于锅炉的水位调节过程难以建立数学模型,具有非线形、不稳定性、时滞等特点。传统的锅炉水位三冲量控制系统大都采用PID控制,其控制效果还可以进一步提高。而模糊控制不要求知道被控对象的精确模型,只需要操作人员的经验知识及操作数据,鲁棒性强,非常适合于非线性、滞后系统的控制。
关键词: 汽包水位; 模糊PID; 三冲量
Abstract
The boiler is numerous essential important power equipment of industrial department. So, the boiler has often e an indispensable part of many factories. Therefore, it is essential for automatic control system in the boiler equipment to research. The water level control system of the boiler is that the boiler produces the most important link in the control system. If the production operation of the boiler is unreasonable, it is improper to deal with, and will often cause the accident. The majority in these accidents is caused because of improper in control the water level of the boiler. That can see the importance in the equipment control system of the boiler of control of water level of steam dome of the boiler.
The auto-control of the drum water level is very important. The drum water level is an important variable to be controlled, it is hard to get the mathematic model of the water level with adjust process. It is characteristic of nonlinearity, instability and time lag. The traditional control mode of three-variable in the drum water level most use PID, the effect of it can be improved. The fuzzy control does not need precise mathematic model of the controlled object, it only needs the experience of operator and the date of operating it has good robustness and it fit to control the system with nonlinearity and lag.
Keywords: Drum water level, Fuzzy-PID, Three-variable
目录
摘要 I
ABSTRACT I
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3锅炉汽包水位的基本特性和汽包水位控制系统方案选择 3