基于PLC的工业污水处理控制系统的设计毕业论文.doc

基于PLC的工业污水处理控制系统的设计 姓 名：司晓峰 基于PLC的工业污水处理控制系统的设计 摘 要 目前，我国大多数污水处理控制系统自动化水平不高、安全性低、管理不当，效率普遍低于世界标准。污水处理系统中的曝气过程控制、数据通讯和监控管理是急需解决的主要问题。中国污水处理自控系统相对落后，污水处理成本居高不下，污水厂排放的处理过的污水的水质不稳定，所以如何建立有效的自控系统，优化运行效果，减少运行费用，具有重要意义。 本文介绍了工厂污水处理的基本工艺和流程，并通过研究设计一套基于PLC控制的污水处理系统。文章首先介绍了基于PLC污水处理控制系统的工艺及相关流程，控制系统硬件结构及设计、工作原理以及设计PLC控制系统的基本原则和步骤，来说明PLC在污水处理过程中的应用。先根据污水处理要求设计了设备的电器控制与自动控制线路，主要包括设备的启停、状态信号故障信号、和信号采集等，最后按照工艺要求设计PLC控制系统，其中包括PLC的选型、系统资源配置以及按照污水处理工艺编制PLC程序。 关键词：污水处理，PLC，工艺流程 Design of Sewage Treatment System Controlled by PLC With the rapid development of community economic technology and the constant improvement of the level of living in our country, the pollution of water becomes more and more serious. the sewage come from industry and town living increase continuously, but the city’s equipments which are used to drain sewage and dispose sewage are insufficient and some harmful substance which be not disposed were directly or indirectly pour into the river, then arose water pollution and appear to the problem about the aquatic environment’s pollution. While PLC has series of merits such as: mature technique, fine universal property, high reliability, flexible to install, convenient to expand, excellent cost performance, etc, which have enabled it gain a more and more widespread application in industrial control. This paper will mainly introduce the composition and function of the automatic control system in sewage treatment plants and several problems that may occur in the practical use of the system and the possible solutions to them. Since the transformation by employing PLC control system in sewage treatment, the reliability of automatic control has been advanced, which has not only reduced workers’ work intensity, but also improved the operational efficiency of the sewage treatment plants, thus has made the reliable administration of manufacturing in sewage treatment plants possible. Key words: PLC, Sewage treatment, SBR reaction 目 录 1 绪 论 1 1.1工业污水处理的国内外现状 1 1.2课题的背景