基于PLC的城市污水处理系统.doc

I 摘要随着城市的快速发展,环境问题也越来越严重。城市污水是破坏环境的一个主要的因素,目前我国城市污水处理系统相对落后,污水处理成本高,所以如何建立有效的自动控制系统,减少运行费用,具有重要意义。本文论述了城市污水处理系统的基本工艺和流程,并设计了一套基于 PLC 控制的城市污水处理系统。本系统包括硬件设计,软件设计和监控组态设计三个方面,实现了中小型城市的污水处理自动控制和远程监控。首先介绍了 PLC 控制系统的硬件结构、工作原理以及设计 PLC 控制系统的基本原则和步骤,然后以 SBR 污水处理工艺为例, 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气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 程序等。建立高度自动化污水处理厂,不仅可以加强整个系统的可靠性、准确性,还可以减少劳动强度,降低处理成本和节约能源。污水处理厂自动控制系统的建设将降低生产和维护成本,减轻生产及维护工人的劳动强度,并为生产工艺的进一步改进提供方便,具有很好的经济效益和社会效益。关键词: 污水处理; SBR ; PLC ;自动控制 II Abstract With the rapid development of the city,environmental problems are ing more and more sewage isa major factor in the destruction of the environment, the current sewage treatment system ofour city is relatively backward,the high cost of sewage treatment,so how to establish the automatic control system effectively,reduce the operation cost,has important significance. This thesis discusses the city sewage treatment technology and process,and design a set of city sewage treatment system based on PLC control. The system includes hardware design,software design and monitoring configuration design three aspects,to achieve automatic control of wastewater treatment for small and medium cities and remote ,the basic principles and steps PLC control system hardware structure,working principle and design of PLC control system,then SBR wastewater treatment process as an example to illustrate the application of PLC in the sewage treatment to the sewage treatment designed first electrical control equipment and automatic control circuit,including the start and stop equipment,status signals,fault signals and signal ,in accordance with the requirements of the design process PLC control system,including the configuration selection,system resources,and the PLC in accordance with the sewage treatment process,such as the preparation of the PLC a sewage treatment pl