曝气生物滤池污水处理PLC控制系统设计.doc

曝气生物滤池污水处理PLC控制系统设计 摘 要 伴随城市建设步伐的加快，小区污水的回收利用是提高环境水资源质量和解决水资源短缺的重要措施。曝气生物滤池（简称BAF）作为一种新型的生物膜污水处理技术，具有处理效率高、出水水质较好以及运行管理方便等显著特点，近年来在污水处理系统中较受青睐。 本毕业论文以曝气生物滤池污水处理工艺为研究对象，利用自动化领域广泛使用的SIEMENS S7-300系列PLC对小区污水处理系统进行自动控制。文章首先介绍了曝气生物滤池污水处理的原理、工艺流程，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。再根据污水处理要求设计设备电气控制，主要包括风机和水泵的启停、状态信号和信号采集等。最后按照污水处理系统控制要求设计PLC控制系统，具体包括PLC选型、系统资源配置以及利用SIMATIC STEP 7 编程软件编写程序、程序编译等。 关键词：曝气生物滤池；小区生活污水处理；PLC；STEP 7；硬件配置；软件设计 BAF sewage treatment PLC control system design Abstract With the quickening pace of city construction, the plot sewage recycle water quality is to improve the environment and solve the shortage of water resources of the important measures. Biological aerated filters (abbreviation BAF) as a kind of new typed biofilm wastewater treatment technology, with high treatment efficiency and good water and operation management is convenient wait for a remarkable characteristics in wastewater treatment system in recent years more popular. My graduation paper uses BAF sewage treatment process as the research object, using automatic field extensive use of SIEMENS S7-300 PLC in series 300 residential sewage treatment system for automatic control. This article first introduces the biological aerated filters sewage treatment principle, process flow and PLC control system hardware structure, working principle and design PLC control system, the basic principles and steps. Again according to sewage treatment requirements design equipment electrical control, mainly including fan and pump start-stop, state signals and signal acquisition, etc. Finally according to wastewater treatment system control design requirement for PLC control system, specific include PLC selection, system resource allocation and utilization of SIMATIC programming with STEP 7 software programming, the program compiled, etc. Key words: BAF; Residential sewage treatment; PLC; STEP 7; Hardware