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基于PLC的化学水处理控制系统的设计论文.doc

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中国矿业大学毕业设计任务书 毕业设计题目: 电厂水处理系统的自动控制 毕业设计专题题目: 基于PLC的化学水处理控制系统的设计 毕业设计主要内容和要求: 调研、查阅相关的资料及文献 在调研、查阅相关的资料及文献基础上提出可行性系统设计 工艺流程的确定 硬件系统设计 plc编程 摘 要 随着火电机组向大容量、高参数发展,机组在起停中需要监控的项目不断增加。可以设想,如此繁多的辅机、阀门若由电厂运行人员手动操作,是难以完成机组的起停工作的,甚至导致事故的进一步扩大。由此可见,在大中型电厂应普遍进行顺序控制。机组顺序控制系统的英文全称是Sequential Control System,简称SCS。SCS包括主机的顺序控制和机组外围设备的顺序控制。机组主机的顺序控制可由可编程序控制器(PLC)实现,也可由集散控制系统实现。 电厂锅炉是生产中使用最广泛的设备之一,锅炉补给水的处理工作对确保电厂安全、经济运行有着重要意义,它是电厂运行中的一项重要技术基础工作。目前锅炉水处理工艺流程设计中最广泛使用的是离子交换法(化学处理法)和渗透法(物理处理法),传统的水处理过程中多为继电器和人工操作,系统故障多,劳动强度大,运行成本高。 本文介绍一种关于化学水处理工艺过程的PLC控制系统的设计,通过阐明了化学水处理的工艺及PLC控制系统各项功能,给出一种详细的设计方案。 关键词:PLC; 化学水处理; 控制系统 ABSTRACT With thermal power machine group to High Capacity, high parameter extend, needs for supervisory item of machine group at on-off are increasing without intermission . Imagining,if power plant operator operate so multitudinous auxiliary and valve only by hands, it is so difficult to finish machine teams on-off working, even result in more expanding of accident.We see, therefore,at cleanness defect type power plant should proceed prevalence sequential control.Its full name in english is sequential control system , that of machine group sequence control system ,for short scsScs include mainframes sequential control and machine group peripheral equipments sequential control .The sequential control of the machine group mainframe can realize not only by programmable controller(plc)but also by total distributed control system . It was one of the churn used most widely eqoupment on power plant online,boiler feedwater dispose working bore import sense on ensuring security and economical operation of power plant ,though it is one of important supporting technology wrought on power plant in-serviceNow that of boiler water treatment process design most extensively used,it was ion-exchange method(method of chemical treatment)and osmose process(physical treatment law),conventional water curing course much serve as RELAID and manhandle and manhandle,much s
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