PLC在火电厂吹灰系统中的应用_毕业设计.doc

本科生毕业设计说明书（毕业论文） 题 目：PLC在火电厂吹灰系统中的应用 PLC在火电厂吹灰系统中的应用 摘 要 锅炉运行过程中各部分受热面都会有积灰，积灰不仅影响传热效果，严重时还会形成结焦影响锅炉寿命，甚至损坏受热面。因此在火电厂生产过程中使用吹灰控制系统定期对锅炉的炉膛及烟道进行吹扫，以提高锅炉运行的稳定性和经济性。 本文针对锅炉受热面积灰、结渣污染危害严重的普遍现象，将可编程序控制器应用于吹灰控制系统。对吹灰系统的结构和功能进行了分析，根据吹灰器布置的位置和数目，本次设计采取自动+手动+就地手动的操作方式，吹灰器的运行方式采取按烟气方向依次运行的工作方式，这样可以减小吹灰器吹灰时对锅炉的负荷影响。针对吹灰系统及工业自动化的需求，引入西门子公司的S7-200系列可编程控制器进行编程和调试。本设计主要内容包括以下部分：1、介绍吹灰系统的发展过程及应用现状。2、分析火电厂吹灰系统的工艺流程。3、吹灰系统中设备的选型及设计。4、利用编程软件进行程序设计与功能实现。 关键词：吹灰系统，可编程控制器，梯形图，应用 Application of soot blowing system in thermal power plant based on PLC Abstract There is much dirt at many heated—surface in the running course of boiler. It is not only influencing heat transmission effect. So the boiler soot blowing HYPERLINK /s?wd=soot%20blowing control system is adapted to the produce course of Electric Power Station. In order to improve the stability and economy of boiler operation. In this paper, according to the serious and universal pollution problem caused by fouling and slagging of the boiler heating surface, the programmable controller is applied to blowing control system. Operation mode: automatic mode, manual mode or local mode will be selected, according to the location and number of soot blowers arranged. According to the flue gas direction, soot blowers will run in turn, which can reduce soot blowing impact on the boiler load. With the demand according to the soot blowing system and industrial automation, we have selected the S7-200 PLC series to do programming and debugging. This thesis mainly includes the following parts: 1,the development process of the soot blowing system is introduced in this paper and application status. 2,Analyze the process of soot blowing system in thermal power plants .3,Equipment selection and design in soot blowing system. 4,the use of programming software for program design and function implementation. Key words: soot blowing system, Programmable Logic Controller, Ladder Diagram, Application 目录 TOC \o 1-3 \h \z \u HYPERLINK \l _Toc27109 摘